Topical Administration of Somatostatin Prevents Retinal Neurodegeneration in Experimental Diabetes

PubMed Central

Hernández, Cristina; García-Ramírez, Marta; Corraliza, Lidia; Fernández-Carneado, Jimena; Farrera-Sinfreu, Josep; Ponsati, Berta; González-Rodríguez, Águeda; Valverde, Ángela M.; Simó, Rafael

2013-01-01

Retinal neurodegeneration is an early event in the pathogenesis of diabetic retinopathy (DR). Somatostatin (SST) is an endogenous neuroprotective peptide that is downregulated in the diabetic eye. The aim of the study was to test the usefulness of topical administration of SST in preventing retinal neurodegeneration. For this purpose, rats with streptozotocin-induced diabetes mellitus (STZ-DM) were treated with either SST eye drops or vehicle for 15 days. Nondiabetic rats treated with vehicle served as a control group. Functional abnormalities were assessed by electroretinography (ERG), and neurodegeneration was assessed by measuring glial activation and the apoptotic rate. In addition, proapoptotic (FasL, Bid, and activation of caspase-8 and caspase-3) and survival signaling pathways (BclxL) were examined. Intraretinal concentrations of glutamate and its main transporter glutamate/aspartate transporter (GLAST) were also determined. Treatment with SST eye drops prevented ERG abnormalities, glial activation, apoptosis, and the misbalance between proapoptotic and survival signaling detected in STZ-DM rats. In addition, SST eye drops inhibited glutamate accumulation in the retina and GLAST downregulation induced by diabetes mellitus. We conclude that topical administration of SST has a potent effect in preventing retinal neurodegeneration induced by diabetes mellitus. In addition, our findings open up a new preventive pharmacological strategy targeted to early stages of DR. PMID:23474487

Topical administration of somatostatin prevents retinal neurodegeneration in experimental diabetes.

PubMed

Hernández, Cristina; García-Ramírez, Marta; Corraliza, Lidia; Fernández-Carneado, Jimena; Farrera-Sinfreu, Josep; Ponsati, Berta; González-Rodríguez, Agueda; Valverde, Angela M; Simó, Rafael

2013-07-01

Retinal neurodegeneration is an early event in the pathogenesis of diabetic retinopathy (DR). Somatostatin (SST) is an endogenous neuroprotective peptide that is downregulated in the diabetic eye. The aim of the study was to test the usefulness of topical administration of SST in preventing retinal neurodegeneration. For this purpose, rats with streptozotocin-induced diabetes mellitus (STZ-DM) were treated with either SST eye drops or vehicle for 15 days. Nondiabetic rats treated with vehicle served as a control group. Functional abnormalities were assessed by electroretinography (ERG), and neurodegeneration was assessed by measuring glial activation and the apoptotic rate. In addition, proapoptotic (FasL, Bid, and activation of caspase-8 and caspase-3) and survival signaling pathways (BclxL) were examined. Intraretinal concentrations of glutamate and its main transporter glutamate/aspartate transporter (GLAST) were also determined. Treatment with SST eye drops prevented ERG abnormalities, glial activation, apoptosis, and the misbalance between proapoptotic and survival signaling detected in STZ-DM rats. In addition, SST eye drops inhibited glutamate accumulation in the retina and GLAST downregulation induced by diabetes mellitus. We conclude that topical administration of SST has a potent effect in preventing retinal neurodegeneration induced by diabetes mellitus. In addition, our findings open up a new preventive pharmacological strategy targeted to early stages of DR.

Theoretical studies of the transport properties in compound semiconductors

NASA Technical Reports Server (NTRS)

Segall, Benjamin

1994-01-01

This final report is an overview of the work done on Cooperative Agreement NCC 3-55 with the Solid State Technology Branch of the NASA-Lewis Research Center (LeRC). Over the period of time that the agreement was in effect, the principal investigator and, in the last three years, the co-principal investigator worked on a significant number of projects and interacted with members of the Solid State Technology (SST) branch in a number of different ways. For the purpose of this report, these efforts will be divided into five categories: 1) work directly with experimental electrical transport studies conducted by members of the SST branch; 2) theoretical work on electrical transport in compound semiconductors; 3) electronic structure calculations which are relevant to the electrical transport in polytypes of SiC and SiC-AlN alloys; 4) the electronic structure calculations of polar interfaces; and 5) consultative and supportive activities related to experiments and other studies carried out by SST branch members. Work in these categories is briefly discussed.

The atmospheric effects of stratospheric aircraft: A topical review

NASA Technical Reports Server (NTRS)

Johnston, Harold S.; Prather, M. J.; Watson, R. T.

1991-01-01

In the late 1960s the aircraft industry became interested in developing a fleet of supersonic transports (SSTs). Between 1972 and 1975, the Climatic Impact Assessment Program (CIAP) studied the possible environmental impact of SSTs. For environmental and economic reasons, the fleet of SSTs was not developed. The Upper Atmosphere Research Program (UARP) has recently undertaken the responsibility of directing scientific research needed to assess the atmospheric impact of supersonic transports. The UARP and the High-Speed Research Program asked Harold Johnston to review the current understanding of aircraft emissions and their effect on the stratosphere. Johnston and his colleagues have recently re-examined the SST problem using current models for stratospheric ozone chemistry. A unique view is given here of the current scientific issues and the lessons learned since the beginning of CIAP, and it links the current research program with the assessment process that began two years ago.

Takeoff certification considerations for large subsonic and supersonic transport airplanes using the Ames flight simulator for advanced aircraft

NASA Technical Reports Server (NTRS)

Snyder, C. T.; Drinkwater, F. J., III; Fry, E. B.; Forrest, R. D.

1973-01-01

Data for use in development of takeoff airworthiness standards for new aircraft designs such as the supersonic transport (SST) and the large wide-body subsonic jet transport are provided. An advanced motion simulator was used to compare the performance and handling characteristics of three representative large jet transports during specific flight certification tasks. Existing regulatory constraints and methods for determining rotation speed were reviewed, and the effects on takeoff performance of variations in rotation speed, pitch attitude, and pitch attitude rate during the rotation maneuver were analyzed. A limited quantity of refused takeoff information was obtained. The aerodynamics, wing loading, and thrust-to-weight ratio of the subject SST resulted in takeoff speeds limited by climb (rather than lift-off) considerations. Take-off speeds based on U.S. subsonic transport requirements were found unacceptable because of the criticality of rotation-abuse effects on one-engine-inoperative climb performance. Adequate safety margin was provided by takeoff speeds based on proposed Anglo-French supersonic transport (TSS) criteria, with the limiting criterion being that takeoff safety speed be at least 1.15 times the one-engine-inoperative zero-rate-of-climb speed. Various observations related to SST certification are presented.

Exhaust Nozzles for Propulsion Systems with Emphasis on Supersonic Cruise Aircraft

NASA Technical Reports Server (NTRS)

Stitt, Leonard E.

1990-01-01

This compendium summarizes the contributions of the NASA-Lewis and its contractors to supersonic exhaust nozzle research from 1963 to 1985. Two major research and technology efforts sponsored this nozzle research work; the U.S. Supersonic Transport (SST) Program and the follow-on Supersonic Cruise Research (SCR) Program. They account for two generations of nozzle technology: the first from 1963 to 1971, and the second from 1971 to 1985. First, the equations used to calculate nozzle thrust are introduced. Then the general types of nozzles are presented, followed by a discussion of those types proposed for supersonic aircraft. Next, the first-generation nozzles designed specifically for the Boeing SST and the second-generation nozzles designed under the SCR program are separately reviewed and then compared. A chapter on throttle-dependent afterbody drag is included, since drag has a major effect on the off-design performance of supersonic nozzles. A chapter on the performance of supersonic dash nozzles follows, since these nozzles have similar design problems, Finally, the nozzle test facilities used at NASA-Lewis during this nozzle research effort are identified and discussed. These facilities include static test stands, a transonic wind tunnel, and a flying testbed aircraft. A concluding section points to the future: a third generation of nozzles designed for a new era of high speed civil transports to produce even greater advances in performance, to meet new noise rules, and to ensure the continuity of over two decades of NASA research.

Somatostatin and its 2A receptor in dorsal root ganglia and dorsal horn of mouse and human: expression, trafficking and possible role in pain

PubMed Central

2014-01-01

Background Somatostatin (SST) and some of its receptor subtypes have been implicated in pain signaling at the spinal level. In this study we have investigated the role of SST and its sst2A receptor (sst2A) in dorsal root ganglia (DRGs) and spinal cord. Results SST and sst2A protein and sst2 transcript were found in both mouse and human DRGs, sst2A-immunoreactive (IR) cell bodies and processes in lamina II in mouse and human spinal dorsal horn, and sst2A-IR nerve terminals in mouse skin. The receptor protein was associated with the cell membrane. Following peripheral nerve injury sst2A-like immunoreactivity (LI) was decreased, and SST-LI increased in DRGs. sst2A-LI accumulated on the proximal and, more strongly, on the distal side of a sciatic nerve ligation. Fluorescence-labeled SST administered to a hind paw was internalized and retrogradely transported, indicating that a SST-sst2A complex may represent a retrograde signal. Internalization of sst2A was seen in DRG neurons after systemic treatment with the sst2 agonist octreotide (Oct), and in dorsal horn and DRG neurons after intrathecal administration. Some DRG neurons co-expressed sst2A and the neuropeptide Y Y1 receptor on the cell membrane, and systemic Oct caused co-internalization, hypothetically a sign of receptor heterodimerization. Oct treatment attenuated the reduction of pain threshold in a neuropathic pain model, in parallel suppressing the activation of p38 MAPK in the DRGs Conclusions The findings highlight a significant and complex role of the SST system in pain signaling. The fact that the sst2A system is found also in human DRGs and spinal cord, suggests that sst2A may represent a potential pharmacologic target for treatment of neuropathic pain. PMID:24521084

Scrape off layer modelling studies for SST-I

NASA Astrophysics Data System (ADS)

Warrier, M.; Jaishankar, S.; Deshpande, S.; Coster, D.; Schneider, R.; Chaturvedi, S.; Srinivasan, R.; Braams, B. J.; SST Team

SOL modelling results for SST-1 (SST Team, Proceedings of the 16th IEEE/NPSS Symposium on Fusion Engineering, Champaign, IL, vol. II, 1995, p. 481) show a sheath limited flow regime. This is due to the low edge densities required by lower hybrid current drive (LHCD), coupled with high power input per unit volume. Coupled plasma-neutral transport studies using B2-Eirene [R. Schneider et al., J. Nucl. Mater. 196-198 (1992) 810] show significantly high charge exchange losses and radiated power from the core. It also shows that the heat flux to the inner divertor is higher than that to the outer divertor due to thinner inner SOL widths. The Monte-Carlo neutral transport code DEGAS [D. Heifitz et al., J. Comput. Phys. 46 (1982) 309] was used to optimise the baffle plate geometry and it was seen that a configuration where the baffle plate shields the main plasma from the divertor strike point results in reduced backflow of neutrals. The divertor erosion code DIVER (M. Warrier et al., SST Divertor Modelling Report, 1996-1997) was used to predict a steady state operating temperature for the SST divertor plate lying in the range 750-1000°C for which the erosion will be minimum.

A Comparison Between SST and AOT Derived from AVHRR and MODIS Data in the Frame of the CREPAD Program

NASA Astrophysics Data System (ADS)

Robles-Gonzalez, Cristina; Fernandez-Renau, Alix; Lopez Gordillo, Noelia; Sevilla, Angel Garcia; Suarez, Juana Santana

2010-12-01

Since 1997, the INTA-CREPAD (Centre for REception, Processing, Archiving and Dissemination of Earth Observation Data) program distributes freely some of the most demanded low-resolution remote sensing products: SST, Ocean Chl-a, NDVI, AOD... The data input for such products are captured at the Canary Space Station (Centro Espacial de Canarias, CEC). The data sensors received at the station and used in the CREPAD program are AVHRR, SEAWIFS and MODIS. In this study SST and AOD retrieved by CREPAD algorithms from AVHRR and the SEADAS derived SST and AOD from MODIS have compared. SST values agree very well within 0.1±0.5oC and the coefficient of correlation of the images is 0.9. AOD validation gives good results taking into account the differences in the algorithms used. Mean AOD difference at 0.630 μm is 0.01±0.05 and the correlation coefficient is 0.6.

No inter-gyre pathway for sea-surface temperature anomalies in the North Atlantic.

PubMed

Foukal, Nicholas P; Lozier, M Susan

2016-04-22

Recent Lagrangian analyses of surface drifters have questioned the existence of a surface current connecting the Gulf Stream (GS) to the subpolar gyre (SPG) and have cast doubt on the mechanism underlying an apparent pathway for sea-surface temperature (SST) anomalies between the two regions. Here we use modelled Lagrangian trajectories to determine the fate of surface GS water and satellite SST data to analyse pathways of GS SST anomalies. Our results show that only a small fraction of the surface GS water reaches the SPG, the water that does so mainly travels below the surface mixed layer, and GS SST anomalies do not propagate into the SPG on interannual timescales. Instead, the inter-gyre heat transport as part of the Atlantic Meridional Overturning Circulation must be accomplished via subsurface pathways. We conclude that the SST in the SPG cannot be predicted by tracking SST anomalies along the GS.

No inter-gyre pathway for sea-surface temperature anomalies in the North Atlantic

PubMed Central

Foukal, Nicholas P.; Lozier, M. Susan

2016-01-01

Recent Lagrangian analyses of surface drifters have questioned the existence of a surface current connecting the Gulf Stream (GS) to the subpolar gyre (SPG) and have cast doubt on the mechanism underlying an apparent pathway for sea-surface temperature (SST) anomalies between the two regions. Here we use modelled Lagrangian trajectories to determine the fate of surface GS water and satellite SST data to analyse pathways of GS SST anomalies. Our results show that only a small fraction of the surface GS water reaches the SPG, the water that does so mainly travels below the surface mixed layer, and GS SST anomalies do not propagate into the SPG on interannual timescales. Instead, the inter-gyre heat transport as part of the Atlantic Meridional Overturning Circulation must be accomplished via subsurface pathways. We conclude that the SST in the SPG cannot be predicted by tracking SST anomalies along the GS. PMID:27103496

ENSO/PDO-Like Variability of Tropical Ocean Surface Energy Fluxes Over the Satellite Era

NASA Technical Reports Server (NTRS)

Robertson, F. R.; Miller, Tim L.

2008-01-01

Recent variations of tropical climate on interannual to near-decadal scales have provided a useful target for studying the nature of climate feedback processes. A strong warm / cold ENSO couplet (e.g. 1997-2000) along with several subsequent weaker events are prominent interannual signals that are part of an apparent longer term strengthening of the Walker circulation during the mid to late 1990's with some weakening thereafter. Decadal scale changes in tropical SST structure during the 1990s are accompanied by focusing of precipitation over the Indo-Pacific warm pool and an increase in tropical ocean evaporation of order 1.0 % /decade. Associated with ENSO and PDO-like tropical SST changes are surface freshwater and radiative fluxes which have important implications for heat and energy transport variations. In this study we examine how surface fluxes attending interannual to decadal SST fluctuations, e.g. precipitation (GPCP, TRMM), turbulent fluxes (OAFlux), and radiative fluxes (ERBE/CERES, SRB) are coupled. Using these data we analyze vertically-integrated divergence of moist static energy, divMSE, and its dry static energy and latent energy components. We examine consistency between these data sets and explore relationships between SST variations, flux changes and modulation of tropical Walker and Hadley circulations. Strong signatures ofMSE flux transport linking ascending and descending regions of tropical circulations are found. Relative strengths of these fluxes and transports are interpreted as a measure of efficiency in the overall process of tropical heat balance during episodes of warm or cold tropical SST.

SST Technology Follow-On Program - Phase 2. Noise Suppressor/Nozzle Development. Volume 5. Advanced Suppressor Concepts and Full Scale Tests

DTIC Science & Technology

1975-03-01

Approved for U.S. Government only. This docu- ment is exempted from public availability be- cause of restrictions imposed by the Export Con- trol Act...Transmittal of this document outside the U.S. Government must have prior approval of the Supersonic Transport Office. 20 Security Classif (of this...linings may be determined by comparing nozzle/ejector radiated noise power levels between the unlined (hardwall) ejector case and the lined ejector

Disentangling sea-surface temperature and anthropogenic aerosol influences on recent trends in South Asian monsoon rainfall

NASA Astrophysics Data System (ADS)

Patil, Nitin; Venkataraman, Chandra; Muduchuru, Kaushik; Ghosh, Subimal; Mondal, Arpita

2018-05-01

Recent studies point to combined effects of changes in regional land-use, anthropogenic aerosol forcing and sea surface temperature (SST) gradient on declining trends in the South Asian monsoon (SAM). This study attempted disentangling the effects produced by changes in SST gradient from those by aerosol levels in an atmospheric general circulation model. Two pairs of transient ensemble simulations were made, for a 40-year period from 1971 to 2010, with evolving versus climatological SSTs and with anthropogenic aerosol emissions fixed at 1971 versus 2010, in each case with evolution of the other forcing element, as well as GHGs. Evolving SST was linked to a widespread feedback on increased surface temperature, reduced land-sea thermal contrast and a weakened Hadley circulation, with weakening of cross-equatorial transport of moisture transport towards South Asia. Increases in anthropogenic aerosol levels (1971 versus 2010), led to an intensification of drying in the peninsular Indian region, through several regional pathways. Aerosol forcing induced north-south asymmetries in temperature and sea-level pressure response, and a cyclonic circulation in the Bay of Bengal, leading to an easterly flow, which opposes the monsoon flow, suppressing moisture transport over peninsular India. Further, aerosol induced decreases in convection, vertically integrated moisture flux convergence, evaporation flux and cloud fraction, in the peninsular region, were spatially congruent with reduced convective and stratiform rainfall. Overall, evolution of SST acted through a weakening of cross-equatorial moisture flow, while increases in aerosol levels acted through suppression of Arabian Sea moisture transport, as well as, of convection and vertical moisture transport, to influence the suppression of SAM rainfall.

Interdecadal Change in SST Anomalies Associated with Winter Rainfall over South China

NASA Astrophysics Data System (ADS)

Liantong, Z.

2012-04-01

The present study investigates the interdecadal change in winter (January-February-March, or "JFM") rainfall over South China and in South China JFM rainfall-sea surface temperature (SST) relationship by using station observations for the period of 1958-2002, the Met Office Hadley Center's SST data for the period of 1900-2008, and the ERA-40 re-analysis for the period of 1958-2002. It is found that the relationship between South China JFM rainfall and SST experienced an obvious interdecadal change around the year 1978. The analyses show that the JFM rainfall anomalies during 1960-1977 and 1978-2002 were closely associated with the South China Sea (SCS) SST and El Niño-Southern Oscillation (ENSO), respectively. Moreover, southwesterly anomalies at 700 hPa dominate over the South China Sea for positive SCS SST anomaly years during 1960-1977, and for El Niño years during 1978-2002, respectively. These wind anomalies, which are associated with the enhancement of the western Pacific subtropical high, transport more moisture into South China, favoring increases in rainfall. KEY WORDS: ENSO; SCS SST; South China winter rainfall, western Pacific subtropical high.

Comparison of the Defense Meteorological Satellite Program (DMSP) and the NOAA Polar-Orbiting Operational Environmental Satellite (POES) Program,

DTIC Science & Technology

1985-10-01

grid points on 1 /20 lat /long meshI 4 c. SST global scale analysis ( 1 or 100 km lat /long grid) .. d. SST climatic scale analysis (50 or 500 km lat ...long grid) e. SST monthly means (2 1 /20 or 250 km lat /long grid) 3. Analog Sea Surface Temperature Product Set ’-%". V" " a. GOSSTCOMP charts - weekly...Mercator contour charts, each a ., 500 by 500 lat /long segment, 1 °C contour interval b. Regional charts - set of three charts covering the U.S

Contribution of tropical cyclones to abnormal sea surface temperature warming in the Yellow Sea in December 2004

NASA Astrophysics Data System (ADS)

Kim, Taekyun; Choo, Sung-Ho; Moon, Jae-Hong; Chang, Pil-Hun

2017-12-01

Unusual sea surface temperature (SST) warming occurred over the Yellow Sea (YS) in December 2004. To identify the causes of the abnormal SST warming, we conducted an analysis on atmospheric circulation anomalies induced by tropical cyclones (TCs) and their impacts on upper ocean characteristics using multiple datasets. With the analysis of various datasets, we explored a new aspect of the relationship between TC activity and SST. The results show that there is a significant link between TC activity over the Northwest Pacific (NWP) and SST in the YS. The integrated effect of consecutive TCs activity induces a large-scale atmospheric cyclonic circulation anomaly over the NWP and consequently anomalous easterly winds over the YS and East China Sea. The mechanism of the unusually warm SST in the YS can be explained by considering TCs acting as an important source of Ekman heat transport that results in substantial intrusion of relatively warm surface water into the YS interior. Furthermore, TC-related circulation anomalies contribute to the retention of the resulting warm SST anomalies in the entire YS.

Social Skills Interventions for Children with Asperger's Syndrome or High-Functioning Autism: A Review and Recommendations

ERIC Educational Resources Information Center

Rao, Patricia A.; Beidel, Deborah C.; Murray, Michael J.

2008-01-01

This paper reviews the literature examining social skills training (SST) programs for youth with AS/HFA, with an emphasis on critically evaluating efficacy and highlighting areas of future research. The review highlights the disparity between SST programs described in the extant literature, including lack of a universal definition of social…

An assessment of the effect of supersonic aircraft operations on the stratospheric ozone content

NASA Technical Reports Server (NTRS)

Poppoff, I. G.; Whitten, R. C.; Turco, R. P.; Capone, L. A.

1978-01-01

An assessment of the potential effect on stratospheric ozone of an advanced supersonic transport operations is presented. This assessment, which was undertaken because of NASA's desire for an up-to-date evaluation to guide programs for the development of supersonic technology and improved aircraft engine designs, uses the most recent chemical reaction rate data. From the results of the present assessment it would appear that realistic fleet sizes should not cause concern with regard to the depletion of the total ozone overburden. For example, the NOx emission of one type designed to cruise at 20 km altitude will cause the ozone overburden to increase by 0.03% to 0.12%, depending upon which vertical transport is used. These ozone changes can be compared with the predictions of a 1.74% ozone decrease (for 100 Large SST's flying at 20 km) made in 1974 by the FAA's Climatic Impact Assessment Program.

The Effect of Environmental Conditions on Tropical Deep Convective Systems Observed from the TRMM Satellite

NASA Technical Reports Server (NTRS)

Lin, Bing; Wielicki, Bruce A.; Minnis, Patrick; Chambers, Lin H.; Xu, Kuan-Man; Hu, Yongxiang; Fan, Tai-Fang

2005-01-01

This study uses measurements of radiation and cloud properties taken between January and August 1998 by three Tropical Rainfall Measuring Mission (TRMM) instruments, the Clouds and the Earth's Radiant Energy System (CERES) scanner, the TRMM Microwave Imager (TMI), and the Visible and InfraRed Scanner (VIRS), to evaluate the variations of tropical deep convective systems (DCS) with sea surface temperature (SST) and precipitation. This study finds that DCS precipitation efficiency increases with SST at a rate of approx. 2%/K. Despite increasing rainfall efficiency, the cloud areal coverage rises with SST at a rate of about 7%/K in the warm tropical seas. There, the boundary layer moisture supply for deep convection and the moisture transported to the upper troposphere for cirrus-anvil cloud formation increase by approx. 6.3%/K and approx. 4.0%/K, respectively. The changes in cloud formation efficiency, along with the increased transport of moisture available for cloud formation, likely contribute to the large rate of increasing DCS areal coverage. Although no direct observations are available, the increase of cloud formation efficiency with rising SST is deduced indirectly from measurements of changes in the ratio of DCS ice water path and boundary layer water vapor amount with SST. Besides the cloud areal coverage, DCS cluster effective sizes also increase with precipitation. Furthermore, other cloud properties, such as cloud total water and ice water paths, increase with SST. These changes in DCS properties will produce a negative radiative feedback for the earth's climate system due to strong reflection of shortwave radiation by the DCS. These results significantly differ from some previous hypothesized dehydration scenarios for warmer climates, and have great potential in testing current cloud-system resolving models and convective parameterizations of general circulation models.

Multi-species coral Sr/Ca-based sea-surface temperature reconstruction using Orbicella faveolata and Siderastrea siderea from the Florida Straits

USGS Publications Warehouse

Flannery, Jennifer A.; Richey, Julie N.; Thirumalai, Kaustubh; Poore, Richard Z.; DeLong, Kristine L.

2017-01-01

We present new, monthly-resolved Sr/Ca-based sea-surface temperature (SST) records from two species of massive coral, Orbicella faveolata and Siderastrea siderea, from the Dry Tortugas National Park, FL, USA (DTNP). We combine these new records with published data from three additional S. siderea coral colonies to generate a 278-year long multi-species stacked Sr/Ca-SST record from DTNP. The composite record of mean annual Sr/Ca-SST at DTNP shows pronounced decadal-scale variability with a range of 1 to 2°C. Notable cool intervals in the Sr/Ca-derived SST lasting about a decade centered at ~1845, ~1935, and ~1965 are associated with reduced summer Sr/Ca-SST (monthly maxima < 29°C), and imply a reduction in the spatial extent of the Atlantic Warm Pool (AWP). There is significant coherence between the composite DTNP Sr/Ca-SST record and the Atlantic Multidecadal Oscillation (AMO) index, with the AMO lagging Sr/Ca-SST at DTNP by 9 years. Low frequency variability in the Gulf Stream surface transport, which originates near DTNP, may provide a link for the lagged relationship between multidecadal variability at DTNP and the AMO.

Simulation Based Training Improves Airway Management for Helicopter EMS Teams

NASA Technical Reports Server (NTRS)

Dhindsa, Harinder S.; Reid, Renee; Murray, David; Lovelady, James; Powell, Katie; Sayles, Jeff; Stevenson, Christopher; Baker, Kathy; Solada, Brian; Carroll, Scott;

Recalibration of the Shear Stress Transport Model to Improve Calculation of Shock Separated Flows

NASA Technical Reports Server (NTRS)

Georgiadis, Nicholas J.; Yoder, Dennis A.

2013-01-01

The Menter Shear Stress Transport (SST) k . turbulence model is one of the most widely used two-equation Reynolds-averaged Navier-Stokes turbulence models for aerodynamic analyses. The model extends Menter s baseline (BSL) model to include a limiter that prevents the calculated turbulent shear stress from exceeding a prescribed fraction of the turbulent kinetic energy via a proportionality constant, a1, set to 0.31. Compared to other turbulence models, the SST model yields superior predictions of mild adverse pressure gradient flows including those with small separations. In shock - boundary layer interaction regions, the SST model produces separations that are too large while the BSL model is on the other extreme, predicting separations that are too small. In this paper, changing a1 to a value near 0.355 is shown to significantly improve predictions of shock separated flows. Several cases are examined computationally and experimental data is also considered to justify raising the value of a1 used for shock separated flows.

Asteroid Detection Results Using the Space Surveillance Telescope

NASA Astrophysics Data System (ADS)

Ruprecht, Jessica D.; Ushomirsky, Gregory; Woods, Deborah F.; Viggh, Herbert E. M.; Varey, Jacob; Cornell, Mark E.; Stokes, Grant

2015-11-01

From 1998-2013, MIT Lincoln Laboratory operated a highly successful near-Earth asteroid search program using two 1-m optical telescopes located at the MIT Lincoln Laboratory Experimental Test Site (ETS) in Socorro, N.M. In 2014, the Lincoln Near-Earth Asteroid Research (LINEAR) program successfully transitioned operations from the two 1-m telescopes to the 3.5-m Space Surveillance Telescope (SST) located at Atom Site on White Sands Missile Range, N.M. This paper provides a summary of first-year performance and results for the LINEAR program with SST and provides an update on recent improvements to the moving-object pipeline architecture that increase utility of SST data for NEO discovery and improve sensitivity to fast-moving objects. Ruprecht et al. (2014) made predictions for SST NEO search productivity as a function of population model. This paper assesses the NEO search performance of SST in the first 1.5 years of operation and compares results to model predictions.This work is sponsored by the Defense Advanced Research Projects Agency and the National Aeronautics and Space Administration under Air Force Contract #FA8721-05-C-0002. The views, opinions, and/or findings contained in this article/presentation are those of the authors / presenters and should not be interpreted as representing the official views or policies of the Department of Defense or the U.S. Government. Distribution Statement A: Approved for public release, distribution unlimited.

Asteroid Detection Results Using the Space Surveillance Telescope

NASA Astrophysics Data System (ADS)

Ruprecht, J.; Ushomirsky, G.; Woods, D.; Viggh, H.; Varey, J.; Cornell, M.; Stokes, G.

From 1998-2013, MIT Lincoln Laboratory operated a highly successful near-Earth asteroid search program using two 1-m optical telescopes located at the MIT Lincoln Laboratory Experimental Test Site (ETS) in Socorro, N.M. In 2014, the Lincoln Near-Earth Asteroid Research (LINEAR) program successfully transitioned operations from the two 1-m telescopes to the 3.5-m Space Surveillance Telescope (SST) located at Atom Site on White Sands Missile Range, N.M. This paper provides a summary of first-year performance and results for the LINEAR program with SST and provides an update on recent improvements to the moving-object pipeline architecture that increase utility of SST data for NEO discovery and improve sensitivity to fast-moving objects. Ruprecht et al. (2014) made predictions for SST NEO search productivity as a function of population model. This paper assesses the NEO search performance of SST in the first 1.5 years of operation and compares results to model predictions. This work is sponsored by the Defense Advanced Research Projects Agency and the National Aeronautics and Space Administration under Air Force Contract #FA8721-05-C-0002. The views, opinions, and/or findings contained in this article/presentation are those of the authors / presenters and should not be interpreted as representing the official views or policies of the Department of Defense or the U.S. Government. Distribution Statement A: Approved for public release, distribution unlimited.

High Altitude Radiations Relevant to the High Speed Civil Transport (HSCT)

NASA Technical Reports Server (NTRS)

Wilson, J. W.; Goldhagan, P.; Maiden, D. L.; Tai, H.

2004-01-01

The Langley Research Center (LaRC) performed atmospheric radiation studies under the SST development program in which important ionizing radiation components were measured and extended by calculations to develop the existing atmospheric ionizing radiation (AIR) model. In that program the measured neutron spectrum was limited to less than 10 MeV by the available 1960-1970 instrumentation. Extension of the neutron spectrum to high energies was made using the LaRC PROPER-3C monte carlo code. It was found that the atmospheric neutrons contributed about half of the dose equivalent and approximately half of the neutron contribution was from high energy neutrons above 10 MeV. Furthermore, monte carlo calculations of solar particle events showed that potential exposures as large as 10-100 mSv/hr may occur on important high latitude routes but acceptable levels of exposure could be obtained if timely descent to subsonic altitudes could be made. The principal concern was for pregnant occupants onboard the aircraft. As a result of these studies the FAA Advisory Committee on the Radiobiological Aspects of the SST recommended: 1. Crew members will have to be informed of their exposure levels 2. Maximum exposures on any flight to be limited to 5 mSv 3. Airborne radiation detection devices for total exposure and exposure rates 4. Satellite monitoring system to provide SST aircraft real-time information on atmospheric radiation levels for exposure mitigation 5. A solar forecasting system to warn flight operations of an impending solar event for flight scheduling and alert status. These recommendations are a reasonable starting point to requirements for the HSCT with some modification reflecting new standards of protection as a result of changing risk coefficients.

Measured and Calculated Neutron Spectra and Dose Equivalent Rates at High Altitudes; Relevance to SST Operations and Space Research

NASA Technical Reports Server (NTRS)

Foelsche, T.; Mendell, R. B.; Wilson, J. W.; Adams, R. R.

1974-01-01

Results of the NASA Langley-New York University high-altitude radiation study are presented. Measurements of the absorbed dose rate and of secondary fast neutrons (1 to 10 MeV energy) during the years 1965 to 1971 are used to determine the maximum radiation exposure from galactic and solar cosmic rays of supersonic transport (SST) and subsonic jet occupants. The maximum dose equivalent rates that the SST crews might receive turn out to be 13 to 20 percent of the maximum permissible dose rate (MPD) for radiation workers (5 rem/yr). The exposure of passengers encountering an intense giant-energy solar particle event could exceed the MPD for the general population (0.5 rem/yr), but would be within these permissible limits if in such rare cases the transport descends to subsonic altitude; it is in general less than 12 percent of the MPD. By Monte Carlo calculations of the transport and buildup of nucleons in air for incident proton energies E of 0.02 to 10 GeV, the measured neutron spectra were extrapolated to lower and higher energies and for galactic cosmic rays were found to continue with a relatively high intensity to energies greater than 400 MeV, in a wide altitude range. This condition, together with the measured intensity profiles of fast neutrons, revealed that the biologically important fast and energetic neutrons penetrate deep into the atmosphere and contribute approximately 50 percent of the dose equivalant rates at SST and present subsonic jet altitudes.

Sensitivity of the atmospheric water cycle to corrections of the sea surface temperature bias over southern Africa in a regional climate model

NASA Astrophysics Data System (ADS)

Weber, Torsten; Haensler, Andreas; Jacob, Daniela

2017-12-01

Regional climate models (RCMs) have been used to dynamically downscale global climate projections at high spatial and temporal resolution in order to analyse the atmospheric water cycle. In southern Africa, precipitation pattern were strongly affected by the moisture transport from the southeast Atlantic and southwest Indian Ocean and, consequently, by their sea surface temperatures (SSTs). However, global ocean models often have deficiencies in resolving regional to local scale ocean currents, e.g. in ocean areas offshore the South African continent. By downscaling global climate projections using RCMs, the biased SSTs from the global forcing data were introduced to the RCMs and affected the results of regional climate projections. In this work, the impact of the SST bias correction on precipitation, evaporation and moisture transport were analysed over southern Africa. For this analysis, several experiments were conducted with the regional climate model REMO using corrected and uncorrected SSTs. In these experiments, a global MPI-ESM-LR historical simulation was downscaled with the regional climate model REMO to a high spatial resolution of 50 × 50 km2 and of 25 × 25 km2 for southern Africa using a double-nesting method. The results showed a distinct impact of the corrected SST on the moisture transport, the meridional vertical circulation and on the precipitation pattern in southern Africa. Furthermore, it was found that the experiment with the corrected SST led to a reduction of the wet bias over southern Africa and to a better agreement with observations as without SST bias corrections.

Sensitivity of Coupled Tropical Pacific Model Biases to Convective Parameterization in CESM1

NASA Astrophysics Data System (ADS)

Woelfle, M. D.; Yu, S.; Bretherton, C. S.; Pritchard, M. S.

2018-01-01

Six month coupled hindcasts show the central equatorial Pacific cold tongue bias development in a GCM to be sensitive to the atmospheric convective parameterization employed. Simulations using the standard configuration of the Community Earth System Model version 1 (CESM1) develop a cold bias in equatorial Pacific sea surface temperatures (SSTs) within the first two months of integration due to anomalous ocean advection driven by overly strong easterly surface wind stress along the equator. Disabling the deep convection parameterization enhances the zonal pressure gradient leading to stronger zonal wind stress and a stronger equatorial SST bias, highlighting the role of pressure gradients in determining the strength of the cold bias. Superparameterized hindcasts show reduced SST bias in the cold tongue region due to a reduction in surface easterlies despite simulating an excessively strong low-level jet at 1-1.5 km elevation. This reflects inadequate vertical mixing of zonal momentum from the absence of convective momentum transport in the superparameterized model. Standard CESM1simulations modified to omit shallow convective momentum transport reproduce the superparameterized low-level wind bias and associated equatorial SST pattern. Further superparameterized simulations using a three-dimensional cloud resolving model capable of producing realistic momentum transport simulate a cold tongue similar to the default CESM1. These findings imply convective momentum fluxes may be an underappreciated mechanism for controlling the strength of the equatorial cold tongue. Despite the sensitivity of equatorial SST to these changes in convective parameterization, the east Pacific double-Intertropical Convergence Zone rainfall bias persists in all simulations presented in this study.

Middle Pliocene sea surface temperature variability

USGS Publications Warehouse

Dowsett, H.J.; Chandler, M.A.; Cronin, T. M.; Dwyer, Gary S.

2005-01-01

Estimates of sea surface temperature (SST) based upon foraminifer, diatom, and ostracod assemblages from ocean cores reveal a warm phase of the Pliocene between about 3.3 and 3.0 Ma. Pollen records and plant megafossils, although not as well dated, show evidence for a warmer climate at about the same time. Increased greenhouse forcing and altered ocean heat transport are the leading candidates for the underlying cause of Pliocene global warmth. Despite being a period of global warmth, this interval encompasses considerable variability. Two new SST reconstructions are presented that are designed to provide a climatological error bar for warm peak phases of the Pliocene and to document the spatial distribution and magnitude of SST variability within the mid-Pliocene warm period. These data suggest long-term stability of low-latitude SST and document greater variability in regions of maximum warming. Copyright 2005 by the American Geophysical Union.

North Pacific Decadal Variability in the GEOS-5 Atmosphere-Ocean Model

NASA Technical Reports Server (NTRS)

Achuthavarier, Deepthi; Schubert, Siegfried D.; Vikhliaev, Yury V.

2013-01-01

This study examines the mechanisms of the Pacific decadal oscillation (PDO) in the GEOS-5 general circulation model. The model simulates a realistic PDO pattern that is resolved as the first empirical orthogonal function (EOF) of winter sea surface temperature (SST). The simulated PDO is primarily forced by Aleutian low through Ekman transport and surface fluxes, and shows a red spectrum without any preferred periodicity. This differs from the observations, which indicate a greater role of El Nino-Southern Oscillation (ENSO) forcing, and likely reflects the too short time scale of the simulated ENSO. The geostrophic transport in response to the Aleutian low is limited to the Kuroshio-Oyashio Extension, and is unlikely the main controlling factor in this model, although it reinforces the Ekman-induced SST anomalies. The delay between the Aleutian low and the PDO is relatively short (1 year) suggesting that the fast Ekman response (rather than Rossby wave propagation) sets the SST pattern immediately following an Aleutian low fluctuation. The atmospheric feedback (response to the SST) is only about 25 of the forcing and never evolves into an Aleutian low completely, instead projecting onto the North Pacific Oscillation (NPO), a meridional dipole in sea level pressure (SLP). The lack of preferred periodicity and weak atmospheric response bothindicate a coupled oscillation is an unlikely mechanism for the PDO in this model. In agreement with recent studies, the NPO is correlated with the North Pacific Gyre Oscillation (NPGO), which is another leading EOF of the North Pacific SST. A possible connection between the PDO and the NPGO is discussed.

Advanced supersonic technology and its implications for the future

NASA Technical Reports Server (NTRS)

Driver, C.

1979-01-01

A brief overview of the NASA Supersonic Cruise Research (SCR) program is presented. The SCR program has identified significant improvements in the areas of aerodynamics, structures, propulsion, noise reduction, takeoff and landing procedures, and advanced configuration concepts. These improvements tend to overcome most of the problems which led to the cancellation of the National SST program. They offer the promise of an advanced SST family of aircraft which are environmentally acceptable, have flexible range-payload capability, and are economically viable. The areas of technology addressed by the SCR program have direct application to advanced military aircraft and to supersonic executive aircraft.

Long-terms Change of Sea Surface Temperature in the South China Sea

NASA Astrophysics Data System (ADS)

Park, Y. G.; Choi, A.

2016-02-01

Using the Hadley Centre Global Sea Ice and Sea Surface Temperature (HadISST) the long term trend in the South China Sea (SCS) sea surface temperature (SST) between 1950 and 2008 is investigated. Both in winter and summer SST was increased by comparable amounts, but the warming patterns and the governing processes was different. During winter warming rate was greater in the deep basin in the central part, while during summer near the southern part. In winter the net heat flux into the sea was increased and could contribute to the warming. The pattern of the heat flux, however, was different from that of the warming. The heat flux was increased over the coastal area where warming was weaker, but decreased in deeper part where warming was stronger. The northeasterly monsoon wind weakened to lower the shoreward Ekman transport and the sea surface height gradient. The cyclonic gyre that transports cold northern water to south was weakened to warm the ocean. The effect manifested more strongly southward western boundary currents, and subsequently cold advection. In summer the net surface heat flux, however, was reduced and could not contribute to the warming. Over the southern part of the ocean the weakening of the southwesterly summer monsoon reduced southeastward Ekman transport, which is antiparallel to the mean SST gradient. Firstly, southeastward cold advection is reduced to warm the surface near the southeastern boundary of the SCS. The upwelling southeast of Vietnam was also weakened to raise the SST east of Vietnam. Thus the weakening of the wind in each season was the ultimate cause of the warming, but the responses of the ocean that lead to the warming were different.

The ASTRI SST-2M prototype for the Cherenkov Telescope Array: prototype technologies goals and strategies for the future SST

NASA Astrophysics Data System (ADS)

Marchiori, Gianpietro; Busatta, Andrea; Giacomel, Stefano; Folla, Ivan; Valsecchi, Marco; Canestrari, Rodolfo; Bonnoli, Giacomo; Cascone, Enrico; Conconi, Paolo; Fiorini, Mauro; Giro, Enrico; La Palombara, Nicola; Pareschi, Giovanni; Perri, Luca; Rodeghiero, Gabriele; Sironi, Giorgia; Stringhetti, Luca; Toso, Giorgio; Tosti, Gino; Pellicciari, Carlo

2014-07-01

The Cherenkov Telescope Array (CTA) observatory will represent the next generation of Imaging Atmospheric Cherenkov Telescope. Using a combination of large-, medium-, and small-scale telescopes (LST, MST, SST, respectively), it will explore the Very High Energy domain from a few tens of GeVup to about few hundreds of TeV with unprecedented sensitivity, angular resolution and imaging quality. In this framework, the Italian ASTRI program, led by the Italian National Institute of Astrophysics (INAF) developed a 4-meter class telescope, which will adopt an aplanatic, wide-field, double-reflection optical layout in a Schwarzschild- Couder configuration. Within this program INAF assigned to the consortium between Galbiati Group and EIE Group the construction, assembly and tests activities of the prototype named ASTRI SST-2M. On the basis of the lesson learnt from the prototype, other telescopes will be produced, starting from a re-design phase, in order to optimize performances and the overall costs and production schedule for the CTA-SST telescope. This paper will firstly give an overview of the concept for the SST prototype mount structure. In this contest, the technologies adopted for the design, manufacturing and tests of the entire system will be presented. Moreover, a specific focus on the challenges of the prototype and the strategies associated with it will be provided, in order to outline the near future performance goals for this type of Cherenkov telescopes employed for Gamma ray science.

Investigation of laminar to turbulent transition phenomena effects on impingement heat transfer

NASA Astrophysics Data System (ADS)

Isman, Mustafa Kemal; Morris, Philip J.; Can, Muhiddin

2016-10-01

Turbulent impinging air flow is investigated numerically by using the ANSYS-CFX® code. All computations are performed by considering three-dimensional, steady, and incompressible flow. Three different Reynolds averaged Navier-Stokes (RANS) turbulence models and two Reynolds stress models (RSM's) are employed. Furthermore three different laminar to turbulent transition (LTT) models are employed with the shear stress transport (SST) and the baseline (BSL) models. Results show that predictions of the SST and two RSM's are very close each other and these models' results are in better agreement with the experimental data when all Reynolds numbers used in this study are considered. Secondary maxima in Nusselt number can be seen only if the LTT formula is employed with SST and BSL models.

SST algorithms in ACSPO reanalysis of AVHRR GAC data from 2002-2013

NASA Astrophysics Data System (ADS)

Petrenko, B.; Ignatov, A.; Kihai, Y.; Zhou, X.; Stroup, J.

2014-05-01

In response to a request from the NOAA Coral Reef Watch Program, NOAA SST Team initiated reprocessing of 4 km resolution GAC data from AVHRRs flown onboard NOAA and MetOp satellites. The objective is to create a longterm Level 2 Advanced Clear-Sky Processor for Oceans (ACSPO) SST product, consistent with NOAA operations. ACSPO-Reanalysis (RAN) is used as input in the NOAA geo-polar blended Level 4 SST and potentially other Level 4 SST products. In the first stage of reprocessing (reanalysis 1, or RAN1), data from NOAA-15, -16, -17, -18, -19, and Metop-A and -B, from 2002-present have been processed with ACSPO v2.20, and matched up with quality controlled in situ data from in situ Quality Monitor (iQuam) version 1. The ~12 years time series of matchups were used to develop and explore the SST retrieval algorithms, with emphasis on minimizing spatial biases in retrieved SSTs, close reproduction of the magnitudes of true SST variations, and maximizing temporal, spatial and inter-platform stability of retrieval metrics. Two types of SST algorithms were considered: conventional SST regressions, and recently developed incremental regressions. The conventional equations were adopted in the EUMETSAT OSI-SAF formulation, which, according to our previous analyses, provide relatively small regional biases and well-balanced combination of precision and sensitivity, in its class. Incremental regression equations were specifically elaborated to automatically correct for model minus observation biases, always present when RTM simulations are employed. Improved temporal stability was achieved by recalculation of SST coefficients from matchups on a daily basis, with a +/-45 day window around the current date. This presentation describes the candidate SST algorithms considered for the next round of ACSPO reanalysis, RAN2.

A Tropical View of Atlantic Multidecadal SST Variability over the Last Two Millennia

NASA Astrophysics Data System (ADS)

Wurtzel, J. B.; Black, D. E.; Thunell, R.; Peterson, L. C.; Tappa, E. J.; Rahman, S.

2011-12-01

Instrumental and proxy-reconstructions show the existence of a 60-80 year periodicity in Atlantic sea surface temperature (SST), known as the Atlantic Multidecadal Oscillation (AMO). The AMO is correlated with circum-tropical Atlantic climate phenomena such as Sahel and Nordeste rainfall, as well as Atlantic hurricane patterns. Though it has been suggested that the AMO is controlled by thermohaline circulation, much debate exists as to whether the SST fluctuations are a result of anthropogenic forcing or natural climate variability. Our ability to address this issue has been limited by instrumental SST records that rarely extend back more than 50-100 years and proxy reconstructions that are largely terrestrial-based. Here we present a high-resolution marine sediment-derived reconstruction of seasonal tropical Atlantic SSTs from the Cariaco Basin spanning the past two millennia that is correlated with instrumental SSTs and the AMO for the period of overlap. The full record demonstrates that seasonality is largely controlled by variations in winter/spring SST. Wavelet analysis of the proxy data suggest that variability in the 60-80 year band evolved 250 years ago, while 40-60 year periodicities dominate earlier parts of the record. At least over the last millennia, multidecadal- and centennial- scale SST variability in the tropical Atlantic appears related to Atlantic meridional overturning circulation (AMOC) fluctuations and its associated northward heat transport that in turn may be driven by solar variability. An inverse correlation between the tropical proxy annual average SST record and Δ14C indicates that the tropics experienced positive SST anomalies during times of reduced solar activity, possibly as a result of decreased AMOC strength (Figure 1).

Numerical flow simulation and efficiency prediction for axial turbines by advanced turbulence models

NASA Astrophysics Data System (ADS)

Jošt, D.; Škerlavaj, A.; Lipej, A.

2012-11-01

Numerical prediction of an efficiency of a 6-blade Kaplan turbine is presented. At first, the results of steady state analysis performed by different turbulence models for different operating regimes are compared to the measurements. For small and optimal angles of runner blades the efficiency was quite accurately predicted, but for maximal blade angle the discrepancy between calculated and measured values was quite large. By transient analysis, especially when the Scale Adaptive Simulation Shear Stress Transport (SAS SST) model with zonal Large Eddy Simulation (ZLES) in the draft tube was used, the efficiency was significantly improved. The improvement was at all operating points, but it was the largest for maximal discharge. The reason was better flow simulation in the draft tube. Details about turbulent structure in the draft tube obtained by SST, SAS SST and SAS SST with ZLES are illustrated in order to explain the reasons for differences in flow energy losses obtained by different turbulence models.

A reconstruction of sea surface temperature variability in the southeastern Gulf of Mexico from 1734 to 2008 C.E. using cross-dated Sr/Ca records from the coral Siderastrea siderea

NASA Astrophysics Data System (ADS)

DeLong, Kristine L.; Flannery, Jennifer A.; Poore, Richard Z.; Quinn, Terrence M.; Maupin, Christopher R.; Lin, Ke; Shen, Chuan-Chou

2014-05-01

This study uses skeletal variations in coral Sr/Ca from three Siderastrea siderea coral colonies within the Dry Tortugas National Park in the southeastern Gulf of Mexico (24°42'N, 82°48'W) to reconstruct monthly sea surface temperature (SST) variations from 1734 to 2008 Common Era (C.E.). Calibration and verification of the replicated coral Sr/Ca-SST reconstruction with local, regional, and historical temperature records reveals that this proxy-temperature relationship is stable back to 1879 C.E. The coral SST reconstruction contains robust interannual ( 2.0°C) and multidecadal variability ( 1.5°C) for the past 274 years, the latter of which does not covary with the Atlantic Multidecadal Oscillation. Winter SST extremes are more variable than summer SST extremes (±2.2°C versus ±1.6°C, 2σ) suggesting that Loop Current transport in the winter dominates variability on interannual and longer time scales. Summer SST maxima are increasing (+1.0°C for 274 years, σMC = ±0.5°C, 2σ), whereas winter SST minima contain no significant trend. Colder decades ( 1.5°C) during the Little Ice Age (LIA) do not coincide with decades of sunspot minima. The coral SST reconstruction contains similar variability to temperature reconstructions from the northern Gulf of Mexico (planktic foraminifer Mg/Ca) and the Caribbean Sea (coral Sr/Ca) suggesting areal reductions in the Western Hemisphere Warm Pool during the LIA. Mean summer coral SST extremes post-1985 C.E. (29.9°C) exceeds the long-term summer average (29.2°C for 1734-2008 C.E.), yet the warming trend after 1985 C.E. (0.04°C for 24 years, σMC = ±0.5, 2σ) is not significant, whereas Caribbean coral Sr/Ca studies contain a warming trend for this interval.

Impact of Variable SST on Simulated Warm Season Precipitation

NASA Astrophysics Data System (ADS)

Saleeby, S. M.; Cotton, W. R.

2007-05-01

The Colorado State University - Regional Atmospheric Modeling System (CSU-RAMS) is being used to examine the variability in monsoon-related warm season precipitation over Mexico and the United States due to variability in SST. Given recent improvements and increased resolution in satellite derived SSTs it is pertinent to examine the sensitivity of the RAMS model to the variety of SST data sources that are available. In particular, we are examining this dependence across continental scales over the full warm season, as well as across the regional scale centered around the Gulf of California on time scales of individual surge events. In this study we performed an ensemble of simulations that include the 2002, 2003, and 2004 warm seasons with use of the Climatology, Reynold's, AVHRR, and MODIS SSTs. From the seasonal 90-day simulations with 30km grid spacing, it was found that variations in surface latent heat flux are directly linked to differences in SST. Regions with cooler (warmer) SST have decreased (increased) moisture flux from the ocean which is in proportion to the magnitude of the SST difference. Over the eastern Pacific, differences in low-level horizontal moisture flux show a general trend toward reduced fluxes over cooler waters and very little inland impact. Over the Gulf of Mexico, however, there is substantial variability for each dataset comparison, despite having only limited variability among the SST data. Causes of this unexpected variability are not straight-forward. Precipitation impacts are greatest near the southern coast of Mexico and along the Sierra Madres. Precipitation variability over the CONUS is rather chaotic and is limited to areas impacted by the Gulf of Mexico or monsoon convection. Another unexpected outcome is the lack of variability in areas near the northern Gulf of California where SST and latent heat flux variability is a maximum. From the 7-day surge period simulations at 7km grid spacing, we found that SST differences on the higher resolution nested grid reveal fine scale variability that is otherwise smoothed out or unapparent on the coarser grid. Unlike the coarse grid, the latent heat flux, temperature, and moisture transport differences on the fine grid reveal an inland impact. This is likely due to fine scale variability in onshore moisture transport and sea- breeze circulations which may alter monsoonal convection and precipitation. However, only the largest SST differences (spatially and in magnitude) tend to invoke large, coherent responses in moisture flux. The SST variability at high resolution produces relatively large differences in precipitation that are focused along the slopes of the SMO, with a tendency toward greater variability along the western slope adjacent to the coast. The precipitation differences are of fine resolution, with variability of +/- 30 mm (over 5 days) along the length of the SMO. Variability on the fine grid also invokes precipitation changes over AZ/NM that are not resolved on the coarse grid. Vertical cross-sections examined along the GoC during the surge episode revealed variations in the moisture and temperature structure of the surge. The cooler SSTs in the climatological dataset produced the greatest variability compared to the other datasets. The surge produced from climatology SSTs was nearly 5g/kg drier and up to 4°C cooler compared to surges influenced by the SST datasets. The overall northward propagation of the surge appeared unaffected by the SSTs.

Sensitivity of Pacific Cold Tongue and Double-ITCZ Bias to Convective Parameterization

NASA Astrophysics Data System (ADS)

Woelfle, M.; Bretherton, C. S.; Pritchard, M. S.; Yu, S.

2016-12-01

Many global climate models struggle to accurately simulate annual mean precipitation and sea surface temperature (SST) fields in the tropical Pacific basin. Precipitation biases are dominated by the double intertropical convergence zone (ITCZ) bias where models exhibit precipitation maxima straddling the equator while only a single Northern Hemispheric maximum exists in observations. The major SST bias is the enhancement of the equatorial cold tongue. A series of coupled model simulations are used to investigate the sensitivity of the bias development to convective parameterization. Model components are initialized independently prior to coupling to allow analysis of the transient response of the system directly following coupling. These experiments show precipitation and SST patterns to be highly sensitive to convective parameterization. Simulations in which the deep convective parameterization is disabled forcing all convection to be resolved by the shallow convection parameterization showed a degradation in both the cold tongue and double-ITCZ biases as precipitation becomes focused into off-equatorial regions of local SST maxima. Simulations using superparameterization in place of traditional cloud parameterizations showed a reduced cold tongue bias at the expense of additional precipitation biases. The equatorial SST responses to changes in convective parameterization are driven by changes in near equatorial zonal wind stress. The sensitivity of convection to SST is important in determining the precipitation and wind stress fields. However, differences in convective momentum transport also play a role. While no significant improvement is seen in these simulations of the double-ITCZ, the system's sensitivity to these changes reaffirm that improved convective parameterizations may provide an avenue for improving simulations of tropical Pacific precipitation and SST.

Interannual to Decadal SST Variability in the Tropical Indian Ocean

NASA Astrophysics Data System (ADS)

Wang, G.; Newman, M.; Han, W.

2017-12-01

The Indian Ocean has received increasing attention in recent years for its large impacts on regional and global climate. However, due mainly to the close interdependence of the climate variation within the Tropical Pacific and the Indian Ocean, the internal sea surface temperature (SST) variability within the Indian Ocean has not been studied extensively on longer time scales. In this presentation we will show analysis of the interannual to decadal SST variability in the Tropical Indian Ocean in observations and Linear Inverse Model (LIM) results. We also compare the decoupled Indian Ocean SST variability from the Pacific against fully coupled one based on LIM integrations, to test the factors influence the features of the leading SST modes in the Indian Ocean. The result shows the Indian Ocean Basin (IOB) mode, which is strongly related to global averaged SST variability, passively responses to the Pacific variation. Without tropical Indo-Pacific coupling interaction, the intensity of IOB significantly decreases by 80%. The Indian Ocean Dipole (IOD) mode demonstrates its independence from the Pacific SST variability since the IOD does not change its long-term characteristics at all without inter-basin interactions. The overall SSTA variance decreases significantly in the Tropical Indian Ocean in the coupling restricted LIM runs, especially when the one-way impact from the Pacific to the Indian Ocean is turned off, suggesting that most of the variability in the Indian Ocean comes from the Pacific influence. On the other hand, the Indian Ocean could also transport anomalies to the Pacific, making the interaction a complete two-way process.

NASA Centers and Universities Collaborate Through Smallsat Technology Partnerships

NASA Technical Reports Server (NTRS)

Cockrell, James

2018-01-01

The Small Spacecraft Technology (SST) Program within the NASA Space Technology Mission Directorate is chartered develop and demonstrate the capabilities that enable small spacecraft to achieve science and exploration missions in "unique" and "more affordable" ways. Specifically, the SST program seeks to enable new mission architectures through the use of small spacecraft, to expand the reach of small spacecraft to new destinations, and to make possible the augmentation existing assets and future missions with supporting small spacecraft. The SST program sponsors smallsat technology development partnerships between universities and NASA Centers in order to engage the unique talents and fresh perspectives of the university community and to share NASA experience and expertise in relevant university projects to develop new technologies and capabilities for small spacecraft. These partnerships also engage NASA personnel in the rapid, agile and cost-conscious small spacecraft approaches that have evolved in the university community, as well as increase support to university efforts and foster a new generation of innovators for NASA and the nation.

Idealized modeling of convective organization with changing sea surface temperatures using multiple equilibria in weak temperature gradient simulations

NASA Astrophysics Data System (ADS)

Sentić, Stipo; Sessions, Sharon L.

2017-06-01

The weak temperature gradient (WTG) approximation is a method of parameterizing the influences of the large scale on local convection in limited domain simulations. WTG simulations exhibit multiple equilibria in precipitation; depending on the initial moisture content, simulations can precipitate or remain dry for otherwise identical boundary conditions. We use a hypothesized analogy between multiple equilibria in precipitation in WTG simulations, and dry and moist regions of organized convection to study tropical convective organization. We find that the range of wind speeds that support multiple equilibria depends on sea surface temperature (SST). Compared to the present SST, low SSTs support a narrower range of multiple equilibria at higher wind speeds. In contrast, high SSTs exhibit a narrower range of multiple equilibria at low wind speeds. This suggests that at high SSTs, organized convection might occur with lower surface forcing. To characterize convection at different SSTs, we analyze the change in relationships between precipitation rate, atmospheric stability, moisture content, and the large-scale transport of moist entropy and moisture with increasing SSTs. We find an increase in large-scale export of moisture and moist entropy from dry simulations with increasing SST, which is consistent with a strengthening of the up-gradient transport of moisture from dry regions to moist regions in organized convection. Furthermore, the changes in diagnostic relationships with SST are consistent with more intense convection in precipitating regions of organized convection for higher SSTs.

Creating a Teacher-Student Research Program Using the Spitzer Space Telescope

NASA Astrophysics Data System (ADS)

Daou, D.; Pompea, S.; Thaller, M.

2004-12-01

The Spitzer Science Center (SSC) and the National Optical Astronomy Observatory (NOAO) have created a program for teacher and student research using observing time on the Spitzer Space Telescope. The participating teachers attended a fall, 2004 workshop to become familiar with the Spitzer Space Telescope (SST) archives, and to receive training in infrared astronomy and observational techniques. The teachers will also attend a workshop offered by the SSC to learn about the observation planning process, and telescope and instrument capabilities. This program has as its goals the fundamental NASA goals of inspiring and motivating students to pursue careers in science, technology, engineering, and mathematics as well as to engage the public in shaping and sharing the experience of exploration and discovery. Our educational plan addresses the NASA objectives of improving student proficiency in science and improving science instruction by providing a unique opportunity to a group of teachers and students to observe with the SST and work with the SST archival data. This program allows a team of 12 teachers and their students to utilize up to 3 hours of Director's discretionary observing time on the Spitzer Space Telescope for educational observations. Leveraging on a well-established teacher professional development, the SSC is offering this program to teachers in the Teacher Leaders in Research Based Science Education (TLRRBSE), an ongoing program at the NOAO. This NSF-sponsored program touches the formal education community through a national audience of well-trained and supported middle and high school teachers. The Spitzer educational research program also reaches an additional national audience of students through an informal education program based at the University of Arizona's Astronomy Camp, directed by Dr. Don McCarthy. During this camp, the teachers and their students will learn about the SST through the vast amount of data available in the Spitzer archives.

The General Circulation Model Response to a North Pacific SST Anomaly: Dependence on Time Scale and Pattern Polarity.

NASA Astrophysics Data System (ADS)

Kushnir, Yochanan; Lau, Ngar-Cheung

1992-04-01

A general circulation model was integrated with perpetual January conditions and prescribed sea surface temperature (SST) anomalies in the North Pacific. A characteristic pattern with a warm region centered northeast of Hawaii and a cold region along the western seaboard of North America was alternately added to and subtracted from the climatological SST field. Long 1350-day runs, as well as short 180-day runs, each starting from different initial conditions, were performed. The results were compared to a control integration with climatological SSTs.The model's quasi-stationary response does not exhibit a simple linear relationship with the polarity of the prescribed SST anomaly. In the short runs with a negative SST anomaly over the central ocean, a large negative height anomaly, with an equivalent barotropic vertical structure, occurs over the Gulf of Alaska. For the same SST forcing, the long run yields a different response pattern in which an anomalous high prevails over northern Canada and the Alaskan Peninsula. A significant reduction in the northward heat flux associated with baroclinic eddies and a concomitant reduction in convective heating occur along the model's Pacific storm track. In the runs with a positive SST anomaly over the central ocean, the average height response during the first 90-day period of the short runs is too weak to be significant. In the subsequent 90-day period and in the long run an equivalent barotropic low occurs downstream from the warm SST anomaly. All positive anomaly runs exhibit little change in baroclinic eddy activity or in the patterns of latent heat release. Horizontal momentum transports by baroclinic eddies appear to help sustain the quasi-stationary response in the height field regardless of the polarity of the SST anomaly. These results emphasize the important role played by baroclinic eddies in determining the quasi-stationary response to midlatitude SST anomalies. Differences between the response patterns of the short and long integrations may be relevant to future experimental design for studying air-sea interactions in the extratropies.

Gadoxetic Acid-Enhanced MRI and Sonoelastography: Non-Invasive Assessments of Chemoprevention of Liver Fibrosis in Thioacetamide-Induced Rats with Sho-Saiko-To

PubMed Central

Chen, Ya-Wen; Tsai, Meng-Yuan; Pan, Huay-Ben; Tseng, Hui-Hwa; Hung, Yu-Ting; Chou, Chen-Pin

2014-01-01

Background This study aimed to compare the performance of gadoxetic acid -enhanced magnetic resonance imaging (MRI) and sonoelastography in evaluating chemopreventive effects of Sho-Saiko-To (SST) in thioacetamide (TAA)-induced early liver fibrosis in rats. Materials and Methods Ten of Sprague-Dawley rats receiving TAA (200 mg/kg of body weight) intraperitoneal injection were divided into three groups: Group 1 (TAA only, n = 3), Group 2 (TAA +0.25 g/kg SST, n = 4) and Group 3 (TAA+1 g/kg SST, n = 3). Core needle liver biopsy at week 2 and liver specimens after sacrifice at week 6 confirmed liver fibrosis using histological examinations, including Sirius red staining, Ishak and Metavir scoring systems. Gadoxetic acid-enhanced MRI and shear-wave sonoelastography were employed to evaluate liver fibrosis. The expression of hepatic transporter organic anion transporter 1 (Oatp1), multidrug-resistant protein 2 (Mrp2) and alpha-smooth muscle actin (α-Sma) were also analyzed in each group by immunohistochemistry (IHC) and Western blot. Results According to histological grading by Sirius red staining, Ishak scores of liver fibrosis in Groups 1, 2 and 3 were 3, 2 and 1, respectively. As shown in gadoxetic acid-enhanced MRI, the ratio of relative enhancement was significantly lower in Group 1 (1.87±0.21) than in Group 2 of low-dose (2.82±0.25) and Group 3 of high-dose (2.72±0.12) SST treatment at 10 minutes after gadoxetic acid intravenous injection (p<0.05). Sonoelastography showed that the mean difference before and after experiments in Groups 1, 2 and 3 were 4.66±0.1, 4.4±0.57 and 3±0.4 KPa (p<0.1), respectively. Chemopreventive effects of SST reduced the Mrp2 protein level (p<0.01) but not Oatp1 and α-Sma levels. Conclusion Sonoelastography and gadoxetic acid-enhanced MRI could monitor the treatment effect of SST in an animal model of early hepatic fibrosis. PMID:25490034

Tropical cloud feedbacks and natural variability of climate

NASA Technical Reports Server (NTRS)

Miller, R. L.; Del Genio, A. D.

1994-01-01

Simulations of natural variability by two general circulation models (GCMs) are examined. One GCM is a sector model, allowing relatively rapid integration without simplification of the model physics, which would potentially exclude mechanisms of variability. Two mechanisms are found in which tropical surface temperature and sea surface temperature (SST) vary on interannual and longer timescales. Both are related to changes in cloud cover that modulate SST through the surface radiative flux. Over the equatorial ocean, SST and surface temperature vary on an interannual timescale, which is determined by the magnitude of the associated cloud cover anomalies. Over the subtropical ocean, variations in low cloud cover drive SST variations. In the sector model, the variability has no preferred timescale, but instead is characterized by a 'red' spectrum with increasing power at longer periods. In the terrestrial GCM, SST variability associated with low cloud anomalies has a decadal timescale and is the dominant form of global temperature variability. Both GCMs are coupled to a mixed layer ocean model, where dynamical heat transports are prescribed, thus filtering out El Nino-Southern Oscillation (ENSO) and thermohaline circulation variability. The occurrence of variability in the absence of dynamical ocean feedbacks suggests that climatic variability on long timescales can arise from atmospheric processes alone.

The role of clouds in driving North Atlantic multi-decadal climate variability in observations and models

NASA Astrophysics Data System (ADS)

Clement, A. C.; Bellomo, K.; Murphy, L.

2013-12-01

Large scale warming and cooling periods of the North Atlantic is known as the Atlantic Multidecadal Oscillation (AMO). The pattern of warming and cooling in the North Atlantic Ocean over the 20th century that has a characteristic spatial structure with maximum warming in the mid-latitudes and subtropics. This has been most often attributed to changes in the strength of the Atlantic Meridional Overturning Circulation (AMOC), which in turn affects poleward heat transport. A recent modeling study by Booth et al. (2012), however, suggested that aerosols can explain both the spatial pattern and temporal history of Atlantic SST through indirect effects of aerosols on cloud cover; although this idea is controversial (Zhang et al., 2013). We have found observational evidence that changes in cloud amount can drive SST changes on multi-decadal timescale. We hypothesize that a positive local feedback between SST and cloud radiative effect amplifies SST and gives rise to the observed pattern of SST change. During cool North Atlantic periods, a southward shift of the ITCZ strengthens the trade winds in the tropical North Atlantic and increases low-level cloud cover, which acts to amplify the SST cooling in the North Atlantic. During warm periods in the North Atlantic, the opposite response occurs. We are testing whether the amplitude of this feedback is realistically simulated in the CMIP5 models, and whether inter-model differences in the amplitude of the feedback can explain differences in model simulations of Atlantic multi-decadal variability.

High speed civil transport

NASA Technical Reports Server (NTRS)

1991-01-01

This report discusses the design and marketability of a next generation supersonic transport. Apogee Aeronautics Corporation has designated its High Speed Civil Transport (HSCT): Supercruiser HS-8. Since the beginning of the Concorde era, the general consensus has been that the proper time for the introduction of a next generation Supersonic Transport (SST) would depend upon the technical advances made in the areas of propulsion (reduction in emissions) and material composites (stronger, lighter materials). It is believed by many in the aerospace industry that these beforementioned technical advances lie on the horizon. With this being the case, this is the proper time to begin the design phase for the next generation HSCT. The design objective for a HSCT was to develop an aircraft that would be capable of transporting at least 250 passengers with baggage at a distance of 5500 nmi. The supersonic Mach number is currently unspecified. In addition, the design had to be marketable, cost effective, and certifiable. To achieve this goal, technical advances in the current SST's must be made, especially in the areas of aerodynamics and propulsion. As a result of these required aerodynamic advances, several different supersonic design concepts were reviewed.

Effects of theory of mind performance training on reducing bullying involvement in children and adolescents with high-functioning autism spectrum disorder.

PubMed

Liu, Meng-Jung; Ma, Le-Yin; Chou, Wen-Jiun; Chen, Yu-Min; Liu, Tai-Ling; Hsiao, Ray C; Hu, Huei-Fan; Yen, Cheng-Fang

2018-01-01

Bullying involvement is prevalent among children and adolescents with autism spectrum disorder (ASD). This study examined the effects of theory of mind performance training (ToMPT) on reducing bullying involvement in children and adolescents with high-functioning ASD. Children and adolescents with high-functioning ASD completed ToMPT (n = 26) and social skills training (SST; n = 23) programs. Participants in both groups and their mothers rated the pretraining and posttraining bullying involvement of participants on the Chinese version of the School Bullying Experience Questionnaire. The paired t test was used to evaluate changes in bullying victimization and perpetration between the pretraining and posttraining assessments. Furthermore, the linear mixed-effect model was used to examine the difference in the training effect between the ToMPT and SST groups. The paired t test indicated that in the ToMPT group, the severities of both self-reported (p = .039) and mother-reported (p = .003) bullying victimization significantly decreased from the pretraining to posttraining assessments, whereas in the SST group, only self-reported bullying victimization significantly decreased (p = .027). The linear mixed-effect model indicated that compared with the SST program, the ToMPT program significantly reduced the severity of mother-reported bullying victimization (p = .041). The present study supports the effects of ToMPT on reducing mother-reported bullying victimization in children and adolescents with high-functioning ASD.

On the relationship between the early spring Indian Ocean's sea surface temperature (SST) and the Tibetan Plateau atmospheric heat source in summer

NASA Astrophysics Data System (ADS)

Ji, Chenxu; Zhang, Yuanzhi; Cheng, Qiuming; Li, Yu; Jiang, Tingchen; San Liang, X.

2018-05-01

In this study, we evaluated the effects of springtime Indian Ocean's sea surface temperature (SST) on the Tibetan Plateau's role as atmospheric heat source (AHS) in summer. The SST data of the National Oceanic and Atmospheric Administration (NOAA), European Centre for Medium-Range Weather Forecasts (ECMWF) and the Hadley Centre Sea Ice and Sea Surface Temperature data set (HadISST) and the reanalysis data of the National Center for Environmental Prediction (NCEP) and National Center for Atmospheric Research (NCAR) for 33 years (from 1979 to 2011) were used to analyze the relationship between the Indian Ocean SST and the Tibetan Plateau's AHS in summer, using the approaches that include correlation analysis, and lead-lag analysis. Our results show that some certain strong oceanic SSTs affect the summer plateau heat, specially finding that the early spring SSTs of the Indian Ocean significantly affect the plateau's ability to serve as a heat source in summer. Moreover, the anomalous atmospheric circulation and transport of water vapor are related to the Plateau heat variation.

Effects of turbulence modelling on prediction of flow characteristics in a bench-scale anaerobic gas-lift digester.

PubMed

Coughtrie, A R; Borman, D J; Sleigh, P A

2013-06-01

Flow in a gas-lift digester with a central draft-tube was investigated using computational fluid dynamics (CFD) and different turbulence closure models. The k-ω Shear-Stress-Transport (SST), Renormalization-Group (RNG) k-∊, Linear Reynolds-Stress-Model (RSM) and Transition-SST models were tested for a gas-lift loop reactor under Newtonian flow conditions validated against published experimental work. The results identify that flow predictions within the reactor (where flow is transitional) are particularly sensitive to the turbulence model implemented; the Transition-SST model was found to be the most robust for capturing mixing behaviour and predicting separation reliably. Therefore, Transition-SST is recommended over k-∊ models for use in comparable mixing problems. A comparison of results obtained using multiphase Euler-Lagrange and singlephase approaches are presented. The results support the validity of the singlephase modelling assumptions in obtaining reliable predictions of the reactor flow. Solver independence of results was verified by comparing two independent finite-volume solvers (Fluent-13.0sp2 and OpenFOAM-2.0.1). Copyright © 2013 Elsevier Ltd. All rights reserved.

A Wall-Distance-Free k-ω SST Turbulence Model

NASA Astrophysics Data System (ADS)

Gleize, Vincent; Burnley, Victor

2001-11-01

In the calculation of flows around aircraft and aerodynamic bodies, the Shear-Stress Transport (SST) model by Menter has been used extensively due to its good prediction of flows with adverse pressure gradients. One main drawback of this model is the need to calculate the distance from the wall. While this is not a serious drawback for steady state calculations on non-moving grids, this calculation can become very cumbersome and expensive for unsteady simulations, especially when using unstructured grids. In this case, the wall-distance needs to be determined after each iteration. To avoid this problem, a new model is proposed which provides the benefits of the SST correction and avoids the freestream dependency of the solution, while not requiring the wall-distance. The first results for a wide range of test cases show that this model produces very good agreement with experimental data for flows with adverse pressure gradients, separation zones and shock-boundary layer interactions, closely matching the results obtained with the original SST model. This model should be very useful for unsteady calculations, such as store separation, grid adaptation, and other practical flows.

Sea Surface Temperature Influence on Terrestrial Gross Primary Production along the Southern California Current.

PubMed

Reimer, Janet J; Vargas, Rodrigo; Rivas, David; Gaxiola-Castro, Gilberto; Hernandez-Ayon, J Martin; Lara-Lara, Ruben

2015-01-01

Some land and ocean processes are related through connections (and synoptic-scale teleconnections) to the atmosphere. Synoptic-scale atmospheric (El Niño/Southern Oscillation [ENSO], Pacific Decadal Oscillation [PDO], and North Atlantic Oscillation [NAO]) decadal cycles are known to influence the global terrestrial carbon cycle. Potentially, smaller scale land-ocean connections influenced by coastal upwelling (changes in sea surface temperature) may be important for local-to-regional water-limited ecosystems where plants may benefit from air moisture transported from the ocean to terrestrial ecosystems. Here we use satellite-derived observations to test potential connections between changes in sea surface temperature (SST) in regions with strong coastal upwelling and terrestrial gross primary production (GPP) across the Baja California Peninsula. This region is characterized by an arid/semiarid climate along the southern California Current. We found that SST was correlated with the fraction of photosynthetic active radiation (fPAR; as a proxy for GPP) with lags ranging from 0 to 5 months. In contrast ENSO was not as strongly related with fPAR as SST in these coastal ecosystems. Our results show the importance of local-scale changes in SST during upwelling events, to explain the variability in GPP in coastal, water-limited ecosystems. The response of GPP to SST was spatially-dependent: colder SST in the northern areas increased GPP (likely by influencing fog formation), while warmer SST at the southern areas was associated to higher GPP (as SST is in phase with precipitation patterns). Interannual trends in fPAR are also spatially variable along the Baja California Peninsula with increasing secular trends in subtropical regions, decreasing trends in the most arid region, and no trend in the semi-arid regions. These findings suggest that studies and ecosystem process based models should consider the lateral influence of local-scale ocean processes that could influence coastal ecosystem productivity.

Sea Surface Temperature Influence on Terrestrial Gross Primary Production along the Southern California Current

PubMed Central

Reimer, Janet J.; Vargas, Rodrigo; Rivas, David; Gaxiola-Castro, Gilberto; Hernandez-Ayon, J. Martin; Lara-Lara, Ruben

2015-01-01

Some land and ocean processes are related through connections (and synoptic-scale teleconnections) to the atmosphere. Synoptic-scale atmospheric (El Niño/Southern Oscillation [ENSO], Pacific Decadal Oscillation [PDO], and North Atlantic Oscillation [NAO]) decadal cycles are known to influence the global terrestrial carbon cycle. Potentially, smaller scale land-ocean connections influenced by coastal upwelling (changes in sea surface temperature) may be important for local-to-regional water-limited ecosystems where plants may benefit from air moisture transported from the ocean to terrestrial ecosystems. Here we use satellite-derived observations to test potential connections between changes in sea surface temperature (SST) in regions with strong coastal upwelling and terrestrial gross primary production (GPP) across the Baja California Peninsula. This region is characterized by an arid/semiarid climate along the southern California Current. We found that SST was correlated with the fraction of photosynthetic active radiation (fPAR; as a proxy for GPP) with lags ranging from 0 to 5 months. In contrast ENSO was not as strongly related with fPAR as SST in these coastal ecosystems. Our results show the importance of local-scale changes in SST during upwelling events, to explain the variability in GPP in coastal, water-limited ecosystems. The response of GPP to SST was spatially-dependent: colder SST in the northern areas increased GPP (likely by influencing fog formation), while warmer SST at the southern areas was associated to higher GPP (as SST is in phase with precipitation patterns). Interannual trends in fPAR are also spatially variable along the Baja California Peninsula with increasing secular trends in subtropical regions, decreasing trends in the most arid region, and no trend in the semi-arid regions. These findings suggest that studies and ecosystem process based models should consider the lateral influence of local-scale ocean processes that could influence coastal ecosystem productivity. PMID:25923109

The Ames two-dimensional stratosphere-mesospheric model. [chemistry and transport of SST pollution

NASA Technical Reports Server (NTRS)

Whitten, R. C.; Borucki, W. J.; Watson, V. R.; Capone, L. A.; Maples, A. L.; Riegel, C. A.

1974-01-01

A two-dimensional model of the stratosphere and mesosphere has recently been developed at Ames Research Center. The model contains chemistry based on 18 species that are solved for at each step and a seasonally-varying transport model based on both winds and eddy transport. The model is described and a preliminary assessment of the impact of supersonic aircraft flights on the ozone layer is given.

Modeling SST gradient changes, the hydrological cycle response, and deep water formation in the North Pacific

NASA Astrophysics Data System (ADS)

Burls, N.; Ford, H. L.; Fedorov, A. V.; Jahn, A.; Jacobs, P.

2017-12-01

The absence of deep-water formation and a deep meridional overturning cell in the modern North Pacific has been attributed to the relatively fresh surface conditions in the subarctic. These conditions are, in turn, best explained by the local excess of precipitation over evaporation in the northern Pacific due to net moisture transport from the Atlantic to the Pacific and/or moisture transport associated with the Asian monsoon. Some studies link the lack of deep-water formation in the Pacific directly to its occurrence in the Atlantic via the Atlantic-Pacific seesaw effect and idealized experiments indicate that the smaller width of the Atlantic predisposes it to higher salinity and deep-water formation. We have conducted a series of coupled model experiments across which global mean temperatures and large-scale meridional SST gradients are varied. We perturb either atmospheric CO2 concentrations or the meridional gradient in cloud radiative forcing and run each experiment out to 3000 years so that the deep ocean has equilibrated. As the strength of the meridional temperature gradient decreases across our experiments, a Pacific Meridional Overturning Circulation develops. The strength of this Pacific Meridional Overturning Circulation generally increases as the gradient weakens. In one of these experiments where the meridional SST gradient most closely resembles Pliocene reconstructions, a PMOC exists of comparable in strength to the modern AMOC. We will describe how the hydrological cycle response to reduced meridional SST gradients acts to increase the strength of the PMOC across our sensitivity experiments. Additionally, we will discuss our effort to include carbon isotopes in our Pliocene-like simulation for data-model comparisons. Calcium carbonate accumulation data from Subarctic North Pacific Site 882 and new and previously published carbon isotope records from the Pacific appear to support our modelling results suggesting that weaker meridonal SST gradients during the Pliocene could have supported deep water formation in the subarctic Pacific and a strong PMOC.

North Pacific decadal variability: insights from a biennial ENSO environment

NASA Astrophysics Data System (ADS)

Achuthavarier, Deepthi; Schubert, Siegfried D.; Vikhliaev, Yury V.

2017-08-01

This study examines the mechanisms of the Pacific decadal oscillation (PDO) in the NASA GEOS-5 general circulation model (GCM). Similar to several other state-of-the-art GCMs, the El Niño-Southern Oscillation (ENSO) simulated by the GEOS-5 has a strong biennial periodicity. Since this is a model bias that precludes a strong role of ENSO, it provides a unique environment to assess the other leading mechanisms of North Pacific decadal variability. Despite the biennial ENSO periodicity, the model simulates a realistic PDO pattern in the North Pacific that is resolved as the first empirical orthogonal function (EOF) of winter mean sea surface temperature (SST). The spectrum of the PDO indicates no preferred periodicity. The SST anomalies associated with the PDO, particularly its basin wide structure, are primarily forced by the Aleutian low through Ekman transport. The slow geostrophic transport in association with the meridional adjustment of the subtropical gyre is limited to a narrow region in the Kuroshio-Oyashio extension, north of 40°N. The atmosphere's response to the PDO, while weak, projects onto the North Pacific Oscillation (NPO), a meridional dipole in sea level pressure. Both the lack of preferred periodicity and the weak atmospheric response indicate an air-sea coupled oscillation is an unlikely mechanism in this model. In agreement with recent studies, the NPO is correlated with the North Pacific Gyre Oscillation, which is another leading EOF of North Pacific SST variability. The results emphasize the role of atmospheric variability in the North Pacific SST modes, thereby bringing into question the potential for their predictability.

North Pacific Decadal Variability: Insights from a Biennial ENSO Environment

NASA Technical Reports Server (NTRS)

Achuthavarier, Deepthi; Schubert, Siegfried D.; Vikhliaev, Yury V.

2016-01-01

This study examines the mechanisms of the Pacific decadal oscillation (PDO) in the NASA GEOS-5 general circulation model (GCM). Similar to several other state-of-the-art GCMs, the El Niño-Southern Oscillation (ENSO) simulated by the GEOS-5 has a strong biennial periodicity. Since this is a model bias that precludes a strong role of ENSO, it provides a unique environment to assess the other leading mechanisms of North Pacific decadal variability. Despite the biennial ENSO periodicity, the model simulates a realistic PDO pattern in the North Pacific that is resolved as the first empirical orthogonal function (EOF) of winter mean sea surface temperature (SST). The spectrum of the PDO indicates no preferred periodicity. The SST anomalies associated with the PDO, particularly its basin wide structure, are primarily forced by the Aleutian low through Ekman transport. The slow geostrophic transport in association with the meridional adjustment of the subtropical gyre is limited to a narrow region in the Kuroshio-Oyashio extension, north of 40degN. The atmosphere's response to the PDO, while weak, projects onto the North Pacific Oscillation (NPO), a meridional dipole in sea level pressure. Both the lack of preferred periodicity and the weak atmospheric response indicate an air-sea coupled oscillation is an unlikely mechanism in this model. In agreement with recent studies, the NPO is correlated with the North Pacific Gyre Oscillation, which is another leading EOF of North Pacific SST variability. The results emphasize the role of atmospheric variability in the North Pacific SST modes, thereby bringing into question the potential for their predictability.

Sea surface temperature variability in the Gulf of Mexico from 1734-2008 CE: A reconstruction using cross-dated Sr/Ca records from the coral Siderastrea siderea

NASA Astrophysics Data System (ADS)

DeLong, K. L.; Flannery, J. A.; Quinn, T. M.; Maupin, C. R.; Lin, K.; Shen, C.

2013-12-01

Sea surface temperature (SST) variability in the Gulf of Mexico impacts climate in Central and North America because the Gulf is a major source of moisture and is a source region for the Gulf Stream, which transports ocean heat northward. Here we use skeletal variations in coral Sr/Ca from three Siderastrea siderea coral colonies within the Dry Tortugas National Park in the southeastern Gulf of Mexico (24°42'N, 82°48'W) to develop 274 years of monthly-resolved SST variations. The cross-dated chronology, determined by counting annual density bands and correlating Sr/Ca variations, is verified by four replicated high precision 230Th dates (×1.7-37 years, 2σ). Calibration and verification of our replicated coral Sr/Ca-SST reconstruction with Dry Tortugas SST (r = 0.98 and 0.55 for monthly and 36-month smoothed, respectively; 1992-2008 CE) and Key West, Florida surface air temperature (1895-2008 CE) measurements reveals similar covariance (r = 0.96 and 0.56 for monthly and 36-month smoothed, respectively). The absolute coral SST reconstruction is consistent with SST recorded at the Dry Tortugas lighthouse from 1879-1907 CE indicating that this coral Sr/Ca-SST relationship is stable on centennial time scales. The Sr/Ca-SST reconstruction reveals ~2.0°C interannual variability, ~1.5°C decadal fluctuations, and a 0.7°C warming trend for the past 274 years. Secular variability in our reconstruction is similar to approximately decadally resolved planktic foraminifer Mg/Ca records from the northern Gulf of Mexico. The coral Sr/Ca-SST reconstruction reveals colder decades (~1.5°C) suggesting a reduction in moisture and ocean heat flux from the Gulf of Mexico. We find winter extremes are more variable than summer extremes (×2.2°C vs. ×1.6°C, 2σ) with a stronger warming trend (1°C) in the summers suggesting continued warming may increase coral bleaching.

A reconstruction of sea surface temperature variability in the southeastern Gulf of Mexico from 1734 to 2008 C.E. using cross-dated Sr/Ca records from the coral Siderastrea siderea

USGS Publications Warehouse

DeLong, Kristine L.; Maupin, Christopher R.; Flannery, Jennifer A.; Quinn, Terrence M.; Shen, CC

2014-01-01

This study uses skeletal variations in coral Sr/Ca from three Siderastrea siderea coral colonies within the Dry Tortugas National Park in the southeastern Gulf of Mexico (24°42′N, 82°48′W) to reconstruct monthly sea surface temperature (SST) variations from 1734 to 2008 Common Era (C.E.). Calibration and verification of the replicated coral Sr/Ca-SST reconstruction with local, regional, and historical temperature records reveals that this proxy-temperature relationship is stable back to 1879 C.E. The coral SST reconstruction contains robust interannual (~2.0°C) and multidecadal variability (~1.5°C) for the past 274 years, the latter of which does not covary with the Atlantic Multidecadal Oscillation. Winter SST extremes are more variable than summer SST extremes (±2.2°C versus ±1.6°C, 2σ) suggesting that Loop Current transport in the winter dominates variability on interannual and longer time scales. Summer SST maxima are increasing (+1.0°C for 274 years, σMC = ±0.5°C, 2σ), whereas winter SST minima contain no significant trend. Colder decades (~1.5°C) during the Little Ice Age (LIA) do not coincide with decades of sunspot minima. The coral SST reconstruction contains similar variability to temperature reconstructions from the northern Gulf of Mexico (planktic foraminifer Mg/Ca) and the Caribbean Sea (coral Sr/Ca) suggesting areal reductions in the Western Hemisphere Warm Pool during the LIA. Mean summer coral SST extremes post-1985 C.E. (29.9°C) exceeds the long-term summer average (29.2°C for 1734–2008 C.E.), yet the warming trend after 1985 C.E. (0.04°C for 24 years, σMC = ±0.5, 2σ) is not significant, whereas Caribbean coral Sr/Ca studies contain a warming trend for this interval.

Using Discrete Event Simulation for Programming Model Exploration at Extreme-Scale: Macroscale Components for the Structural Simulation Toolkit (SST).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilke, Jeremiah J; Kenny, Joseph P.

2015-02-01

Discrete event simulation provides a powerful mechanism for designing and testing new extreme- scale programming models for high-performance computing. Rather than debug, run, and wait for results on an actual system, design can first iterate through a simulator. This is particularly useful when test beds cannot be used, i.e. to explore hardware or scales that do not yet exist or are inaccessible. Here we detail the macroscale components of the structural simulation toolkit (SST). Instead of depending on trace replay or state machines, the simulator is architected to execute real code on real software stacks. Our particular user-space threading frameworkmore » allows massive scales to be simulated even on small clusters. The link between the discrete event core and the threading framework allows interesting performance metrics like call graphs to be collected from a simulated run. Performance analysis via simulation can thus become an important phase in extreme-scale programming model and runtime system design via the SST macroscale components.« less

Cloning of TaSST genes associated with water soluble carbohydrate content in bread wheat stems and development of a functional marker.

PubMed

Dong, Yan; Zhang, Yan; Xiao, Yonggui; Yan, Jun; Liu, Jindong; Wen, Weie; Zhang, Yong; Jing, Ruilian; Xia, Xianchun; He, Zhonghu

2016-05-01

We cloned TaSST genes, developed a gene-specific marker for TaSST-D1, and identified three QTL in the Doumai/Shi 4185 RIL population. TaSST-D1 is within one of the three QTL. Sucrose:sucrose-1-fructosyltransferase (1-SST), a critical enzyme in the fructan biosynthetic pathway, is significantly and positively associated with water soluble carbohydrate (WSC) content in bread wheat stems. In the present study, wheat 1-SST genes (TaSST) were isolated and located on chromosomes 4A, 7A and 7D. Sequence analysis of TaSST-D1 revealed 15 single nucleotide polymorphisms (SNP) in the third exon between cultivars with higher and lower WSC content. A cleaved amplified polymorphism sequence (CAPS) marker, WSC7D, based on the polymorphism at position 1216 (C-G) was developed to discriminate the two alleles. WSC7D was located on chromosome 7DS using a recombinant inbred line (RIL) population from a Doumai/Shi 4185 cross, and a set of Chinese Spring nullisomic-tetrasomic lines. TaSST-D1 co-segregated with the CAPS marker WSC7D and was linked to SNP marker BS00108793_51 on chromosome 7DS at a genetic distance of 6.1 cM. It explained 8.8, 10.9, and 11.3% of the phenotypic variances in trials at Beijing and Shijiazhuang as well as the averaged data from those environments, respectively. Two additional QTL (QWSC.caas-4BS and QWSC.caas-7AS) besides TaSST-D1 were mapped in the RIL population. One hundred and forty-nine Chinese wheat cultivars and advanced lines tested in four environments were used to validate a highly significant (P < 0.01) association between WSC7D and WSC content in wheat stems. WSC7D can be used as a gene-specific marker for improvement of stem WSC content in wheat breeding programs.

Somatostatin protects photoreceptor cells against high glucose-induced apoptosis.

PubMed

Arroba, Ana I; Mazzeo, Aurora; Cazzoni, Daniele; Beltramo, Elena; Hernández, Cristina; Porta, Massimo; Simó, Rafael; Valverde, Ángela M

2016-01-01

Many cellular and molecular studies in experimental animals and early retinal function tests in patients with diabetic retinopathy (DR) have shown that retinal neurodegeneration is an early event in the pathogenesis of the disease. Somatostatin (SST) is one of the most important neuroprotective factors synthesized by the retina: SST levels are decreased in parallel to retinal neurodegeneration in early stages of DR. In this study, we characterized the induction of apoptosis (programmed cell death) in a 661W photoreceptor-like cell line cultured under high glucose (HG) conditions and the effect of SST. A 661W photoreceptor-like cell line and retinal explants from 10-week-old male C57BL/6 mice were cultured under HG conditions and treated with SST. Hyperglycemia significantly reduced the cellular viability by increasing the percentage of apoptotic cells, and this effect was ameliorated by SST (p˂0.05). Activation of caspase-8 by hyperglycemia was found in the 661W cells and retinal explants and decreased in the presence of SST (p˂0.05). Moreover, we detected activation of calpain-2 associated with hyperglycemia-induced cell death, as well as increased protein tyrosine phosphatase 1B (PTP1B) protein levels; both had a pattern of cleavage that was absent in the presence of SST (p˂0.05). Treatment of the 661W cells and retinal explants with SST for 24 h increased the phosphorylation of type 1 insulin-like growth factor receptor (IGF-IR; tyrosine 1165/1166) and protein kinase B (Akt; serine 473), suggesting this survival signaling is activated in the neuroretina by SST (p˂0.05). This study has provided new mechanistic insights first into the involvement of calpain-2 and PTP1B in the loss of cell survival and increased caspase-8-dependent apoptosis induced by hyperglycemia in photoreceptor cells and second, on the protective effect of SST against apoptosis by the enhancement of IGF-IR-mediated Akt phosphorylation.

Somatostatin protects photoreceptor cells against high glucose–induced apoptosis

PubMed Central

Mazzeo, Aurora; Cazzoni, Daniele; Beltramo, Elena; Hernández, Cristina; Porta, Massimo; Simó, Rafael; Valverde, Ángela M.

2016-01-01

Purpose Many cellular and molecular studies in experimental animals and early retinal function tests in patients with diabetic retinopathy (DR) have shown that retinal neurodegeneration is an early event in the pathogenesis of the disease. Somatostatin (SST) is one of the most important neuroprotective factors synthesized by the retina: SST levels are decreased in parallel to retinal neurodegeneration in early stages of DR. In this study, we characterized the induction of apoptosis (programmed cell death) in a 661W photoreceptor-like cell line cultured under high glucose (HG) conditions and the effect of SST. Methods A 661W photoreceptor-like cell line and retinal explants from 10-week-old male C57BL/6 mice were cultured under HG conditions and treated with SST. Results Hyperglycemia significantly reduced the cellular viability by increasing the percentage of apoptotic cells, and this effect was ameliorated by SST (p˂0.05). Activation of caspase-8 by hyperglycemia was found in the 661W cells and retinal explants and decreased in the presence of SST (p˂0.05). Moreover, we detected activation of calpain-2 associated with hyperglycemia-induced cell death, as well as increased protein tyrosine phosphatase 1B (PTP1B) protein levels; both had a pattern of cleavage that was absent in the presence of SST (p˂0.05). Treatment of the 661W cells and retinal explants with SST for 24 h increased the phosphorylation of type 1 insulin-like growth factor receptor (IGF-IR; tyrosine 1165/1166) and protein kinase B (Akt; serine 473), suggesting this survival signaling is activated in the neuroretina by SST (p˂0.05). Conclusions This study has provided new mechanistic insights first into the involvement of calpain-2 and PTP1B in the loss of cell survival and increased caspase-8-dependent apoptosis induced by hyperglycemia in photoreceptor cells and second, on the protective effect of SST against apoptosis by the enhancement of IGF-IR-mediated Akt phosphorylation. PMID:28050125

Latitudinal and Longitudinal Basin-scale Surface Salinity Contrasts and Freshwater Transport by Ocean Thermohaline Circulation

NASA Astrophysics Data System (ADS)

Seidov, D.; Haupt, B. J.

2003-12-01

The role of sea surface salinity (SSS) contrasts in maintaining vigorous global ocean thermohaline circulation (THC) is revisited. Relative importance of different generalizations of sea surface conditions in climate studies is explored. In numerical experiments using an ocean general circulation model, we have aggregated the observed sea surface temperature (SST) and SSS in several different ways: we used observed unchanged SST with SSS taken as constant (34.25 psu) everywhere; SST unchanged, and SSS zonally averaged globally, i.e., in the whole World Ocean; SST averaged globally, and SSS unchanged; SST zonally averaged globally and SSS zonally averaged basin-wide in individual basins, i.e., in the Atlantic, Indian, Pacific, and Southern Oceans separately; and, finally, both SST and SSS zonally averaged in individual basins. Global zonal averaging removes all longitudinal differences in sea surface climatology among ocean basins. However, latitudinal profiles of zonally averaged parameters preserve the main character of large-scale equator-to-pole sea surface variability. Basin-wide zonal averaging does an even better job of preserving latitudinal distributions within each basin. The results of the experiments could hardly be anticipated a priory. Surprisingly, SST could be used as a 2-D field, or as a zonally-averaged field without much difference in the THC dynamics. Moreover, SST could be averaged either globally, or basin-wide, and it also did not change the overall character of THC. At the same time, THC responded vigorously to how the SSS has been changed. It appeared that the THC structure with the globally averaged SST and basin-wide averaged SSS was very close to the one obtained in the control run (control run operates with 2-D observed SST and SSS). Our main conclusion is that ocean-wide inter-basin sea surface salinity contrasts serve as the major controlling element in global thermohaline circulation. Thermal inter-basin contrasts, as well as longitudinal variation in SSS, are less important than latitudinal thermal gradients and inter-basin salinity contrasts. Details of SSS also decrease in importance as soon as its inter-basin contrasts are retained. This is especially important for paleoclimate and future climate simulations, as only the large-scale inter-basin contrasts of the sea surface conditions really matter.

Interactions Between the Thermohaline Circulation and Tropical Atlantic SST in a Coupled General Circulation Model

NASA Technical Reports Server (NTRS)

Miller, Ron; Jiang, Xing-Jian; Travis, Larry (Technical Monitor)

2001-01-01

Tropical Atlantic SST shows a (statistically well-defined) decadal time scale in a 104-year simulation of unforced variability by a coupled general circulation model (CGCM). The SST anomalies superficially resemble observed Tropical Atlantic variability (TAV), and are associated with changes in the atmospheric circulation. Brazilian rainfall is modulated with a decadal time scale, along with the strength of the Atlantic trade winds, which are associated with variations in evaporation and the net surface heat flux. However, in contrast to observed tropical Atlantic variability, the trade winds damp the associated anomalies in ocean temperature, indicating a negative feedback. Tropical SST anomalies in the CGCM, though opposed by the surface heat flux, are advected in from the Southern Hemisphere mid-latitudes. These variations modulate the strength of the thermohaline circulation (THC): warm, salty anomalies at the equator sink drawing cold, fresh mid-latitude water. Upon reaching the equator, the latter inhibit vertical overturning and advection from higher latitudes, which allows warm, salty anomalies to reform, returning the cycle to its original state. Thus, the cycle results from advection of density anomalies and the effect of these anomalies upon the rate of vertical overturning and surface advection. This decadal modulation of Tropical Atlantic SST and the thermohaline circulation is correlated with ocean heat transport to the Northern Hemisphere high latitudes and Norwegian Sea SST. Because of the central role of equatorial convection, we question whether this mechanism is present in the current climate, although we speculate that it may have operated in palaeo times, depending upon the stability of the tropical water column.

Determination of influence factors and accident rates for the Armored Tractor/Safe Secure Trailer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Phillips, J.S.; Clauss, D.B.; Blower, D.F.

1994-04-01

Operating environments, such as road type, road location, and time of day, play an important role in the observed accident rates of heavy trucks used in general commerce. These same factors influence the accident rate of the Armored Tractor/Safe Secure Trailer (AT/SST) used by the Department of Energy to transport hazardous cargos within the continental United States. This report discusses the development of accident rate influence factors. These factors, based on heavy trucks used in general commerce, are used to modify the observed overall AT/SST accident rate to account for the different operating environments.

Effects of theory of mind performance training on reducing bullying involvement in children and adolescents with high-functioning autism spectrum disorder

PubMed Central

Chen, Yu-Min; Liu, Tai-Ling; Hsiao, Ray C.; Hu, Huei-Fan

2018-01-01

Bullying involvement is prevalent among children and adolescents with autism spectrum disorder (ASD). This study examined the effects of theory of mind performance training (ToMPT) on reducing bullying involvement in children and adolescents with high-functioning ASD. Children and adolescents with high-functioning ASD completed ToMPT (n = 26) and social skills training (SST; n = 23) programs. Participants in both groups and their mothers rated the pretraining and posttraining bullying involvement of participants on the Chinese version of the School Bullying Experience Questionnaire. The paired t test was used to evaluate changes in bullying victimization and perpetration between the pretraining and posttraining assessments. Furthermore, the linear mixed-effect model was used to examine the difference in the training effect between the ToMPT and SST groups. The paired t test indicated that in the ToMPT group, the severities of both self-reported (p = .039) and mother-reported (p = .003) bullying victimization significantly decreased from the pretraining to posttraining assessments, whereas in the SST group, only self-reported bullying victimization significantly decreased (p = .027). The linear mixed-effect model indicated that compared with the SST program, the ToMPT program significantly reduced the severity of mother-reported bullying victimization (p = .041). The present study supports the effects of ToMPT on reducing mother-reported bullying victimization in children and adolescents with high-functioning ASD. PMID:29342210

Validation and optimization of SST k-ω turbulence model for pollutant dispersion within a building array

NASA Astrophysics Data System (ADS)

Yu, Hesheng; Thé, Jesse

2016-11-01

The prediction of the dispersion of air pollutants in urban areas is of great importance to public health, homeland security, and environmental protection. Computational Fluid Dynamics (CFD) emerges as an effective tool for pollutant dispersion modelling. This paper reports and quantitatively validates the shear stress transport (SST) k-ω turbulence closure model and its transitional variant for pollutant dispersion under complex urban environment for the first time. Sensitivity analysis is performed to establish recommendation for the proper use of turbulence models in urban settings. The current SST k-ω simulation is validated rigorously by extensive experimental data using hit rate for velocity components, and the "factor of two" of observations (FAC2) and fractional bias (FB) for concentration field. The simulation results show that current SST k-ω model can predict flow field nicely with an overall hit rate of 0.870, and concentration dispersion with FAC2 = 0.721 and FB = 0.045. The flow simulation of the current SST k-ω model is slightly inferior to that of a detached eddy simulation (DES), but better than that of standard k-ε model. However, the current study is the best among these three model approaches, when validated against measurements of pollutant dispersion in the atmosphere. This work aims to provide recommendation for proper use of CFD to predict pollutant dispersion in urban environment.

Estimates of radiation exposure from solar cosmic rays in SST altitudes

NASA Technical Reports Server (NTRS)

Foelsche, T.

1974-01-01

Factors influencing crew and passenger exposure to solar and galactic cosmic rays that is expected to occur during flights of supersonic transport aircraft are discussed, and some possibilities are considered for decreasing such exposure.

Rapid Cadence Collections with the Space Surveillance Telescope

NASA Astrophysics Data System (ADS)

Monet, David G.; Axelrod, T.; Blake, T.; Claver, C. F.; Lupton, R.; Pearce, E.; Shah, R.; Woods, D.

2013-01-01

The Defense Advanced Research Projects Agency (DARPA) has constructed the 3.5-m Space Surveillance Telescope (SST) on North Oscura Peak in the White Sands Missle Range in New Mexico. The primary goal of the SST program is the monitoring of the Earth's geosynchronous belt for microsatellites and debris. DARPA has announced that SST may also provide the science community a unique asset for astronomical surveys. This paper presents preliminary results from rapid cadence science collections (1.0-sec exposures every 2.5-sec) of a 9.5 square degree area centered near the open cluster M67. The goal of this survey is to find and study astronomical objects whose brightness varies over these short time scales.

Tropical Atlantic-Korea teleconnection pattern during boreal summer season

NASA Astrophysics Data System (ADS)

Ham, Yoo-Geun; Chikamoto, Yoshimitsu; Kug, Jong-Seong; Kimoto, Masahide; Mochizuki, Takashi

2017-10-01

The remote impact of tropical Atlantic sea surface temperature (SST) variability on Korean summer precipitation is examined based on observational data analysis along with the idealized and hindcast model experiments. Observations show a significant correlation (i.e. 0.64) between Korean precipitation anomalies (averaged over 120-130°E, 35-40°N) and the tropical Atlantic SST index (averaged over 60°W-20°E, 30°S-30°N) during the June-July-August (JJA) season for the 1979-2010 period. Our observational analysis and partial-data assimilation experiments using the coupled general circulation model demonstrate that tropical Atlantic SST warming induces the equatorial low-level easterly over the western Pacific through a reorganization of the global Walker Circulation, causing a decreased precipitation over the off-equatorial western Pacific. As a Gill-type response to this diabatic forcing, an anomalous low-level anticyclonic circulation appears over the Philippine Sea, which transports wet air from the tropics to East Asia through low-level southerly, resulting an enhanced precipitation in the Korean peninsula. Multi-model hindcast experiments also show that predictive skills of Korean summer precipitation are improved by utilizing predictions of tropical Atlantic SST anomalies as a predictor for Korean precipitation anomalies.

Interannual Variation in Offshore Advection of Amazon-Orinoco Plume Waters: Observations, Forcing Mechanisms, and Impacts

NASA Astrophysics Data System (ADS)

Fournier, S.; Vandemark, D.; Gaultier, L.; Lee, T.; Jonsson, B.; Gierach, M. M.

2017-11-01

This study investigates sea surface salinity (SSS) and sea surface temperature (SST) variations in the tropical Atlantic east of the Lesser Antilles, a region where freshwater advection from the Amazon and Orinoco Rivers, may potentially impact air-sea interaction. Observations are used to document later-summer variability and evaluate offshore riverine transport from 2010 to 2014. During this period, the largest difference in plume-affected areas, defined as the extent covered by SSS lower than 35.5 pss, is found between 2011 and 2014. Plume waters covered 92% of the study region in 2011 and 60% in 2014, with the average SSS in the study region being 2 pss lower in 2011. Lagrangian particle tracking based on satellite-derived ocean currents is used to diagnose the impact of the river plumes on SSS and SST from 2010 to 2014. Northward freshwater flux in summer 2014 was significantly weaker than fluxes in 2010-2013. This difference is not due to interannual discharge variability, but to significant changes in eddy-driven transport and cross-shore winds. In particular, the stronger cross-shore wind in May 2014 restricted offshore freshwater flow and lead to a smaller plume-affected area. Persistent SST gradients are often found near the plume edge, which may have implications for ocean-atmosphere coupling associated with atmospheric convection. SST in the study region was 1°C higher in 2010 compared to other years, and is related to basin-scale ocean-atmosphere processes. Interannual variation in Amazon advective pathways and the associated SSS changes are also influenced by changes in the ITCZ position between 2011 and 2014.

North-western Mediterranean sea-breeze circulation in a regional climate system model

NASA Astrophysics Data System (ADS)

Drobinski, Philippe; Bastin, Sophie; Arsouze, Thomas; Béranger, Karine; Flaounas, Emmanouil; Stéfanon, Marc

2017-04-01

In the Mediterranean basin, moisture transport can occur over large distance from remote regions by the synoptic circulation or more locally by sea breezes, driven by land-sea thermal contrast. Sea breezes play an important role in inland transport of moisture especially between late spring and early fall. In order to explicitly represent the two-way interactions at the atmosphere-ocean interface in the Mediterranean region and quantify the role of air-sea feedbacks on regional meteorology and climate, simulations at 20 km resolution performed with WRF regional climate model (RCM) and MORCE atmosphere-ocean regional climate model (AORCM) coupling WRF and NEMO-MED12 in the frame of HyMeX/MED-CORDEX are compared. One result of this study is that these simulations reproduce remarkably well the intensity, direction and inland penetration of the sea breeze and even the existence of the shallow sea breeze despite the overestimate of temperature over land in both simulations. The coupled simulation provides a more realistic representation of the evolution of the SST field at fine scale than the atmosphere-only one. Temperature and moisture anomalies are created in direct response to the SST anomaly and are advected by the sea breeze over land. However, the SST anomalies are not of sufficient magnitude to affect the large-scale sea-breeze circulation. The temperature anomalies are quickly damped by strong surface heating over land, whereas the water vapor mixing ratio anomalies are transported further inland. The inland limit of significance is imposed by the vertical dilution in a deeper continental boundary-layer.

Water Vapor Feedback and Links to Mechanisms of Recent Tropical Climate Variations

NASA Technical Reports Server (NTRS)

Robertson, F. R.; Miller, Tim L.

2008-01-01

Recent variations of tropical climate on interannual to near-decadal scales have provided a useful target for studying feedback processes. A strong warm/cold ENSO couplet (e.g. 1997-2000) along with several subsequent weaker events are prominent interannual signals that are part of an apparent longer term strengthening of the Walker circulation during the mid to late1990 s with some weakening thereafter. Decadal scale changes in tropical SST structure during the 1990s are accompanied by focusing of precipitation over the Indo-Pacific warm pool and an increase in tropical ocean evaporation of order 1.0 %/decade. Here we use a number of diverse satellite measurements to explore connections between upper-tropospheric humidity (UTH) variations on these time scales and changes in other water and energy fluxes. Precipitation (GPCP, TRMM), turbulent fluxes (OAFlux), and radiative fluxes (ERBE / CERES, SRB) are use to analyze vertically-integrated divergence of moist static energy, divMSE, and its dry and moist components. Strong signatures of MSE flux transport linking ascending and descending regions of tropical circulations are found. Relative strengths of these transports compared to radiative flux changes are interpreted as a measure of efficiency in the overall process of heat rejection during episodes of warm or cold SST forcing. In conjunction with the diagnosed energy transports we explore frequency distributions of upper-tropospheric humidity as inferred from SSM/T-2 and AMSU-B passive microwave measurements. Relating these variations to SST changes suggests positive water vapor feedback, but at a level reduced from constant relative humidity.

The role of local sea surface temperature pattern changes in shaping climate change in the North Atlantic sector

NASA Astrophysics Data System (ADS)

Hand, Ralf; Keenlyside, Noel S.; Omrani, Nour-Eddine; Bader, Jürgen; Greatbatch, Richard J.

2018-03-01

Beside its global effects, climate change is manifested in many regionally pronounced features mainly resulting from changes in the oceanic and atmospheric circulation. Here we investigate the influence of the North Atlantic SST on shaping the winter-time response to global warming. Our results are based on a long-term climate projection with the Max Planck Institute Earth System Model (MPI-ESM) to investigate the influence of North Atlantic sea surface temperature pattern changes on shaping the atmospheric climate change signal. In sensitivity experiments with the model's atmospheric component we decompose the response into components controlled by the local SST structure and components controlled by global/remote changes. MPI-ESM simulates a global warming response in SST similar to other climate models: there is a warming minimum—or "warming hole"—in the subpolar North Atlantic, and the sharp SST gradients associated with the Gulf Stream and the North Atlantic Current shift northward by a few a degrees. Over the warming hole, global warming causes a relatively weak increase in rainfall. Beyond this, our experiments show more localized effects, likely resulting from future SST gradient changes in the North Atlantic. This includes a significant precipitation decrease to the south of the Gulf Stream despite increased underlying SSTs. Since this region is characterised by a strong band of precipitation in the current climate, this is contrary to the usual case that wet regions become wetter and dry regions become drier in a warmer climate. A moisture budget analysis identifies a complex interplay of various processes in the region of modified SST gradients: reduced surface winds cause a decrease in evaporation; and thermodynamic, modified atmospheric eddy transports, and coastal processes cause a change in the moisture convergence. The changes in the the North Atlantic storm track are mainly controlled by the non-regional changes in the forcing. The impact of the local SST pattern changes on regions outside the North Atlantic is small in our setup.

ENSO related SST anomalies and relation with surface heat fluxes over south Pacific and Atlantic

NASA Astrophysics Data System (ADS)

Chatterjee, S.; Nuncio, M.; Satheesan, K.

2017-07-01

The role of surface heat fluxes in Southern Pacific and Atlantic Ocean SST anomalies associated with El Nino Southern Oscillation (ENSO) is studied using observation and ocean reanalysis products. A prominent dipole structure in SST anomaly is found with a positive (negative) anomaly center over south Pacific (65S-45S, 120W-70W) and negative (positive) one over south Atlantic (50S-30S, 30W-0E) during austral summer (DJF) of El Nino (LaNina). During late austral spring-early summer (OND) of El Nino (LaNina), anomalous northerly (southerly) meridional moisture transport and a positive (negative) sea level pressure anomaly induces a suppressed (enhanced) latent heat flux from the ocean surface over south Pacific. This in turn results in a shallower than normal mixed layer depth which further helps in development of the SST anomaly. Mixed layer thins further due to anomalous shortwave radiation during summer and a well developed SST anomaly evolves. The south Atlantic pole exhibits exactly opposite characteristics at the same time. The contribution from the surface heat fluxes to mixed layer temperature change is found to be dominant over the advective processes over both the basins. Net surface heat fluxes anomaly is also found to be maximum during late austral spring-early summer period, with latent heat flux having a major contribution to it. The anomalous latent heat fluxes between atmosphere and ocean surface play important role in the growth of observed summertime SST anomaly. Sea-surface height also shows similar out-of-phase signatures over the two basins and are well correlated with the ENSO related SST anomalies. It is also observed that the magnitude of ENSO related anomalies over the southern ocean are weaker in LaNina years than in El Nino years, suggesting an intensified tropics-high latitude tele-connection during warm phases of ENSO.

The role of atmospheric internal variability on the prediction skill of interannual North Pacific sea-surface temperatures

NASA Astrophysics Data System (ADS)

Narapusetty, Balachandrudu

2017-06-01

The sensitivity of the sea-surface temperature (SST) prediction skill to the atmospheric internal variability (weather noise) in the North Pacific (20∘-60∘N;120∘E-80∘W) on decadal timescales is examined using state-of-the-art Climate Forecasting System model version 2 (CFS) and a variation of CFS in an Interactive Ensemble approach (CFSIE), wherein six copies of atmospheric components with different perturbed initial states of CFS are coupled with the same ocean model by exchanging heat, momentum and fresh water fluxes dynamically at the air-sea interface throughout the model integrations. The CFSIE experiments are designed to reduce weather noise and using a few ten-year long forecasts this study shows that reduction in weather noise leads to lower SST forecast skill. To understand the pathways that cause the reduced SST prediction skill, two twenty-year long forecasts produced with CFS and CFSIE for 1980-2000 are analyzed for the ocean subsurface characteristics that influence SST due to the reduction in weather noise in the North Pacific. The heat budget analysis in the oceanic mixed layer across the North Pacific reveals that weather noise significantly impacts the heat transport in the oceanic mixed layer. In the CFSIE forecasts, the reduced weather noise leads to increased variations in heat content due to shallower mixed layer, diminished heat storage and enhanced horizontal heat advection. The enhancement of the heat advection spans from the active Kuroshio regions of the east coast of Japan to the west coast of continental United States and significantly diffuses the basin-wide SST anomaly (SSTA) contrasts and leads to reduction in the SST prediction skill in decadal forecasts.

Status of sonic boom methodology and understanding

NASA Technical Reports Server (NTRS)

Darden, Christine M.; Powell, Clemans A.; Hayes, Wallace D.; George, Albert R.; Pierce, Allan D.

1989-01-01

In January 1988, approximately 60 representatives of industry, academia, government, and the military gathered at NASA-Langley for a 2 day workshop on the state-of-the-art of sonic boom physics, methodology, and understanding. The purpose of the workshop was to assess the sonic boom area, to determine areas where additional sonic boom research is needed, and to establish some strategies and priorities in this sonic boom research. Attendees included many internationally recognized sonic boom experts who had been very active in the Supersonic Transport (SST) and Supersonic Cruise Aircraft Research Programs of the 60's and 70's. Summaries of the assessed state-of-the-art and the research needs in theory, minimization, atmospheric effects during propagation, and human response are given.

Evacuation tests from an SST mock-up.

DOT National Transportation Integrated Search

1970-12-01

A comparative study of passenger flow rates through Type I and Type A aircraft door exits was made with two 280-passenger groups from the full-scale Lockheed Supersonic Transport mock-up, mounted in a belly-landing attitude. : The first load of 280 p...

Changes to Yucatán Peninsula precipitation associated with salinity and temperature extremes of the Caribbean Sea during the Maya civilization collapse.

PubMed

Wu, Henry C; Felis, Thomas; Scholz, Denis; Giry, Cyril; Kölling, Martin; Jochum, Klaus P; Scheffers, Sander R

2017-11-20

Explanations of the Classic Maya civilization demise on the Yucatán Peninsula during the Terminal Classic Period (TCP; ~CE 750-1050) are controversial. Multiyear droughts are one likely cause, but the role of the Caribbean Sea, the dominant moisture source for Mesoamerica, remains largely unknown. Here we present bimonthly-resolved snapshots of reconstructed sea surface temperature (SST) and salinity (SSS) variability in the southern Caribbean from precisely dated fossil corals. The results indicate pronounced interannual to decadal SST and SSS variability during the TCP, which may be temporally coherent to precipitation anomalies on the Yucatán. Our results are best explained by changed Caribbean SST gradients affecting the Caribbean low-level atmospheric jet with consequences for Mesoamerican precipitation, which are possibly linked to changes in Atlantic Meridional Overturning Circulation strength. Our findings provide a new perspective on the anomalous hydrological changes during the TCP that complement the oft-suggested southward displacement of the Intertropical Convergence Zone. We advocate for a strong role of Caribbean SST and SSS condition changes and related ocean-atmosphere interactions that notably influenced the propagation and transport of precipitation to the Yucatán Peninsula during the TCP.

Sea surface temperature estimates for the mid-Piacenzian Indian Ocean—Ocean Drilling Program sites 709, 716, 722, 754, 757, 758, and 763

USGS Publications Warehouse

Robinson, Marci M.; Dowsett, Harry J.; Stoll, Danielle K.

2018-01-30

Despite the wealth of global paleoclimate data available for the warm period in the middle of the Piacenzian Stage of the Pliocene Epoch (about 3.3 to 3.0 million years ago [Ma]; Dowsett and others, 2013, and references therein), the Indian Ocean has remained a region of sparse geographic coverage in terms of microfossil analysis. In an effort to characterize the surface Indian Ocean during this interval, we examined the planktic foraminifera from Ocean Drilling Program (ODP) sites 709, 716, 722, 754, 757, 758, and 763, encompassing a wide range of oceanographic conditions. We quantitatively analyzed the data for sea surface temperature (SST) estimation using both the modern analog technique (MAT) and a factor analytic transfer function. The data will contribute to the U.S. Geological Survey (USGS) Pliocene Research, Interpretation and Synoptic Mapping (PRISM) Project’s global SST reconstruction and climate model SST boundary condition for the mid-Piacenzian and will become part of the PRISM verification dataset designed to ground-truth Pliocene climate model simulations (Dowsett and others, 2013).

Pattern Analysis of El Nino and La Nina Phenomenon Based on Sea Surface Temperature (SST) and Rainfall Intensity using Oceanic Nino Index (ONI) in West Java Area

NASA Astrophysics Data System (ADS)

Prasetyo, Yudo; Nabilah, Farras

2017-12-01

Climate change occurs in 1998-2016 brings significant alteration in the earth surface. It is affects an extremely anomaly temperature such as El Nino and La Nina or mostly known as ENSO (El Nino Southern Oscillation). West Java is one of the regions in Indonesia that encounters the impact of this phenomenon. Climate change due to ENSO also affects food production and other commodities. In this research, processing data method is conducted using programming language to process SST data and rainfall data from 1998 to 2016. The data are sea surface temperature from NOAA satellite, SST Reynolds (Sea Surface Temperature) and daily rainfall temperature from TRMM satellite. Data examination is done using analysis of rainfall spatial pattern and sea surface temperature (SST) where is affected by El Nino and La Nina phenomenon. This research results distribution map of SST and rainfall for each season to find out the impacts of El Nino and La Nina around West Java. El Nino and La Nina in Java Sea are occurring every August to February. During El Nino, sea surface temperature is between 27°C - 28°C with average temperature on 27.71°C. Rainfall intensity is 1.0 mm/day - 2.0 mm/day and the average are 1.63 mm/day. During La Nina, sea surface temperature is between 29°C - 30°C with average temperature on 29.06°C. Rainfall intensity is 9.0 mm/day - 10 mm/day, and the average is 9.74 mm/day. The correlation between rainfall and SST is 0,413 which is expresses a fairly strong correlation between parameters. The conclusion is, during La Nina SST and rainfall increase. While during El Nino SST and rainfall decrease. Hopefully this research could be a guideline to plan disaster mitigation in West Java region that is related extreme climate change.

Differences in coastal and oceanic SST trends north of Yucatan Peninsula

NASA Astrophysics Data System (ADS)

Varela, R.; Costoya, X.; Enriquez, C.; Santos, F.; Gómez-Gesteira, M.

2018-06-01

The coastal area north of Yucatan has experienced a cooling SST trend from 1982 to 2015 during the upwelling season (May-September) that contrasts with the warming observed at the adjacent ocean area. Different drivers were analyzed to identify the possible causes of that unusual coastal cooling. Changes in coastal upwelling and in sea-atmosphere heat fluxes are not consistent with the observed coastal cooling. The eastward shift of the Yucatan Current observed over the last decades is hypothesized as the most probable cause of coastal cooling. This shift enhances the vertical transport of cold deeper water to the continental shelf from where it is pumped to the surface by upwelling favorable westerly winds.

Impact of Gulf Stream SST biases on the global atmospheric circulation

NASA Astrophysics Data System (ADS)

Lee, Robert W.; Woollings, Tim J.; Hoskins, Brian J.; Williams, Keith D.; O'Reilly, Christopher H.; Masato, Giacomo

2018-02-01

The UK Met Office Unified Model in the Global Coupled 2 (GC2) configuration has a warm bias of up to almost 7 K in the Gulf Stream SSTs in the winter season, which is associated with surface heat flux biases and potentially related to biases in the atmospheric circulation. The role of this SST bias is examined with a focus on the tropospheric response by performing three sensitivity experiments. The SST biases are imposed on the atmosphere-only configuration of the model over a small and medium section of the Gulf Stream, and also the wider North Atlantic. Here we show that the dynamical response to this anomalous Gulf Stream heating (and associated shifting and changing SST gradients) is to enhance vertical motion in the transient eddies over the Gulf Stream, rather than balance the heating with a linear dynamical meridional wind or meridional eddy heat transport. Together with the imposed Gulf Stream heating bias, the response affects the troposphere not only locally but also in remote regions of the Northern Hemisphere via a planetary Rossby wave response. The sensitivity experiments partially reproduce some of the differences in the coupled configuration of the model relative to the atmosphere-only configuration and to the ERA-Interim reanalysis. These biases may have implications for the ability of the model to respond correctly to variability or changes in the Gulf Stream. Better global prediction therefore requires particular focus on reducing any large western boundary current SST biases in these regions of high ocean-atmosphere interaction.

Effect of the Initial Vortex Size on Intensity Change in the WRF-ROMS Coupled Model

NASA Astrophysics Data System (ADS)

Zhao, Xiaohui; Chan, Johnny C. L.

2017-12-01

Numerous studies have demonstrated that the tropical cyclone (TC) induced sea surface temperature (SST) cooling strongly depends on the preexisting oceanic condition and TC characteristics. However, very few focused on the correlation of SST cooling and the subsequent intensity with TC size. Therefore, a series of idealized numerical experiments are conducted using the Weather Research Forecasting (WRF) model coupled with the Regional Ocean Model System (ROMS) model to understand how the vortex size is related to SST cooling and subsequent intensity changes of a stationary TC-like vortex. In the uncoupled experiments, the radius of maximum wind (RMW) and size (radius of gale-force wind (R17)) both depend on the initial size within the 72 h simulation. The initially small vortex is smaller than the medium and large vortices throughout its life cycle and is the weakest. In other words, thermodynamic processes do not contribute as much to the R17 change as the dynamic processes proposed (e.g., angular momentum transport) in previous studies. In the coupled experiments, the area-averaged SST cooling induced by medium and large TCs within the inner-core region is comparable due to the similar surface winds and thus mixing in the ocean. Although a stronger SST cooling averaged within a larger region outside the inner-core is induced by the larger TC, the intensity of the larger TC is more intense. This is because that the enthalpy flux in the inner-core region is higher in the larger TC than that in the medium and small TCs.

Contrasting spatial structures of Atlantic Multidecadal Oscillation between observations and slab ocean model simulations

NASA Astrophysics Data System (ADS)

Sun, Cheng; Li, Jianping; Kucharski, Fred; Xue, Jiaqing; Li, Xiang

2018-04-01

The spatial structure of Atlantic multidecadal oscillation (AMO) is analyzed and compared between the observations and simulations from slab ocean models (SOMs) and fully coupled models. The observed sea surface temperature (SST) pattern of AMO is characterized by a basin-wide monopole structure, and there is a significantly high degree of spatial coherence of decadal SST variations across the entire North Atlantic basin. The observed SST anomalies share a common decadal-scale signal, corresponding to the basin-wide average (i. e., the AMO). In contrast, the simulated AMO in SOMs (AMOs) exhibits a tripole-like structure, with the mid-latitude North Atlantic SST showing an inverse relationship with other parts of the basin, and the SOMs fail to reproduce the observed strong spatial coherence of decadal SST variations associated with the AMO. The observed spatial coherence of AMO SST anomalies is identified as a key feature that can be used to distinguish the AMO mechanism. The tripole-like SST pattern of AMOs in SOMs can be largely explained by the atmosphere-forced thermodynamics mechanism due to the surface heat flux changes associated with the North Atlantic Oscillation (NAO). The thermodynamic forcing of AMOs by the NAO gives rise to a simultaneous inverse NAO-AMOs relationship at both interannual and decadal timescales and a seasonal phase locking of the AMOs variability to the cold season. However, the NAO-forced thermodynamics mechanism cannot explain the observed NAO-AMO relationship and the seasonal phase locking of observed AMO variability to the warm season. At decadal timescales, a strong lagged relationship between NAO and AMO is observed, with the NAO leading by up to two decades, while the simultaneous correlation of NAO with AMO is weak. This lagged relationship and the spatial coherence of AMO can be well understood from the view point of ocean dynamics. A time-integrated NAO index, which reflects the variations in Atlantic meridional overturning circulation (AMOC) and northward ocean heat transport caused by the accumulated effect of NAO forcing, reasonably well captures the observed multidecadal fluctuations in the AMO. Further analysis using the fully coupled model simulations provides direct modeling evidence that the observed spatial coherence of decadal SST variations across North Atlantic basin can be reproduced only by including the AMOC-related ocean dynamics, and the AMOC acts as a common forcing signal that results in a spatially coherent variation of North Atlantic SST.

A 80-Year Long Coral-Based Temperature Reconstruction for the Last Interglacial from Northern Hispaniola

NASA Astrophysics Data System (ADS)

DeLong, K. L.; Ouellette, G., Jr.; Goodkin, N.; Martin, E. R.; Rosendahl, D. H.; Taylor, F. W.; WU, C. C.; Shen, C. C.

2016-12-01

The Last Interglacial (LIG; 117-128 ka), when sea level was 6 m higher than today, can serve as an analog for future climate scenarios, yet minimal paleoclimatic information exists with seasonal to decadal resolution. The island of Hispaniola is a particularly desirable site for producing sea surface temperature (SST) reconstructions, as it displays significant correlations with SST and precipitation anomalies for much of the tropical and North Atlantic Ocean, and Hispaniola is located in the northern sector of the Atlantic Warm Pool (AWP), a primary moisture source for precipitation in the Americas. Here we present an early LIG (128,626 ±438 (2σ) years) monthly-resolved coral Sr/Ca-SST reconstruction from a well-preserved Siderastrea siderea subfossil coral spanning 80 years from the northern coast of Hispaniola (19.913ºN, 70.925ºW). We compare our LIG SST reconstruction with coral Sr/Ca-SST from three modern coral microatolls of the same species, the longest spanning 80 years, recovered near Port-au Prince, Haiti (18.479070°N, 72.668659°W) after the 2010 Haiti earthquake, as well as a 125 ka LIG model simulation spanning 300 years. We find similar mean SST for the LIG (27.4ºC) and modern corals (27.9ºC) that is consistent with MIS 5e reconstructions in the tropical oceans (27.3-29.6ºC); however, these reconstructions are warmer than the LIG model mean SST for our study site (25.6ºC). Seasonal variability is similar (1.5ºC LIG, 1.0-1.7ºC modern) consistent with the findings of LIG coral reconstructions using the tropical Atlantic coral Diploria strigosa and with climate model simulations suggesting orbital insolation changes driving LIG seasonality. However, our LIG coral contains decadal variability (1.7-3.1ºC) not evident in the shorter LIG coral reconstructions or modern SST records and coral reconstructions yet are present in the LIG model simulation for our study site. This decadal variability may reflect variations in the northern extent of the AWP on decadal time scales, which may vary trade wind strength, westward moisture transport to the Americas, and precipitation in the Atlantic.

Seasonality in the Western Mediterranean During the Last Glacial From Paired Oxygen Isotopes and Mg/Ca in Limpet Shells

NASA Astrophysics Data System (ADS)

Ferguson, J. E.; Henderson, G. M.; Fa, D.; Finlayson, C.

2008-12-01

Molluscs have shown great potential to act as seasonal-resolution archives of sea-surface temperatures (SST) at mid to high latitudes, outside the range of tropical surface corals. Seasonal resolution climate records from higher latitudes are important to allow investigation of the role of seasonality in controlling mean climate on diverse timescales, and of the evolution of climate systems such as the North Atlantic Oscillation. Long sequences of intertidal mollusc shells are difficult to find due to sea level fluctuations over glacial- interglacial periods. This study makes use of Patella shells collected by Neanderthals and humans and transported inland to caves on Gibraltar over at least the last 120 kyrs. Some 30 fossil Patella shells were selected from several hundred excavated from Gorham's and Vanguard Caves at Gibraltar. Oxygen isotope analysis of micromilled samples of modern Patella shells from the Gibraltar coastline demonstrate that the shells accurately record absolute SSTs and capture more than 80% of the full seasonal range. Analysis of fossil Patella shells, dated using 14C, provides records of the change in absolute SST and seasonality during the last glacial. Paired Mg/Ca ratios of micromilled samples in modern Patella shells follow a consistent positive relationship with SST providing an independent paleothermometer, analogous with coral Sr/Ca. Applying this Mg/Ca-SST relationship to fossil Patella shells allows the independent reconstruction of the absolute values and range of SSTs and the reconstruction of seawater δ18O for the western Mediterranean. Results show a cooling of glacial summer SSTs from 36 kyr BP to the LGM with maximum cooling of glacial summer SSTs of 7.5 °C relative to modern. In contrast, winter SSTs show greater variability on millennial timescales with a maximum cooling of up to 10 °C. SST seasonality is therefore extended due to greater winter cooling but SST seasonality is highly variable as a result of large fluctuation in the extent of winter cooling. These results contrast with GCM model estimates of SST values and seasonality during the glacial.

A study on the seasonal variability of upwelling and its effects on physical parameters in Arabian Sea

NASA Astrophysics Data System (ADS)

Shukla, Rohit Kumar; Shaji, Chithra; Ojha, Satya P.; Kumar, Pankaj

2017-04-01

The upwelling in Arabian Sea is an important phenomenon, mainly occurring along the southwest coast of India during summer monsoon, which increases the biological productivity in the region. The south west coast of Arabian sea region accounts for about 53% of fish yield of the total fish production in Arabian Sea, thus it is imperative to study and understand the process of upwelling in this region. To study the upwelling features in southwest coast of India, monthly Ekman mass transport is estimated using analyzed wind and derived products from Oceansat-II scatterometer data. Seasonal variability of Ekman mass transport has been analyzed to study the occurrences of coastal upwelling in this region. Results show prominent region of upwelling along southwest coast of India is between 7° and 15° N. Transport estimate demonstrate that the strong offshore Ekman mass transport, as high as -2000 kg/m/s, was observed during summer monsoon months due to favorable wind conditions. Very weak offshore transport, as low as -200 kg/m/s, was observed during pre-monsoon months as winds were weak and spatially variable. Moderate offshore transport, up to -750 kg/m/s, was observed during winter monsoon months. The upwelling associated ocean surface features such as Sea-surface temperature (SST, from AVHRR), chlorophyll concentration (AQUA-MODIS), wind stress curl derived from Oceansat-II and sea surface salinity (SSS, from Aquarius) were examined to demonstrate the spatial and temporal evolution of upwelling in this region. With the advancement of the summer monsoon and upwelling, the monthly mean SST range reaches up to 26-27°C (August - September) from about 29-30°C (April - May). The monthly mean Chlorophyll concentration reaches up to 25-30 mg/m3 (August-September) from 0.1-0.2 mg/m3 (January-February). The monthly SSS which was observed to be about 34 psu (December 2102- January 2013) reaches to 36.5 psu (August-September). Analysis of SST from different sources suggests that the occurrence of a mini-cold pool (MCP) off the southern tip of India (STI) is a persistent phenomenon which occurs during both the summer and the winter monsoon seasons. The dynamics which governs the occurrence of MCP during the summer monsoon season is mainly due to upwelling, advection of the cold upwelled water from the western Arabian Sea and the southwest coast of India. Since, Somalia upwelling is an established fact, hence, we estimate upwelling only on southwest coast of India to understand the genesis of MCP. Results show that the genesis of MCP off STI starts by June and peaks in August and the SST attains a value as low as 26.0 °C, essentially due to upwelling and advection of upwelled water from the Somalia region along with upwelled water from southwest coast of India.

Wet-to-dry shift over Southwest China in 1994 tied to the warming of tropical warm pool

NASA Astrophysics Data System (ADS)

Wang, Lin; Huang, Gang; Chen, Wen; Zhou, Wen; Wang, Weiqiang

2018-01-01

The autumn climate in Southwest China (SWC) experienced a notable wet-to-dry shift in 1994. Associated with this change in precipitation, decadal signatures of large-scale atmospheric circulation and SST identify a likely dynamical origin: the tropical warm pool (TWP) consisting of tropical northwest Pacific (TNWP, 3°S-12°N and 110°E-150°E) sector and tropical east Indian Ocean (TEI, 10°S-3°N and 80°E-110°E) sector. A cold-to-warm phase switch of TWP SST occurred in 1994, coinciding exactly with the timing of the regime transition of SWC precipitation. During post-1994 period, warm states in the TNWP and TEI sectors plays in a synergistic fashion to invoke dry decades in SWC. On the one side, warm SST over the TNWP sector excites an anomalous cyclone centered on the South China Sea directed opposite to the climatological moisture transport and strengthened zonal wind to its west accompanied by a weakening of the poleward flux; on the other side, warm SST over the TEI sector acts to intensify inflow into TEI with less concurrent transfer of moisture to SWC and to steer moisture to the northern Arabic Sea and away from the SWC-oriented track. Meanwhile, the troposphere over SWC is capped by subsidence, which is jointly contributed by TNWP and TEI. It then follows a reduced moisture supply, suppressed convective activity, and anomalous divergence in SWC, bringing a precipitation deficit there. In contrast, cold TWP SST during 1961-1994 favors wet conditions in SWC, given a perfectly symmetrical circulation pattern. Further, the dominant role of TWP is confirmed, because the modeled response to TWP SST forcing alone bears a great resemblance to the observed evidence. Finally, it is also found that the teleconnected influence induced by TWP is stronger in southern SWC than in northern SWC, which explains the south-north gradient of interdecadal signal of SWC precipitation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ketusky, E.

The U.S. Department of Energy’s (DOE’s) Used Fuel Disposition Campaign (UFDC) Program has transported high-burnup nuclear sister fuel rods from a commercial nuclear power plant for purposes of evaluation and testing. The evaluation and testing of high-burnup used nuclear fuel is integral to DOE initiatives to collect information useful in determining the integrity of fuel cladding for future safe transportation of the fuel, and for determining the effects of aging, on the integrity of UNF subjected to extended storage and subsequent transportation. The UFDC Program, in collaboration with the U.S. Nuclear Regulatory Commission and the commercial nuclear industry, has obtainedmore » individual used nuclear fuel rods for testing. The rods have been received at Oak Ridge National Laboratory (ORNL) for both separate effects testing (SET) and small-scale testing (SST). To meet the research objectives, testing on multiple 6 inch fuel rod pins cut from the rods at ORNL will be performed at Pacific Northwest National Laboratory (PNNL). Up to 10 rod equivalents will be shipped. Options were evaluated for multiple shipments using the 10-160B (based on 4.5 rod equivalents) and a single shipment using the NAC-LWT. Based on the original INL/Virginia Power transfer agreement, the rods are assumed to 152 inches in length with a 0.374-inch diameter. This report provides a preliminary content evaluation for use of the 10-160B and NAC-LWT for transporting those fuel rod pins from ORNL to PNNL. This report documents the acceptability of using these packagings to transport the fuel segments from ORNL to PNNL based on the following evaluations: enrichment, A2 evaluation, Pu-239 FGE evaluation, heat load, shielding (both gamma and neutron), and content weight/structural evaluation.« less

Somatostatin and its receptors contribute in a tissue-specific manner to the sex-dependent metabolic (fed/fasting) control of growth hormone axis in mice

PubMed Central

Córdoba-Chacón, José; Gahete, Manuel D.; Castaño, Justo P.; Kineman, Rhonda D.

2011-01-01

Somatostatin (SST) inhibits growth hormone (GH) secretion and regulates multiple processes by signaling through its receptors sst1–5. Differential expression of SST/ssts may contribute to sex-specific GH pattern and fasting-induced GH rise. To further delineate the tissue-specific roles of SST and sst1–5 in these processes, their expression patterns were evaluated in hypothalamus, pituitary, and stomach of male and female mice under fed/fasted conditions in the presence (wild type) or absence (SST-knockout) of endogenous SST. Under fed conditions, hypothalamic/stomach SST/ssts expression did not differ between sexes, whereas male pituitary expressed more SST and sst2A/2B/3/5A/5TMD2/5TMD1 and less sst1, and male pituitary cell cultures were more responsive to SST inhibitory actions on GH release compared with females. This suggests that local pituitary SST/ssts can contribute to the sexually dimorphic pattern of GH release. Fasting (48 h) reduced stomach sst2A/B and hypothalamic SST/sst2A expression in both sexes, whereas it caused a generalized downregulation of pituitary sst subtypes in male and of sst2A only in females. Thus, fasting can reduce SST sensitivity across tissues and SST input to the pituitary, thereby jointly contributing to enhance GH release. In SST-knockout mice, lack of SST differentially altered sst subtype expression levels in both sexes, supporting an important role for SST in sex-dependent control of GH axis. Evaluation of SST, IGF-I, and glucocorticoid effects on hypothalamic and pituitary cell cultures revealed that these hormones could directly account for alterations in sst2/5 expression in the physiological states examined. Taken together, these results indicate that changes in SST output and sensitivity can contribute critically to precisely define, in a tissue-dependent manner, the sex-specific metabolic regulation of the GH axis. PMID:20943754

Global salinity predictors of western United States precipitation

NASA Astrophysics Data System (ADS)

Liu, T.; Schmitt, R. W.; Li, L.

2016-12-01

Moisture transport from the excess of evaporation over precipitation in the global ocean drives terrestrial precipitation patterns. Sea surface salinity (SSS) is sensitive to changes in ocean evaporation and precipitation, and therefore, to changes in the global water cycle. We use the Met Office Hadley Centre EN4.2.0 SSS dataset to search for teleconnections between autumn-lead seasonal salinity signals and winter precipitation over the western United States. NOAA CPC Unified observational US precipitation in winter months is extracted from bounding boxes over the northwest and southwest and averaged. Lead autumn SON SSS in ocean areas that are relatively highly correlated with winter DJF terrestrial precipitation are filtered by a size threshold and treated as individual predictors. After removing linear trends from the response and explanatory variables and accounting for multiple collinearity, we use best subsets regression and the Bayesian information criterion (BIC) to objectively select the best model to predict terrestrial precipitation using SSS and SST predictors. The combination of autumn SSS and SST predictors can skillfully predict western US winter terrestrial precipitation (R2 = 0.51 for the US Northwest and R2 = 0.7 for the US Southwest). In both cases, SSS is a better predictor than SST. Thus, incorporating SSS can greatly enhance the accuracy of existing precipitation prediction frameworks that use SST-based climate indices and by extension improve watershed management.

Effect of mesoscale oceanic eddies on mid-latitude storm-tracks.

NASA Astrophysics Data System (ADS)

Foussard, Alexis; Lapeyre, Guillaume; Plougonven, Riwal

2017-04-01

Sharp sea surface temperature (SST) gradients associated with oceanic western boundary currents (WBC) exert an influence on the position and intensity of mid-latitude storm-tracks. This occurs through strong surface baroclinicity maintained by cross frontal SST gradient and deep vertical atmospheric motion due to convection on the warm flank of the WBC. However the additional role of mesoscale oceanic structures (30-300km) has not yet been explored although they have a non-negligible influence on surface heat fluxes. Using the Weather Research and Forecasting model, we investigate the potential role of these oceanic eddies in the case of an idealized atmospheric mid-latitude storm track forced by a mesoscale oceanic eddy field superposed with a large-scale SST gradient. Surface latent and sensible fluxes are shown to react with a non-linear response to the SST variations, providing additional heat and moisture supply at large scales. The atmospheric response is not restricted to the boundary layer but reaches the free troposphere, especially through increased water vapor vertical transport and latent heat release. This additional heating in presence of eddies is balanced by a shift of the storm-track and its poleward heat flux toward high latitudes, with amplitude depending on atmospheric configuration and eddies amplitude. We also explore how this displacement of perturbations changes the position and structure of the mid-latitude jet through eddy momentum fluxes.

Analysis of flow disturbance in a stenosed carotid artery bifurcation using two-equation transitional and turbulence models.

PubMed

Tan, F P P; Soloperto, G; Bashford, S; Wood, N B; Thom, S; Hughes, A; Xu, X Y

2008-12-01

In this study, newly developed two-equation turbulence models and transitional variants are employed for the prediction of blood flow patterns in a diseased carotid artery where the growth, progression, and structure of the plaque at rupture are closely linked to low and oscillating wall shear stresses. Moreover, the laminar-turbulent transition in the poststenotic zone can alter the separation zone length, wall shear stress, and pressure distribution over the plaque, with potential implications for stresses within the plaque. Following the validation with well established experimental measurements and numerical studies, a magnetic-resonance (MR) image-based model of the carotid bifurcation with 70% stenosis was reconstructed and simulated using realistic patient-specific conditions. Laminar flow, a correlation-based transitional version of Menter's hybrid k-epsilon/k-omega shear stress transport (SST) model and its "scale adaptive simulation" (SAS) variant were implemented in pulsatile simulations from which analyses of velocity profiles, wall shear stress, and turbulence intensity were conducted. In general, the transitional version of SST and its SAS variant are shown to give a better overall agreement than their standard counterparts with experimental data for pulsatile flow in an axisymmetric stenosed tube. For the patient-specific case reported, the wall shear stress analysis showed discernable differences between the laminar flow and SST transitional models but virtually no difference between the SST transitional model and its SAS variant.

How Robust Are the Surface Temperature Fingerprints of the Atlantic Overturning Meridional Circulation on Monthly Time Scales?

NASA Astrophysics Data System (ADS)

Alexander-Turner, R.; Ortega, P.; Robson, J. I.

2018-04-01

It has been suggested that changes in the Atlantic Meridional Overturning Circulation (AMOC) can drive sea surface temperature (SST) on monthly time scales (Duchez et al., 2016, https://doi.org/10.1002/2017GB005667). However, with only 11 years of continuous observations, the validity of this result over longer, or different, time periods is uncertain. In this study, we use a 120 yearlong control simulation from a high-resolution climate model to test the robustness of the AMOC fingerprints. The model reproduces the observed AMOC seasonal cycle and its variability, and the observed 5-month lagged AMOC-SST fingerprints derived from 11 years of data. However, the AMOC-SST fingerprints are very sensitive to the particular time period considered. In particular, both the Florida current and the upper mid-ocean transport produce highly inconsistent fingerprints when using time periods shorter than 30 years. Therefore, several decades of RAPID observations will be necessary to determine the real impact of the AMOC on SSTs at monthly time scales.

Two-Equation Turbulence Models for Prediction of Heat Transfer on a Transonic Turbine Blade

NASA Technical Reports Server (NTRS)

Garg, Vijay K.; Ameri, Ali A.; Gaugler, R. E. (Technical Monitor)

2001-01-01

Two versions of the two-equation k-omega model and a shear stress transport (SST) model are used in a three-dimensional, multi-block, Navier-Stokes code to compare the detailed heat transfer measurements on a transonic turbine blade. It is found that the SST model resolves the passage vortex better on the suction side of the blade, thus yielding a better comparison with the experimental data than either of the k-w models. However, the comparison is still deficient on the suction side of the blade. Use of the SST model does require the computation of distance from a wall, which for a multiblock grid, such as in the present case, can be complicated. However, a relatively easy fix for this problem was devised. Also addressed are issues such as (1) computation of the production term in the turbulence equations for aerodynamic applications, and (2) the relation between the computational and experimental values for the turbulence length scale, and its influence on the passage vortex on the suction side of the turbine blade.

Results of a preliminary investigation of inlet unstart on a high-speed civil transport airplane concept

NASA Technical Reports Server (NTRS)

Domack, Christopher S.

1992-01-01

The aircraft design engineer of today is tasked with satisfying an increasing number of conflicting requirements. The fact that conflict in these requirements may be technically, economically, or politically motivated usually compounds the difficulty of determining the best solution to a design issue. In this regard, propulsion/airframe integration for supersonic airplanes must rank as one of the most challenging aspects of airplane design. For the cruise Mach numbers currently being considered for High-Speed Civil Transport (HSCT) airplanes, the inlet requirements of low drag, low bleed flow, and high pressure recovery appear to be best met with a mixed-compression design. Unfortunately, these desirable attributes come with a highly undesirable companion: the inlet unstart phenomenon. Concern over the effects of a mixed-compression inlet unstart on the vehicle dynamics of large, high-speed aircraft is not new; a comprehensive wind-tunnel study addressing the problem was published in 1962. Additional investigations of the problem were made throughout the United States SST program and the follow-on NASA program into the late 1970's. The current study sought to examine the magnitude of the problem in order to determine if an inlet unstart posed a potential hazard severe enough to preclude the use of mixed-compression inlets on proposed HSCT concepts.

Implementation and Validation of a Laminar-to-Turbulent Transition Model in the Wind-US Code

NASA Technical Reports Server (NTRS)

Denissen, Nicholas A.; Yoder, Dennis A.; Georgiadis, Nicholas J.

2008-01-01

A bypass transition model has been implemented in the Wind-US Reynolds Averaged Navier-Stokes (RANS) solver. The model is based on the Shear Stress Transport (SST) turbulence model and was built starting from a previous SST-based transition model. Several modifications were made to enable (1) consistent solutions regardless of flow field initialization procedure and (2) fully turbulent flow beyond the transition region. This model is intended for flows where bypass transition, in which the transition process is dominated by large freestream disturbances, is the key transition mechanism as opposed to transition dictated by modal growth. Validation of the new transition model is performed for flows ranging from incompressible to hypersonic conditions.

A binary genetic programing model for teleconnection identification between global sea surface temperature and local maximum monthly rainfall events

NASA Astrophysics Data System (ADS)

Danandeh Mehr, Ali; Nourani, Vahid; Hrnjica, Bahrudin; Molajou, Amir

2017-12-01

The effectiveness of genetic programming (GP) for solving regression problems in hydrology has been recognized in recent studies. However, its capability to solve classification problems has not been sufficiently explored so far. This study develops and applies a novel classification-forecasting model, namely Binary GP (BGP), for teleconnection studies between sea surface temperature (SST) variations and maximum monthly rainfall (MMR) events. The BGP integrates certain types of data pre-processing and post-processing methods with conventional GP engine to enhance its ability to solve both regression and classification problems simultaneously. The model was trained and tested using SST series of Black Sea, Mediterranean Sea, and Red Sea as potential predictors as well as classified MMR events at two locations in Iran as predictand. Skill of the model was measured in regard to different rainfall thresholds and SST lags and compared to that of the hybrid decision tree-association rule (DTAR) model available in the literature. The results indicated that the proposed model can identify potential teleconnection signals of surrounding seas beneficial to long-term forecasting of the occurrence of the classified MMR events.

Consideration of Fuel Requirements for Supersonic Transport Operation

NASA Technical Reports Server (NTRS)

Stickle, Joseph W.

1965-01-01

An analysis of the interaction of operational environment and aircraft characteristics of the supersonic transport (SST) in the areas of design-range and reserve-fuel requirements has been made. Design-range requirements are considered in relation to the effects of wind, temperature, flight-level assignment, and payload variation. An approach toward combining en route and holding reserve requirements while maintaining protection equivalent to that provided subsonic jet transport operations by the present civil air regulation en route plus holding reserves is given. This approach results in a savings in reserve fuel over that required by separate requirements.

Shield evaluation and performance testing at the USMB`s Strategic Structures Testing Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barczak, T.M.; Gearhart, D.F.

1996-12-31

Historically, shield performance testing is conducted by the support manufacturers at European facilities. The U.S. Bureau of Mines (USBM) has conducted extensive research in shield Mechanics and is now opening its Strategic Structures Testing (SST) Laboratory to the mining industry for shield performance testing. The SST Laboratory provides unique shield testing capabilities using the Mine Roof Simulator (MRS) load frame. The MRS provides realistic and cost-effective shield evaluation by combining both vertical and horizontal loading into a single load cycle; whereas, several load cycles would be required to obtain this loading in a static frame. In addition to these advantages,more » the USBM acts as an independent research organization to provide an unbiased assessment of shield performance. This paper describes the USBM`s shield testing program that is designed specifically to simulate in-service mining conditions using the unique the capabilities of the SST Laboratory.« less

Short-term streamflow forecasting with global climate change implications A comparative study between genetic programming and neural network models

NASA Astrophysics Data System (ADS)

Makkeasorn, A.; Chang, N. B.; Zhou, X.

2008-05-01

SummarySustainable water resources management is a critically important priority across the globe. While water scarcity limits the uses of water in many ways, floods may also result in property damages and the loss of life. To more efficiently use the limited amount of water under the changing world or to resourcefully provide adequate time for flood warning, the issues have led us to seek advanced techniques for improving streamflow forecasting on a short-term basis. This study emphasizes the inclusion of sea surface temperature (SST) in addition to the spatio-temporal rainfall distribution via the Next Generation Radar (NEXRAD), meteorological data via local weather stations, and historical stream data via USGS gage stations to collectively forecast discharges in a semi-arid watershed in south Texas. Two types of artificial intelligence models, including genetic programming (GP) and neural network (NN) models, were employed comparatively. Four numerical evaluators were used to evaluate the validity of a suite of forecasting models. Research findings indicate that GP-derived streamflow forecasting models were generally favored in the assessment in which both SST and meteorological data significantly improve the accuracy of forecasting. Among several scenarios, NEXRAD rainfall data were proven its most effectiveness for a 3-day forecast, and SST Gulf-to-Atlantic index shows larger impacts than the SST Gulf-to-Pacific index on the streamflow forecasts. The most forward looking GP-derived models can even perform a 30-day streamflow forecast ahead of time with an r-square of 0.84 and RMS error 5.4 in our study.

A strong summer phytoplankton bloom southeast of Vietnam in 2007, a transitional year from El Niño to La Niña.

PubMed

Zhao, Hui; Zhao, Jian; Sun, Xingli; Chen, Fajin; Han, Guoqi

2018-01-01

Summer upwelling occurs frequently off the southeast Vietnam coast in the western South China Sea (SCS), where summer phytoplankton blooms generally appear during June-August. In this study, we investigate inter-annual variation of Ekman pumping and offshore transport, and its modulation on summer blooms southeast of Vietnam. The results indicate that there are low intensities of summer blooms in El Niño years, under higher sea surface temperatures (SST) and weaker winds. However, a different pattern of monthly chlorophyll a (Chl-a) blooms occurred in summer of 2007, a transitional stage from El Niño to La Niña, with weak (strong) wind and high (low) SST before (after) early July. There is a weak phytoplankton bloom before July 2007 and a strong phytoplankton bloom after July 2007. The abrupt change in the wind intensity may enhance the upwelling associated with Ekman pumping and offshore Ekman transport, bringing more high-nutrient water into the upper layer from the subsurface, and thus leading to an evident Chl-a bloom in the region.

A virtual reality application in role-plays of social skills training for schizophrenia: a randomized, controlled trial.

PubMed

Park, Kyung-Min; Ku, Jeonghun; Choi, Soo-Hee; Jang, Hee-Jeong; Park, Ji-Yeon; Kim, Sun I; Kim, Jae-Jin

2011-09-30

Although social skills training (SST) is an effective approach for improving social skills for schizophrenia, the motivational deficit attenuates its efficacy. Virtual reality (VR) applications have allowed individuals with mental disabilities to enhance their motivation for rehabilitation. We compared SST using VR role-playing (SST-VR) to SST using traditional role-playing (SST-TR). This randomized, controlled trial included 91 inpatients with schizophrenia who were assigned to either SST-VR (n=46) or SST-TR (n=45). Both groups were administered over 10 semiweekly group sessions. An experienced, blinded rater assessed vocal, nonverbal and conversational skills. We also obtained data on motivation for SST and various social abilities. Throughout the 10 sessions, the SST-VR group (n=33) showed greater interest in SST and generalization of the skills than the SST-TR group (n=31). After SST, the SST-VR group improved more in conversational skills and assertiveness than the SST-TR group, but less in nonverbal skills. The VR application in role-plays of SST for schizophrenia may be particularly beneficial in terms of improving the conversational skills and assertiveness, possibly through its advantages in enhancing motivation for SST and generalization of the skills, and thus it may be a useful supplement to traditional SST. Copyright © 2011 Elsevier Ltd. All rights reserved.

Improved atmosphere-ocean coupled modeling in the tropics for climate prediction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Minghua

2015-01-01

We investigated the initial development of the double ITCZ in the Community Climate System Model (CCSM Version 3) in the central Pacific. Starting from a resting initial condition of the ocean in January, the model developed a warm bias of sea-surface temperature (SST) in the central Pacific from 5oS to 10oS in the first three months. We found this initial bias to be caused by excessive surface shortwave radiation that is also present in the standalone atmospheric model. The initial bias is further amplified by biases in both surface latent heat flux and horizontal heat transport in the upper ocean.more » These biases are caused by the responses of surface winds to SST bias and the thermocline structure to surface wind curls. We also showed that the warming biases in surface solar radiation and latent heat fluxes are seasonally offset by cooling biases from reduced solar radiation after the austral summer due to cloud responses and in the austral fall due to enhanced evaporation when the maximum SST is closest to the equator. The warming biases from the dynamic heat transport by ocean currents however stay throughout all seasons once they are developed, which are eventually balanced by enhanced energy exchange and penetration of solar radiation below the mixed layer. Our results also showed that the equatorial cold tongue develops after the warm biases in the south central Pacific, and the overestimation of surface shortwave radiation recurs in the austral summer in each year.« less

Bracketing mid-pliocene sea surface temperature: maximum and minimum possible warming

USGS Publications Warehouse

Dowsett, Harry

2004-01-01

Estimates of sea surface temperature (SST) from ocean cores reveal a warm phase of the Pliocene between about 3.3 and 3.0 Mega-annums (Ma). Pollen records from land based cores and sections, although not as well dated, also show evidence for a warmer climate at about the same time. Increased greenhouse forcing and altered ocean heat transport is the leading candidates for the underlying cause of Pliocene global warmth. However, despite being a period of global warmth, there exists considerable variability within this interval. Two new SST reconstructions have been created to provide a climatological error bar for warm peak phases of the Pliocene. These data represent the maximum and minimum possible warming recorded within the 3.3 to 3.0 Ma interval.

An ex post facto evaluation framework for place-based police interventions.

PubMed

Braga, Anthony A; Hureau, David M; Papachristos, Andrew V

2011-12-01

A small but growing body of research evidence suggests that place-based police interventions generate significant crime control gains. While place-based policing strategies have been adopted by a majority of U.S. police departments, very few agencies make a priori commitments to rigorous evaluations. Recent methodological developments were applied to conduct a rigorous ex post facto evaluation of the Boston Police Department's Safe Street Team (SST) hot spots policing program. A nonrandomized quasi-experimental design was used to evaluate the violent crime control benefits of the SST program at treated street segments and intersections relative to untreated street segments and intersections. Propensity score matching techniques were used to identify comparison places in Boston. Growth curve regression models were used to analyze violent crime trends at treatment places relative to control places. UNITS OF ANALYSIS: Using computerized mapping and database software, a micro-level place database of violent index crimes at all street segments and intersections in Boston was created. Yearly counts of violent index crimes between 2000 and 2009 at the treatment and comparison street segments and intersections served as the key outcome measure. The SST program was associated with a statistically significant reduction in violent index crimes at the treatment places relative to the comparison places without displacing crime into proximate areas. To overcome the challenges of evaluation in real-world settings, evaluators need to continuously develop innovative approaches that take advantage of new theoretical and methodological approaches.

A study on bulk and skin temperature difference using observations from Atlantic and Pacific Coastal regions of United States

NASA Astrophysics Data System (ADS)

Alappattu, Denny P.; Wang, Qing; Yamaguchi, Ryan; Lind, Richard; Reynolds, Mike; Christman, Adam

2017-05-01

Analysis of bulk-skin sea surface temperature (SST) difference form the west and east coasts of United States is presented using the data collected from three field experiments. These experiments were conducted at offshore Duck, North Carolina and in the Monterey Bay of the California coastal region. Bulk SST measurements were made using conventional thermistors from a depth of one meter below the sea level. Infrared radiometers were used to measure the surface skin SST. Depending on measurement depth and prevailing conditions, the bulk SST can differ from skin SST by few tenths of a degree to O(1°C). Difference between bulk and skin SST arise from cools skin and warm layer effects. Bulk-skin SST difference (ΔSST) estimated from east coast observations varied from -0.46°C to 1.24°C. Here, the bulk SST was higher than skin SST most of the time during the observations. This indicates cool skin effect was the dominant factor determining the ΔSST in the east coast. For wind speeds less than 4 m s-1, we also noticed an increase in ΔSST. Additionally, for low winds (<4 m s-1) ΔSST also varied diurnally with the occurrence of generally higher ΔSST in the nighttime in comparison with daytime. Moreover, increase in downwelling longwave radiation reduced the bulk-skin SST difference. ΔSST calculated from the observation in the Monterey bay varied between 2.3° and -2.3°C. This was higher than the variability ΔSST observed at the east coast. Moreover, ΔSST variability observed at west coast was independent of wind speed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chan, R.K.; Otte, C.A.

Saccharomyces cerevisiae MATa cells carrying mutations in either sst1 or sst2 are supersensitive to the G1 arrest induced by ..cap alpha.. factor pheromone. When sst1 mutants were mixed with normal SST/sup +/ cells, the entire population recovered together from ..cap alpha.. factor arrest, suggesting that SST/sup +/ cells helped sst1 mutants to recover. Complementation tests and linkage analysis showed that sst1 and bar1, a mutation which eliminates the ability of MATa cells to act as a ''barrier'' to the diffusion of ..cap alpha.. factor, were lesions in the same genes. These findings suggest that sst1 mutants are defective in recoverymore » from ..cap alpha.. factor arrest because they are unable to degrade the pheromone. In contrast, recovery of sst2 mutants was not potentiated by the presence of SST/sup +/ cells in mixing experiments. When either normal MATa cells or mutant cells carrying defects in sst1 or sst2 were exposed to ..cap alpha.. factor for 1 h and then washed free of the pheromone, the sst2 cells subsequently remained arrested in the absence of ..cap alpha.. factor for a much longer time than SST/sup +/ or sst1 cells. These observations suggest that the defect in sst2 mutants is intrinsic to the cell and is involved in the mechanism of ..cap alpha.. factor action at some step after the initial interaction of the pheromone with the cell. The presence of an sst2 mutation appears to cause a growth debility, since repeated serial subculture of haploid sst2-1 strains led to the accumulation of faster-growing revertants that were pheromone resistant and were mating defective (''sterile'').« less

Turbulence Model Effects on RANS Simulations of the HIFiRE Flight 2 Ground Test Configurations

NASA Technical Reports Server (NTRS)

Georgiadis, Nicholas J.; Mankbadi, Mina R.; Vyas, Manan A.

2014-01-01

The Wind-US Reynolds-averaged Navier-Stokes solver was applied to the Hypersonic International Flight Research Experimentation (HIFiRE) Flight 2 scramjet ground test configuration. Two test points corresponding to flight Mach numbers of 5.9 and 8.9 were examined. The emphasis was examining turbulence model effects on the prediction of flow path pressures. Three variants of the Menter k-omega turbulence model family were investigated. These include the baseline (BSL) and shear stress transport (SST) as well as a modified SST model where the shear stress limiter was altered. Variations in the turbulent Schmidt number were also considered. Choice of turbulence model had a substantial effect on prediction of the flow path pressures. The BSL model produced the highest pressures and the SST model produced the lowest pressures. As expected, the settings for the turbulent Schmidt number also had significant effects on predicted pressures. Small values for the turbulent Schmidt number enabled more rapid mass transfer, faster combustion, and in turn higher flowpath pressures. Optimal settings for turbulence model and turbulent Schmidt number were found to be rather case dependent, as has been concluded in other scramjet investigations.

Satellite evidence of harmful algal blooms and related oceanographic features in the Bohai Sea during autumn 1998

NASA Astrophysics Data System (ADS)

Tang, Danling; Kawamura, Hiroshi; Oh, Im Sang; Baker, Joe

Harmful algal blooms (HABs) are truly global marine phenomena of increasing significance. Some HAB occurrences are different to observe because of their high spatial and temporal variability and their advection, once formed, by surface currents. A serious HAB occurred in the Bohai Sea during autumn 1998, causing the largest fisheries economic loss. The present study analyzes the formation, distribution, and advection of HAB using satellite SeaWiFS ocean color data and other oceanographic data. The results show that the bloom originated in the western coastal waters of the Bohai Sea in early September, and developed southeastward when sea surface temperature (SST) increased to 25 26 °C. The bloom with a high Chl-a concentration (6.5 mg m-3) in center portion covered an area of 60 × 65 km2. At the end of September, the bloom decayed when SST decreased to 22 23 °C. The HAB may have been initiated by a combination of the river discharge nutrients in the west coastal waters and the increase of SST; afterwards it may have been transported eastward by the local circulation that was enhanced by northwesterly winds in late September and early October.

Influence of ocean surface conditions on atmospheric vertical thermodynamic structure and deep convection

NASA Technical Reports Server (NTRS)

Fu, Rong; Del Genio, Anthony D.; Rossow, William B.

1994-01-01

The authors analyze the influence of Sea Surface Temperature (SST) and surface wind divergence on atmospheric thermodynamic structure and the resulting effects on the occurrence of deep convection using National Meteorological Center radiosonde data and International Satellite Cloud Climatology Program data for July 1983-July 1985. The onset of deep convection requires not only the existence of positive convective available potential energy (CAPE), but also an unstable planetary boundary layer (PBL). A stable PBL is observed to suppress deep convection even when CAPE is positive. Variations of SST have a major effect on CAPE, but surface wind divergence can also affect deep convection by changing the lapse rate in the lower troposphere and humidity in the PBL. Specifically, when SST is greater than or equal to 28 C, CAPE is always positive, and surface wind divergence does not qualitatively change the buoyancy profile above the PBL. Strong surface wind divergence, however, stabilizes the PBL so as to suppress the initiation of deep convection. In warm SST regions, CAPE is greater than 0 regardless of assumptions about condensate loading, although the pseudoadiabatic limit is more consistent with the observed deep convection than the reversible moist-adiabatic limit under these circumstances. When SST is less than 27 C, CAPE is usually negative and inhibits convection, but strong surface wind convergence can destabilize the inversion layer and moisten the PBL enough to make the atmosphere neutrally stable in the mean. As a result, deep convection is generally enhanced either when SST is greater than or equal to 28 C in the absence of strong surface wind divergence or when strong surface wind convergence occurs even if SST is less than 27 C. The anomalous suppression of deep convection in the warm area of the equatorial west Pacific lying between the intertropical convergence zone (ITCZ) and south Pacific convergence zone (SPCZ) is probably caused by dryness in the PBL and an inversion in that area. The seasonal cycles of deep convection and surface wind divergence are in phase with the maximum solar radiation and lead SST for one to three months in the central Pacific. The change of PBL relative humidity plays a critical role in the changeover to convective instability in this case. The seasonal change of deep convection and associated clouds seems not to have important effects on the seasonal change of local SST in the central Pacific.

Global Sea Surface Temperature and Ecosystem Change Across the Mid-Miocene Climatic Optimum

NASA Astrophysics Data System (ADS)

Veenstra, T. J. T.; Bakker, V. B.; Sangiorgi, F.; Peterse, F.; Schouten, S.; Sluijs, A.

2016-12-01

Even though the term Mid-Miocene Climatic Optimum (MMCO; ca. 17 to 14 Ma) has been widely used in the literature since the early 1990's, almost no early-middle Miocene sea surface temperature (SST) proxy records have been published that support climate warming across its onset. Benthic (and diagenetically altered planktic) foram δ18O records show a decrease, suggesting (deep) ocean warming and/or Antarctic ice sheet melting. However, reliable absolute SST proxy records are absent from the tropics and very scarce in temperate and polar regions. This leaves the question if the warmth of the MMCO was truly global and how its onset relates to the widely recorded positive (Monterey) carbon isotope excursion and volcanism. Finally, it remains uncertain how marine ecosystems responded to this hypothesized warming. We present organic biomarker SST proxy records (Uk'37 and TEX86) spanning the MMCO for several locations in the Atlantic and Pacific Ocean along a pole-to-pole transect, including Ocean Drilling Program Site 959 in the eastern Tropical Atlantic, ODP Site 643 in the Norwegian Sea, ODP Site 1007 on the Great Bahama Bank and Integrated Ocean Drilling Program Site U1352 off New Zealand. Additionally, we use marine palynology (mostly dinoflagellate cysts) to assess ecosystem change at these locations. The resulting spatial reconstruction of SST change shows that Middle Miocene warming was global. Nevertheless, the records also show distinct regional variability, including relatively large warming in the Norwegian Sea and a damped signal in the southern hemisphere, suggesting pronounced changes in ocean circulation. The onset of the MMCO was marked by prominent changes in ecological and depositional setting at the studied sites, likely also related to ocean circulation changes.

Somatostatin: An endogenous antiepileptic

PubMed Central

Qiu, Cuie

2008-01-01

The neuropeptide somatostatin is highly expressed in brain regions associated with seizures. In hippocampus, SST expression and release is regulated by seizures, and SST-containing neurons within the hilus of the dentate gyrus are sensitive to seizure-induced death. In vivo and in vitro studies suggest that the loss of SST function in the dentate could contribute to epileptogenesis and seizure susceptibility. SST also has inhibitory actions in the CA1 and CA3 hippocampus, indicating this peptide is an important homeostatic regulator throughout the hippocampus. In vivo studies show SST has robust antiepileptic properties, with the major site of action being hippocampus. In rodents, somatostatin receptor subtype 2 (SST2) and SST4 appear to mediate the majority of the antiepileptic actions of SST, with SST2 predominate in rat and SST4 in mouse. Thus SST receptors may be appropriate targets for new antiepileptic drugs, although validation in human tissue is lacking. PMID:18221832

Alkenone based constraints of the hydrological development in the mozambique channel over the last 39, 000 years

NASA Astrophysics Data System (ADS)

Kasper, Sebastian; Castañeda, Isla; Tjallingii, Rik; Brummer, Geert-Jan; Schneider, Ralph; Sininnghe-Damsté, Jaap S.; Schouten, Stefan; van der Meer, Marcel T. J.

2014-05-01

Indian Ocean surface circulation through the Mozambique Channel forms the upstream source for the Agulhas Current, which is the main mechanism for transporting warm and salty waters from the Indian Ocean into the Atlantic via the Agulhas Leakage (Lutjeharms 2006). However, the Agulhas Leakage was reduced substantially during glacial times due to the northward migration of the subtropical fronts and shifts in the wind fields, and resulted in accumulation of warm and saline waters in the Southwest Indian Ocean (Peeters et al., 2004). A better understanding of the interactions between sea surface temperatures (SST) and sea surface salinity (SSS) in the Agulhas source region are fundamental for reconstructing past changes in this surface warm water route of the global conveyor and ocean-continent climate linkage with respect to South Africa. Here we present a record of the stable hydrogen isotope composition of the combined di- and tri- unsaturated alkenones (Dalkenone) that might relate to past SSS variations. We compare the variations of the Dalkenone with UK'37 SST records from sediment core 64PE304-80 located in the Mozambique Channel off the Zambezi River mouth. To estimate the influence of freshwater input at this site the alkenone hydrogen isotope record was compared to BIT Index values and Ca/Ti ratios reflecting the input of soil organic matter and lithogenic material on the core site, respectively. During the last glacial maximum (LGM) and the onset of Heinrich event 1 (HE1) at ~18,000 years, Dalkenone and UK'37 are positively correlated. The Dalkenone is more enriched during HE1 corresponding with high BIT values, increased Ca/Ti ratios, and relatively cold SST values. After ~16 ka, Dalkenone values decrease when UK'37 SST increases throughout the early Holocene, suggesting an increase of the continental precipitation and runoff during periods of increased SST. This period can be related to postglacial warming of the tropical ocean or due to a latitudinal shift in the ITCZ over Africa (e.g. Schefuss et al., 2011). Alternatively, the change in the paleosalinity signal may result from the change in the position of the Zambezi River and transport of the river plume by coastal currents and relative to the core location as a result of eustatic sea level rise. For the late Holocene the Dalkenone record shows relatively stable conditions that are interrupted by an excursion to more positive values from approximately 5000 to 1600 years BP. This excursion could be explained by variations of freshwater input related to the Zambezi run off.

Indonesia sea surface temperature from TRMM Microwave Imaging (TMI) sensor

NASA Astrophysics Data System (ADS)

Marini, Y.; Setiawan, K. T.

2018-05-01

We analysis the Tropical Rainfall Measuring Mission's (TRMM) Microwave Imager (TMI) data to monitor the sea surface temperature (SST) of Indonesia waters for a decade of 2005-2014. The TMI SST data shows the seasonal and interannual SST in Indonesian waters. In general, the SST average was highest in March-May period with SST average was 29.4°C, and the lowest was in June – August period with the SST average was 28.5°C. The monthly SST average fluctuation of Indonesian waters for 10 years tends to increase. The lowest SST average of Indonesia occurred in August 2006 with the SST average was 27.6° C, while the maximum occurred in May 2014 with the monthly SST average temperature was 29.9 ° C.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chan, R.K.; Otte, C.A.

Eight independently isolated mutants which are supersensitive (Sst/sup -/) to the G1 arrest induced by the tridecapeptide pheromone ..cap alpha.. factor were identified by screening mutagenized Saccharomyces cerevisiae MATa cells on solid medium for increased growth inhibition by ..cap alpha.. factor. These mutants carries lesions in two complementation groups, sst1 and sst2. Mutations at the sst1 locus were mating type specific: MATa sst1 cells were supersensitive to ..cap alpha.. factor, but MAT..cap alpha.. sst1 cells were not supersensitive to a factor. In contrast, mutations at the sst2 locus conferred supersensitivity to the pheromones of the opposite mating type on bothmore » MATa and MAT..cap alpha.. cells. Even in the absence of added ..cap alpha.. pheromone, about 10% of the cells in exponentially growing cultures of MATa strains carrying any of three different alleles of sst2 (including the ochre mutation sst2-4) had the aberrant morphology (''shmoo'' shape) that normally develops only after MATa cells are exposed to ..cap alpha.. factor. This ''self-shmooing'' phenotype was genetically linked to the sst2 mutations, although the leakiest allele isolated (sst2-3) did not display this characteristic. Normal MATa/MAT..cap alpha.. diploids do not respond to pheromones; diploids homozygous for an sst2 mutation (MATa/MAT..cap alpha.. sst2-1/sst2-1) were still insensitive to ..cap alpha.. factor. The sst1 gene was mapped to within 6.9 centimorgans of his6 on chromosome IX. The sst2 gene was unlinked to sst1, was not centromere linked, and was shown to be neither linked nor centromere distal to MAT on the right arm of chromosome III.« less

Endothelin-converting enzyme-1 degrades internalized somatostatin-14.

PubMed

Roosterman, Dirk; Kempkes, Cordula; Cottrell, Graeme S; Padilla, Benjamin E; Bunnett, Nigel W; Turck, Christoph W; Steinhoff, Martin

2008-05-01

Agonist-induced internalization of somatostatin receptors (ssts) determines subsequent cellular responsiveness to peptide agonists and influences sst receptor scintigraphy. To investigate sst2A trafficking, rat sst2A tagged with epitope was expressed in human embryonic kidney cells and tracked by antibody labeling. Confocal microscopical analysis revealed that stimulation with sst and octreotide induced internalization of sst2A. Internalized sst2A remained sequestrated within early endosomes, and 60 min after stimulation, internalized sst2A still colocalized with beta-arrestin1-enhanced green fluorescence protein (EGFP), endothelin-converting enzyme-1 (ECE-1), and rab5a. Internalized (125)I-Tyr(11)-SST-14 was rapidly hydrolyzed by endosomal endopeptidases, with radioactive metabolites being released from the cell. Internalized (125)I-Tyr(1)-octreotide accumulated as an intact peptide and was released from the cell as an intact peptide ligand. We have identified ECE-1 as one of the endopeptidases responsible for inactivation of internalized SST-14. ECE-1-mediated cleavage of SST-14 was inhibited by the specific ECE-1 inhibitor, SM-19712, and by preventing acidification of endosomes using bafilomycin A(1). ECE-1 cleaved SST-14 but not octreotide in an acidic environment. The metallopeptidases angiotensin-1 converting enzyme and ECE-2 did not hydrolyze SST-14 or octreotide. Our results show for the first time that stimulation with SST-14 and octreotide induced sequestration of sst2A into early endosomes and that endocytosed SST-14 is degraded by endopeptidases located in early endosomes. Furthermore, octreotide was not degraded by endosomal peptidases and was released as an intact peptide. This mechanism may explain functional differences between octreotide and SST-14 after sst2A stimulation. Moreover, further investigation of endopeptidase-regulated trafficking of neuropeptides may result in novel concepts of neuropeptide receptor inactivation in cancer diagnosis.

Sensitive study of the climatological SST by using ATSR global SST data sets

NASA Astrophysics Data System (ADS)

Xue, Yong; Lawrence, Sean P.; Llewellyn-Jones, David T.

1995-12-01

Climatological sea surface temperature (SST) is an initial step for global climate processing monitoring. A comparison has been made by using Oberhuber's SST data set and two years monthly averaged SST from ATSR thermal band data to force the OGCM. In the eastern Pacific Ocean, these make only a small difference to model SST. In the western Pacific Ocean, the use of Oberhuber's data set gives higher climatological SST than that using ATSR data. The SSTs were also simulated for 1992 using climatological SSTs from two years monthly averaged ATSR data and Oberhuber data. The forcing with SST from ATSR data was found to give better SST simulation than that from Oberhuber's data. Our study has confirmed that ATSR can provide accurate monthly averaged global SST for global climate processing monitoring.

Last Millennium ENSO-Mean State Interactions in the Tropical Pacific

NASA Astrophysics Data System (ADS)

Wyman, D. A.; Conroy, J. L.; Karamperidou, C.

2017-12-01

The nature and degree of interaction between the mean state of the tropical Pacific and ENSO remains an open question. Here we use high temporal resolution, tropical Pacific sea surface temperature (SST) records from the last millennium to investigate the relationship between ENSO and the tropical Pacific zonal sea surface temperature gradient (hereafter dSST). A dSST time series was created by standardizing, interpolating, and compositing 7 SST records from the western and 3 SST records from the eastern tropical Pacific. Propagating the age uncertainty of each of these records was accomplished through a Monte Carlo Empirical Orthogonal Function analysis. We find last millennium dSST is strong from 700 to 1300 CE, begins to weaken at approximately 1300 CE, and decreases more rapidly at 1700 CE. dSST was compared to 14 different ENSO reconstructions, independent of the records used to create dSST, to assess the nature of the ENSO-mean state relationship. dSST correlations with 50-year standard deviations of ENSO reconstructions are consistently negative, suggesting that more frequent, strong El Niño events on this timescale reduces dSST. To further assess the strength and direction of the ENSO-dSST relationship, moving 100-year standard deviations of ENSO reconstructions were compared to moving 100-year averages of dSST using Cohen's Kappa statistic, which measures categorical agreement. The Li et al. (2011) and Li et al. (2013) Nino 3.4 ENSO reconstructions had the highest agreement with dSST (k=0.80 and 0.70, respectively), with greater ENSO standard deviation coincident with periods of weak dSST. Other ENSO reconstructions showed weaker agreement with dSST, which may be partly due to low sample size. The consistent directional agreement of dSST with ENSO, coupled with the inability of strong ENSO events to develop under a weak SST gradient, suggests periods of more frequent strong El Niño events reduced tropical Pacific dSST on centennial timescales over the last millennium.

A biomarker perspective on dust, productivity, and sea surface temperature in the Pacific sector of the Southern Ocean

NASA Astrophysics Data System (ADS)

Jaeschke, Andrea; Wengler, Marc; Hefter, Jens; Ronge, Thomas A.; Geibert, Walter; Mollenhauer, Gesine; Gersonde, Rainer; Lamy, Frank

2017-05-01

In this study, we present a new multiproxy data set of terrigenous input, marine productivity and sea surface temperature (SST) from 52 surface sediment samples collected along E-W transects in the Pacific sector of the Southern Ocean. Allochthonous terrigenous input was characterized by the distribution of plant wax n-alkanes and soil-derived branched glycerol dialkyl glycerol tetraethers (brGDGTs). 230Th-normalized burial of both compound groups were highest close to the potential sources in Australia and New Zealand and are strongly related to lithogenic contents (232Th), indicating common sources and transport. Detection of both long-chain n-alkanes and brGDGTs at the most remote sites in the open ocean strongly suggests a primarily eolian transport mechanism to at least 110°W, i.e. by prevailing westerly winds. Two independent organic SST proxies were used, the U37K‧ based on alkenones, and the TEX86 based on isoprenoid GDGTs. Both, U37K‧ and TEX86 indices show robust relationships with temperature over a temperature range between 0.5 and 20 °C, likely implying different seasonal and regional imprints on the temperature signal. Alkenone-based temperature estimates best reflect modern summer SST in the study area when using the polar calibration of Sikes et al. (1997). In contrast, TEX86-derived temperatures may reflect a subsurface signal rather than surface. 230Th-normalized burial of alkenones is highest close to the Subtropical Front and is positively related to the deposition of lithogenic material throughout the study area. In contrast, highest isoGDGT burial south of the Antarctic Polar Front may be largely controlled by diatom blooms, and thus high opal fluxes during austral summer.

Coherent response of the Indo-African boreal summer monsoon to Pacific SST captured in Ethiopian rain δ18O

NASA Astrophysics Data System (ADS)

Madhavan, M.; Palliyil, L. R.; Ramesh, R.

2017-12-01

Pacific Sea Surface Temperature (SST) plays an important role in the inter-annual to inter-decadal variability of boreal monsoons. We identified a common mode of inter annual variability in the Indian and African boreal summer monsoon (June to September) rainfalls, which is linked to Pacific SSTs, using Empirical Orthogonal Function (EOF) analysis. Temporal coefficients (Principle component: PC1) of the leading mode of variability (EOF-1) is well correlated with the Indian summer monsoon rainfall and Sahel rainfall. About forty year long monthly observations of δ18O (and δD) at Addis Ababa, Ethiopia show a strong association with PC1 (r=0.69 for δ18O and r=0.75 for δD). Analysis of SST, sea level pressure and lower tropospheric winds suggest that 18O depletion in Ethiopian rainfall (and wet phases of PC1) is associated with cooler eastern tropical Pacific and warmer western Pacific and strengthening of Pacific subtropical high in both the hemispheres. Associated changes in the trade winds cause enhanced westerly moisture transport into the Indian subcontinent and northern Africa and cause enhanced rainfall. The intrusion of Atlantic westerly component of moisture transport at Addis Ababa during wet phases of PC1 is clearly recorded in δ18O of rain. We also observe the same common mode of variability (EOF1) of Indo-African boreal summer monsoon rain on decadal time scales. A 100 year long δ18O record of actively growing speleothem from the Mechara cave, Ethiopia, matches very well with the PC1 on the decadal time scale. This highlights the potential of speleothem δ18O and leaf wax δD from Ethiopia to investigate the natural variability and teleconnections of Indo-African boreal monsoon.

Diagnosing the leading mode of interdecadal covariability between the Indian Ocean sea surface temperature and summer precipitation in southern China

NASA Astrophysics Data System (ADS)

Liu, Jingpeng; Ren, Hong-Li; Li, Weijing; Zuo, Jinqing

2018-03-01

Precipitation in southern China during boreal summer (June to August) shows a substantial interdecadal variability on the timescale longer than 8 years. In this study, based on the analysis of singular value decomposition, we diagnose the leading mode of interdecadal covariability between the observational precipitation in southern China and the sea surface temperature (SST) in the Indian Ocean. Results indicate that there exist a remarkable southern China zonal dipole (SCZD) pattern of interdecadal variability of summer precipitation and an interdecadal Indian Ocean basin mode (ID-IOBM) of SST. It is found that the SCZD is evidently covaried with the ID-IOBM, which may induce anomalous inter-hemispheric vertical circulation and atmospheric Kelvin waves. During the warm phase of the ID-IOBM, an enhanced lower-level convergence and upper-level divergence exist over the tropical Indian Ocean, which is a typical Gill-Matsuno-type response to the SST warming. Meanwhile, the accompanied upper-level outflow anomalies further converge over the Indo-China peninsula, resulting in a lower-level anticyclone that contributes to reduction of the eastward moisture transport from the Bay of Bengal to the west part of southern China. In addition, the Kelvin wave-like pattern, as a response of the warm ID-IOBM phase, further induces the lower-level anticyclonic anomaly over the South China Sea-Philippines. Such an anticyclonic circulation is favorable for more water vapor transport from the East China Sea into the east part of southern China. Therefore, the joint effects of the anomalous inter-hemispheric vertical circulation and the Kelvin wave-like pattern associated with the ID-IOBM may eventually play a key role in generating the SCZD pattern.

Relative roles of aerosols, SST, and snow impurity on snowmelt over the Tibetan Plateau and its their impacts on South Asian summer monsoon

NASA Astrophysics Data System (ADS)

Kim, K. M.; Tsay, S. C.; Lau, W. K. M.; Yasunari, T. J.; Mahanama, S. P. P.; Koster, R. D.; daSilva, A.

2017-12-01

We examine the relative roles of atmospheric aerosol radiative forcing, year-to-year SST (sea surface temperature) variability, and surface radiative forcing by snow impurity on snowmelt over the Tibetan Plateau and their impacts on rainfall and circulation of South Asian summer monsoon. Five-member ensemble experiments are conducted with NASA's GEOS-5 (Goddard Earth Observing System model version 5), equipped with a snow darkening module - GOSWIM (GOddard SnoW Impurity Module), on the Water-Year 2008 (October 2007 to September 2008). Asian summer monsoon in 2008 was near normal in terms of monsoon rainfall over India subcontinent. However, rainfall was excessive in the North while the southern India suffered from the rainfall deficit. The 2008 summer monsoon was accompanied with high loading of aerosols in the Arabian Sea and La Niña condition in the tropical Pacific. To examine the roles high aerosol loading and La Niña condition on the north-south dipole in Indian monsoon rainfall, two sets of experiments, in addition to control runs (CNTRL), are conducted without SST anomalies (CSST) and aerosol radiative feedback (NRF), respectively. Results show that increased aerosol loading in early summer is associated with the increased dust transport during La Niña years. Increased aerosols over the northern India induces EHP-like (elevated heat pump) circulation and increases rainfall over the India subcontinent. Aerosol radiative forcing feedback (CNTRL-NRF) strengthens the EHP-like monsoon circulation even more. Results indicate that anomalous circulation associated with La Niña condition increases aerosol loading by enhancing dust transport as well as by increasing aerosol lifetime. Increased aerosols induces EHP-like feedback processes and increases rainfall over the India subcontinent.

Spacecraft thermal balance testing using infrared sources

NASA Technical Reports Server (NTRS)

Tan, G. B. T.; Walker, J. B.

1982-01-01

A thermal balance test (controlled flux intensity) on a simple black dummy spacecraft using IR lamps was performed and evaluated, the latter being aimed specifically at thermal mathematical model (TMM) verification. For reference purposes the model was also subjected to a solar simulation test (SST). The results show that the temperature distributions measured during IR testing for two different model attitudes under steady state conditions are reproducible with a TMM. The TMM test data correlation is not as accurate for IRT as for SST. Using the standard deviation of the temperature difference distribution (analysis minus test) the SST data correlation is better by a factor of 1.8 to 2.5. The lower figure applies to the measured and the higher to the computer-generated IR flux intensity distribution. Techniques of lamp power control are presented. A continuing work program is described which is aimed at quantifying the differences between solar simulation and infrared techniques for a model representing the thermal radiating surfaces of a large communications spacecraft.

Sea Surface Salinity Variability from Simulations and Observations: Preparing for Aquarius

NASA Technical Reports Server (NTRS)

Jacob, S. Daniel; LeVine, David M.

2010-01-01

Oceanic fresh water transport has been shown to play an important role in the global hydrological cycle. Sea surface salinity (SSS) is representative of the surface fresh water fluxes and the upcoming Aquarius mission scheduled to be launched in December 2010 will provide excellent spatial and temporal SSS coverage to better estimate the net exchange. In most ocean general circulation models, SSS is relaxed to climatology to prevent model drift. While SST remains a well observed variable, relaxing to SST reduces the range of SSS variability in the simulations (Fig.1). The main objective of the present study is to simulate surface tracers using a primitive equation ocean model for multiple forcing data sets to identify and establish a baseline SSS variability. The simulated variability scales are compared to those from near-surface argo salinity measurements.

Variation in the Norwegian gyre and its links to the termohaline circulation (THC).

NASA Astrophysics Data System (ADS)

Gunnarson, B. E.; Linderholm, H. W.; Wilson, R.; Rydval, M.

2017-12-01

Summer temperature patterns in Scandinavia are partly governed by variations in the North Atlantic drift (being part of the Gulf Stream) causing northern Europe to be warmer than similar latitudes. Observation show that northwestern European climate is strongly link to sea surface temperature (SST) and the ocean circulation (the Norwegian gyre, NG) in the Norwegian Sea. On decadal- multidecadal time scales, there is also positive association with the sub-tropical gyre, but also a weaker (and negative) connection to the sub Polar gyre (SPG) which is linked to the thermohaline circulation (THC). The negative correlations occur only during the April-June and July-September (JAS) seasons, when the ocean mixed layer is shallow in the North Atlantic. A network of Maximum Latewood Density (MXD) tree-ring chronologies from 7 sites in Northern Scandinavia, 1 in central Scotland and 1 in Labrador was used to identifying SST influences on local to regional summer temperatures patterns during 1901-20XX. The sites represent tree growth strongly correlated with mean JAS temperatures (Fennoscandia r > 0.7, Scotland r > 0.6, Labrador r > 0.5). Both the Scotland and Labrador chronologies correlates only with SST from adjacent coastal areas. The Fennoscandian chronologies showed strong and temporally consistent correlations with SST across the NG (r > 0.5), but also positive correlations of the same magnitude across the sub-tropical gyre. In addition, a negative, but weaker, correlation was found over the SPG domain. Climate models (PMIP5) were not able to reproduce the correlation patterns evident in both observations and tree-ring data. The tripolar correlation pattern suggests that North Atlantic SST influences summer temperature variability in Northern Fennoscandia, illustrating the potential for using tree-rings to reconstruct the THC and the heat transport towards the North Atlantic region and atmosphere- ocean interaction back in time.

Forced Atlantic Multidecadal Variability Over the Past Millennium

NASA Astrophysics Data System (ADS)

Halloran, P. R.; Reynolds, D.; Scourse, J. D.; Hall, I. R.

2016-02-01

Paul R. Halloran, David J. Reynolds, Ian R. Hall and James D. Scourse Multidecadal variability in Atlantic sea surface temperatures (SSTs) plays a first order role in determining regional atmospheric circulation and moisture transport, with major climatic consequences. These regional climate impacts range from drought in the Sahel and South America, though increased hurricane activity and temperature extremes, to modified monsoonal rainfall. Multidecadal Atlantic SST variability could arise through internal variability in the Atlantic Meridional Overturning Circulation (AMOC) (e.g., Knight et al., 2006), or through externally forced change (e.g. Booth et al., 2012). It is critical that we know whether internal or external forcing dominates if we are to provide useful near-term climate projections in the Atlantic region. A persuasive argument that internal variability plays an important role in Atlantic Multidecadal Variability is that periodic SST variability has been observed throughout much of the last millennium (Mann et al., 2009), and the hypothesized external forcing of historical Atlantic Multidecadal Variability (Booth et al., 2012) is largely anthropogenic in origin. Here we combine the first annually-resolved millennial marine reconstruction with multi-model analysis, to show that the Atlantic SST variability of the last millennium can be explained by a combination of direct volcanic forcing, and indirect, forced, AMOC variability. Our results indicate that whilst climate models capture the timing of both the directly forced SST and forced AMOC-mediated SST variability, the models fail to capture the magnitude of the forced AMOC change. Does this mean that models underestimate the 21st century reduction in AMOC strength? J. Knight, C. Folland and A. Scaife., Climate impacts of the Atlantic Multidecadal Oscillation, GRL, 2006 B.B.B Booth, N. Dunstone, P.R. Halloran et al., Aerosols implicated as a prime driver of twentieth-century North Atlantic climate variability, Nature, 2012 M.E. Mann, Z. Zhang, S. Rutherford et al., Global Signatures and Dynamical Origins of the Little Ice Age and Medieval Climate Anomaly, Science, 2009

The Relationships between Tropical Pacific and Atlantic SST and Northeast Brazil Monthly Precipitation.

NASA Astrophysics Data System (ADS)

Bertacchi Uvo, Cintia; Repelli, Carlos A.; Zebiak, Stephen E.; Kushnir, Yochanan

1998-04-01

The monthly patterns of northeast Brazil (NEB) precipitation are analyzed in relation to sea surface temperature (SST) in the tropical Pacific and Atlantic Oceans, using singular value decomposition. It is found that the relationships between precipitation and SST in both basins vary considerably throughout the rainy season (February-May). In January, equatorial Pacific SST is weakly correlated with precipitation in small areas of southern NEB, but Atlantic SST shows no significant correlation with regional precipitation. In February, Pacific SST is not well related to precipitation, but south equatorial Atlantic SST is positively correlated with precipitation over the northern Nordeste, the latter most likely reflecting an anomalously early (or late) southward migration of the ITCZ precipitation zone. During March, equatorial Pacific SST is negatively correlated with Nordeste precipitation, but no consistent relationship between precipitation and Atlantic SST is found. Atlantic SST-precipitation correlations for April and May are the strongest found among all months or either ocean. Precipitation in the Nordeste is positively correlated with SST in the south tropical Atlantic and negatively correlated with SST in the north tropical Atlantic. These relationships are strong enough to determine the structure of the seasonal mean SST-precipitation correlations, even though the corresponding patterns for the earlier months of the season are quite different. Pacific SST-precipitation correlations for April and May are similar to those for March. Extreme wet (dry) years for the Nordeste occur when both Pacific and Atlantic SST patterns for April and May occur simultaneously. A separate analysis reinforces previous findings in showing that SST in the tropical Pacific and the northern tropical Atlantic are positively correlated and that tropical Pacific-south Atlantic correlations are negligible.Time-lagged analyses show the potential for forecasting either seasonal mean or monthly precipitation patterns with some degree of skill. In some instances, individual monthly mean SST versus seasonal mean (February-May) precipitation relationships differ considerably from the corresponding monthly SST versus monthly precipitation relationships. It is argued that the seasonal mean relationships result from the relatively strong monthly relationships toward the end of the season, combined with the considerable persistence of SST in both oceans.

Differential somatostatin, CXCR4 chemokine and endothelin A receptor expression in WHO grade I-IV astrocytic brain tumors.

PubMed

Lange, Franziska; Kaemmerer, Daniel; Behnke-Mursch, Julianne; Brück, Wolfgang; Schulz, Stefan; Lupp, Amelie

2018-04-25

Glioblastomas represent the most common primary malignant tumor of the nervous system and the most frequent type of astrocytic tumors. Despite improved therapeutic options, prognosis has remained exceptionally poor over the last two decades. Therefore, new treatment approaches are urgently needed. An overexpression of somatostatin (SST) as well as chemokine CXCR4 and endothelin A (ETA) receptors has been shown for many types of cancer. Respective expression data for astrocytic brain tumors, however, are scarce and contradictory. SST subtype, CXCR4 and ETA expression was comparatively evaluated in a total of 57 grade I-IV astrocytic tumor samples by immunohistochemistry using well-characterized monoclonal antibodies. Overall, receptor expression on the tumor cells was only very low. SST5 was the most prominently expressed receptor, followed by SST3, ETA, SST2 and CXCR4. In contrast, tumor capillaries displayed strong SST2, SST3, SST5, CXCR4 and ETA expression. Presence of SST5, CXCR4 and ETA on tumor cells and of SST3, CXCR4 and ETA on microvessels gradually increased from grade II to grade IV tumors. Ki-67 values correlated significantly with CXCR4 expression on tumor cells and with vascular SST3, CXCR4 or ETA positivity. SST5 or CXCR4 positivity of tumor cells and vascular SST3 or CXCR4 expression negatively correlated with patient outcome. Though having some prognostic value, SST, CXCR4 or ETA expression on astrocytic tumor cells is clearly of no therapeutic relevance. Indirect targeting of these highly vascularized tumors via SST3, SST5, CXCR4 or ETA on the microvessels, in contrast, may represent a promising additional therapeutic strategy.

Protective role of somatostatin receptor 2 against retinal degeneration in response to hypoxia.

PubMed

Dal Monte, Massimo; Latina, Valentina; Cupisti, Elena; Bagnoli, Paola

2012-05-01

In mouse retinal explants, octreotide, a somatostatin [somatotropin release-inhibiting factor (SRIF)] receptor 2 (sst(2)) agonist, prevents the hypoxia-induced vascular endothelial growth factor upregulation. In mice with oxygen-induced retinopathy (OIR), a model of retinopathy of prematurity, either sst(2) overexpression or octreotide have been found to limit hypoxia-induced angiogenic processes. Here, we investigated whether sst(2) influences retinal degeneration in response to hypoxia in wild-type (WT), sst(1)- and sst(2)-knockout (KO) mice. In retinal explants, we determined the role of sst(2) on apoptotic signals. In control condition, caspase-3 activity and the Bax/Bcl-2 ratio were lower in sst(1)-KO than in WT, but higher in sst(2)-KO than in WT retinas. In all strains, a comparable increase in caspase-3 activity and the Bax/Bcl-2 ratio was observed after hypoxia. The hypoxia-induced increase in apoptotic signals was recovered by octreotide in both WT and sst(1)-KO retinas. To investigate the role of sst(2) on retinal function, we recorded electroretinogram (ERG) in response to light flashes in OIR mice. ERG responses did not differ between WT and KO mice with the exception of oscillatory potentials (OPs) which, in sst(1)-KO mice, displayed much larger amplitude. In all strains, hypoxia drastically reduced a-, b-waves and OPs. In both WT and sst(1)-KO mice, octreotide recovered a- and b-waves, but did not recover OPs in sst(1)-KO mice. Neither apoptotic signals nor ERG was affected by octreotide in sst(2)-KO mice. These results show that sst(2) may protect retinal cells from hypoxia, thus implementing the background to establish potential pharmacological targets based on sst(2) pharmacology.

A strong summer phytoplankton bloom southeast of Vietnam in 2007, a transitional year from El Niño to La Niña

PubMed Central

Chen, Fajin; Han, Guoqi

2018-01-01

Summer upwelling occurs frequently off the southeast Vietnam coast in the western South China Sea (SCS), where summer phytoplankton blooms generally appear during June-August. In this study, we investigate inter-annual variation of Ekman pumping and offshore transport, and its modulation on summer blooms southeast of Vietnam. The results indicate that there are low intensities of summer blooms in El Niño years, under higher sea surface temperatures (SST) and weaker winds. However, a different pattern of monthly chlorophyll a (Chl-a) blooms occurred in summer of 2007, a transitional stage from El Niño to La Niña, with weak (strong) wind and high (low) SST before (after) early July. There is a weak phytoplankton bloom before July 2007 and a strong phytoplankton bloom after July 2007. The abrupt change in the wind intensity may enhance the upwelling associated with Ekman pumping and offshore Ekman transport, bringing more high-nutrient water into the upper layer from the subsurface, and thus leading to an evident Chl-a bloom in the region. PMID:29342148

Warm layer and cool skin corrections for bulk water temperature measurements for air-sea interaction studies

NASA Astrophysics Data System (ADS)

Alappattu, Denny P.; Wang, Qing; Yamaguchi, Ryan; Lind, Richard J.; Reynolds, Mike; Christman, Adam J.

2017-08-01

The sea surface temperature (SST) relevant to air-sea interaction studies is the temperature immediately adjacent to the air, referred to as skin SST. Generally, SST measurements from ships and buoys are taken at depths varies from several centimeters to 5 m below the surface. These measurements, known as bulk SST, can differ from skin SST up to O(1°C). Shipboard bulk and skin SST measurements were made during the Coupled Air-Sea Processes and Electromagnetic ducting Research east coast field campaign (CASPER-East). An Infrared SST Autonomous Radiometer (ISAR) recorded skin SST, while R/V Sharp's Surface Mapping System (SMS) provided bulk SST from 1 m water depth. Since the ISAR is sensitive to sea spray and rain, missing skin SST data occurred in these conditions. However, SMS measurement is less affected by adverse weather and provided continuous bulk SST measurements. It is desirable to correct the bulk SST to obtain a good representation of the skin SST, which is the objective of this research. Bulk-skin SST difference has been examined with respect to meteorological factors associated with cool skin and diurnal warm layers. Strong influences of wind speed, diurnal effects, and net longwave radiation flux on temperature difference are noticed. A three-step scheme is established to correct for wind effect, diurnal variability, and then for dependency on net longwave radiation flux. Scheme is tested and compared to existing correction schemes. This method is able to effectively compensate for multiple factors acting to modify bulk SST measurements over the range of conditions experienced during CASPER-East.

Sea surface salinity and temperature-based predictive modeling of southwestern US winter precipitation: improvements, errors, and potential mechanisms

NASA Astrophysics Data System (ADS)

Liu, T.; Schmitt, R. W.; Li, L.

2017-12-01

Using 69 years of historical data from 1948-2017, we developed a method to globally search for sea surface salinity (SSS) and temperature (SST) predictors of regional terrestrial precipitation. We then applied this method to build an autumn (SON) SSS and SST-based 3-month lead predictive model of winter (DJF) precipitation in southwestern United States. We also find that SSS-only models perform better than SST-only models. We previously used an arbitrary correlation coefficient (r) threshold, |r| > 0.25, to define SSS and SST predictor polygons for best subset regression of southwestern US winter precipitation; from preliminary sensitivity tests, we find that |r| > 0.18 yields the best models. The observed below-average precipitation (0.69 mm/day) in winter 2015-2016 falls within the 95% confidence interval of the prediction model. However, the model underestimates the anomalous high precipitation (1.78 mm/day) in winter 2016-2017 by more than three-fold. Moisture transport mainly attributed to "pineapple express" atmospheric rivers (ARs) in winter 2016-2017 suggests that the model falls short on a sub-seasonal scale, in which case storms from ARs contribute a significant portion of seasonal terrestrial precipitation. Further, we identify a potential mechanism for long-range SSS and precipitation teleconnections: standing Rossby waves. The heat applied to the atmosphere from anomalous tropical rainfall can generate standing Rossby waves that propagate to higher latitudes. SSS anomalies may be indicative of anomalous tropical rainfall, and by extension, standing Rossby waves that provide the long-range teleconnections.

The Aqua-planet Experiment (APE): Response to Changed Meridional SST Profile

NASA Technical Reports Server (NTRS)

Williamson, David L.; Blackburn, Michael; Nakajima, Kensuke; Ohfuchi, Wataru; Takahashi, Yoshiyuki O.; Hayashi, Yoshi-Yuki; Nakamura, Hisashi; Ishiwatari, Masaki; Mcgregor, John L.; Borth, Hartmut;

Suitability of satellite derived and gridded sea surface temperature data sets for calibrating high-resolution marine proxy records

NASA Astrophysics Data System (ADS)

Ouellette, G., Jr.; DeLong, K. L.

2016-02-01

High-resolution proxy records of sea surface temperature (SST) are increasingly being produced using trace element and isotope variability within the skeletal materials of marine organisms such as corals, mollusks, sclerosponges, and coralline algae. Translating the geochemical variations within these organisms into records of SST requires calibration with SST observations using linear regression methods, preferably with in situ SST records that span several years. However, locations with such records are sparse; therefore, calibration is often accomplished using gridded SST data products such as the Hadley Center's HADSST (5º) and interpolated HADISST (1º) data sets, NOAA's extended reconstructed SST data set (ERSST; 2º), optimum interpolation SST (OISST; 1º), and Kaplan SST data sets (5º). From these data products, the SST used for proxy calibration is obtained for a single grid cell that includes the proxy's study site. The gridded data sets are based on the International Comprehensive Ocean-Atmosphere Data Set (ICOADS) and each uses different methods of interpolation to produce the globally and temporally complete data products except for HadSST, which is not interpolated but quality controlled. This study compares SST for a single site from these gridded data products with a high-resolution satellite-based SST data set from NOAA (Pathfinder; 4 km) with in situ SST data and coral Sr/Ca variability for our study site in Haiti to assess differences between these SST records with a focus on seasonal variability. Our results indicate substantial differences in the seasonal variability captured for the same site among these data sets on the order of 1-3°C. This analysis suggests that of the data products, high-resolution satellite SST best captured seasonal variability at the study site. Unfortunately, satellite SST records are limited to the past few decades. If satellite SST are to be used to calibrate proxy records, collecting modern, living samples is desirable.

Endothelin-Converting Enzyme-1 Degrades Internalized Somatostatin-14

PubMed Central

Roosterman, Dirk; Kempkes, Cordula; Cottrell, Graeme S.; Padilla, Benjamin E.; Bunnett, Nigel W.; Turck, Christoph W.; Steinhoff, Martin

2008-01-01

Agonist-induced internalization of somatostatin receptors (ssts) determines subsequent cellular responsiveness to peptide agonists and influences sst receptor scintigraphy. To investigate sst2A trafficking, rat sst2A tagged with epitope was expressed in human embryonic kidney cells and tracked by antibody labeling. Confocal microscopical analysis revealed that stimulation with sst and octreotide induced internalization of sst2A. Internalized sst2A remained sequestrated within early endosomes, and 60 min after stimulation, internalized sst2A still colocalized with β-arrestin1-enhanced green fluorescence protein (EGFP), endothelin-converting enzyme-1 (ECE-1), and rab5a. Internalized 125I-Tyr11-SST-14 was rapidly hydrolyzed by endosomal endopeptidases, with radioactive metabolites being released from the cell. Internalized 125I-Tyr1-octreotide accumulated as an intact peptide and was released from the cell as an intact peptide ligand. We have identified ECE-1 as one of the endopeptidases responsible for inactivation of internalized SST-14. ECE-1-mediated cleavage of SST-14 was inhibited by the specific ECE-1 inhibitor, SM-19712, and by preventing acidification of endosomes using bafilomycin A1. ECE-1 cleaved SST-14 but not octreotide in an acidic environment. The metallopeptidases angiotensin-1 converting enzyme and ECE-2 did not hydrolyze SST-14 or octreotide. Our results show for the first time that stimulation with SST-14 and octreotide induced sequestration of sst2A into early endosomes and that endocytosed SST-14 is degraded by endopeptidases located in early endosomes. Furthermore, octreotide was not degraded by endosomal peptidases and was released as an intact peptide. This mechanism may explain functional differences between octreotide and SST-14 after sst2A stimulation. Moreover, further investigation of endopeptidase-regulated trafficking of neuropeptides may result in novel concepts of neuropeptide receptor inactivation in cancer diagnosis. PMID:18276747

Roles of Hippocampal Somatostatin Receptor Subtypes in Stress Response and Emotionality.

PubMed

Prévôt, Thomas D; Gastambide, François; Viollet, Cécile; Henkous, Nadia; Martel, Guillaume; Epelbaum, Jacques; Béracochéa, Daniel; Guillou, Jean-Louis

2017-07-01

Altered brain somatostatin functions recently appeared as key elements for the pathogenesis of stress-related neuropsychiatric disorders. The hippocampus exerts an inhibitory feedback on stress but the mechanisms involved remain unclear. We investigated herein the role of hippocampal somatostatin receptor subtypes in both stress response and behavioral emotionality using C57BL/6, wild type and sst 2 or sst 4 knockout mice. Inhibitory effects of hippocampal infusions of somatostatin agonists on stress-induced hypothalamo-pituitary-adrenal axis (HPA) activity were tested by monitoring peripheral blood and local hippocampus corticosterone levels, the latter by using microdialysis. Anxiolytic and antidepressant-like effects were determined in the elevated-plus maze, open field, forced swimming, and stress-sensitive beam walking tests. Hippocampal injections of somatostatin analogs and sst 2 or sst 4, but not sst 1 or sst 3 receptor agonists produced rapid and sustained inhibition of HPA axis. sst 2 agonists selectively produced anxiolytic-like behaviors whereas both sst 2 and sst 4 agonists had antidepressant-like effects. Consistent with these findings, high corticosterone levels and anxiety were found in sst 2 KO mice and depressive-like behaviors observed in both sst 2 KO and sst 4 KO strains. Both hippocampal sst 2 and sst 4 receptors selectively inhibit stress-induced HPA axis activation but mediate anxiolytic and antidepressive effects through distinct mechanisms. Such results are to be accounted for in development of pathway-specific somatostatin receptor agents in the treatment of hypercortisolism (Cushing's disease) and stress-related neuropsychiatric disorders.

Merging of multi-temporal SST data at South China Sea

NASA Astrophysics Data System (ADS)

Ng, H. G.; MatJafri, M. Z.; Abdullah, K.; Lim, H. S.

2008-10-01

The sea surface temperature (SST) mapping could be performed with a wide spatial and temporal extent in a reasonable time limit. The space-borne sensor of AVHRR was widely used for the purpose. However, the current SST retrieval techniques for infrared channels were limited only for the cloud-free area, because the electromagnetic waves in the infrared wavelengths could not penetrate the cloud. Therefore, the SST availability was low for the single image. To overcome this problem, we studied to produce the composite of three day's SST map. The diurnal changes of SST data are quite stable through a short period of time if no abrupt natural disaster occurrence. Therefore, the SST data of three consecutive days with nearly coincident daily time were merged in order to create a three day's composite SST data. The composite image could increase the SST availability. In this study, we acquired the level 1b AVHRR (Advanced Very High Resolution Radiometer) images from Malaysia Center of Remote Sensing (MACRES). The images were first preprocessed and the cloud and land areas were masked. We made some modifications on the technique of obtaining the threshold value for cloud masking. The SST was estimated by using the day split MCSST algorithm. The cloud free water pixels availability were computed and compared. The mean of SST for three day's composite data were calculated and a SST map was generated. The cloud free water pixels availability were computed and compared. The SST data availability was increased by merging the SST data.

Octreotide and pasireotide (dis)similarly inhibit pituitary tumor cells in vitro.

PubMed

Ibáñez-Costa, Alejandro; Rivero-Cortés, Esther; Vázquez-Borrego, Mari C; Gahete, Manuel D; Jiménez-Reina, Luis; Venegas-Moreno, Eva; de la Riva, Andrés; Arráez, Miguel Ángel; González-Molero, Inmaculada; Schmid, Herbert A; Maraver-Selfa, Silvia; Gavilán-Villarejo, Inmaculada; García-Arnés, Juan Antonio; Japón, Miguel A; Soto-Moreno, Alfonso; Gálvez, María A; Luque, Raúl M; Castaño, Justo P

2016-11-01

Somatostatin analogs (SSA) are the mainstay of pharmacological treatment for pituitary adenomas. However, some patients escape from therapy with octreotide, a somatostatin receptor 2 (sst2)-preferring SSA, and pasireotide, a novel multi-sst-preferring SSA, may help to overcome this problem. It has been proposed that correspondence between sst1-sst5 expression pattern and SSA-binding profile could predict patient's response. To explore the cellular/molecular features associated with octreotide/pasireotide response, we performed a parallel comparison of their in vitro effects, evaluating sst1-sst5 expression, intracellular Ca 2+ signaling ([Ca 2+ ] i ), hormone secretion and cell viability, in a series of 85 pituitary samples. Somatotropinomas expressed sst5>sst2, yet octreotide reduced [Ca 2+ ] i more efficiently than pasireotide, while both SSA similarly decreased growth hormone release/expression and viability. Corticotropinomas predominantly expressed sst5, but displayed limited response to pasireotide, while octreotide reduced functional endpoints. Non-functioning adenomas preferentially expressed sst3 but, surprisingly, both SSA increased cell viability. Prolactinomas mainly expressed sst1 but were virtually unresponsive to SSA. Finally, both SSA decreased [Ca 2+ ] i in normal pituitaries. In conclusion, both SSA act in vitro on pituitary adenomas exerting both similar and distinct effects; however, no evident correspondence was found with the sst1-sst5 profile. Thus, it seems plausible that additional factors, besides the simple abundance of a given sst, critically influence the SSA response. © 2016 Society for Endocrinology.

A Regulation of Tropical Climate by Radiative Cooling as Simulated in a Cumulus Ensemble Model

NASA Technical Reports Server (NTRS)

Sui, Chung-Hsiung; Lau, K.-M.; Li, X.; Chou, M.-D.; Einaudi, Franco (Technical Monitor)

2000-01-01

Responses of tropical atmosphere to low-boundary forcing are investigated in a 2-D cumulus ensemble model (CEM) with an imposed warm-pool and cold-pool SST contrast (deltaSST). The domain-mean vertical motion is constrained to produce heat sink and moisture source as in the observed tropical climate. In a series of experiments, the warm pool SST is specified at different values while the cold pool SST is specified at 26 C. The strength of the circulation increases with increasing deltaSST until deltaSST reaches 3.5 C, and remains unchanged as deltaSST exceeds 3.5 C. The regulation of tropical convection by zonal SST gradient is constrained by the radiative cooling over the cold pool. For deltaSST less than 3.5 C, an enhanced subsidence warming is balanced by a reduced condensation heating over the cold pool. For deltaSST greater than 3.5 C, the subsidence regime expands over the entire cold pool where no condensation heating exist so that a further enhanced subsidence warming can no longer be sustained. The above regulation mechanism is also evident in the change of energy at the top of the atmosphere (TOA) that is dominated by cloud and water vapor greenhouse effect (c (sub LW)) and G (sub clear). The change in shortwave radiation at TOA is largely cancelled between the warm pool and cold pool, likely due to the same imposed vertical motion in our experiments. For deltaSST less than 3.5 C, an increase of deltaSST is associated with a large increase in c (sub Lw) due to increased total clouds in response to enhanced SST-induced circulation. For deltaSST greater than 3.5 C, clouds over the warm pool decrease with increasing SST, and the change in c (sub LW) is much smaller. In both dSST regimes, the change in CLW is larger than the change in G(sub clear) which is slightly negative. However, in the case of uniform warming (deltaSST=0), DeltaG(sub clear), is positive, approximately 5 W per square meters per degree change of SST.

Evaluation of a school-based educational program to prevent adolescents’ problem behaviors

PubMed Central

Eslami, Ahmad Ali; Ghofranipour, Fazlollah; Bonab, Bagher Ghobari; Zadeh, Davood Shojaei; Shokravi, Farkhondeh Amin; Tabatabaie, Mahmoud Ghazi

2015-01-01

Background: Many researchers believe that adolescents’ problem behaviors are indicators of a deficiency in social skills. This study was aimed to evaluate the effectiveness of a prevention program on reducing problem behaviors in male adolescents. Materials and Methods: In a preposttest design with randomized control group, 49 students received social skills training (SST). Follow-up assessment of outcomes took place 5 months post baseline. The SST program was administered over the course of 10 weeks (10 sessions of 1 h). The main tools were multiple problem behaviors index (MPBI) and Social Skills Rating System – student form (SSRS-S). The control group (57 students) did not receive any intervention. Intervention effects were evaluated with t-test, univariate ANCOVA, and repeated measures ANOVA. Results: Significant difference between groups founded on SSRS at posttest (t = 2.5, P = 0.014) by univariate ANCOVA. In addition, the findings indicated that variation trend of mean scores of SSRS in the intervention group was significant (F = 225.3, P < 0.0001). The intervention group reported Lower levels of MPBI at posttest and follow-up compared to the control group. Significant difference between the two groups did not achieved on MPBI scores in the posttest after adjusting for the pretest scores; however, this difference was significant at the follow up (F = 5.3, P = 0.020). Conclusion: The results suggest that SST was effective in improving social competence and preventing problem behaviors among male adolescent. Future researches must be examined the role of peer and family. PMID:25884000

CFS Forecast Verification

Science.gov Websites

history of Nino3.4 SST anomalies of individual forecasts Forecast anomalies Target season Nino SST Global SST Global Prec Global T2m US Prec US T2m US SM z200 NDJ 2004/2005 Nino SST Global SST Global Prec Global T2m US Prec US T2m US SM z200 DJF 2005 Nino SST Global SST Global Prec Global T2m US Prec US T2m

Differential plastic changes in synthesis and binding in the mouse somatostatin system after electroconvulsive stimulation.

PubMed

Olesen, Mikkel Vestergaard; Gøtzsche, Casper René; Christiansen, Søren Hofman; Woldbye, David Paul Drucker

2018-03-21

Electroconvulsive therapy (ECT) is regularly used to treat patients with severe major depression, but the mechanisms underlying the beneficial effects remain uncertain. Electroconvulsive stimulation (ECS) regulates diverse neurotransmitter systems and induces anticonvulsant effects, properties implicated in mediating therapeutic effects of ECT. Somatostatin (SST) is a candidate for mediating these effects because it is upregulated by ECS and exerts seizure-suppressant effects. However, little is known about how ECS might affect the SST receptor system. The present study examined effects of single and repeated ECS on the synthesis of SST receptors (SSTR1-4) and SST, and SST receptor binding ([125I]LTT-SST28) in mouse hippocampal regions and piriform/parietal cortices. A complex pattern of plastic changes was observed. In the dentate gyrus, SST and SSTR1 expression and the number of hilar SST immunoreactive cells were significantly increased at 1 week after repeated ECS while SSTR2 expression was downregulated by single ECS, and SSTR3 mRNA and SST binding were elevated 24 h after repeated ECS. In hippocampal CA1 and parietal/piriform cortices, we found elevated SST mRNA levels 1 week after repeated ECS and elevated SST binding after single ECS and 24 h after repeated ECS. In hippocampal CA3, repeated ECS increased SST expression 1 week after and SST binding 24 h after. In the parietal cortex, SSTR2 mRNA expression was downregulated after single ECS while SSTR4 mRNA expression was upregulated 24 h after repeated ECS. Considering the known anticonvulsant effects of SST, it is likely that these ECS-induced neuroplastic changes in the SST system could participate in modulating neuronal excitability and potentially contribute to therapeutic effects of ECT.

Somatostatin type-2 receptor activation inhibits glutamate release and prevents status epilepticus

PubMed Central

Kozhemyakin, Maxim; Rajasekaran, Karthik; Todorovic, Marko S.; Kowalski, Samuel L.; Balint, Corinne; Kapur, Jaideep

2013-01-01

Summary Newer therapies are needed for the treatment of status epilepticus (SE) refractory to benzodiazepines. Enhanced glutamatergic neurotransmission leads to SE, and AMPA receptors are modified during SE. Reducing glutamate release during SE is a potential approach to terminate SE. The neuropeptide somatostatin (SST) is proposed to diminish presynaptic glutamate release by activating SST type-2 receptors (SST2R). SST exerts an anticonvulsant action in some experimental models of seizures. Here, we investigated the mechanism of action of SST on excitatory synaptic transmission at the Schaffer collateral-CA1 synapses and the ability of SST to treat SE in rats using patch-clamp electrophysiology and video-EEG monitoring of seizures. SST reduced action potential-dependent EPSCs (sEPSCs) at Schaffer collateral-CA1 synapses at concentrations up to 1 μM; higher concentrations had no effect or increased the sEPSC frequency. SST also prevented paired-pulse facilitation of evoked EPSCs and did not alter action-potential-independent miniature EPSCs (mEPSCs). The effect of SST on EPSCs was inhibited by the SST2R antagonist cyanamid-154806 and was mimicked by the SST2R agonists, octreotide and lanreotide. Both SST and octreotide reduced the firing rate of CA1 pyramidal neurons. Intraventricular administration of SST, within a range of doses, either prevented or attenuated pilocarpine-induced SE or delayed the median time to the first grade 5 seizure by 11 min. Similarly, octreotide or lanreotide prevented or attenuated SE in more than 65% of animals. Compared to the pilocarpine model, octreotide was highly potent in preventing or attenuating continuous hippocampal stimulation-induced SE in all animals within 60 min of SE onset. Our results demonstrate that SST, through the activation of SST2Rs, diminishes presynaptic glutamate release and attenuates SE. PMID:23473742

Assessment of chlorophyll variability along the northwestern coast of Iberian Peninsula

NASA Astrophysics Data System (ADS)

Picado, A.; Alvarez, I.; Vaz, N.; Varela, R.; Gomez-Gesteira, M.; Dias, J. M.

2014-10-01

The northwestern coast of the Iberian Peninsula is characterized by a high primary production mainly supported by coastal upwelling, creating an extraordinary commercial interest for fisheries and aquaculture. Considering chlorophyll-a (Chl-a) as an indicator of primary production, its spatio-temporal variability was researched in this study in the surface water of this upwelling region from 1998 to 2007. Satellite derived Chl-a, Sea Surface Temperature (SST) and Ekman transport data as well as the inflow of the main rivers discharging into the study area were used to investigate the origin of the Chl-a concentration. Empirical Orthogonal Function (EOF) analysis of weekly Chl-a images was performed, as well as correlation analysis between Chl-a concentration, Ekman transport and river discharge. EOF results suggest that the highest Chl-a concentration occurs near the coast up to 60 km offshore. The interannual variability of Chl-a, SST and Ekman transport was also studied considering summer and winter months. Generally, 2005, 2006 and 2007 were the most productive years during the summer months with high Chl-a concentrations along the coast associated to the strong upwelling conditions observed. Otherwise, 1998 seemed to be the most productive year during winter. The absence of upwelling favorable conditions together with localized low SST and considerable discharges, suggests that the high Chl-a concentrations observed during this period are mainly due to the entrance of nutrients through river runoff. However, in winter, high concentrations of colored dissolved organic matter (CDOM), associated with river runoff, are present in the ocean surface, leading to an erroneous strong signal of the satellite. During winter correlations of 0.58 and 0.49 were found between Chl-a concentration and Douro and Minho discharges, respectively, evidencing that high Chl-a concentration was related with river runoff. Otherwise, during summer, Chl-a and Ekman transport exhibited a correlation of - 0.38 indicating that high Chl-a is associated to upwelling events. In summary, it was found that the spatio-temporal variability of Chl-a along the northwestern coast of Iberian Peninsula exhibited the clear influence of upwelling events during summer. Conversely, the variability during winter was mainly due to entrance of nutrients through the rivers discharge which flow into the area.

Application of individual foraminifera Mg/Ca and δ18O analyses for paleoceanographic reconstructions in the Bay of Bengal and other active depositional environments

NASA Astrophysics Data System (ADS)

Fritz-Endres, T.; Dekens, P.; Fehrenbacher, J. S.; Spero, H. J.; Stine, A.

2017-12-01

Paleoceanographic research traditionally focuses on regions where sediment deposition is minimally affected by transport. However, sediment fans near tectonically active regions provide an opportunity to link oceanographic climate to terrestrial processes. Sediment cores recovered during IODP Expedition 354 in the Bay of Bengal include hemipelagic sections that record the history of tectonic uplift and the development of the Indian Monsoon through the last 10 Ma. Although these cores provide a unique opportunity to link marine and terrestrial climate, the complex depositional environment requires that the source of foraminifera is carefully considered before using these proxies to reconstruct oceanographic conditions. Foraminifera in Bengal Fan sediments may have been transported via turbidity currents from the northern Bay of Bengal, where the seasonal variability of SST and SSS is larger compared to the southern Bay of Bengal. We measured single Globigerinoides sacculifer Mg/Ca and δ18O from mudline samples of IODP Site U1454 (8.4°N, 85.5°E, 3721 m water depth) near the modern active channel and Site U1449 (8.4°N, 88.7°E, 3653 m water depth) far from channel activity. We compare these sites to single G. sacculifer from the core-top sample of Site 342KL (20.6°N, 90.1°E, 1256 m water depth) located on the continental shelf. Each foraminifera lives 2-4 weeks and the distribution of 60 to 80 data points reflects the seasonal range of SST and SSS at the location where the foraminifera calcified. Measurements in foraminifera from Site U1449 (away from active channel) are statistically different from the site in the northern Bay of Bengal and more consistent with local conditions. Conversely, foraminifera from the site near the active channel reflect a combined signal of local conditions recorded from the site far from channel activity and those recorded from the continental shelf. This suggests a portion of foraminifera from the active channel site have been transported from the northern Bay of Bengal. Our data show that foraminifera can be used to reconstruct SST and δ18O in this complex depositional environment, but caution must be taken when the down-core lithology indicates turbidites and possible sediment transport

Interbasin Differences in the Relationship between SST and Tropical Cyclone Intensification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Foltz, Gregory R.; Balaguru, Karthik; Hagos, Samson

Sea surface temperature (SST) is one of the most important parameters for tropical cyclone (TC) intensification. Here it is shown that the impact of SST on TC intensification varies considerably from basin to basin, with SST explaining less than 3% of the variance in TC intensification rates in the Atlantic, 10% in the western North Pacific, and 17% in the eastern Pacific. Two main factors are shown to be responsible for these inter-basin differences. First, variability of SST along TCs’ tracks is considerably lower in the Atlantic. This is due to smaller horizontal SST gradients in the Atlantic compared tomore » the eastern Pacific and stronger damping of pre-storm SST’s contribution to TC intensification by the storm-induced cold SST wake in the Atlantic. The damping occurs because SST tends to vary in phase with TC- induced SST cooling: in the Gulf of Mexico and northwestern basin where SSTs are highest, TCs’ translation speeds are lowest and therefore their cold wakes are strongest. In addition to this SST effect, a second factor is that SST tends to vary out of phase with vertical wind shear and outflow temperature in the western Pacific, with high SST associated with weak wind shear and a cold upper troposphere. This strengthens the relationship between SST and TC intensification more in the western Pacific than in the eastern Pacific or Atlantic. Combined, these factors explain why pre-storm SST is such a poor predictor of TC intensification in the Atlantic compared to the eastern and western North Pacific.« less

Aeronautical research in the United States - Challenges for the 1990's

NASA Technical Reports Server (NTRS)

Petersen, Richard H.; Holmes, Bruce J.

1990-01-01

An overview is presented of NASA R&D initiatives in air transportation technologies that will dominate its efforts through the 1990s. These efforts are to be concentrated in (1) advanced subsonic transports with greater fuel economy, passenger capacity, and control effectiveness, whose design will be undertaken with state-of-the-art CFD and CAD/CAM systems; (2) a second-generation SST whose propulsion system will be substantially more fuel-efficient than that of Concorde and have far lower atmospheric emissions; and (3) a hypersonic transport predicated on the results of research into materials, cryogenic fuels, propulsion cycles, and propulsion/airframe aerodynamics integration, which will be undertaken in connection with the X-30 testbed.

Central administration of pansomatostatin agonist ODT8-SST prevents abdominal surgery-induced inhibition of circulating ghrelin, food intake and gastric emptying in rats

PubMed Central

STENGEL, A.; GOEBEL-STENGEL, M.; WANG, L.; LUCKEY, A.; HU, E.; RIVIER, J.; TACHÉ, Y.

2011-01-01

Background Activation of brain somatostatin receptors (sst1-5) with the stable pan-sst1-5 somatostatin agonist, ODT8-SST blocks acute stress and central corticotropin-releasing factor (CRF)-mediated activation of endocrine adrenal sympathetic responses. Brain CRF signaling is involved in delaying gastric emptying (GE) immediately post surgery. We investigated whether activation of brain sst signaling pathways modulates surgical stress-induced inhibition of gastric emptying and food intake. Methods Fasted rats were injected intracisternally (i.c.) with somatostatin agonists and underwent laparotomy and 1-min cecal palpation. GE of a non-nutrient solution and circulating acyl and desacyl ghrelin levels were assessed 50 min post surgery. Food intake was monitored for 24h. Key results The abdominal surgery-induced inhibition of GE (65%), food intake (73% at 2h) and plasma acyl ghrelin levels (67%) was completely prevented by ODT8-SST (1μg/rat, i.c.). The selective sst5 agonist, BIM-23052 prevented surgery-induced delayed GE, whereas selective sst1, sst2 or sst4 agonists had no effect. However, the selective sst2 agonist, S-346-011 (1μg/rat, i.c.) counteracted the abdominal surgery-induced inhibition of acyl ghrelin and food intake but not the delayed GE. The ghrelin receptor antagonist, [D-Lys3]-GHRP-6 (0.93 mg/kg, intraperitoneal, i.p.) blocked i.p. ghrelin-induced increased GE, while not influencing i.c. ODT8-SST-induced prevention of delayed GE and reduced food intake after surgery. Conclusions & Inferences ODT8-SST acts in the brain to prevent surgery-induced delayed GE likely via activating sst5. ODT8-SST and the sst2 agonist prevent the abdominal surgery-induced decrease in food intake and plasma acyl ghrelin indicating dissociation between brain somatostatin signaling involved in preventing surgery-induced suppression of GE and feeding response. PMID:21569179

Agonist-biased trafficking of somatostatin receptor 2A in enteric neurons.

PubMed

Zhao, Peishen; Canals, Meritxell; Murphy, Jane E; Klingler, Diana; Eriksson, Emily M; Pelayo, Juan-Carlos; Hardt, Markus; Bunnett, Nigel W; Poole, Daniel P

2013-09-06

Somatostatin (SST) 14 and SST 28 activate somatostatin 2A receptors (SSTR2A) on enteric neurons to control gut functions. SST analogs are treatments of neuroendocrine and bleeding disorders, cancer, and diarrhea, with gastrointestinal side effects of constipation, abdominal pain, and nausea. How endogenous agonists and drugs differentially regulate neuronal SSTR2A is unexplored. We evaluated SSTR2A trafficking in murine myenteric neurons and neuroendocrine AtT-20 cells by microscopy and determined whether agonist degradation by endosomal endothelin-converting enzyme 1 (ECE-1) controls SSTR2A trafficking and association with β-arrestins, key regulators of receptors. SST-14, SST-28, and peptide analogs (octreotide, lanreotide, and vapreotide) stimulated clathrin- and dynamin-mediated internalization of SSTR2A, which colocalized with ECE-1 in endosomes and the Golgi. After incubation with SST-14, SSTR2A recycled to the plasma membrane, which required active ECE-1 and an intact Golgi. SSTR2A activated by SST-28, octreotide, lanreotide, or vapreotide was retained within the Golgi and did not recycle. Although ECE-1 rapidly degraded SST-14, SST-28 was resistant to degradation, and ECE-1 did not degrade SST analogs. SST-14 and SST-28 induced transient interactions between SSTR2A and β-arrestins that were stabilized by an ECE-1 inhibitor. Octreotide induced sustained SSTR2A/β-arrestin interactions that were not regulated by ECE-1. Thus, when activated by SST-14, SSTR2A internalizes and recycles via the Golgi, which requires ECE-1 degradation of SST-14 and receptor dissociation from β-arrestins. After activation by ECE-1-resistant SST-28 and analogs, SSTR2A remains in endosomes because of sustained β-arrestin interactions. Therapeutic SST analogs are ECE-1-resistant and retain SSTR2A in endosomes, which may explain their long-lasting actions.

Agonist-biased Trafficking of Somatostatin Receptor 2A in Enteric Neurons*

PubMed Central

Zhao, Peishen; Canals, Meritxell; Murphy, Jane E.; Klingler, Diana; Eriksson, Emily M.; Pelayo, Juan-Carlos; Hardt, Markus; Bunnett, Nigel W.; Poole, Daniel P.

2013-01-01

Somatostatin (SST) 14 and SST 28 activate somatostatin 2A receptors (SSTR2A) on enteric neurons to control gut functions. SST analogs are treatments of neuroendocrine and bleeding disorders, cancer, and diarrhea, with gastrointestinal side effects of constipation, abdominal pain, and nausea. How endogenous agonists and drugs differentially regulate neuronal SSTR2A is unexplored. We evaluated SSTR2A trafficking in murine myenteric neurons and neuroendocrine AtT-20 cells by microscopy and determined whether agonist degradation by endosomal endothelin-converting enzyme 1 (ECE-1) controls SSTR2A trafficking and association with β-arrestins, key regulators of receptors. SST-14, SST-28, and peptide analogs (octreotide, lanreotide, and vapreotide) stimulated clathrin- and dynamin-mediated internalization of SSTR2A, which colocalized with ECE-1 in endosomes and the Golgi. After incubation with SST-14, SSTR2A recycled to the plasma membrane, which required active ECE-1 and an intact Golgi. SSTR2A activated by SST-28, octreotide, lanreotide, or vapreotide was retained within the Golgi and did not recycle. Although ECE-1 rapidly degraded SST-14, SST-28 was resistant to degradation, and ECE-1 did not degrade SST analogs. SST-14 and SST-28 induced transient interactions between SSTR2A and β-arrestins that were stabilized by an ECE-1 inhibitor. Octreotide induced sustained SSTR2A/β-arrestin interactions that were not regulated by ECE-1. Thus, when activated by SST-14, SSTR2A internalizes and recycles via the Golgi, which requires ECE-1 degradation of SST-14 and receptor dissociation from β-arrestins. After activation by ECE-1-resistant SST-28 and analogs, SSTR2A remains in endosomes because of sustained β-arrestin interactions. Therapeutic SST analogs are ECE-1-resistant and retain SSTR2A in endosomes, which may explain their long-lasting actions. PMID:23913690

Numerical Simulations For the F-16XL Aircraft Configuration

NASA Technical Reports Server (NTRS)

Elmiligui, Alaa A.; Abdol-Hamid, Khaled; Cavallo, Peter A.; Parlette, Edward B.

2014-01-01

Numerical simulations of flow around the F-16XL are presented as a contribution to the Cranked Arrow Wing Aerodynamic Project International II (CAWAPI-II). The NASA Tetrahedral Unstructured Software System (TetrUSS) is used to perform numerical simulations. This CFD suite, developed and maintained by NASA Langley Research Center, includes an unstructured grid generation program called VGRID, a postprocessor named POSTGRID, and the flow solver USM3D. The CRISP CFD package is utilized to provide error estimates and grid adaption for verification of USM3D results. A subsonic high angle-of-attack case flight condition (FC) 25 is computed and analyzed. Three turbulence models are used in the calculations: the one-equation Spalart-Allmaras (SA), the two-equation shear stress transport (SST) and the ke turbulence models. Computational results, and surface static pressure profiles are presented and compared with flight data. Solution verification is performed using formal grid refinement studies, the solution of Error Transport Equations, and adaptive mesh refinement. The current study shows that the USM3D solver coupled with CRISP CFD can be used in an engineering environment in predicting vortex-flow physics on a complex configuration at flight Reynolds numbers.

Validation of the Version 1 NOAA/NASA Pathfinder Sea Surface Temperature Data Set

NASA Technical Reports Server (NTRS)

Smith, Elizabeth A.

1998-01-01

A high-resolution, global satellite-derived sea surface temperature (SST) data set called Pathfinder, from the Advanced Very High Resolution Radiometer (AVHRR) aboard the NOAA Polar Orbiters, is available from the Jet Propulsion Laboratory Physical Oceanography Distributed Active Archive Center (JPL PO.DAAC). Suitable for research as well as education, the Pathfinder SST data set is a result of a collaboration between the National Oceanographic and Atmospheric Administration (NOAA), the National Aeronautics and Space Administration (NASA) and investigators at several universities. NOAA and NASA are the sponsors of the Pathfinder Program, which takes advantage of currently archived Earth science data from satellites. Where necessary, satellite sensors have been intercalibrated, algorithms improved and processing procedures revised, in order to produce long time-series, global measurements of ocean, land and atmospheric properties necessary for climate research. Many Pathfinder data sets are available to researchers now, nearly a decade before the first launch of NASA's Earth Observing System (EOS). The lessons learned from the Pathfinder programs will facilitate the processing and management of terabytes of data from EOS. The Oceans component of Pathfinder has undertaken to reprocess all Global Area Coverage (GAC) data acquired by the 5-channel AVHRRs since 1981. The resultant data products are consistent and stably calibrated [Rao, 1993a, Rao, 1993b, Brown et al., 1993], Earth-gridded SST fields at a variety of spatial and temporal resolutions.

Peptide receptor targeting in cancer: the somatostatin paradigm.

PubMed

Barbieri, Federica; Bajetto, Adriana; Pattarozzi, Alessandra; Gatti, Monica; Würth, Roberto; Thellung, Stefano; Corsaro, Alessandro; Villa, Valentina; Nizzari, Mario; Florio, Tullio

2013-01-01

Peptide receptors involved in pathophysiological processes represent promising therapeutic targets. Neuropeptide somatostatin (SST) is produced by specialized cells in a large number of human organs and tissues. SST primarily acts as inhibitor of endocrine and exocrine secretion via the activation of five G-protein-coupled receptors, named sst1-5, while in central nervous system, SST acts as a neurotransmitter/neuromodulator, regulating locomotory and cognitive functions. Critical points of SST/SST receptor biology, such as signaling pathways of individual receptor subtypes, homo- and heterodimerization, trafficking, and cross-talk with growth factor receptors, have been extensively studied, although functions associated with several pathological conditions, including cancer, are still not completely unraveled. Importantly, SST exerts antiproliferative and antiangiogenic effects on cancer cells in vitro, and on experimental tumors in vivo. Moreover, SST agonists are clinically effective as antitumor agents for pituitary adenomas and gastro-pancreatic neuroendocrine tumors. However, SST receptors being expressed by tumor cells of various tumor histotypes, their pharmacological use is potentially extendible to other cancer types, although to date no significant results have been obtained. In this paper the most recent findings on the expression and functional roles of SST and SST receptors in tumor cells are discussed.

Spatio-temporal variability of upwelling along the southwest coast of India based on satellite observations

NASA Astrophysics Data System (ADS)

Jayaram, Chiranjivi; Kumar, P. K. Dinesh

2018-03-01

Upwelling phenomenon along the eastern boundaries of global ocean has received greater attention in the recent times due to its environmental and economic significance in the global warming and the scenario of changing climate as opined by IPCC AR5. In this context, the availabile satellite data on sea surface winds, sea surface temperature (SST), sea level anomaly (SLA) and chlorophyll-a concentration (Chl-a), for the period 1981-2016 were analyzed to identify the coastal upwelling pattern in the Southeastern Arabian Sea (SEAS). Synergistic approach, using winds, SST, SLA and Chl-a revealed that strong upwelling was prevailing between 8°N and 12°N. During the study period, geographical differences existed in the peak values of upwelling favorable conditions considered for study. Analysis of the alongshore winds which are conducive for upwelling were observed to be curtailed towards the northern part of the study region between 2005 and 2010. Also, the strength of upwelling reduced during the strong ENSO years of 1997 and 2015. Linear regression based trend analysis of upwelling indices like Ekman transport, SST and chlorophyll along the coast, during the upwelling period, revealed slight increase in the strength towards the southern region while it decreased to the north during the study period.

Rising Mediterranean Sea Surface Temperatures Amplify Extreme Summer Precipitation in Central Europe

NASA Astrophysics Data System (ADS)

Volosciuk, Claudia; Maraun, Douglas; Semenov, Vladimir A.; Tilinina, Natalia; Gulev, Sergey K.; Latif, Mojib

2016-08-01

The beginning of the 21st century was marked by a number of severe summer floods in Central Europe associated with extreme precipitation (e.g., Elbe 2002, Oder 2010 and Danube 2013). Extratropical storms, known as Vb-cyclones, cause summer extreme precipitation events over Central Europe and can thus lead to such floodings. Vb-cyclones develop over the Mediterranean Sea, which itself strongly warmed during recent decades. Here we investigate the influence of increased Mediterranean Sea surface temperature (SST) on extreme precipitation events in Central Europe. To this end, we carry out atmosphere model simulations forced by average Mediterranean SSTs during 1970-1999 and 2000-2012. Extreme precipitation events occurring on average every 20 summers in the warmer-SST-simulation (2000-2012) amplify along the Vb-cyclone track compared to those in the colder-SST-simulation (1970-1999), on average by 17% in Central Europe. The largest increase is located southeast of maximum precipitation for both simulated heavy events and historical Vb-events. The responsible physical mechanism is increased evaporation from and enhanced atmospheric moisture content over the Mediterranean Sea. The excess in precipitable water is transported from the Mediterranean Sea to Central Europe causing stronger precipitation extremes over that region. Our findings suggest that Mediterranean Sea surface warming amplifies Central European precipitation extremes.

Wind-driven changes of surface current, temperature, and chlorophyll observed by satellites north of New Guinea

NASA Astrophysics Data System (ADS)

Radenac, Marie-Hélène; Léger, Fabien; Messié, Monique; Dutrieux, Pierre; Menkes, Christophe; Eldin, Gérard

2016-04-01

Satellite observations of wind, sea level and derived currents, sea surface temperature (SST), and chlorophyll are used to expand our understanding of the physical and biological variability of the ocean surface north of New Guinea. Based on scarce cruise and mooring data, previous studies differentiated a trade wind situation (austral winter) when the New Guinea Coastal Current (NGCC) flows northwestward and a northwest monsoon situation (austral summer) when a coastal upwelling develops and the NGCC reverses. This circulation pattern is confirmed by satellite observations, except in Vitiaz Strait where the surface northwestward flow persists. We find that intraseasonal and seasonal time scale variations explain most of the variance north of New Guinea. SST and chlorophyll variabilities are mainly driven by two processes: penetration of Solomon Sea waters and coastal upwelling. In the trade wind situation, the NGCC transports cold Solomon Sea waters through Vitiaz Strait in a narrow vein hugging the coast. Coastal upwelling is generated in westerly wind situations (westerly wind event, northwest monsoon). Highly productive coastal waters are advected toward the equator and, during some westerly wind events, toward the eastern part of the warm pool. During El Niño, coastal upwelling events and northward penetration of Solomon Sea waters combine to influence SST and chlorophyll anomalies.

Ocean-Atmosphere Interaction Over Agulhas Extension Meanders

NASA Technical Reports Server (NTRS)

Liu, W. Timothy; Xie, Xiaosu; Niiler, Pearn P.

2007-01-01

Many years of high-resolution measurements by a number of space-based sensors and from Lagrangian drifters became available recently and are used to examine the persistent atmospheric imprints of the semi-permanent meanders of the Agulhas Extension Current (AEC), where strong surface current and temperature gradients are found. The sea surface temperature (SST) measured by the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) and the chlorophyll concentration measured by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) support the identification of the meanders and related ocean circulation by the drifters. The collocation of high and low magnitudes of equivalent neutral wind (ENW) measured by Quick Scatterometer (QuikSCAT), which is uniquely related to surface stress by definition, illustrates not only the stability dependence of turbulent mixing but also the unique stress measuring capability of the scatterometer. The observed rotation of ENW in opposition to the rotation of the surface current clearly demonstrates that the scatterometer measures stress rather than winds. The clear differences between the distributions of wind and stress and the possible inadequacy of turbulent parameterization affirm the need of surface stress vector measurements, which were not available before the scatterometers. The opposite sign of the stress vorticity to current vorticity implies that the atmosphere spins down the current rotation through momentum transport. Coincident high SST and ENW over the southern extension of the meander enhance evaporation and latent heat flux, which cools the ocean. The atmosphere is found to provide negative feedback to ocean current and temperature gradients. Distribution of ENW convergence implies ascending motion on the downwind side of local SST maxima and descending air on the upwind side and acceleration of surface wind stress over warm water (deceleration over cool water); the convection may escalate the contrast of ENW over warm and cool water set up by the dependence of turbulent mixing on stability; this relation exerts a positive feedback to the ENW-SST relation. The temperature sounding measured by the Atmospheric Infrared Sounder(AIRS) is consistent with the spatial coherence between the cloud-top temperature provided by the International Satellite Cloud Climatology Project (ISCCP) and SST. Thus ocean mesoscale SST anomalies associated with the persistent meanders may have a long-term effect well above the midlatitude atmospheric boundary layer, an observation not addressed in the past.

The Role of SST and Large-Scale Dynamical Motions on the Onset and Shutdown of the Super Greenhouse Effect

NASA Astrophysics Data System (ADS)

O'Brien, T. A.; Kashinath, K.; Collins, W.

2015-12-01

Over warm tropical oceans the increase in greenhouse trapping with increasing SST is faster than that of the surface emission, resulting in a decrease in outgoing longwave radiation at the top of the atmosphere (OLR) when SST increases, also known as the super greenhouse effect (SGE). If SGE is directly linked to SST changes, there are profound implications for positive climate feedbacks in the tropics. However, a number of studies in the last 20 years have provided compelling evidence that the OLR-SST relationship is coincidental rather than causal. These studies suggested that the onset of SGE is dominated by the large-scale dynamics, and that the apparent OLR-SST relationships disappear when individual large-scale regimes are considered. We show that these conclusions are contingent on the quality of the datasets used in the analysis, and that modern satellite observations and reanalyses support a strong relationship between SGE and SST. We find that the SGE occurs across all dynamical regimes, suggesting that this may be related primarily to SST rather than large-scale dynamics. We also find that the discontinuity in the relationship between OLR and SST at high SST (29.5 C), i.e. the shutdown of SGE, also occurs across almost all dynamical regimes, suggesting that this behavior may also be strongly linked to SST. Collectively, these results suggest that the SGE may actually be controlled by SST. Work is ongoing to understand the robustness of this new result to other datasets, to understand whether SST is truly the controlling variable, and to understand the mechanism by which OLR could decrease with increasing SST even under strongly subsiding conditions.

Truncated somatostatin receptor 5 may modulate therapy response to somatostatin analogues--Observations in two patients with acromegaly and severe headache.

PubMed

Marina, Djordje; Burman, Pia; Klose, Marianne; Casar-Borota, Olivera; Luque, Raúl M; Castaño, Justo P; Feldt-Rasmussen, Ulla

2015-10-01

Somatotropinomas have unique "fingerprints" of somatostatin receptor (sst) expression, which are targets in treatment of acromegaly with somatostatin analogues (SSAs). However, a significant expression of sst is not always related to the biochemical response to SSAs. Headache is a common complaint in acromegaly and considered a clinical marker of disease activity. SSAs are reported to have an own analgesic effect, but the sst involved are unknown. We investigated sst expression in two acromegalic patients with severe headache and no biochemical effects of octreotide, but a good response to pasireotide. We searched the literature for determinants of biochemical and analgesic effects of SSAs in somatotropinomas. Case 1 had no biochemical or analgesic effects of octreotide, a semi-selective SSA, but a rapid and significant effect of pasireotide, a pan-SSA. Case 2 demonstrated discordance between analgesic and biochemical effects of octreotide, in that headache disappeared, but without biochemical improvement. In contrast, pasireotide normalized insulin-like growth factor 1. Both adenomas were sparsely granulated and had strong membranous expressions of sst2a in 50-75% and sst5 in 75-100% of tumor cells. The truncated sst5 variant TMD4 (sst5TMD4) showed expression in 20-57% of tumor cells. A poor biochemical response to octreotide may be associated with tumor expression of a truncated sst5 variant, despite abundant sst2a expression, suggesting an influence from variant sst5 on common sst signaling pathways. Furthermore, unrelated analgesic and biochemical effects of SSAs supported a complex pathogenesis of acromegaly-associated headache. Finally, assessment of truncated sst5 in addition to full length sst could be important for a choice of postoperative SSA treatment in somatotropinomas. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Global Drifter Program Currents, Sea Surface Temperature, Atmospheric Pressure and Waves in the World's OceanThe Global Drifter Program Currents, Sea Surface Temperature, Atmospheric Pressure and Waves in the World's Ocean

NASA Astrophysics Data System (ADS)

Centurioni, Luca

2017-04-01

The Global Drifter Program is the principal component of the Global Surface Drifting Buoy Array, a branch of NOAA's Global Ocean Observing System and a scientific project of the Data Buoy Cooperation Panel (DBCP). The DBCP is an international program coordinating the use of autonomous data buoys to observe atmospheric and oceanographic conditions over ocean areas where few other measurements are taken. The Global Drifter Program maintains an array of over 1,250 Lagrangian drifters, reporting in near real-time and designed measure 15 m depth Lagrangian currents, sea surface temperature (SST) and sea level atmospheric pressure (SLP), among others, to fulfill the needs to observe the air-sea interface at temporal and spatial scales adequate to support short to medium-range weather forecasting, ocean state estimates and climate science. This overview talk will discuss the main achievements of the program, the main impacts for satellite SST calibration and validation, for numerical weather prediction, and it will review the main scientific findings based on the use of Lagrangian currents. Finally, we will present new developments in Lagrangian drifter technology, which include special drifters designed to measure sea surface salinity, wind and directional wave spectra. New opportunities for expanding the scope of the Global Drifter Program will be discussed.

Suborbital Holocene Climate Variability over Continental Western Eurasia Coupled with Poleward Heat Transport to the Northeastern Atlantic Ocean

NASA Astrophysics Data System (ADS)

Baker, J. L.; Lachniet, M. S.; Asmerom, Y.; Polyak, V. J.

2016-12-01

The centennial-scale coupling between the Holocene paleoclimate of Eurasia and ocean-atmosphere dynamics in the North Atlantic sector remains weakly understood, due to a paucity of high-resolution data from the continental interior. To investigate these links, we detrended a composite record of stalagmite δ18O from Kinderlinskaya Cave (southern Urals Mountains), which exhibits long-term warming from 11.7 ka to present. The chronologies of two stalagmites were constrained by 29 U-Th dates obtained through MC-ICP-MS analysis. Stable-isotope analysis at 0.5-mm resolution along the growth axes resulted in an average sampling frequency of 12.5 years. Stalagmite δ18O reflects multidecadal changes in the δ18O of winter half-year precipitation, which is highly sensitive to AO/NAO-like shifts in the strength and position of mid-latitude westerlies. Spectral density and wavelet analysis of the detrended record revealed significant periodicities near 2.4 ka, 1.4 ka, and 1.0 ka, which are common in northern hemispheric paleoclimate records and possibly related to solar and oceanic forcing during the Holocene. Coherent hemispheric coupling of continental and oceanic paleoclimate at suborbital timescales is demonstrated by comparison of our record with reconstructions of sea-surface temperature (SST) and meridional flow strength in the North Atlantic sector. Specifically, SST at cores MD-23258 and LO09-14 in the Barents Sea and Reykjanes Ridge, respectively, exhibit opposite phasing during the Holocene, due to alternating strength between the eastern and western branches of the North Atlantic Current, a major component of AMOC. Estimating the SST gradient between these sites as a proxy for poleward heat transport to the northeastern Atlantic Ocean, we find a strong covariance with detrended stalagmite δ18O. This relationship suggests that persistent strengthening (weakening) of wintertime westerlies, analogous to positive (negative) phases of the AO/NAO, was forced by enhanced (reduced) poleward heat transport along the Norwegian Current. Our record complements existing reconstructions of Holocene AO/NAO variability and provides a paleoanalog for the oceanographic response to rapid melting of the Greenland Ice Sheet under modern anthropogenic warming.

Improving a two-equation eddy-viscosity turbulence model to predict the aerodynamic performance of thick wind turbine airfoils

NASA Astrophysics Data System (ADS)

Bangga, Galih; Kusumadewi, Tri; Hutomo, Go; Sabila, Ahmad; Syawitri, Taurista; Setiadi, Herlambang; Faisal, Muhamad; Wiranegara, Raditya; Hendranata, Yongki; Lastomo, Dwi; Putra, Louis; Kristiadi, Stefanus

2018-03-01

Numerical simulations for relatively thick airfoils are carried out in the present studies. An attempt to improve the accuracy of the numerical predictions is done by adjusting the turbulent viscosity of the eddy-viscosity Menter Shear-Stress-Transport (SST) model. The modification involves the addition of a damping factor on the wall-bounded flows incorporating the ratio of the turbulent kinetic energy to its specific dissipation rate for separation detection. The results are compared with available experimental data and CFD simulations using the original Menter SST model. The present model improves the lift polar prediction even though the stall angle is still overestimated. The improvement is caused by the better prediction of separated flow under a strong adverse pressure gradient. The results show that the Reynolds stresses are damped near the wall causing variation of the logarithmic velocity profiles.

The forcing of southwestern Asia teleconnections by low-frequency sea surface temperature variability during boreal winter

USGS Publications Warehouse

Hoell, Andrew; Funk, Christopher C.; Mathew Barlow,

2015-01-01

Southwestern Asia, defined here as the domain bounded by 20°–40°N and 40°–70°E, which includes the nations of Iraq, Iran, Afghanistan, and Pakistan, is a water-stressed and semiarid region that receives roughly 75% of its annual rainfall during November–April. The November–April climate of southwestern Asia is strongly influenced by tropical Indo-Pacific variability on intraseasonal and interannual time scales, much of which can be attributed to sea surface temperature (SST) variations. The influences of lower-frequency SST variability on southwestern Asia climate during November–April Pacific decadal SST (PDSST) variability and the long-term trend in SST (LTSST) is examined. The U.S. Climate Variability and Predictability Program (CLIVAR) Drought Working Group forced global atmospheric climate models with PDSST and LTSST patterns, identified using empirical orthogonal functions, to show the steady atmospheric response to these modes of decadal to multidecadal SST variability. During November–April, LTSST forces an anticyclone over southwestern Asia, which results in reduced precipitation and increases in surface temperature. The precipitation and tropospheric circulation influences of LTSST are corroborated by independent observed precipitation and circulation datasets during 1901–2004. The decadal variations of southwestern Asia precipitation may be forced by PDSST variability, with two of the three models indicating that the cold phase of PDSST forces an anticyclone and precipitation reductions. However, there are intermodel circulation variations to PDSST that influence subregional precipitation patterns over the Middle East, southwestern Asia, and subtropical Asia. Changes in wintertime temperature and precipitation over southwestern Asia forced by LTSST and PDSST imply important changes to the land surface hydrology during the spring and summer.

Impact of warming events on reef-scale temperature variability as captured in two Little Cayman coral Sr/Ca records

NASA Astrophysics Data System (ADS)

von Reumont, J.; Hetzinger, S.; Garbe-Schönberg, D.; Manfrino, C.; Dullo, W.-Chr.

2016-03-01

The rising temperature of the world's oceans is affecting coral reef ecosystems by increasing the frequency and severity of bleaching and mortality events. The susceptibility of corals to temperature stress varies on local and regional scales. Insights into potential controlling parameters are hampered by a lack of long term in situ data in most coral reef environments and sea surface temperature (SST) products often do not resolve reef-scale variations. Here we use 42 years (1970-2012) of coral Sr/Ca data to reconstruct seasonal- to decadal-scale SST variations in two adjacent but distinct reef environments at Little Cayman, Cayman Islands. Our results indicate that two massive Diploria strigosa corals growing in the lagoon and in the fore reef responded differently to past warming events. Coral Sr/Ca data from the shallow lagoon successfully record high summer temperatures confirmed by in situ observations (>33°C). Surprisingly, coral Sr/Ca from the deeper fore reef is strongly affected by thermal stress events, although seasonal temperature extremes and mean SSTs at this site are reduced compared to the lagoon. The shallow lagoon coral showed decadal variations in Sr/Ca, supposedly related to the modulation of lagoonal temperature through varying tidal water exchange, influenced by the 18.6 year lunar nodal cycle. Our results show that reef-scale SST variability can be much larger than suggested by satellite SST measurements. Thus, using coral SST proxy records from different reef zones combined with in situ observations will improve conservation programs that are developed to monitor and predict potential thermal stress on coral reefs.

North American Tropical Cyclone Landfall and SST: A Statistical Model Study

NASA Technical Reports Server (NTRS)

Hall, Timothy; Yonekura, Emmi

2013-01-01

A statistical-stochastic model of the complete life cycle of North Atlantic (NA) tropical cyclones (TCs) is used to examine the relationship between climate and landfall rates along the North American Atlantic and Gulf Coasts. The model draws on archived data of TCs throughout the North Atlantic to estimate landfall rates at high geographic resolution as a function of the ENSO state and one of two different measures of sea surface temperature (SST): 1) SST averaged over the NA subtropics and the hurricane season and 2) this SST relative to the seasonal global subtropical mean SST (termed relSST). Here, the authors focus on SST by holding ENSO to a neutral state. Jackknife uncertainty tests are employed to test the significance of SST and relSST landfall relationships. There are more TC and major hurricane landfalls overall in warm years than cold, using either SST or relSST, primarily due to a basinwide increase in the number of storms. The signal along the coast, however, is complex. Some regions have large and significant sensitivity (e.g., an approximate doubling of annual major hurricane landfall probability on Texas from -2 to +2 standard deviations in relSST), while other regions have no significant sensitivity (e.g., the U.S. mid-Atlantic and Northeast coasts). This geographic structure is due to both shifts in the regions of primary TC genesis and shifts in TC propagation.

Selective agonists of somatostatin receptor subtype 1 or 2 injected peripherally induce antihyperalgesic effect in two models of visceral hypersensitivity in mice

PubMed Central

Mulak, Agata; Larauche, Muriel; Biraud, Mandy; Million, Mulugeta; Rivier, Jean; Taché, Yvette

2014-01-01

Somatostatin interacts with 5 G-protein-coupled receptor (sst1–5). Octreotide, a stable sst2≫3≥5 agonist, octreotide, exerts a visceral anti-hyperalgesic effect in experimental and clinical studies. Little is known on the receptor subtypes involved. We investigated the influence of the stable sst1–5 agonist, ODT8-SST and selective receptor subtype peptide agonists (3 or 10 μg/mouse) injected intraperitoneally (ip) on visceral hypersensitivity in mice induced by repeated noxious colorectal distensions (4 sets of 3 CRD, each at 55 mmHg) or corticotropin-releasing factor receptor 1 agonist, cortagine given between 2 sets of graded CRD (15, 30, 45, and 60 mmHg, 3 times each pressure). The mean visceromotor response (VMR) was assessed using a non-invasive manometry method and values were expressed as percentage of the VMR to the 1st set of CRD baseline or to the 60 mmHg CRD, respectively. ODT8-SST (10 μg) and the sst2 agonist, S-346-011 (3 and 10 μg) prevented mechanically-induced visceral hypersensitivity in the 3 sets of CRD, the sst1 agonist (10 μg) blocked only the 2nd set and showed a trend at 3 μg while the sst4 agonist had no effect. The selective sst2 antagonist, S-406-028 blocked the sst2 agonist but not the sst1 agonist effect. The sst1 agonist (3 and 10 μg) prevented cortagine-induced hypersensitivity to CRD at each pressure while the sst2 agonist at 10 μg reduced it. These data indicate that in addition to sst2, the sst1 agonist may provide a novel promising target to alleviate visceral hypersensitivity induced by mechanoreceptor sensitization and more prominently, stress-related visceral nociceptive sensitization. PMID:25451334

Selective agonists of somatostatin receptor subtype 1 or 2 injected peripherally induce antihyperalgesic effect in two models of visceral hypersensitivity in mice.

PubMed

Mulak, Agata; Larauche, Muriel; Biraud, Mandy; Million, Mulugeta; Rivier, Jean; Taché, Yvette

2015-01-01

Somatostatin interacts with five G-protein-coupled receptor (sst1-5). Octreotide, a stable sst2≫3≥5 agonist, exerts a visceral anti-hyperalgesic effect in experimental and clinical studies. Little is known on the receptor subtypes involved. We investigated the influence of the stable sst1-5 agonist, ODT8-SST and selective receptor subtype peptide agonists (3 or 10μg/mouse) injected intraperitoneally (ip) on visceral hypersensitivity in mice induced by repeated noxious colorectal distensions (four sets of three CRD, each at 55mmHg) or corticotropin-releasing factor receptor 1 agonist, cortagine given between two sets of graded CRD (15, 30, 45, and 60mmHg, three times each pressure). The mean visceromotor response (VMR) was assessed using a non-invasive manometry method and values were expressed as percentage of the VMR to the 1st set of CRD baseline or to the 60mmHg CRD, respectively. ODT8-SST (10μg) and the sst2 agonist, S-346-011 (3 and 10μg) prevented mechanically induced visceral hypersensitivity in the three sets of CRD, the sst1 agonist (10μg) blocked only the 2nd set and showed a trend at 3μg while the sst4 agonist had no effect. The selective sst2 antagonist, S-406-028 blocked the sst2 agonist but not the sst1 agonist effect. The sst1 agonist (3 and 10μg) prevented cortagine-induced hypersensitivity to CRD at each pressure while the sst2 agonist at 10μg reduced it. These data indicate that in addition to sst2, the sst1 agonist may provide a novel promising target to alleviate visceral hypersensitivity induced by mechanoreceptor sensitization and more prominently, stress-related visceral nociceptive sensitization. Copyright © 2014 Elsevier Inc. All rights reserved.

On the influence of simulated SST warming on rainfall projections in the Indo-Pacific domain: an AGCM study

NASA Astrophysics Data System (ADS)

Zhang, Huqiang; Zhao, Y.; Moise, A.; Ye, H.; Colman, R.; Roff, G.; Zhao, M.

2018-02-01

Significant uncertainty exists in regional climate change projections, particularly for rainfall and other hydro-climate variables. In this study, we conduct a series of Atmospheric General Circulation Model (AGCM) experiments with different future sea surface temperature (SST) warming simulated by a range of coupled climate models. They allow us to assess the extent to which uncertainty from current coupled climate model rainfall projections can be attributed to their simulated SST warming. Nine CMIP5 model-simulated global SST warming anomalies have been super-imposed onto the current SSTs simulated by the Australian climate model ACCESS1.3. The ACCESS1.3 SST-forced experiments closely reproduce rainfall means and interannual variations as in its own fully coupled experiments. Although different global SST warming intensities explain well the inter-model difference in global mean precipitation changes, at regional scales the SST influence vary significantly. SST warming explains about 20-25% of the patterns of precipitation changes in each of the four/five models in its rainfall projections over the oceans in the Indo-Pacific domain, but there are also a couple of models in which different SST warming explains little of their precipitation pattern changes. The influence is weaker again for rainfall changes over land. Roughly similar levels of contribution can be attributed to different atmospheric responses to SST warming in these models. The weak SST influence in our study could be due to the experimental setup applied: superimposing different SST warming anomalies onto the same SSTs simulated for current climate by ACCESS1.3 rather than directly using model-simulated past and future SSTs. Similar modelling and analysis from other modelling groups with more carefully designed experiments are needed to tease out uncertainties caused by different SST warming patterns, different SST mean biases and different model physical/dynamical responses to the same underlying SST forcing.

Seasonal trends of ACSPO VIIRS SST product characterized by the differences in orbital overlaps for various water types

NASA Astrophysics Data System (ADS)

Arnone, Robert; Vandermeulen, Ryan; Ignatov, Alexander; Cayula, Jean François

2015-05-01

The uncertainty of the Advanced Clear-Sky Processor for Oceans (ACSPO) Sea Surface Temperature (SST) products from the Visible Infrared Imaging Radiometer Suite (VIIRS) satellite is examined using consecutive orbital overlaps in coastal waters of the Gulf of Mexico. The overlapping region on the left and right side of the VIIRS swath at 23-35 degree latitude covers approximately 500 pixels, which occur within 100 minutes and can provide a total of 4 SST products (2 day and 2 night) per day. By assuming the ocean SST should be similar on each side of the swath in this short time period, diel changes are examined and the uncertainty of SST retrieval is determined by comparing with buoy-derived SST. The VIIRS ACSPO product from NOAA STAR was used to determine the difference in SST within the overlapping regions. These SST changes are evaluated between consecutive orbits to validate the accuracy of SST algorithms on each side of the swath at high sensor angles. The SST product differences across the swath can result from surface glint, sensor angular impacts and sensor characteristics such as half angle mirror side (HAM) and calibration. The absolute diurnal SST changes that can occur within 100 minutes are evaluated with the buoy and VIIRS-derived SST. Sensitivity of the SST to water types is evaluated by measuring diurnal differences for open ocean, shelf and coastal waters. The 100 minute VIIRS SST overlap shows the capability to monitor the diurnal ocean heating and cooling which are associated with water mass optical absorption. The seasonal trends of the difference in SST at the overlaps for these water masses were tracked on a monthly basis. The unique capability of using the same VIIRS sensor for self-characterization can provide a method to define the uncertainty of ocean products and characterize the diurnal changes for different water types.

F/FB-111 Avionics Test Station and Component Specialist/Technician. Automatic Test Stations Manual and Electronic Warfare Test Stations. Training Requirements Analysis (451X6). Volume 2

DTIC Science & Technology

1991-11-01

F-111D RADAR SST TASK NOTES: SST IS LOCATED ONLY AT CANNON AFB, NM. IT CONSISTS OF AN MRU , EPU, LVPS, MFG, DDPU, ARS RACK, AND TRANSMITTER. THE SST...VOTES: SST IS LOCATED ONLY AT CANNON AFB, NM. IT CONSISTS OF AN MRU , EPU, LVPS, MFG, DDPU, ARS RACK, AND TRANSMITTER. THE SST WILL BE REPLACED BY DTS...NOTES: SST IS LOCATED ONLY AT CANNON AFB, NM. IT CONSISTS OF AN MRU , EPU, LVPS, MFG, DDPU, ARS RACK, AND TRANSMITTER. THE SST WILL BE REPLACED BY DTS

Computations of Internal and External Axisymmetric Nozzle Aerodynamics at Transonic Speeds

NASA Technical Reports Server (NTRS)

Dalbello, Teryn; Georgiadis, Nicholas; Yoder, Dennis; Keith, Theo

2003-01-01

Computational Fluid Dynamics (CFD) analyses of axisymmetric circular-arc boattail nozzles have been completed in support of NASA's Next Generation Launch Technology Program to investigate the effects of high-speed nozzle geometries on the nozzle internal flow and the surrounding boattail regions. These computations span the very difficult transonic flight regime, with shock-induced separations and strong adverse pressure gradients. External afterbody and internal nozzle pressure distributions computed with the Wind code are compared with experimental data. A range of turbulence models were examined in Wind, including an Explicit Algebraic Stress model (EASM). Computations on two nozzle geometries have been completed at freestream Mach numbers ranging from 0.6 to 0.9, driven by nozzle pressure ratios (NPR) ranging from 2.9 to 5. Results obtained on converging-only geometry indicate reasonable agreement to experimental data, with the EASM and Shear Stress Transport (SST) turbulence models providing the best agreement. Calculations completed on a converging-diverging geometry involving large-scale internal flow separation did not converge to a true steady-state solution when run with variable timestepping (steady-state). Calculations obtained using constant timestepping (time-accurate) indicate less variations in flow properties compared with steady-state solutions. This failure to converge to a steady-state solution was found to be the result of difficulties in using variable time-stepping with large-scale separations present in the flow. Nevertheless, time-averaged boattail surface pressure coefficient and internal nozzle pressures show fairly good agreement with experimental data. The SST turbulence model demonstrates the best over-all agreement with experimental data.

Cogeneration steam turbines from Siemens: New solutions

NASA Astrophysics Data System (ADS)

Kasilov, V. F.; Kholodkov, S. V.

2017-03-01

The Enhanced Platform system intended for the design and manufacture of Siemens AG turbines is presented. It combines organizational and production measures allowing the production of various types of steam-turbine units with a power of up to 250 MWel from standard components. The Enhanced Platform designs feature higher efficiency, improved reliability, better flexibility, longer overhaul intervals, and lower production costs. The design features of SST-700 and SST-900 steam turbines are outlined. The SST-700 turbine is used in backpressure steam-turbine units (STU) or as a high-pressure cylinder in a two-cylinder condensing turbine with steam reheat. The design of an SST-700 single-cylinder turbine with a casing without horizontal split featuring better flexibility of the turbine unit is presented. An SST-900 turbine can be used as a combined IP and LP cylinder (IPLPC) in steam-turbine or combined-cycle power units with steam reheat. The arrangements of a turbine unit based on a combination of SST-700 and SST-900 turbines or SST-500 and SST-800 turbines are presented. Examples of this combination include, respectively, PGU-410 combinedcycle units (CCU) with a condensing turbine and PGU-420 CCUs with a cogeneration turbine. The main equipment items of a PGU-410 CCU comprise an SGT5-4000F gas-turbine unit (GTU) and STU consisting of SST-700 and SST-900RH steam turbines. The steam-turbine section of a PGU-420 cogeneration power unit has a single-shaft turbine unit with two SST-800 turbines and one SST-500 turbine giving a power output of N el. STU = 150 MW under condensing conditions.

A Fuzzy Control System for Reducing Urban Runoff by a Stormwater Storage Tank

NASA Astrophysics Data System (ADS)

Zhang, P.; Cai, Y.; Wang, J.

2017-12-01

Stormwater storage tank (SST) is a popular low impact development technology for reducing stormwater runoff in the construction of sponge city. Most researches on SST were mainly the design, pollutants removal effect, and operation assessment. While there were few researches on the automatic control of SST for reducing peak flow. In this paper, fuzzy control was introduced into the peak control of SST to improve the efficiency of reducing stormawter runoff. Firstly, the design of SST was investigated. A catchment area and return period were assumed, a SST model was manufactured, and then the storage capacity of the SST was verified. Secondly, the control parameters of the SST based on reducing stormwater runoff was analyzed, and a schematic diagram of real-time control (RTC) system based on peak control SST was established. Finally, fuzzy control system of a double input (flow and water level) and double output (inlet and outlet valve) was designed. The results showed that 1) under the different return periods (one year, three years, five years), the SST had the effect of delayed peak control and storage by increasing the detention time, 2) rainfall, pipeline flow, the influent time and the water level in the SST could be used as RTC parameters, and 3) the response curves of flow velocity and water level fluctuated very little and reached equilibrium in a short time. The combination of online monitoring and fuzzy control was feasible to control the SST automatically. This paper provides a theoretical reference for reducing stormwater runoff and improving the operation efficiency of SST.

North-East monsoon rainfall extremes over the southern peninsular India and their association with El Niño

NASA Astrophysics Data System (ADS)

Singh, Prem; Gnanaseelan, C.; Chowdary, J. S.

2017-12-01

The present study investigates the relationship between extreme north-east (NE) monsoon rainfall (NEMR) over the Indian peninsula region and El Niño forcing. This turns out to be a critical science issue especially after the 2015 Chennai flood. The puzzle being while most El Niños favour good NE monsoon, some don't. In fact some El Niño years witnessed deficit NE monsoon. Therefore two different cases (or classes) of El Niños are considered for analysis based on standardized NEMR index and Niño 3.4 index with case-1 being both Niño-3.4 and NEMR indices greater than +1 and case-2 being Niño-3.4 index greater than +1 and NEMR index less than -1. Composite analysis suggests that SST anomalies in the central and eastern Pacific are strong in both cases but large differences are noted in the spatial distribution of SST over the Indo-western Pacific region. This questions our understanding of NEMR as mirror image of El Niño conditions in the Pacific. It is noted that the favourable excess NEMR in case-1 is due to anomalous moisture transport from Bay of Bengal and equatorial Indian Ocean to southern peninsular India. Strong SST gradient between warm western Indian Ocean (and Bay of Bengal) and cool western Pacific induced strong easterly wind anomalies during NE monsoon season favour moisture transport towards the core NE monsoon region. Further anomalous moisture convergence and convection over the core NE monsoon region supported positive rainfall anomalies in case-1. While in case-2, weak SST gradients over the Indo-western Pacific and absence of local low level convergence over NE monsoon region are mainly responsible for deficit rainfall. The ocean dynamics in the Indian Ocean displayed large differences during case-1 and case-2, suggesting the key role of Rossby wave dynamics in the Indian Ocean on NE monsoon extremes. Apart from the large scale circulation differences the number of cyclonic systems land fall for case-1 and case-2 have also contributed for variations in NE monsoon rainfall extremes during El Niño years. This study indicates that despite having strong warming in the central and eastern Pacific, NE monsoon rainfall variations over the southern peninsular India is mostly determined by SST gradient over the Indo-western Pacific region and number of systems formation in the Bay of Bengal and their land fall. The paper concludes that though the favourable large scale circulation induced by Pacific is important in modulating the NE monsoon rainfall the local air sea interaction plays a key role in modulating or driving rainfall extremes associated with El Niño.

Are Sea Surface Temperature satellite measurements reliable proxies of lagoon temperature in the South Pacific?

NASA Astrophysics Data System (ADS)

Van Wynsberge, Simon; Menkes, Christophe; Le Gendre, Romain; Passfield, Teuru; Andréfouët, Serge

2017-12-01

In remote coral reef environments, lagoon and reef in situ measurements of temperature are scarce. Sea Surface Temperature (SST) measured by satellite has been frequently used as a proxy of the lagoon temperature experienced by coral reef organisms (TL) especially during coral bleaching events. However, the link between SST and TL is poorly characterized. First, we compared the correlation between various SST series and TL from 2012 to 2016 in three atolls and one island in the Central South Pacific Ocean. Simple linear correlation between SST and TL ranged between 0.44 and 0.97 depending on lagoons, localities of sensors, and type of SST data. High-resolution-satellite-measurements of SST inside the lagoons did not outperform oceanic SST series, suggesting that SST products are not adapted for small lagoons. Second, we modelled the difference between oceanic SST and TL as a function of the drivers of lagoon water renewal and mixing, namely waves, tide, wind, and season. The multivariate models reduced significantly the bias between oceanic SST and TL. In atoll lagoons, and probably in other hydrodynamically semi-open systems, a correction taking into account these factors is necessary when SST are used to characterize organisms' thermal stress thresholds.

Somatostatin, neuronal vulnerability and behavioral emotionality.

PubMed

Lin, L C; Sibille, E

2015-03-01

Somatostatin (SST) deficits are common pathological features in depression and other neurological disorders with mood disturbances, but little is known about the contribution of SST deficits to mood symptoms or causes of these deficits. Here we show that mice lacking SST (Sst(KO)) exhibit elevated behavioral emotionality, high basal plasma corticosterone and reduced gene expression of Bdnf, Cortistatin and Gad67, together recapitulating behavioral, neuroendocrine and molecular features of human depression. Studies in Sst(KO) and heterozygous (Sst(HZ)) mice show that elevated corticosterone is not sufficient to reproduce the behavioral phenotype, suggesting a putative role for Sst cell-specific molecular changes. Using laser capture microdissection, we show that cortical SST-positive interneurons display significantly greater transcriptome deregulations after chronic stress compared with pyramidal neurons. Protein translation through eukaryotic initiation factor 2 (EIF2) signaling, a pathway previously implicated in neurodegenerative diseases, was most affected and suppressed in stress-exposed SST neurons. We then show that activating EIF2 signaling through EIF2 kinase inhibition mitigated stress-induced behavioral emotionality in mice. Taken together, our data suggest that (1) low SST has a causal role in mood-related phenotypes, (2) deregulated EIF2-mediated protein translation may represent a mechanism for vulnerability of SST neurons and (3) that global EIF2 signaling has antidepressant/anxiolytic potential.

Somatostatin, neuronal vulnerability and behavioral emotionality

PubMed Central

Lin, LC; Sibille, E

2014-01-01

Somatostatin (SST) deficits are common pathological features in depression and other neurological disorders with mood disturbances, but little is known about the contribution of SST deficits to mood symptoms or causes of these deficits. Here we show that mice lacking Sst (SstKO) exhibit elevated behavioral emotionality, high basal plasma corticosterone and reduced gene expression of Bdnf, Cortistatin, and Gad67, together recapitulating behavioral, neuroendocrine and molecular features of human depression. Studies in SstKO and heterozygous (SstHZ) mice show that elevated corticosterone is not sufficient to reproduce the behavioral phenotype, suggesting a putative role for Sst cell-specific molecular changes. Using laser-capture microdissection, we show that cortical SST-positive interneurons display significantly greater transcriptome deregulations after chronic stress compared to pyramidal neurons. Protein translation through eukaryotic initiation factor 2 (EIF2) signaling, a pathway previously implicated in neurodegenerative diseases, was most affected and suppressed in stress-exposed SST neurons. We then show that activating EIF2 signaling through EIF2 kinase inhibition mitigated stress-induced behavioral emotionality in mice. Together, our data suggest that (1) low SST plays a causal role in mood-related phenotypes, (2) deregulated EIF2-mediated protein translation may represent a mechanism for vulnerability of SST neurons, and (3) that global EIF2 signaling has antidepressant/anxiolytic potential. PMID:25600109

The effect of atmospheric variability at intra-seasonal time scale on the SST of the Southwestern Atlantic Continental Shelf

NASA Astrophysics Data System (ADS)

Simionato, Claudia; Clara, Moira Luz; Jaureguizar, Andrés

2017-04-01

The Southwestern Atlantic Continental Shelf is characterized by large SST variability which origin remains unknown. In this work, we use blended SST data provided by NOAA CoastWatch Program, which combine the information coming from infrared and microwave sensors to provide daily images of an intermediate spatial resolution (11 km) with a noise floor of less than 0.2 °C. The data base starts at the middle of 2002, when an increase in signal variance is observed due to the fact that the Advanced Microwave Scanning Radiometer became available and as a consequence to its near all-weather coverage. Several years of observations are thus available, and even though the temporal and spatial resolution of these data is intermediate, they are reasonable for observing and characterizing the most significant patterns of SST variability in the (atmospheric) synoptic to intra-seasonal time scales, so as to help on understanding the physical processes which occur in the area and their forcing mechanisms. As we hypothesize that most of the variability in those time scales is wind forced, the study is complemented with the use of atmospheric observations -coming from remote sensing and reanalysis-. To perform the analysis, the long-term trend, inter-annual and seasonal variability are subtracted to the SST data to obtain the signal on intra-seasonal time scales. Then, Principal Components (EOF) analysis is applied to the data and composites of SST and several meteorological variables (wind, sea level pressure, air temperature, OLR, etc.) are computed for the days when the leading modes are active. It is found that the first three modes account for more than 70% of the variance. Modes 1 and 2 seem to be related to atmospheric waves generated in the tropical Pacific. Those waves, through atmospheric teleconnections, affect the SST on the southwestern South Atlantic Continental Shelf very rapidly. The oceanic anomalies exceed 0.7°C and are quite persistent. Mode 2 seems to be forced by an atmospheric 3-4 mode and might be related to SAM. Besides showing the impact of intra-seasonal atmospheric variability on the ocean at mid latitudes, the knowledge of the connections between the ocean and the atmosphere could aid on improving the ocean predictability on those time scales.

Variability of CO2 fugacity at the western edge of the tropical Atlantic Ocean from the 8°N to 38°W PIRATA buoy

NASA Astrophysics Data System (ADS)

Bruto, Leonardo; Araujo, Moacyr; Noriega, Carlos; Veleda, Dóris; Lefèvre, Nathalie

2017-06-01

Hourly data of CO2 fugacity (fCO2) at 8°N-38°W were analyzed from 2008 to 2011. Analyses of wind, rainfall, temperature and salinity data from the buoy indicated two distinct seasonal periods. The first period (January to July) had a mean fCO2 of 378.9 μatm (n = 7512). During this period, in which the study area was characterized by small salinity variations, the fCO2 is mainly controlled by sea surface temperature (SST) variations (fCO2 = 24.4*SST-281.1, r2 = 0.8). During the second period (August-December), the mean fCO2 was 421.9 μatm (n = 11571). During these months, the region is subjected to the simultaneous action of (a) rainfall induced by the presence of the Intertropical Convergence Zone (ITCZ); (b) arrival of fresh water from the Amazon River plume that is transported to the east by the North Equatorial Countercurrent (NECC) after the retroflection of the North Brazil Current (NBC); and (c) vertical input of CO2-rich water due to Ekman pumping. The data indicated the existence of high-frequency fCO2 variability (periods less than 24 h). This high variability is related to two different mechanisms. In the first mechanism, fCO2 increases are associated to rapid increases in SST and are attributed to the diurnal cycle of solar radiation. In addition, low wind speed contributes to SST rising by inhibiting vertical mixing. In the second mechanism, fCO2 decreases are associated to SSS decreases caused by heavy rainfall.

Alleviating tropical Atlantic sector biases in the Kiel climate model by enhancing horizontal and vertical atmosphere model resolution: climatology and interannual variability

NASA Astrophysics Data System (ADS)

Harlaß, Jan; Latif, Mojib; Park, Wonsun

2018-04-01

We investigate the quality of simulating tropical Atlantic (TA) sector climatology and interannual variability in integrations of the Kiel climate model (KCM) with varying atmosphere model resolution. The ocean model resolution is kept fixed. A reasonable simulation of TA sector annual-mean climate, seasonal cycle and interannual variability can only be achieved at sufficiently high horizontal and vertical atmospheric resolution. Two major reasons for the improvements are identified. First, the western equatorial Atlantic westerly surface wind bias in spring can be largely eliminated, which is explained by a better representation of meridional and especially vertical zonal momentum transport. The enhanced atmospheric circulation along the equator in turn greatly improves the thermal structure of the upper equatorial Atlantic with much reduced warm sea surface temperature (SST) biases. Second, the coastline in the southeastern TA and steep orography are better resolved at high resolution, which improves wind structure and in turn reduces warm SST biases in the Benguela upwelling region. The strongly diminished wind and SST biases at high atmosphere model resolution allow for a more realistic latitudinal position of the intertropical convergence zone. Resulting stronger cross-equatorial winds, in conjunction with a shallower thermocline, enable a rapid cold tongue development in the eastern TA in boreal spring. This enables simulation of realistic interannual SST variability and its seasonal phase locking in the KCM, which primarily is the result of a stronger thermocline feedback. Our findings suggest that enhanced atmospheric resolution, both vertical and horizontal, could be a key to achieving more realistic simulation of TA climatology and interannual variability in climate models.

Interannual Variation in Offshore Advection of Amazon-Orinoco Plume Waters: Observations, Forcing Mechanisms, and Impacts

NASA Astrophysics Data System (ADS)

Fournier, S.; Vandemark, D. C.; Gaultier, L.; Lee, T.; Jonsson, B. F.; Gierach, M. M.

2017-12-01

Sea surface salinity (SSS) and sea surface temperature (SST) variations in the tropical Atlantic east of the Lesser Antilles, a region impacted by freshwater advection from the Amazon and Orinoco Rivers have potential implications to late-summer tropical cyclones (TCs). This study examines these variations during late summer and their forcing mechanisms using observations. During the period 2010-2014, the largest difference in plume-affected area, defined as the extent covered by SSS lower than 35.5 pss, is found between 2011 and 2014. Plume waters covered 92% (60%) of the study region in 2011 (2014) with the averaged SSS in the study region being 2-pss lower in 2011. Lagrangian particle tracking based on satellite-derived ocean currents is used to diagnose the impacts of the river plumes on SSS and SST during 2010-2014. Northward freshwater flux in the summer of 2014 is significantly weaker than those in 2010-2013. This is not due to interannual discharge variability, but significant changes in eddy-driven transport and cross-shore winds. In particular, the stronger cross-shore wind in May 2014 restricted offshore freshwater flow, leading to a smaller extent of the plume-affected area. Persistent SST gradients are often found near the plume edge, which may have implication to ocean-atmosphere coupling associated with TC-related convection. SST in the study region is 1°C higher in 2010 than in other years, and is related to basin-scale ocean-atmosphere processes. Interannual variation in Amazon advective pathways and the associated SSS changes are also influenced by changes in the ITCZ position between 2011 and 2014.

Variability in Bias of Gridded Sea Surface Temperature Data Products: Implications for Seasonally Resolved Marine Proxy Reconstructions

NASA Astrophysics Data System (ADS)

Ouellette, G., Jr.; DeLong, K. L.

2016-12-01

Seasonally resolved reconstructions of sea surface temperature (SST) are commonly produced using isotopic ratios and trace elemental ratios within the skeletal material of marine organisms such as corals, coralline algae, and mollusks. Using these geochemical proxies to produce paleoclimate reconstructions requires using regression methods to calibrate the proxy to observed SST, ideally with in situ SST records that span many years. Unfortunately, the few locations with in situ SST records rarely coincide with the time span of the marine proxy archive. Therefore, SST data products are often used for calibration and they are based on MOHSST or ICOADS SST observations as their main SST source but use different algorithms to produce globally gridded data products. These products include the Hadley Center's HADSST (5º) and interpolated HADISST (1º), NOAA's extended reconstructed SST (ERSST; 2º), optimum interpolation SST (OISST; 1º), and the Kaplan SST (5º). This study assessed the potential bias in these data products at marine archive sites throughout the tropical Atlantic using in situ SST where it was available, and a high-resolution (4 km) satellite-based SST data product from NOAA Pathfinder that has been shown to closely reflect in situ SST for our locations. Bias was assessed at each site, and then within each data product across the region for spatial homogeneity. Our results reveal seasonal biases in all data products, but not for all locations and not of a uniform magnitude or season among products. We found the largest differences in mean SST on the order of 1-3°C for single sites in the Gulf of Mexico, and differences for regional mean SST bias were 0.5-1°C when sites in the Gulf of Mexico were compared to sites in the Caribbean Sea within the same data product. No one SST data product outperformed the others and no systematic bias was found. This analysis illustrates regional strengths and weaknesses of these data products, and serves as a cautionary note against the wholesale use of a particular gridded data product for marine proxy calibration, whether for a single site or larger regional reconstruction, without considering the inherent heterogeneous bias present in each data product that we show varies among locations. Furthermore, this study has implications for comparing climate models and these SST data products.

Effects of the Changiang river discharge on the change in ocean and atmosphere over the East Asian region

NASA Astrophysics Data System (ADS)

Kim, M. H.; Lim, Y. J.; Kang, H. S.; Kim, B. J.; Cho, C.

2017-12-01

This study investigates the effects of freshwater from the Changiang river basin over the East Asian region for summer season. To do this, we simulated global seasonal forecasting system (GloSea5) of KMA (Korea Meteorology Administration). GloSea5 consists of atmosphere, ocean, sea ice and land model. Also, it has river routing model (TRIP), which links between land and ocean using freshwater. It is very important component in long-term forecast because of be able to change the air-sea interaction. To improve more the freshwater performance over the East Asian region, we realistically modified the river mouth, direction and storage around Changiang river basin of TRIP in GloSea5. Here, the comparison study among the no freshwater forcing experiment to ocean model (TRIP-OFF), the operated original file based freshwater coupled experiment (TRIP-ON) and the improved one (TRIP-MODI) has been carried out and the results are evaluated against the reanalysis data. As a result, the amount of fresh water to the Yellow Sea increase in TRIP-ON experiment and it attributes to the improvement of bias and RMSE of local SST over the East Asia. The implementation of the realistic river related ancillary files (TRIP-MODI) improves the abnormal salinity distribution around the Changjiang river gate and its related SST reduces cold bias about 0.37˚C for July over the East Sea. Warm SST over this region is caused by barrier layer (BL). Freshwater flux and salinity changes can create a pronounced salinity-induced mixed layer (ML) above the top of the thermocline. The layer between the base of the ML and the top of the thermocline is called a barrier layer (BL), because it isolates the warm surface water from cold deep water. In addition, the improved fresh water forcing can lead to the change in the local volume transport from the Kuroshio to the Strait of Korea and Changed the transport and SST over the Straits of Korea have correlation 0.57 at 95% confidence level. For the atmospheric variables in East Asian region, the error statistics of temperature in TRIP-MODI is the best, reducing about 0.32˚C for July but there is no difference of the precipitation distribution among the experiments.

Large-scale effects on the regulation of tropical sea surface temperature

NASA Technical Reports Server (NTRS)

Hartmann, Dennis L.; Michelsen, Marc L.

1993-01-01

The dominant terms in the surface energy budget of the tropical oceans are absorption of solar radiation and evaporative cooling. If it is assumed that relative humidity in the boundary layer remains constant, evaporative cooling will increase rapidly with sea surface temperature (SST) because of the strong temperature dependence of saturation water vapor pressure. The resulting stabilization of SST provided by evaporative cooling is sufficient to overcome positive feedback contributed by the decrease of surface net longwave cooling with increasing SST. Evaporative cooling is sensitive to small changes in boundary-layer relative humidity. Large and negative shortwave cloud forcing in the regions of highest SST are supported by the moisture convergence associated with largescale circulations. In the descending portions of these circulations the shortwave cloud forcing is suppressed. When the effect of these circulations is taken into account by spatial averaging, the area-averaged cloud forcing shows no sensitivity to area-averaged SST changes associated with the 1987 warming event in the tropical Pacific. While the shortwave cloud forcing is large and important in the convective regions, the importance of its role in regulating the average temperature of the tropics and in modulating temperature gradients within the tropics is less clear. A heuristic model of SST is used to illustrate the possible role of large-scale atmospheric circulations on SST in the tropics and the coupling between SST gradients and mean tropical SST. The intensity of large-scale circulations responds sensitivity to SST gradients and affects the mean tropical SST by supplying dry air to the planetary boundary layer. Large SST gradients generate vigorous circulations that increase evaporation and reduce the mean SST.

Changes in neuronal response to ischemia in retinas with genetic alterations of somatostatin receptor expression.

PubMed

Catalani, Elisabetta; Cervia, Davide; Martini, Davide; Bagnoli, Paola; Simonetti, Elisa; Timperio, Anna Maria; Casini, Giovanni

2007-03-01

Ischemia is a primary cause of neuronal death in retinal diseases. The repertoire of expressed transmitter receptors would determine the neurons' responses to ischemic damage, and peptidergic receptors may be involved. With a new in vitro model of the ischemic mouse retina, we investigated whether an altered expression of somatostatin receptors could modulate retinal responses to ischemia. We used retinas of somatostatin receptor 1 (sst(1)) knock out (KO) mice, where sst(2) are over-expressed and over-functional, and of sst(2) KO mice. TUNEL analysis of ischemic retinas showed a marked reduction of cell death in sst(1) KO retinas, while there were no differences between wild-type (WT) and sst(2) KO retinas. In addition, caspase-3 mRNA expression was also reduced in sst(1) KO as compared to WT retinas. An immunohistochemical analysis demonstrated that different cell populations responded differently to the ischemic insult, and that the persistence of some immunohistochemical markers was greater in sst(1) KO than in WT or in sst(2) KO retinas. In particular, rod bipolar cell survival was markedly improved in sst(1) KO retinas, while it was dramatically decreased in sst(2) KO retinas. Furthermore, consistent with a role of glutamate excitotoxicity in ischemia-induced neuronal death, retinal glutamate release was observed to increase under ischemic conditions, but this increase was significantly reduced in sst(1) KO retinas. These observations demonstrate that an increased presence of functional sst(2) protects against retinal ischemia, thus implementing the background for the use of sst(2) analogs in therapies of retinal diseases such as glaucoma or diabetic retinopathy.

Observations of Local Positive Low Cloud Feedback Patterns and Their Role in Internal Variability and Climate Sensitivity

NASA Astrophysics Data System (ADS)

Yuan, Tianle; Oreopoulos, Lazaros; Platnick, Steven E.; Meyer, Kerry

2018-05-01

Modeling studies have shown that cloud feedbacks are sensitive to the spatial pattern of sea surface temperature (SST) anomalies, while cloud feedbacks themselves strongly influence the magnitude of SST anomalies. Observational counterparts to such patterned interactions are still needed. Here we show that distinct large-scale patterns of SST and low-cloud cover (LCC) emerge naturally from objective analyses of observations and demonstrate their close coupling in a positive local SST-LCC feedback loop that may be important for both internal variability and climate change. The two patterns that explain the maximum amount of covariance between SST and LCC correspond to the Interdecadal Pacific Oscillation and the Atlantic Multidecadal Oscillation, leading modes of multidecadal internal variability. Spatial patterns and time series of SST and LCC anomalies associated with both modes point to a strong positive local SST-LCC feedback. In many current climate models, our analyses suggest that SST-LCC feedback strength is too weak compared to observations. Modeled local SST-LCC feedback strength affects simulated internal variability so that stronger feedback produces more intense and more realistic patterns of internal variability. To the extent that the physics of the local positive SST-LCC feedback inferred from observed climate variability applies to future greenhouse warming, we anticipate significant amount of delayed warming because of SST-LCC feedback when anthropogenic SST warming eventually overwhelm the effects of internal variability that may mute anthropogenic warming over parts of the ocean. We postulate that many climate models may be underestimating both future warming and the magnitude of modeled internal variability because of their weak SST-LCC feedback.

Highly Increased 125I-JR11 Antagonist Binding In Vitro Reveals Novel Indications for sst2 Targeting in Human Cancers.

PubMed

Reubi, Jean Claude; Waser, Beatrice; Mäcke, Helmut; Rivier, Jean

2017-02-01

There is recent in vitro and in vivo evidence that somatostatin receptor subtype 2 (sst 2 ) antagonists are better tools to target neuroendocrine tumors (NETs) than sst 2 agonists. Indeed, antagonists bind to a greater number of sst 2 sites than agonists. Whether sst 2 antagonists could be used successfully to target non-NETs, expressing low sst 2 density, is unknown. Here, we compare quantitatively 125 I-JR11 sst 2 antagonist binding in vitro with that of the sst 2 agonist 125 I-Tyr 3 -octreotide in large varieties of non-NET and NET. In vitro receptor autoradiography was performed with 125 I-JR11 and 125 I-Tyr 3 -octreotide in cancers from prostate, breast, colon, kidney, thyroid, and lymphoid tissues as well as NETs as reference. In general, 125 I-JR11 binds to many more sst 2 sites than 125 I-Tyr 3 -octreotide. In 13 breast cancers, 8 had a low binding (mean density, 844 ± 168 dpm/mg of tissue) with the agonist whereas 12 had a high binding (mean density, 4,447 ± 1,128 dpm/mg of tissue) with the antagonist. All 12 renal cell cancers showed a low binding of sst 2 with the agonist (mean density, 348 ± 49 dpm/mg of tissue) whereas all cases had a high sst 2 binding with the antagonist (mean density, 3,777 ± 582 dpm/mg of tissue). One of 5 medullary thyroid cancers was positive with the agonist, whereas 5 of 5 were positive with the antagonist. In 15 non-Hodgkin lymphomas, many more sst 2 sites were labeled with the antagonist than with the agonist. In 14 prostate cancers, none had sst 2 binding with the agonist and only 4 had a weak binding with the antagonist. None of 17 colon cancers showed sst 2 sites with the agonist, and only 3 cases were weakly positive with the antagonist. In the various tumor types, adjacent sst 2 -expressing tissues such as vessels, lymphocytes, nerves, mucosa, or stroma were more strongly labeled with the antagonist than with the agonist. The reference NET cases, incubated with a smaller amount of tracer, were also found to have many more sst 2 sites measured with the antagonist. All renal cell cancers and most breast cancers, non-Hodgkin lymphomas, and medullary thyroid cancers represent novel indications for the in vivo radiopeptide targeting of sst 2 by sst 2 antagonists, comparable to NET radiotargeting with sst 2 agonists. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

Molecular evidence and clinical importance of β-arrestins expression in patients with acromegaly.

PubMed

Coelho, Maria Caroline Alves; Vasquez, Marina Lipkin; Wildemberg, Luiz Eduardo; Vázquez-Borrego, Mari C; Bitana, Luciana; Camacho, Aline Helen da Silva; Silva, Débora; Ogino, Liana Lumi; Ventura, Nina; Chimelli, Leila; Luque, Raul M; Kasuki, Leandro; Gadelha, Mônica R

2018-04-01

β-arrestins seem to have a role in endocytosis and desensitization of somatostatin receptor subtype 2 (sst2) and could be associated with the responsiveness to somatostatin receptor ligands (SRL) in patients with acromegaly. To investigate the in vivo correlation between β-arrestins 1 and 2 with sst2, sst5 and dopamine receptor subtype 2 (D2) expressions, and the association of β-arrestins with response to first-generation SRL and invasiveness in somatotropinomas. β-arrestins 1 and 2, sst2, sst5 and D2 mRNA expressions were evaluated by quantitative real-time RT-PCR on tumoral tissue of 96 patients. Moreover, sst2 and sst5 protein expressions were also evaluated in 40 somatotropinomas by immunohistochemistry. Response to SRL, defined as GH <1 μg/l and normal IGF-I levels, was assessed in 40 patients. The Knosp-Steiner criteria were used to define invasiveness. Median β-arrestin 1, β-arrestin 2, sst2, sst5 and D2 mRNA copy numbers were 478; 9375; 731; 156; and 3989, respectively. There was a positive correlation between β-arrestins 1 and 2 (R = 0.444, P < 0.001). However, no correlation between β-arrestins and sst2, sst5 (mRNA and protein levels) or D2 was found. No association was found between β-arrestins expression and SRL responsiveness or tumour invasiveness. Although previous data suggest a putative correlation between β-arrestins and sst2, our data clearly indicated that no association existed between β-arrestins and sst2, sst5 or D2 expression, nor with response to SRL or tumour invasiveness. Therefore, further studies are required to clarify whether β-arrestins have a role in the response to treatment with SRL in acromegaly. © 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

How does the Redi parameter for mesoscale mixing impact global climate in an Earth System Model?

NASA Astrophysics Data System (ADS)

Pradal, Marie-Aude; Gnanadesikan, Anand

2014-09-01

A coupled climate model is used to examine the impact of an increase in the mixing due to mesoscale eddies on the global climate system. A sixfold increase in the Redi mixing coefficient ARedi, which is within the admissible range of variation, has the overall effect of warming the global-mean surface air and sea surface temperatures by more than 1°C. Locally, sea surface temperatures increase by up to 7°C in the North Pacific and by up to 4°C in the Southern Ocean, with corresponding impacts on the ice concentration and ice extent in polar regions. However, it is not clear that the changes in heat transport from tropics to poles associated with changing this coefficient are primarily responsible for these changes. We found that the changes in the transport of heat are often much smaller than changes in long-wave trapping and short-wave absorption. Additionally, changes in the advective and diffusive transport of heat toward the poles often oppose each other. However, we note that the poleward transport of salt increases near the surface as ARedi increases. We suggest a causal chain in which enhanced eddy stirring leads to increased high-latitude surface salinity reducing salt stratification and water column stability and enhancing convection, triggering two feedback loops. In one, deeper convection prevents sea ice formation, which decreases albedo, which increases SW absorption, further increasing SST and decreasing sea ice formation. In the other, increased SST and reduced sea ice allow for more water vapor in the atmosphere, trapping long-wave radiation. Destratifying the polar regions is thus a potential way in which changes in ocean circulation might warm the planet.

Transient enhancement of GLUT-4 levels in rat epitrochlearis muscle after exercise training

PubMed Central

Reynolds, Thomas H.; Brozinick, Joseph T.; Larkin, Lisa M.; Cushman, Samuel W.

2009-01-01

The purpose of the present study was to examine the effect of detraining on the glucose transport system after short-term swim training (5 days), long-term swim training (5 wk), and treadmill run training (5 wk). Skeletal muscles were isolated from female Wistar rats at 24 or 48 h posttraining. SST produces a 48% increase in GLUT-4 mRNA, a 30% increase in GLUT-4 protein, and a 60% increase in insulin-stimulated glucose transport activity at 24 h posttraining but not at 48 h posttraining. Similar to SST, long-term swim training produces a 60% increase in GLUT-4 mRNA and a 30% increase in GLUT-4 protein content at 24 h posttraining but not at 48 h posttraining. Finally, treadmill run training produces a transient 35% increase in GLUT-4 protein content that is completely reversed at 48 h after the last bout of exercise. These results demonstrate that the increase in GLUT-4 mRNA and GLUT-4 protein occurs during the first week of exercise training and is rapidly lost after training cessation. We believe that the transient enhancement in GLUT-4 protein after exercise training is due to a short GLUT-4 half-life, a process that is primarily regulated by pretranslational mechanisms. PMID:10846041

Bifurcation analysis of delay-induced resonances of the El-Niño Southern Oscillation

PubMed Central

Krauskopf, Bernd; Sieber, Jan

2014-01-01

Models of global climate phenomena of low to intermediate complexity are very useful for providing an understanding at a conceptual level. An important aspect of such models is the presence of a number of feedback loops that feature considerable delay times, usually due to the time it takes to transport energy (for example, in the form of hot/cold air or water) around the globe. In this paper, we demonstrate how one can perform a bifurcation analysis of the behaviour of a periodically forced system with delay in dependence on key parameters. As an example, we consider the El-Niño Southern Oscillation (ENSO), which is a sea-surface temperature (SST) oscillation on a multi-year scale in the basin of the Pacific Ocean. One can think of ENSO as being generated by an interplay between two feedback effects, one positive and one negative, which act only after some delay that is determined by the speed of transport of SST anomalies across the Pacific. We perform here a case study of a simple delayed-feedback oscillator model for ENSO, which is parametrically forced by annual variation. More specifically, we use numerical bifurcation analysis tools to explore directly regions of delay-induced resonances and other stability boundaries in this delay-differential equation model for ENSO. PMID:25197254

Transient enhancement of GLUT-4 levels in rat epitrochlearis muscle after exercise training.

PubMed

Reynolds, T H; Brozinick, J T; Larkin, L M; Cushman, S W

2000-06-01

The purpose of the present study was to examine the effect of detraining on the glucose transport system after short-term swim training (5 days), long-term swim training (5 wk), and treadmill run training (5 wk). Skeletal muscles were isolated from female Wistar rats at 24 or 48 h posttraining. SST produces a 48% increase in GLUT-4 mRNA, a 30% increase in GLUT-4 protein, and a 60% increase in insulin-stimulated glucose transport activity at 24 h posttraining but not at 48 h posttraining. Similar to SST, long-term swim training produces a 60% increase in GLUT-4 mRNA and a 30% increase in GLUT-4 protein content at 24 h posttraining but not at 48 h posttraining. Finally, treadmill run training produces a transient 35% increase in GLUT-4 protein content that is completely reversed at 48 h after the last bout of exercise. These results demonstrate that the increase in GLUT-4 mRNA and GLUT-4 protein occurs during the first week of exercise training and is rapidly lost after training cessation. We believe that the transient enhancement in GLUT-4 protein after exercise training is due to a short GLUT-4 half-life, a process that is primarily regulated by pretranslational mechanisms.

Novel sst2-selective somatostatin agonists. Three-dimensional consensus structure by NMR

PubMed Central

Grace, Christy Rani R.; Erchegyi, Judit; Koerber, Steven C.; Reubi, Jean Claude; Rivier, Jean; Riek, Roland

2008-01-01

The three-dimensional NMR structures of six octapeptide agonist analogues of somatostatin (SRIF) in the free form are described. These analogues, with the basic sequence H-DPhe/Phe2-c[Cys3-Xxx7-DTrp8-Lys9-Thr10-Cys14]-Thr-NH2 (the numbering refers to the position in native SRIF), with Xxx7 being Ala/Aph, exhibit potent and highly selective binding to human SRIF type 2 (sst2) receptors. The backbone of these sst2-selective analogues have the usual type-II’ β-turn reported in the literature for sst2/3/5-subtype-selective analogues. Correlating biological results and NMR studies led to the identification of the side chains of DPhe2, DTrp8 and Lys9 as the necessary components of the sst2 pharmacophore. This is the first study to show that the aromatic ring at position 7 (Phe7) is not critical for sst2 binding and that it plays an important role in sst3 and sst5 binding. This pharmacophore is therefore different from that proposed by others for sst2/3/5 analogues. PMID:16854054

A reduction in the asymmetry of ENSO amplitude due to global warming: The role of atmospheric feedback

NASA Astrophysics Data System (ADS)

Ham, Yoo-Geun

2017-08-01

This study analyzes a reduction in the asymmetry of El Niño Southern-Oscillation (ENSO) amplitude due to global warming in Coupled Model Intercomparison Project Phase 5 models. The multimodel-averaged Niño3 skewness during December-February season decreased approximately 40% in the RCP4.5 scenario compared to that in the historical simulation. The change in the nonlinear relationship between sea surface temperature (SST) and precipitation is a key factor for understanding the reduction in ENSO asymmetry due to global warming. In the historical simulations, the background SST leading to the greatest precipitation sensitivity (SST for Maximum Precipitation Sensitivity, SST_MPS) occurs when the positive SST anomaly is located over the equatorial central Pacific. Therefore, an increase in climatological SST due to global warming weakens the atmospheric response during El Niño over the central Pacific. However, the climatological SST over this region in the historical simulation is still lower than the SST_MPS for the negative SST anomaly; therefore, a background SST increase due to global warming can further increase precipitation sensitivity. The atmospheric feedbacks during La Niña are enhanced and increase the La Niña amplitude due to global warming.

Cloning, Developmental, and Tissue-Specific Expression of Sucrose:Sucrose 1-Fructosyl Transferase from Taraxacum officinale. Fructan Localization in Roots1

PubMed Central

Van den Ende, Wim; Michiels, An; Van Wonterghem, Dominik; Vergauwen, Rudy; Van Laere, André

2000-01-01

Sucrose:sucrose 1-fructosyl transferase (1-SST) is the key enzyme initiating fructan synthesis in Asteraceae. Using reverse transcriptase-PCR, we isolated the cDNA for 1-SST from Taraxacum officinale. The cDNA-derived amino acid sequence showed very high homology to other Asteracean 1-SSTs (Cichorium intybus 86%, Cynara scolymus 82%, Helianthus tuberosus 80%), but homology to 1-SST from Allium cepa (46%) and Aspergillus foetidus (18%) was much lower. Fructan concentrations, 1-SST activities, 1-SST protein, and mRNA concentrations were compared in different organs during vegetative and generative development of T. officinale plants. Expression of 1-SST was abundant in young roots but very low in leaves. 1-SST was also expressed at the flowering stages in roots, stalks, and receptacles. A good correlation was found between northern and western blots showing transcriptional regulation of 1-SST. At the pre-flowering stage, 1-SST mRNA concentrations and 1-SST activities were higher in the root phloem than in the xylem, resulting in the higher fructan concentrations in the phloem. Fructan localization studies indicated that fructan is preferentially stored in phloem parenchyma cells in the vicinity of the secondary sieve tube elements. However, inulin-like crystals occasionally appeared in xylem vessels. PMID:10806226

Assessing recent warming using instrumentally homogeneous sea surface temperature records.

PubMed

Hausfather, Zeke; Cowtan, Kevin; Clarke, David C; Jacobs, Peter; Richardson, Mark; Rohde, Robert

2017-01-01

Sea surface temperature (SST) records are subject to potential biases due to changing instrumentation and measurement practices. Significant differences exist between commonly used composite SST reconstructions from the National Oceanic and Atmospheric Administration's Extended Reconstruction Sea Surface Temperature (ERSST), the Hadley Centre SST data set (HadSST3), and the Japanese Meteorological Agency's Centennial Observation-Based Estimates of SSTs (COBE-SST) from 2003 to the present. The update from ERSST version 3b to version 4 resulted in an increase in the operational SST trend estimate during the last 19 years from 0.07° to 0.12°C per decade, indicating a higher rate of warming in recent years. We show that ERSST version 4 trends generally agree with largely independent, near-global, and instrumentally homogeneous SST measurements from floating buoys, Argo floats, and radiometer-based satellite measurements that have been developed and deployed during the past two decades. We find a large cooling bias in ERSST version 3b and smaller but significant cooling biases in HadSST3 and COBE-SST from 2003 to the present, with respect to most series examined. These results suggest that reported rates of SST warming in recent years have been underestimated in these three data sets.

BIM-23A760 influences key functional endpoints in pituitary adenomas and normal pituitaries: molecular mechanisms underlying the differential response in adenomas

PubMed Central

Ibáñez-Costa, Alejandro; López-Sánchez, Laura M.; Gahete, Manuel D.; Rivero-Cortés, Esther; Vázquez-Borrego, Mari C.; Gálvez, María A.; de la Riva, Andrés; Venegas-Moreno, Eva; Jiménez-Reina, Luis; Moreno-Carazo, Alberto; Tinahones, Francisco J.; Maraver-Selfa, Silvia; Japón, Miguel A.; García-Arnés, Juan A.; Soto-Moreno, Alfonso; Webb, Susan M.; Kineman, Rhonda D.; Culler, Michael D.; Castaño, Justo P.; Luque, Raúl M.

2017-01-01

Chimeric somatostatin/dopamine compounds such as BIM-23A760, an sst2/sst5/D2 receptors-agonist, have emerged as promising new approaches to treat pituitary adenomas. However, information on direct in vitro effects of BIM-23A760 in normal and tumoral pituitaries remains incomplete. The objective of this study was to analyze BIM-23A760 effects on functional parameters (Ca2+ signaling, hormone expression/secretion, cell viability and apoptosis) in pituitary adenomas (n = 74), and to compare with the responses of normal primate and human pituitaries (n = 3–5). Primate and human normal pituitaries exhibited similar sst2/sst5/D2 expression patterns, wherein BIM-23A760 inhibited the expression/secretion of several pituitary hormones (specially GH/PRL), which was accompanied by increased sst2/sst5/D2 expression in primates and decreased Ca2+ concentration in human cells. In tumoral pituitaries, BIM-23A760 also inhibited Ca2+ concentration, hormone secretion/expression and proliferation. However, BIM-23A760 elicited stimulatory effects in a subset of GHomas, ACTHomas and NFPAs in terms of Ca2+ signaling and/or hormone secretion, which was associated with the relative somatostatin/dopamine-receptors levels, especially sst5 and sst5TMD4. The chimeric sst2/sst5/D2 compound BIM-23A760 affects multiple, clinically relevant parameters on pituitary adenomas and may represent a valuable therapeutic tool. The relative ssts/D2 expression profile, particularly sst5 and/or sst5TMD4 levels, might represent useful molecular markers to predict the ultimate response of pituitary adenomas to BIM-23A760. PMID:28181484

BIM-23A760 influences key functional endpoints in pituitary adenomas and normal pituitaries: molecular mechanisms underlying the differential response in adenomas.

PubMed

Ibáñez-Costa, Alejandro; López-Sánchez, Laura M; Gahete, Manuel D; Rivero-Cortés, Esther; Vázquez-Borrego, Mari C; Gálvez, María A; de la Riva, Andrés; Venegas-Moreno, Eva; Jiménez-Reina, Luis; Moreno-Carazo, Alberto; Tinahones, Francisco J; Maraver-Selfa, Silvia; Japón, Miguel A; García-Arnés, Juan A; Soto-Moreno, Alfonso; Webb, Susan M; Kineman, Rhonda D; Culler, Michael D; Castaño, Justo P; Luque, Raúl M

2017-02-09

Chimeric somatostatin/dopamine compounds such as BIM-23A760, an sst2/sst5/D 2 receptors-agonist, have emerged as promising new approaches to treat pituitary adenomas. However, information on direct in vitro effects of BIM-23A760 in normal and tumoral pituitaries remains incomplete. The objective of this study was to analyze BIM-23A760 effects on functional parameters (Ca 2+ signaling, hormone expression/secretion, cell viability and apoptosis) in pituitary adenomas (n = 74), and to compare with the responses of normal primate and human pituitaries (n = 3-5). Primate and human normal pituitaries exhibited similar sst2/sst5/D2 expression patterns, wherein BIM-23A760 inhibited the expression/secretion of several pituitary hormones (specially GH/PRL), which was accompanied by increased sst2/sst5/D2 expression in primates and decreased Ca 2+ concentration in human cells. In tumoral pituitaries, BIM-23A760 also inhibited Ca 2+ concentration, hormone secretion/expression and proliferation. However, BIM-23A760 elicited stimulatory effects in a subset of GHomas, ACTHomas and NFPAs in terms of Ca 2+ signaling and/or hormone secretion, which was associated with the relative somatostatin/dopamine-receptors levels, especially sst5 and sst5TMD4. The chimeric sst2/sst5/D 2 compound BIM-23A760 affects multiple, clinically relevant parameters on pituitary adenomas and may represent a valuable therapeutic tool. The relative ssts/D 2 expression profile, particularly sst5 and/or sst5TMD4 levels, might represent useful molecular markers to predict the ultimate response of pituitary adenomas to BIM-23A760.

Correcting infrared satellite estimates of sea surface temperature for atmospheric water vapor attenuation

NASA Technical Reports Server (NTRS)

Emery, William J.; Yu, Yunyue; Wick, Gary A.; Schluessel, Peter; Reynolds, Richard W.

1994-01-01

A new satellite sea surface temperature (SST) algorithm is developed that uses nearly coincident measurements from the microwave special sensor microwave imager (SSM/I) to correct for atmospheric moisture attenuation of the infrared signal from the advanced very high resolution radiometer (AVHRR). This new SST algorithm is applied to AVHRR imagery from the South Pacific and Norwegian seas, which are then compared with simultaneous in situ (ship based) measurements of both skin and bulk SST. In addition, an SST algorithm using a quadratic product of the difference between the two AVHRR thermal infrared channels is compared with the in situ measurements. While the quadratic formulation provides a considerable improvement over the older cross product (CPSST) and multichannel (MCSST) algorithms, the SSM/I corrected SST (called the water vapor or WVSST) shows overall smaller errors when compared to both the skin and bulk in situ SST observations. Applied to individual AVHRR images, the WVSST reveals an SST difference pattern (CPSST-WVSST) similar in shape to the water vapor structure while the CPSST-quadratic SST difference appears unrelated in pattern to the nearly coincident water vapor pattern. An application of the WVSST to week-long composites of global area coverage (GAC) AVHRR data demonstrates again the manner in which the WVSST corrects the AVHRR for atmospheric moisture attenuation. By comparison the quadratic SST method underestimates the SST corrections in the lower latitudes and overestimates the SST in th e higher latitudes. Correlations between the AVHRR thermal channel differences and the SSM/I water vapor demonstrate the inability of the channel difference to represent water vapor in the midlatitude and high latitudes during summer. Compared against drifting buoy data the WVSST and the quadratic SST both exhibit the same general behavior with the relatively small differences with the buoy temperatures.

A 20 year independent record of sea surface temperature for climate from Along-Track Scanning Radiometers

NASA Astrophysics Data System (ADS)

Merchant, Christopher J.; Embury, Owen; Rayner, Nick A.; Berry, David I.; Corlett, Gary K.; Lean, Katie; Veal, Karen L.; Kent, Elizabeth C.; Llewellyn-Jones, David T.; Remedios, John J.; Saunders, Roger

2012-12-01

A new record of sea surface temperature (SST) for climate applications is described. This record provides independent corroboration of global variations estimated from SST measurements made in situ. Infrared imagery from Along-Track Scanning Radiometers (ATSRs) is used to create a 20 year time series of SST at 0.1° latitude-longitude resolution, in the ATSR Reprocessing for Climate (ARC) project. A very high degree of independence of in situ measurements is achieved via physics-based techniques. Skin SST and SST estimated for 20 cm depth are provided, with grid cell uncertainty estimates. Comparison with in situ data sets establishes that ARC SSTs generally have bias of order 0.1 K or smaller. The precision of the ARC SSTs is 0.14 K during 2003 to 2009, from three-way error analysis. Over the period 1994 to 2010, ARC SSTs are stable, with better than 95% confidence, to within 0.005 K yr-1(demonstrated for tropical regions). The data set appears useful for cleanly quantifying interannual variability in SST and major SST anomalies. The ARC SST global anomaly time series is compared to the in situ-based Hadley Centre SST data set version 3 (HadSST3). Within known uncertainties in bias adjustments applied to in situ measurements, the independent ARC record and HadSST3 present the same variations in global marine temperature since 1996. Since the in situ observing system evolved significantly in its mix of measurement platforms and techniques over this period, ARC SSTs provide an important corroboration that HadSST3 accurately represents recent variability and change in this essential climate variable.

The Dependence of Cloud-SST Feedback on Circulation Regime and Timescale

NASA Astrophysics Data System (ADS)

Middlemas, E.; Clement, A. C.; Medeiros, B.

2017-12-01

Studies suggest cloud radiative feedback amplifies internal variability of Pacific sea surface temperature (SST) on interannual-and-longer timescales, though only a few modeling studies have tested the quantitative importance of this feedback (Bellomo et al. 2014b, Brown et al. 2016, Radel et al. 2016 Burgman et al. 2017). We prescribe clouds from a previous control run in the radiation module in Community Atmospheric Model (CAM5-slab), a method called "cloud-locking". By comparing this run to a control run, in which cloud radiative forcing can feedback on the climate system, we isolate the effect of cloud radiative forcing on SST variability. Cloud-locking prevents clouds from radiatively interacting with atmospheric circulation, water vapor, and SST, while maintaining a similar mean state to the control. On all timescales, cloud radiative forcing's influence on SST variance is modulated by the circulation regime. Cloud radiative forcing amplifies SST variance in subsiding regimes and dampens SST variance in convecting regimes. In this particular model, a tug of war between latent heat flux and cloud radiative forcing determines the variance of SST, and the winner depends on the timescale. On decadal-and-longer timescales, cloud radiative forcing plays a relatively larger role than on interannual-and-shorter timescales, while latent heat flux plays a smaller role. On longer timescales, the absence of cloud radiative feedback changes SST variance in a zonally asymmetric pattern in the Pacific Ocean that resembles an IPO-like pattern. We also present an analysis of cloud feedback's role on Pacific SST variability among preindustrial control CMIP5 models to test the model robustness of our results. Our results suggest that circulation plays a crucial role in cloud-SST feedbacks across the globe and cloud radiative feedbacks cannot be ignored when studying SST variability on decadal-and-longer timescales.

Moderate-resolution sea surface temperature data for the nearshore North Pacific

USGS Publications Warehouse

Payne, Meredith C.; Reusser, Deborah A.; Lee, Henry; Brown, Cheryl A.

2011-01-01

Coastal sea surface temperature (SST) is an important environmental characteristic in determining the suitability of habitat for nearshore marine and estuarine organisms. This publication describes and provides access to an easy-to-use coastal SST dataset for ecologists, biogeographers, oceanographers, and other scientists conducting research on nearshore marine habitats or processes. The data cover the Temperate Northern Pacific Ocean as defined by the 'Marine Ecosystems of the World' (MEOW) biogeographic schema developed by The Nature Conservancy. The spatial resolution of the SST data is 4-km grid cells within 20 km of the shore. The data span a 29-year period - from September 1981 to December 2009. These SST data were derived from Advanced Very High Resolution Radiometer (AVHRR) instrument measurements compiled into monthly means as part of the Pathfinder versions 5.0 and 5.1 (PFSST V50 and V51) Project. The processing methods used to transform the data from their native Hierarchical Data Format Scientific Data Set (HDF SDS) to georeferenced, spatial datasets capable of being read into geographic information systems (GIS) software are explained. In addition, links are provided to examples of scripts involved in the data processing steps. The scripts were written in the Python programming language, which is supported by ESRI's ArcGIS version 9 or later. The processed data files are also provided in text (.csv) and Access 2003 Database (.mdb) formats. All data except the raster files include attributes identifying realm, province, and ecoregion as defined by the MEOW classification schema.

Inter-decadal variation of the Tropical Atlantic-Korea (TA-K) teleconnection pattern during boreal summer season

NASA Astrophysics Data System (ADS)

Ham, Yoo-Geun; Hwang, YeonJi; Lim, Young-Kwon; Kwon, Minho

2017-12-01

The inter-decadal variation of the positive relationship between the tropical Atlantic sea surface temperature (SST) and Korean precipitation during boreal summer season during 1900-2010 is examined. The 15-year moving correlation between the Tropical Atlantic SST (TAtlSST) index (SST anomalies from 30°S to 30°N and 60°W to 20°E) and Korean precipitation (precipitation anomalies from 35°-40°N to 120°-130°E) during June-July-August exhibits strong inter-decadal variation, which becomes positive at the 95% confidence level after the 1980s. Intensification of the linkage between the TAtlSST index and Korean precipitation after the 1980s is attributed to global warming via the increased background SST. The increase in the background SST over the Atlantic provides background conditions that enhance anomalous convective activity by anomalous Atlantic SST warming. Therefore, the overall atmospheric responses associated with the tropical Atlantic SST warming could intensify. The correlation between the TAtlSST index and Korean precipitation also exhibits strong inter-decadal variation within 1980-2010, which is over 0.8 during early 2000s, while it is relative low (i.e., around 0.6) during the early 1980s. The enhanced co-variability between the tropical and the mid-latitude Atlantic SST during the early 2000s indicates the intensification of TAtlSST-related Rossby wave source over the mid-latitude Atlantic, which excites stationary waves propagated from the Atlantic to the Korean peninsula across northern Europe and northeast Asia. This Rossby-wave train induces a cyclonic flow over the northern edge of the Korea, which intensifies southwesterly and results in precipitation over Korea. This observed decadal difference is well simulated by the stationary wave model experiments with a prescribed TAtlSST-related Rossby wave source over the mid-latitude Atlantic.

The Oceanic Contribution to Atlantic Multi-Decadal Variability

NASA Astrophysics Data System (ADS)

Wills, R. C.; Armour, K.; Battisti, D. S.; Hartmann, D. L.

2017-12-01

Atlantic multi-decadal variability (AMV) is typically associated with variability in ocean heat transport (OHT) by the Atlantic Meridional Overturning Circulation (AMOC). However, recent work has cast doubt on this connection by showing that slab-ocean climate models, in which OHT cannot vary, exhibit similar variability. Here, we apply low-frequency component analysis to isolate the variability of Atlantic sea-surface temperatures (SSTs) that occurs on decadal and longer time scales. In observations and in pre-industrial control simulations of comprehensive climate models, we find that AMV is confined to the extratropics, with the strongest temperature anomalies in the North Atlantic subpolar gyre. We show that warm subpolar temperatures are associated with a strengthened AMOC, increased poleward OHT, and local heat fluxes from the ocean into the atmosphere. In contrast, the traditional index of AMV based on the basin-averaged SST anomaly shows warm temperatures preceded by heat fluxes from the atmosphere into the ocean, consistent with the atmosphere driving this variability, and shows a weak relationship with AMOC. The autocorrelation time of the basin-averaged SST index is 1 year compared to an autocorrelation time of 5 years for the variability of subpolar temperatures. This shows that multi-decadal variability of Atlantic SSTs is sustained by OHT variability associated with AMOC, while atmosphere-driven SST variability, such as exists in slab-ocean models, contributes primarily on interannual time scales.

Rising Mediterranean Sea Surface Temperatures Amplify Extreme Summer Precipitation in Central Europe

PubMed Central

Volosciuk, Claudia; Maraun, Douglas; Semenov, Vladimir A.; Tilinina, Natalia; Gulev, Sergey K.; Latif, Mojib

2016-01-01

The beginning of the 21st century was marked by a number of severe summer floods in Central Europe associated with extreme precipitation (e.g., Elbe 2002, Oder 2010 and Danube 2013). Extratropical storms, known as Vb-cyclones, cause summer extreme precipitation events over Central Europe and can thus lead to such floodings. Vb-cyclones develop over the Mediterranean Sea, which itself strongly warmed during recent decades. Here we investigate the influence of increased Mediterranean Sea surface temperature (SST) on extreme precipitation events in Central Europe. To this end, we carry out atmosphere model simulations forced by average Mediterranean SSTs during 1970–1999 and 2000–2012. Extreme precipitation events occurring on average every 20 summers in the warmer-SST-simulation (2000–2012) amplify along the Vb-cyclone track compared to those in the colder-SST-simulation (1970–1999), on average by 17% in Central Europe. The largest increase is located southeast of maximum precipitation for both simulated heavy events and historical Vb-events. The responsible physical mechanism is increased evaporation from and enhanced atmospheric moisture content over the Mediterranean Sea. The excess in precipitable water is transported from the Mediterranean Sea to Central Europe causing stronger precipitation extremes over that region. Our findings suggest that Mediterranean Sea surface warming amplifies Central European precipitation extremes. PMID:27573802

The Impact of High-Resolution Sea Surface Temperatures on the Simulated Nocturnal Florida Marine Boundary Layer

NASA Technical Reports Server (NTRS)

LaCasse, Katherine M.; Splitt, Michael E.; Lazarus, Steven M.; Lapenta, William M.

2008-01-01

High- and low-resolution sea surface temperature (SST) analysis products are used to initialize the Weather Research and Forecasting (WRF) Model for May 2004 for short-term forecasts over Florida and surrounding waters. Initial and boundary conditions for the simulations were provided by a combination of observations, large-scale model output, and analysis products. The impact of using a 1-km Moderate Resolution Imaging Spectroradiometer (MODIS) SST composite on subsequent evolution of the marine atmospheric boundary layer (MABL) is assessed through simulation comparisons and limited validation. Model results are presented for individual simulations, as well as for aggregates of easterly- and westerly-dominated low-level flows. The simulation comparisons show that the use of MODIS SST composites results in enhanced convergence zones. earlier and more intense horizontal convective rolls. and an increase in precipitation as well as a change in precipitation location. Validation of 10-m winds with buoys shows a slight improvement in wind speed. The most significant results of this study are that 1) vertical wind stress divergence and pressure gradient accelerations across the Florida Current region vary in importance as a function of flow direction and stability and 2) the warmer Florida Current in the MODIS product transports heat vertically and downwind of this heat source, modifying the thermal structure and the MABL wind field primarily through pressure gradient adjustments.

Coral-inferred Variability of Upstream Kuroshio Current from 1953-2004 AD

NASA Astrophysics Data System (ADS)

Li, X.; Yi, L.; Shen, C. C.; Hsin, Y. C.

2016-12-01

The Kuroshio Current (KC), one of the most important western boundary currents in the North Pacific Ocean, strongly impacts regional climate in East Asia and upper-ocean thermal structure. However, the responses of KC to regional and remote climate forcing are poorly understood owing to lacking of long-term KC observations. Here, we present a sea surface temperature (SST) record from 1953 to 2004 AD derived from monthly skeletal δ18O data of a living coral Porites core, drilled in Nanwan, southern Taiwan (22°N, 121°E), located on the western front of the Upstream KC. The increased/reduced Kuroshio transport would generate stronger/weaker upwelling in Southern Taiwan, which can cause lower/higher SST. Agreement between dynamics of interannual coral δ18O and modern KC data shows that the regional coral δ18O can be used as a promising proxy for Upstream KC intensity. The KC-induced SST anomaly record reveals prominent interannual and decadal variability predominantly controlled by the bifurcation latitude of North Equatorial Current. We also find that the reconstructed KC intensity at east of Taiwan and south of Japan have nearly simultaneous interannual changes, suggesting the same dominant forcing(s) for the entire KC system. Additional work is needed to understand the KC system with respect to the interannual to decadal climate variability and the influences of global warming.

Comparison of the Northeast Arctic cod year class strength (at the age of 3+) with the SST anomalies in main spawning ground (the Norwegian Shelf Waters) by results of analysis satellite monitoring data during last years.

NASA Astrophysics Data System (ADS)

Vanyushin, George

2015-04-01

Continuous long-term database (1998-2014) on the sea surface temperature (SST) comprising results of regional satellite monitoring (the Norwegian and the Barents seas) is used to resolve several applied problems. Authors have analyzed indirect influence the SST (the NOAA satellite data) on modern cod total stock biomass (abundance of the Northeast Arctic cod at age 3+). In this study, we went on the consideration of the relationship between the SST anomalies for March-April in the main spawning ground of the cod off the Lofoten islands in the Norwegian Shelf Waters and forecasting assessment of future cod generation success and its future abundance of 3 year old. Mean monthly SST and SST anomalies are computed for the selected area on the basis of the weekly SST maps which made by using the NOAA satellites data for the period 1998-2014. Comparison of the SST anomalies in the main spawning ground with abundance of the cod year class at age 3+ shows that survival of the cod generations was inhibited on the whole as negative (below -0,1C) well as positive SST anomalies (above +1,3C) during March and April. Finally, the results indicate that poor and low middle generations of cod at age 3+ (2002, 2004, 2010) occurred in years with negative or extremely high positive the SST anomalies in the spawning area. The SST anomalies in years which were close to normal significances provide conditions for appearance middle or strong generations of cod (2001-2003, 2005-2009, 2011-2013). So, the SST and SST anomalies (by the NOAA satellite data) characterize of increase in input of warm Atlantic waters which form numerous eddies along the main stream thus creating favorable conditions for spawning and development of the cod larvae and fry and provide them with food stock, finally direct influence on forming total stock biomass of cod and helping its population forecast. Key words: satellite monitoring of SST, the Northeast Arctic cod, spawning ground, forecast of the cod year class strength at age 3+.

Search for Trends and Periodicities in Inter-hemispheric Sea Surface Temperature Difference

NASA Astrophysics Data System (ADS)

Rajesh, R.; Tiwari, R. K.

2018-02-01

Understanding the role of coupled solar and internal ocean dynamics on hemispheric climate variability is critical to climate modelling. We have analysed here 165 year long annual northern hemispheric (NH) and southern hemispheric (SH) sea surface temperature (SST) data employing spectral and statistical techniques to identify the imprints of solar and ocean-atmospheric processes, if any. We reconstructed the eigen modes of NH-SST and SH-SST to reveal non-linear oscillations superimposed on the monotonic trend. Our analysis reveals that the first eigen mode of NH-SST and SH-SST representing long-term trend of SST variability accounts for 15-23% variance. Interestingly, these components are matching with first eigen mode (99% variance) of the total solar irradiance (TSI) suggesting possible impact of solar activity on long-term SST variation. Furthermore, spectral analysis of SSA reconstructed signal revealed statistically significant periodicities of 63 ± 5, 22 ± 2, 10 ± 1, 7.6, 6.3, 5.2, 4.7, and 4.2 years in both NH-SST and SH-SST data. The major harmonics centred at 63 ± 5, 22 ± 2, and 10 ± 1 years are similar to solar periodicities and hence may represent solar forcing, while the components peaking at around 7.6, 6.3, 5.2, 4.7, and 4.2 years apparently falls in the frequency bands of El-Nino-Southern Oscillations linked to the oceanic internal processes. Our analyses also suggest evidence for the amplitude modulation of 9-11 and 21-22 year solar cycles, respectively, by 104 and 163 years in northern and southern hemispheric SST data. The absence of the above periodic oscillations in CO2 fails to suggest its role on observed inter-hemispheric SST difference. The cross-plot analysis also revealed strong influence of solar activity on linear trend of NH- and SH-SST in addition to small contribution from CO2. Our study concludes that (1) the long-term trends in northern and southern hemispheric SST variability show considerable synchronicity with cyclic warming and cooling phases and (2) the difference in cyclic forcing and non-linear modulations stemming from solar variability as a possible source of hemispheric SST differences.

Identification of the receptors for somatostatin (SST) and cortistatin (CST) in chickens and investigation of the roles of cSST28, cSST14, and cCST14 in inhibiting cGHRH1-27NH2-induced growth hormone secretion in cultured chicken pituitary cells.

PubMed

Meng, Fengyan; Huang, Guian; Gao, Shunyu; Li, Juan; Yan, Zhenxin; Wang, Yajun

2014-03-25

Somatostatin receptors (SSTRs) are proposed to mediate the actions of somatostatin (SST) and its related peptide, cortistatin (CST), in vertebrates. However, the identity, functionality, and tissue expression of these receptors remain largely unknown in most non-mammalian vertebrates including birds. In this study, five SSTRs (named cSSTR1, cSSTR2, cSSTR3, cSSTR4, cSSTR5) were cloned from chicken brain by RT-PCR. Using a pGL3-CRE-luciferase reporter system, we demonstrated that activation of each cSSTR expressed in CHO cells by cSST28, cSST14 and cCST14 treatment could inhibit forskolin-induced luciferase activity of CHO cells, indicating the functional coupling of all cSSTRs to Gi protein(s). Interestingly, cSSTR1-4 expressed in CHO cells could be activated by cSST28, cSST14 and cCST14 with high potencies, suggesting that they may function as the receptors common for these peptides. In contrast, cSSTR5 could be potently activated by cSST28 only, indicating that it is a cSST28-specific receptor. Using RT-PCR, wide expression of cSSTRs was detected in chicken tissues including pituitary. In accordance with their expression in pituitary, cSST28, cSST14, and cCST14 were demonstrated to inhibit basal and novel cGHRH1-27NH2-induced GH secretion in cultured chicken pituitary cells dose-dependently (0-10nM) by Western blot analysis, suggesting the involvement of cSSTR(s) common for these peptides in mediating their inhibitory actions. Collectively, our study establishes a molecular basis to elucidate the roles of SST/CST in birds and provide insights into the roles of SST/CST in vertebrates, such as their conserved actions on pituitary. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Remotely-sensed sea surface temperatuares (SST) of Northeaster Pacific Coastal Zones

EPA Science Inventory

Sea surface temperature (SST) is an important indicator of long-term trends and geographical temperature patterns; however there have been relatively few long-term records of SST in near-coastal habitats. In situ SST measurements are irregular in both space and time. Therefore, w...

The contrasting response of Hadley circulation to different meridional structure of sea surface temperature in CMIP5

NASA Astrophysics Data System (ADS)

Feng, Juan; Li, Jianping; Zhu, Jianlei; Li, Yang; Li, Fei

2018-02-01

The response of the Hadley circulation (HC) to the sea surface temperature (SST) is determined by the meridional structure of SST and varies according to the changing nature of this meridional structure. The capability of the models from the phase 5 of the Coupled Model Intercomparison Project (CMIP5) is utilized to represent the contrast response of the HC to different meridional SST structures. To evaluate the responses, the variations of HC and SST were linearly decomposed into two components: the equatorially asymmetric (HEA for HC, and SEA for SST) and equatorially symmetric (HES for HC, and SES for SST) components. The result shows that the climatological features of HC and tropical SST (including the spatial structures and amplitude) are reasonably simulated in all the models. However, the response contrast of HC to different SST meridional structures shows uncertainties among models. This may be due to the fact that the long-term temporal variabilities of HEA, HES, and SEA are limited reproduced in the models, although the spatial structures of their long-term variabilities are relatively reasonably simulated. These results indicate that the performance of the CMIP5 models to simulate long-term temporal variability of different meridional SST structures and related HC variations plays a fundamental role in the successful reproduction of the response of HC to different meridional SST structures.

Sea Surface Temperature Records Using Sr/Ca Ratios in a Siderastrea siderea Coral from SE Cuba

NASA Astrophysics Data System (ADS)

Fargher, H. A.; Hughen, K. A.; Ossolinski, J. E.; Bretos, F.; Siciliano, D.; Gonzalez, P.

2015-12-01

Sea surface temperature (SST) variability from Cuba remains relatively unknown compared to the rest of the Caribbean. Cuba sits near an inflection point in the spatial pattern of SST from the North Atlantic Oscillation (NAO), and long SST records from the region could reveal changes in the influence of this climate system through time. A Siderastrea siderea coral from the Jardínes de la Reina in southern Cuba was drilled to obtain a 220 year long archive of environmental change. The genus Siderastrea has not been extensively studied as an SST archive, yet Sr/Ca ratios in the Cuban core show a clear seasonal signal and strong correlation to instrumental SST data (r2 = 0.86 and 0.36 for monthly and interannual (winter season) timescales, respectively). Annual growth rates (linear extension) of the coral are observed to have a minor influence on Sr/Ca variability, but do not show a direct correlation to SST on timescales from annual to multidecadal. Sr/Ca measurements from the Cuban coral are used to reconstruct monthly and seasonal (winter, summer) SST extending back more than two centuries. Wintertime SST in southern Cuba is compared to other coral Sr/Ca records of winter-season SST from locations sensitive to the NAO in order to investigate the stationarity of the NAO SST 'fingerprint' through time.

Research Pilot C. Gordon Fullerton in Cockpit of TU-144LL SST Flying Laboratory

NASA Technical Reports Server (NTRS)

1998-01-01

NASA Research pilot C. Gordon Fullerton sits in cockpit of TU-144LL SST Flying Laboratory. Fullerton was one of two NASA pilots who flew the aircraft as part of a joint high speed research program. NASA teamed with American and Russian aerospace industries for an extended period in a joint international research program featuring the Russian-built Tu-144LL supersonic aircraft. The object of the program was to develop technologies for a proposed future second-generation supersonic airliner to be developed in the 21st Century. The aircraft's initial flight phase began in June 1996 and concluded in February 1998 after 19 research flights. A shorter follow-on program involving seven flights began in September 1998 and concluded in April 1999. All flights were conducted in Russia from Tupolev's facility at the Zhukovsky Air Development Center near Moscow. The centerpiece of the research program was the Tu 144LL, a first-generation Russian supersonic jetliner that was modified by its developer/builder, Tupolev ANTK (aviatsionnyy nauchno-tekhnicheskiy kompleks-roughly, aviation technical complex), into a flying laboratory for supersonic research. Using the Tu-144LL to conduct flight research experiments, researchers compared full-scale supersonic aircraft flight data with results from models in wind tunnels, computer-aided techniques, and other flight tests. The experiments provided unique aerodynamic, structures, acoustics, and operating environment data on supersonic passenger aircraft. Data collected from the research program was being used to develop the technology base for a proposed future American-built supersonic jetliner. Although actual development of such an advanced supersonic transport (SST) is currently on hold, commercial aviation experts estimate that a market for up to 500 such aircraft could develop by the third decade of the 21st Century. The Tu-144LL used in the NASA-sponsored research program was a 'D' model with different engines than were used in production-model aircraft. Fifty experiments were proposed for the program and eight were selected, including six flight and two ground (engine) tests. The flight experiments included studies of the aircraft's exterior surface, internal structure, engine temperatures, boundary-layer airflow, the wing's ground-effect characteristics, interior and exterior noise, handling qualities in various flight profiles, and in-flight structural flexibility. The ground tests studied the effect of air inlet structures on airflow entering the engine and the effect on engine performance when supersonic shock waves rapidly change position in the engine air inlet. A second phase of testing further studied the original six in-flight experiments with additional instrumentation installed to assist in data acquisition and analysis. A new experiment aimed at measuring the in-flight deflections of the wing and fuselage was also conducted. American-supplied transducers and sensors were installed to measure nose boom pressures, angle of attack, and sideslip angles with increased accuracy. Two NASA pilots, Robert Rivers of Langley Research Center, Hampton, Virginia, and Gordon Fullerton from Dryden Flight Research Center, Edwards, California, assessed the aircraft's handling at subsonic and supersonic speeds during three flight tests in September 1998. The program concluded after four more data-collection flights in the spring of 1999. The Tu-144LL model had new Kuznetsov NK-321 turbofan engines rated at more than 55,000 pounds of thrust in full afterburner. The aircraft is 215 feet, 6 inches long and 42 feet, 2 inches high with a wingspan of 94 feet, 6 inches. The aircraft is constructed mostly of light aluminum alloy with titanium and stainless steel on the leading edges, elevons, rudder, and the under-surface of the rear fuselage.

Tropical Cyclone Genesis and Sudden Changes of Track and Intensity in the Western Pacific

DTIC Science & Technology

2008-09-30

North Atlantic . (Published in 2008) Our work on the effect of internally generated inner-core asymmetries on tropical cyclone potential intensity has...of the atmospheric circulation in TC basins to the global warming is more critical than increasing SST to understanding the impacts of global warming...Japan and its adjacent seas is studied with WRF model. The results suggest that the northward moisture transport through the outer cyclonic circulation

Variability of the Tropical Ocean Surface Temperatures at Decadal-Multidecadal Timescales. Part I: The Atlantic Ocean.

NASA Astrophysics Data System (ADS)

Mehta, Vikram M.

1998-09-01

Gridded time series from the Global Ocean Surface Temperature Atlas were analyzed with a variety of techniques to identify spatial structures and oscillation periods of the tropical Atlantic sea surface temperature (SST) variations at decadal timescales, and to develop physical interpretations of statistical patterns of decadal SST variations. Each time series was 110 yr (1882-1991) long. The tropical Atlantic SST variations were compared with decadal variations in a 74-yr-long (1912-85) north Nordeste Brazil rainfall time series and a 106-yr-long (1886-1991) tropical Atlantic cyclone activity index time series. The tropical Atlantic SST variations were also compared with decadal variations in the extratropical Atlantic SST.Multiyear to multidecadal variations in the cross-equatorial dipole pattern identified as a dominant empirical pattern of the tropical Atlantic SST variations in earlier and present studies are shown to be variations in the approximately north-south gradient of SST anomalies. It is also shown that there was no dynamical-thermodynamical, dipole mode of SST variations during the analysis period. There was a distinct decadal timescale (12-13 yr) of SST variations in the tropical South Atlantic, whereas no distinct decadal timescale was found in the tropical North Atlantic SST variations. Approximately 80% of the coherent decadal variance in the cross-equatorial SST gradient was `explained' by coherent decadal oscillations in the tropical South Atlantic SSTs. There were three, possibly physical, modes of decadal variations in the tropical Atlantic SSTs during the analysis period. In the more energetic mode of the North Atlantic decadal SST variations, anomalies traveled into the tropical North Atlantic from the extratropical North Atlantic along the eastern boundary of the basin. The anomalies strengthened and resided in the tropical North Atlantic for several years, then frequently traveled northward into the mid-high-latitude North Atlantic along the western boundary of the basin, and completed a clockwise rotation around the North Atlantic basin. In the less energetic North Atlantic decadal mode, SST anomalies originated in the tropical-subtropical North Atlantic near the African coast, and traveled northwestward and southward. In the South Atlantic decadal SST mode, anomalies either developed in situ or traveled into the tropical South Atlantic from the subtropical South Atlantic along the eastern boundary of the basin. The anomalies strengthened and resided in the tropical South Atlantic for several years, then frequently traveled southward into the subtropical South Atlantic along the western boundary of the basin, and completed a counterclockwise rotation around the South Atlantic basin. These decadal modes were not a permanent feature of the tropical Atlantic SST variations. The tropical North and South Atlantic SST anomalies frequently extended across the equator. Uncorrelated alignments of decadal SST anomalies having opposite signs on two sides of the equator occasionally created the apperance of a dipole.Independent analyses of the north Nordeste Brazil rainfall showed physical consistency and high coherence with the cross-equatorial SST gradient oscillations at 12-13-yr period. The tropical Atlantic cyclone index showed physical consistency but moderate coherence with the tropical North Atlantic decadal SST variations. The quasi-regularity of the 12-13-yr oscillations in the cross-equatorial SST gradient may provide an opportunity for long lead-time, skillful predictions of climate anomalies in the tropical Atlantic sector.

An Estimate of Low-Cloud Feedbacks from Variations of Cloud Radiative and Physical Properties with Sea Surface Temperature on Interannual Time Scales

NASA Technical Reports Server (NTRS)

Eitzen, Zachary A.; Xu, Kuan-Man; Wong, Takmeng

2011-01-01

Simulations of climate change have yet to reach a consensus on the sign and magnitude of the changes in physical properties of marine boundary layer clouds. In this study, the authors analyze how cloud and radiative properties vary with SST anomaly in low-cloud regions, based on five years (March 2000 - February 2005) of Clouds and the Earth s Radiant Energy System (CERES) -- Terra monthly gridded data and matched European Centre for Medium-Range Weather Forecasts (ECMWF) meteorological reanalaysis data. In particular, this study focuses on the changes in cloud radiative effect, cloud fraction, and cloud optical depth with SST anomaly. The major findings are as follows. First, the low-cloud amount (-1.9% to -3.4% /K) and the logarithm of low-cloud optical depth (-0.085 to -0.100/K) tend to decrease while the net cloud radiative effect (3.86 W/m(exp 2)/ K) becomes less negative as SST anomalies increase. These results are broadly consistent with previous observational studies. Second, after the changes in cloud and radiative properties with SST anomaly are separated into dynamic, thermodynamic, and residual components, changes in the dynamic component (taken as the vertical velocity at 700 hPa) have relatively little effect on cloud and radiative properties. However, the estimated inversion strength decreases with increasing SST, accounting for a large portion of the measured decreases in cloud fraction and cloud optical depth. The residual positive change in net cloud radiative effect (1.48 W/m(exp 2)/ K) and small changes in low-cloud amount (-0.81% to 0.22% /K) and decrease in the logarithm of optical depth (-0.035 to -0.046/ K) with SST are interpreted as a positive cloud feedback, with cloud optical depth feedback being the dominant contributor. Last, the magnitudes of the residual changes differ greatly among the six low-cloud regions examined in this study, with the largest positive feedbacks (approximately 4 W/m(exp 2)/ K) in the southeast and northeast Atlantic regions and a slightly negative feedback (-0.2 W/m(exp 2)/ K) in the south-central Pacific region. Because the retrievals of cloud optical depth and/or cloud fraction are difficult in the presence of aerosols, the transport of heavy African continental aerosols may contribute to the large magnitudes of estimated cloud feedback in the two Atlantic regions.

The Role of Reversed Equatorial Zonal Transport in Terminating an ENSO Event

NASA Astrophysics Data System (ADS)

Chen, H. C.; Hu, Z. Z.; Huang, B.; Sui, C. H.

2016-02-01

In this study, we demonstrate that a sudden reversal of anomalous equatorial zonal current at the peaking ENSO phase triggers the rapid termination of an ENSO event. Throughout an ENSO cycle, the anomalous equatorial zonal current is strongly controlled by the concavity of the anomalous thermocline meridional structure near the equator. During the ENSO developing phase, the anomalous zonal current in the central and eastern Pacific generally enhances the ENSO growth through its zonal SST advection. In the mature phase of ENSO, however, the equatorial thermocline depth anomalies are reflected in the eastern Pacific and slowly propagate westward off the equator in both hemispheres. As a result, the concavity of the thermocline anomalies near the equator is reversed, i.e., the off-equatorial thermocline depth anomalies become higher than that on the equator for El Niño events and lower for La Niño events. This meridional change of thermocline structure reverses zonal transport rapidly in the central-to-eastern equatorial Pacific, which weakens the ENSO SST anomalies by reversed advection. More importantly, the reversed zonal mass transport weakens the existing zonal tilting of equatorial thermocline and suppresses the thermocline feedback. Both processes are concentrated in the eastern equatorial Pacific and can be effective on subseasonal time scales. These current reversal effects are built-in to the ENSO peak phase and independent of the zonal wind effect on thermocline slope. It functions as an oceanic control on ENSO evolution during both El Niño and La Niña events.

Engine non-containment: UK risk assessment methods

NASA Technical Reports Server (NTRS)

Wallin, J. C.

1977-01-01

More realistic guideline data must be developed for use in aircraft design in order to comply with recent changes in British civil airworthiness requirements. Unrealistically pessimistic results were obtained when the methodology developed during the Concorde SST certification program was extended to assess catastrophic risks resulting from uncontained engine rotors.

20171003 - Exposure Research in EPA’s Chemical Safety for Sustainability Research Program (ACC LRI SST Science Discussion)

EPA Science Inventory

Estimates of human and ecological exposures are required as critical input to risk-based prioritization and screening of chemicals. This project seeks to develop the data, tools, and evaluation approaches required to generate rapid and scientifically-defensible exposure predictio...

Gas Fuelling System for SST-1Tokamak

NASA Astrophysics Data System (ADS)

Dhanani, Kalpesh; Raval, D. C.; Khan, Ziauddin; Semwal, Pratibha; George, Siju; Paravastu, Yuvakiran; Thankey, Prashant; Khan, M. S.; Pradhan, Subrata

2017-04-01

SST-1 Tokamak, the first Indian Steady-state Superconducting experimental device is at present under operation in the Institute for Plasma Research. For plasma break down & initiation, piezoelectric valve based gas feed system is implemented as a primary requirement due to its precise control, easy handling, low construction and maintenance cost and its flexibility in the selection of the working gas. Hydrogen gas feeding with piezoelectric valve is used in the SST-1 plasma experiments. The piezoelectric valves used in SST-1 are remotely driven by a PXI based platform and are calibrated before each SST-1 plasma operation with precise control. This paper will present the technical development and the results of the gas fuelling system of SST-1.

Coral Records of 20th Century Central Tropical Pacific SST and Salinity: Signatures of Natural and Anthropogenic Climate Change

NASA Astrophysics Data System (ADS)

Nurhati, I. S.; Cobb, K.; Di Lorenzo, E.

2011-12-01

Accurate forecasts of regional climate changes in many regions of the world largely depend on quantifying anthropogenic trends in tropical Pacific climate against its rich background of interannual to decadal-scale climate variability. However, the strong natural climate variability combined with limited instrumental climate datasets have obscured potential anthropogenic climate signals in the region. Here, we present coral-based sea-surface temperature (SST) and salinity proxy records over the 20th century (1898-1998) from the central tropical Pacific - a region sensitive to El Niño-Southern Oscillation (ENSO) whose variability strongly impacts the global climate. The SST and salinity proxy records are reconstructed via coral Sr/Ca and the oxygen isotopic composition of seawater (δ18Osw), respectively. On interannual (2-7yr) timescales, the SST proxy record tracks both eastern- and central-Pacific flavors of ENSO variability (R=0.65 and R=0.67, respectively). Interannual-scale salinity variability in our coral record highlights profound differences in precipitation and ocean advections during the two flavors of ENSO. On decadal (8yr-lowpassed) timescales, the central tropical Pacific SST and salinity proxy records are controlled by different sets of dynamics linked to the leading climate modes of North Pacific climate variability. Decadal-scale central tropical Pacific SST is highly correlated to the recently discovered North Pacific Gyre Oscillation (NPGO; R=-0.85), reflecting strong dynamical links between the central Pacific warming mode and extratropical decadal climate variability. Whereas decadal-scale salinity variations in the central tropical Pacific are significantly correlated with the Pacific Decadal Oscillation (PDO; R=0.54), providing a better understanding on low-frequency salinity variability in the region. Having characterized natural climate variability in this region, the coral record shows a +0.5°C warming trend throughout the last century. However, the most prominent feature of the new coral records is an unprecedented freshening trend since the mid-20th century, in line with global climate models (GCMs) projections of enhanced hydrological patterns (wet areas are getting wetter and vice versa) under greenhouse forcing. Taken together, the coral records provide key constraints on tropical Pacific climate trends that may improve regional climate projections in areas affected by tropical Pacific climate variability.
Central Tropical Pacific SST and Salinity Proxy Records

Mid-Piacenzian Variability of Nordic Seas Surface Circulation Linked to Terrestrial Climatic Change in Norway

NASA Astrophysics Data System (ADS)

Panitz, Sina; De Schepper, Stijn; Salzmann, Ulrich; Bachem, Paul E.; Risebrobakken, Bjørg; Clotten, Caroline; Hocking, Emma P.

2017-12-01

During the mid-Piacenzian, Nordic Seas sea surface temperatures (SSTs) were higher than today. While SSTs provide crucial climatic information, on their own they do not allow a reconstruction of potential underlying changes in water masses and currents. A new dinoflagellate cyst record for Ocean Drilling Program (ODP) Site 642 is presented to evaluate changes in northward heat transport via the Norwegian Atlantic Current (NwAC) between 3.320 and 3.137 Ma. The record is compared with vegetation and SST reconstructions from Site 642 and SSTs from Iceland Sea ODP Site 907 to identify links between SSTs, ocean currents, and vegetation changes. The dinocyst record shows that strong Atlantic water influence via the NwAC corresponds to higher-than-present SSTs and cool temperate vegetation during Marine Isotope Stage (MIS) transition M2-M1 and KM5. Reduced Atlantic water inflow relative to the warm stages coincides with near-modern SSTs and boreal vegetation during MIS M2, KM6, and KM4-KM2. During most of the studied interval, a strong SST gradient between Sites 642 and 907 indicates the presence of a proto-Arctic Front (AF). An absent gradient during the first half of MIS KM6, due to reduced Atlantic water influence at Site 642 and warm, presumably Atlantic water reaching Site 907, is indicative of a weakened NwAC and East Greenland Current. We conclude that repeated changes in Atlantic water influence directly affect terrestrial climate and that an active NwAC is needed for an AF to develop. Obliquity forcing may have played a role, but the correlation is not consistent.

Indian Ocean corals reveal crucial role of World War II bias for twentieth century warming estimates.

PubMed

Pfeiffer, M; Zinke, J; Dullo, W-C; Garbe-Schönberg, D; Latif, M; Weber, M E

2017-10-31

The western Indian Ocean has been warming faster than any other tropical ocean during the 20 th century, and is the largest contributor to the global mean sea surface temperature (SST) rise. However, the temporal pattern of Indian Ocean warming is poorly constrained and depends on the historical SST product. As all SST products are derived from the International Comprehensive Ocean-Atmosphere dataset (ICOADS), it is challenging to evaluate which product is superior. Here, we present a new, independent SST reconstruction from a set of Porites coral geochemical records from the western Indian Ocean. Our coral reconstruction shows that the World War II bias in the historical sea surface temperature record is the main reason for the differences between the SST products, and affects western Indian Ocean and global mean temperature trends. The 20 th century Indian Ocean warming pattern portrayed by the corals is consistent with the SST product from the Hadley Centre (HadSST3), and suggests that the latter should be used in climate studies that include Indian Ocean SSTs. Our data shows that multi-core coral temperature reconstructions help to evaluate the SST products. Proxy records can provide estimates of 20 th century SST that are truly independent from the ICOADS data base.

Increased serum concentrations of soluble ST2 predict mortality after burn injury.

PubMed

Hacker, Stefan; Dieplinger, Benjamin; Werba, Gregor; Nickl, Stefanie; Roth, Georg A; Krenn, Claus G; Mueller, Thomas; Ankersmit, Hendrik J; Haider, Thomas

2018-06-27

Large burn injuries induce a systemic response in affected patients. Soluble ST2 (sST2) acts as a decoy receptor for interleukin-33 (IL-33) and has immunosuppressive effects. sST2 has been described previously as a prognostic serum marker. Our aim was to evaluate serum concentrations of sST2 and IL-33 after thermal injury and elucidate whether sST2 is associated with mortality in these patients. We included 32 burn patients (total body surface area [TBSA] >10%) admitted to our burn intensive care unit and compared them to eight healthy probands. Serum concentrations of sST2 and IL-33 were measured serially using an enzyme-linked immunosorbent assay (ELISA) technique. The mean TBSA was 32.5%±19.6%. Six patients (18.8%) died during the hospital stay. Serum analyses showed significantly increased concentrations of sST2 and reduced concentrations of IL-33 in burn patients compared to healthy controls. In our study cohort, higher serum concentrations of sST2 were a strong independent predictor of mortality. Burn injuries cause an increment of sST2 serum concentrations with a concomitant reduction of IL-33. Higher concentrations of sST2 are associated with increased in-hospital mortality in burn patients.

The Transition of High-Resolution NASA MODIS Sea Surface Temperatures into the WRF Environmental Modeling System

NASA Technical Reports Server (NTRS)

Case, Jonathan L.; Jedlove, Gary J.; Santos, Pablo; Medlin, Jeffrey M.; Rozumalski, Robert A.

2009-01-01

The NASA Short-term Prediction Research and Transition (SPoRT) Center has developed a Moderate Resolution Imaging Spectroradiometer (MODIS) sea surface temperature (SST) composite at 2-km resolution that has been implemented in version 3 of the National Weather Service (NWS) Weather Research and Forecasting (WRF) Environmental Modeling System (EMS). The WRF EMS is a complete, full physics numerical weather prediction package that incorporates dynamical cores from both the Advanced Research WRF (ARW) and the Non-hydrostatic Mesoscale Model (NMM). The installation, configuration, and execution of either the ARW or NMM models is greatly simplified by the WRF EMS to encourage its use by NWS Weather Forecast Offices (WFOs) and the university community. The WRF EMS is easy to run on most Linux workstations and clusters without the need for compilers. Version 3 of the WRF EMS contains the most recent public release of the WRF-NMM and ARW modeling system (version 3 of the ARW is described in Skamarock et al. 2008), the WRF Pre-processing System (WPS) utilities, and the WRF Post-Processing program. The system is developed and maintained by the NWS National Science Operations Officer Science and Training Resource Coordinator. To initialize the WRF EMS with high-resolution MODIS SSTs, SPoRT developed the composite product consisting of MODIS SSTs over oceans and large lakes with the NCEP Real-Time Global (RTG) filling data over land points. Filling the land points is required due to minor inconsistencies between the WRF land-sea mask and that used to generate the MODIS SST composites. This methodology ensures a continuous field that adequately initializes all appropriate arrays in WRF. MODIS composites covering the Gulf of Mexico, western Atlantic Ocean and the Caribbean are generated daily at 0400, 0700, 1600, and 1900 UTC corresponding to overpass times of the NASA Aqua and Terra polar orbiting satellites. The MODIS SST product is output in gridded binary-1 (GRIB-1) data format for a seamless incorporation into WRF via the WPS utilities. The full-resolution, 1-km MODIS product is sub-sampled to 2-km grid spacing due to limitations in handling very large dimensions in the GRIB-1 data format. The GRIB-1 files are posted online at ftp://ftp.nsstc.org/sstcomp/WRF/, which is directly accessed by the WRF EMS scripts. The MODIS SST composites are also downloaded to the EMS data server, which is accessible by the WRF EMS users and NWS WFOs. The SPoRT MODIS SST composite provides the model with superior detail of the ocean gradients around Florida and surrounding waters, whereas the operational RTG SST typically depicts a relatively smooth field and is not able to capture sharp horizontal gradients in SST. Differences of 2-3 C are common over small horizontal distances, leading to enhanced SST gradients on either side of the Gulf Stream and along the edges of the cooler shelf waters. These sharper gradients can in turn produce atmospheric responses in simulated temperature and wind fields as depicted in LaCasse et al. Differences in atmospheric verification statistics over a several month study were generally small in the vicinity of south Florida; however, the validation of SSTs at specific buoy locations revealed important improvements in the biases and RMS errors, especially in the vicinity of the cooler shelf waters off the east-central Florida coast. A current weakness in the MODIS SST product is the occurrence of occasional discontinuities caused by high latency in SST coverage due to persistent cloud cover. An enhanced method developed by Jedlovec et al. (2009, GHRSST User Symposium) reduces the occurrence of these problems by adding Advanced Microwave Scanning Radiometer -- EOS (AMSR-E) SST data to the compositing process. Enhanced SST composites are produced over the ocean regions surrounding the Continental U.S. at four times each day corresponding to Terra and Aqua equator crossing times. For a given day and overpass time, both MODInd AMSR-E data from the previous seven days form a collection used in the compositing. At each MODIS pixel, cloud-free SST values from the collection are used to form a weighted average based on their latency (number of days from the current day). In this way, recent SST data are given more weight than older data. One of the primary issues involved in incorporating the AMSR-E microwave data in the composites is the tradeoff between the decreased spatial resolution of the AMSR-E data (25 km) and the increased coverage due to its near all-weather capability. Currently, the AMSR-E is given a weight of 20% compared to MODIS data, thereby preserving the spatial structure observed in the MODIS data. Day-time (night-time) AMSR-E SST data from Aqua are used with both Terra and Aqua MODIS day-time (night-time) SST data sets.

The 30-60-day Intraseasonal Variability of Sea Surface Temperature in the South China Sea dur1ing May-September

NASA Astrophysics Data System (ADS)

Mao, Jiangyu; Wang, Ming

2018-05-01

This study investigates the structure and propagation of intraseasonal sea surface temperature (SST) variability in the South China Sea (SCS) on the 30-60-day timescale during boreal summer (May-September). TRMM-based SST, GODAS oceanic reanalysis and ERA-Interim atmospheric reanalysis datasets from 1998 to 2013 are used to examine quantitatively the atmospheric thermodynamic and oceanic dynamic mechanisms responsible for its formation. Power spectra show that the 30-60-day SST variability is predominant, accounting for 60% of the variance of the 10-90-day variability over most of the SCS. Composite analyses demonstrate that the 30-60-day SST variability is characterized by the alternate occurrence of basin-wide positive and negative SST anomalies in the SCS, with positive (negative) SST anomalies accompanied by anomalous northeasterlies (southwesterlies). The transition and expansion of SST anomalies are driven by the monsoonal trough-ridge seesaw pattern that migrates northward from the equator to the northern SCS. Quantitative diagnosis of the composite mixed-layer heat budgets shows that, within a strong 30-60-day cycle, the atmospheric thermal forcing is indeed a dominant factor, with the mixed-layer net heat flux (MNHF) contributing around 60% of the total SST tendency, while vertical entrainment contributes more than 30%. However, the entrainment-induced SST tendency is sometimes as large as the MNHF-induced component, implying that ocean processes are sometimes as important as surface fluxes in generating the 30-60-day SST variability in the SCS.

Combined Effects of the North Atlantic Oscillation and the Arctic Oscillation on Sea Surface Temperature in the Alborán Sea

PubMed Central

Báez, José C.; Gimeno, Luis; Gómez-Gesteira, Moncho; Ferri-Yáñez, Francisco; Real, Raimundo

2013-01-01

We explored the possible effects of the North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) on interannual sea surface temperature (SST) variations in the Alborán Sea, both separately and combined. The probability of observing mean annual SST values higher than average was related to NAO and AO values of the previous year. The effect of NAO on SST was negative, while that of AO was positive. The pure effects of NAO and AO on SST are obscuring each other, due to the positive correlation between them. When decomposing SST, NAO and AO in seasonal values, we found that variation in mean annual SST and mean winter SST was significantly related to the mean autumn NAO of the previous year, while mean summer SST was related to mean autumn AO of the previous year. The one year delay in the effect of the NAO and AO on the SST could be partially related to the amount of accumulated snow, as we found a significant correlation between the total snow in the North Alborán watershed for a year with the annual average SST of the subsequent year. A positive AO implies a colder atmosphere in the Polar Regions, which could favour occasional cold waves over the Iberian Peninsula which, when coupled with precipitations favoured by a negative NAO, may result in snow precipitation. This snow may be accumulated in the high peaks and melt down in spring-summer of the following year, which consequently increases the runoff of freshwater to the sea, which in turn causes a diminution of sea surface salinity and density, and blocks the local upwelling of colder water, resulting in a higher SST. PMID:23638005

Variable School Start Times and Middle School Student's Sleep Health and Academic Performance.

PubMed

Lewin, Daniel S; Wang, Guanghai; Chen, Yao I; Skora, Elizabeth; Hoehn, Jessica; Baylor, Allison; Wang, Jichuan

2017-08-01

Improving sleep health among adolescents is a national health priority and implementing healthy school start times (SSTs) is an important strategy to achieve these goals. This study leveraged the differences in middle school SST in a large district to evaluate associations between SST, sleep health, and academic performance. This cross-sectional study draws data from a county-wide surveillance survey. Participants were three cohorts of eighth graders (n = 26,440). The school district is unique because SST ranged from 7:20 a.m. to 8:10 a.m. Path analysis and probit regression were used to analyze associations between SST and self-report measures of weekday sleep duration, grades, and homework controlling for demographic variables (sex, race, and socioeconomic status). The independent contributions of SST and sleep duration to academic performance were also analyzed. Earlier SST was associated with decreased sleep duration (χ 2  = 173, p < .0001) and deficient sleep (≤7 hours) among 45% of students. Students with SST before 7:45 a.m. were at increased risk of decreased sleep duration, academic performance, and academic effort. Path analysis models demonstrated the independent contributions of sleep duration, SST, and variable effects for demographic variables. This is the first study to evaluate the independent contributions of SST and sleep to academic performance in a large sample of middle school students. Deficient sleep was prevalent, and the earliest SST was associated with decrements in sleep and academics. These findings support the prioritization of policy initiatives to implement healthy SST for younger adolescents and highlight the importance of sleep health education disparities among race and gender groups. Copyright © 2017 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Selective central activation of somatostatin receptor 2 increases food intake, grooming behavior and rectal temperature in rats.

PubMed

Stengel, A; Goebel, M; Wang, L; Rivier, J; Kobelt, P; Monnikes, H; Tache, Y

2010-08-01

The consequences of selective activation of brain somatostatin receptor-2 (sst2) were assessed using the sst2 agonist, des-AA(1,4-6,11-13)-[DPhe(2),Aph7(Cbm),DTrp(8)]-Cbm-SST-Thr-NH2. Food intake (FI) was monitored in ad libitum fed rats chronically implanted with an intracerebroventricular (i.c.v.) cannula. The sst(2) agonist injected i.c.v. at 0.1 and 1 microg/rat dose-dependently increased light phase FI from 2 to 6 hours post injection (2.3+/-0.5 and 7.5+/-1.2 respectively vs. vehicle: 0.2+/-0.2 g/300 g bw, P<0.001). Peptide action was reversed by i.c.v. injection of the sst2 antagonist, des-AA(1,4-6,11-13)-[pNO(2)-Phe(2),DCys(3),Tyr(7),DAph(Cbm)8]-SST-2Nal-NH(2) and not reproduced by intraperitoneal injection (30 microg/rat). The sst(2) antagonist alone i.c.v. significantly decreased the cumulative 14-hours dark phase FI by 29.5%. Other behaviors, namely grooming, drinking and locomotor activity were also increased by the sst(2) agonist (1 microg/rat, i.c.v.) as monitored during the 2(nd) hour post injection while gastric emptying of solid food was unaltered. Rectal temperature rose 1 hour after the sst(2) agonist (1 microg/rat, i.c.v.) with a maximal response maintained from 1 to 4 hours post injection. These data show that selective activation of the brain sst(2) receptor induces a feeding response in the light phase not associated with changes in gastric emptying. The food intake reduction following sst(2) receptor blockade suggests a role of this receptor in the orexigenic drive during the dark phase.

Somatostatin Is Essential for the Sexual Dimorphism of GH Secretion, Corticosteroid-Binding Globulin Production, and Corticosterone Levels in Mice

PubMed Central

Adams, Jessica M.; Otero-Corchon, Veronica; Hammond, Geoffrey L.; Veldhuis, Johannes D.; Qi, Nathan

2015-01-01

Distinct male and female patterns of pituitary GH secretion produce sexually differentiated hepatic gene expression profiles, thereby influencing steroid and xenobiotic metabolism. We used a fully automated system to obtain serial nocturnal blood samples every 15 minutes from cannulated wild-type (WT) and somatostatin knockout (Sst-KO) mice to determine the role of SST, the principal inhibitor of GH release, in the generation of sexually dimorphic GH pulsatility. WT males had lower mean and median GH values, less random GH secretory bursts, and longer trough periods between GH pulses than WT females. Each of these parameters was feminized in male Sst-KO mice, whereas female Sst-KO mice had higher GH levels than all other groups, but GH pulsatility was unaffected. We next performed hepatic mRNA profiling with high-density microarrays. Male Sst-KO mice exhibited a globally feminized pattern of GH-dependent mRNA levels, but female Sst-KO mice were largely unaffected. Among the differentially expressed female-predominant genes was Serpina6, which encodes corticosteroid-binding globulin (CBG). Increased CBG was associated with elevated diurnal peak plasma corticosterone in unstressed WT females and both sexes of Sst-KO mice compared with WT males. Sst-KO mice also had exaggerated ACTH and corticosterone responses to acute restraint stress. However, consistent with their lack of phenotypic signs of excess glucocorticoids, cerebrospinal fluid concentrations of free corticosterone in Sst-KO mice were not elevated. In summary, SST is necessary for the prolonged interpulse troughs that define masculinized pituitary GH secretion. SST also contributes to sexual dimorphism of the hypothalamic-pituitary-adrenal axis via GH-dependent regulation of hepatic CBG production. PMID:25551181

Evaluation of somatostatin, CXCR4 chemokine and endothelin A receptor expression in a large set of paragangliomas.

PubMed

Kaemmerer, Daniel; Sänger, Jörg; Arsenic, Ruza; D'Haese, Jan G; Neumann, Jens; Schmitt-Graeff, Annette; Wirtz, Ralph Markus; Schulz, Stefan; Lupp, Amelie

2017-10-27

Paragangliomas are predominantly benign tumors, but in some cases invasive growth and also metastasis are observed. Given the limited number of nonsurgical treatment options, novel target structures for diagnostics and therapy of this tumor entity are urgently needed. In the present study, expression of all five somatostatin receptor (SST) subtypes, chemokine receptor CXCR4 and endothelin receptor type A (ETA) was assessed by means of immunohistochemistry in a total of 66 paraffin-embedded paraganglioma samples from 55 patients. The stainings were rated by means of the Immunoreactive Score and correlated to clinical data and to succinate dehydrogenase subunit B (SDHB) expression. SST2A was by far the most prominent receptor in the paragangliomas investigated. It was present in 89% of the tumors at a high intensity, followed by SST5, SST3, SST1 and SST4, which were detected in 47%, 35%, 35% and 13% of the samples, respectively. SDHB positive tumors exhibited significantly higher SST2A and SST3 expression as compared to SDHB negative cases. There was no correlation between SST and Ki-67 expression or grading of the tumors and no difference in SST expression between primary tumors and metastases. Cell surface expression of CXCR4 and ETA was detected only in few samples. On tumor capillaries, however, exceptionally strong staining for these two receptors was noticed in the vast majority of the tumors. In conclusion, paragangliomas are well suited for SST2A-based diagnostics and treatment modalities. An indirect targeting of these highly vascularized tumors via CXCR4 or ETA may also represent a promising future strategy.

Evaluation of somatostatin, CXCR4 chemokine and endothelin A receptor expression in a large set of paragangliomas

PubMed Central

Kaemmerer, Daniel; Sänger, Jörg; Arsenic, Ruza; D’Haese, Jan G.; Neumann, Jens; Schmitt-Graeff, Annette; Wirtz, Ralph Markus; Schulz, Stefan; Lupp, Amelie

2017-01-01

Paragangliomas are predominantly benign tumors, but in some cases invasive growth and also metastasis are observed. Given the limited number of nonsurgical treatment options, novel target structures for diagnostics and therapy of this tumor entity are urgently needed. In the present study, expression of all five somatostatin receptor (SST) subtypes, chemokine receptor CXCR4 and endothelin receptor type A (ETA) was assessed by means of immunohistochemistry in a total of 66 paraffin-embedded paraganglioma samples from 55 patients. The stainings were rated by means of the Immunoreactive Score and correlated to clinical data and to succinate dehydrogenase subunit B (SDHB) expression. SST2A was by far the most prominent receptor in the paragangliomas investigated. It was present in 89% of the tumors at a high intensity, followed by SST5, SST3, SST1 and SST4, which were detected in 47%, 35%, 35% and 13% of the samples, respectively. SDHB positive tumors exhibited significantly higher SST2A and SST3 expression as compared to SDHB negative cases. There was no correlation between SST and Ki-67 expression or grading of the tumors and no difference in SST expression between primary tumors and metastases. Cell surface expression of CXCR4 and ETA was detected only in few samples. On tumor capillaries, however, exceptionally strong staining for these two receptors was noticed in the vast majority of the tumors. In conclusion, paragangliomas are well suited for SST2A-based diagnostics and treatment modalities. An indirect targeting of these highly vascularized tumors via CXCR4 or ETA may also represent a promising future strategy. PMID:29163802

Understanding the effect of an excessive cold tongue bias on projecting the tropical Pacific SST warming pattern in CMIP5 models

NASA Astrophysics Data System (ADS)

Ying, Jun; Huang, Ping; Lian, Tao; Tan, Hongjian

2018-05-01

An excessive cold tongue is a common bias among current climate models, and considered an important source of bias in projections of tropical Pacific climate change under global warming. Specifically, the excessive cold tongue bias is closely related to the tropical Pacific SST warming (TPSW) pattern. In this study, we reveal that two processes are the critical mechanisms by which the excessive cold tongue bias influences the projection of the TPSW pattern, based on 32 models from phase 5 of Coupled Model Intercomparison Projection (CMIP5). On the one hand, by assuming that the shortwave (SW) radiation to SST feedback is linearly correlated to the cold tongue SST, the excessive cold tongue bias can induce an overly weak negative SW-SST feedback in the central Pacific, which can lead to a positive SST warming bias in the central to western Pacific (around 150°E-140°W). Moreover, the overly weak local atmospheric dynamics response to SST is a key process of the overly weak SW-SST feedback, compared with the cloud response to atmospheric dynamics and the SW radiation response to cloud. On the other hand, the overly strong ocean zonal overturning circulation associated with the excessive cold tongue bias results in an overestimation of the ocean dynamical thermostat effect, with enhanced ocean stratification under global warming, leading to a negative SST warming bias in the central and eastern Pacific (around 170°W-120°W). These two processes jointly form a positive SST warming bias in the western Pacific, contributing to a La Niña-like warming bias. Therefore, we suggest a more realistic climatological cold tongue SST is needed for a more reliable projection of the TPSW pattern.

CFD Computations for a Generic High-Lift Configuration Using TetrUSS

NASA Technical Reports Server (NTRS)

Pandya, Mohagna J.; Abdol-Hamid, Khaled S.; Parlette, Edward B.

2011-01-01

Assessment of the accuracy of computational results for a generic high-lift trapezoidal wing with a single slotted flap and slat is presented. The paper is closely aligned with the focus of the 1st AIAA CFD High Lift Prediction Workshop (HiLiftPW-1) which was to assess the accuracy of CFD methods for multi-element high-lift configurations. The unstructured grid Reynolds-Averaged Navier-Stokes solver TetrUSS/USM3D is used for the computational results. USM3D results are obtained assuming fully turbulent flow using the Spalart-Allmaras (SA) and Shear Stress Transport (SST) turbulence models. Computed solutions have been obtained at seven different angles-of-attack ranging from 6 -37 . Three grids providing progressively higher grid resolution are used to quantify the effect of grid resolution on the lift, drag, pitching moment, surface pressure and stall angle. SA results, as compared to SST results, exhibit better agreement with the measured data. However, both turbulence models under-predict upper surface pressures near the wing tip region.

Reynolds-Averaged Navier-Stokes Simulation of a 2D Circulation Control Wind Tunnel Experiment

NASA Technical Reports Server (NTRS)

Allan, Brian G.; Jones, Greg; Lin, John C.

2011-01-01

Numerical simulations are performed using a Reynolds-averaged Navier-Stokes (RANS) flow solver for a circulation control airfoil. 2D and 3D simulation results are compared to a circulation control wind tunnel test conducted at the NASA Langley Basic Aerodynamics Research Tunnel (BART). The RANS simulations are compared to a low blowing case with a jet momentum coefficient, C(sub u), of 0:047 and a higher blowing case of 0.115. Three dimensional simulations of the model and tunnel walls show wall effects on the lift and airfoil surface pressures. These wall effects include a 4% decrease of the midspan sectional lift for the C(sub u) 0.115 blowing condition. Simulations comparing the performance of the Spalart Allmaras (SA) and Shear Stress Transport (SST) turbulence models are also made, showing the SST model compares best to the experimental data. A Rotational/Curvature Correction (RCC) to the turbulence model is also evaluated demonstrating an improvement in the CFD predictions.

The Impact of Low-Level Cloud Feedback on Persistent Changes in Atmospheric Circulation in the Pacific

NASA Astrophysics Data System (ADS)

Burgman, R.; Kirtman, B. P.; Clement, A. C.; Vazquez, H.

2017-12-01

Recent studies suggest that low clouds in the Pacific play an important role in the observed decadal climate variability and future climate change. In this study, we implement a novel modeling experiment designed to isolate how interactions between local and remote feedbacks associated with low cloud, SSTs, and the largescale circulation play a significant role in the observed persistence of tropical Pacific SST and associated North American drought. The modeling approach involves the incorporation of observed patterns of satellite-derived shortwave cloud radiative effect (SWCRE) into the coupled model framework and is ideally suited for examining the role of local and large-scale coupled feedbacks and ocean heat transport in Pacific decadal variability. We show that changes in SWCRE forcing in eastern subtropical Pacific alone reproduces much of the observed changes in SST and atmospheric circulation over the past 16 years, including the observed changes in precipitation over much of the Western Hemisphere.

The group-based social skills training SOSTA-FRA in children and adolescents with high functioning autism spectrum disorder - study protocol of the randomised, multi-centre controlled SOSTA - net trial

PubMed Central

2013-01-01

Background Group-based social skills training (SST) has repeatedly been recommended as treatment of choice in high-functioning autism spectrum disorder (HFASD). To date, no sufficiently powered randomised controlled trial has been performed to establish efficacy and safety of SST in children and adolescents with HFASD. In this randomised, multi-centre, controlled trial with 220 children and adolescents with HFASD it is hypothesized, that add-on group-based SST using the 12 weeks manualised SOSTA–FRA program will result in improved social responsiveness (measured by the parent rated social responsiveness scale, SRS) compared to treatment as usual (TAU). It is further expected, that parent and self reported anxiety and depressive symptoms will decline and pro-social behaviour will increase in the treatment group. A neurophysiological study in the Frankfurt HFASD subgroup will be performed pre- and post treatment to assess changes in neural function induced by SST versus TAU. Methods/design The SOSTA – net trial is designed as a prospective, randomised, multi-centre, controlled trial with two parallel groups. The primary outcome is change in SRS score directly after the intervention and at 3 months follow-up. Several secondary outcome measures are also obtained. The target sample consists of 220 individuals with ASD, included at the six study centres. Discussion This study is currently one of the largest trials on SST in children and adolescents with HFASD worldwide. Compared to recent randomised controlled studies, our study shows several advantages with regard to in- and exclusion criteria, study methods, and the therapeutic approach chosen, which can be easily implemented in non-university-based clinical settings. Trial registration ISRCTN94863788 – SOSTA – net: Group-based social skills training in children and adolescents with high functioning autism spectrum disorder. PMID:23289935

Understanding the El Niño-like Oceanic Response in the Tropical Pacific to Global Warming

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, Yiyong; Lu, Jian; Liu, Fukai

The enhanced central and eastern Pacific SST warming and the associated ocean processes under global warming are investigated using the ocean component of the Community Earth System Model (CESM), Parallel Ocean Program version 2 (POP2). The tropical SST warming pattern in the coupled CESM can be faithfully reproduced by the POP2 forced with surface fluxes computed using the aerodynamic bulk formula. By prescribing the wind stress and/or wind speed through the bulk formula, the effects of wind stress change and/or the wind-evaporation-SST (WES) feedback are isolated and their linearity is evaluated in this ocean-alone setting. Result shows that, although themore » weakening of the equatorial easterlies contributes positively to the El Niño-like SST warming, 80% of which can be simulated by the POP2 without considering the effects of wind change in both mechanical and thermodynamic fluxes. This result points to the importance of the air-sea thermal interaction and the relative feebleness of the ocean dynamical process in the El Niño-like equatorial Pacific SST response to global warming. On the other hand, the wind stress change is found to play a dominant role in the oceanic response in the tropical Pacific, accounting for most of the changes in the equatorial ocean current system and thermal structures, including the weakening of the surface westward currents, the enhancement of the near-surface stratification and the shoaling of the equatorial thermocline. Interestingly, greenhouse gas warming in the absence of wind stress change and WES feedback also contributes substantially to the changes at the subsurface equatorial Pacific. Further, this warming impact can be largely replicated by an idealized ocean experiment forced by a uniform surface heat flux, whereby, arguably, a purest form of oceanic dynamical thermostat is revealed.« less

Hemispheric Symmetries of Plio-Pleistocene Surface Ocean Conditions: Insights from Southern Hemisphere ODP Sites 1125 and 1088

NASA Astrophysics Data System (ADS)

Lawrence, K. T.; Peterson, L.; Kelly, C.; Miller, H.; Seidenstein, J.

2013-12-01

For decades, most studies of Plio-Pleistocene climate and of the transition from the warmth of the Pliocene to the colder and more variable conditions of the Pleistocene have focused solely on northern hemisphere climate processes and responses. Here, we explore the southern hemisphere response to this major climate transition by documenting ocean surface conditions at Ocean Drilling Program Sites 1125 (42οS, 178οW, 1360m) and 1088 (40οS, 15οE, 2082m) through the Plio-Pleistocene. Secular trends in alkenone-derived sea surface temperature (SST) records indicate that these mid-latitude southern hemisphere sites cooled ~3-4οC over the past 3 Myrs, a magnitude comparable to sites located at similar latitudes in both the North Atlantic and North Pacific. This observation suggests that contraction of the low latitude warm pool was hemispherically symmetric. Our highly resolved (3 kyr resolution) Site 1125 SST record bears considerable structural similarity to SST records from nearby site 1123 (42οS,171οW) as well as sites 846 (3οS, 91οW) in the eastern equatorial Pacific and U1313 (41οN, 33οW) in the North Atlantic. Most of these SST records are dominated by 100k power and contain strong secondary 41k peaks throughout the past 3 million years. North Atlantic site U1313 is the exception, mirroring the shift in dominant periodicity from 41k to 100k associated with the mid-Pleistocene transition, that has long been observed in benthic oxygen isotope records. Finally, in southern hemisphere SST records as well as at site U1313 from the north Atlantic we observe weak precessional power that is not evident in benthic oxygen isotope record. These results suggest a fairly hemispherically-coordinated response of ocean surface temperature to changing global climate conditions during the Plio-Pleistocene in terms of both secular trends and dominant orbital frequencies.

Reconstructing Oceanographic Conditions From the Holocene to the Last Glacial Maximum in the Bay of Bengal

NASA Astrophysics Data System (ADS)

Miller, J.; Dekens, P. S.; Weber, M. E.; Spiess, V.; France-Lanord, C.

2015-12-01

The International Ocean Discovery Program (IODP) Expedition 354 drilled 7 sites in the Bay of Bengal, providing a unique opportunity to improve our understanding of the link between glacial cycles, tropical oceanographic changes, and monsoon strength. Deep-sea sediment cores of the Bengal Fan fluctuate between sand, hemipelagic and terrestrial sediment layers. All but one of the sites (U1454) contain a layer of calcareous clay in the uppermost part of the core that is late Pleistocene in age. During Expedition 354 site U1452C was sampled at high resolution (every 2cm) by a broad group of collaborators with the goal of reconstructing monsoon strength and oceanographic conditions using a variety of proxies. The top 480 cm of site U1452C (8ºN, 87ºE, 3671m water depth) contains primarily nannofossil rich calcareous clay. The relatively high abundance of foraminifera will allow us to generate a high resolution record of sea surface temperature (SST) and sea surface salinity (SSS) using standard foraminifera proxies. We will present oxygen isotopes (δ18O) and Mg/Ca data of mixed layer planktonic foraminifera from the top 70cm of the core, representing the Holocene to the last glacial maximum. δ18O of planktonic foraminifera records global ice volume and local SST and SSS, while Mg/Ca of foraminifera is a proxy for SST. The paired Mg/Ca and δ18O measurements on the same samples of foraminifera, together with published estimates with global ocean δ18O, can be used to reconstruct both SST and local δ18O of seawater, which is a function of the evaporation/precipitation balance. In future work, the local SSS and SST during the LGM will be paired with terrestrial and other oceanic proxies to increase our understanding of how global climate is connected to monsoon strength.

Simulation of Tropical Rainfall Variability

NASA Astrophysics Data System (ADS)

Bader, J.; Latif, M.

2002-12-01

The impact of sea surface temperature (SST) - especially the role of the tropical Atlantic meridional SST gradient and the El Nino-Southern Oscillation - on precipitation is investigated with the atmospheric general circulation model ECHAM4/T42. Ensemble experiments - driven with observed SST - show that Atlantic SST has a significant influence on precipitation over West Africa and northeast Brazil. SST sensitivity experiments were performed in which the climatological SST was enhanced or decreased by one Kelvin in certain ocean areas. Changing SST in the eastern tropical Atlantic caused only significant changes along the Guinea Coast, with a positive anomaly (SSTA) increasing rainfall and a negative SSTA reducing it. The response was nearly linear. Changing SST in other ocean areas caused significant changes over West Africa, especially in the Sahel area. The response is found to be non linear, with only negative SSTA leading to significant reduction in Sahel rainfall. Also, the impact of the SSTAs from the different ocean regions was not additive with respect to the rainfall. The influence of SST on precipitation over northeast Brazil (Nordeste) was also investigated. Three experiments were performed in which the climatological SST was enhanced/decreased or decreased/enhanced by one Kelvin in the North/South Atlantic and increased by two Kelvin in the Nino3 ocean area. All experiments caused significant changes over Nordeste, with an enhanced/reduced SST gradient in the Atlantic increasing/reducing rainfall. The response was nearly linear. The main effect of the Atlantic SST gradient was a shift of the ITCZ, caused by trade wind changes. The ''El Nino'' event generates a significant reduction in Nordeste rainfall. A significant positive SLP anomaly occurs in northeast Brazil which may be associated with the descending branch of the Walker circulation. Also a significant positive SLP over the Atlantic from 30S to 10N north occurs. This results in a reduced SLP gradient from the subtropical highs to the equator and a weakening of the trade winds.

Cross-sectional associations between maternal parenting styles, physical activity and screen sedentary time in children.

PubMed

Van der Geest, K E; Mérelle, S Y M; Rodenburg, G; Van de Mheen, D; Renders, C M

2017-09-29

Children's activity level, including physical activity (PA) and screen sedentary time (SST), is influenced by environmental factors in which parents play a critical role. Different types of parenting styles may influence children's activity level. Inconsistent results were found on the association between parenting styles and PA, and few studies tested the association between parenting styles and SST. This study examined the association between parenting styles, PA and SST and the modifying effect of children's gender and maternal educational level on these associations. Cross-sectional data were collected from parents of children aged 8-11 years old who completed a web-based non-standardized questionnaire (N = 4047). Since 85% of the questionnaires were filled in by mothers, parenting styles are mainly reported by mothers. Multiple linear regression techniques were used to assess the associations between parenting styles (authoritative, permissive, authoritarian and neglectful), and PA and SST (mean min/day). The modifying effect of children's gender and maternal educational level on these associations was explored. P values ≤.0125 were considered as statistically significant based on the Bonferroni correction for four primary analyses. The neglectful parenting style was most widely used (35.3%), while the authoritarian style was least common (14.8%). No significant association was found between parenting styles and PA level. As regards SST, an authoritative parenting style was significantly associated with lower SST in boys while a neglectful parenting style was significantly associated with higher SST in both boys and girls. When the mother had a medium educational level, an authoritative parenting style was significantly associated with lower SST while neglectful parenting was significantly associated with higher SST. No association was found between parenting styles and PA. However, an authoritative parenting style was associated with a reduction in SST and a neglectful parenting style with an increase in SST, especially in boys and in children whose mother had a medium education level. Future studies of parenting practices are needed to gain more insight into the role of parents in children's PA and SST levels, as a basis for the development of interventions tailored to support parents in stimulating PA and reducing SST in children.

Remote sensing of SST in the coastal ocean and inland seas

NASA Astrophysics Data System (ADS)

Kostianoy, Andrey

Sea Surface Temperature (SST) is the main oceanographic parameter widely used in oceanogra-phy that can be easily obtained from satellite measurements. Oceanic infrared remote sensing, based on the measurement of the thermal radiance emitted by the ocean, allows retrieving the SST corresponding to the temperature of the uppermost thin layer of the ocean. Theoretically the infrared signal only comes from the upper few microns "skin layer", therefore the thermal signatures cannot represent the dynamics of the mixed layer. But wind mixing during the daytime and nighttime convection mix the upper layer, so that SST usually is representative of that of the mixed layer. This is why nighttime passes of satellites are preferred for SST analysis. Since 1978 the Advanced Very High Resolution Radiometer (AVHRR), onboard the meteorolog-ical satellites of the NOAA series are widely used to derive SST maps. The temporal coverage is ensured by two-three NOAA satellites which provide 4-6 images/day over the globe with a swath of about 2800 km, the spatial resolution by a pixel of about 1.1 km, and thermal resolu-tion of about 0.1 deg. C. The typical data processing includes the retrieval of the SST from the combination of NN 3, 4, and 5 infrared channels of AVHRR, the geographical correction and localisation, with a generation of cloud and land masks. SST data can be then composed into daily to monthly (as well as season to yearly) maps/products. Moderate Resolution Imaging Spectroradiometer (MODIS)-Terra (since 2000) and -Aqua (since 2002), among the others, are the most known satellite instruments which increase the flow of the remote sensing SST data. In the regions with almost permanent cloudy conditions passive microwave radiometers are of vital importance for SST measurements, but they have significantly low spatial (25 km) and thermal (0.8 deg. C) resolution. Today, SST images/data are routinely acquired by satellite receiving stations worldwide including research vessels, as well as generated and made available via Internet by numerous world data centers for free. Examples of SST application for analy-sis/study/research/monitoring of SST fields, SST fronts, large-and meso-scale water dynamics and structure (currents, eddies, dipoles, jets, etc.), upwellings, SST seasonal and interannual variability, etc. will be shown. Combined analysis of SST data with optical (ocean color), SAR, altimetry, in-situ oceanographic, drifter and meteorological data was shown to be very successful for many purposes in physical oceanography, environment research and operational monitoring, regional and global climate change study, marine chemistry, marine biology and fishery. The presentation will include examples for different case studies in the Arctic Ocean (the Barents and Kara seas), the Atlantic Ocean (the Canary and Benguela upwellings), the Southern Indian Ocean, the Mediterranean, Black, Caspian, Aral, and Baltic seas.

Oceanic and atmospheric conditions associated with the pentad rainfall over the southeastern peninsular India during the North-East Indian Monsoon season

NASA Astrophysics Data System (ADS)

Shanmugasundaram, Jothiganesh; Lee, Eungul

2018-03-01

The association of North-East Indian Monsoon rainfall (NEIMR) over the southeastern peninsular India with the oceanic and atmospheric conditions over the adjacent ocean regions at pentad time step (five days period) was investigated during the months of October to December for the period 1985-2014. The non-parametric correlation and composite analyses were carried out for the simultaneous and lagged time steps (up to four lags) of oceanic and atmospheric variables with pentad NEIMR. The results indicated that NEIMR was significantly correlated: 1) positively with both sea surface temperature (SST) led by 1-4 pentads (lag 1-4 time steps) and latent heat flux (LHF) during the simultaneous, lag 1 and 2 time steps over the equatorial western Indian Ocean, 2) positively with SST but negatively with LHF (less heat flux from ocean to atmosphere) during the same and all the lagged time steps over the Bay of Bengal. Consistently, during the wet NEIMR pentads over the southeastern peninsular India, SST significantly increased over the Bay of Bengal during all the time steps and the equatorial western Indian Ocean during the lag 2-4 time steps, while the LHF decreased over the Bay of Bengal (all time steps) and increased over the Indian Ocean (same, lag 1 and 2). The investigation on ocean-atmospheric interaction revealed that the enhanced LHF over the equatorial western Indian Ocean was related to increased atmospheric moisture demand and increased wind speed, whereas the reduced LHF over the Bay of Bengal was associated with decreased atmospheric moisture demand and decreased wind speed. The vertically integrated moisture flux and moisture transport vectors from 1000 to 850 hPa exhibited that the moisture was carried away from the equatorial western Indian Ocean to the strong moisture convergence regions of the Bay of Bengal during the same and lag 1 time steps of wet NEIMR pentads. Further, the moisture over the Bay of Bengal was transported to the southeastern peninsular India through stronger cyclonic circulations, which were confirmed by the moisture transport vectors and positive vorticity. The identified ocean and atmosphere processes, associated with the wet NEIMR conditions, could be a valuable scientific input for enhancing the rainfall predictability, which has a huge socioeconomic value to agriculture and water resource management sectors in the southeastern peninsular India.

A dynamical stabilizer in the climate system: a mechanism suggested by a simple model

NASA Astrophysics Data System (ADS)

Bates, J. R.

1999-05-01

A simple zonally averaged hemispheric model of the climate system is constructed, based on energy equations for two ocean basins separated at 30° latitude with the surface fluxes calculated explicitly. A combination of empirical input and theoretical calculation is used to determine an annual mean equilibrium climate for the model and to study its stability with respect to small perturbations. The insolation, the mean albedos and the equilibrium temperatures for the two model zones are prescribed from observation. The principal agent of interaction between the zones is the vertically integrated poleward transport of atmospheric angular momentum across their common boundary. This is parameterized using an empirical formula derived from a multiyear atmospheric data set. The surface winds are derived from the angular momentum transport assuming the atmosphere to be in a state of dynamic balance on the climatic timescales of interest. A further assumption that the air sea temperature difference and low level relative humidity remain fixed at their mean observed values then allows the surface fluxes of latent and sensible heat to be calculated. Results from a radiative model, which show a positive lower tropospheric water vapour/infrared radiative feedback on SST perturbations in both zones, are used to calculate the net upward infrared radiative fluxes at the surface. In the model's equilibrium climate, the principal processes balancing the solar radiation absorbed at the surface are evaporation in the tropical zone and net infrared radiation in the extratropical zone. The stability of small perturbations about the equilibrium is studied using a linearized form of the ocean energy equations. Ice-albedo and cloud feedbacks are omitted and attention is focussed on the competing effects of the water vapour/infrared radiative feedback and the turbulent surface flux and oceanic heat transport feedbacks associated with the angular momentum cycle. The perturbation equations involve inter-zone coupling and have coefficients dependent on the values of the equilibrium fluxes and the sensitivity of the angular momentum transport. Analytical solutions for the perturbations are obtained. These provide criteria for the stability of the equilibrium climate. If the evaporative feedback on SST perturbations is omitted, the equilibrium climate is unstable due to the influence of the water vapour/infrared radiative feedback, which dominates over the effects of the sensible heat and ocean heat transport feedbacks. The inclusion of evaporation gives a negative feedback which is of sufficient strength to stabilize the system. The stabilizing mechanism involves wind and humidity factors in the evaporative fluxes that are of comparable magnitude. Both factors involve the angular momentum transport. In including angular momentum and calculating the surface fluxes explicitly, the model presented here differs from the many simple climate models based on the Budyko Sellers formulation. In that formulation, an atmospheric energy balance equation is used to eliminate surface fluxes in favour of top-of-the-atmosphere radiative fluxes and meridional atmospheric energy transports. In the resulting models, infrared radiation appears as a stabilizing influence on SST perturbations and the dynamical stabilizing mechanism found here cannot be identified.

Supersonic Cruise Research 1979, part 2. [airframe structures and materials, systems integration, economic analysis

NASA Technical Reports Server (NTRS)

1980-01-01

Advances in airframe structure and materials technology for supersonic cruise aircraft are reported with emphasis on titanium and composite structures. The operation of the Concorde is examined as a baseline for projections into the future. A market survey of U.S. passenger attitudes and preferences, the impact of advanced air transport technology and the integration of systems for the advanced SST and for a smaller research/business jet vehicle are also discussed.

Improved two-equation k-omega turbulence models for aerodynamic flows

NASA Technical Reports Server (NTRS)

Menter, Florian R.

1992-01-01

Two new versions of the k-omega two-equation turbulence model will be presented. The new Baseline (BSL) model is designed to give results similar to those of the original k-omega model of Wilcox, but without its strong dependency on arbitrary freestream values. The BSL model is identical to the Wilcox model in the inner 50 percent of the boundary-layer but changes gradually to the high Reynolds number Jones-Launder k-epsilon model (in a k-omega formulation) towards the boundary-layer edge. The new model is also virtually identical to the Jones-Lauder model for free shear layers. The second version of the model is called Shear-Stress Transport (SST) model. It is based on the BSL model, but has the additional ability to account for the transport of the principal shear stress in adverse pressure gradient boundary-layers. The model is based on Bradshaw's assumption that the principal shear stress is proportional to the turbulent kinetic energy, which is introduced into the definition of the eddy-viscosity. Both models are tested for a large number of different flowfields. The results of the BSL model are similar to those of the original k-omega model, but without the undesirable freestream dependency. The predictions of the SST model are also independent of the freestream values and show excellent agreement with experimental data for adverse pressure gradient boundary-layer flows.

The role of ocean-atmosphere interaction in Typhoon Sinlaku (2008) using a regional coupled data assimilation system

NASA Astrophysics Data System (ADS)

Wada, Akiyoshi; Kunii, Masaru

2017-05-01

For improving analyses of tropical cyclone (TC) and sea surface temperature (SST) and thereby TC simulations, a regional mesoscale strongly coupled atmosphere-ocean data assimilation system was developed with the local ensemble transform Kalman filter (LETKF) implemented with the Japan Meteorological Agency's nonhydrostatic model (NHM) coupled with a multilayer ocean model and the third-generation ocean wave model. The NHM-LETKF coupled data assimilation system was applied to Typhoon Sinlaku (2008) along with the original NHM-LETKF system to investigate the sensitivity of Sinlaku to SST assimilation with the Level 2 Pre-processed (L2P) standard product of satellite SST. SST calculated in the coupled-assimilation experiment with the coupled data assimilation system and the satellite SST (CPL) showed a better correlation with Optimally Interpolated SST than SST used in the control experiment with the original NHM-LETKF (CNTL) and SST calculated in the succession experiment with the coupled system without satellite SST (SUCC). The time series in the CPL experiment well captured the variation in the SST observed at the Kuroshio Extension Observation buoy site. In addition, TC-induced sea surface cooling was analyzed more realistically in the CPL experiment than that in the CNTL and SUCC experiments. However, the central pressure analyzed in each three experiments was overestimated compared with the Regional Specialized Meteorological Center Tokyo best-track central pressure, mainly due to the coarse horizontal resolution of 15 km. The 96 h TC simulations indicated that the CPL experiment provided more favorable initial and boundary conditions than the CNTL experiment to simulate TC tracks more accurately.

Somatostatin Signaling in Neuronal Cilia Is Criticalfor Object Recognition Memory

PubMed Central

Einstein, Emily B.; Patterson, Carlyn A.; Hon, Beverly J.; Regan, Kathleen A.; Reddi, Jyoti; Melnikoff, David E.; Mateer, Marcus J.; Schulz, Stefan; Johnson, Brian N.

2010-01-01

Most neurons possess a single, nonmotile cilium that projects out from the cell surface. These microtubule-based organelles are important in brain development and neurogenesis; however, their function in mature neurons is unknown. Cilia express a complement of proteins distinct from other neuronal compartments, one of which is the somatostatin receptor subtype SST3. We show here that SST3 is critical for object recognition memory in mice. sst3 knock-out mice are severely impaired in discriminating novel objects, whereas they retain normal memory for object location. Further, systemic injection of an SST3 antagonist (ACQ090) disrupts recall of familiar objects in wild-type mice. To examine mechanisms of SST3, we tested synaptic plasticity in CA1 hippocampus. Electrically evoked long-term potentiation (LTP) was normal in sst3 knock-out mice, while adenylyl cyclase/cAMP-mediated LTP was impaired. The SST3 antagonist also disrupted cAMP-mediated LTP. Basal cAMP levels in hippocampal lysate were reduced in sst3 knock-out mice compared with wild-type mice, while the forskolin-induced increase in cAMP levels was normal. The SST3 antagonist inhibited forskolin-stimulated cAMP increases, whereas the SST3 agonist L-796,778 increased basal cAMP levels in hippocampal slices but not hippocampal lysate. Our results show that somatostatin signaling in neuronal cilia is critical for recognition memory and suggest that the cAMP pathway is a conserved signaling motif in cilia. Neuronal cilia therefore represent a novel nonsynaptic compartment crucial for signaling involved in a specific form of synaptic plasticity and in novelty detection. PMID:20335466

A comparison of Argo nominal surface and near-surface temperature for validation of AMSR-E SST

NASA Astrophysics Data System (ADS)

Liu, Zenghong; Chen, Xingrong; Sun, Chaohui; Wu, Xiaofen; Lu, Shaolei

2017-05-01

Satellite SST (sea surface temperature) from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) is compared with in situ temperature observations from Argo profiling floats over the global oceans to evaluate the advantages of Argo NST (near-surface temperature: water temperature less than 1 m from the surface). By comparing Argo nominal surface temperature ( 5 m) with its NST, a diurnal cycle caused by daytime warming and nighttime cooling was found, along with a maximum warming of 0.08±0.36°C during 14:00-15:00 local time. Further comparisons between Argo 5-m temperature/Argo NST and AMSR-E SST retrievals related to wind speed, columnar water vapor, and columnar cloud water indicate warming biases at low wind speed (<5 m/s) and columnar water vapor >28 mm during daytime. The warming tendency is more remarkable for AMSR-E SST/Argo 5-m temperature compared with AMSR-E SST/Argo NST, owing to the effect of diurnal warming. This effect of diurnal warming events should be excluded before validation for microwave SST retrievals. Both AMSR-E nighttime SST/Argo 5-m temperature and nighttime SST/Argo NST show generally good agreement, independent of wind speed and columnar water vapor. From our analysis, Argo NST data demonstrated their advantages for validation of satellite-retrieved SST.

Long-Term Trends, Variability and Extremes of In Situ Sea Surface Temperature Measured Along the Eastern Adriatic Coast and its Relationship to Hemispheric Processes

NASA Astrophysics Data System (ADS)

Grbec, Branka; Matić, Frano; Beg Paklar, Gordana; Morović, Mira; Popović, Ružica; Vilibić, Ivica

2018-02-01

This paper examines long-term series of in situ sea surface temperature (SST) data measured at nine coastal and one open sea stations along the eastern Adriatic Sea for the period 1959-2015. Monthly and yearly averages were used to document SST trends and variability, while clustering and connections to hemispheric indices were achieved by applying the Principal Component Analysis (PCA) and Self-Organizing Maps (SOM) method. Both PCA and SOM revealed the dominance of temporal changes with respect to the effects of spatial differences in SST anomalies, indicating the prevalence of hemispheric processes over local dynamics, such as bora wind spatial inhomogeneity. SST extremes were connected with blocking atmospheric patterns. A substantial warming between 1979 and 2015, in total exceeding 1 °C, was preceded by a period with a negative SST trend, implying strong multidecadal variability in the Adriatic. The strongest connection was found between yearly SST and the East Atlantic (EA) pattern, while North Atlantic Oscillation (NAO) and East Atlantic/West Russia (EAWR) patterns were found to also affect February SST values. Quantification of the Adriatic SST and their connection to hemispheric indices allow for more precise projections of future SST, considered to be rather important for Adriatic thermohaline circulation, biogeochemistry and fisheries, and sensitive to ongoing climate change.

Possible relationship between East Indian Ocean SST and tropical cyclone affecting Korea

NASA Astrophysics Data System (ADS)

Kim, J. Y.; Choi, K. S.; Kim, B. J.

2014-12-01

In this study, a strong negative correlation was found between East Indian Ocean (EIO) SST and frequency of summertime tropical cyclone (TC) affecting Korea.For the Warm EIO SST years, the TCs mostly occurred in the southwestern region of tropical and subtropical western Pacific, and migrated west toward the southern coast of China and Indochinese peninsula through the South China Sea. This is because the anomalous easterlies, induced by the development of anomalous anticyclone (weakening of monsoon trough) from the tropical central Pacific to the southern coast of China, served as the steering flows for the westward migration of TCs. In contrast, for the cold EIO SST years, the TCs mostly occurred in the northeastern region of tropical and subtropical western Pacific, and migrated toward Korea and Japan located in the mid-latitudes of East Asia through the East China Sea. This is because the northeastward retreat of subtropical western North Pacific high (SWNPH) was more distinct for the cold EIO SST years compared to the warm EIO SST years. Therefore, the TCs of warm EIO SST years weakened or dissipated shortly due to the effect of geographical features as they land on the southern coast of China and Indochinese peninsula, whereas the TCs of cold EIO SST years had stronger intensity than the TCs of warm EIO SST years as sufficient energy is supplied from the ocean while moving toward Korea and Japan.

Sea surface temperature: Observations from geostationary satellites

NASA Astrophysics Data System (ADS)

Bates, John J.; Smith, William L.

1985-11-01

A procedure is developed for estimating sea surface temperatures (SST) from multispectral image data acquired from the VISSR atmospheric sounder (VAS) on the geostationary GOES satellites. Theoretical regression equations for two and three infrared window channels are empirically tuned by using clear field of view satellite radiances matched with reports of SST from NOAA fixed environmental buoys from 1982. The empirical regression equations are then used to produce daily regional analyses of SST. The daily analyses are used to study the response of SST's to the passage of Hurricane Alicia (1983) and Hurricane Debbie (1982) and are also used as a first guess surface temperature in the retrieval of atmospheric temperature and moisture profiles over the oceanic regions. Monthly mean SST's for the western North Atlantic and the eastern equatorial Pacific during March and July 1982 were produced for use in the NASA/JPL SST intercomparison workshop series. Workshop results showed VAS SST's have a scatter of 0.8°-1.0°C and a slight warm bias with respect to the other measurements of SST. Subsequently, a second set of VAS/ buoy matches collected during 1983 and 1984 was used to produce a set of bias corrected regression relations for VAS.

Multi-scale Quantitative Precipitation Forecasting Using ...

EPA Pesticide Factsheets

Global sea surface temperature (SST) anomalies can affect terrestrial precipitation via ocean-atmosphere interaction known as climate teleconnection. Non-stationary and non-linear characteristics of the ocean-atmosphere system make the identification of the teleconnection signals difficult to be detected at a local scale as it could cause large uncertainties when using linear correlation analysis only. This paper explores the relationship between global SST and terrestrial precipitation with respect to long-term non-stationary teleconnection signals during 1981-2010 over three regions in North America and one in Central America. Empirical mode decomposition as well as wavelet analysis is utilized to extract the intrinsic trend and the dominant oscillation of the SST and precipitation time series in sequence. After finding possible associations between the dominant oscillation of seasonal precipitation and global SST through lagged correlation analysis, the statistically significant SST regions are extracted based on the correlation coefficient. With these characterized associations, individual contribution of these SST forcing regions linked to the related precipitation responses are further quantified through nonlinear modeling with the aid of extreme learning machine. Results indicate that the non-leading SST regions also contribute a salient portion to the terrestrial precipitation variability compared to some known leading SST regions. In some cases, these

Skills training for pregnancy and AIDS prevention in Anglo and Latino youth.

PubMed

Hovell, M; Blumberg, E; Sipan, C; Hofstetter, C R; Burkham, S; Atkins, C; Felice, M

1998-09-01

This study tested social skills training (SST), didactic training (DT), and no training (NT) on adolescents' social skills for resisting peer pressure to engage in acquired immunodeficiency syndrome (AIDS) and pregnancy risk behavior. A total of 307 Latino and Anglo youth ages 13-18 years were assigned at random to receive 18 h of SST, 18 h of DT, or NT. Significantly (p < 0.05) greater increases in assertiveness followed SST compared to DT or NT for three trained skills: condom negotiation, asking a friend about their sex/drug history, and discussing a friend's risk of AIDS. Untrained negotiation skills (e.g., purchasing a condom) did not increase significantly. SST did not result in increased assertiveness for refusal skills. DT increased knowledge of AIDS significantly more than SST; both DT and SST increased knowledge significantly more than NT. Social skills training can increase assertiveness for certain negotiation skills that may decrease risk of AIDS for Latino, Anglo, and male and female adolescents. Both DT and SST can increase knowledge of AIDS prevention. Differences between experimental groups were supported by differences between trained and untrained skills within the SST condition, adding to discriminant validity.

Sea surface temperature 1871-2099 in 14 cells around the United Kingdom.

PubMed

Sheppard, Charles

2004-07-01

Monthly sea surface temperature is provided for 14 locations around the UK for a 230 year period. These series are derived from the HadISST1 data set for historical time (1871-1999) and from the HadCM3 climate model for predicted SST (1950-2099). Two adjustments of the forecast data sets are needed to produce confluent SST series: the 50 year overlap is used for a gross adjustment, and a statistical scaling on the forecast data ensures that annual variations in forecast data match those of historical data. These monthly SST series are available on request. The overall rise in SST over time is clear for all sites, commencing in the last quarter of the 20th century. Apart from expected trends of overall warmer mean SST with more southerly latitudes and overall cooler mean SST towards the East, more interesting statistically significant general trends include a greater decadal rate of rise from warmer starting conditions. Annual temperature variation is not affected by absolute temperature, but is markedly greater towards the East. There is no correlation of annual range of SST with latitude, or with present SST values.

The numerical modeling the sensitivity of coastal wind and ozone concentration to different SST forcing

NASA Astrophysics Data System (ADS)

Choi, Hyun-Jung; Lee, Hwa Woon; Jeon, Won-Bae; Lee, Soon-Hwan

2012-01-01

This study evaluated an atmospheric and air quality model of the spatial variability in low-level coastal winds and ozone concentration, which are affected by sea surface temperature (SST) forcing with different thermal gradients. Several numerical experiments examined the effect of sea surface SST forcing on the coastal atmosphere and air quality. In this study, the RAMS-CAMx model was used to estimate the sensitivity to two different resolutions of SST forcing during the episode day as well as to simulate the low-level coastal winds and ozone concentration over a complex coastal area. The regional model reproduced the qualitative effect of SST forcing and thermal gradients on the coastal flow. The high-resolution SST derived from NGSST-O (New Generation Sea Surface Temperature Open Ocean) forcing to resolve the warm SST appeared to enhance the mean response of low-level winds to coastal regions. These wind variations have important implications for coastal air quality. A higher ozone concentration was forecasted when SST data with a high resolution was used with the appropriate limitation of temperature, regional wind circulation, vertical mixing height and nocturnal boundary layer (NBL) near coastal areas.

Western tropical Pacific multidecadal variability forced by the Atlantic multidecadal oscillation

NASA Astrophysics Data System (ADS)

Kucharski, F.; Sun, C.; Li, J.; Jin, F. F.; Kang, I. S.; Ding, R.

2017-12-01

Observational analysis suggests that the western tropical Pacific (WTP) sea surface temperature (SST) shows predominant variability over multidecadal time scales, which is unlikely to be explained by the Interdecadal Pacific Oscillation. Here we show that this variability is largely explained by the remote Atlantic multidecadal oscillation (AMO). A suite of Atlantic Pacemaker experiments successfully reproduces the WTP multidecadal variability and the AMO-WTP SST connection. The AMO warm SST anomaly generates an atmospheric teleconnection to the North Pacific, which weakens the Aleutian low and subtropical North Pacific westerlies. The wind changes induce a subtropical North Pacific SST warming through wind-evaporation-SST effect, and in response to this warming, the surface winds converge towards the subtropical North Pacific from the tropics, leading to anomalous cyclonic circulation and low pressure over the WTP region. The warm SST anomaly further develops due to the SST-sea level pressure-cloud-longwave radiation positive feedback. Our findings suggest that the Atlantic Ocean acts as a key pacemaker for the western Pacific decadal climate variability.

Modulation of the adaptive response to stress by brain activation of selective somatostatin receptor subtypes.

PubMed

Stengel, Andreas; Rivier, Jean; Taché, Yvette

2013-04-01

Somatostatin-14 was discovered in 1973 in the hypothalamus as a peptide inhibiting growth hormone release. Somatostatin interacts with five receptor subtypes (sst(1-5)) which are widely distributed in the brain with a distinct, but overlapping, expression pattern. During the last few years, the development of highly selective peptide agonists and antagonists provided new insight to characterize the role of somatostatin receptor subtypes in the pleiotropic actions of somatostatin. Recent evidence in rodents indicates that the activation of selective somatostatin receptor subtypes in the brain blunts stress-corticotropin-releasing factor (CRF) related ACTH release (sst2/5), sympathetic-adrenal activaton (sst5), stimulation of colonic motility (sst1), delayed gastric emptying (sst5), suppression of food intake (sst2) and the anxiogenic-like (sst2) response. These findings suggest that brain somatostatin signaling pathways may play an important role in dampening CRF-mediated endocrine, sympathetic, behavioral and visceral responses to stress. Published by Elsevier Inc.

Relationship between Trends in Land Precipitation and Tropical SST Gradient

NASA Technical Reports Server (NTRS)

Chung, Chul Eddy; Ramanathan, V.

2007-01-01

In this study, we examined global zonal/annual mean precipitation trends. Land precipitation trend from 1951 to 2002 shows widespread drying between 10 S to 20 N but the trend from 1977 to 2002 shows partial recovery. Based on general circulation model sensitivity studies, we suggested that these features are driven largely by the meridional SST gradient trend in the tropics. Our idealized CCM3 experiments substantiated that land precipitation is more sensitive to meridional SST gradient than to an overall tropical warming. Various simulations produced for the IPCC 4th assessment report demonstrate that increasing CO2 increases SST in the entire tropics non-uniformly and increases land precipitation only in certain latitude belts, again pointing to the importance of SST gradient change. Temporally varying aerosols in the IPCC simulations alter meridional SST gradient and land precipitation substantially. Anthropogenic aerosol direct solar forcing without its effects on SST is shown by the CCM3 to have weak but non-negligible influence on land precipitation.

Western tropical Pacific multidecadal variability forced by the Atlantic multidecadal oscillation

NASA Astrophysics Data System (ADS)

Sun, Cheng; Kucharski, Fred; Li, Jianping; Jin, Fei-Fei; Kang, In-Sik; Ding, Ruiqiang

2017-07-01

Observational analysis suggests that the western tropical Pacific (WTP) sea surface temperature (SST) shows predominant variability over multidecadal time scales, which is unlikely to be explained by the Interdecadal Pacific Oscillation. Here we show that this variability is largely explained by the remote Atlantic multidecadal oscillation (AMO). A suite of Atlantic Pacemaker experiments successfully reproduces the WTP multidecadal variability and the AMO-WTP SST connection. The AMO warm SST anomaly generates an atmospheric teleconnection to the North Pacific, which weakens the Aleutian low and subtropical North Pacific westerlies. The wind changes induce a subtropical North Pacific SST warming through wind-evaporation-SST effect, and in response to this warming, the surface winds converge towards the subtropical North Pacific from the tropics, leading to anomalous cyclonic circulation and low pressure over the WTP region. The warm SST anomaly further develops due to the SST-sea level pressure-cloud-longwave radiation positive feedback. Our findings suggest that the Atlantic Ocean acts as a key pacemaker for the western Pacific decadal climate variability.

Ocean heat budget analysis on sea surface temperature anomaly in western Indian Ocean during strong-weak Asian summer monsoon

NASA Astrophysics Data System (ADS)

Fathrio, Ibnu; Manda, Atsuyoshi; Iizuka, Satoshi; Kodama, Yasu-Masa; Ishida, Sachinobu

2018-05-01

This study presents ocean heat budget analysis on seas surface temperature (SST) anomalies during strong-weak Asian summer monsoon (southwest monsoon). As discussed by previous studies, there was close relationship between variations of Asian summer monsoon and SST anomaly in western Indian Ocean. In this study we utilized ocean heat budget analysis to elucidate the dominant mechanism that is responsible for generating SST anomaly during weak-strong boreal summer monsoon. Our results showed ocean advection plays more important role to initate SST anomaly than the atmospheric prcess (surface heat flux). Scatterplot analysis showed that vertical advection initiated SST anomaly in western Arabian Sea and southwestern Indian Ocean, while zonal advection initiated SST anomaly in western equatorial Indian Ocean.

Predicting the spatiotemporal distributions of marine fish species utilizing earth system data in a maximum entropy modeling framework

NASA Astrophysics Data System (ADS)

Wang, L.; Kerr, L. A.; Bridger, E.

2016-12-01

Changes in species distributions have been widely associated with climate change. Understanding how ocean conditions influence marine fish distributions is critical for elucidating the role of climate in ecosystem change and forecasting how fish may be distributed in the future. Species distribution models (SDMs) can enable estimation of the likelihood of encountering species in space or time as a function of environmental conditions. Traditional SDMs are applied to scientific-survey data that include both presences and absences. Maximum entropy (MaxEnt) models are promising tools as they can be applied to presence-only data, such as those collected from fisheries or citizen science programs. We used MaxEnt to relate the occurrence records of marine fish species (e.g. Atlantic herring, Atlantic mackerel, and butterfish) from NOAA Northeast Fisheries Observer Program to environmental conditions. Environmental variables from earth system data, such as sea surface temperature (SST), sea bottom temperature (SBT), Chlorophyll-a, bathymetry, North Atlantic oscillation (NAO), and Atlantic multidecadal oscillation (AMO), were matched with species occurrence for MaxEnt modeling the fish distributions in Northeast Shelf area. We developed habitat suitability maps for these species, and assessed the relative influence of environmental factors on their distributions. Overall, SST and Chlorophyll-a had greatest influence on their monthly distributions, with bathymetry and SBT having moderate influence and climate indices (NAO and AMO) having little influence. Across months, Atlantic herring distribution was most related to SST 10th percentile, and Atlantic mackerel and butterfish distributions were most related to previous month SST. The fish distributions were most affected by previous month Chlorophyll-a in summer months, which may indirectly indicate the accumulative impact of primary productivity. Results highlighted the importance of spatial and temporal scales when using SDMs to investigate the habitat suitability and distributions of a focal species. MaxEnt models have the potential to provide hindcasts of where species might have been in the past in relation to historical environmental conditions, nowcasts in relation to current conditions, or forecasts of future species distributions.

Southern Ocean air-sea heat flux, SST spatial anomalies, and implications for multi-decadal upper ocean heat content trends.

NASA Astrophysics Data System (ADS)

Tamsitt, V. M.; Talley, L. D.; Mazloff, M. R.

2014-12-01

The Southern Ocean displays a zonal dipole (wavenumber one) pattern in sea surface temperature (SST), with a cool zonal anomaly in the Atlantic and Indian sectors and a warm zonal anomaly in the Pacific sector, associated with the large northward excursion of the Malvinas and southeastward flow of the Antarctic Circumpolar Current (ACC). To the north of the cool Indian sector is the warm, narrow Agulhas Return Current (ARC). Air-sea heat flux is largely the inverse of this SST pattern, with ocean heat gain in the Atlantic/Indian, cooling in the southeastward-flowing ARC, and cooling in the Pacific, based on adjusted fluxes from the Southern Ocean State Estimate (SOSE), a ⅙° eddy permitting model constrained to all available in situ data. This heat flux pattern is dominated by turbulent heat loss from the ocean (latent and sensible), proportional to perturbations in the difference between SST and surface air temperature, which are maintained by ocean advection. Locally in the Indian sector, intense heat loss along the ARC is contrasted by ocean heat gain of 0.11 PW south of the ARC. The IPCC AR5 50 year depth-averaged 0-700 m temperature trend shows surprising similarities in its spatial pattern, with upper ocean warming in the ARC contrasted by cooling to the south. Using diagnosed heat budget terms from the most recent (June 2014) 6-year run of the SOSE we find that surface cooling in the ARC is balanced by heating from south-eastward advection by the current whereas heat gain in the ACC is balanced by cooling due to northward Ekman transport driven by strong westerly winds. These results suggest that spatial patterns in multi-decadal upper ocean temperature trends depend on regional variations in upper ocean dynamics.

The ocean's role in polar climate change: asymmetric Arctic and Antarctic responses to greenhouse gas and ozone forcing

PubMed Central

Marshall, John; Armour, Kyle C.; Scott, Jeffery R.; Kostov, Yavor; Hausmann, Ute; Ferreira, David; Shepherd, Theodore G.; Bitz, Cecilia M.

2014-01-01

In recent decades, the Arctic has been warming and sea ice disappearing. By contrast, the Southern Ocean around Antarctica has been (mainly) cooling and sea-ice extent growing. We argue here that interhemispheric asymmetries in the mean ocean circulation, with sinking in the northern North Atlantic and upwelling around Antarctica, strongly influence the sea-surface temperature (SST) response to anthropogenic greenhouse gas (GHG) forcing, accelerating warming in the Arctic while delaying it in the Antarctic. Furthermore, while the amplitude of GHG forcing has been similar at the poles, significant ozone depletion only occurs over Antarctica. We suggest that the initial response of SST around Antarctica to ozone depletion is one of cooling and only later adds to the GHG-induced warming trend as upwelling of sub-surface warm water associated with stronger surface westerlies impacts surface properties. We organize our discussion around ‘climate response functions’ (CRFs), i.e. the response of the climate to ‘step’ changes in anthropogenic forcing in which GHG and/or ozone-hole forcing is abruptly turned on and the transient response of the climate revealed and studied. Convolutions of known or postulated GHG and ozone-hole forcing functions with their respective CRFs then yield the transient forced SST response (implied by linear response theory), providing a context for discussion of the differing warming/cooling trends in the Arctic and Antarctic. We speculate that the period through which we are now passing may be one in which the delayed warming of SST associated with GHG forcing around Antarctica is largely cancelled by the cooling effects associated with the ozone hole. By mid-century, however, ozone-hole effects may instead be adding to GHG warming around Antarctica but with diminished amplitude as the ozone hole heals. The Arctic, meanwhile, responding to GHG forcing but in a manner amplified by ocean heat transport, may continue to warm at an accelerating rate. PMID:24891392

Simulating the Cyclone Induced Turbulent Mixing in the Bay of Bengal using COAWST Model

NASA Astrophysics Data System (ADS)

Prakash, K. R.; Nigam, T.; Pant, V.

2017-12-01

Mixing in the upper oceanic layers (up to a few tens of meters from surface) is an important process to understand the evolution of sea surface properties. Enhanced mixing due to strong wind forcing at surface leads to deepening of mixed layer that affects the air-sea exchange of heat and momentum fluxes and modulates sea surface temperature (SST). In the present study, we used Coupled-Ocean-Atmosphere-Wave-Sediment Transport (COAWST) model to demonstrate and quantify the enhanced cyclone induced turbulent mixing in case of a severe cyclonic storm. The COAWST model was configured over the Bay of Bengal (BoB) and used to simulate the atmospheric and oceanic conditions prevailing during the tropical cyclone (TC) Phailin that occurred over the BoB during 10-15 October 2013. The model simulated cyclone track was validated with IMD best-track and model SST validated with daily AVHRR SST data. Validation shows that model simulated track & intensity, SST and salinity were in good agreement with observations and the cyclone induced cooling of the sea surface was well captured by the model. Model simulations show a considerable deepening (by 10-15 m) of the mixed layer and shoaling of thermocline during TC Phailin. The power spectrum analysis was performed on the zonal and meridional baroclinic current components, which shows strongest energy at 14 m depth. Model results were analyzed to investigate the non-uniform energy distribution in the water column from surface up to the thermocline depth. The rotary spectra analysis highlights the downward direction of turbulent mixing during the TC Phailin period. Model simulations were used to quantify and interpret the near-inertial mixing, which were generated by cyclone induced strong wind stress and the near-inertial energy. These near-inertial oscillations are responsible for the enhancement of the mixing operative in the strong post-monsoon (October-November) stratification in the BoB.

Seasonal variations in the nitrogen isotope composition of Okinotori coral in the tropical western Pacific: A new proxy for marine nitrate dynamics

NASA Astrophysics Data System (ADS)

Yamazaki, Atsuko; Watanabe, Tsuyoshi; Ogawa, Nanako O.; Ohkouchi, Naohiko; Shirai, Kotaro; Toratani, Mitsuhiro; Uematsu, Mitsuo

2011-12-01

To demonstrate the utility of coral skeletons as a recorder of nitrate dynamics in the surface ocean, we collected coral skeletons of Porites lobata and determined their nitrogen isotope composition (δ15Ncoral) from 2002 to 2006. Skeletons were collected at Okinotori Island in southwestern Japan, far from any sources of terrestrial nitrogen. Nitrogen isotope compositions along the growth direction were determined at 800 μm intervals (˜1 month resolution) and compared against the skeletal carbon isotope composition (δ13Ccoral-carb), barium/calcium ratio (Ba/Ca), and Chlorophyll-a concentration (Chl-a). From 2002 to 2004, ratios of the δ15Ncoral varied between +0.8 and +8.3‰ with inverse variation to SST (r = -0.53). Ba/Ca ratios and Chl-a concentrations were also observed to be high during seasons with low SST. These results suggested that the vertical mixing that occurs during periods of low SST carries nutrients from deeper water (δ15NDIN; +5˜+6‰) to the sea surface. In 2005 onward, δ15Ncoral and Ba/Ca ratios also had positive peaks even in high SST during periods of transient upwelling caused by frequent large typhoons (maximum wind speed 30 m/s). In addition, low δ15Ncoral (+0.8˜+2.0‰) four months after the last typhoon implied nitrogen fixation because of the lack of typhoon upwelling through the four years record of δ15Ncoral. Variations in the δ13Ccoral-carb and δ15Ncoral were synchronized, suggesting that nitrate concentration could control zooxanthellae photosynthesis. Our results suggested that δ15Ncoral holds promise as a proxy for reconstructing the transport dynamics of marine nitrate and thus also a tool for estimating nitrate origins in the tropical and subtropical oceans.

The ocean's role in polar climate change: asymmetric Arctic and Antarctic responses to greenhouse gas and ozone forcing.

PubMed

Marshall, John; Armour, Kyle C; Scott, Jeffery R; Kostov, Yavor; Hausmann, Ute; Ferreira, David; Shepherd, Theodore G; Bitz, Cecilia M

2014-07-13

In recent decades, the Arctic has been warming and sea ice disappearing. By contrast, the Southern Ocean around Antarctica has been (mainly) cooling and sea-ice extent growing. We argue here that interhemispheric asymmetries in the mean ocean circulation, with sinking in the northern North Atlantic and upwelling around Antarctica, strongly influence the sea-surface temperature (SST) response to anthropogenic greenhouse gas (GHG) forcing, accelerating warming in the Arctic while delaying it in the Antarctic. Furthermore, while the amplitude of GHG forcing has been similar at the poles, significant ozone depletion only occurs over Antarctica. We suggest that the initial response of SST around Antarctica to ozone depletion is one of cooling and only later adds to the GHG-induced warming trend as upwelling of sub-surface warm water associated with stronger surface westerlies impacts surface properties. We organize our discussion around 'climate response functions' (CRFs), i.e. the response of the climate to 'step' changes in anthropogenic forcing in which GHG and/or ozone-hole forcing is abruptly turned on and the transient response of the climate revealed and studied. Convolutions of known or postulated GHG and ozone-hole forcing functions with their respective CRFs then yield the transient forced SST response (implied by linear response theory), providing a context for discussion of the differing warming/cooling trends in the Arctic and Antarctic. We speculate that the period through which we are now passing may be one in which the delayed warming of SST associated with GHG forcing around Antarctica is largely cancelled by the cooling effects associated with the ozone hole. By mid-century, however, ozone-hole effects may instead be adding to GHG warming around Antarctica but with diminished amplitude as the ozone hole heals. The Arctic, meanwhile, responding to GHG forcing but in a manner amplified by ocean heat transport, may continue to warm at an accelerating rate.

Satellite monitoring temperature conditions spawning area of the Northeast Arctic cod in the Norwegian Sea and assessment its abundance

NASA Astrophysics Data System (ADS)

Vanyushin, George; Bulatova, Tatiana; Klochkov, Dmitriy; Troshkov, Anatoliy; Kruzhalov, Michail

2013-04-01

In this study, the attempt to consider the relationship between sea surface anomalies of temperature (SST anomalies °C) in spawning area of the Norwegian Arctic cod off the Lofoten islands in coastal zone of the Norwegian Sea and modern cod total stock biomass including forecasting assessment of future cod generation success. Continuous long-term database of the sea surface temperature (SST) was created on the NOAA satellites data. Mean monthly SST and SST anomalies are computed for the selected area on the basis of the weekly SST maps for the period of 1998-2012. These maps were plotted with the satellite SST data, as well as information of vessels, byoies and coastal stations. All data were classified by spawning seasons (March-April) and years. The results indicate that poor and low middle generations of cod (2001, 2006, 2007) occurred in years with negative or extremely high positive anomalies in the spawning area. The SST anomalies in years which were close to normal or some more normal significances provide conditions for appearance strong or very strong generations of cod (1998, 2000, 2002, 2004, 2005, 2006, 2008, 2009). Temperature conditions in concrete years influence on different indexes of cod directly. So, the mean temperature in spawning seasons in years 1999-2005 was ≈5,0°C and SST anomaly - +0,35°C, by the way average year significances indexes of cod were: total stock biomass - 1425,0 th.t., total spawning biomass - 460,0 th.t., recruitment (age 3+) - 535,0 mln. units and landings - 530,0 th.t. In spawning seasons 2006-2012 years the average data were following: mean SST ≈6,0°C, SST anomaly - +1,29°C, total stock biomass - 2185,0 th.t., total spawning biomass - 1211,0 th.t., recruitment (age 3+) - 821,0 mln. units and landings - 600,0 th.t. The SST and SST anomalies (the NOAA satellite data) characterize increase of decrease in input of warm Atlantic waters which form numerous eddies along the flows of the main warm currents thus creating favorable conditions for development of the cod larvae and fry and provide them with food stock, finally, direct influence on forming total stock biomass of cod and helping its population forecast. Key words: satellite monitoring of SST, Northeast Arctic cod, spawning area, maps of SST, prognosis.

Evaluating operational AVHRR sea surface temperature data at the coastline using surfers

NASA Astrophysics Data System (ADS)

Brewin, Robert J. W.; de Mora, Lee; Billson, Oliver; Jackson, Thomas; Russell, Paul; Brewin, Thomas G.; Shutler, Jamie D.; Miller, Peter I.; Taylor, Benjamin H.; Smyth, Tim J.; Fishwick, James R.

2017-09-01

Sea surface temperature (SST) is an essential climate variable that can be measured routinely from Earth Observation (EO) with high temporal and spatial coverage. To evaluate its suitability for an application, it is critical to know the accuracy and precision (performance) of the EO SST data. This requires comparisons with co-located and concomitant in situ data. Owing to a relatively large network of in situ platforms there is a good understanding of the performance of EO SST data in the open ocean. However, at the coastline this performance is not well known, impeded by a lack of in situ data. Here, we used in situ SST measurements collected by a group of surfers over a three year period in the coastal waters of the UK and Ireland, to improve our understanding of the performance of EO SST data at the coastline. At two beaches near the city of Plymouth, UK, the in situ SST measurements collected by the surfers were compared with in situ SST collected from two autonomous buoys located ∼7 km and ∼33 km from the coastline, and showed good agreement, with discrepancies consistent with the spatial separation of the sites. The in situ SST measurements collected by the surfers around the coastline, and those collected offshore by the two autonomous buoys, were used to evaluate the performance of operational Advanced Very High Resolution Radiometer (AVHRR) EO SST data. Results indicate: (i) a significant reduction in the performance of AVHRR at retrieving SST at the coastline, with root mean square errors in the range of 1.0 to 2.0 °C depending on the temporal difference between match-ups, significantly higher than those at the two offshore stations (0.4 to 0.6 °C); (ii) a systematic negative bias in the AVHRR retrievals of approximately 1 °C at the coastline, not observed at the two offshore stations; and (iii) an increase in the root mean square error at the coastline when the temporal difference between match-ups exceeded three hours. Harnessing new solutions to improve in situ sampling coverage at the coastline, such as tagging surfers with sensors, can improve our understanding of the performance of EO SST data in coastal regions, helping inform users interested in EO SST products for coastal applications. Yet, validating EO SST products using in situ SST data at the coastline is challenged by difficulties reconciling the two measurements, which are provided at different spatial scales in a dynamic and complex environment.

The effects of SST Gradients on Tropical Convective Systems and Implications for Tropical Cyclogenesis

NASA Astrophysics Data System (ADS)

Glazer, R.; Bourassa, M. A.; Hart, R. E.

2013-12-01

It has long been known that generally the warmer the sea surface temperature (SST), the more possible tropical cyclone (TC) genesis is, assuming the atmosphere is supportive. The conventional wisdom has been that - apart from what the TC cools through upwelling -- one value of SST represents the state of the ocean surface in the region of the storm's inner circulation. With the advent of the satellite era and fine resolution SST datasets now becoming available, we know that in reality there are gradients of SST across which developing TCs move. The influence of those gradients on tropical convection and TC genesis is largely unknown at this time. Previous studies have shown that SST gradients can significantly impact the overlying ocean surface winds leading to areas of enhanced convergence/divergence and Vorticity (Chelton et al. 2004; O'Neill et al. 2005, 2010). The magnitude of this effect approximately increases as the surface wind increases. Work by Minobe et al. (2008) concluded that a sharp SST Gradient, over the Gulf Stream for instance, could produce enough surface wind convergence to maintain a band of precipitation along the ocean front. An analysis of satellite derived SST data over the Atlantic shows that it is not uncommon for SST gradients of 2 C/200km or more to exist in the immediate environment of a Tropical System. The authors seek to understand whether the conclusions made in previous works can be applied in the case of a developing Tropical System and whether SST Gradients exist in the Tropical Atlantic to a degree that would influence the cyclogenesis process. To address this, the effects of SST gradients on tropical cyclogenesis processes are investigated using model simulations of the Weather Research and Forecasting Model (WRF). WRF is run at cloud permitting scales (2km) for real cases of co-location between a tropical system and an SST gradient exceeding 2 C/200km in the environment of the system. In subsequent runs to this control run, the SSTs are modified to give a smaller or larger SST Gradient with the same atmospheric conditions. All cases are chosen from Atlantic Hurricane Seasons between 2002-2011. The results are then analyzed in the framework of previous studies that have sought to model and understand tropical cyclogenesis using WRF (Nolan 2007; Fang and Zhang 2010).

On the spread of changes in marine low cloud cover in climate model simulations of the 21st century

NASA Astrophysics Data System (ADS)

Qu, Xin; Hall, Alex; Klein, Stephen A.; Caldwell, Peter M.

2014-05-01

In 36 climate change simulations associated with phases 3 and 5 of the Coupled Model Intercomparison Project (CMIP3 and CMIP5), changes in marine low cloud cover (LCC) exhibit a large spread, and may be either positive or negative. Here we develop a heuristic model to understand the source of the spread. The model's premise is that simulated LCC changes can be interpreted as a linear combination of contributions from factors shaping the clouds' large-scale environment. We focus primarily on two factors—the strength of the inversion capping the atmospheric boundary layer (measured by the estimated inversion strength, EIS) and sea surface temperature (SST). For a given global model, the respective contributions of EIS and SST are computed. This is done by multiplying (1) the current-climate's sensitivity of LCC to EIS or SST variations, by (2) the climate-change signal in EIS or SST. The remaining LCC changes are then attributed to changes in greenhouse gas and aerosol concentrations, and other environmental factors. The heuristic model is remarkably skillful. Its SST term dominates, accounting for nearly two-thirds of the intermodel variance of LCC changes in CMIP3 models, and about half in CMIP5 models. Of the two factors governing the SST term (the SST increase and the sensitivity of LCC to SST perturbations), the SST sensitivity drives the spread in the SST term and hence the spread in the overall LCC changes. This sensitivity varies a great deal from model to model and is strongly linked to the types of cloud and boundary layer parameterizations used in the models. EIS and SST sensitivities are also estimated using observational cloud and meteorological data. The observed sensitivities are generally consistent with the majority of models as well as expectations from prior research. Based on the observed sensitivities and the relative magnitudes of simulated EIS and SST changes (which we argue are also physically reasonable), the heuristic model predicts LCC will decrease over the 21st-century. However, to place a strong constraint, for example on the magnitude of the LCC decrease, will require longer observational records and a careful assessment of other environmental factors producing LCC changes. Meanwhile, addressing biases in simulated EIS and SST sensitivities will clearly be an important step towards reducing intermodel spread in simulated LCC changes.

Group for High Resolution Sea Surface Temperature (GHRSST) analysis fields inter-comparisons—Part 2: Near real time web-based level 4 SST Quality Monitor (L4-SQUAM)

NASA Astrophysics Data System (ADS)

Dash, Prasanjit; Ignatov, Alexander; Martin, Matthew; Donlon, Craig; Brasnett, Bruce; Reynolds, Richard W.; Banzon, Viva; Beggs, Helen; Cayula, Jean-Francois; Chao, Yi; Grumbine, Robert; Maturi, Eileen; Harris, Andy; Mittaz, Jonathan; Sapper, John; Chin, Toshio M.; Vazquez-Cuervo, Jorge; Armstrong, Edward M.; Gentemann, Chelle; Cummings, James; Piollé, Jean-François; Autret, Emmanuelle; Roberts-Jones, Jonah; Ishizaki, Shiro; Høyer, Jacob L.; Poulter, Dave

2012-11-01

There are a growing number of level 4 (L4; gap-free gridded) sea surface temperature (SST) products generated by blending SST data from various sources which are available for use in a wide variety of operational and scientific applications. In most cases, each product has been developed for a specific user community with specific requirements guiding the design of the product. Consequently differences between products are implicit. In addition, anomalous atmospheric conditions, satellite operations and production anomalies may occur which can introduce additional differences. This paper describes a new web-based system called the L4 SST Quality Monitor (L4-SQUAM) developed to monitor the quality of L4 SST products. L4-SQUAM intercompares thirteen L4 products with 1-day latency in an operational environment serving the needs of both L4 SST product users and producers. Relative differences between products are computed and visualized using maps, histograms, time series plots and Hovmöller diagrams, for all combinations of products. In addition, products are compared to quality controlled in situ SST data (available from the in situ SST Quality Monitor, iQUAM, companion system) in a consistent manner. A full history of products statistics is retained in L4-SQUAM for time series analysis. L4-SQUAM complements the two other Group for High Resolution SST (GHRSST) tools, the GHRSST Multi Product Ensemble (GMPE) and the High Resolution Diagnostic Data Set (HRDDS) systems, documented in part 1 of this paper and elsewhere, respectively. Our results reveal significant differences between SST products in coastal and open ocean areas. Differences of >2 °C are often observed at high latitudes partly due to different treatment of the sea-ice transition zone. Thus when an ice flag is available, the intercomparisons are performed in two ways: including and excluding ice-flagged grid points. Such differences are significant and call for a community effort to understand their root cause and ensure consistency between SST products. Future work focuses on including the remaining daily L4 SST products, accommodating for newer L4 SSTs which resolve the diurnal variability and evaluating retrospectively regenerated L4 SSTs to support satellite data reprocessing efforts aimed at generating improved SST Climate Data Records.

Rasch analysis indicates that the Simple Shoulder Test is robust, but minor item modifications and attention to gender differences should be considered.

PubMed

Raman, Jayaprakash; MacDermid, Joy C; Walton, David; Athwal, George S

Repeated cross-sectional study. Multiple studies have evaluated the psychometric properties of the Simple Shoulder Test (SST) through traditional methods supporting it as valid and reliable. Since the evidentiary pool supporting the use of the SST has only partially addressed key measurement properties and the development of SST pre-dates the common use of Rasch model, validation of SST has become a necessity to establish as a reliable and valid PRO for shoulder conditions. To date, no study has analysed SST through Rasch, a modern method for analyzing properties of measurement tools. The purpose of this study was to perform a Rasch analysis of the SST to assess the overall fit to the Rasch model, individual item fit, gender-based DIF, local dependency of items and the unidimensionality of the scale. A secondary purpose was to determine the stability of fit to the Rasch model when captured pre-operatively or post-operatively. Patients completed SST before surgery and between 6 months and 1 year after surgery. Rasch analysis was performed to analyse the carious properties of SST through the Rasch model. SST appears to be robust when tested against the Rasch model. Rasch analysis has highlighted potential areas for to improve in the SST questionnaire. The potential areas to improve are to consider questions that measure the ability of a person to lift the arm above shoulder level and to consider gender differences when measuring the ability to carry weights with the affected arm. This study adds to previous body of empirical evidence arising classical measurement approaches that have suggested that the SST has robust measurement properties, by providing evidence of adequate fit to the Rasch model after minor adjustments. The results of this study should provide confidence to clinicians on SST who wish to use a brief shoulder-specific measure in their practice. The SST appears to be robust when tested against the Rasch model despite some potential areas for improvement. The potential areas that should be explored in future Rasch analyses are the questions that measure the ability of a person to lift the arm above shoulder level and the potential for gender differences when measuring the ability to carry weights with the affected arm. Copyright © 2017 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

An evaluation of the effect of recent temperature variability on the prediction of coral bleaching events.

PubMed

Donner, Simon D

2011-07-01

Over the past 30 years, warm thermal disturbances have become commonplace on coral reefs worldwide. These periods of anomalous sea surface temperature (SST) can lead to coral bleaching, a breakdown of the symbiosis between the host coral and symbiotic dinoflagellates which reside in coral tissue. The onset of bleaching is typically predicted to occur when the SST exceeds a local climatological maximum by 1 degrees C for a month or more. However, recent evidence suggests that the threshold at which bleaching occurs may depend on thermal history. This study uses global SST data sets (HadISST and NOAA AVHRR) and mass coral bleaching reports (from Reefbase) to examine the effect of historical SST variability on the accuracy of bleaching prediction. Two variability-based bleaching prediction methods are developed from global analysis of seasonal and interannual SST variability. The first method employs a local bleaching threshold derived from the historical variability in maximum annual SST to account for spatial variability in past thermal disturbance frequency. The second method uses a different formula to estimate the local climatological maximum to account for the low seasonality of SST in the tropics. The new prediction methods are tested against the common globally fixed threshold method using the observed bleaching reports. The results find that estimating the bleaching threshold from local historical SST variability delivers the highest predictive power, but also a higher rate of Type I errors. The second method has the lowest predictive power globally, though regional analysis suggests that it may be applicable in equatorial regions. The historical data analysis suggests that the bleaching threshold may have appeared to be constant globally because the magnitude of interannual variability in maximum SST is similar for many of the world's coral reef ecosystems. For example, the results show that a SST anomaly of 1 degrees C is equivalent to 1.73-2.94 standard deviations of the maximum monthly SST for two-thirds of the world's coral reefs. Coral reefs in the few regions that experience anomalously high interannual SST variability like the equatorial Pacific could prove critical to understanding how coral communities acclimate or adapt to frequent and/or severe thermal disturbances.

Influences of Local Sea-Surface Temperatures and Large-scale Dynamics on Monthly Precipitation Inferred from Two 10-year GCM-Simulations

NASA Technical Reports Server (NTRS)

Sud, Y. C.; Walker, G. K.; Zhou, Y.; Lau, W. K.-M.

2007-01-01

Two parallel sets of 10-year long: January 1, 1982 to December 31, 1991, simulations were made with the finite volume General Circulation Model (fvGCM) in which the model integrations were forced with prescribed sea-surface temperature fields (SSTs) available as two separate SST-datasets. One dataset contained naturally varying monthly SSTs for the chosen period, and the oth& had the 12-monthly mean SSTs for the same period. Plots of evaporation, precipitation, and atmosphere-column moisture convergence, binned by l C SST intervals show that except for the tropics, the precipitation is more strongly constrained by large-scale dynamics as opposed to local SST. Binning data by SST naturally provided an ensemble average of data contributed from disparate locations with same SST; such averages could be expected to mitigate all location related influences. However, the plots revealed: i) evaporation, vertical velocity, and precipitation are very robust and remarkably similar for each of the two simulations and even for the data from 1987-ENSO-year simulation; ii) while the evaporation increased monotonically with SST up to about 27 C, the precipitation did not; iii) precipitation correlated much better with the column vertical velocity as opposed to SST suggesting that the influence of dynamical circulation including non-local SSTs is stronger than local-SSTs. The precipitation fields were doubly binned with respect to SST and boundary-layer mass and/or moisture convergence. The analysis discerned the rate of change of precipitation with local SST as a sum of partial derivative of precipitation with local SST plus partial derivative of precipitation with boundary layer moisture convergence multiplied by the rate of change of boundary-layer moisture convergence with SST (see Eqn. 3 of Section 4.5). This analysis is mathematically rigorous as well as provides a quantitative measure of the influence of local SST on the local precipitation. The results were recast to examine the dependence of local rainfall on local SSTs; it was discernible only in the tropics. Our methodology can be used for computing relationship between any forcing function and its effect(s) on a chosen field.

A dual but asymmetric role of the dorsal anterior cingulate cortex in response inhibition and switching from a non-salient to salient action

PubMed Central

Manza, Peter; Hu, Sien; Chao, Herta H.; Zhang, Sheng; Leung, Hoi-Chung; Li, Chiang-shan R.

2016-01-01

Response inhibition and salience detection are among the most studied psychological constructs of cognitive control. Despite a growing body of work, how inhibition and salience processing interact and engage regional brain activations remains unclear. Here, we examined this issue in a stop signal task (SST), where a prepotent response needs to be inhibited to allow an alternative, less dominant response. Sixteen adult individuals performed two versions of the SST each with 25% (SST25) and 75% (SST75) of stop trials. We posited that greater regional activations to the infrequent trial type in each condition (i.e., to stop as compared to go trials in SST25 and to go as compared to stop trials in SST75) support salience detection. Further, successful inhibition in stop trials requires attention to the stop signal to trigger motor inhibition, and the stop signal reaction time (SSRT) has been used to index the efficiency of motor response inhibition. Therefore, greater regional activations to stop as compared to go success trials in association with the stop signal reaction time (SSRT) serves to expedite response inhibition. In support of an interactive role, the dorsal anterior cingulate cortex (dACC) increases activation to salience detection in both SST25 and SST75, but only mediates response inhibition in SST75. Thus, infrequency response in the dACC supports motor inhibition only when stopping has become a routine. In contrast, although the evidence is less robust, the pre-supplementary motor area (pre-SMA) increases activity to the infrequent stimulus and supports inhibition in both SST25 and SST75. These findings clarify a unique role of the dACC and add to the literature that distinguishes dACC and pre-SMA functions in cognitive control. PMID:27126003

A dual but asymmetric role of the dorsal anterior cingulate cortex in response inhibition and switching from a non-salient to salient action.

PubMed

Manza, Peter; Hu, Sien; Chao, Herta H; Zhang, Sheng; Leung, Hoi-Chung; Li, Chiang-Shan R

2016-07-01

Response inhibition and salience detection are among the most studied psychological constructs of cognitive control. Despite a growing body of work, how inhibition and salience processing interact and engage regional brain activations remains unclear. Here, we examined this issue in a stop signal task (SST), where a prepotent response needs to be inhibited to allow an alternative, less dominant response. Sixteen adult individuals performed two versions of the SST each with 25% (SST25) and 75% (SST75) of stop trials. We posited that greater regional activations to the infrequent trial type in each condition (i.e., to stop as compared to go trials in SST25 and to go as compared to stop trials in SST75) support salience detection. Further, successful inhibition in stop trials requires attention to the stop signal to trigger motor inhibition, and the stop signal reaction time (SSRT) has been used to index the efficiency of motor response inhibition. Therefore, greater regional activations to stop as compared to go success trials in association with the stop signal reaction time (SSRT) serve to expedite response inhibition. In support of an interactive role, the dorsal anterior cingulate cortex (dACC) increases activation to salience detection in both SST25 and SST75, but only mediates response inhibition in SST75. Thus, infrequency response in the dACC supports motor inhibition only when stopping has become a routine. In contrast, although the evidence is less robust, the pre-supplementary motor area (pre-SMA) increases activity to the infrequent stimulus and supports inhibition in both SST25 and SST75. These findings clarify a unique role of the dACC and add to the literature that distinguishes dACC and pre-SMA functions in cognitive control. Copyright © 2016 Elsevier Inc. All rights reserved.

Understanding Southern Ocean SST Trends in Historical Simulations and Observations

NASA Astrophysics Data System (ADS)

Kostov, Yavor; Ferreira, David; Marshall, John; Armour, Kyle

2017-04-01

Historical simulations with CMIP5 global climate models do not reproduce the observed 1979-2014 Southern Ocean (SO) cooling, and most ensemble members predict gradual warming around Antarctica. In order to understand this discrepancy and the mechanisms behind the SO cooling, we analyze output from 19 CMIP5 models. For each ensemble member we estimate the characteristic responses of SO SST to step changes in greenhouse gas (GHG) forcing and in the seasonal indices of the Southern Annular Mode (SAM). Using these step-response functions and linear convolution theory, we reconstruct the original CMIP5 simulations of 1979-2014 SO SST trends. We recover the CMIP5 ensemble mean trend, capture the intermodel spread, and reproduce very well the behavior of individual models. We thus suggest that GHG forcing and the SAM are major drivers of the simulated 1979-2014 SO SST trends. In consistence with the seasonal signature of the Antarctic ozone hole, our results imply that the summer (DJF) and fall (MAM) SAM exert a particularly important effect on the SO SST. In some CMIP5 models the SO SST response to SAM partially counteracts the warming due to GHG forcing, while in other ensemble members the SAM-induced SO SST trends complement the warming effect of GHG forcing. The compensation between GHG and SAM-induced SO SST anomalies is model-dependent and is determined by multiple factors. Firstly, CMIP5 models have different characteristic SST step response functions to SAM. Kostov et al. (2016) relate these differences to biases in the models' climatological SO temperature gradients. Secondly, many CMIP5 historical simulations underestimate the observed positive trends in the DJF and MAM seasonal SAM indices. We show that this affects the models' ability to reproduce the observed SO cooling. Last but not least, CMIP5 models differ in their SO SST step response functions to GHG forcing. Understanding the diverse behavior of CMIP5 models helps shed light on the physical processes that drive SST trends in the real SO.

sST2 translation is regulated by FGF2 via an hnRNP A1-mediated IRES-dependent mechanism.

PubMed

Kunze, Michael M; Benz, Fabienne; Brauß, Thilo F; Lampe, Sebastian; Weigand, Julia E; Braun, Johannes; Richter, Florian M; Wittig, Ilka; Brüne, Bernhard; Schmid, Tobias

2016-07-01

Translation is an energy-intensive process and tightly regulated. Generally, translation is initiated in a cap-dependent manner. Under stress conditions, typically found within the tumor microenvironment in association with e.g. nutrient deprivation or hypoxia, cap-dependent translation decreases, and alternative modes of translation initiation become more important. Specifically, internal ribosome entry sites (IRES) facilitate translation of specific mRNAs under otherwise translation-inhibitory conditions. This mechanism is controlled by IRES trans-acting factors (ITAF), i.e. by RNA-binding proteins, which interact with and determine the activity of selected IRESs. We aimed at characterizing the translational regulation of the IL-33 decoy receptor sST2, which was enhanced by fibroblast growth factor 2 (FGF2). We identified and verified an IRES within the 5'UTR of sST2. Furthermore, we found that MEK/ERK signaling contributes to FGF2-induced, sST2-IRES activation and translation. Determination of the sST2-5'UTR structure by in-line probing followed by deletion analyses identified 23 nucleotides within the sST2-5'UTR to be required for optimal IRES activity. Finally, we show that the RNA-binding protein heterogeneous ribonucleoprotein A1 (hnRNP A1) binds to the sST2-5'UTR, acts as an ITAF, and thus controls the activity of the sST2-IRES and consequently sST2 translation. Specifically, FGF2 enhances nuclear-cytoplasmic translocation of hnRNP A1, which requires intact MEK/ERK activity. In summary, we provide evidence that the sST2-5'UTR contains an IRES element, which is activated by a MEK/ERK-dependent increase in cytoplasmic localization of hnRNP A1 in response to FGF2, enhancing the translation of sST2. Copyright © 2016 Elsevier B.V. All rights reserved.

Pathfinder Sea Surface Temperature Climate Data Record

NASA Astrophysics Data System (ADS)

Baker-Yeboah, S.; Saha, K.; Zhang, D.; Casey, K. S.

2016-02-01

Global sea surface temperature (SST) fields are important in understanding ocean and climate variability. The NOAA National Centers for Environmental Information (NCEI) develops and maintains a high resolution, long-term, climate data record (CDR) of global satellite SST. These SST values are generated at approximately 4 km resolution using Advanced Very High Resolution Radiometer (AVHRR) instruments aboard NOAA polar-orbiting satellites going back to 1981. The Pathfinder SST algorithm is based on the Non-Linear SST algorithm using the modernized NASA SeaWiFS Data Analysis System (SeaDAS). Coefficients for this SST product were generated using regression analyses with co-located in situ and satellite measurements. Previous versions of Pathfinder included level 3 collated (L3C) products. Pathfinder Version 5.3 includes level 2 pre-processed (L2P), level 3 Uncollated (L3C), and L3C products. Notably, the data were processed in the cloud using Amazon Web Services and are made available through all of the modern web visualization and subset services provided by the THREDDS Data Server, the Live Access Server, and the OPeNDAP Hyrax Server.In this version of Pathfinder SST, anomalous hot-spots at land-water boundaries are better identified and the dataset includes updated land masks and sea ice data over the Antarctic ice shelves. All quality levels of SST values are generated, giving the user greater flexibility and the option to apply their own cloud-masking procedures. Additional improvements include consistent cloud tree tests for NOAA-07 and NOAA-19 with respect to the other sensors, improved SSTs in sun glint areas, and netCDF file format improvements to ensure consistency with the latest Group for High Resolution SST (GHRSST) requirements. This quality controlled satellite SST field is a reference environmental data record utilized as a primary resource of SST for numerous regional and global marine efforts.

Low frequency North Atlantic SST variability: Weather noise forcing and coupled response

NASA Astrophysics Data System (ADS)

Fan, Meizhu

A method to diagnose the causes of low frequency SST variability is developed, tested and applied in an ideal case and real climate. In the ideal case, a free simulation of the COLA CGCM is taken as synthetic observations. For real climate, we take NCEP reanalysis atmospheric data and Reynolds SST as observations. Both the synthetic and actual observation data show that weather noise is the main component of atmospheric variability at subtropics and high-latitude. Diagnoses of results from the ideal case suggest that most of the synthetic observed SST variability can be reproduced by the weather noise surface fluxes forcing. This includes the "observed" low frequency SST patterns in the North Atlantic and their corresponding time evolution. Among all the noise surface fluxes, heat flux plays a major role. The results from simulations using actual observations also suggest that the observed SST variability is mostly atmospheric weather noise forced. The regional atmospheric noise forcing, especially the heat flux noise forcing, is the major source of the low frequency SST variability in the North Atlantic. The observed SST tripole mode has about a 12 year period and it can be reasonably reproduced by the weather noise forcing in terms of its period, spatial pattern and variance. Based on our diagnosis, it is argued that the SST tripole is mainly forced by local atmospheric heat flux noise. The gyre circulation plays a secondary role: the anomalous gyre circulation advects mean thermal features across the inter-gyre boundary, and the mean gyre advection carries SST anomalies along the inter-gyre boundary. The diagnosis is compared with a delayed oscillator theory. We find that the delayed oscillator theory is not supported and that the SST tripole mode is forced by weather noise heat flux noise. However, the result may be model dependent.

The plasma levels of soluble ST2 as a marker of gut mucosal damage in early HIV infection

PubMed Central

Mehraj, Vikram; Jenabian, Mohammad-Ali; Ponte, Rosalie; Lebouché, Bertrand; Costiniuk, Cecilia; Thomas, Réjean; Baril, Jean-Guy; LeBlanc, Roger; Cox, Joseph; Tremblay, Cécile; Routy, Jean-Pierre

2016-01-01

Objective: Following tissue barrier breaches, interleukin-33 (IL-33) is released as an ‘alarmin’ to induce inflammation. Soluble suppression of tumorigenicity 2 (sST2), as an IL-33 decoy receptor, contributes to limit inflammation. We assessed the relationship between the IL-33/ST2 axis and markers of gut mucosal damage in patients with early (EHI) and chronic HIV infection (CHI) and elite controllers. Design: Analyses on patients with EHI and CHI were conducted to determine IL-33/sST2 changes over time. Methods: IL-33 and sST2 levels were measured in plasma. Correlations between sST2 levels and plasma viral load, CD4+ and CD8+ T-cell counts, expression of T-cell activation/exhaustion markers, gut mucosal damage, microbial translocation and inflammation markers, as well as kynurenine/tryptophan ratio were assessed. Results: Plasma sST2 levels were elevated in EHI compared with untreated CHI and uninfected controls, whereas IL-33 levels were comparable in all groups. In EHI, sST2 levels were positively correlated with the CD8+ T-cell count and the percentage of T cells expressing activation and exhaustion markers, but not with viral load or CD4+ T-cell count. Plasma sST2 levels also correlated with plasma levels of gut mucosal damage, microbial translocation and kynurenine/tryptophan ratio and for some markers of inflammation. Prospective analyses showed that early antiretroviral therapy had no impact on sST2 levels, whereas longer treatment duration initiated during CHI normalized sST2. Conclusion: As sST2 levels were elevated in EHI and were correlated with CD8+ T-cell count, immune activation, and microbial translocation, sST2 may serve as a marker of disease progression, gut damage and may directly contribute to HIV pathogenesis. PMID:27045377

Impact of High Resolution SST Data on Regional Weather Forecasts

NASA Technical Reports Server (NTRS)

Jedlovec, Gary J.; Case, Jonathon; LaFontaine, Frank; Vazquez, Jorge; Mattocks, Craig

2010-01-01

Past studies have shown that the use of coarse resolution SST products such as from the real-time global (RTG) SST analysis[1] or other coarse resolution once-a-day products do not properly portray the diurnal variability of fluxes of heat and moisture from the ocean that drive the formation of low level clouds and precipitation over the ocean. For example, the use of high resolution MODIS SST composite [2] to initialize the Advanced Research Weather Research and Forecast (WRF) (ARW) [3] has been shown to improve the prediction of sensible weather parameters in coastal regions [4][5}. In an extend study, [6] compared the MODIS SST composite product to the RTG SST analysis and evaluated forecast differences for a 6 month period from March through August 2007 over the Florida coastal regions. In a comparison to buoy data, they found that that the MODIS SST composites reduced the bias and standard deviation over that of the RTG data. These improvements led to significant changes in the initial and forecasted heat fluxes and the resulting surface temperature fields, wind patterns, and cloud distributions. They also showed that the MODIS composite SST product, produced for the Terra and Aqua satellite overpass times, captured a component of the diurnal cycle in SSTs not represented in the RTG or other one-a-day SST analyses. Failure to properly incorporate these effects in the WRF initialization cycle led to temperature biases in the resulting short term forecasts. The forecast impact was limited in some situations however, due to composite product inaccuracies brought about by data latency during periods of long-term cloud cover. This paper focuses on the forecast impact of an enhanced MODIS/AMSR-E composite SST product designed to reduce inaccuracies due data latency in the MODIS only composite product.

Not So Giants: Mice Lacking Both Somatostatin and Cortistatin Have High GH Levels but Show No Changes in Growth Rate or IGF-1 Levels.

PubMed

Pedraza-Arévalo, S; Córdoba-Chacón, J; Pozo-Salas, A I; L-López, F; de Lecea, L; Gahete, M D; Castaño, J P; Luque, R M

2015-06-01

Somatostatin (SST) and cortistatin (CORT) are two highly related neuropeptides involved in the regulation of various endocrine secretions. In particular, SST and CORT are two primary negative regulators of GH secretion. Consequently, single SST or CORT knockout mice exhibit elevated GH levels; however, this does not lead to increased IGF-1 levels or somatic growth. This apparent lack of correspondence has been suggested to result from compensatory mechanisms between both peptides. To test this hypothesis, in this study we explored, for the first time, the consequences of simultaneously deleting endogenous SST and CORT by generating a double SST/CORT knockout mouse model and exploring its endocrine and metabolic phenotype. Our results demonstrate that simultaneous deletion of SST and CORT induced a drastic elevation of endogenous GH levels, which, surprisingly, did not lead to changes in growth rate or IGF-1 levels, suggesting the existence of additional factors/systems that, in the absence of endogenous SST and CORT, could counteract GH actions. Notably, elevation in circulating GH levels were not accompanied by changes in pituitary GH expression or by alterations in the expression of its main regulators (GHRH and ghrelin) or their receptors (GHRH receptor, GHS receptor, or SST/CORT receptors) at the hypothalamic or pituitary level. However, although double-SST/CORT knockout male mice exhibited normal glucose and insulin levels, they had improved insulin sensitivity compared with the control mice. Therefore, these results suggest the existence of an intricate interplay among the known (SST/CORT), and likely unknown, inhibitory components of the GH/IGF-1 axis to regulate somatic growth and glucose/insulin homeostasis.

The Use of Neural Networks in Identifying Error Sources in Satellite-Derived Tropical SST Estimates

PubMed Central

Lee, Yung-Hsiang; Ho, Chung-Ru; Su, Feng-Chun; Kuo, Nan-Jung; Cheng, Yu-Hsin

2011-01-01

An neural network model of data mining is used to identify error sources in satellite-derived tropical sea surface temperature (SST) estimates from thermal infrared sensors onboard the Geostationary Operational Environmental Satellite (GOES). By using the Back Propagation Network (BPN) algorithm, it is found that air temperature, relative humidity, and wind speed variation are the major factors causing the errors of GOES SST products in the tropical Pacific. The accuracy of SST estimates is also improved by the model. The root mean square error (RMSE) for the daily SST estimate is reduced from 0.58 K to 0.38 K and mean absolute percentage error (MAPE) is 1.03%. For the hourly mean SST estimate, its RMSE is also reduced from 0.66 K to 0.44 K and the MAPE is 1.3%. PMID:22164030

Analysis of the VIIRS cloud mask, comparison with the NAVOCEANO cloud mask, and how they complement each other

NASA Astrophysics Data System (ADS)

Cayula, Jean-François P.; May, Douglas A.; McKenzie, Bruce D.

2014-05-01

The Visible Infrared Imaging Radiometer Suite (VIIRS) Cloud Mask (VCM) Intermediate Product (IP) has been developed for use with Suomi National Polar-orbiting Partnership (NPP) VIIRS Environmental Data Record (EDR) products. In particular, the VIIRS Sea Surface Temperature (SST) EDR relies on VCM to identify cloud contaminated observations. Unfortunately, VCM does not appear to perform as well as cloud detection algorithms for SST. This may be due to similar but different goals of the two algorithms. VCM is concerned with detecting clouds while SST is interested in identifying clear observations. The result is that in undetermined cases VCM defaults to "clear," while the SST cloud detection defaults to "cloud." This problem is further compounded because classic SST cloud detection often flags as "cloud" all types of corrupted data, thus making a comparison with VCM difficult. The Naval Oceanographic Office (NAVOCEANO), which operationally produces a VIIRS SST product, relies on cloud detection from the NAVOCEANO Cloud Mask (NCM), adapted from cloud detection schemes designed for SST processing. To analyze VCM, the NAVOCEANO SST process was modified to attach the VCM flags to all SST retrievals. Global statistics are computed for both day and night data. The cases where NCM and/or VCM tag data as cloud-contaminated or clear can then be investigated. By analyzing the VCM individual test flags in conjunction with the status of NCM, areas where VCM can complement NCM are identified.

Adaptive synchrosqueezing based on a quilted short-time Fourier transform

NASA Astrophysics Data System (ADS)

Berrian, Alexander; Saito, Naoki

2017-08-01

In recent years, the synchrosqueezing transform (SST) has gained popularity as a method for the analysis of signals that can be broken down into multiple components determined by instantaneous amplitudes and phases. One such version of SST, based on the short-time Fourier transform (STFT), enables the sharpening of instantaneous frequency (IF) information derived from the STFT, as well as the separation of amplitude-phase components corresponding to distinct IF curves. However, this SST is limited by the time-frequency resolution of the underlying window function, and may not resolve signals exhibiting diverse time-frequency behaviors with sufficient accuracy. In this work, we develop a framework for an SST based on a "quilted" short-time Fourier transform (SST-QSTFT), which allows adaptation to signal behavior in separate time-frequency regions through the use of multiple windows. This motivates us to introduce a discrete reassignment frequency formula based on a finite difference of the phase spectrum, ensuring computational accuracy for a wider variety of windows. We develop a theoretical framework for the SST-QSTFT in both the continuous and the discrete settings, and describe an algorithm for the automatic selection of optimal windows depending on the region of interest. Using synthetic data, we demonstrate the superior numerical performance of SST-QSTFT relative to other SST methods in a noisy context. Finally, we apply SST-QSTFT to audio recordings of animal calls to demonstrate the potential of our method for the analysis of real bioacoustic signals.

Psychometric Properties of the Persian Version of the Simple Shoulder Test (SST) Questionnaire.

PubMed

Ebrahimzadeh, Mohammad H; Vahedi, Ehsan; Baradaran, Aslan; Birjandinejad, Ali; Seyyed-Hoseinian, Seyyed-Hadi; Bagheri, Farshid; Kachooei, Amir Reza

2016-10-01

To validate the Persian version of the simple shoulder test in patients with shoulder joint problems. Following Beaton`s guideline, translation and back translation was conducted. We reached to a consensus on the Persian version of SST. To test the face validity in a pilot study, the Persian SST was administered to 20 individuals with shoulder joint conditions. We enrolled 148 consecutive patients with shoulder problem to fill the Persian SST, shoulder specific measure including Oxford shoulder score (OSS) and two general measures including DASH and SF-36. To measure the test-retest reliability, 42 patients were randomly asked to fill the Persian-SST for the second time after one week. Cronbach's alpha coefficient was used to demonstrate internal consistency over the 12 items of Persian-SST. ICC for the total questionnaire was 0.61 showing good and acceptable test-retest reliability. ICC for individual items ranged from 0.32 to 0.79. The total Cronbach's alpha was 0.84 showing good internal consistency over the 12 items of the Persian-SST. Validity testing showed strong correlation between SST and OSS and DASH. The correlation with OSS was positive while with DASH scores was negative. The correlation was also good to strong with all physical and most mental subscales of the SF-36. Correlation coefficient was higher with DASH and OSS in compare to SF-36. Persian version of SST found to be valid and reliable instrument for shoulder joint pain and function assessment in Iranian population.

Sense or Sensibility?: How Commitment Mediates the Role of Self-Service Technology on Loyalty

NASA Astrophysics Data System (ADS)

Singh, Sangeeta; Olsen, Line Lervik

It has been well documented that employing self-service technology (SST) results in considerable cost savings but few studies have examined its impact on consumers’ behavior. We apply a well-recognized model from the field of services marketing in an SST context. We examine how the established relationships between satisfaction, affective and calculative commitments, and loyalty are affected when the service is provided through a technology interface as opposed to service personnel. We then present two alternative perspectives on the role of SST. The first is based on the predominant assumption that SST is a moderator of the relationship between customer loyalty and its drivers, while the other rests on the assumption that SST is just another context and that its role in affecting customer loyalty is mediated by drivers of loyalty. A cross-sectional study conducted in the banking industry shows that SST does not change everything. The classical model of how customers evaluate services and the predictors of loyalty are replicated in the SST setting. Interestingly, SST does not have a direct influence on loyalty by itself but its effects are mediated by commitment. However, it is the affective commitment that is more important in forming loyalty toward the service provider.

Multiscale mechanical integrity of human supraspinatus tendon in shear after elastin depletion.

PubMed

Fang, Fei; Lake, Spencer P

2016-10-01

Human supraspinatus tendon (SST) exhibits region-specific nonlinear mechanical properties under tension, which have been attributed to its complex multiaxial physiological loading environment. However, the mechanical response and underlying multiscale mechanism regulating SST behavior under other loading scenarios are poorly understood. Furthermore, little is known about the contribution of elastin to tendon mechanics. We hypothesized that (1) SST exhibits region-specific shear mechanical properties, (2) fiber sliding is the predominant mode of local matrix deformation in SST in shear, and (3) elastin helps maintain SST mechanical integrity by facilitating force transfer among collagen fibers. Through the use of biomechanical testing and multiphoton microscopy, we measured the multiscale mechanical behavior of human SST in shear before and after elastase treatment. Three distinct SST regions showed similar stresses and microscale deformation. Collagen fiber reorganization and sliding were physical mechanisms observed as the SST response to shear loading. Measures of microscale deformation were highly variable, likely due to a high degree of extracellular matrix heterogeneity. After elastase treatment, tendon exhibited significantly decreased stresses under shear loading, particularly at low strains. These results show that elastin contributes to tendon mechanics in shear, further complementing our understanding of multiscale tendon structure-function relationships. Copyright © 2016 Elsevier Ltd. All rights reserved.

Improved potential fishing zone forecast along East coast of India.

NASA Astrophysics Data System (ADS)

Srinivasa Rao, N.; Rao, M. V.; Chowdhary, S. B.; Rao, K. H.; Ramana, I. V.

Marine fisheries provide support to millions of fishermen community in terms of their living and livelihood Remote sensing technology proved to be useful for successful fishing in reducing time fuel and manpower because of its synoptic coverage Potential Fishing Zone PFZ forecast is being provided to the fishing industry in near-real time since 1992 using SST data derived from NOAA AVHRR thermal IR channel Retrieval of chlorophyll and its mapping has been done over Bay of Bengal from IRS-P4 OCM data Synergetic study of SST and chlorophyll has been established and implemented recently for an improved PFZ forecast The validation of these forecasts revealed 2-3 fold increases in fish catch along east coast of India This program provides socio-economic benefits to the fishermen living all along the Indian coast

Technology sensitivity studies for a Mach 3.0 civil transport

NASA Technical Reports Server (NTRS)

Coen, Peter G.

1988-01-01

The level of technological sophistication required for the economic viability and environmental acceptability of a Mach 3.0-cruise SST is evaluated, with a view to the development schedule and initial operating date into which the maturity of various essential technologies will translate. Attention is given to the effect of advanced aerodynamic, propulsion, structural and subsystem technologies on takeoff gross weight. A dramatic impact is noted to result from the combination of prospective technological advances in flow laminarization, advanced structures and materials, etc.

Testing for Soluble ST2 in Heart Failure Patients: Reliability of a Point of Care Method.

PubMed

Gruson, Damien; Ferracin, Benjamin; Ahn, Sylvie A; Rousseau, Michel F

2017-01-01

Our objective was to determine soluble ST2 (sST2) concentrations in heart failure (HF) patients with a point-of-care (POCT) assay. sST2 levels were measured in 71 HF patients with both POCT and ELISA methods. The concentrations of sST2 were correlated to HF severity and to some established biomarkers of cardiovascular risk. sST2 levels measured with the ASPECT-PLUS POCT method were significantly correlated with the comparison ELISA assay (r = 0.94, p < 0.01) and were related to HF severity. Levels of sST2 measured with the POCT assay were significantly correlated to NT-proBNP (r = 0.57, p < 0.001), BNP (r = 0.75, p < 0.001), Galectin-3 (r = 0.40, p < 0.01) and PTH (1-84) (r = 0.39, p < 0.01). POCT and ELISA methods for sST2 testing were significantly correlated, and our results confirmed also the clinical reliability of the sST2 POCT assay. Furthermore, the POCT method allows a faster delivery of results to physicians.

Mechanistic prediction of fission-gas behavior during in-cell transient heating tests on LWR fuel using the GRASS-SST and FASTGRASS computer codes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rest, J; Gehl, S M

1979-01-01

GRASS-SST and FASTGRASS are mechanistic computer codes for predicting fission-gas behavior in UO/sub 2/-base fuels during steady-state and transient conditions. FASTGRASS was developed in order to satisfy the need for a fast-running alternative to GRASS-SST. Althrough based on GRASS-SST, FASTGRASS is approximately an order of magnitude quicker in execution. The GRASS-SST transient analysis has evolved through comparisons of code predictions with the fission-gas release and physical phenomena that occur during reactor operation and transient direct-electrical-heating (DEH) testing of irradiated light-water reactor fuel. The FASTGRASS calculational procedure is described in this paper, along with models of key physical processes included inmore » both FASTGRASS and GRASS-SST. Predictions of fission-gas release obtained from GRASS-SST and FASTGRASS analyses are compared with experimental observations from a series of DEH tests. The major conclusions is that the computer codes should include an improved model for the evolution of the grain-edge porosity.« less

The influence of tide on sea surface temperature in the marginal sea of northwest Pacific Ocean

NASA Astrophysics Data System (ADS)

Huang, Shih-Jen; Tsai, Yun-Chan; Ho, Chung-Ru; Lo, Yao-Tsai; Kuo, Nan-Jung

2017-10-01

Tide gauge data provided by the University of Hawaii Sea Level Center and daily sea surface temperature (SST) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) product are used in this study to analyze the influence of tide on the SST in the seas of Northwestern Pacific. In the marginal region, the climatology SST is lower in the northwestern area than that in the southeastern area. In the coastal region, the SST at spring tide is higher than that at neap tide in winter, but it is lower in other seasons. In the adjacent waters of East China Sea and Yellow Sea, the SST at spring tide is higher than that at neap tide in winter and summer but it is lower in spring and autumn. In the open ocean region, the SST at spring tide is higher than that at neap tide in winter, but it is lower in other seasons. In conclusion, not only the river discharge and topography, but also tides could influence the SST variations, especially in the open ocean region.

North Pacific Origins of Northern Hemisphere Glaciations: The View from the Kuroshio Extension

NASA Astrophysics Data System (ADS)

Venti, N. L.; Billups, K.; Herbert, T.

2013-12-01

In modern climate, westerly winds augmented by the East Asian winter monsoon (EAWM) cause prodigious ocean-atmosphere heat flux (>100 Wm-2) and provide the primary source of iron to the micronutrient-limited North Pacific. Here we present a suite of high-resolution (2500-year time step) Plio-Pleistocene (3.00-1.76 Ma) proxy records generated in the Kuroshio Current Extension (KCE; Ocean Drilling Program Site 1208). These suggest regularly increased interaction of the EAWM with the North Pacific Ocean prior to obliquity-paced Northern Hemisphere glaciations (NHG). We propose that in the Pleistocene, obliquity-paced EAWM intensification caused NHG by 1) advecting heat and moisture to the atmosphere for snow fall over North America and 2) delivering iron via dust to fertilize the basin, thereby increasing primary productivity and reducing atmospheric CO2 concentrations. To further test this hypothesis, we are exploring appropriate dust proxies and high-resolution CO2 reconstruction. To examine heat transfer, we reconstruct seasonal sea surface temperature (SST) by comparing summer hydrography (salinity and temperature) to a mean annual SST estimate. Planktic foraminifer (warm-water dwelling Globigerinoides ruber) Δδ18O values reflect summer hydrography--KCE warmth. An alkenone-based annual mean SST estimate, on the other hand, incorporates winter cooling from EAWM-enhanced westerlies. With NHG onset at 2.73 Ma, summer SST increases while mean annual SST decreases, suggesting increased heat loss from the subtropical ocean to the mid-latitude atmosphere. On the orbital scale, summer hydrography varies with summer/fall overhead insolation at the 19-kyr precessional band, but not obliquity, a common low-latitude pattern. In contrast, mean annual SST varies primarily at the 41-kyr obliquity period, SST cycles leading high-latitude climate (benthic foraminifer δ18O values). This consistent relationship implies that increased ocean-atmosphere heat transfer in the NW Pacific contributed to rather than resulted from the glaciations. Alkenone mass accumulation rate (MAR), sediment lithology, and magnetic susceptibility support CO2 changes. Alkenone MAR reflects primary productivity because these recalcitrant compounds are produced by certain species of haptophyte algae. Increased productivity and macronutrient (Si, P, N) availability with NHG onset are inferred from increased mean alkenone MAR and decreased sediment reflectance values (low L*; opal-rich sediments) after 2.73 Ma. Like sea surface cooling, the primary productivity and macronutrient proxies vary primarily at 41-kyr periodicity, with regular increases preceding glaciations. Finally, magnetic susceptibility/accumulation should reflect eolian deposition of dust from Asia--EAWM intensity. Increased magnetic accumulation also regularly precedes obliquity-paced glaciations, but with a particularly long lead. This unusual timing may result from contributions of other considerations besides EAWM intensity, such as pedogenic processes affecting oxide phases in Asia.

Comparison of children with autism spectrum disorder with and without schizophrenia spectrum traits: gender, season of birth, and mental health risk factors.

PubMed

Gadow, Kenneth D; DeVincent, Carla J

2012-11-01

Children with autism spectrum disorder (ASD) with and without co-occurring schizophrenia spectrum traits (SST) were examined for differences in co-occurring psychiatric symptoms, background characteristics, and mental health risk factors. Participating mothers and teachers completed a DSM-IV-referenced rating scale and a background questionnaire (mothers only) describing 147 children (6-12 years) with ASD. There was a clear pattern of group differences in co-occurring psychiatric symptom severity (+SST > SST-) and background characteristics. Children with impairing SST had more mental health risk factors. Girls were more likely to be classified SST according to mothers' ratings. Children born in spring-summer were more likely to be classified non-SST by teachers' ratings. Findings provide tentative evidence that SST may be a useful marker of behavioral heterogeneity within the ASD clinical phenotype.

Effect of Radiative Cooling on Cloud-SST Relationship within the Tropical Pacific Region

NASA Technical Reports Server (NTRS)

Sui, Chung-Hsiung; Ho, Chang-Hoi; Chou, Ming-Dah; Lau, Ka-Ming; Li, Xiao-Fan; Einaudi, Franco (Technical Monitor)

2000-01-01

A recent analysis found a negative correlation between the area-mean cloud amount and the corresponding mean Sea Surface Temperature (SST) within the cloudy areas. The SST-cloud relation becomes more evident when the SST contrast between warm pool and surrounding cold pool (DSST) in the tropical Pacific is stronger than normal. The above feature is related to the finding that the strength of subsidence over the cold pool is limited by radiative cooling because of its small variability. As a result, the area of radiatively-driven subsidence must expand in response to enhanced low-boundary forcing due to SST warming or enhanced basin-scale DSST. This leads to more cloud free regions and less cloudy regions. The increased ratio of cloud-free areas to cloudy areas leads to more high SST areas (>29.50C) due to enhanced solar radiation.

Article Errors in the English Writing of Saudi EFL Preparatory Year Students

ERIC Educational Resources Information Center

Alhaisoni, Eid; Gaudel, Daya Ram; Al-Zuoud, Khalid M.

2017-01-01

This study aims at providing a comprehensive account of the types of errors produced by Saudi EFL students enrolled in the preparatory year programe in their use of articles, based on the Surface Structure Taxonomies (SST) of errors. The study describes the types, frequency and sources of the definite and indefinite article errors in writing…

Progress in supersonic cruise aircraft technology

NASA Technical Reports Server (NTRS)

Driver, C.

1978-01-01

The supersonic cruise aircraft research program identified significant improvements in the technology areas of propulsion, aerodynamics, structures, takeoff and landing procedures, and advanced configuration concepts. Application of these technology areas to a commercial aircraft is discussed. An advanced SST family of aircraft which may be environmentally acceptable, have flexible range-payload capability, and be economically viable is projected.

Effects of the neuroprotective drugs somatostatin and brimonidine on retinal cell models of diabetic retinopathy.

PubMed

Beltramo, Elena; Lopatina, Tatiana; Mazzeo, Aurora; Arroba, Ana I; Valverde, Angela M; Hernández, Cristina; Simó, Rafael; Porta, Massimo

2016-12-01

Diabetic retinopathy is considered a microvascular disease, but recent evidence has underlined early involvement of the neuroretina with interactions between microvascular and neural alterations. Topical administration of somatostatin (SST), a neuroprotective molecule with antiangiogenic properties, prevents diabetes-induced retinal neurodegeneration in animals. The α 2 -adrenergic receptor agonist brimonidine (BRM) decreases vitreoretinal vascular endothelial growth factor and inhibits blood-retinal barrier breakdown in diabetic rats. However, SST and BRM effects on microvascular cells have not yet been studied. We investigated the behaviour of these drugs on the crosstalk between microvasculature and neuroretina. Expression of SST receptors 1-5 in human retinal pericytes (HRP) was checked. We subsequently evaluated the effects of diabetic-like conditions (high glucose and/or hypoxia) with/without SST/BRM on HRP survival. Endothelial cells (EC) and photoreceptors were maintained in the above conditions and their conditioned media (CM) used to culture HRP. Vice versa, HRP-CM was used on EC and photoreceptors. Survival parameters were assessed. HRP express the SST receptor 1 (SSTR1). Glucose fluctuations mimicking those occurring in diabetic subjects are more damaging for pericytes and photoreceptors than stable high glucose and hypoxic conditions. SST/BRM added to HRP in diabetic-like conditions decrease EC apoptosis. However, neither SST nor BRM changed the response of pericytes and neuroretina-vascular crosstalk under diabetic-like conditions. Retinal pericytes express SSTR1, indicating that they can be a target for SST. Exposure to SST/BRM had no adverse effects, direct or mediated by the neuroretina, suggesting that these molecules could be safely evaluated for the treatment of ocular diseases.

Impacts of SST Patterns on Rapid Intensification of Typhoon Megi (2010)

NASA Astrophysics Data System (ADS)

Kanada, Sachie; Tsujino, Satoki; Aiki, Hidenori; Yoshioka, Mayumi K.; Miyazawa, Yasumasa; Tsuboki, Kazuhisa; Takayabu, Izuru

2017-12-01

Typhoon Megi (2010), a very intense tropical cyclone with a minimum central pressure of 885 hPa, was characterized by especially rapid intensification. We investigated this intensification process by a simulation experiment using a high-resolution (0.02° × 0.02°) three-dimensional atmosphere-ocean coupled regional model. We also performed a sensitivity experiment with a time-fixed sea surface temperature (SST). The coupled model successfully simulated the minimum central pressure of Typhoon Megi, whereas the fixed SST experiment simulated an excessively low minimum central pressure of 839 hPa. The simulation results also showed a close relationship between the radial SST profiles and the rapid intensification process. Because the warm sea increased near-surface water vapor and hence the convective available potential energy, the high SST in the eye region facilitated tall and intense updrafts inside the radius of maximum wind speed and led to the start of rapid intensification. In contrast, high SST outside this radius induced local secondary updrafts that inhibited rapid intensification even if the mean SST in the core region exceeded 29.0°C. These secondary updrafts moved inward and eventually merged with the primary eyewall updrafts. Then the storm intensified rapidly when the high SST appeared in the eye region. Thus, the changes in the local SST pattern around the storm center strongly affected the rapid intensification process by modulating the radial structure of core convection. Our results also show that the use of a high-resolution three-dimensional atmosphere-ocean coupled model offers promise for improving intensity forecasts of tropical cyclones.

Modulating Effects of Mesoscale Oceanic Eddies on Sea Surface Temperature Response to Tropical Cyclones Over the Western North Pacific

NASA Astrophysics Data System (ADS)

Ma, Zhanhong; Fei, Jianfang; Huang, Xiaogang; Cheng, Xiaoping

2018-01-01

The impact of mesoscale oceanic eddies on the temporal and spatial characteristics of sea surface temperature (SST) response to tropical cyclones is investigated in this study based on composite analysis of cyclone-eddy interactions over the western North Pacific. The occurrence times of maximum cooling, recovery time, and spatial patterns of SST response are specially evaluated. The influence of cold-core eddies (CCEs) renders the mean occurrence time of maximum SST cooling to become about half a day longer than that in eddy-free condition, while warm-core eddies (WCEs) have little effect on this facet. The recovery time of SST cooling also takes longer in presence of CCEs, being overall more pronounced for stronger or slower tropical cyclones. The effect of WCEs on the recovery time is again not significant. The modulation of maximum SST decrease by WCEs for category 2-5 storms is found to be remarkable in the subtropical region but not evident in the tropical region, while the role of CCEs is remarkable in both regions. The CCEs are observed to change the spatial characteristics of SST response, with enhanced SST decrease initially at the right side of storm track. During the recovery period the strengthened SST cooling by CCEs propagates leftward gradually, with a feature similar as both the westward-propagating eddies and the recovery of cold wake. These results underscore the importance of resolving mesoscale oceanic eddies in coupled numerical models to improve the prediction of storm-induced SST response.

Biweekly Sea Surface Temperature over the South China Sea and its association with the Western North Pacific Summer Monsoon

NASA Astrophysics Data System (ADS)

Vaid, B. H.

2017-02-01

The association of the biweekly intraseasonal (BWI) oscillation in the Sea Surface Temperature (SST) over the South China Sea (SCS) and the Western North Pacific Summer Monsoon is authenticated using version 4 the Tropical Rainfall Measuring Mission Microwave Imager data (SST and rain) and heat fluxes from Ocean Atmosphere Flux project data during 1998-2012. The results suggest that the SCS involves ocean-atmosphere coupling on biweekly timescales. The positive biweekly SST anomalies lead the rain anomalies over the SCS by 3 days, with a significant correlation coefficient ( r = 0.6, at 99 % significance levels) between the SST-rain anomalies. It is evident from lead/lag correlation between biweekly SST and zonal wind shear that warm ocean surface induced by wind shear may contribute to a favorable condition of the convective activity over the SCS. The present study suggests that ocean-to-atmospheric processes induced by the BWI oscillation in the SCS SST results in enhanced sea level pressure and surface shortwave radiation flux during the summer monsoon. Besides, it is observed that the SCS BWI oscillation in the changes of SST causes a feedback in the atmosphere by modifying the atmospheric instability. This suggests that the active/break biweekly cycle of the SST over the SCS is related by sea level pressure, surface heat fluxes and atmospheric instability. The potential findings here indicate that the biweekly SST over the SCS play an important role in the eastward and the southward propagation of the biweekly anomalies in the Western North Pacific.

Asymmetric Response of the Equatorial Pacific SST to Climate Warming and Cooling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Fukai; Luo, Yiyong; Lu, Jian

The response of the equatorial Pacific Ocean to heat fluxes of equal amplitude but opposite sign is investigated using the Community Earth System Model (CESM). Results show a strong asymmetry in SST changes. In the eastern equatorial Pacific (EEP), the warming responding to the positive forcing exceeds the cooling to the negative forcing; while in the western equatorial Pacific (WEP), it is the other way around and the cooling surpasses the warming. This leads to a zonal dipole asymmetric structure, with positive values in the east and negative values in the west. A surface heat budget analysis suggests that themore » SST asymmetry is mainly resulted from the oceanic horizontal advection and vertical entrainment, with both of their linear and nonlinear components playing a role. For the linear component, its change appears to be more significant over the EEP (WEP) in the positive (negative) forcing scenario, favoring the seesaw pattern of the SST asymmetry. For the nonlinear component, its change acts to warm (cool) the EEP (WEP) in both scenarios, also favorable for the development of the SST asymmetry. Additional experiments with a slab ocean confirm the dominant role of ocean dynamical processes for this SST asymmetry. The net surface heat flux, in contrast, works to reduce the SST asymmetry through its shortwave radiation and latent heat flux components, with the former being related to the nonlinear relationship between SST and convection, and the latter being attributable to Newtonian damping and air-sea stability effects. The suppressing effect of shortwave radiation on SST asymmetry is further verified by partially coupled overriding experiments.« less

Asymmetric response of the equatorial Pacific SST to climate warming and cooling

NASA Astrophysics Data System (ADS)

Luo, Y.; Liu, F.; Lu, J.

2017-12-01

The response of the equatorial Pacific Ocean to heat fluxes of equal amplitude but opposite sign is investigated using the Community Earth System Model (CESM). Results show a strong asymmetry in SST changes. In the eastern equatorial Pacific (EEP), the warming responding to the positive forcing exceeds the cooling to the negative forcing; while in the western equatorial Pacific (WEP), it is the other way around and the cooling surpasses the warming. This leads to a zonal dipole asymmetric structure, with positive values in the east and negative values in the west. A surface heat budget analysis suggests that the SST asymmetry is mainly resulted from the oceanic horizontal advection and vertical entrainment, with both of their linear and nonlinear components playing a role. For the linear component, its change appears to be more significant over the EEP (WEP) in the positive (negative) forcing scenario, favoring the seesaw pattern of the SST asymmetry. For the nonlinear component, its change acts to warm (cool) the EEP (WEP) in both scenarios, also favorable for the development of the SST asymmetry. Additional experiments with a slab ocean confirm the dominant role of ocean dynamical processes for this SST asymmetry. The net surface heat flux, in contrast, works to reduce the SST asymmetry through its shortwave radiation and latent heat flux components, with the former being related to the nonlinear relationship between SST and convection, and the latter being attributable to Newtonian damping and air-sea stability effects. The suppressing effect of shortwave radiation on SST asymmetry is further verified by partially coupled overriding experiments.

Simulation of Rainfall Variability Over West Africa

NASA Astrophysics Data System (ADS)

Bader, J.; Latif, M.

The impact of sea surface temperature (SST) and vegetation on precipitation over West Africa is investigated with the atmospheric general circulation model ECHAM4.x/T42. Ensemble experiments -driven with observed SST- show that At- lantic SST has a significant influence on JJA precipitation over West Africa. Four- teen experiments were performed in which the climatological SST was enhanced or decreased by one Kelvin in certain ocean areas. Changing SST in the eastern tropi- cal Atlantic only caused significant changes along the Guinea Coast, with a positive SSTA increasing rainfall and a negative reducing it. The response was nearly linear. Changing SST in other ocean areas caused significant changes over West Africa, es- pecially in the Sahel area. The response is found to be non linear, with only negative SSTA leading to significant reduction in Sahel rainfall. Also, the impact of the SSTAs from the different ocean regions was not additive with respect to the rainfall. Four simulations with a coupled model (the simple dynamic vegetation model (SVege) and the ECHAM4-AGCM were coupled) were also performed, driven with observed SST from 1945 to 1998. The standard ECHAM-AGCM -forced by the same observed SST- was able to reproduce the drying trend from the fifties to the mid-eighties in the Sahel, but failed to mirror the magnitude of the rainfall anomalies. The coupled model was not only able to reproduce this drying trend, but was also able to better reproduce the amplitudes of the rainfall anomalies. The dynamic vegetation acted like an amplifier, increasing the SST induced rainfall anomalies.

Remote SST Forcing and Local Land-Atmosphere Moisture Coupling as Drivers of Amazon Temperature and Carbon Cycle Variability

NASA Astrophysics Data System (ADS)

Levine, P. A.; Xu, M.; Chen, Y.; Randerson, J. T.; Hoffman, F. M.

2017-12-01

Interannual variability of climatic conditions in the Amazon rainforest is associated with El Niño-Southern Oscillation (ENSO) and ocean-atmosphere interactions in the North Atlantic. Sea surface temperature (SST) anomalies in these remote ocean regions drive teleconnections with Amazonian surface air temperature (T), precipitation (P), and net ecosystem production (NEP). While SST-driven NEP anomalies have been primarily linked to T anomalies, it is unclear how much the T anomalies result directly from SST forcing of atmospheric circulation, and how much result indirectly from decreases in precipitation that, in turn, influence surface energy fluxes. Interannual variability of P associated with SST anomalies lead to variability in soil moisture (SM), which would indirectly affect T via partitioning of turbulent heat fluxes between the land surface and the atmosphere. To separate the direct and indirect influence of the SST signal on T and NEP, we performed a mechanism-denial experiment to decouple SST and SM anomalies. We used the Accelerated Climate Modeling for Energy (ACMEv0.3), with version 5 of the Community Atmosphere Model and version 4.5 of the Community Land Model. We forced the model with observed SSTs from 1982-2016. We found that SST and SM variability both contribute to T and NEP anomalies in the Amazon, with relative contributions depending on lag time and location within the Amazon basin. SST anomalies associated with ENSO drive most of the T variability at shorter lag times, while the ENSO-driven SM anomalies contribute more to T variability at longer lag times. SM variability and the resulting influence on T anomalies are much stronger in the eastern Amazon than in the west. Comparing modeled T with observations demonstrate that SST alone is sufficient for simulating the correct timing of T variability, but SM anomalies are necessary for simulating the correct magnitude of the T variability. Modeled NEP indicated that variability in carbon fluxes results from both SST and SM anomalies. As with T, SM anomalies affect NEP at a much longer lag time than SST anomalies. These results highlight the role of land-atmosphere coupling in driving climate variability within the Amazon, and suggest that land atmospheric coupling may amplify and delay carbon cycle responses to ocean-atmosphere teleconnections.

DOTA-Derivatives of Octreotide Dicarba-Analogs with High Affinity for Somatostatin sst2,5 Receptors.

PubMed

Pratesi, Alessandro; Ginanneschi, Mauro; Lumini, Marco; Papini, Anna M; Novellino, Ettore; Brancaccio, Diego; Carotenuto, Alfonso

2017-01-01

In vivo somatostatin receptor scintigraphy is a valuable method for the visualization of human endocrine tumors and their metastases. In fact, peptide ligands of somatostatin receptors (sst's) conjugated with chelating agents are in clinical use. We have recently developed octreotide dicarba-analogs, which show interesting binding profiles at sst's. In this context, it was mandatory to explore the possibility that our analogs could maintain their activity also upon conjugation with DOTA. In this paper, we report and discuss the synthesis, binding affinity and conformational preferences of three DOTA-conjugated dicarba-analogs of octreotide. Interestingly, two conjugated analogs exhibited nanomolar affinities on sst 2 and sst 5 somatostatin receptor subtypes.

A radiative transfer model for sea surface temperature retrieval for the along-track scanning radiometer

NASA Astrophysics Data System (ADS)

ZáVody, A. M.; Mutlow, C. T.; Llewellyn-Jones, D. T.

1995-01-01

The measurements made by the along-track scanning radiometer are now converted routinely into sea surface temperature (SST). The details of the atmospheric model which had been used for deriving the SST algorithms are given, together with tables of the coefficients in the algorithms for the different SST products. The accuracy of the retrieval under normal conditions and the effect of errors in the model on the retrieved SST are briefly discussed.

Interannual variability in stratiform cloudiness and sea surface temperature

NASA Technical Reports Server (NTRS)

Norris, Joel R.; Leovy, Conway B.

1994-01-01

Marine stratiform cloudiness (MSC)(stratus, stratocumulus, and fog) is widespread over subtropical oceans west of the continents and over midlatitude oceans during summer, the season when MSC has maximum influence on surface downward radiation and is most influenced by boundary-layer processes. Long-term datasets of cloudiness and sea surface teperature (SST) from surface observations from 1952 to 1981 are used to examine interannual variations in MSC and SST. Linear correlations of anomalies in seasonal MSC amount with seasonal SST anomalies are negative and significant in midlatitude and eastern subtropical oceans, especially during summer. Significant negative correlations between SST and nimbostratus and nonprecipitating midlevel cloudiness are also observed at midlatitudes during summer, suggesting that summer storm tracks shift from year to year following year-to-year meridional shifts in the SST gradient. Over the 30-yr period, there are significant upward trends in MSC amount over the northern midlatitude oceans and a significant downward trend off the coast of California. The highest correlations and trends occur where gradients in MSC and SST are strongest. During summer, correlations between SST and MSC anomalies peak at zero lag in midlatitudes where warm advection prevails, but SST lags MSC in subtropical regions where cold advection predominates. This difference is attributed to a tendency for anomalies in latent heat flux to compensate anomalies in surface downward radiation in warm advection regions but not in cold advection regions.

Hurricane destructive power predictions based on historical storm and sea surface temperature data.

PubMed

Bogen, Kenneth T; Jones, Edwin D; Fischer, Larry E

2007-12-01

Forecasting destructive hurricane potential is complicated by substantial, unexplained intraannual variation in storm-specific power dissipation index (PDI, or integrated third power of wind speed), and interannual variation in annual accumulated PDI (APDI). A growing controversy concerns the recent hypothesis that the clearly positive trend in North Atlantic Ocean (NAO) sea surface temperature (SST) since 1970 explains increased hurricane intensities over this period, and so implies ominous PDI and APDI growth as global warming continues. To test this "SST hypothesis" and examine its quantitative implications, a combination of statistical and probabilistic methods were applied to National Hurricane Center HURDAT best-track data on NAO hurricanes during 1880-2002, and corresponding National Oceanographic and Atmospheric Administration Extended Reconstruction SST estimates. Notably, hurricane behavior was compared to corresponding hurricane-specific (i.e., spatiotemporally linked) SST; previous similar comparisons considered only SST averaged over large NAO regions. Contrary to the SST hypothesis, SST was found to vary in a monthly pattern inconsistent with that of corresponding PDI, and to be at best weakly associated with PDI or APDI despite strong correlation with corresponding mean latitude (R(2)= 0.55) or with combined mean location and a approximately 90-year periodic trend (R(2)= 0.70). Over the last century, the lower 75% of APDIs appear randomly sampled from a nearly uniform distribution, and the upper 25% of APDIs from a nearly lognormal distribution. From the latter distribution, a baseline (SST-independent) stochastic model was derived predicting that over the next half century, APDI will not likely exceed its maximum value over the last half century by more than a factor of 1.5. This factor increased to 2 using a baseline model modified to assume SST-dependence conditioned on an upper bound of the increasing NAO SST trend observed since 1970. An additional model was developed that predicts PDI statistics conditional on APDI. These PDI and APDI models can be used to estimate upper bounds on indices of hurricane power likely to be realized over the next century, under divergent assumptions regarding SST influence.

The integrated value of sST2 and global longitudinal strain in the early stratification of patients with severe aortic valve stenosis: a translational imaging approach.

PubMed

Fabiani, Iacopo; Conte, Lorenzo; Pugliese, Nicola Riccardo; Calogero, Enrico; Barletta, Valentina; Di Stefano, Rossella; Santoni, Tatiana; Scatena, Cristian; Bortolotti, Uberto; Naccarato, Antonio Giuseppe; Petronio, Anna Sonia; Di Bello, Vitantonio

2017-12-01

Aortic valve stenosis (AVS) is associated with significant myocardial fibrosis (MF). Global longitudinal strain (GLS) is a sensible indicator of systolic dysfunction. ST2 is a member of the interleukin (IL)-1 receptor family and a modulator of hypertrophic and fibrotic responses. We aimed at assessing: (a) the association between adverse LV remodeling, LV functional parameters (including GLS) and sST2 level. (b) The association between MF (detected by endo-myocardial biopsy) and sST2 in patients with AVS undergoing surgical valve replacement. Twenty-two patients with severe AVS and preserved EF underwent aortic valve replacement. They performed laboratory analysis, including serum ST2 (sST2), echocardiography and inter-ventricular septum biopsy to assess MF (%). We included ten controls for comparison. Compared to controls, patients showed higher sST2 levels (p < 0.0001). sST2 showed correlation with Age (r = 0.58; p = 0.0004), E/e' average (r = 0.58; p = 0.0007), GLS (r = 0.61; p = 0.0002), LAVi (r = 0.51; p = 0.003), LVMi (r = 0.43; p = 0.01), sPAP (r = 0.36; p = 0.04) and SVi (r = -0.47; p < 0.005). No correlation was found between MF and sST2. At ROC analysis, a sST2 ≥ 284 ng/mL had the best accuracy to discriminate controls from patients with impaired GLS, i.e. GLS ≤ 17% (AUC 0.80; p = 0.003; sensitivity 95%; specificity 83%) and increased E/e' average (AUC 0.87; p = 0.0001; sensitivity 96%; specificity 74%). At multivariate regression analysis GLS resulted the only independent predictor of sST2 levels (R 2  = 0.35; p =  0.0004). Patients with severe AVS present elevated sST2 levels. LV GLS resulted the only independent predictor of sST2 levels.

Estimates of Single Sensor Error Statistics for the MODIS Matchup Database Using Machine Learning

NASA Astrophysics Data System (ADS)

Kumar, C.; Podesta, G. P.; Minnett, P. J.; Kilpatrick, K. A.

2017-12-01

Sea surface temperature (SST) is a fundamental quantity for understanding weather and climate dynamics. Although sensors aboard satellites provide global and repeated SST coverage, a characterization of SST precision and bias is necessary for determining the suitability of SST retrievals in various applications. Guidance on how to derive meaningful error estimates is still being developed. Previous methods estimated retrieval uncertainty based on geophysical factors, e.g. season or "wet" and "dry" atmospheres, but the discrete nature of these bins led to spatial discontinuities in SST maps. Recently, a new approach clustered retrievals based on the terms (excluding offset) in the statistical algorithm used to estimate SST. This approach resulted in over 600 clusters - too many to understand the geophysical conditions that influence retrieval error. Using MODIS and buoy SST matchups (2002 - 2016), we use machine learning algorithms (recursive and conditional trees, random forests) to gain insight into geophysical conditions leading to the different signs and magnitudes of MODIS SST residuals (satellite SSTs minus buoy SSTs). MODIS retrievals were first split into three categories: < -0.4 C, -0.4 C ≤ residual ≤ 0.4 C, and > 0.4 C. These categories are heavily unbalanced, with residuals > 0.4 C being much less frequent. Performance of classification algorithms is affected by imbalance, thus we tested various rebalancing algorithms (oversampling, undersampling, combinations of the two). We consider multiple features for the decision tree algorithms: regressors from the MODIS SST algorithm, proxies for temperature deficit, and spatial homogeneity of brightness temperatures (BTs), e.g., the range of 11 μm BTs inside a 25 km2 area centered on the buoy location. These features and a rebalancing of classes led to an 81.9% accuracy when classifying SST retrievals into the < -0.4 C and -0.4 C ≤ residual ≤ 0.4 C categories. Spatial homogeneity in BTs consistently appears as a very important variable for classification, suggesting that unidentified cloud contamination still is one of the causes leading to negative SST residuals. Precision and accuracy of error estimates from our decision tree classifier are enhanced using this knowledge.

Assessing the Contribution of Sea Surface Temperature and Salinity to Coral δ18O using a Weighted Forward Model

NASA Astrophysics Data System (ADS)

Horlick, K. A.; Thompson, D. M.; Anderson, D. M.

2015-12-01

The isotopic ratio of 16O/18O (δ18O) in coral carbonate skeletons is a robust, high-resolution proxy for sea surface temperature (SST) and sea surface salinity (SSS) variability predating the instrumental record. Although SST and δ18O-water (correlated to SSS) variability both contribute to the δ18O signal in the coral carbonate archive, the paucity and limited temporal span of SST and SSS instrumental observations limit the ability to differentiate respective SST and SSS contribution to each δ18O record. From instrumental datasets such as HadISST v.3, ERSST, SODA, and Delcroix (2011), we forward model the δ18O ("pseudoproxy") signal using the linear bivariate forward model from Thompson 2011 ("pseudoproxy"= a1(SST)+a2(SSS)). By iteratively weighting (between 0 and 1 by 0.005) the relative contribution of SST and SSS terms to the δ18O "pseudoproxy" following Gorman et al. 2012 method, we derive the percent contributions of SST and SSS to δ18O at each site based on the weights that produce the optimal correlation to the observed coral δ18O signal. A Monte Carlo analysis of error propagation in the weighted and unweighted pseudoproxy time series was used to determine how well the weighted and unweighted forward models captured observed δ18O variance. Across the south-western Pacific (40 sites) we found that SST contributes from less than 8 to more than 78% of the variance. This work builds upon this simple forward model of coral δ18O and improves our understanding of potential sources of differences in the observed and forward modeled δ18O variability. These results may also improve SST and SSS reconstructions from corals by highlighting the reef areas whose coral δ18O signal is most heavily influenced by SST and SSS respectively. Using an inverse approach, creating a transfer function, local SST and SSS could also be reconstructed based on the site-specific weights and observed coral δ18O time series.

South Asian Summer Monsoon Rainfall Variability and Trend: Its Links to Indo-Pacific SST Anomalies and Moist Processes

NASA Astrophysics Data System (ADS)

Prasanna, V.

2016-06-01

The warm (cold) phase of El Niño (La Niña) and its impact on all Indian Summer Monsoon rainfall (AISMR) relationship is explored for the past 100 years. The 103-year (1901-2003) data from the twentieth century reanalysis datasets (20CR) and other major reanalysis datasets for southwest monsoon season (JJAS) is utilized to find out the simultaneous influence of the El Niño Southern Oscillation (ENSO)-AISMR relationship. Two cases such as wet, dry monsoon years associated with ENSO(+) (El Niño), ENSO(-) (La Niña) and Non-ENSO (neutral) events have been discussed in detail using observed rainfall and three-dimensional 20CR dataset. The dry and wet years associated with ENSO and Non-ENSO periods show significant differences in the spatial pattern of rainfall associated with three-dimensional atmospheric composite, the 20CR dataset has captured the anomalies quite well. During wet (dry) years, the rainfall is high (low), i.e. 10 % above (below) average from the long-term mean and this wet or dry condition occur both during ENSO and Non-ENSO phases. The Non-ENSO year dry or wet composites are also focused in detail to understand, where do the anomalous winds come from unlike in the ENSO case. The moisture transport is coherent with the changes in the spatial pattern of AISMR and large-scale feature in the 20CR dataset. Recent 50-year trend (1951-2000) is also analyzed from various available observational and reanalysis datasets to see the influence of Indo-Pacific SST and moist processes on the South Asian summer monsoon rainfall trend. Apart from the Indo-Pacific sea surface temperatures (SST), the moisture convergence and moisture transport among India (IND), Equatorial Indian Ocean (IOC) and tropical western pacific (WNP) is also important in modifying the wet or dry cycles over India. The mutual interaction among IOC, WNP and IND in seasonal timescales is significant in modifying wet and dry cycles over the Indian region and the seasonal anomalies.

Identifying and Investigating the Late-1960s Interhemispheric SST Shift

NASA Astrophysics Data System (ADS)

Friedman, A. R.; Lee, S. Y.; Liu, Y.; Chiang, J. C. H.

2014-12-01

The global north-south interhemispheric sea surface temperature (SST) difference experienced a pronounced and rapid decrease in the late 1960s, which has been linked to drying in the Sahel, South Asia, and East Asia. However, some basic questions about the interhemispheric SST shift remain unresolved, including its scale and whether the constituent changes in different basins were coordinated. In this study, we systematically investigate the spatial and temporal behavior of the late-1960s interhemispheric SST shift using ocean surface and subsurface observations. We also evaluate potential mechanisms using control and specific-forcing CMIP5 simulations. Using a regime shift detection technique, we identify the late-1960s shift as the most prominent in the historical observational SST record. We additionally examine the corresponding changes in upper-ocean heat content and salinity associated with the shift. We find that there were coordinated upper-ocean cooling and freshening in the subpolar North Atlantic, the region of the largest-magnitude SST decrease during the interhemispheric shift. These upper-ocean changes correspond to a weakened North Atlantic thermohaline circulation (THC). However, the THC decrease does not fully account for the rapid global interhemispheric SST shift, particularly the warming in the extratropical Southern Hemisphere.

A prospective cohort study of digital cushion and corium thickness. Part 1: Associations with body condition, lesion incidence, and proximity to calving.

PubMed

Newsome, R F; Green, M J; Bell, N J; Bollard, N J; Mason, C S; Whay, H R; Huxley, J N

2017-06-01

Claw horn disruption lesions (CHDL) are a major cause of lameness in dairy cattle and are likely a result of excessive forces being applied to the germinal epithelium that produces the claw horn. The digital cushion is a connective tissue structure, containing depots of adipose tissue, that sits beneath the distal phalanx and has been shown to be thicker in fatter cows. Body condition score (BCS) loss is a risk factor for CHDL, and one possible explanation is that fat is mobilized from the digital cushion during negative energy balance, causing the digital cushion to thin and lose force-dissipating capacity, leading to disruption of claw horn growth. This prospective cohort study investigated the association between measures of body fat and sole soft tissue (SST) thickness (a combined measure of the corium and digital cushion beneath the distal phalanx) in a longitudinal manner. The SST of 179 cows in 2 high-yielding dairy herds were measured at 5 assessment points between 8 wk before and 35 wk postcalving. The BCS, back fat thickness (BFT), and lesion incidence were recorded. Data were analyzed in a 4-level mixed effects regression model, with the outcome being SST thickness beneath the flexor tuberosity of the distal phalanx. Data from 827 assessment points were available for analysis. The overall mean of SST was 4.99 mm (standard deviation: 0.95). The SST was thickest 8 wk before calving (5.22 mm, standard deviation: 0.91) and thinnest 1 wk postcalving (4.68 mm, standard deviation: 0.87), suggesting an effect of calving on SST. The BFT was positively correlated with SST in the model with a small effect size (a 10 mm decrease in BFT corresponded with a 0.13 mm decrease in SST), yet the nadir of BFT was 11.0 mm at 9 to 17 wk postcalving (when SST was ∼4.95 mm), rather than occurring with the nadir of SST immediately after calving. The SST also varied with other variables [e.g., cows that developed a sole ulcer or severe sole hemorrhage during the study had thinner SST (-0.24 mm)], except when a sole ulcer was present, when it was thicker (+0.53 mm). Cows that developed lesions had a thinner digital cushion before the lesion occurrence, which became thickened with sole ulcer presence, perhaps representing inflammation. Furthermore, although BFT was correlated with SST over time, SST may also have been influenced by other factors such as integrity of the suspensory apparatus, which could have a major effect on CHDL. Measures of body fat likely contributed to having thin SST, but other factors including calving, herd, and lesion presence also had an effect. The Authors. Published by the Federation of Animal Science Societies and Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).

SBSS Demonstrator: A design for efficient demonstration of Space-based Space Surveillance end-to-end capabilities

NASA Astrophysics Data System (ADS)

Utzmann, Jens; Flohrer, Tim; Schildknecht, Thomas; Wagner, Axel; Silha, Jiri; Willemsen, Philip; Teston, Frederic

This paper presents the capabilities of a Space-Based Space Surveillance (SBSS) demonstration mission for Space Surveillance and Tracking (SST) based on a micro-satellite platform. The results have been produced in the frame of ESA’s "Assessment Study for Space Based Space Surveillance Demonstration Mission" performed by the Airbus Defence and Space consortium. Space Surveillance and Tracking is part of Space Situational Awareness (SSA) and covers the detection, tracking and cataloguing of space debris and satellites. Derived SST services comprise a catalogue of these man-made objects, collision warning, detection and characterisation of in-orbit fragmentations, sub-catalogue debris characterisation, etc. The assessment of SBSS in a SST system architecture has shown that both an operational SBSS and also already a well-designed space-based demonstrator can provide substantial performance in terms of surveillance and tracking of beyond-LEO objects. Especially the early deployment of a demonstrator, possible by using standard equipment, could boost initial operating capability and create a self-maintained object catalogue. Furthermore, unique statistical information about small-size LEO debris (mm size) can be collected in-situ. Unlike classical technology demonstration missions, the primary goal is the demonstration and optimisation of the functional elements in a complex end-to-end chain (mission planning, observation strategies, data acquisition, processing and fusion, etc.) until the final products can be offered to the users. Also past and current missions by the US (SBV, SBSS) and Canada (Sapphire, NEOSSat) underline the advantages of space-based space surveillance. The presented SBSS system concept takes the ESA SST System Requirements (derived within the ESA SSA Preparatory Program) into account and aims at fulfilling SST core requirements in a stand-alone manner. Additionally, requirments for detection and characterisation of small-sized LEO debris are considered. The evaluation of the concept has shown that an according solution can be implemented with low technological effort and risk. The paper presents details of the system concept, candidate micro-satellite platforms, the observation strategy and the results of performance simulations for space debris coverage and cataloguing accuracy.

Topological Hall Effect in Skyrmions: A Nonequilibrium Coherent Transport Approach

NASA Astrophysics Data System (ADS)

Yin, Gen; Zang, Jiadong; Lake, Roger

2014-03-01

Skyrmion is a topological spin texture recently observed in many materials with broken inversion symmetry. In experiments, one effective method to detect the skyrmion crystal phase is the topological Hall measurement. At adiabatic approximation, previous theoretical studies show that the Hall signal is provided by an emergent magnetic field, which explains the topological Hall effect in the classical level. Motivated by the potential device application of skyrmions as digital bits, it is important to understand the topological Hall effect in the mesoscopic level, where the electron coherence should be considered. In this talk, we will discuss the quantum aspects of the topological Hall effect on a tight binding setup solved by nonequilibrium Green's function (NEGF). The charge distribution, Hall potential distribution, thermal broadening effect and the Hall resistivity are investigated in detail. The relation between the Hall resistance and the DM interaction is investigated. Driven by the spin transferred torque (SST), Skyrmion dynamics is previously studied within the adiabatic approximation. At the quantum transport level, this talk will also discuss the non-adiabatic effect in the skyrmion motion with the presence of the topological Hall effect. This material is based upon work supported by the National Science Foundation under Grant Nos. NSF 1128304 and NSF 1124733. It was also supported in part by FAME, one of six centers of STARnet, an SRC program sponsored by MARCO and DARPA.

The extreme 2014 flood in south-western Amazon basin: the role of tropical-subtropical South Atlantic SST gradient

NASA Astrophysics Data System (ADS)

Carlo Espinoza, Jhan; Marengo, José Antonio; Ronchail, Josyane; Molina Carpio, Jorge; Noriega Flores, Luís; Loup Guyot, Jean

2014-12-01

Unprecedented wet conditions are reported in the 2014 summer (December-March) in South-western Amazon, with rainfall about 100% above normal. Discharge in the Madeira River (the main southern Amazon tributary) has been 74% higher than normal (58 000 m3 s-1) at Porto Velho and 380% (25 000 m3 s-1) at Rurrenabaque, at the exit of the Andes in summer, while levels of the Rio Negro at Manaus were 29.47 m in June 2014, corresponding to the fifth highest record during the 113 years record of the Rio Negro. While previous floods in Amazonia have been related to La Niña and/or warmer than normal tropical South Atlantic, the 2014 rainfall and flood anomalies are associated with warm condition in the western Pacific-Indian Ocean and with an exceptionally warm Subtropical South Atlantic. Our results suggest that the tropical and subtropical South Atlantic SST gradient is a main driver for moisture transport from the Atlantic toward south-western Amazon, and this became exceptionally intense during summer of 2014.

Fast and Slow Responses of the South Asian Monsoon System to Anthropogenic Aerosols

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ganguly, Dilip; Rasch, Philip J.; Wang, Hailong

2012-09-25

Using a global climate model with fully predictive aerosol life cycle, we investigate the fast and slow responses of the South Asian monsoon system to anthropogenic aerosol forcing. Our results show that the feedbacks associated with sea surface temperature (SST) change caused by aerosols play a more important role than the aerosol's direct impact on radiation, clouds and land surface (rapid adjustments) in shaping the total equilibrium climate response of the monsoon system to aerosol forcing. Inhomogeneous SST cooling caused by anthropogenic aerosols eventually reduces the meridional tropospheric temperature gradient and the easterly shear of zonal winds over the region,more » slowing down the local Hadley cell circulation, decreasing the northward moisture transport, and causing a reduction in precipitation over South Asia. Although total responses in precipitation are closer to the slow responses in general, the fast component dominates over land areas north of 25°N. Our results also show an east-west asymmetry in the fast responses to anthropogenic aerosols causing increases in precipitation west of 80°E but decreases east of it.« less

Research on MMC-SST Oriented AC/DC Distribution System

NASA Astrophysics Data System (ADS)

Xie, Xifeng; Shi, Hua; Zuo, Jianglin; Zhang, Zhigang

2018-01-01

A modular multilevel converter-solid state transformer (MMC-SST) oriented AC/DC Distribution System is designed. Firstly, the topology structure is introduced, MMC is adopted in the input stage, multiple DC-DC converters are adopted in the isolation stage, and a Three-Phase Four-Leg inverter is adopted in the output stage. Then, the control strategy is analysed. Finally, simulation model and an experimental prototype of MMC-SST are built, simulation and experimental results show that topology and control strategy of MMC-SST are feasible.

Physical forcing of late summer chlorophyll a blooms in the oligotrophic eastern North Pacific

NASA Astrophysics Data System (ADS)

Toyoda, Takahiro; Okamoto, Suguru

2017-03-01

We investigated physical forcing of late summer chlorophyll a (chl a) blooms in the oligotrophic eastern North Pacific Ocean by using ocean reanalysis and satellite data. Relatively large chl a blooms as defined in this study occurred in August-October following sea surface temperature (SST) anomaly (SSTA) decreases, mixed layer deepening, and temperature and salinity increases at the bottom of the mixed layer. These physical conditions were apparently induced by the entrainment of subsurface water resulting from the destabilization of the surface layer caused by anomalous northward Ekman transport of subtropical waters of higher salinity. Salinity-normalized total alkalinity data provide supporting evidence for nutrient supply by the entrainment process. We next investigated the impact of including information about the entrainment on bloom identification. The results of analyses using reanalysis data and of those using only satellite data showed large SSTA decreases when the northward Ekman salinity transports were large, implying that the entrainment of subsurface water is well represented in both types of data. After surface-destabilizing conditions were established, relatively high surface chl a concentrations were observed. The use of SST information can further improve the detection of high chl a concentrations. Although the detection of high chl a concentrations would be enhanced by finer data resolution and the inclusion of biogeochemical parameters in the ocean reanalysis, our results obtained by using existing reanalysis data as well as recent satellite data are valuable for better understanding and prediction of lower trophic ecosystem variability.

A pilot of a video game (DDR) to promote physical activity and decrease sedentary screen time.

PubMed

Maloney, Ann E; Bethea, T Carter; Kelsey, Kristine S; Marks, Julie T; Paez, Sadye; Rosenberg, Angela M; Catellier, Diane J; Hamer, Robert M; Sikich, Linmarie

2008-09-01

We examined the feasibility of Dance Dance Revolution (DDR), a dance video game, in participants' homes, to increase physical activity (PA) and to decrease sedentary screen time (SST). Sixty children (7.5 +/- 0.5 years) were randomized in a 2:1 ratio to DDR or to wait-list control (10-week delay). DDR use was logged, PA was measured objectively by accelerometry. SST was self-reported at weeks 0 and 10. At week 28, after both groups had access to DDR, accelerometry and SST were repeated. Mean use of DDR was 89 +/- 82 (range 0-660 min) min per week (mpw). The DDR group showed increased vigorous PA and a reduction in light PA; the control group showed no increase in moderate and/or vigorous PA (MVPA) although they also had a reduction in light PA. Differences between the groups were not observed. The DDR group also reported a decrease in SST of -1.2 +/- 3.7 h per week (hpw) (P < 0.05), whereas the controls reported an increase of +3.0 +/- 7.7 hpw (nonsignificant). The difference in SST between the groups was significant, with less SST in the DDR group. Between weeks 10 and 28, numeric reductions in SST were reported in both groups. In the DDR group, SST at week 28 (8.8 +/- 6.0 hpw) was lower than baseline (10.5 +/- 5.5 hpw; P < 0.03). This pilot study suggests that DDR reduces SST and may facilitate slight increases in vigorous PA. Further study is needed to better characterize children and contexts in which DDR may promote a healthy lifestyle.

Shaping climate change in the North Atlantic sector: The role of the atmospheric response to local SST changes vs. large-scale changes

NASA Astrophysics Data System (ADS)

Hand, Ralf; Keenlyside, Noel; Omrani, Nour-Eddine; Greatbatch, Richard; Bader, Jürgen

2017-04-01

Climate change simulations robustly show a warming hole in the sub-polar North Atlantic that results from slowing of the AMOC countering the global warming signal. Here we investigate how the distinct SST spatial structures, which include a sharpening of the Gulf Stream SST gradients, influence climate change in the NA sector in winter. For this we analyse the RCP8.5 scenario simulation of the MPI Earth System Model. Additional sensitivity experiments with the atmospheric model component, ECHAM5, are performed to deconstruct the effect of the local spatial structure of the SST change from those arising from large-scale warming of the ocean, remote SST pattern changes and changed radiative forcings. The MPI model simulation shows a signifcant decrease in precipitation to the south of the GS extension region in the future, despite a strong increase in underlying SST. While directly to the north there is a significant increase in precipitation. These distinct features in the precipitation response over the North Atlantic result from the local SST. Over the Gulf Stream, the differential structure of the precipitation changes reflects the changes of the local SST gradients there. Over the subpolar gyre the increase in precipitation is partly suppressed. In this region the Subpolar Gyre the weakened AMOC causes a SST warming, that is much weaker than the warming other regions of the ocean show at the same latitude. The large-scale response, which includes the overall increase in precipitation over the NA is due to the overall warming, remote SSTs and/or directly connected to the radiative forcing.

El Niño–Southern Oscillation diversity and Southern Africa teleconnections during Austral Summer

USGS Publications Warehouse

Hoell, Andrew; Funk, Christopher C.; Magadzire, Tamuka; Zinke, Jens; Husak, Gregory J.

2014-01-01

A wide range of sea surface temperature (SST) expressions have been observed during the El Niño–Southern Oscillation events of 1950–2010, which have occurred simultaneously with different global atmospheric circulations. This study examines the atmospheric circulation and precipitation during December–March 1950–2010 over the African Continent south of 15∘S, a region hereafter known as Southern Africa, associated with eight tropical Pacific SST expressions characteristic of El Niño and La Niña events. The self-organizing map method along with a statistical distinguishability test was used to isolate the SST expressions of El Niño and La Niña. The seasonal precipitation forcing over Southern Africa associated with the eight SST expressions was investigated in terms of the horizontal winds, moisture budget and vertical motion. El Niño events, with warm SST across the east and central Pacific Ocean and warmer than average SST over the Indian Ocean, are associated with precipitation reductions over Southern Africa. The regional precipitation reductions are forced primarily by large-scale mid-tropospheric subsidence associated with anticyclonic circulation in the upper troposphere. El Niño events with cooler than average SST over the Indian Ocean are associated with precipitation increases over Southern Africa associated with lower tropospheric cyclonic circulation and mid-tropospheric ascent. La Niña events, with cool SST anomalies over the central Pacific and warm SST over the west Pacific and Indian Ocean, are associated with precipitation increases over Southern Africa. The regional precipitation increases are forced primarily by lower tropospheric cyclonic circulation, resulting in mid-tropospheric ascent and an increased flux of moisture into the region.

Assessing the Utility of Seasonal SST Forecasts to the Fisheries Management Process: a Pacific Sardine Case Study

NASA Astrophysics Data System (ADS)

Tommasi, D.; Stock, C. A.

2016-02-01

It is well established that environmental fluctuations affect the productivity of numerous fish stocks. Recent advances in prediction capability of dynamical global forecast systems, such as the state of the art NOAA Geophysical Fluid dynamics Laboratory (GFDL) 2.5-FLOR model, allow for climate predictions of fisheries-relevant variables at temporal scales relevant to the fishery management decision making process. We demonstrate that the GFDL FLOR model produces skillful seasonal SST anomaly predictions over the continental shelf , where most of the global fish yield is generated. The availability of skillful SST projections at this "fishery relevant" scale raises the potential for better constrained estimates of future fish biomass and improved harvest decisions. We assessed the utility of seasonal SST coastal shelf predictions for fisheries management using the case study of Pacific sardine. This fishery was selected because it is one of the few to already incorporate SST into its harvest guideline, and show a robust recruitment-SST relationship. We quantified the effectiveness of management under the status quo harvest guideline (HG) and under alternative HGs including future information at different levels of uncertainty. Usefulness of forecast SST to management was dependent on forecast uncertainty. If the standard deviation of the SST anomaly forecast residuals was less than 0.65, the alternative HG produced higher long-term yield and stock biomass, and reduced the probability of either catch or stock biomass falling below management-set threshold values as compared to the status quo. By contrast, probability of biomass falling to extremely low values increased as compared to the status quo for all alternative HGs except for a perfectly known future SST case. To safeguard against occurrence of such low probability but costly events, a harvest cutoff biomass also has to be implemented into the HG.

Effect of extreme sea surface temperature events on the demography of an age-structured albatross population.

PubMed

Pardo, Deborah; Jenouvrier, Stéphanie; Weimerskirch, Henri; Barbraud, Christophe

2017-06-19

Climate changes include concurrent changes in environmental mean, variance and extremes, and it is challenging to understand their respective impact on wild populations, especially when contrasted age-dependent responses to climate occur. We assessed how changes in mean and standard deviation of sea surface temperature (SST), frequency and magnitude of warm SST extreme climatic events (ECE) influenced the stochastic population growth rate log( λ s ) and age structure of a black-browed albatross population. For changes in SST around historical levels observed since 1982, changes in standard deviation had a larger (threefold) and negative impact on log( λ s ) compared to changes in mean. By contrast, the mean had a positive impact on log( λ s ). The historical SST mean was lower than the optimal SST value for which log( λ s ) was maximized. Thus, a larger environmental mean increased the occurrence of SST close to this optimum that buffered the negative effect of ECE. This 'climate safety margin' (i.e. difference between optimal and historical climatic conditions) and the specific shape of the population growth rate response to climate for a species determine how ECE affect the population. For a wider range in SST, both the mean and standard deviation had negative impact on log( λ s ), with changes in the mean having a greater effect than the standard deviation. Furthermore, around SST historical levels increases in either mean or standard deviation of the SST distribution led to a younger population, with potentially important conservation implications for black-browed albatrosses.This article is part of the themed issue 'Behavioural, ecological and evolutionary responses to extreme climatic events'. © 2017 The Author(s).

Interdecadal variability in pan-Pacific and global SST, revisited

NASA Astrophysics Data System (ADS)

Tung, Ka-Kit; Chen, Xianyao; Zhou, Jiansong; Li, King-Fai

2018-05-01

Interest in the "Interdecadal Pacific Oscillation (IPO)" in the global SST has surged recently on suggestions that the Pacific may be the source of prominent interdecadal variations observed in the global-mean surface temperature possibly through the mechanism of low-frequency modulation of the interannual El Nino-Southern Oscillation (ENSO) phenomenon. IPO was defined by performing empirical orthogonal function (EOF) analysis of low-pass filtered SST. The low-pass filtering creates its unique set of mathematical problems—in particular, mode mixing—and has led to some questions, many unanswered. To understand what these EOFs are, we express them first in terms of the recently developed pairwise rotated EOFs of the unfiltered SST, which can largely separate the high and low frequency bands without resorting to filtering. As reported elsewhere, the leading rotated dynamical modes (after the global warming trend) of the unfiltered global SST are: ENSO, Pacific Decadal Oscillation (PDO), and Atlantic Multidecadal Oscillation (AMO). IPO is not among them. The leading principal component (PC) of the low-pass filtered global SST is usually defined as IPO and it is seen to comprise of ENSO, PDO and AMO in various proportions depending on the filter threshold. With decadal filtering, the contribution of the interannual ENSO is understandably negligible. The leading dynamical mode of the filtered global SST is mostly AMO, and therefore should not have been called the Interdecadal "Pacific" Oscillation. The leading dynamical mode of the filtered pan-Pacific SST is mostly PDO. This and other low-frequency variability that have the action center in the Pacific, from either the pan-Pacific or global SST, have near zero global mean.

Comparison of intracorporeal single-stapled and double-stapled anastomosis in laparoscopic low anterior resection for rectal cancer: a case-control study.

PubMed

Kim, Hye Jin; Choi, Gyu-Seog; Park, Jun Seok; Park, Soo Yeun

2013-01-01

Recently, a single-stapled technique (SST) was performed instead of the conventional double-stapled technique (DST) in laparoscopic low anterior resection for anastomosis, by placement of intracorporeal purse-string sutures on the distal rectum with transanal specimen extraction. This study aimed to compare the short-term outcomes between the two anastomotic techniques. Between July 2007 and April 2010, 60 patients underwent SST by laparoscopic or robotic procedure. These patients were matched 1:2 by age, gender, date of surgery, and tumor stage with 120 patients who underwent conventional DST in laparoscopic low anterior resection. The robotic-assisted operative approach was used more frequently in the SST group than in the DST group (61.7 % vs. 3.3 %, p < 0.001). The mean operative time was 203.9 (range, 120-400) min for the SST group and 167.6 (range, 90-300) min for the DST group (p < 0.001). For specimen removal, the transanal approach was used in the SST group, while the transabdominal approach was used for the DST group. The pain score (visual analogue scale) of the SST group was lower (4.5 vs. 5.6, p < 0.001), although postoperative recovery was similar. Pathological examination revealed that the distal resection margin was significantly longer in the SST group (3.1 vs. 2.5 cm, p = 0.018). Postoperative morbidity including anastomotic leakage was similar in both groups. SST yielded equivalent short-term outcomes when compared to conventional DST and provided the advantages of minimal access and a longer distal resection margin. Therefore, SST in lower anterior resection may be a useful alternative to conventional DST.

Sr/Ca proxy sea-surface temperature reconstructions from modern and holocene Montastraea faveolata specimens from the Dry Tortugas National Park

USGS Publications Warehouse

Flannery, Jennifer A.; Poore, Richard Z.

2013-01-01

Sr/Ca ratios from skeletal samples from two Montastraea faveolata corals (one modern, one Holocene, ~6 Ka) from the Dry Tortugas National Park were measured as a proxy for sea-surface temperature (SST). We sampled coral specimens with a computer-driven triaxial micromilling machine, which yielded an average of 15 homogenous samples per annual growth increment. We regressed Sr/Ca values from resulting powdered samples against a local SST record to obtain a calibration equation of Sr/Ca = -0.0392 SST + 10.205, R = -0.97. The resulting calibration was used to generate a 47-year modern (1961-2008) and a 7-year Holocene (~6 Ka) Sr/Ca subannually resolved proxy record of SST. The modern M. faveolata yields well-defined annual Sr/Ca cycles ranging in amplitude from ~0.3 and 0.5 mmol/mol. The amplitude of ~0.3 to 0.5 mmol/mol equates to a 10-15°C seasonal SST amplitude, which is consistent with available local instrumental records. Summer maxima proxy SSTs calculated from the modern coral Sr/ Ca tend to be fairly stable: most SST maxima from 1961–2008 are 29°C ± 1°C. In contrast, winter minimum SST calculated in the 47-year modern time-series are highly variable, with a cool interval in the early to mid-1970s. The Holocene (~6 Ka) Montastraea faveolata coral also yields distinct annual Sr/Ca cycles with amplitudes ranging from ~0.3 to 0.6 mmol/mol. Absolute Sr/Ca values and thus resulting SST estimates over the ~7-year long record are similar to those from the modern coral. We conclude that Sr/Ca from Montastraea faveolata has high potential for developing subannually resolved Holocene SST records.

Improving Satellite Retrieved Infrared Sea Surface Temperatures in Aerosol-Contaminated Regions

NASA Astrophysics Data System (ADS)

Luo, B.; Minnett, P. J.; Szczodrak, G.; Kilpatrick, K. A.

2017-12-01

Infrared satellite observations of sea surface temperature (SST) have become essential for many applications in meteorology, climatology, and oceanography. Applications often require high accuracy SST data: for climate research and monitoring an absolute uncertainty of 0.1K and stability of better than 0.04K per decade are required. Tropospheric aerosol concentrations increase infrared signal attenuation and prevent the retrieval of accurate satellite SST. We compare satellite-derived skin SST with measurements from the Marine-Atmospheric Emitted Radiance Interferometer (M-AERI) deployed on ships during the Aerosols and Ocean Science Expeditions (AEROSE) and with quality-controlled drifter temperatures. After match-up with in-situ SST and filtering of cloud contaminated data, the results indicate that SST retrieved from MODIS (Moderate Resolution Imaging Spectroradiometer) aboard the Terra and Aqua satellites have negative (cool) biases compared to shipboard radiometric measurements. There is also a pronounced negative bias in the Saharan outflow area that can introduce SST errors >1 K at aerosol optical depths > 0.5. In this study, we present a new method to derive night-time Saharan Dust Index (SDI) algorithms based on simulated brightness temperatures at infrared wavelengths of 3.9, 10.8 and 12.0 μm, derived using RTTOV. We derived correction coefficients for Aqua MODIS measurements by regression of the SST errors against the SDI. The biases and standard deviations are reduced by 0.25K and 0.19K after the SDI correction. The goal of this study is to understand better the characteristics and physical mechanisms of aerosol effects on satellite retrieved infrared SST, as well as to derive empirical formulae for improved accuracies in aerosol-contaminated regions.

Octreotide promotes apoptosis in human somatotroph tumor cells by activating somatostatin receptor type 2.

PubMed

Ferrante, E; Pellegrini, C; Bondioni, S; Peverelli, E; Locatelli, M; Gelmini, P; Luciani, P; Peri, A; Mantovani, G; Bosari, S; Beck-Peccoz, P; Spada, A; Lania, A

2006-09-01

Somatostatin analogs currently used in the treatment of acromegaly and other neuroendocrine tumors inhibit hormone secretion and cell proliferation by binding to somatostatin receptor type (SST) 2 and 5. The antiproliferative pathways coupled to these receptors have been only partially characterized. The aim of this study was to evaluate the effect of octreotide and super selective SST2 (BIM23120) and SST5 (BIM23206) analogs on apoptotic activity and apoptotic gene expression in human somatotroph tumor cells. Eight somatotroph tumors expressing similar levels of SST2 and SST5 evaluated by real-time PCR and western blot analyses were included in the study. In cultured cells obtained from these tumors, octreotide induced a dose-dependent increase of caspase-3 activity (160+/-20% vs basal at 10 nM) and cleaved cytokeratin 18 levels (172+/-25% vs basal) at concentrations higher than 0.1 nM. This effect was due to SST2 activation since BIM23120 elicited comparable responses, while BIM23206 was ineffective. BIM23120-stimulated apoptosis was dependent on phosphatases, since it was abrogated by the inhibitor orthovanadate, and independent from the induction of apoptosis-related genes, such as p53, p63, p73, Bcl-2, Bax, BID, BIK, TNFSF8, and FADD. In somatotroph tumors, both BIM23120 and BIM2306 caused growth arrest as indicated by the increase in p27 and decrease in cyclin D1 expression. In conclusion, the present study showed that octreotide-induced apoptosis in human somatotroph tumor cells by activating SST2. This effect, together with the cytostatic action exerted by both SST2 and SST5 analogs, might account for the tumor shrinkage observed in acromegalic patients treated with long-acting somatostatin analogs.

Enhanced influence of early-spring tropical Indian Ocean SST on the following early-summer precipitation over Northeast China

NASA Astrophysics Data System (ADS)

Han, Tingting; He, Shengping; Wang, Huijun; Hao, Xin

2017-04-01

The relationship between the tropical Indian Ocean (TIO) and East Asian summer monsoon/precipitation has been documented in many studies. However, the precursor signals of summer precipitation in the TIO sea surface temperature (SST), which is important for climate prediction, have drawn little attention. This study identified a strong relationship between early-spring TIO SST and subsequent early-summer precipitation in Northeast China (NEC) since the late 1980s. For 1961-1986, the correlations between early-spring TIO SST and early-summer NEC precipitation were statistically insignificant; for 1989-2014, they were positively significant. Since the late 1980s, the early-spring positive TIO SST anomaly was generally followed by a significant anomalous anticyclone over Japan; that facilitated anomalous southerly winds over NEC, conveying more moisture from the North Pacific. Further analysis indicated that an early TIO SST anomaly showed robust persistence into early summer. However, the early-summer TIO SST anomaly displayed a more significant influence on simultaneous atmospheric circulation and further affected NEC precipitation since the late 1980s. In 1989-2014, the early-summer Hadley and Ferrell cell anomalies associated with simultaneous TIO SST anomaly were much more significant and extended further north to mid-latitudes, which provided a dynamic foundation for the TIO-mid-latitude connection. Correspondingly, the TIO SST anomaly could lead to significant divergence anomalies over the Mediterranean. The advections of vorticity by the divergent component of the flow effectively acted as a Rossby wave source. Thus, an apparent Rossby wave originated from the Mediterranean and propagated east to East Asia; that further influenced the NEC precipitation through modulation to the atmospheric circulation (e.g., surface wind, moisture, vertical motion).

SST cooling along coastal Java and Sumatra during positive Indian Ocean Dipole events

NASA Astrophysics Data System (ADS)

Delman, A. S.; McClean, J.; Sprintall, J.; Talley, L. D.; Bryan, F.; Johnson, B. K.; Carton, J.

2016-02-01

The evolution of positive Indian Ocean Dipole (pIOD) events is driven in part by anomalous SST cooling near the coasts of Java and Sumatra. However, the mechanisms and timeline of surface temperature changes near these two islands are distinct. Satellite data and mixed layer budgets in a forced ocean model simulation with 0.1° spatial resolution were used to characterize the dominant influences on SST in each region during pIOD events. Along the south coast of Java, where upwelling from southeasterly trade winds happens seasonally in June-September, strengthening/weakening of the trade winds has little effect on the interannual variability of SST. Instead, remotely-forced upwelling Kelvin waves are the primary mechanism for producing anomalous Java SST cooling in the early stages of a pIOD event. Other mechanisms that affect Java SST anomalies include inflows from the interior Indonesian Seas, mesoscale eddies, and air-sea heat fluxes; these influences can hasten the decay of cool Java SST anomalies and therefore may impact the strength and duration of pIOD events. Along the west coast of Sumatra, surface cooling is initially delayed by a deeper thermocline and a salinity-stratified barrier layer. Hence upwelling Kelvin waves do not substantially affect SST near Sumatra during the first 2-3 months of Java SST cooling; however, they do help drive surface cooling near Sumatra once the barrier layer has been sufficiently eroded by waters of decreasing temperature and increasing salinity. Upwelling Kelvin wave activity in the equatorial Indian Ocean starting in April is also shown to be a robust predictor of pIOD events later in the calendar year.

Preparation and biological evaluation of 64Cu-CB-TE2A-sst2-ANT, a somatostatin antagonist for PET imaging of somatostatin receptor-positive tumors.

PubMed

Wadas, Thaddeus J; Eiblmaier, Martin; Zheleznyak, Alexander; Sherman, Christopher D; Ferdani, Riccardo; Liang, Kexian; Achilefu, Samuel; Anderson, Carolyn J

2008-11-01

Recently, the somatostatin receptor subtype 2 (SSTR2) selective antagonist sst2-ANT was determined to have a high affinity for SSTR2. Additionally, 111In-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-sst2-ANT showed high uptake in an SSTR2-transfected, tumor-bearing mouse model and suggested that radiolabeled SSTR2 antagonists may be superior to agonists for imaging SSTR2-positive tumors. This report describes the synthesis and evaluation of 64Cu-CB-4,11-bis(carboxymethyl)-1,4,8,11-tetraazabicyclo[6.6.2]hexadecane-sst2-ANT (64Cu-CB-TE2A-sst2-ANT) as a PET radiopharmaceutical for the in vivo imaging of SSTR2-positive tumors. Receptor-binding studies were performed to determine the dissociation constant of the radiopharmaceutical 64Cu-CB-TE2A-sst2-ANT using AR42J rat pancreatic tumor cell membranes. The internalization of 64Cu-CB-TE2A-sst2-ANT was compared with that of the 64Cu-labeled agonist 64Cu-CB-TE2A-tyrosine3-octreotate (64Cu-CB-TE2A-Y3-TATE) in AR42J cells. Both radiopharmaceuticals were also compared in vivo through biodistribution studies using healthy rats bearing AR42J tumors, and small-animal PET/CT of 64Cu-CB-TE2A-sst2-ANT was performed. The dissociation constant value for the radiopharmaceutical was determined to be 26 +/- 2.4 nM, and the maximum number of binding sites was 23,000 fmol/mg. 64Cu-CB-TE2A-sst2-ANT showed significantly less internalization than did 64Cu-CB-TE2A-Y3-TATE at time points from 15 min to 4 h. Biodistribution studies revealed that the clearance of 64Cu-CB-TE2A-sst2-ANT from the blood was rapid, whereas the clearance of 64Cu-CB-TE2A-sst2-ANT from the liver and kidneys was more modest at all time points. Tumor-to-blood and tumor-to-muscle ratios were determined to be better for 64Cu-CB-TE2A-sst2-ANT than those for 64Cu-CB-TE2A-Y3-TATE at the later time points, although liver and kidney uptake was significantly higher. Small-animal imaging using 64Cu-CB-TE2A-sst2-ANT revealed excellent tumor-to-background contrast at 4 h after injection, and standardized uptake values remained high even after 24 h. The PET radiopharmaceutical 64Cu-CB-TE2A-sst2-ANT is an attractive agent, worthy of future study as a PET radiopharmaceutical for the imaging of somatostatin receptor-positive tumors.

The Mg - SST relationship in mollusc shells: is there a rule? Examples from three tropical species

NASA Astrophysics Data System (ADS)

Lazareth, C. E.; Guzmán, N.; Lecornec, F.; Cabioch, G.; Ortlieb, L.

2009-04-01

The geochemistry of mollusc shells is currently viewed as a powerful tool for paleoenvironmental reconstructions. Indeed, molluscs are ubiquitous animals, with a worldly geographical and environmental distribution, providing various environmental records. Moreover, mollusc shells are abundantly found in fossil and archaeological settings. In the paleoclimatic reconstructions, the sea-surface temperatures (SST) are a key parameter. If shell stable oxygen isotope signatures can provide accurate SST records, this proxy is also influenced by the water isotopic composition. To find another tracer which would depend on the SST solely, the relationship between Mg content changes in mollusc shell and SST has been investigated for a few years. Nevertheless, if the reliability of shell Mg as SST tracer has been proven in some species, this is clearly not a "universal" and definitive rule. To reconstruct the past tropical SSTs, Mg calibration studies were undertaken on Concholepas concholepas (gastropod, South America), Protothaca thaca (bivalve, South America) and Tridacna squamosa (bivalve, New Caledonia). The very high-resolution (infra-daily) analyses of the C. concholepas gastropod revealed a significant metabolism control, at the nyctemeral scale, on the Mg incorporation into the calcite shell layer. Over a two months period, the Mg fluctuations in C. concholepas shell do not match with the SST instrumental measurements. Mg content changes along the aragonitic shell growth axis of several living P. thaca from a same Peruvian site are significantly different indicating no relationship between Mg and SST. The Mg variations measured in a Chilean P. thaca shell are, surprisingly, similar to variations of the instrumental SST. Unless this quite reliable relationship between P. thaca shell and SST is confirmed, and that the inter-site difference in Mg response to environmental forcing is understood, P. thaca shell Mg cannot be used as SST proxy. Lastly, a preliminary work carried out on the external aragonitic shell layer of T. squamosa showed that, over 14 months of growth, Mg and SST are well conversely correlated but the seasonal cycle is interrupted by a Mg peak that corresponds to a shell growth anomaly. Additional studies, especially dedicated on anomalies-related Mg increases, must be performed to validate the T. squamosa shell as a reliable SST proxy. Considering previous works and the results presented here, one can definitively conclude that, at least, calibration procedures are indispensable before using Mg as a SST proxy in mollusc shells. In addition, further work specifically directed towards the role of the metabolism on the incorporation of Mg in mollusc shells could be the key to understand, and thus to use, this proxy for which, at the present time, no single rule is applicable to molluscs. Contribution of the CONCHAS (PNEDC), CENSOR (6th PCRD) and BioCalc (ESF) projects. "This study was financed and conducted in the frame of the EU-project CENSOR (Climate variability and El Nino Southern Oscillation: Impacts for natural resources and management, contract 511071) and is CENSOR publication 0375".

ENSO modulation of tropical Indian Ocean subseasonal variability

NASA Astrophysics Data System (ADS)

Jung, Eunsil; Kirtman, Ben P.

2016-12-01

In this study, we use 30 years of retrospective climate model forecasts and observational estimates to show that El Niño/Southern Oscillation (ENSO) affects the amplitude of subseasonal variability of sea surface temperature (SST) in the southwest Indian Ocean, an important Tropical Intraseasonal Oscillation (TISO) onset region. The analysis shows that deeper background mixed-layer depths and warmer upper ocean conditions during El Niño reduce the amplitude of the subseasonal SST variability over Seychelles-Chagos Thermocline Ridge (SCTR), which may reduce SST-wind coupling and the amplitude of TISO variability. The opposite holds for La Niña where the shallower mixed-layer depth enhances SST variability over SCTR, which may increase SST-wind coupling and the amplitude of TISO variability.

Variable cycle engines for advanced supersonic transports

NASA Technical Reports Server (NTRS)

Howlett, R. A.; Kozlowski, H.

1975-01-01

Variable Cycle Engines being studied for advanced commercial supersonic transports show potential for significant environmental and economic improvements relative to 1st generation SST engines. The two most promising concepts are: a Variable Stream Control Engine and a Variable Cycle Engine with a rear flow-control valve. Each concept utilizes variable components and separate burners to provide independent temperature and velocity control for two coannular flow streams. Unique fuel control techniques are combined with cycle characteristics that provide low fuel consumption, similar to a turbojet engine, for supersonic operation. This is accomplished while retaining the good subsonic performance features of a turbofan engine. A two-stream coannular nozzle shows potential to reduce jet noise to below FAR Part 36 without suppressors. Advanced burner concepts have the potential for significant reductions in exhaust emissions. In total, these unique engine concepts have the potential for significant overall improvements to the environmental and economic characteristics of advanced supersonic transports.

Reevaluation of mid-Pliocene North Atlantic sea surface temperatures

USGS Publications Warehouse

Robinson, Marci M.; Dowsett, Harry J.; Dwyer, Gary S.; Lawrence, Kira T.

2008-01-01

Multiproxy temperature estimation requires careful attention to biological, chemical, physical, temporal, and calibration differences of each proxy and paleothermometry method. We evaluated mid-Pliocene sea surface temperature (SST) estimates from multiple proxies at Deep Sea Drilling Project Holes 552A, 609B, 607, and 606, transecting the North Atlantic Drift. SST estimates derived from faunal assemblages, foraminifer Mg/Ca, and alkenone unsaturation indices showed strong agreement at Holes 552A, 607, and 606 once differences in calibration, depth, and seasonality were addressed. Abundant extinct species and/or an unrecognized productivity signal in the faunal assemblage at Hole 609B resulted in exaggerated faunal-based SST estimates but did not affect alkenone-derived or Mg/Ca–derived estimates. Multiproxy mid-Pliocene North Atlantic SST estimates corroborate previous studies documenting high-latitude mid-Pliocene warmth and refine previous faunal-based estimates affected by environmental factors other than temperature. Multiproxy investigations will aid SST estimation in high-latitude areas sensitive to climate change and currently underrepresented in SST reconstructions.

Western tropical Pacific multidecadal variability forced by the Atlantic multidecadal oscillation

PubMed Central

Sun, Cheng; Kucharski, Fred; Li, Jianping; Jin, Fei-Fei; Kang, In-Sik; Ding, Ruiqiang

2017-01-01

Observational analysis suggests that the western tropical Pacific (WTP) sea surface temperature (SST) shows predominant variability over multidecadal time scales, which is unlikely to be explained by the Interdecadal Pacific Oscillation. Here we show that this variability is largely explained by the remote Atlantic multidecadal oscillation (AMO). A suite of Atlantic Pacemaker experiments successfully reproduces the WTP multidecadal variability and the AMO–WTP SST connection. The AMO warm SST anomaly generates an atmospheric teleconnection to the North Pacific, which weakens the Aleutian low and subtropical North Pacific westerlies. The wind changes induce a subtropical North Pacific SST warming through wind–evaporation–SST effect, and in response to this warming, the surface winds converge towards the subtropical North Pacific from the tropics, leading to anomalous cyclonic circulation and low pressure over the WTP region. The warm SST anomaly further develops due to the SST–sea level pressure–cloud–longwave radiation positive feedback. Our findings suggest that the Atlantic Ocean acts as a key pacemaker for the western Pacific decadal climate variability. PMID:28685765

Decadal changes in South Pacific sea surface temperatures and the relationship to the Pacific decadal oscillation and upper ocean heat content

NASA Astrophysics Data System (ADS)

Linsley, Braddock K.; Wu, Henry C.; Dassié, Emilie P.; Schrag, Daniel P.

2015-04-01

Decadal changes in Pacific sea surface temperatures (SSTs) and upper ocean heat content (OHC) remain poorly understood. We present an annual average composite coral Sr/Ca-derived SST time series extending back to 1791 from Fiji, Tonga, and Rarotonga (FTR) in the Pacific Decadal Oscillation (PDO) sensitive region of the southwest Pacific. Decadal SST maxima between 1805 and 1830 Common Era (C.E.) indicate unexplained elevated SSTs near the end of the Little Ice Age. The mean period of decadal SST variability in this region has a period near 25 years. Decades of warmer (cooler) FTR SST co-occur with PDO negative (positive) phases since at least ~1930 C.E. and positively correlate with South Pacific OHC (0-700 m). FTR SST is also inversely correlated with decadal changes in equatorial Pacific SST as measured by coral Sr/Ca. Collectively, these results support the fluctuating trade wind-shallow meridional overturning cell mechanism for decadal modulation of Pacific SSTs and OHC.

Relationships of Upper Tropospheric Water Vapor, Clouds and SST: MLS Observations, ECMWF Analyses and GCM Simulations

NASA Technical Reports Server (NTRS)

Su, Hui; Waliser, Duane E.; Jiang, Jonathan H.; Li, Jui-lin; Read, William G.; Waters, Joe W.; Tompkins, Adrian M.

2006-01-01

The relationships of upper tropospheric water vapor (UTWV), cloud ice and sea surface temperature (SST) are examined in the annual cycles of ECMWF analyses and simulations from 15 atmosphere-ocean coupled models which were contributed to the IPCC AR4. The results are compared with the observed relationships based on UTWV and cloud ice measurements from MLS on Aura. It is shown that the ECMWF analyses produce positive correlations between UTWV, cloud ice and SST, similar to the MLS data. The rate of the increase of cloud ice and UTWV with SST is about 30% larger than that for MLS. For the IPCC simulations, the relationships between UTWV, cloud ice and SST are qualitatively captured. However, the magnitudes of the simulated cloud ice show a considerable disagreement between models, by nearly a factor of 10. The amplitudes of the approximate linear relations between UTWV, cloud ice and SST vary by a factor up to 4.

Sea Surface Temperature Products and Research Associated with GHRSST

NASA Astrophysics Data System (ADS)

Kaiser-Weiss, Andrea K.; Minnett, Peter J.; Kaplan, Alexey; Wick, Gary A.; Castro, Sandra; Llewellyn-Jones, David; Merchant, Chris; LeBorgne, Pierre; Beggs, Helen; Donlon, Craig J.

2012-03-01

GHRSST serves its user community through the specification of operational Sea Surface Temperature (SST) products (Level 2, Level 3 and Level 4) based on international consensus. Providers of SST data from individual satellites create and deliver GHRSST-compliant near-real time products to a global GHRSST data assembly centre and a long-term stewardship facility. The GHRSST-compliant data include error estimates and supporting data for interpretation. Groups organised within GHRSST perform research on issues relevant to applying SST for air-sea exchange, for instance the Diurnal Variability Working Group (DVWG) analyses the evolution of the skin temperature. Other GHRSST groups concentrate on improving the SST estimate (Estimation and Retrievals Working Group EARWiG) and on improving the error characterization, (Satellite SST Validation Group, ST-VAL) and on improving the methods for SST analysis (Inter-Comparison Technical Advisory Group, IC-TAG). In this presentation we cover the data products and the scientific activities associated with GHRSST which might be relevant for investigating ocean-atmosphere interactions.

Combined effects of recent Pacific cooling and Indian Ocean warming on the Asian monsoon.

PubMed

Ueda, Hiroaki; Kamae, Youichi; Hayasaki, Masamitsu; Kitoh, Akio; Watanabe, Shigeru; Miki, Yurisa; Kumai, Atsuki

2015-11-13

Recent research indicates that the cooling trend in the tropical Pacific Ocean over the past 15 years underlies the contemporaneous hiatus in global mean temperature increase. During the hiatus, the tropical Pacific Ocean displays a La Niña-like cooling pattern while sea surface temperature (SST) in the Indian Ocean has continued to increase. This SST pattern differs from the well-known La Niña-induced basin-wide cooling across the Indian Ocean on the interannual timescale. Here, based on model experiments, we show that the SST pattern during the hiatus explains pronounced regional anomalies of rainfall in the Asian monsoon region and thermodynamic effects due to specific humidity change are secondary. Specifically, Indo-Pacific SST anomalies cause convection to intensify over the tropical western Pacific, which in turn suppresses rainfall in mid-latitude East Asia through atmospheric teleconnection. Overall, the tropical Pacific SST effect opposes and is greater than the Indian Ocean SST effect.

Mid-Piacenzian sea surface temperature record from ODP Site 1115 in the western equatorial Pacific

USGS Publications Warehouse

Stoll, Danielle

2010-01-01

Planktic foraminifer assemblages and alkenone unsaturation ratios have been analyzed for the mid-Piacen-zian (3.3 to 2.9 Ma) section of Ocean Drilling Program (ODP) Site 1115B, located in the western equatorial Pacific off the coast of New Guinea. Cold and warm season sea surface temperature (SST) estimates were determined using a modern analog technique. ODP Site 1115 is located just south of the transition between the planktic foraminifer tropical and subtropical faunal provinces and approximates the southern boundary of the western equatorial Pacific (WEP) warm pool. Comparison of the faunal and alkenone SST estimates (presented here) with an existing nannofossil climate proxy shows similar trends. Results of this analysis show increased seasonal variability during the middle of the sampled section (3.22 to 3.10 Ma), suggesting a possible northward migration of both the subtropical faunal province and the southern boundary of the WEP warm pool.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

This volume contains the interim change notice for sample preparation methods. Covered are: acid digestion for metals analysis, fusion of Hanford tank waste solids, water leach of sludges/soils/other solids, extraction procedure toxicity (simulate leach in landfill), sample preparation for gamma spectroscopy, acid digestion for radiochemical analysis, leach preparation of solids for free cyanide analysis, aqueous leach of solids for anion analysis, microwave digestion of glasses and slurries for ICP/MS, toxicity characteristic leaching extraction for inorganics, leach/dissolution of activated metal for radiochemical analysis, extraction of single-shell tank (SST) samples for semi-VOC analysis, preparation and cleanup of hydrocarbon- containing samples for VOCmore » and semi-VOC analysis, receiving of waste tank samples in onsite transfer cask, receipt and inspection of SST samples, receipt and extrusion of core samples at 325A shielded facility, cleaning and shipping of waste tank samplers, homogenization of solutions/slurries/sludges, and test sample preparation for bioassay quality control program.« less

Pronounced zonal heterogeneity in Eocene southern high-latitude sea surface temperatures.

PubMed

Douglas, Peter M J; Affek, Hagit P; Ivany, Linda C; Houben, Alexander J P; Sijp, Willem P; Sluijs, Appy; Schouten, Stefan; Pagani, Mark

2014-05-06

Paleoclimate studies suggest that increased global warmth during the Eocene epoch was greatly amplified at high latitudes, a state that climate models cannot fully reproduce. However, proxy estimates of Eocene near-Antarctic sea surface temperatures (SSTs) have produced widely divergent results at similar latitudes, with SSTs above 20 °C in the southwest Pacific contrasting with SSTs between 5 and 15 °C in the South Atlantic. Validation of this zonal temperature difference has been impeded by uncertainties inherent to the individual paleotemperature proxies applied at these sites. Here, we present multiproxy data from Seymour Island, near the Antarctic Peninsula, that provides well-constrained evidence for annual SSTs of 10-17 °C (1σ SD) during the middle and late Eocene. Comparison of the same paleotemperature proxy at Seymour Island and at the East Tasman Plateau indicate the presence of a large and consistent middle-to-late Eocene SST gradient of ∼7 °C between these two sites located at similar paleolatitudes. Intermediate-complexity climate model simulations suggest that enhanced oceanic heat transport in the South Pacific, driven by deep-water formation in the Ross Sea, was largely responsible for the observed SST gradient. These results indicate that very warm SSTs, in excess of 18 °C, did not extend uniformly across the Eocene southern high latitudes, and suggest that thermohaline circulation may partially control the distribution of high-latitude ocean temperatures in greenhouse climates. The pronounced zonal SST heterogeneity evident in the Eocene cautions against inferring past meridional temperature gradients using spatially limited data within given latitudinal bands.

Pronounced zonal heterogeneity in Eocene southern high-latitude sea surface temperatures

PubMed Central

Douglas, Peter M. J.; Affek, Hagit P.; Ivany, Linda C.; Houben, Alexander J. P.; Sijp, Willem P.; Sluijs, Appy; Schouten, Stefan; Pagani, Mark

2014-01-01

Paleoclimate studies suggest that increased global warmth during the Eocene epoch was greatly amplified at high latitudes, a state that climate models cannot fully reproduce. However, proxy estimates of Eocene near-Antarctic sea surface temperatures (SSTs) have produced widely divergent results at similar latitudes, with SSTs above 20 °C in the southwest Pacific contrasting with SSTs between 5 and 15 °C in the South Atlantic. Validation of this zonal temperature difference has been impeded by uncertainties inherent to the individual paleotemperature proxies applied at these sites. Here, we present multiproxy data from Seymour Island, near the Antarctic Peninsula, that provides well-constrained evidence for annual SSTs of 10–17 °C (1σ SD) during the middle and late Eocene. Comparison of the same paleotemperature proxy at Seymour Island and at the East Tasman Plateau indicate the presence of a large and consistent middle-to-late Eocene SST gradient of ∼7 °C between these two sites located at similar paleolatitudes. Intermediate-complexity climate model simulations suggest that enhanced oceanic heat transport in the South Pacific, driven by deep-water formation in the Ross Sea, was largely responsible for the observed SST gradient. These results indicate that very warm SSTs, in excess of 18 °C, did not extend uniformly across the Eocene southern high latitudes, and suggest that thermohaline circulation may partially control the distribution of high-latitude ocean temperatures in greenhouse climates. The pronounced zonal SST heterogeneity evident in the Eocene cautions against inferring past meridional temperature gradients using spatially limited data within given latitudinal bands. PMID:24753570

A seasonal forecast scheme for the Inner Mongolia spring drought - Part-I: dynamic characteristics of the atmospheric circulation and forecast signals

NASA Astrophysics Data System (ADS)

Gao, Tao; Si, Yaobing; Yu, Xiao; Wulan; Yang, Peng; Gao, Jing

2018-02-01

This study analyzed the atmospheric evolutionary characteristics of insufficient rainfall that leads to spring drought in Inner Mongolia, China. The results revealed that a weakened western Pacific subtropical high and an enlarged North Polar vortex with a western position of the East Asian trough generally result in unfavorable moisture transportation for spring precipitation in IM. It was found that an abnormal sea surface temperature in several crucial ocean areas triggers an irregular atmospheric circulation over the Eurasian continent and the Pacific region. Lower sea surface temperature (SST) during the previous autumn over tropical regions of the central-eastern Pacific and Indian oceans induce a strong Walker circulation, corresponding to a weak and southeastward-retreating subtropical high over the western Pacific during the following winter and spring. Another crucial area is the central region of the North Atlantic Ocean. Abnormally low SST of the ocean area during the preceding autumn causes the Scandinavian teleconnection pattern (the index of which is issued on the website of the Climate Prediction Center, USA) changes to a positive phase, which leads to a weak westerly over the Eurasian continent. In this case, the easterly over the North Pole becomes stronger than normal, resulting in an extended North Polar vortex during the following spring. In addition, SST differences during the previous December between the middle-eastern tropical and the northwestern regions of the Pacific Ocean reflect variations of the Pacific Decadal Oscillation, causing the East Asian trough to move to a western position during the following spring.

Turbulence Model Behavior in Low Reynolds Number Regions of Aerodynamic Flowfields

NASA Technical Reports Server (NTRS)

Rumsey, Christopher L.; Spalart, Philippe R.

2008-01-01

The behaviors of the widely-used Spalart-Allmaras (SA) and Menter shear-stress transport (SST) turbulence models at low Reynolds numbers and under conditions conducive to relaminarization are documented. The flows used in the investigation include 2-D zero pressure gradient flow over a flat plate from subsonic to hypersonic Mach numbers, 2-D airfoil flow from subsonic to supersonic Mach numbers, 2-D subsonic sink-flow, and 3-D subsonic flow over an infinite swept wing (particularly its leading-edge region). Both models exhibit a range over which they behave transitionally in the sense that the flow is neither laminar nor fully turbulent, but these behaviors are different: the SST model typically has a well-defined transition location, whereas the SA model does not. Both models are predisposed to delayed activation of turbulence with increasing freestream Mach number. Also, both models can be made to achieve earlier activation of turbulence by increasing their freestream levels, but too high a level can disturb the turbulent solution behavior. The technique of maintaining freestream levels of turbulence without decay in the SST model, introduced elsewhere, is shown here to be useful in reducing grid-dependence of the model's transitional behavior. Both models are demonstrated to be incapable of predicting relaminarization; eddy viscosities remain weakly turbulent in accelerating or laterally-strained boundary layers for which experiment and direct simulations indicate turbulence suppression. The main conclusion is that these models are intended for fully turbulent high Reynolds number computations, and using them for transitional (e.g., low Reynolds number) or relaminarizing flows is not appropriate.

Turbulence Model Behavior in Low Reynolds Number Regions of Aerodynamic Flowfields

NASA Technical Reports Server (NTRS)

Rumsey, Christopher L.; Spalart, Philippe R.

2008-01-01

The behaviors of the widely-used Spalart-Allmaras (SA) and Menter shear-stress transport (SST) turbulence models at low Reynolds numbers and under conditions conducive to relaminarization are documented. The flows used in the investigation include 2-D zero pressure gradient flow over a flat plate from subsonic to hypersonic Mach numbers, 2-D airfoil flow from subsonic to supersonic Mach numbers, 2-D subsonic sink-flow, and 3-D subsonic flow over an infinite swept wing (particularly its leading-edge region). Both models exhibit a range over which they behave 'transitionally' in the sense that the flow is neither laminar nor fully turbulent, but these behaviors are different: the SST model typically has a well-defined transition location, whereas the SA model does not. Both models are predisposed to delayed activation of turbulence with increasing freestream Mach number. Also, both models can be made to achieve earlier activation of turbulence by increasing their freestream levels, but too high a level can disturb the turbulent solution behavior. The technique of maintaining freestream levels of turbulence without decay in the SST model, introduced elsewhere, is shown here to be useful in reducing grid-dependence of the model's transitional behavior. Both models are demonstrated to be incapable of predicting relaminarization; eddy viscosities remain weakly turbulent in accelerating or laterally-strained boundary layers for which experiment and direct simulations indicate turbulence suppression. The main conclusion is that these models are intended for fully turbulent high Reynolds number computations, and using them for transitional (e.g., low Reynolds number) or relaminarizing flows is not appropriate.

The role of SST on the South American atmospheric circulation during January, February and March 2001

NASA Astrophysics Data System (ADS)

Drumond, Anita Rodrigues De Moraes; Ambrizzi, Tércio

2005-06-01

Precipitation deficits were observed over southeastern, northeastern and Central Brazil during the 2001 Austral Summer. They contributed to the worsening of the energy crisis that was occurring in the country. A low-level anomalous anticyclonic circulation observed over eastern Brazil enhanced the deviation of moisture transport that usually occurs from the Amazon Basin to southeastern Brazil and inhibited the occurrence of South Atlantic Convergence Zone events in that period. However, an anomalous low-level northerly moisture flux was observed over the La Plata Basin, and positive precipitation anomalies occurred over Bolivia, Paraguay, northeastern Argentina and southern Brazil. Using the ensemble technique, a numerical study was carried out to investigate the role of different sea surface temperature (SST) forcings observed over this anomalous South American atmospheric circulation. Reynolds SST monthly means were used as boundary conditions to study the influence of South Atlantic, South Indian, South Pacific and Equatorial Pacific oceans. The simulations were run from September 2000 to April 2001 using the Community Climate Model version 3.6 General Circulation Model. Ten integrations using different initial conditions were done to each experiment. Numerical experiments suggested that the combined influence of South Pacific and Equatorial Pacific oceans could be responsible for the drought observed over Central Brazil. These experiments simulated the low-level anticyclonic anomaly observed over eastern Brazil. However, both experiments have poorly reproduced the intensity of the anomalous low-level northerly moisture flux observed over the La Plata Basin. Therefore, the intensity of the simulated precipitation anomalies over the subtropical regions was much weaker than observed.

[Support for Adult ASD in Medical Rework Program: Mutual Communication Program and Psychodrama].

PubMed

Yokoyama, Motonori

2015-01-01

While carrying out the Medical Rework Program, we realized the necessity for a supplementary medical treatment program aimed at adult ASD. Consequently, we started the Mutual Communication Program, which consists of standard SST and the new element of psychodrama. As a result, 32 participants have returned to their workplace in the three-year period, and the rate of successfully continuing to work was 93.8% at the time of the investigation. Various psychological tests also indicated significant improvement. In this article, we present a case study, explain psychodrama techniques employed in the program, and discuss their usefulness. The results suggest that psychodrama is a very effective assistive technique when the characteristics of ASD are taken into consideration.

Midlatitude atmosphere-ocean interaction during El Nino. Part I. The north Pacific ocean

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alexander, M.A.

Atmosphere-ocean modeling experiments are used to investigate the formation of sea surface temperature (SST) anomalies in the North Pacific Ocean during fall and winter of the El Nino year. Experiments in which the NCAR Community Climate Model (CCM) surface fields are used to force a mixed-layer ocean model in the North Pacific (no air-sea feedback) are compared to simulations in which the CCM and North Pacific Ocean model are coupled. Anomalies in the atmosphere and the North Pacific Ocean during El Nino are obtained from the difference between simulations with and without prescribed warm SST anomalies in the tropical Pacific.more » In both the forced and coupled experiments, the anomaly pattern resembles a composite of the actual SST anomaly field during El Nino: warm SSTs develop along the coast of North America and cold SSTs form in the central Pacific. In the coupled simulations, air-sea interaction results in a 25% to 50% reduction in the magnitude of the SST and mixed-layer depth anomalies, resulting in more realistic SST fields. Coupling also decreases the SST anomaly variance; as a result, the anomaly centers remain statistically significant even though the magnitude of the anomalies is reduced. Three additional sensitivity studies indicate that air-sea feedback and entrainment act to damp SST anomalies while Ekman pumping has a negligible effect on mixed-layer depth and SST anomalies in midatitudes.« less

Forecasting decadal changes in sea surface temperatures and coral bleaching within a Caribbean coral reef

NASA Astrophysics Data System (ADS)

Li, Angang; Reidenbach, Matthew A.

2014-09-01

Elevated sea surface temperature (SST) caused by global warming is one of the major threats to coral reefs. While increased SST has been shown to negatively affect the health of coral reefs by increasing rates of coral bleaching, how changes to atmospheric heating impact SST distributions, modified by local flow environments, has been less understood. This study aimed to simulate future water flow patterns and water surface heating in response to increased air temperature within a coral reef system in Bocas del Toro, Panama, located within the Caribbean Sea. Water flow and SST were modeled using the Delft3D-FLOWcomputer simulation package. Locally measured physical parameters, including bathymetry, astronomic tidal forcing, and coral habitat distribution were input into the model and water flow, and SST was simulated over a four-month period under present day, as well as projected warming scenarios in 2020s, 2050s, and 2080s. Changes in SST, and hence the thermal stress to corals, were quantified by degree heating weeks. Results showed that present-day reported bleaching sites were consistent with localized regions of continuous high SST. Regions with highest SST were located within shallow coastal sites adjacent to the mainland or within the interior of the bay, and characterized by low currents with high water retention times. Under projected increases in SSTs, shallow reef areas in low flow regions were found to be hot spots for future bleaching.

Novel, potent, and radio-iodinatable somatostatin receptor 1 (sst1) selective analogues.

PubMed

Erchegyi, Judit; Cescato, Renzo; Grace, Christy Rani R; Waser, Beatrice; Piccand, Véronique; Hoyer, Daniel; Riek, Roland; Rivier, Jean E; Reubi, Jean Claude

2009-05-14

The proposed sst(1) pharmacophore (J. Med. Chem. 2005, 48, 523-533) derived from the NMR structures of a family of mono- and dicyclic undecamers was used to design octa-, hepta-, and hexamers with high affinity and selectivity for the somatostatin sst(1) receptor. These compounds were tested for their in vitro binding properties to all five somatostatin (SRIF) receptors using receptor autoradiography; those with high SRIF receptor subtype 1 (sst(1)) affinity and selectivity were shown to be agonists when tested functionally in a luciferase reporter gene assay. Des-AA(1,4-6,10,12,13)-[DTyr(2),DAgl(NMe,2naphthoyl)(8),IAmp(9)]-SRIF-Thr-NH(2) (25) was radio-iodinated ((125)I-25) and specifically labeled sst(1)-expressing cells and tissues. 3D NMR structures were calculated for des-AA(1,4-6,10,12,13)-[DPhe(2),DTrp(8),IAmp(9)]-SRIF-Thr-NH(2) (16), des-AA(1,2,4-6,10,12,13)-[DAgl(NMe,2naphthoyl)(8),IAmp(9)]-SRIF-Thr-NH(2) (23), and des-AA(1,2,4-6,10,12,13)-[DAgl(NMe,2naphthoyl)(8),IAmp(9),Tyr(11)]-SRIF-NH(2) (27) in DMSO. Though the analogues have the sst(1) pharmacophore residues at the previously determined distances from each other, the positioning of the aromatic residues in 16, 23, and 27 is different from that described earlier, suggesting an induced fit mechanism for sst(1) binding of these novel, less constrained sst(1)-selective family members.

Novel receptor-targeted contrast agents for optical imaging of tumors

NASA Astrophysics Data System (ADS)

Becker, Andreas; Hessenius, Carsten; Bhargava, Sarah; Ebert, Bernd; Sukowski, Uwe; Rinneberg, Herbert H.; Wiedenmann, Bertram; Semmler, Wolfhard; Licha, Kai

2000-04-01

Many gastroenteropancreatic tumors express receptors for somatostatin (SST) and/or vasoactive intestinal peptide (VIP). These receptors can be used as molecular targets for the delivery of contrast agents for tumor diagnostics. We have synthesized conjugates consisting of a cyanine dye and an SST analogue or VIP for use as contrast agents in optical imaging. Receptor binding and internalization of these compounds were examined with optical methods in transfected RIN38 tumor cells expressing the SST2 receptor or a GFP- labeled VIP (VPAC1) receptor. Furthermore, biodistribution of the conjugates was examined by laser-induced fluorescence imaging in nude mice bearing SST2 or VPAC1 receptor- expressing tumors. After incubation of RIN38 SSTR2 cells in the presence of 100 nM indotricarbocyanine-SST analogue, cell-associated fluorescence increased, whereas no increase was observed when receptor-medicated endocytosis was inhibited. Indodicarbocyanine-VIP accumulated in RIN38 VPAC1 cells and co-localization with the GFP-labeled VPAC1 receptor was observed. After injection of indotricarbocyanine-SST analogue into tumor-bearing nude mice, SST2 receptor-positive tumors could be visualized for a time period from 10 min to at least 48 h. After application of indodicarbocyanine-VIP, a fluorescence signal in VIP1 receptor-expressing tumors was only detected during the first hour. We conclude that cyanine dye-labeled VIP and SST analogue are novel, targeted contrast agents for the optical imaging of tumors expressing the relevant receptor.

Superior Rhythm Discrimination With the SmartShock Technology Algorithm　- Results of the Implantable Defibrillator With Enhanced Features and Settings for Reduction of Inaccurate Detection (DEFENSE) Trial.

PubMed

Oginosawa, Yasushi; Kohno, Ritsuko; Honda, Toshihiro; Kikuchi, Kan; Nozoe, Masatsugu; Uchida, Takayuki; Minamiguchi, Hitoshi; Sonoda, Koichiro; Ogawa, Masahiro; Ideguchi, Takeshi; Kizaki, Yoshihisa; Nakamura, Toshihiro; Oba, Kageyuki; Higa, Satoshi; Yoshida, Keiki; Tsunoda, Soichi; Fujino, Yoshihisa; Abe, Haruhiko

2017-08-25

Shocks delivered by implanted anti-tachyarrhythmia devices, even when appropriate, lower the quality of life and survival. The new SmartShock Technology ® (SST) discrimination algorithm was developed to prevent the delivery of inappropriate shock. This prospective, multicenter, observational study compared the rate of inaccurate detection of ventricular tachyarrhythmia using the SST vs. a conventional discrimination algorithm.Methods and Results:Recipients of implantable cardioverter defibrillators (ICD) or cardiac resynchronization therapy defibrillators (CRT-D) equipped with the SST algorithm were enrolled and followed up every 6 months. The tachycardia detection rate was set at ≥150 beats/min with the SST algorithm. The primary endpoint was the time to first inaccurate detection of ventricular tachycardia (VT) with conventional vs. the SST discrimination algorithm, up to 2 years of follow-up. Between March 2012 and September 2013, 185 patients (mean age, 64.0±14.9 years; men, 74%; secondary prevention indication, 49.5%) were enrolled at 14 Japanese medical centers. Inaccurate detection was observed in 32 patients (17.6%) with the conventional, vs. in 19 patients (10.4%) with the SST algorithm. SST significantly lowered the rate of inaccurate detection by dual chamber devices (HR, 0.50; 95% CI: 0.263-0.950; P=0.034). Compared with previous algorithms, the SST discrimination algorithm significantly lowered the rate of inaccurate detection of VT in recipients of dual-chamber ICD or CRT-D.

The accuracy of SST retrievals from AATSR: An initial assessment through geophysical validation against in situ radiometers, buoys and other SST data sets

NASA Astrophysics Data System (ADS)

Corlett, G. K.; Barton, I. J.; Donlon, C. J.; Edwards, M. C.; Good, S. A.; Horrocks, L. A.; Llewellyn-Jones, D. T.; Merchant, C. J.; Minnett, P. J.; Nightingale, T. J.; Noyes, E. J.; O'Carroll, A. G.; Remedios, J. J.; Robinson, I. S.; Saunders, R. W.; Watts, J. G.

The Advanced Along-Track Scanning Radiometer (AATSR) was launched on Envisat in March 2002. The AATSR instrument is designed to retrieve precise and accurate global sea surface temperature (SST) that, combined with the large data set collected from its predecessors, ATSR and ATSR-2, will provide a long term record of SST data that is greater than 15 years. This record can be used for independent monitoring and detection of climate change. The AATSR validation programme has successfully completed its initial phase. The programme involves validation of the AATSR derived SST values using in situ radiometers, in situ buoys and global SST fields from other data sets. The results of the initial programme presented here will demonstrate that the AATSR instrument is currently close to meeting its scientific objectives of determining global SST to an accuracy of 0.3 K (one sigma). For night time data, the analysis gives a warm bias of between +0.04 K (0.28 K) for buoys to +0.06 K (0.20 K) for radiometers, with slightly higher errors observed for day time data, showing warm biases of between +0.02 (0.39 K) for buoys to +0.11 K (0.33 K) for radiometers. They show that the ATSR series of instruments continues to be the world leader in delivering accurate space-based observations of SST, which is a key climate parameter.

Soluble ST2 Plasma Concentrations Predict Mortality in HBV-Related Acute-on-Chronic Liver Failure

PubMed Central

Mo, Zhishuo; Zhu, Jianyun; Pang, Xiuqing; Wu, Zhebin; Wang, Ke; Li, Xinhua; Xie, Dongying; Gao, Zhiliang

2015-01-01

Hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) is a rapidly progressing and frequently fatal condition. The aim of this study was to determine whether interleukin- (IL-) 33 and soluble ST2 (sST2) were associated with disease severity and mortality in HBV-ACLF. We found that plasma levels of sST2 but not IL-33 were higher in HBV-ACLF patients compared with chronic hepatitis B (CHB) patients and healthy controls. However, plasma levels of IL-33, TNF-α, IFN-γ, and IL-10 did not correlate with sST2 levels. Similarly, immunohistochemistry revealed low IL-33 expression and high ST2 expression in liver sections of patients with HBV-ACLF. Evaluation of dynamic changes of sST2 in HBV-ACLF showed that plasma sST2 levels increased over time in patients who died during the 180-day follow-up but decreased in those who survived. In addition, plasma sST2 level after week 1 correlated with disease severity, as assessed by total bilirubin, prothrombin time, and model for end-stage liver disease score. Results of Kaplan-Meier survival analysis showed that higher sST2 concentration (≥87 ng/mL) at week 3 was associated with poor survival. These findings indicate the potential usefulness of sST2 as a predictor of disease severity and in making treatment decisions for patients with HBV-ACLF. PMID:25892854

Lagrangian Studies of Lateral Mixing

DTIC Science & Technology

2017-09-19

instabilities. A towed profiler was used to conduct synoptic, 4D surveys to resolve submesoscale variability. Results include finding that: (i...OBJECTIVES The LATMIX2 experimental program focused on two potential mechanisms for lateral mixing: 1. Submesoscale turbulence, generated by...Figure 1. LATMIX2 surveys . Red (black) lines mark Knorr (Atlantis) tracks plotted over SST images from 2 separate days, corresponding to the 2

Case Studies of Schools Receiving School Improvement Grants. Final Report. NCEE 2016-4002

ERIC Educational Resources Information Center

Le Floch, Kerstin Carlson; O'Day, Jennifer; Birman, Beatrice; Hurlburt, Steven; Nayfack, Michelle; Halloran, Clare; Boyle, Andrea; Brown, Seth; Mercado-Garcia, Diana; Goff, Rose; Rosenberg, Linda; Hulsey, Lara

2016-01-01

The Study of School Turnaround (SST) examines the change process in a diverse, purposive sample of schools receiving federal School Improvement Grants (SIG) from 2010-11 to 2012-13. With the passage of the American Recovery and Reinvestment Act of 2009 (ARRA), the SIG program underwent three major shifts. First, ARRA boosted total SIG funding in…

Potential predictability and actual skill of Boreal Summer Tropical SST and Indian summer monsoon rainfall in CFSv2-T382: Role of initial SST and teleconnections

NASA Astrophysics Data System (ADS)

Pillai, Prasanth A.; Rao, Suryachandra A.; Das, Renu S.; Salunke, Kiran; Dhakate, Ashish

2017-10-01

The present study assess the potential predictability of boreal summer (June through September, JJAS) tropical sea surface temperature (SST) and Indian summer monsoon rainfall (ISMR) using high resolution climate forecast system (CFSv2-T382) hindcasts. Potential predictability is computed using relative entropy (RE), which is the combined effect of signal strength and model spread, while the correlation between ensemble mean and observations represents the actual skill. Both actual and potential skills increase as lead time decreases for Niño3 index and equatorial East Indian Ocean (EEIO) SST anomaly and both the skills are close to each other for May IC hindcasts at zero lead. At the same time the actual skill of ISMR and El Niño Modoki index (EMI) are close to potential skill for Feb IC hindcasts (3 month lead). It is interesting to note that, both actual and potential skills are nearly equal, when RE has maximum contribution to individual year's prediction skill and its relationship with absolute error is insignificant or out of phase. The major contribution to potential predictability is from ensemble mean and the role of ensemble spread is limited for Pacific SST and ISMR hindcasts. RE values are able to capture the predictability contribution from both initial SST and simultaneous boundary forcing better than ensemble mean, resulting in higher potential skill compared to actual skill for all ICs. For Feb IC hindcasts at 3 month lead time, initial month SST (Feb SST) has important predictive component for El Niño Modoki and ISMR leading to higher value of actual skill which is close to potential skill. This study points out that even though the simultaneous relationship between ensemble mean ISMR and global SST is similar for all ICs, the predictive component from initial SST anomalies are captured well by Feb IC (3 month lead) hindcasts only. This resulted in better skill of ISMR for Feb IC (3 month lead) hindcasts compared to May IC (0 month lead) hindcasts. Lack of proper contribution from initial SST and teleconnections induces large absolute error for ISMR in May IC hindcasts resulting in very low actual skill. Thus the use of potential predictability skill and actual skill collectively help to understand the fidelity of the model for further improvement by differentiating the role of initial SST and simultaneous boundary forcing to some extent.

Finite cell lines of turkey sperm storage tubule cells: ultrastructure and protein analysis

USDA-ARS?s Scientific Manuscript database

Cell lines of turkey sperm storage tubule (SST) epithelial cells were established. Turkey SSTs were dissected from freshly obtained uterovaginal junction (UVJ) tissue and placed in explants culture on various substrates and media. Primary cultures of SST epithelium only survived and grew from SST ex...

NCEP SST Analysis

Science.gov Websites

Branches Global Climate & Weather Modeling Mesoscale Modeling Marine Modeling and Analysis Contact EMC , state and local government Web resources and services. Real-time, global, sea surface temperature (RTG_SST_HR) analysis For a regional map, click the desired area in the global SST analysis and anomaly maps

Self-System Therapy for Distress Associated with Persistent Low Back Pain: A Randomized Clinical Trial

PubMed Central

Waters, Sandra J.; McKee, Daphne C.; Campbell, Lisa C.; Shelby, Rebecca A.; Dixon, Kim E.; Fras, Anne Marie; Keefe, Francis J.

2015-01-01

Objective Persistent low back pain (PLBP) is associated with vulnerability to depression. PLBP frequently requires major changes in occupation and lifestyle, which can lead to a sense of failing to attain one’s personal goals (self-discrepancy). Method We conducted a clinical trial to examine the efficacy of self-system therapy (SST), a brief structured therapy for depression based on self-discrepancy theory. A total of 101 patients with PLBP and clinically significant depressive symptoms were randomized either to SST, pain education, or standard care. Results Patients receiving SST showed significantly greater improvement in depressive symptoms. Reduction in self-discrepancy predicted reduction in depressive symptoms only within the SST condition. Conclusions Findings support the utility of SST for individuals facing persistent pain and associated depression. PMID:26079438

Heat flux exchange estimation by using ATSR SST data in TOGA area

NASA Astrophysics Data System (ADS)

Xue, Yong; Lawrence, Sean P.; Llewellyn-Jones, David T.

1995-12-01

The study of phenomena such as ENSO requires consideration of the dynamics and thermodynamics of the coupled ocean-atmosphere system. The dynamic and thermal properties of the atmosphere and ocean are directly affected by air-sea transfers of fluxes of momentum, heat and moisture. In this paper, we present results of turbulent heat fluxes calculated by using two years (1992 and 1993) monthly average TOGA data and ATSR SST data in TOGA area. A comparison with published results indicates good qualitative agreement. Also, we compared the results of heat flux exchange by using ATSR SST data and by using the TOGA bucket SST data. The ATSR SST data set has been shown to be useful in helping to estimate the large space scale heat flux exchange.

Assimilation for skin SST in the NASA GEOS atmospheric data assimilation system.

PubMed

Akella, Santha; Todling, Ricardo; Suarez, Max

2017-01-01

The present article describes the sea surface temperature (SST) developments implemented in the Goddard Earth Observing System, Version 5 (GEOS-5) Atmospheric Data Assimilation System (ADAS). These are enhancements that contribute to the development of an atmosphere-ocean coupled data assimilation system using GEOS. In the current quasi-operational GEOS-ADAS, the SST is a boundary condition prescribed based on the OSTIA product, therefore SST and skin SST (Ts) are identical. This work modifies the GEOS-ADAS Ts by modeling and assimilating near sea surface sensitive satellite infrared (IR) observations. The atmosphere-ocean interface layer of the GEOS atmospheric general circulation model (AGCM) is updated to include near surface diurnal warming and cool-skin effects. The GEOS analysis system is also updated to directly assimilate SST-relevant Advanced Very High Resolution Radiometer (AVHRR) radiance observations. Data assimilation experiments designed to evaluate the Ts modification in GEOS-ADAS show improvements in the assimilation of radiance observations that extends beyond the thermal IR bands of AVHRR. In particular, many channels of hyperspectral sensors, such as those of the Atmospheric Infrared Sounder (AIRS), and Infrared Atmospheric Sounding Interferometer (IASI) are also better assimilated. We also obtained improved fit to withheld, in-situ buoy measurement of near-surface SST. Evaluation of forecast skill scores show marginal to neutral benefit from the modified Ts.

Development of MODIS data-based algorithm for retrieving sea surface temperature in coastal waters.

PubMed

Wang, Jiao; Deng, Zhiqiang

2017-06-01

A new algorithm was developed for retrieving sea surface temperature (SST) in coastal waters using satellite remote sensing data from Moderate Resolution Imaging Spectroradiometer (MODIS) aboard Aqua platform. The new SST algorithm was trained using the Artificial Neural Network (ANN) method and tested using 8 years of remote sensing data from MODIS Aqua sensor and in situ sensing data from the US coastal waters in Louisiana, Texas, Florida, California, and New Jersey. The ANN algorithm could be utilized to map SST in both deep offshore and particularly shallow nearshore waters at the high spatial resolution of 1 km, greatly expanding the coverage of remote sensing-based SST data from offshore waters to nearshore waters. Applications of the ANN algorithm require only the remotely sensed reflectance values from the two MODIS Aqua thermal bands 31 and 32 as input data. Application results indicated that the ANN algorithm was able to explaining 82-90% variations in observed SST in US coastal waters. While the algorithm is generally applicable to the retrieval of SST, it works best for nearshore waters where important coastal resources are located and existing algorithms are either not applicable or do not work well, making the new ANN-based SST algorithm unique and particularly useful to coastal resource management.

Somatostatin and Somatostatin Receptor Gene Expression in Dominant and Subordinate Males of an African Cichlid Fish

PubMed Central

Trainor, Brian C.; Hofmann, Hans A.

2009-01-01

Somatostatin is a neuropeptide best known for its inhibitory effects on growth hormone secretion and has recently been implicated in the control of social behavior. Several somatostatin receptor subtypes have been identified in vertebrates, but the functional basis for this diversity is still unclear. Here we investigate the expression levels of the somatostatin prepropeptide and two of its receptors, sstR2, and sstR3, in the brains of socially dominant and subordinate A. burtoni males using real-time PCR. Dominant males had higher somatostatin prepropeptide and sstR3 expression in hypothalamus compared to subordinate males. Hypothalamic sstR2 expression did not differ. There were no differences in gene expression in the telencephalon. We also observed an interesting difference between dominants and subordinates in the relationship between hypothalamic sstR2 expression and body size. As would be predicted based on the inhibitory effects of somatostatin on somatic growth, sstR2 expression was negatively correlated with body size in dominant males. In contrast sstR2 expression was positively correlated with body size in subordinate males. These results suggest that somatostatin prepropeptide and receptor gene expression in the hypothalamus are associated with the control of somatic growth in A. burtoni depending on social status. PMID:17374406

Assimilation for Skin SST in the NASA GEOS Atmospheric Data Assimilation System

NASA Technical Reports Server (NTRS)

Akella, Santha; Todling, Ricardo; Suarez, Max

2017-01-01

The present article describes the sea surface temperature (SST) developments implemented in the Goddard Earth Observing System, Version 5 (GEOS) Atmospheric Data Assimilation System (ADAS). These are enhancements that contribute to the development of an atmosphere-ocean coupled data assimilation system using GEOS. In the current quasi-operational GEOS-ADAS, the SST is a boundary condition prescribed based on the OSTIA product, therefore SST and skin SST (Ts) are identical. This work modifies the GEOS-ADAS Ts by modelling and assimilating near sea surface sensitive satellite infrared (IR) observations. The atmosphere-ocean interface layer of the GEOS atmospheric general circulation model (AGCM) is updated to include near-surface diurnal warming and cool-skin effects. The GEOS analysis system is also updated to directly assimilate SST-relevant Advanced Very High Resolution Radiometer (AVHRR) radiance observations. Data assimilation experiments designed to evaluate the Ts modification in GEOS-ADAS show improvements in the assimilation of radiance observations that extend beyond the thermal infrared bands of AVHRR. In particular, many channels of hyperspectral sensors, such as those of the Atmospheric Infrared Sounder (AIRS), and Infrared Atmospheric Sounding Interferometer (IASI) are also better assimilated. We also obtained improved fit to withheld insitu buoy measurement of near-surface SST. Evaluation of forecast skill scores show neutral to marginal benefit from the modified Ts.

Optogenetic and pharmacological evidence that somatostatin-GABA neurons are important regulators of parasympathetic outflow to the stomach.

PubMed

Lewin, Amanda E; Vicini, Stefano; Richardson, Janell; Dretchen, Kenneth L; Gillis, Richard A; Sahibzada, Niaz

2016-05-15

The dorsal motor nucleus of the vagus (DMV) in the brainstem consists primarily of vagal preganglionic neurons that innervate postganglionic neurons of the upper gastrointestinal tract. The activity of the vagal preganglionic neurons is predominantly regulated by GABAergic transmission in the DMV. The present findings indicate that the overwhelming GABAergic drive present at the DMV is primarily from somatostatin positive GABA (Sst-GABA) DMV neurons. Activation of both melanocortin and μ-opioid receptors at the DMV inhibits Sst-GABA DMV neurons. Sst-GABA DMV neurons may serve as integrative targets for modulating vagal output activity to the stomach. We have previously shown that local GABA signalling in the brainstem is an important determinant of vagally-mediated gastric activity. However, the neural identity of this GABA source is currently unknown. To determine this, we focused on the somatostatin positive GABA (Sst-GABA) interneuron in the dorsal motor nucleus of the vagus (DMV), a nucleus that is intimately involved in regulating gastric activity. Also of particular interest was the effect of melanocortin and μ-opioid agonists on neural activity of Sst-GABA DMV neurons because their in vivo administration in the DMV mimics GABA blockade in the nucleus. Experiments were conducted in brain slice preparation of transgenic adult Sst-IRES-Cre mice expressing tdTomato fluorescence, channelrhodopsin-2, archaerhodopsin or GCaMP3. Electrophysiological recordings were obtained from Sst-GABA DMV neurons or DiI labelled gastric-antrum projecting DMV neurons. Our results show that optogenetic stimulation of Sst-GABA neurons results in a robust inhibition of action potentials of labelled premotor DMV neurons to the gastric-antrum through an increase in inhibitory post-synaptic currents. The activity of the Sst-GABA neurons in the DMV is inhibited by both melanocortin and μ-opioid agonists. These agonists counteract the pronounced inhibitory effect of Sst-GABA neurons on vagal pre-motor neurons in the DMV that control gastric motility. These observations demonstrate that Sst-GABA neurons in the brainstem are crucial for regulating the activity of gastric output neurons in the DMV. Additionally, they suggest that these neurons serve as targets for converging CNS signals to regulate parasympathetic gastric function. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Evaluation of Enhanced High Resolution MODIS/AMSR-E SSTs and the Impact on Regional Weather Forecast

NASA Technical Reports Server (NTRS)

Schiferl, Luke D.; Fuell, Kevin K.; Case, Jonathan L.; Jedlovec, Gary J.

2010-01-01

Over the last few years, the NASA Short-term Prediction Research and Transition (SPoRT) Center has been generating a 1-km sea surface temperature (SST) composite derived from retrievals of the Moderate Resolution Imaging Spectroradiometer (MODIS) for use in operational diagnostics and regional model initialization. With the assumption that the day-to-day variation in the SST is nominal, individual MODIS passes aboard the Earth Observing System (EOS) Aqua and Terra satellites are used to create and update four composite SST products each day at 0400, 0700, 1600, and 1900 UTC, valid over the western Atlantic and Caribbean waters. A six month study from February to August 2007 over the marine areas surrounding southern Florida was conducted to compare the use of the MODIS SST composite versus the Real-Time Global SST analysis to initialize the Weather Research and Forecasting (WRF) model. Substantial changes in the forecast heat fluxes were seen at times in the marine boundary layer, but relatively little overall improvement was measured in the sensible weather elements. The limited improvement in the WRF model forecasts could be attributed to the diurnal changes in SST seen in the MODIS SST composites but not accounted for by the model. Furthermore, cloud contamination caused extended periods when individual passes of MODIS were unable to update the SSTs, leading to substantial SST latency and a cool bias during the early summer months. In order to alleviate the latency problems, the SPoRT Center recently enhanced its MODIS SST composite by incorporating information from the Advanced Microwave Scanning Radiometer-EOS (AMSR-E) instruments as well as the Operational Sea Surface Temperature and Sea Ice Analysis. These enhancements substantially decreased the latency due to cloud cover and improved the bias and correlation of the composites at available marine point observations. While these enhancements improved upon the modeled cold bias using the original MODIS SSTs, the discernable impacts on the WRF model were still somewhat limited. This paper explores several factors that may have contributed to this result. First, the original methodology to initialize the model used the most recent SST composite available in a hypothetical real ]time configuration, often matching the forecast initial time with an SST field that was 5-8 hours offset. To minimize the differences that result from the diurnal variations in SST, the previous day fs SST composite is incorporated at a time closest to the model initialization hour (e.g. 1600 UTC composite at 1500 UTC model initialization). Second, the diurnal change seen in the MODIS SST composites was not represented by the WRF model in previous simulations, since the SSTs were held constant throughout the model integration. To address this issue, we explore the use of a water skin-temperature diurnal cycle prediction capability within v3.1 of the WRF model to better represent fluctuations in marine surface forcing. Finally, the verification of the WRF model is limited to very few over-water sites, many of which are located near the coastlines. In order to measure the open ocean improvements from the AMSR-E, we could use an independent 2-dimensional, satellite-derived data set to validate the forecast model by applying an object-based verification method. Such a validation technique could aid in better understanding the benefits of the mesoscale SST spatial structure to regional models applications.

Solid-state dosimeters: A new approach for mammography measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brateman, Libby F., E-mail: bratel@radiology.ufl.edu; Heintz, Philip H.

2015-02-15

Purpose: To compare responses of modern commercially available solid-state dosimeters (SStDs) used in mammography medical physics surveys for two major vendors of current digital mammography units. To compare differences in dose estimates among SStD responses with ionization chamber (IC) measurements for several target/filter (TF) combinations and report their characteristics. To review scientific bases for measurements of quantities required for mammography for traditional measurement procedures and SStDs. Methods: SStDs designed for use with modern digital mammography units were acquired for evaluation from four manufacturers. Each instrument was evaluated under similar conditions with the available mammography beams provided by two modern full-fieldmore » digital mammography units in clinical use: a GE Healthcare Senographe Essential (Essential) and a Hologic Selenia Dimensions 5000 (Dimensions), with TFs of Mo/Mo, Mo/Rh; and Rh/Rh and W/Rh, W/Ag, and W/Al, respectively. Measurements were compared among the instruments for the TFs over their respective clinical ranges of peak tube potentials for kVp and half-value layer (HVL) measurements. Comparisons for air kerma (AK) and their associated relative calculated average glandular doses (AGDs), i.e., using fixed mAs, were evaluated over the limited range of 28–30 kVp. Measurements were compared with reference IC measurements for AK, reference HVLs and calculated AGD, for two compression paddle heights for AK, to evaluate scatter effects from compression paddles. SStDs may require different positioning from current mammography measurement protocols. Results: Measurements of kVp were accurate in general for the SStDs (within −1.2 and +1.1 kVp) for all instruments over a wide range of set kVp’s and TFs and most accurate for Mo/Mo and W/Rh. Discrepancies between measurements and reference values were greater for HVL and AK. Measured HVL values differed from reference values by −6.5% to +3.5% depending on the SStD and TF. AK measurements over limited (28–30) kVp’s ranged from −6% to +7% for SStDs, compared with IC reference values. Relative AGDs for each SStD using its associated measurements of kVp, HVL and AK underestimated AGD in nearly all cases, compared with reference IC values, with discrepancies of <−1% to ∼−10%. Some differences in AGD were related to differences in contributions of compression paddle scatter to AK measurements made by ICs. Applying measured factors for scatter effects in AK measurements for three SStDs reduced discrepancies between −6.2% and +1.3%, shifting AGDs from SStDs closer to IC AGDs. Conclusions: This study revealed that SStD measurements yielded good agreement with set kVp, poor agreement with standard HVL determinations, and AK measurements that were substantially different from IC measurements. Discrepancies are partly related to the scattered radiation measured by ICs in determining AK. As a result, IC measurements required for AGD, using currently accepted methodology, typically result in higher AGDs than SStDs, because current methodologies do not account for differing instrument responses to scatter. HVLs reported by SStDs contribute to discrepancies in calculated AGD that depend on kVp and TF. Medical physicists are encouraged to compare their results for SStD instruments using a similar methodology for potential discrepancies with their traditional instruments.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xue, Yongkang; De Sales, Fernando; Lau, William K. -M.

The Sahel climate system had experienced one of the strongest interdecadal climate variabilities and the longest drought on the planet in the twentieth century. Most modeling studies on the decadal variability of the Sahel climate so far have focused on the role of anomalies in either sea surface temperature (SST), land surface processes, or aerosols concentration. The Second West African Monsoon Modeling and Evaluation Project Experiment (WAMME II) is designed to improve understanding of the possible roles and feedback of SST, land use land cover change (LULCC), and aerosols forcings in the Sahel climate system at seasonal to decadal scales.more » The WAMME II strategy is to apply observationally based anomaly forcing, i.e., “idealized but realistic” forcing, in simulations by general circulation models’ (GCMs) and regional climate models’ (RCMs) to test the relative impacts of such forcings in producing/amplifying the Sahelian seasonal and decadal climate variability, including the 20th century drought. To test individual ocean’s SST effect, a special approach in the experimental design is taken to avoid undermine its effect. This is the first multi-model experiment specifically designed to simultaneously evaluate relative contributions of multiple-external forcings to the Sahel drought. This paper presents the major results and preliminary findings of the WAMME II SST experiment, including each ocean’s contribution to the global SST effect, as well as comparison of the SST effect with the LULCC effect. The common empirical orthogonal functions and other analyses are applied to assess and comprehend the discrepancies among the models. In general, the WAMME II models have reached a consensus on SST’s major contribution to the great Sahel drought and show that with the maximum possible SST forcing, it can produce up to 60% of the absolute amount of precipitation difference between the 1980s and the 1950s. This paper has 3 also delineated the role of SSTs in triggering and maintaining the Sahel drought, suggesting a potential predictability of WAM development linked to SST. Among different ocean basins, the Pacific and Indian Ocean SSTs have the greatest impact on the 1980s drought. The WAMME II, however, fails to reach a consensus on the role of the Mediterranean Sea SST. The changes in circulation, moisture flux convergence, and associated surface energy balances are the main mechanisms for the SST effect. The paper also compares the SST effect with the LULCC effects. It is shown that the prescribed land forcing produces about 40% of the precipitation difference between the 1980s and the 1950s, which is less than SST contribution but still of first order in the Sahel climate system. The role of land surface processes in responding to and amplifying the drought has also been identified. The results demonstrate that catastrophic consequences likely occur in the regional climate when SST anomalies in individual ocean basins and in land conditions combine synergistically to favor drought. Due to limited ensemble members, aerosol effects are not compared. Since the SST and land forcing in the real world are likely smaller than specified in this study, further investigations on the effects of aerosols as well as of other external forcings, such as greenhouse gases, and of atmospheric internal variability, are necessary. Moreover, although the WAMEE II models support a general consensus on SST and LULCC effects, there are still large discrepancies in how these models produce the Sahel drought in the 1980s. Better atmospheric observational and analysis data including more processes and components are necessary to validate and constrain models, and to guide further model development and improvement.« less

Decadal variability of the Tropical Atlantic Ocean Surface Temperature in shipboard measurements and in a Global Ocean-Atmosphere model

NASA Technical Reports Server (NTRS)

Mehta, Vikram M.; Delworth, Thomas

1995-01-01

Sea surface temperature (SST) variability was investigated in a 200-yr integration of a global model of the coupled oceanic and atmospheric general circulations developed at the Geophysical Fluid Dynamics Laboratory (GFDL). The second 100 yr of SST in the coupled model's tropical Atlantic region were analyzed with a variety of techniques. Analyses of SST time series, averaged over approximately the same subregions as the Global Ocean Surface Temperature Atlas (GOSTA) time series, showed that the GFDL SST anomalies also undergo pronounced quasi-oscillatory decadal and multidecadal variability but at somewhat shorter timescales than the GOSTA SST anomalies. Further analyses of the horizontal structures of the decadal timescale variability in the GFDL coupled model showed the existence of two types of variability in general agreement with results of the GOSTA SST time series analyses. One type, characterized by timescales between 8 and 11 yr, has high spatial coherence within each hemisphere but not between the two hemispheres of the tropical Atlantic. A second type, characterized by timescales between 12 and 20 yr, has high spatial coherence between the two hemispheres. The second type of variability is considerably weaker than the first. As in the GOSTA time series, the multidecadal variability in the GFDL SST time series has approximately opposite phases between the tropical North and South Atlantic Oceans. Empirical orthogonal function analyses of the tropical Atlantic SST anomalies revealed a north-south bipolar pattern as the dominant pattern of decadal variability. It is suggested that the bipolar pattern can be interpreted as decadal variability of the interhemispheric gradient of SST anomalies. The decadal and multidecadal timescale variability of the tropical Atlantic SST, both in the actual and in the GFDL model, stands out significantly above the background 'red noise' and is coherent within each of the time series, suggesting that specific sets of processes may be responsible for the choice of the decadal and multidecadal timescales. Finally, it must be emphasized that the GFDL coupled ocean-atmosphere model generates the decadal and multidecadal timescale variability without any externally applied force, solar or lunar, at those timescales.

A randomized controlled study of a social skills training for preadolescent children with autism spectrum disorders: generalization of skills by training parents and teachers?

PubMed Central

2014-01-01

Background Social skills training (SST) is a common intervention for children with autism spectrum disorders (ASDs) to improve their social and communication skills. Despite the fact that SSTs are often applied in clinical practice, the evidence for the effectiveness of these trainings for children with ASD is inconclusive. Moreover, long term outcome and generalization of learned skills are little evaluated. Additionally, there is no research on the influence of involvement of parents and teachers on effectiveness of SST and on the generalization of learned social skills to daily life. We expect parent and teacher involvement in SST to enhance treatment efficacy and to facilitate generalization of learned skills to daily life. Method/Design In a randomized controlled trial (RCT) with three conditions, 120 participants with ASD at the end of primary school (10–12 years of calendar age) have been randomized to SST, SST-PTI (SST with Parent & Teacher Involvement), or care-as-usual. The SST consists of 18 group sessions of 1.5 hours for the children. In the SST-PTI condition, parents additionally participate in 8 parent sessions and parents and teachers are actively involved in homework assignments. Assessment takes place at three moments: before and immediately after the intervention period and at 6 months follow-up. Primary outcome is socialization, as an aspect of adaptive functioning. Secondary outcomes focus on specific social skills children learn during SST and on more general social skills pertaining to home and community settings from a multi-informant perspective. Additionally, possible predictors of treatment outcome will be assessed. Discussion The current study is an RCT study evaluating SST in a large sample of Dutch children with ASD in a specific age range (10–12 years). Strengths of the study are the use of one manualized protocol, application of standardized and internationally used rating instruments, use of multiple raters, investigation of generalization of learned skills to daily life, and the evaluation of efficacy in the longer term by follow-up measures at 6 months after the end of training. Trial registration NTR2405 PMID:24989854

Immediate effects of different schedules of somatostatin on portal pressure in patients with liver cirrhosis.

PubMed

Zhang, C; Xu, J-M; Kong, D-R; Min, X-K; Chen, R

2013-06-01

Somatostatin (SST) is used for the treatment of acute variceal bleeding based on its ability to decrease portal pressure and collateral blood flow. To date, no studies have focused on the immediate-early effects (between 1 and 30 min) of SST. The aim of this study was to compare the efficacy of different schedules of SST therapy with placebo on portal pressure in patients with portal hypertension treated with portal-azygous disconnection and to test whether an increase in bolus or infusion dose can improve the clinical efficacy of SST therapy.   Patients were treated with four different schedules: (a) standard dose (n = 11): one 250 μg bolus + a continuous infusion of 250 μg/h; (b) medium dose (n = 10): 500 μg bolus + a continuous infusion of 250 μg/h; (c) high dose (n = 10): 250 μg bolus + a continuous infusion of 500 μg/h; (d) control (n = 10): an injection of placebo (saline) followed by a placebo infusion. Following SST or placebo administration, portal pressure, central venous pressure (CVP), systemic blood pressure and heart rate (HR) were measured at 1, 3, 5, 7, 10 and 30 min.   The three schedules of SST induced a marked, rapid and highly significant decrease in portal pressure. The decline in portal pressure was moderate at 1 min (P < 0·040), achieved a peak effect at 5 min (P < 0·009) and remained decreased at 30 min. The effect of SST on portal pressure was significantly greater than placebo from 1 min after administration. There were no significant differences in portal pressure decrease between the three schedules of SST. The three schedules of SST and the placebo schedule did not induce significant changes in HR, systemic blood pressure and CVP.   This study shows that SST is effective in decreasing portal pressure within 30 min of administration in patients with liver cirrhosis. The clinical schedule used in this study was reasonable and safe. © 2013 Blackwell Publishing Ltd.

Homologous upregulation of sst2 somatostatin receptor expression in the rat arcuate nucleus in vivo.

PubMed

Tannenbaum, G S; Turner, J; Guo, F; Videau, C; Epelbaum, J; Beaudet, A

2001-07-01

In vitro studies using various cell systems have provided conflicting results regarding homologous regulation of somatostatin (SRIH) receptors, and information on whether SRIH regulates the expression of its own receptors in vivo is lacking. In the present study we examined, by in situ hybridization, the effects of pretreatment with the sst2-preferring SRIH analog, octreotide, in vivo, on mRNA levels of two SRIH receptor subtypes, sst1 and sst2, in rat brain and pituitary. (125)I-[DTrp(8)]-SRIH binding was also measured in these regions. Three hours after the iv injection of 50 microg octreotide to conscious adult male rats, there was a 46% increase (p < 0.01) in the labeling density of sst2 mRNA-expressing cells in the hypothalamic arcuate nucleus compared to normal saline-pretreated controls, but not in any of the other brain regions examined. Computer-assisted image analysis revealed that 3 h exposure to octreotide significantly (p < 0.01) augmented both the number and labeling density of sst2 mRNA-expressing cells in the arcuate nucleus, compared to those in saline-treated controls. By contrast, within the anterior pituitary gland, in vivo exposure to octreotide did not affect the expression of sst2 mRNA. No changes in sst1 mRNA-expressing cells were observed after octreotide treatment in any of the regions measured, indicating that the observed effects were homologous, i.e. specific of the receptor subtype stimulated. Octreotide pretreatment was also without effect on the density of (125)I-[DTrp(8)]-SRIH binding in either the arcuate nucleus or pituitary. These results demonstrate, for the first time, that SRIH preexposure in vivo upregulates the expression of a subtype of its own receptors, sst2, within the central nervous system. They further suggest that pretreatment with SRIH in vivo does not cause sst2 receptor desensitization in arcuate nucleus and pituitary. Such homologous regulatory mechanisms may play an important role in the neuroendocrine control of growth hormone (GH) secretion by the arcuate nucleus. Copyright 2001 S. Karger AG, Basel

Analysis of Ultra High Resolution Sea Surface Temperature Level 4 Datasets

NASA Technical Reports Server (NTRS)

Wagner, Grant

2011-01-01

Sea surface temperature (SST) studies are often focused on improving accuracy, or understanding and quantifying uncertainties in the measurement, as SST is a leading indicator of climate change and represents the longest time series of any ocean variable observed from space. Over the past several decades SST has been studied with the use of satellite data. This allows a larger area to be studied with much more frequent measurements being taken than direct measurements collected aboard ship or buoys. The Group for High Resolution Sea Surface Temperature (GHRSST) is an international project that distributes satellite derived sea surface temperatures (SST) data from multiple platforms and sensors. The goal of the project is to distribute these SSTs for operational uses such as ocean model assimilation and decision support applications, as well as support fundamental SST research and climate studies. Examples of near real time applications include hurricane and fisheries studies and numerical weather forecasting. The JPL group has produced a new 1 km daily global Level 4 SST product, the Multiscale Ultrahigh Resolution (MUR), that blends SST data from 3 distinct NASA radiometers: the Moderate Resolution Imaging Spectroradiometer (MODIS), the Advanced Very High Resolution Radiometer (AVHRR), and the Advanced Microwave Scanning Radiometer ? Earth Observing System(AMSRE). This new product requires further validation and accuracy assessment, especially in coastal regions.We examined the accuracy of the new MUR SST product by comparing the high resolution version and a lower resolution version that has been smoothed to 19 km (but still gridded to 1 km). Both versions were compared to the same data set of in situ buoy temperature measurements with a focus on study regions of the oceans surrounding North and Central America as well as two smaller regions around the Gulf Stream and California coast. Ocean fronts exhibit high temperature gradients (Roden, 1976), and thus satellite data of SST can be used in the detection of these fronts. In this case, accuracy is less of a concern because the primary focus is on the spatial derivative of SST. We calculated the gradients for both versions of the MUR data set and did statistical comparisons focusing on the same regions.

A randomized controlled study of a social skills training for preadolescent children with autism spectrum disorders: generalization of skills by training parents and teachers?

PubMed

Dekker, Vera; Nauta, Maaike H; Mulder, Erik J; Timmerman, Marieke E; de Bildt, Annelies

2014-07-02

Social skills training (SST) is a common intervention for children with autism spectrum disorders (ASDs) to improve their social and communication skills. Despite the fact that SSTs are often applied in clinical practice, the evidence for the effectiveness of these trainings for children with ASD is inconclusive. Moreover, long term outcome and generalization of learned skills are little evaluated. Additionally, there is no research on the influence of involvement of parents and teachers on effectiveness of SST and on the generalization of learned social skills to daily life. We expect parent and teacher involvement in SST to enhance treatment efficacy and to facilitate generalization of learned skills to daily life. In a randomized controlled trial (RCT) with three conditions, 120 participants with ASD at the end of primary school (10-12 years of calendar age) have been randomized to SST, SST-PTI (SST with Parent & Teacher Involvement), or care-as-usual. The SST consists of 18 group sessions of 1.5 hours for the children. In the SST-PTI condition, parents additionally participate in 8 parent sessions and parents and teachers are actively involved in homework assignments. Assessment takes place at three moments: before and immediately after the intervention period and at 6 months follow-up. Primary outcome is socialization, as an aspect of adaptive functioning. Secondary outcomes focus on specific social skills children learn during SST and on more general social skills pertaining to home and community settings from a multi-informant perspective. Additionally, possible predictors of treatment outcome will be assessed. The current study is an RCT study evaluating SST in a large sample of Dutch children with ASD in a specific age range (10-12 years). Strengths of the study are the use of one manualized protocol, application of standardized and internationally used rating instruments, use of multiple raters, investigation of generalization of learned skills to daily life, and the evaluation of efficacy in the longer term by follow-up measures at 6 months after the end of training. NTR2405.

An Assessment of the Subseasonal Forecast Performance in the Extended Global Ensemble Forecast System (GEFS)

NASA Astrophysics Data System (ADS)

Sinsky, E.; Zhu, Y.; Li, W.; Guan, H.; Melhauser, C.

2017-12-01

Optimal forecast quality is crucial for the preservation of life and property. Improving monthly forecast performance over both the tropics and extra-tropics requires attention to various physical aspects such as the representation of the underlying SST, model physics and the representation of the model physics uncertainty for an ensemble forecast system. This work focuses on the impact of stochastic physics, SST and the convection scheme on forecast performance for the sub-seasonal scale over the tropics and extra-tropics with emphasis on the Madden-Julian Oscillation (MJO). A 2-year period is evaluated using the National Centers for Environmental Prediction (NCEP) Global Ensemble Forecast System (GEFS). Three experiments with different configurations than the operational GEFS were performed to illustrate the impact of the stochastic physics, SST and convection scheme. These experiments are compared against a control experiment (CTL) which consists of the operational GEFS but its integration is extended from 16 to 35 days. The three configurations are: 1) SPs, which uses a Stochastically Perturbed Physics Tendencies (SPPT), Stochastic Perturbed Humidity (SHUM) and Stochastic Kinetic Energy Backscatter (SKEB); 2) SPs+SST_bc, which uses a combination of SPs and a bias-corrected forecast SST from the NCEP Climate Forecast System Version 2 (CFSv2); and 3) SPs+SST_bc+SA_CV, which combines SPs, a bias-corrected forecast SST and a scale aware convection scheme. When comparing to the CTL experiment, SPs shows substantial improvement. The MJO skill has improved by about 4 lead days during the 2-year period. Improvement is also seen over the extra-tropics due to the updated stochastic physics, where there is a 3.1% and a 4.2% improvement during weeks 3 and 4 over the northern hemisphere and southern hemisphere, respectively. Improvement is also seen when the bias-corrected CFSv2 SST is combined with SPs. Additionally, forecast performance enhances when the scale aware convection scheme (SPs+SST_bc+SA_CV) is added, especially over the tropics. Among the three experiments, the SPs+SST_bc+SA_CV is the best configuration in MJO forecast skill.

A comparison of arrow, trapezoidal and M wing concepts using a Mach 2 supersonic cruise transport mission

NASA Technical Reports Server (NTRS)

Martin, Glenn L.; Tice, David C.; Marcum, Don C., Jr.; Seidel, Jonathan A.

1991-01-01

The present analytic study of the potential performance of SST configurations radically differing from arrow-winged designs in lifting surface planform geometry gives attention to trapezoidal-wing and M-wing configurations; the trapezoidal wing is used as the baseline in the performance comparisons. The design mission was all-supersonic (Mach 2), carrying 248 passengers over a 5500 nautical-mile range. Design constraints encompassed approach speed, TO&L field length, and engine-out second-segment climb and missed-approach performance. Techniques for improving these configurations are discussed.

On the role of Sea Surface Temperature forcing in the numerical simulation of a Tropical-Like Cyclone event in the Mediterranean Sea

NASA Astrophysics Data System (ADS)

Ricchi, Antonio; Marcello Miglietta, Mario; Barbariol, Francesco; Benetazzo, Alvise; Bonaldo, Davide; Falcieri, Francesco M.; Russo, Aniello; Sclavo, Mauro; Carniel, Sandro

2017-04-01

Between 19-22 January 2014 a baroclinic wave from the Atlantic region goes in cutoff over the Strait of Gibraltar. The resulting depression remains active for approximately 80 hours, passing off shore of the north African coast, crossing the Tyrrhenian Sea and the Adriatic Sea, before turning south. During the first phase (close to the Balearic islands) and when passing over the Adriatic, the depression assumes the characteristics of a TLC (Tropical Like Cyclones). Sea Surface Temperature (SST) is a very important factor for a proper numerical simulation of these events hence we chose to model this TLC event using the COAWST suite (Coupled Ocean Atmosphere Wave Sediment Transport Modelling System). In the first phase of our work we identified the best model configuration to reproduce the phenomenon, extensively testing different microphysics and PBL (Planetary Boundary Layer) schemes available in the numerical model WRF (Weather Research for Forecasting). In the second phase, in order to evaluate the impact of SST, we used the best physical set-up that reproduces the phenomenon in terms of intensity, trajectory and timing, using four different methods of implementation of the SST in the model: i)from a spectrum-radiometer at 8.3 km resolution and updated every six hours; ii) from a dataset provided by "MyOcean" at 1 km resolution and updated every 6 hours; iii) from COAWST suite run in coupled atmosphere-ocean configuration; iv) from COAWST suite in fully coupled atmosphere-ocean- wave configuration). Results show the importance of the selected microphysics scheme in order to correctly reproduce the TLC trajectory, and of the use of high-resolution and high-frequency SST fields, updated every hour in order to reproduce the diurnal cycles. Coupled numerical runs produce less intense heat fluxes which on turn result in better TLC trajectories, more realistic timing and intensity when compared with standalone simulations, even if the latter use a high resolution SST. Last, a temporary increase of the mixed layer depth along the trajectory of the TLC was exhibited by the fully coupled run during the two phases of maximum intensity of the phenomenon, when the wave field is more developed and acts more intensely on the vertical mixing. We will discuss how these results can be improved or further validated in proximity of land by using satellite information that will be available within the framework of H2020 CEASELESS project.

Projected SST trends across the Caribbean Sea based on PRECIS downscaling of ECHAM4, under the SRES A2 and B2 scenarios

NASA Astrophysics Data System (ADS)

Nurse, Leonard A.; Charlery, John L.

2016-01-01

The Caribbean Sea and adjacent land areas are highly sensitive to the projected impacts of global climate change. The countries bordering the Caribbean Sea depend heavily on coastal and marine assets as a major source of livelihood support. Rising sea surface temperatures (SSTs) are known to be associated with coral bleaching, ocean acidification, and other phenomena that threaten livelihoods in the region. The paucity of SST systematic observations in both the Caribbean Sea and adjoining Western Atlantic waters is a limiting factor in the projection of future climate change impacts on the region's marine resources. Remote sensing of SST by satellites began only within the last three decades and although the data collected so far might be insufficient to provide conclusive definitions of long-term SST variations in the Caribbean waters, these data along with the output from climate model simulations provide a useful basis for gaining further insights into plausible SST futures under IPCC SRES scenarios. In this paper, we examine the recent SST records from the NESDIS AVHRR satellite data and NOAA Optimum Interpolation (OI) sea surface temperature V2 and provide a comparative analysis of projected SST changes for the Caribbean Sea up to the end of the twenty-first century, under the SRES A2 and B2 scenarios' simulations of the sea surface skin temperatures (SSsT) using the Hadley Centre's regional model, PRECIS. The implications of these projected SST changes for bleaching of coral reefs, one of the region's most valuable marine resource, and for rainfall are also discussed.

Monitoring and trend mapping of sea surface temperature (SST) from MODIS data: a case study of Mumbai coast.

PubMed

Azmi, Samee; Agarwadkar, Yogesh; Bhattacharya, Mohor; Apte, Mugdha; Inamdar, Arun B

2015-04-01

Sea surface temperature (SST) is one of the most important parameters in monitoring ecosystem health in the marine and coastal environment. Coastal ecosystem is largely dependent on ambient temperature and temperature fronts for marine/coastal habitat and its sustainability. Hence, thermal pollution is seen as a severe threat for ecological health of coastal waters across the world. Mumbai is one of the largest metropolises of the world and faces severe domestic and industrial effluent disposal problem, of which thermal pollution is a major issue with policy-makers and environmental stakeholders. This study attempts to understand the long-term SST variation in the coastal waters off Mumbai, on the western coast of India, and to identify thermal pollution zones. Analysis of SST trends in the near-coastal waters for the pre- and post-monsoon seasons from the year 2004 to the year 2010 has been carried out using Moderate Resolution Imaging Spectro-radiometer (MODIS) Thermal Infra-red (TIR) bands. SST is calculated with the help of bands 31 and 32 using split window method. Several statistical operations were then applied to find the seasonal averages in SST and the standard deviation of SST in the study area. Maximum variation in SST was found within a perpendicular distance of 5 km from the shoreline during the study period. Also, a warm water mass was found to form consistently off coast during the winter months. Several anthropogenic sources of thermal pollution could be identified which were found to impact various locations along the coast.

Effects of southeastern Pacific sea surface temperature on the double-ITCZ bias in NCAR CESM1

NASA Astrophysics Data System (ADS)

Song, F.; Zhang, G. J.

2016-12-01

The double-intertropical convergence zone (ITCZ) is a long-standing bias in the coupled general circulation models (CGCMs). The warm biases in southeastern Pacific (SEP) sea surface temperature (SST) are also evident in many CGCMs. In this study, the role of SEP SST in the double-ITCZ is investigated by prescribing the observed SEP SST in the Community Earth System Model version 1 (CESM1). Both the double-ITCZ and dry equator problems are significantly improved with SEP SST prescribed. The colder SST over the SEP increases the southeasterly winds extending outside the prescribed SST region, cooling the ocean there via increased evaporation. The enhanced descending motion over the SEP strengthens the Walker circulation, so the low-level wind convergence in the tropical western Pacific is increased. The reduced wind speed leads to warmer SST and stronger convection there. The stronger convection in turn leads to more cloud and reduces the incoming solar radiation, cooling the SST. These competing effects between radiative heat flux and latent heat flux make the atmospheric heat flux secondary to the ocean dynamics in the western Pacific warming. The increased easterly winds over the equatorial Pacific enhance upwelling and shoal the thermocline over the eastern Pacific. This Bjerknes feedback plays an important role in the improvement of dry equator. The changes of surface wind and wind curl also lead to weaker South Equatorial Countercurrent and stronger South Equatorial Current, preventing the warm water from expanding eastward, thereby improving both the double-ITCZ and dry equator.

Pasireotide and octreotide antiproliferative effects and sst2 trafficking in human pancreatic neuroendocrine tumor cultures.

PubMed

Mohamed, Amira; Blanchard, Marie-Pierre; Albertelli, Manuela; Barbieri, Federica; Brue, Thierry; Niccoli, Patricia; Delpero, Jean-Robert; Monges, Genevieve; Garcia, Stephane; Ferone, Diego; Florio, Tullio; Enjalbert, Alain; Moutardier, Vincent; Schonbrunn, Agnes; Gerard, Corinne; Barlier, Anne; Saveanu, Alexandru

2014-10-01

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) raise difficult therapeutic problems despite the emergence of targeted therapies. Somatostatin analogs (SSA) remain pivotal therapeutic drugs. However, the tachyphylaxis and the limited antitumoral effects observed with the classical somatostatin 2 (sst2) agonists (octreotide and lanreotide) led to the development of new SSA, such as the pan sst receptor agonist pasireotide. Our aim was to compare the effects of pasireotide and octreotide on cell survival, chromogranin A (CgA) secretion, and sst2 phosphorylation/trafficking in pancreatic NET (pNET) primary cells from 15 tumors. We established and characterized the primary cultures of human pancreatic tumors (pNETs) as powerful preclinical models for understanding the biological effects of SSA. At clinically relevant concentrations (1-10 nM), pasireotide was at least as efficient as octreotide in inhibiting CgA secretion and cell viability through caspase-dependent apoptosis during short treatments, irrespective of the expression levels of the different sst receptors or the WHO grade of the parental tumor. Interestingly, unlike octreotide, which induces a rapid and persistent partial internalization of sst2 associated with its phosphorylation on Ser341/343, pasireotide did not phosphorylate sst2 and induced a rapid and transient internalization of the receptor followed by a persistent recycling at the cell surface. These results provide the first evidence, to our knowledge, of striking differences in the dynamics of sst2 trafficking in pNET cells treated with the two SSAs, but with similar efficiency in the control of CgA secretion and cell viability. © 2014 Society for Endocrinology.

Serum soluble ST2 as diagnostic marker of systemic inflammatory reactive syndrome of bacterial etiology in children.

PubMed

Calò Carducci, Francesca Ippolita; Aufiero, Lelia Rotondi; Folgori, Laura; Vittucci, Anna Chiara; Amodio, Donato; De Luca, Maia; Li Pira, Giuseppina; Bergamini, Alberto; Pontrelli, Giuseppe; Finocchi, Andrea; D'Argenio, Patrizia

2014-02-01

Accurate and timely diagnosis of community-acquired bacterial versus viral infections in children with systemic inflammatory response syndrome (SIRS) remains challenging both for clinician and laboratory. In the quest of new biochemical markers to distinguish bacterial from viral infection, we have explored the possible role of the soluble secreted form of ST2 (sST2). This explorative prospective cohort study included children with SIRS who were suspected of having community-acquired infections. Plasma samples for sST2 measurement were obtained from 64 hospitalized children, 41 of whom had SIRS of bacterial etiology and 23 SIRS of viral etiology, and from 20 healthy, age- and sex-matched control children. sST2 measurement was carried out by enzyme-linked immunosorbent assay in parallel with standard measurements of procalcitonin (PCT) and C reactive protein (CRP). Our findings demonstrate that children with SIRS associated with bacterial infection present significantly increased levels of sST2, when compared with patients with SIRS of viral etiology and healthy children. More important, receiver operating characteristic curve analysis indicated that sST2 has a significant diagnostic performance with respect to early identification of SIRS of bacterial etiology, which was similar to that of PCT and greater than that of CRP. Finally, the combination of sST2 plus PCT and/or CRP, and PCT plus CRP increased their sensitivity and negative predictive value compared with sST2, PCT and CRP alone. In conclusion, sST2 level may prove useful in predicting bacterial etiology in children with SIRS.

Stratospheric role in interdecadal changes of El Niño impacts over Europe

NASA Astrophysics Data System (ADS)

Ayarzagüena, B.; López-Parages, J.; Iza, M.; Calvo, N.; Rodríguez-Fonseca, B.

2018-04-01

The European precipitation response to El Niño (EN) has been found to present interdecadal changes, with alternated periods of important or negligible EN impact in late winter. These periods are associated with opposite phases of multi-decadal sea surface temperature (SST) variability, which modifies the tropospheric background and EN teleconnections. In addition, other studies have shown how SST anomalies in the equatorial Pacific, and in particular, the location of the largest anomalous SST, modulate the stratospheric response to EN. Nevertheless, the role of the stratosphere on the stationarity of EN response has not been investigated in detail so far. Using reanalysis data, we present a comprehensive study of EN teleconnections to Europe including the role of the ocean background and the stratosphere in the stationarity of the signal. The results reveal multidecadal variability in the location of EN-related SST anomalies that determines different teleconnections. In periods with relevant precipitation signal over Europe, the EN SST pattern resembles Eastern Pacific EN and the stratospheric pathway plays a key role in transmitting the signal to Europe in February, together with two tropospheric wavetrains that transmit the signal in February and April. Conversely, the stratospheric pathway is not detected in periods with a weak EN impact on European precipitation, corresponding to EN-related SST anomalies primarily located over the central Pacific. SST mean state and its associated atmospheric background control the location of EN-related SST anomalies in different periods and modulate the establishment of the aforementioned stratospheric pathway of EN teleconnection to Europe too.

Influence of secondary settling tank performance on suspended solids mass balance in activated sludge systems.

PubMed

Patziger, M; Kainz, H; Hunze, M; Józsa, J

2012-05-01

Secondary settling is the final step of the activated sludge-based biological waste water treatment. Secondary settling tanks (SSTs) are therefore an essential unit of producing a clear effluent. A further important function of SSTs is the sufficient thickening to achieve highly concentrated return sludge and biomass within the biological reactor. In addition, the storage of activated sludge is also needed in case of peak flow events (Ekama et al., 1997). Due to the importance of a high SST performance the problem has long been investigated (Larsen, 1977; Krebs, 1991; Takács et al., 1991; Ekama et al., 1997; Freimann, 1999; Patziger et al., 2005; Bürger et al., 2011), however, a lot of questions are still to solve regarding e.g. the geometrical features (inflow, outflow) and operations (return sludge control, scraper mechanism, allowable maximum values of surface overflow rates). In our study we focused on SSTs under dynamic load considering both the overall unsteady behaviour and the features around the peaks, investigating the effect of various sludge return strategies as well as the inlet geometry on SST performance. The main research tool was a FLUENT-based novel mass transport model consisting of two modules, a 2D axisymmetric SST model and a mixed reactor model of the biological reactor (BR). The model was calibrated and verified against detailed measurements of flow and concentration patterns, sludge settling, accompanied with continuous on-line measurement of in- and outflow as well as returned flow rates of total suspended solids (TSS) and water. As to the inlet arrangement a reasonable modification of the geometry could result in the suppression of the large scale flow structures of the sludge-water interface thus providing a significant improvement in the SST performance. Furthermore, a critical value of the overflow rate (q(crit)) was found at which a pronounced large scale circulation pattern develops in the vertical plane, the density current in such a way hitting the outer wall of the SST, turning then to the vertical direction accompanied with significant flow velocities. This phenomenon strengthens with the hydraulic load and can entrain part of the sludge thus resulting in unfavourable turbid effluent. As a representative case study an operating circular SST most commonly used in practice was investigated. Focusing on the sludge return strategies, it was found that up to a threshold peak flow rate the most efficient way is to keep the return sludge flow rate constant, at 0.4Q(MAX). However, once the inflow rate exceeds the threshold value the return sludge flow rate should be slowly increased up to 0.6Q(MAX), performed in a delayed manner, about 20-30 min after the threshold value is exceeded. For preserving the methodology outlined in the present paper, other types of SSTs, however, need further individual investigations. Copyright © 2012 Elsevier Ltd. All rights reserved.

Early Student Support for SST Control by Subsurface Mixing during Indian Ocean Monsoons

DTIC Science & Technology

2015-09-30

Lee and Rainville), and NRL (Wijesekera). OBJECTIVES The objectives of this project are to: 1. use satellite-measured SSS , SST, and SSH to...forcing, and 5. synthesize the above information and products to examine links and feedbacks between the SST and SSS of the SLD and local precipitation

Estimation of sea surface temperature from remote sensing in the 11to 13-micron window region

NASA Technical Reports Server (NTRS)

Prabhakara, C.; Kunde, V. G.; Dalu, G.

1974-01-01

The Nimbus 3 and 4 Iris spectral data in the 11- to 13-micron water vapor window region are analyzed to determine the sea surface temperature (SST). The high spectral resolution data of Iris are averaged over approximately 1-micron-wide intervals to simulate channels of a radiometer to measure the SST. In the present exploratory study, three such channels in the 775- to 960-per cm (12.9-10.5 micron) region are utilized to measure the SST over cloud-free oceans. However, two of these channels are sufficient in routine SST determination. The differential absorption properties of water vapor in the two channels make it possible to determine the water vapor absorption correction without detailed knowledge of the vertical profiles of temperature and water vapor. The feasibility of determining the SST is demonstrated globally with Nimbus 3 data, where cloud-free areas can be selected with the help of albedo data from the medium-resolution infrared radiometer experiment on board the same satellite. The SST derived from this technique agrees with the measurements made by ships to about 1 C.-

On the Regulation of the Pacific Warm Pool Temperature

NASA Technical Reports Server (NTRS)

Chou, Ming-Dah; Chou, Sue-Hsien; Chan, Pui-King; Lau, William K. M. (Technical Monitor)

2002-01-01

In the tropical western Pacific, regions of the highest sea surface temperature (SST) and the largest cloud cover are found to have the largest surface heating, primarily due to the weak evaporative cooling associated with weak winds. This situation is in variance with the suggestions that the temperature in the Pacific warm pool is regulated either by the reduced solar heating due to an enhanced cloudiness or by the enhanced evaporative cooling due to an elevated SST. It is clear that an enhanced surface heating in an enhanced convection region is not sustainable and must be interrupted by variations in large-scale atmospheric circulation. As the deep convective regions shift away from regions of high SST due primarily to seasonal variation and secondarily to interannual variation of the large-scale atmospheric and oceanic circulation, both trade wind and evaporative cooling in the high SST region increase, leading to a reduction in SST. We conclude that the evaporative cooling associated with the seasonal and interannual variations of trade winds in the primary factor that prevent the warm pool SST from increasing to a value much higher than what is observed.

Comparison of two Centennial-scale Sea Surface Temperature Datasets in the Regional Climate Change Studies of the China Seas

NASA Astrophysics Data System (ADS)

Qingyuan, Wang; Yanan, Wang; Yiwei, Liu

2017-08-01

Two widely used sea surface temperature (SST) datasets are compared in this article. We examine characteristics in the climate variability of SST in the China Seas.Two series yielded almost the same warming trend for 1890-2013 (0.7-0.8°C/100 years). However, HadISST1 series shows much stronger warming trends during 1961-2013 and 1981-2013 than that of COBE SST2 series. The disagreement between data sets was marked after 1981. For the hiatus period 1998-2013, the cooling trends of HadISST1 series is much lower than that of COBE SST2. These differences between the two datasets are possibly caused by the different observations which are incorporated to fill with data-sparse regions since 1982. Those findings illustrate that there are some uncertainties in the estimate of SST warming patterns in certain regions. The results also indicate that the temporal and spatial deficiency of observed data is still the biggest handicap for analyzing multi-scale SST characteristics in regional area.

Some analyses of the chemistry and diffusion of SST exhaust materials during phase 3 of the wake period. [in lower stratosphere

NASA Technical Reports Server (NTRS)

Hilst, G. R.; Donaldson, C. D.; Contiliano, R. M.

1973-01-01

In the generally stably stratified lower stratosphere, SST exhaust plumes could spend a significant length of time in a relatively undispersed state. This effort has utilized invariant modeling techniques to simulate the separate and combined effects of atmospheric turbulence, turbulent diffusion, and chemical reactions of SST exhaust materials in the lower stratosphere. The primary results to date are: (1) The combination of relatively slow diffusive mixing and rapid chemical reactions during the Phase III wake period minimizes the effect of SST exhausts on O3 depletion by the so-called NOx catalytic cycle. While the SST-produced NO is substantially above background concentrations, it appears diffusive mixing of NO and O3 is simply too slow to produce the O3 depletions originally proposed. (2) The time required to dilute the SST exhaust plume may be a significant fraction of the total time these materials are resident in the lower stratosphere. If this is the case, then prior estimates of the environmental impact of these materials must be revised significantly downward.

The single mirror small size telescope (SST-1M) of the Cherenkov Telescope Array

NASA Astrophysics Data System (ADS)

Aguilar, J. A.; Bilnik, W.; Borkowski, J.; Cadoux, F.; Christov, A.; della Volpe, D.; Favre, Y.; Heller, M.; Kasperek, J.; Lyard, E.; Marszałek, A.; Moderski, R.; Montaruli, T.; Porcelli, A.; Prandini, E.; Rajda, P.; Rameez, M.; Schioppa, E., Jr.; Troyano Pujadas, I.; Zietara, K.; Blocki, J.; Bogacz, L.; Bulik, T.; Frankowski, A.; Grudzinska, M.; Idźkowski, B.; Jamrozy, M.; Janiak, M.; Lalik, K.; Mach, E.; Mandat, D.; Michałowski, J.; Neronov, A.; Niemiec, J.; Ostrowski, M.; Paśko, P.; Pech, M.; Schovanek, P.; Seweryn, K.; Skowron, K.; Sliusar, V.; Stawarz, L.; Stodulska, M.; Stodulski, M.; Toscano, S.; Walter, R.; WiÈ©cek, M.; Zagdański, A.

2016-07-01

The Small Size Telescope with Single Mirror (SST-1M) is one of the proposed types of Small Size Telescopes (SST) for the Cherenkov Telescope Array (CTA). The CTA south array will be composed of about 100 telescopes, out of which about 70 are of SST class, which are optimized for the detection of gamma rays in the energy range from 5 TeV to 300 TeV. The SST-1M implements a Davies-Cotton optics with a 4 m dish diameter with a field of view of 9°. The Cherenkov light produced in atmospheric showers is focused onto a 88 cm wide hexagonal photo-detection plane, composed of 1296 custom designed large area hexagonal silicon photomultipliers (SiPM) and a fully digital readout and trigger system. The SST-1M camera has been designed to provide high performance in a robust as well as compact and lightweight design. In this contribution, we review the different steps that led to the realization of the telescope prototype and its innovative camera.

Operational use of high-resolution sst in a coupled sea ice-ocean model

NASA Astrophysics Data System (ADS)

Albretsen, A.

2003-04-01

A high-latitude, near real time, sea surface temperature (SST) product with 10 km resolution is developed at the Norwegian Meteorological Institute (met.no) through the EUMETSAT project OSI-SAF (Ocean and Sea Ice Satellite Application Facility). The product covers the Atlantic Ocean from 50N to 90N and is produced twice daily. A digitized SST and sea ice map is produced manually once a week at the Ice Mapping Service at met.no using all available information from the previous week. This map is the basis for a daily SST analysis, in which the most recent OSI-SAF SST products are successively overlaid. The resulting SST analysis field is then used in a simple data assimilation scheme in a coupled ice-ocean model to perform daily 10 days forecasts of ocean and sea ice variables. Also, the associated OSI-SAF sea ice concentration product, built from different polar orbiting satellites, is assimilated into the sea ice model. Preliminary estimates of impact on forecast skill and error statistics will be presented.

Mesoscale Variation of Mechanisms Contributing to Stability in Rocky Shore Communities

PubMed Central

Valdivia, Nelson; González, Andrés E.; Manzur, Tatiana; Broitman, Bernardo R.

2013-01-01

Environmental fluctuations can generate asynchronous species’ fluctuations and community stability, due to compensatory dynamics of species with different environmental tolerances. We tested this hypothesis in intertidal hard-bottom communities of north-central Chile, where a persistent upwelling centre maintains a mosaic in sea surface temperatures (SST) over 10s of kilometres along the shore. Coastal upwelling implies colder and temporally more stable SST relative to downstream sites. Uni- and multivariate analyses of multiyear timeseries of SST and species abundances showed more asynchronous fluctuations and higher stability in sites characterised by warmer and more variable SST. Nevertheless, these effects were weakened after including data obtained in sites affected by less persistent upwelling centres. Further, dominant species were more stable in sites exposed to high SST variability. The strength of other processes that can influence community stability, chiefly statistical averaging and overyielding, did not vary significantly between SST regimes. Our results provide observational evidence supporting the idea that exogenously driven compensatory dynamics and the stabilising effects of dominant species can determine the stability of ecosystems facing environmental fluctuations. PMID:23326592

Analysis and modeling of the seasonal South China Sea temperature cycle using remote sensing

NASA Astrophysics Data System (ADS)

Twigt, Daniel J.; de Goede, Erik D.; Schrama, Ernst J. O.; Gerritsen, Herman

2007-10-01

The present paper describes the analysis and modeling of the South China Sea (SCS) temperature cycle on a seasonal scale. It investigates the possibility to model this cycle in a consistent way while not taking into account tidal forcing and associated tidal mixing and exchange. This is motivated by the possibility to significantly increase the model’s computational efficiency when neglecting tides. The goal is to develop a flexible and efficient tool for seasonal scenario analysis and to generate transport boundary forcing for local models. Given the significant spatial extent of the SCS basin and the focus on seasonal time scales, synoptic remote sensing is an ideal tool in this analysis. Remote sensing is used to assess the seasonal temperature cycle to identify the relevant driving forces and is a valuable source of input data for modeling. Model simulations are performed using a three-dimensional baroclinic-reduced depth model, driven by monthly mean sea surface anomaly boundary forcing, monthly mean lateral temperature, and salinity forcing obtained from the World Ocean Atlas 2001 climatology, six hourly meteorological forcing from the European Center for Medium range Weather Forecasting ERA-40 dataset, and remotely sensed sea surface temperature (SST) data. A sensitivity analysis of model forcing and coefficients is performed. The model results are quantitatively assessed against climatological temperature profiles using a goodness-of-fit norm. In the deep regions, the model results are in good agreement with this validation data. In the shallow regions, discrepancies are found. To improve the agreement there, we apply a SST nudging method at the free water surface. This considerably improves the model’s vertical temperature representation in the shallow regions. Based on the model validation against climatological in situ and SST data, we conclude that the seasonal temperature cycle for the deep SCS basin can be represented to a good degree. For shallow regions, the absence of tidal mixing and exchange has a clear impact on the model’s temperature representation. This effect on the large-scale temperature cycle can be compensated to a good degree by SST nudging for diagnostic applications.

Mg/Ca Ratios in Coralline Red Algae as Temperature Proxies for Reconstructing Labrador Current Variability

NASA Astrophysics Data System (ADS)

Gamboa, G.; Hetzinger, S.; Halfar, J.; Zack, T.; Kunz, B.; Adey, W.

2009-05-01

Marine ecosystems and fishery productivity in the Northwestern Atlantic have been considerably affected by regional climate and oceanographic changes. Fluctuations of North Atlantic marine climate have been linked in part to a dominant pattern of atmospheric circulation known as the North Atlantic Oscillation, which has a strong influence on transport variability of the Labrador Current (LC). The cold LC originates in the Labrador Sea and flows southbound along the Eastern Canadian coastline causing an important cooling effect on marine waters off the Canadian Atlantic provinces. Although interdecadal and interannual variability of sea surface temperatures (SST) in the LC system have been documented, a long-term pattern has not been identified. In order to better understand the observed ecosystem changes and their relationship with climate variability in the Northwestern Atlantic, a century-scale reconstruction of spatial and temporal variations of the LC is needed. This, however, requires reliable long-term and high-resolution SST records, which are not available from short instrumental observations. Here we present the first century-scale SST reconstructions from the Northwest Atlantic using long-lived coralline red algae. Coralline red algae have a high-Mg calcite skeleton, live in shallow water worldwide and develop annual growth bands. It has previously been demonstrated that subannual resolution SSTs can be obtained from coralline red algal Mg/Ca ratios, a commonly used paleotemperature proxy. Specimens of the long-lived coralline red algae Clathromorphum compactum were collected alive in August 2008 along a latitudinal transect spanning the southern extent of LC flow in Nova Scotia and Newfoundland. This collection is supplemented with specimens from the same region collected in the 1960's. In order to reconstruct spatial and temporal patterns of the LC, selected samples of C. compactum were analyzed for Mg/Ca using Laser Ablation Inductively-Coupled Plasma Mass Spectrometry (LA-ICP-MS). Mg/Ca ratios range from 0.048 to 0.138 (measured in weight %) and relate to water temperatures of -1 to 16°C. Age models were established by comparing annual growth increments (average increment width 350 microns/year) with Mg/Ca cycles. This yielded subannually-resolved Mg/Ca-based SST reconstructions spanning the past century.

Asynchronous Patterns of East Asian Monsoon Climate Proxies during the Past 28 000 Years

NASA Astrophysics Data System (ADS)

Ruan, Y.; Li, L.; Jia, G.; He, J.; Dong, L.; Ma, X.; Shi, J.; Wang, H.

2015-12-01

The monsoon system serves as a "bridge" in the atmosphere; it connects the circulation between high and low latitudes, influencing the most densely populated regions on Earth. However, what role it played in the geological history is still elusive despite its significance. The climate of South China Sea and the ambient land masses are dominated by the East Asian monsoon, composed of the temperature-cooling East Asian winter monsoon (EAWM) and the rain-bearing East Asian summer monsoon (EASM). In this study, high-resolution sea surface temperature (SST), terrestrial input and humidity changes since ~28 ka were reconstructed based on alkenones and long chain n-alkanes records in core MD12-3428 in northern South China Sea. Our results demonstrated complex and dynamic paleoclimatic situations since the last glacial superimposed on the overall glacial-interglacial trend. During the last deglacial, the rising of the sea level can be dated back to 17 ka and ended at ~12 ka, according to the gradual decrease of long chain n-alkanes concentrations. However, the SST warming began at ~15 ka (~2 000 years after the initial sea level uplift) and achieved a relatively stable state in mid-Holocene (~6 000 years after the sea level stablization). The humidity varibility linked with EASM based on C31/C27 and ACL record indicated highly humid conditions within the Bølling/Allerød (B/A) period, followed by a rapid drying towards the glacial level during Younger Dryas (YD). EASM gradually strengthened after YD when the sea level had run up to almost the present state, and weakened after ~6 ka when sea level and SST both reached the plateau. These large fluctuations of C31/C27 and ACL implied that humidity was more sensitive to climate events since the last deglacial when compared with SST and sea level. The asynchronous patterns of East Asian monsoon climate proxies in the present work indicated the complex heat transport and atmospheric circulation between low and high latitudes.

Temperature Calibration of a Northern Gulf of Mexico Siderastrea siderea Coral

NASA Astrophysics Data System (ADS)

Wagner, A. J.; DeLong, K. L.; Kilbourne, K. H.; Richey, J. N.; Jelinek, K.; Hickerson, E.; Slowey, N. C.

2015-12-01

The Gulf of Mexico (GOM) is sensitive to oceanic and atmospheric variability in both the Atlantic and Pacific Oceans (i.e., Atlantic Multidecadal Oscillation (AMO), El Niño Southern Oscillation (ENSO), Pacific North American Pattern (PNA), and Pacific Decadal Oscillation (PDO)). The major GOM current, the Loop Current, feeds the Gulf Stream as it transports oceanic heat to the northern Atlantic Ocean. The northern GOM is the northernmost summer extent of the western hemisphere warm pool (WHWP) that drives oceanic moisture flux and precipitation into the Americas. Decadally-resolved foraminifera reconstructions from the northern GOM indicates SST was 2 to 4ºC colder on average than today during the Little Ice Age (LIA, ~1850), whereas a subannually-resolved coral reconstruction from the southeastern GOM find 1.5 to 2ºC colder intervals and reduced areal extent of the WHWP on interannual time scales during some intervals of the LIA. However, records capable of resolving annual and subannual SST variability from the northern GOM, necessary for investigating WHWP northern extent, are still lacking. Here we present a new temperature reconstruction for the northern GOM derived from strontium-to-calcium (Sr/Ca) ratios of approximately monthly samples milled from a Siderastrea siderea coral core collected from the Flower Garden Banks National Marine Sanctuary (FGBNMS; 27° 52.5'N, 93° 49'W) growing at a water depth of 20 m. Coral Sr/Ca is calibrated to reef temperature data from FGBNMS Hobotemp data loggers near the reef cap in ~22 m water depth (1986-2004) and to NOAA OISST (1981-2004), which co-varies with the reef temperature (r=0.95, p<0.05, n=146) and consistently captures winter values in reef temperature with slightly warmer summers (0.9ºC on average). The Sr/Ca-SST calibration slope (-0.043, r=-0.89, n=136, p<0.01 for reef temperature; -0.039, r=-0.94, n=275, p<0.01 for OISST) agrees well with published coral Sr/Ca-SST calibrations for S. siderea in the southeastern GOM from shallower water depths.

Warming off southwestern Japan linked to distributional shifts of subtidal canopy-forming seaweeds.

PubMed

Tanaka, Kouki; Taino, Seiya; Haraguchi, Hiroko; Prendergast, Gabrielle; Hiraoka, Masanori

2012-11-01

To assess distributional shifts of species in response to recent warming, historical distribution records are the most requisite information. The surface seawater temperature (SST) of Kochi Prefecture, southwestern Japan on the western North Pacific, has significantly risen, being warmed by the Kuroshio Current. Past distributional records of subtidal canopy-forming seaweeds (Laminariales and Fucales) exist at about 10-year intervals from the 1970s, along with detailed SST datasets at several sites along Kochi's >700 km coastline. In order to provide a clear picture of distributional shifts of coastal marine organisms in response to warming SST, we observed the present distribution of seaweeds and analyzed the SST datasets to estimate spatiotemporal SST trends in this coastal region. We present a large increase of 0.3°C/decade in the annual mean SST of this area over the past 40 years. Furthermore, a comparison of the previous and present distributions clearly showed the contraction of temperate species' distributional ranges and expansion of tropical species' distributional ranges in the seaweeds. Although the main temperate kelp Ecklonia (Laminariales) had expanded their distribution during periods of cooler SST, they subsequently declined as the SST warmed. Notably, the warmest SST of the 1997-98 El Niño Southern Oscillation event was the most likely cause of a widespread destruction of the kelp populations; no recovery was found even in the present survey at the formerly habitable sites where warm SSTs have been maintained. Temperate Sargassum spp. (Fucales) that dominated widely in the 1970s also declined in accordance with recent warming SSTs. In contrast, the tropical species, S. ilicifolium, has gradually expanded its distribution to become the most conspicuously dominant among the present observations. Thermal gradients, mainly driven by the warming Kuroshio Current, are presented as an explanation for the successive changes in both temperate and tropical species' distributions.

Immunohistochemical expression and colocalization of somatostatin, carboxypeptidase-E and prohormone convertases 1 and 2 in rat brain.

PubMed

Billova, S; Galanopoulou, A S; Seidah, N G; Qiu, X; Kumar, U

2007-06-29

The processing of many peptides for their maturation in target tissue depends upon the presence of sorting receptor. Several previous studies have predicted that carboxypeptidase-E (CPE), prohormone convertase 1 (PC1) and prohormone convertase 2 (PC2) may function as sorting elements for somatostatin (SST) for its maturation and processing to appropriate targets. However, nothing is currently known about whether brain, neuronal culture or even endocrine cells express SST, CPE, PC1 and PC2 and exhibit colocalization. Accordingly, in the present study using peroxidase immunohistochemistry, double-labeled indirect immunofluorescence immunohistochemistry and Western blot analysis, we mapped the distributional pattern of SST, CPE, PC1 and PC2 in different rat brain regions. Additionally, we also determined the colocalization of SST with CPE, PC1 and PC2 as well as colocalization of CPE with PC1 and PC2. The localization of SST, CPE, PC1 and PC2 reveals a distinct and region specific distribution pattern in the rat brain. Using an indirect double-label immunofluorescence method we observed selective neuron specific colocalization in a region specific manner in cortex, striatum and hippocampus. These studies provide the first evidence for colocalization between SST, CPE, PC1 and PC2 as well as CPE with PC1 and PC2. SST in cerebral cortex colocalized in pyramidal and non-pyramidal neurons with CPE, PC1 and PC2. Most importantly, in striatum and hippocampus colocalization was mostly observed selectively and preferentially in interneurons. CPE is also colocalized with PC1 and PC2 in a region specific manner. The data presented here provide a new insight into the distribution and colocalization of SST, CPE, PC1 and PC2 in rat brain. Taken together, our data anticipate the possibility that CPE, PC1 and PC2 might be potential target for the maturation of SST.

The super greenhouse effect in a warming world: the role of dynamics and thermodynamics

NASA Astrophysics Data System (ADS)

Kashinath, Karthik; O'Brien, Travis; Collins, William

2016-04-01

Over warm tropical oceans the increase in greenhouse trapping with increasing SST can be faster than that of the surface emission, resulting in a decrease in clear sky outgoing longwave radiation at the top of the atmosphere (OLR) when SST increases, also known as the super greenhouse effect (SGE). If the SGE is directly linked to SST changes, there are profound implications for positive climate feedbacks in the tropics. We show that CMIP5 models perform well in simulating the observed clear-sky greenhouse effect in the present day. Using global warming experiments we show that the onset and shutdown SST of the SGE, as well as the magnitude of the SGE, increase as the convective threshold SST increases. To account for an increasing convective threshold SST we use an invariant coordinate for convection proposed in a recent study [Williams et al., GRL (2009)]. However, even after accounting for the increase in tropical SST (by normalizing the SGE by surface emission) and accounting for the increase in the threshold temperature for convection (by using the invariant coordinate) we find that the models predict a distinct increase in the clear-sky greenhouse effect in a warmed world. This suggests that thermodynamics (i.e. SST) plays a crucial role in regulating the increasing clear sky greenhouse effect in a warming world. We use theoretical arguments to estimate this increase in SGE and derive its dependence on SST. Finally, as shown in previous studies, we confirm that the increase in the clear-sky greenhouse effect is primarily due to upper tropospheric moistening. Although the absolute increase in upper tropospheric water vapor is small compared to that of the lower troposphere, since the absorptivity scales with fractional changes in water vapor, the contribution of the upper troposphere is more significant, as shown by Chung et al., PNAS (2014).

ST2 and IL-33 in Pregnancy and Pre-Eclampsia

PubMed Central

Snider, James V.; Tannetta, Dionne S.; Child, Tim; Redman, Christopher W. G.; Sargent, Ian L.

2011-01-01

Normal pregnancy is associated with a mild systemic inflammatory response and an immune bias towards type 2 cytokine production, whereas pre-eclampsia is characterized by a more intense inflammatory response, associated with endothelial dysfunction and a type 1 cytokine dominance. Interleukin (IL)-33 is a newly described member of the IL-1 family, which binds its receptor ST2L to induce type 2 cytokines. A soluble variant of ST2 (sST2) acts as a decoy receptor to regulate the activity of IL-33. In this study circulating IL-33 and sST2 were measured in each trimester of normal pregnancy and in women with pre-eclampsia. While IL-33 did not change throughout normal pregnancy, or between non-pregnant, normal pregnant or pre-eclamptic women, sST2 was significantly altered. sST2 was increased in the third trimester of normal pregnancy (p<0.001) and was further increased in pre-eclampsia (p<0.001). This increase was seen prior to the onset of disease (p<0.01). Pre-eclampsia is a disease caused by placental derived factors, and we show that IL-33 and ST2 can be detected in lysates from both normal and pre-eclampsia placentas. ST2, but not IL-33, was identified on the syncytiotrophoblast layer, whereas IL-33 was expressed on perivascular tissue. In an in vitro placental perfusion model, sST2 was secreted by the placenta into the ‘maternal’ eluate, and placental explants treated with pro-inflammatory cytokines or subjected to hypoxia/reperfusion injury release more sST2, suggesting the origin of at least some of the increased amounts of circulating sST2 in pre-eclamptic women is the placenta. These results suggest that sST2 may play a significant role in pregnancies complicated by pre-eclampsia and increased sST2 could contribute to the type 1 bias seen in this disorder. PMID:21949719

A global monthly sea surface temperature climatology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shea, D.J.; Trenberth, K.E.; Reynolds, R.W.

1992-09-01

The paper presents a new global 2 deg x 2 deg monthly sea surface temperature (SST) climatology, referred here to as the Shea-Trenberth-Reynolds (STR) climatology, which was derived by modifying a 1950-1979-based SST climatology from the Climate Analysis Center (CAC), by using data from the Comprehensive Ocean-Atmosphere Data Set to improve the SST estimates in the regions of the Kuroshio and the Gulf Stream. A comparison of the STR climatology with the Alexander and Mobley SST climatology showed that the STR climatology is warmer in the Northern Hemisphere, and colder poleward of 45 deg S. 22 refs.

North to Alaska: Evidence for conveyor belt transport of Dungeness crab larvae along the west coast of the United States and Canada

USGS Publications Warehouse

Park, W.; Douglas, David C.; Shirley, Thomas C.

2007-01-01

We propose and evaluate the hypothesis that Dungeness crab (Cancer magister) larvae from the northwestern coast of the United States and Canada can be transported northward to southeastern Alaska. Larvae collected in southeastern Alaska during May and June 1997–2004 had abundances and stages that varied seasonally, interannually, and spatially. An unexpected presence of late-stage larvae in spring raises a question regarding their origin, and the most plausible explanation is that they hatched off the northern Washington and British Columbia coasts and were transported to southeastern Alaska. Buoy drift tracks support the hypothesis that larvae released off the northern Washington and British Columbia coasts during the peak hatching season can be physically transported to southeastern Alaska, arriving as late-stage larvae in May and June, when local larvae are only beginning to hatch. A northward spring progression of monthly mean 7°C SST isotherms and phytoplankton blooms provide further evidence that environmental conditions are conducive for larval growth and metabolism during the transport period. The proposed larval transport suggests possible unidirectional gene flow between southern and northern populations of Dungeness crabs in southeastern Alaska.

Advanced Vehicle Concepts and Implications for NextGen

NASA Technical Reports Server (NTRS)

Blake, Matt; Smith, Jim; Wright, Ken; Mediavilla Ricky; Kirby, Michelle; Pfaender, Holger; Clarke, John-Paul; Volovoi, Vitali; Dorbian, Christopher; Ashok, Akshay;

Differential effect of blood collection tubes on total free fatty acids (FFA) and total triiodothyronine (TT3) concentration: a model for studying interference from tube constituents.

PubMed

Bowen, Raffick A R; Vu, Chi; Remaley, Alan T; Hortin, Glen L; Csako, Gyorgy

2007-03-01

Besides total triiodothyronine (TT3), total free fatty acids (FFA) concentrations were higher with serum separator tube (SST) than Vacuette tubes. The effects of surfactant, rubber stopper, and separator gel from various tubes were investigated on FFA, beta-hydroxybutyrate (beta-HB), and TT3 with 8 different tube types in blood specimens of apparently healthy volunteers. Compared to Vacuette tubes, serum FFA and TT3 concentrations were significantly higher in SST than glass tubes. Reformulated SST eliminated the increase in TT3 but not FFA. No significant difference was observed for beta-HB concentration among tube types. Surfactant and rubber stoppers from the different tube types significantly increased TT3 but not FFA and beta-HB concentrations. Agitation of whole blood but not serum or plasma specimens with separator gel from SST, reformulated SST and plasma preparation tube (PPT) tubes compared to Vacuette tubes gave higher FFA but not beta-HB levels. Unidentified component(s) from the separator gel in SST, reformulated SST and PPT tubes cause falsely high FFA concentration. In contrast to TT3, falsely high FFA results require exposure of whole blood and not serum to tube constituent(s). The approach employed here may serve as a model for assessing interference(s) from tube constituent(s).

Genome-Scale Analysis Reveals Sst2 as the Principal Regulator of Mating Pheromone Signaling in the Yeast Saccharomyces cerevisiae†

PubMed Central

Chasse, Scott A.; Flanary, Paul; Parnell, Stephen C.; Hao, Nan; Cha, Jiyoung Y.; Siderovski, David P.; Dohlman, Henrik G.

2006-01-01

A common property of G protein-coupled receptors is that they become less responsive with prolonged stimulation. Regulators of G protein signaling (RGS proteins) are well known to accelerate G protein GTPase activity and do so by stabilizing the transition state conformation of the G protein α subunit. In the yeast Saccharomyces cerevisiae there are four RGS-homologous proteins (Sst2, Rgs2, Rax1, and Mdm1) and two Gα proteins (Gpa1 and Gpa2). We show that Sst2 is the only RGS protein that binds selectively to the transition state conformation of Gpa1. The other RGS proteins also bind Gpa1 and modulate pheromone signaling, but to a lesser extent and in a manner clearly distinct from Sst2. To identify other candidate pathway regulators, we compared pheromone responses in 4,349 gene deletion mutants representing nearly all nonessential genes in yeast. A number of mutants produced an increase (sst2, bar1, asc1, and ygl024w) or decrease (cla4) in pheromone sensitivity or resulted in pheromone-independent signaling (sst2, pbs2, gas1, and ygl024w). These findings suggest that Sst2 is the principal regulator of Gpa1-mediated signaling in vivo but that other proteins also contribute in distinct ways to pathway regulation. PMID:16467474

The Influence of Ocean on Typhoon Nuri (2008)

NASA Astrophysics Data System (ADS)

Sun, J.; Oey, L. Y.; Xu, F.; Lin, Y.; Huang, S. M.; Chang, R.

2014-12-01

The influence of ocean on typhoon Nuri (2008) is investigated in this study using the WRF numerical model. Typhoon Nuri formed over the warm pool of the western North Pacific. The storm traversed west-northwestward and became a Category 3 typhoon over the Kuroshio east of the Luzon Strait and weakened as it moved across South China Sea. Three types of SST: NCEP RTG_SST (Real-time，global，sea surface temperature) GHRsst (Group for High Resolution Sea Surface Temperature) and SST from the ATOP North Pacific ocean model [Oey et al 2014, JPO] are used in WRF to test the effect of ocean on the intensity of typhoon Nuri. The typhoon intensity and track are also compared with simulations using different microphysics schemes but with fixed SST. The results show that thermodynamic control through ocean response is the dominant factor which determines Nuri's intensity. The simulated intensity agrees well with the observed intensity when ATOP SST is used, while using NCEP SST and GHRsst yield errors both in intensity and timing of maximum intensity. Over the Kuroshio, the thicker depth of 26 ℃ from ATOP provides stronger heating for the correct timing of intensification of Nuri. In South China Sea, the storm weakened because of cooled SST through ocean mixing by inertial resonance. A new way of explaining typhoon intensification though PV is proposed.

Assimilation for skin SST in the NASA GEOS atmospheric data assimilation system

PubMed Central

Akella, Santha; Todling, Ricardo; Suarez, Max

2018-01-01

The present article describes the sea surface temperature (SST) developments implemented in the Goddard Earth Observing System, Version 5 (GEOS-5) Atmospheric Data Assimilation System (ADAS). These are enhancements that contribute to the development of an atmosphere-ocean coupled data assimilation system using GEOS. In the current quasi-operational GEOS-ADAS, the SST is a boundary condition prescribed based on the OSTIA product, therefore SST and skin SST (Ts) are identical. This work modifies the GEOS-ADAS Ts by modeling and assimilating near sea surface sensitive satellite infrared (IR) observations. The atmosphere-ocean interface layer of the GEOS atmospheric general circulation model (AGCM) is updated to include near surface diurnal warming and cool-skin effects. The GEOS analysis system is also updated to directly assimilate SST-relevant Advanced Very High Resolution Radiometer (AVHRR) radiance observations. Data assimilation experiments designed to evaluate the Ts modification in GEOS-ADAS show improvements in the assimilation of radiance observations that extends beyond the thermal IR bands of AVHRR. In particular, many channels of hyperspectral sensors, such as those of the Atmospheric Infrared Sounder (AIRS), and Infrared Atmospheric Sounding Interferometer (IASI) are also better assimilated. We also obtained improved fit to withheld, in-situ buoy measurement of near-surface SST. Evaluation of forecast skill scores show marginal to neutral benefit from the modified Ts. PMID:29628531

Relative roles of differential SST warming, uniform SST warming and land surface warming in determining the Walker circulation changes under global warming

NASA Astrophysics Data System (ADS)

Zhang, Lei; Li, Tim

2017-02-01

Most of CMIP5 models projected a weakened Walker circulation in tropical Pacific, but what causes such change is still an open question. By conducting idealized numerical simulations separating the effects of the spatially uniform sea surface temperature (SST) warming, extra land surface warming and differential SST warming, we demonstrate that the weakening of the Walker circulation is attributed to the western North Pacific (WNP) monsoon and South America land effects. The effect of the uniform SST warming is through so-called "richest-get-richer" mechanism. In response to a uniform surface warming, the WNP monsoon is enhanced by competing moisture with other large-scale convective branches. The strengthened WNP monsoon further induces surface westerlies in the equatorial western-central Pacific, weakening the Walker circulation. The increase of the greenhouse gases leads to a larger land surface warming than ocean surface. As a result, a greater thermal contrast occurs between American Continent and equatorial Pacific. The so-induced zonal pressure gradient anomaly forces low-level westerly anomalies over the equatorial eastern Pacific and weakens the Walker circulation. The differential SST warming also plays a role in driving low-level westerly anomalies over tropical Pacific. But such an effect involves a positive air-sea feedback that amplifies the weakening of both east-west SST gradient and Pacific trade winds.

Development of a Support Application and a Textbook for Practicing Facial Expression Detection for Students with Visual Impairment

ERIC Educational Resources Information Center

Saito, Hirotaka; Ando, Akinobu; Itagaki, Shota; Kawada, Taku; Davis, Darold; Nagai, Nobuyuki

2017-01-01

Until now, when practicing facial expression recognition skills in nonverbal communication areas of SST, judgment of facial expression was not quantitative because the subjects of SST were judged by teachers. Therefore, we thought whether SST could be performed using facial expression detection devices that can quantitatively measure facial…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reidel, Stephen P.

This chapter summarizes the geology of the single-shell tank (SST) farms in the context of the region’s geologic history. This chapter is based on the information in the geology data package for the SST waste management areas and SST RFI Appendix E, which builds upon previous reports on the tank farm geology and Integrated Disposal Facility geology with information available after those reports were published.

Sustained Shared Thinking in an Early Childhood Setting: An Exploration of Practitioners' Perspectives

ERIC Educational Resources Information Center

Purdon, Anne

2016-01-01

Sustained shared thinking (SST) has been identified in the Teachers Standards (Early Years) (2013) as contributing to good progress and outcomes by children. In this paper, I define SST and discuss the outcomes of a study of practitioners' understandings of SST, its challenges and benefits. Writing frames, questionnaires and focus group interviews…

Investigating the sensitivity of hurricane intensity and trajectory to sea surface temperatures using the regional model WRF

NASA Astrophysics Data System (ADS)

Kilic, Cevahir; Raible, Christoph C.

2015-04-01

It is well known that the sea surface temperature (SST) has an influence on the development and intensification of tropical cyclones (TCs). This influence has become even more important during the past decades, as TCs show an intensification, which goes along with an increase in SSTs. The influence of sea surface temperature (SST) anomalies on the hurricane characteristics are investigated in a set of sensitivity experiments employing the Weather Research and Forecasting (WRF) model. The idealised experiments are performed for the case of Hurricane Katrina in 2005. (Kilic and Raible, 2013) The first set of sensitivity experiments with basin-wide changes of the SST magnitude shows that the intensity goes along with changes in the SST, i.e., an increase in SST leads to an intensification of Katrina. Additionally, the trajectory is shifted to the west (east), with increasing (decreasing) SSTs. The main reason is a strengthening of the background flow. To gain further insights in the dynamics, the potential vorticity (PV) and its tendency (PVT) are analysed. A positive PVT is located to the moving direction relative to the TC centre. Splitting the PVT in the horizontal advection, vertical advection, and diabatic heating terms, we find that mainly the horizontal advection term contributes to this PVT maximum, due to a steering by strong environmental flow. The impact of the diabatic heating is of minor importance and, hence, the TC motion is dominated by horizontal advection. The amount of the horizontal advection as well as the amount of the diabatic heating rise with increasing SST due to the enhanced Carnot cycle. The second set of experiments investigates the influence of Loop Current eddies idealised by localised SST anomalies. The intensity of Hurricane Katrina is enhanced with increasing SSTs close to the core of a TC. Negative nearby SST anomalies reduce the intensity. The trajectory only changes if positive SST anomalies are located west or north of the hurricane centre. In this case the hurricane is attracted by the SST anomaly which causes an additional moisture source and increased vertical winds. This study confirm the linear relation between SST and TC intensity. However, in case of localised SST anomalies, the relative location to the TC core determes the gradient of the linear relation. The gradient decreases with increasing distance between SST anomaly and initialisation point. The anomalies located west and north of the initialisation point have a stronger impact than the ones located south and east, as they lie in the moving direction of the TC. Further, in terms of magnitude and pattern, the horizontal advection term of PVT does not strongly differ from the reference simulation. However, the pattern of diabatic heating term differs: A maximum of diabatic heating is still located in moving direction, but additionally the diabatic heating is found in the spiral rain bands. Thus, the vortex is drifted to the SST anomaly due to the asymmetry in the TC circulation induced by the diabatic heating term of the PVT. References Kilic, C., and C. C. Raible, Investigating the sensitivity of hurricane intensity and trajectory to sea surface temperatures using the regional model WRF, METEOROLOGISCHE ZEITSCHRIFT, 22(6), 685-698, 2013.

Contrasting Indian Ocean SST Variability With and Without ENSO Influence: A Coupled Atmosphere-Ocean GCM Study

NASA Technical Reports Server (NTRS)

Yu, Jin-Yi; Lau, K. M.

2004-01-01

In this study, we perform experiments with a coupled atmosphere-ocean general circulation model (CGCM) to examine ENSO's influence on the interannual sea surface temperature (SST) variability of the tropical Indian Ocean. The control experiment includes both the Indian and Pacific Oceans in the ocean model component of the CGCM (the Indo-Pacific Run). The anomaly experiment excludes ENSOs influence by including only the Indian Ocean while prescribing monthly-varying climatological SSTs for the Pacific Ocean (the Indian-Ocean Run). In the Indo-Pacific Run, an oscillatory mode of the Indian Ocean SST variability is identified by a multi-channel singular spectral analysis (MSSA). The oscillatory mode comprises two patterns that can be identified with the Indian Ocean Zonal Mode (IOZM) and a basin-wide warming/cooling mode respectively. In the model, the IOZM peaks about 3-5 months after ENSO reaches its maximum intensity. The basin mode peaks 8 months after the IOZM. The timing and associated SST patterns suggests that the IOZM is related to ENSO, and the basin- wide warming/cooling develops as a result of the decay of the IOZM spreading SST anomalies from western Indian Ocean to the eastern Indian Ocean. In contrast, in the Indian-Ocean Run, no oscillatory modes can be identified by the MSSA, even though the Indian Ocean SST variability is characterized by east-west SST contrast patterns similar to the IOZM. In both control and anomaly runs, IOZM-like SST variability appears to be associated with forcings from fluctuations of the Indian monsoon. Our modeling results suggest that the oscillatory feature of the IOZM is primarily forced by ENSO.

Small change, big difference: Sea surface temperature distributions for tropical coral reef ecosystems, 1950-2011

NASA Astrophysics Data System (ADS)

Lough, J. M.

2012-09-01

Changes in tropical sea surface temperature (SST) are examined over the period 1950-2011 during which global average temperature warmed by 0.4°C. Average tropical SST is warming about 70% of the global average rate. Spatially, significant warming between the two time periods, 1950-1980 and 1981-2011, has occurred across 65% of the tropical oceans. Coral reef ecosystems occupy 10% of the tropical oceans, typically in regions of warmer (+1.8°C) and less variable SST (80% of months within 3.3°C range) compared to non-reef areas (80% of months within 7.0°C range). SST is a primary controlling factor of coral reef distribution and coral reef organisms have already shown their sensitivity to the relatively small amount of warming observed so far through, for example, more frequent coral bleaching events and outbreaks of coral disease. Experimental evidence is also emerging of possible thermal thresholds in the range 30°C-32°C for some physiological processes of coral reef organisms. Relatively small changes in SST have already resulted in quite large differences in SST distribution with a maximum ‘hot spot’ of change in the near-equatorial Indo-Pacific which encompasses both the Indo-Pacific warm pools and the center of coral reef biodiversity. Identification of this hot spot of SST change is not new but this study highlights its significance with respect to tropical coral reef ecosystems. Given the modest amount of warming to date, changes in SST distribution are of particular concern for coral reefs given additional local anthropogenic stresses on many reefs and ongoing ocean acidification likely to increasingly compromise coral reef processes.

A teleconnection study of interannual sea surface temperature fluctuations in the northern North Atlantic and precipitation and runoff over Western Siberia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peng, S.; Mysak, L.A.

The spatial distributions of northern North Atlantic sea surface temperature and the high-latitude Northern Hemisphere sea level pressure anomalies averaged over six consecutive warm SST winters (1951-1956) and six consecutive cold SST winters (1971-1976) are examined. Three SLP anomaly difference (i.e., warm - cold winters) centers, significant at the 5% level, are observed over the northern North Atlantic, Europe, and western Siberia. This anomaly pattern is consistent in principle with what was identified in a related analyses by Palmer and Sun, who used composite data from selected winter months. The SLP difference centers over the northern North Atlantic and westernmore » Siberia are in phase. The impact of the latter center upon the runoff from the underlying Ob and Yenisey rivers and especially the teleconnection between SST anomalies in the northern North Atlantic and runoff of those two rivers via the atmosphere are investigated. The temporal cross-correlation analyses of 50 years (1930-1979) of records of SST, precipitation, and runoff anomalies indicate that the winter SST anomalies in the northern North Atlantic are significantly correlated with the winter and following summer runoff fluctuations of the Ob and Yenisey rivers. Positive (negative) northern North Atlantic SST anomalies are related to less (more) precipitation, and hence, less (more) runoff, over western Siberia. Discussions of possible physical mechanisms and processes that lead to the above relationships are attempted. The analyses of spatial distributions of precipitation in the warm and cold SST winters suggest that precipitation fluctuations over Europe and western Siberia may be affected by shifts of cyclone tracks associated with the SST variations in the northern North Atlantic. 27 refs., 9 figs.« less

Causes of the large warm bias in the Angola-Benguela Frontal Zone in the Norwegian Earth System Model

NASA Astrophysics Data System (ADS)

Koseki, Shunya; Keenlyside, Noel; Demissie, Teferi; Toniazzo, Thomas; Counillon, Francois; Bethke, Ingo; Ilicak, Mehmet; Shen, Mao-Lin

2018-06-01

We have investigated the causes of the sea surface temperature (SST) bias in the Angola-Benguela Frontal Zone (ABFZ) of the southeastern Atlantic Ocean simulated by the Norwegian Earth System Model (NorESM). Similar to other coupled-models, NorESM has a warm SST bias in the ABFZ of up to 8 °C in the annual mean. Our analysis of NorESM reveals that a cyclonic surface wind bias over the ABFZ drives a locally excessively strong southward (0.05 m/s (relative to observation)) Angola Current displacing the ABFZ southward. A series of uncoupled stand-alone atmosphere and ocean model simulations are performed to investigate the cause of the coupled model bias. The stand-alone atmosphere model driven with observed SST exhibits a similar cyclonic surface circulation bias; while the stand-alone ocean model forced with the reanalysis data produces a warm SST in the ABFZ with a magnitude approximately half of that in the coupled NorESM simulation. An additional uncoupled sensitivity experiment shows that the atmospheric model's local negative surface wind curl generates anomalously strong Angola Current at the ocean surface. Consequently, this contributes to the warm SST bias in the ABFZ by 2 °C (compared to the reanalysis forced simulation). There is no evidence that local air-sea feedbacks among wind stress curl, SST, and sea level pressure (SLP) affect the ABFZ SST bias. Turbulent surface heat flux differences between coupled and uncoupled experiments explain the remaining 2 °C warm SST bias in NorESM. Ocean circulation, upwelling and turbulent heat flux errors all modulate the intensity and the seasonality of the ABFZ errors.

Sensitivity of Surface Temperature to Oceanic Forcing via q-Flux Green’s Function Experiments. Part I: Linear Response Function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Fukai; Lu, Jian; Garuba, Oluwayemi

This paper explores the use of linear response function (LRF) to relate the mean sea surface temperature (SST) response to prescribed ocean heat convergence (q-flux) forcings. Two methods for constructing the LRF based on the fluctuation-dissipation theorem (FDT) and Green’s function (GRF) are examined. A 900-year preindustrial simulation from the Community Earth System Model with a slab ocean (CESM-SOM) is used to estimate the LRF using FDT. For GRF, 106 pairs of CESM-SOM simulations with warm and cold q-flux patches are performed. FDT is found to have skill in estimating the SST response to a q-flux forcing when the localmore » SST response is strong, but it fails in inverse estimation of the q-flux forcing for a given SST pattern. In contrast, GRF is shown to be reasonably accurate in estimating both SST response and q-flux forcing. Possible degradation in FDT may be attributed to insufficient data sampling, significant departures of the SST data from Gaussian, and the non-normality of the constructed operator. The accurately estimated GRF-based LRF is used to (i) generate a global surface temperature sensitivity map that shows the q-flux forcing in higher latitudes to be three to four times more effective than in low latitudes in producing global surface warming; (ii) identify the most excitable SST mode (neutral vector) resembling Interdecadal Pacific Oscillation; and (iii) estimate a time-invariant q-flux forcing needed for maintaining the GHG-induced SST warming pattern. The GRF experiments will be used to construct LRF for other variables to further explore climate sensitivities and feedbacks.« less

Balance between somatostatin and D2 receptor expression drives TSH-secreting adenoma response to somatostatin analogues and dopastatins.

PubMed

Gatto, Federico; Barbieri, Federica; Gatti, Monica; Wurth, Roberto; Schulz, Stefan; Ravetti, Jean-Louis; Zona, Gianluigi; Culler, Michael D; Saveanu, Alexandru; Giusti, Massimo; Minuto, Francesco; Hofland, Leo J; Ferone, Diego; Florio, Tullio

2012-03-01

First-line therapy for thyrotropin-secreting pituitary adenomas (TSHomas) is neurosurgery, while medical treatment rests mainly on somatostatin analogues. Clinically available sst(2) -preferring analogues, octreotide and lanreotide, induce normalization of hormone levels in approximately 90% of patients and tumour shrinkage in 45%. We evaluated somatostatin 1, 2, 3 and 5 and dopamine D2 receptor expression in tumour samples from three TSHomas, and the relationships between receptor expression, in vitro antiproliferative response and clinical data, including octreotide test and three months of therapy with octreotide long-acting repeatable (LAR). TSHoma cell proliferation was tested in vitro using octreotide, cabergoline and two chimeric compounds, BIM-23A760 and BIM-23A387. All patients showed significant TSH lowering to acute octreotide test, but a hormonal response to long-term treatment was observed in only two patients, showing a high sst(5) /sst(2) ratio. Patient 2, characterized by high expression of sst(2) and sst(1) and a relative lower expression of sst(5) , experienced tachyphylaxis after prolonged octreotide treatment. In vitro, the somatostatin/dopamine receptor agonist BIM-23A760 caused the highest antiproliferative effect among those tested. Combined treatment with octreotide and cabergoline displayed an additive effect of magnitude comparable to that of the other chimeric compound (BIM-23A387). Octreotide resistance was confirmed in cells isolated from the nonresponder patient, although it could be overcome by treatment with the chimeric compounds.   A high sst(5) /sst(2) ratio might be predictive of a positive outcome to long-term treatment with somatostatin analogues in TSHomas. Moreover, combined somatostatin and D(2) receptor targeting might be considered as a potential tool to improve the response rate in octreotide-resistant tumours. © 2012 Blackwell Publishing Ltd.

Equilibrium Atmospheric Response to North Atlantic SST Anomalies.

NASA Astrophysics Data System (ADS)

Kushnir, Yochanan; Held, Isaac M.

1996-06-01

The equilibrium general circulation model (GCM) response to sea surface temperature (SST) anomalies in the western North Atlantic region is studied. A coarse resolution GCM, with realistic lower boundary conditions including topography and climatological SST distribution, is integrated in perpetual January and perpetual October modes, distinguished from one another by the strength of the midlatitude westerlies. An SST anomaly with a maximum of 4°C is added to the climatological SST distribution of the model with both positive and negative polarity. These anomaly runs are compared to one another, and to a control integration, to determine the atmospheric response. In all cases warming (cooling) of the midlatitude ocean surface yields a warming (cooling) of the atmosphere over and to the east of the SST anomaly center. The atmospheric temperature change is largest near the surface and decreases upward. Consistent with this simple thermal response, the geopotential height field displays a baroclinic response with a shallow anomalous low somewhat downstream from the warm SST anomaly. The equivalent barotropic, downstream response is weak and not robust. To help interpret the results, the realistic GCM integrations are compared with parallel idealized model runs. The idealized model has full physics and a similar horizontal and vertical resolution, but an all-ocean surface with a single, permanent zonal asymmetry. The idealized and realistic versions of the GCM display compatible response patterns that are qualitatively consistent with stationary, linear, quasigeostrophic theory. However, the idealized model response is stronger and more coherent. The differences between the two model response patterns can be reconciled based on the size of the anomaly, the model treatment of cloud-radiation interaction, and the static stability of the model atmosphere in the vicinity of the SST anomaly. Model results are contrasted with other GCM studies and observations.

Long-term changes in the Northwestern Atlantic and Mediterranean SST from 1982 to 2016: A contribution of the Operational Oceanography to the determination of the present day Climate

NASA Astrophysics Data System (ADS)

Artale, Vincenzo; Buongiorno Nardelli, Bruno; Marullo, Salvatore; Pisano, Andrea; Santoleri, Rosalia; Tronconi, Cristina

2017-04-01

Estimating long-term SST changes is crucial to evaluate global warming impact at regional scales. Here, we analyze the Mediterranean (MED) and the Northwestern Atlantic Box (NWA) SST changes over the last 34 years (1982 - 2016) by combining reprocessed (REP) and near-real-time (NRT) data. Actually, the Italian National Research Council (CNR) has recently produced daily (nighttime), 4 km resolution REP MED level 4 datasets (REP L4), also covering the adjacent Atlantic region, based on the latest Pathfinder v5.2 AVHRR dataset (1982-2012). These data represent the longest satellite MED SST L4 time series and are freely distributed through the European Copernicus Marine Environment Monitoring Service (CMEMS). However, as Pathfinder has not yet released an update of its product, the REP data end in 2012. To fill in the gap between 2013 and 2016, we investigated the possibility to extend the time series by using the Mediterranean near real time (NRT), multi-sensor L4 SST data at Ultra-High spatial Resolution (UHR) produced by CNR, which are distributed through CMEMS and now mirrored at GHRSST. Since this product is available since 2008, the consistency with the REP has been assessed. Combining the REP L4 data (1982-2012) and a bias-corrected version of the NRT L4 data (2013-2016), we built the SST time series and provided updated estimates of the MED and NWA SST trends. The analysis shows that The Atlantic Box and The Mediterranean Sea have similar trend behavior until 2008. Afterward the Mediterranean Sea SST continued to increase while the Atlantic Box persisted in its warming pause.

Assimilating Satellite SST Observations into a Diurnal Cycle Model

NASA Astrophysics Data System (ADS)

Pimentel, S.; Haines, K.; Nichols, N. K.

2006-12-01

The wealth of satellite sea surface temperature (SST) data now available opens the possibility of large improvements in SST estimation. However the use of such data is not straight forward; a major difficulty in assimilating satellite observations is that they represent a near surface temperature, whereas in ocean models the top level represents the temperature at a greater depth. During the day, under favourable conditions of clear skies and calm winds, the near surface temperature is often seen to have a diurnal cycle that is picked up in satellite observations. Current ocean models do not have the vertical or temporal resolution to adequately represent this daytime warming. The usual approach is to discard daytime observations as they are considered diurnally `corrupted'. A new assimilation technique is developed here that assimilates observations into a diurnal cycle model. The diurnal cycle of SSTs are modelled using a 1-D mixed layer model with fine near surface resolution and 6 hourly forcing from NWP analyses. The accuracy of the SST estimates are hampered by uncertainties in the forcing data. The extent of diurnal SST warming at a particular location and time is predominately governed by a non-linear response to cloud cover and sea surface wind speeds which greatly affect the air-sea fluxes. The method proposed here combines infrared and microwave SST satellite observations in order to derive corrections to the cloud cover and wind speed values over the day. By adjusting the forcing, SST estimation and air-sea fluxes should be improved and are at least more consistent with each other. This new technique for assimilating SST data can be considered a tool for producing more accurate diurnal warming estimates.

Influence of equatorial QBO (quasi-biennial oscillation) and SST (sea-surface temperature) on polar total ozone, and the 1990 Antarctic ozone hole

DOE Office of Scientific and Technical Information (OSTI.GOV)

Angell, J.K.

1990-09-01

Based on data through 1989, comparisons are made between the variation of total ozone at Resolute, Canada (75{degree}N) and South Pole, and the variation of low-stratospheric temperature at Singapore (reflecting the equatorial QBO) and SST in eastern equatorial Pacific (reflecting the ENSO phenomenon). Total-ozone variations at Resolute have been more closely related to the QBO, whereas the total-ozone variations at South Pole appear to have been almost equally related to QBO and SST. When the average of 50 mb and 30 mb June-July-August (JJA) values of Singapore temperature ({bar T}) increased from one year to the next, the decrease inmore » South Pole springtime total ozone for the same years averaged 21 {plus minus} 14% greater than when {bar T} decreased. When the JJA values of equatorial SST increased from one year to the next, the decrease in South Pole springtime total ozone for the same years averaged 18 {plus minus} 12% greater than when SST decreased. In the 6 cases when JJA values of both Singapore {bar T} and equatorial SST increased from one year to the next, the spring values of South Pole total ozone have decreased, whereas in the 6 cases when both {bar T} and SST decreased from one year to the next, South Pole total ozone has increased. Both Singapore {bar T} and equatorial SST will probably be warmer in JJA of 1990 than they were in JJA of 1989 suggesting, based on these previous relations, an even deeper Antarctic ozone hole in 1990 than in 1989 and ending the biennial variation in depth of the hole of the last 6 years.« less

Late Holocene Sea Surface Temperature Trends in the Eastern Tropical Pacific

NASA Astrophysics Data System (ADS)

Rustic, G. T.; Koutavas, A.; Marchitto, T. M., Jr.

2015-12-01

The Eastern Tropical Pacific (ETP) is a highly dynamic ocean region capable of exerting influencing on global climate as illustrated by the El Niño-Southern Oscillation (ENSO). The sea surface temperature (SST) history of this region in past millennia is poorly constrained due to the lack of in situ records with appropriate resolution. Here we present a ~2700 year sub-centennially resolved SST reconstruction from Mg/Ca ratios of the planktonic foraminifer Globigerinoides ruber from Galápagos sediments. The ETP SST record exhibits a long-term cooling trend of over 0.2°C/ky that is similar to Northern Hemisphere multi-proxy temperature trends suggesting a common origin, likely due to insolation forcing. The ETP remains in-phase with Northern Hemisphere climate records through the warm Roman Climate Optimum (~0-400CE), cooler Dark Ages Cold Period (~450-850CE), and through the peak warming of the Medieval Climate Anomaly (900-1150 CE) when SST is within error of modern. Following peak MCA, the ETP cooled rapidly and then rebounded at ~1500 CE during the coldest portion of the Little Ice Age. Overall the data suggest an out-of-phase relationship during much of the last millennium, which we attribute to dynamical adjustments consistent with the "dynamical ocean thermostat" mechanism. Further evidence for these dynamical adjustments comes from reconstructions of the east-west zonal SST gradient using existing Mg/Ca SST reconstructions from the western Pacific warm pool. The last millennium has been the most dynamic period over the past 2700 years, with significant (~1 °C) SST variability in the ETP and modulation of the zonal gradient. A combination of dynamical and thermodynamic mechanisms are invoked to explain the region's complex SST history.

Expression of Somatostatin, cortistatin, and their receptors, as well as dopamine receptors, but not of neprilysin, are reduced in the temporal lobe of Alzheimer's disease patients.

PubMed

Gahete, Manuel D; Rubio, Alicia; Durán-Prado, Mario; Avila, Jesús; Luque, Raúl M; Castaño, Justo P

2010-01-01

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by severe cognitive deficit, wherein the impairment of episodic memory is the major hallmark. AD patients exhibit augmented accumulation of amyloid-beta (Abeta) and hyperphosphorylated tau protein in specific brain regions. In addition, several neuropeptides/neurotransmitter axes clearly associated with cognitive processes, Abeta turnover, and tau phosphorylation have also been found to be impaired in AD, such as somatostatin (SST)/cortistatin (CST) and dopamine (DA) systems. However, to date there is no precise quantitative data on the expression of these systems in the human brain of AD and normal patients. Here we measured by quantitative real-time PCR the mRNA levels of SST/CST, their receptors (sst1-5 and DA receptors (drd1-5) in addition to neprilysin (a SST-regulated enzyme involved in Abeta degradation) in three regions of the temporal lobe, one of the cortical regions most severely affected by AD. Our results reveal that some components of SST/CST- and DA-axes are divergently altered in the three areas of AD patients. Despite this region-specific regulation, an overall, common reduction of these systems was observed in the temporal lobe of AD patients. Conversely, neprilysin expression was not altered in AD, suggesting that Abeta accumulation observed in AD is due to a lack of neprilysin activation by SST rather than to a reduction of its expression. Collectively, our results define a comprehensive scenario wherein reduction of ssts, drds, and sst ligands SST and CST, could be involved, at least in part, in some of the more important defects observed in AD.

Impact of Monsoon to Aquatic Productivity and Fish Landing at Pesawaran Regency Waters

NASA Astrophysics Data System (ADS)

Kunarso; Zainuri, Muhammad; Ario, Raden; Munandar, Bayu; Prayogi, Harmon

2018-02-01

Monsoon variability influences the productivity processes in the ocean and has different responses in each waters. Furthermore, variability of marine productivity affects to the fisheries resources fluctuation. This research has conducted using descriptive method to investigate the consequences of monsoon variability to aquatic productivity, sea surface temperature (SST), fish catches, and fish season periods at Pesawaran Regency waters, Lampung. Variability of aquatic productivity was determined based on chlorophyll-a indicator from MODIS satellite images. Monsoon variability was governed based on wind parameters and fish catches from fish landing data of Pesawaran fish market. The result showed that monsoon variability had affected to aquatic productivity, SST, and fish catches at Pesawaran Regency waters. Maximum wind speed and lowest SST occurred twice in a year, December to March and August to October, which the peaks were on January (2.55 m/s of wind speed and 29.66°C of SST) and September (2.44 m/s of wind speed and 29.06°C of SST). Also, Maximum aquatic productivity happened on January to March and July to September, which it was arisen simultaneously with maximum wind speed and the peaks was 0.74 mg/m3 and 0.78 mg/m3, on February and August respectively. The data showed that fish catches decreased along with strong wind speed and low SST. However, when weak wind speed and high SST occurred, fish catches increased. The correlation between Catch per Unit Effort (CPUE) with SST, wind speed, and chlorophyll-a was at value 0.76, -0.67, and -0.70, respectively. The high rate fish catches in Pesawaran emerged on March-May and September-December.

Inter-decadal change of the lagged inter-annual relationship between local sea surface temperature and tropical cyclone activity over the western North Pacific

NASA Astrophysics Data System (ADS)

Zhao, Haikun; Wu, Liguang; Raga, G. B.

2018-02-01

This study documents the inter-decadal change of the lagged inter-annual relationship between the TC frequency (TCF) and the local sea surface temperature (SST) in the western North Pacific (WNP) during 1979-2014. An abrupt shift of the lagged relationship between them is observed to occur in 1998. Before the shift (1979-1997), a moderately positive correlation (0.35) between previous-year local SST and TCF is found, while a significantly negative correlation (- 0.71) is found since the shift (1998-2014). The inter-decadal change of the lagged relationship between TCF and local SST over the WNP is also accompanied by an inter-decadal change in the lagged inter-annual relationship between large-scale factors affecting TCs and local SST over the WNP. During 1998-2014, the previous-year local SST shows a significant negative correlation with the mid-level moisture and a significant positive correlation with the vertical wind shear over the main development region of WNP TC genesis. Almost opposite relationships are seen during 1979-1997, with a smaller magnitude of the correlation coefficients. These changes are consistent with the changes of the lagged inter-annual relationship between upper- and lower-level winds and local SST over the WNP. Analyses further suggests that the inter-decadal shift of the lagged inter-annual relationship between WNP TCF and local SST may be closely linked to the inter-decadal change of inter-annual SST transition over the tropical central-eastern Pacific associated with the climate regime shift in the late 1990s. Details on the underlying physical process need further investigation using observations and simulations.

Opposing Effects of Acute versus Chronic Blockade of Frontal Cortex Somatostatin-Positive Inhibitory Neurons on Behavioral Emotionality in Mice

PubMed Central

Soumier, Amelie; Sibille, Etienne

2014-01-01

Reduced expression of somatostatin (SST) is reported across chronic brain conditions including major depression and normal aging. SST is a signaling neuropeptide and marker of gamma-amino butyric acid (GABA) neurons, which specifically inhibit pyramidal neuron dendrites. Studies in auditory cortex suggest that chronic reduction in dendritic inhibition induces compensatory homeostatic adaptations that oppose the effects of acute inhibition. Whether such mechanisms occur in frontal cortex (FC) and affect behavioral outcome is not known. Here, we used two complementary viral vector strategies to examine the effects of acute vs chronic inhibition of SST-positive neurons on behavioral emotionality in adult mice. SST-IRES-Cre mice were injected in FC (prelimbic/precingulate) with CRE-dependent adeno-associated viral (AAV) vector encoding the engineered Gi/o-coupled human muscarinic M4 designer receptor exclusively activated by a designer drug (DREADD-hM4Di) or a control reporter (AAV-DIO-mCherry) for acute or chronic cellular inhibition. A separate cohort was injected with CRE-dependent AAV vectors expressing diphtheria toxin (DTA) to selectively ablate FC SST neurons. Mice were assessed for anxiety- and depressive-like behaviors (defined as emotionality). Results indicate that acute inhibition of FC SST neurons increased behavioral emotionality, whereas chronic inhibition decreased behavioral emotionality. Furthermore, ablation of FC SST neurons also decreased behavioral emotionality under baseline condition and after chronic stress. Together, our results reveal opposite effects of acute and chronic inhibition of FC SST neurons on behavioral emotionality and suggest the recruitment of homeostatic plasticity mechanisms that have implications for understanding the neurobiology of chronic brain conditions affecting dendritic-targeting inhibitory neurons. PMID:24690741

Opposing effects of acute versus chronic blockade of frontal cortex somatostatin-positive inhibitory neurons on behavioral emotionality in mice.

PubMed

Soumier, Amelie; Sibille, Etienne

2014-08-01

Reduced expression of somatostatin (SST) is reported across chronic brain conditions including major depression and normal aging. SST is a signaling neuropeptide and marker of gamma-amino butyric acid (GABA) neurons, which specifically inhibit pyramidal neuron dendrites. Studies in auditory cortex suggest that chronic reduction in dendritic inhibition induces compensatory homeostatic adaptations that oppose the effects of acute inhibition. Whether such mechanisms occur in frontal cortex (FC) and affect behavioral outcome is not known. Here, we used two complementary viral vector strategies to examine the effects of acute vs chronic inhibition of SST-positive neurons on behavioral emotionality in adult mice. SST-IRES-Cre mice were injected in FC (prelimbic/precingulate) with CRE-dependent adeno-associated viral (AAV) vector encoding the engineered Gi/o-coupled human muscarinic M4 designer receptor exclusively activated by a designer drug (DREADD-hM4Di) or a control reporter (AAV-DIO-mCherry) for acute or chronic cellular inhibition. A separate cohort was injected with CRE-dependent AAV vectors expressing diphtheria toxin (DTA) to selectively ablate FC SST neurons. Mice were assessed for anxiety- and depressive-like behaviors (defined as emotionality). Results indicate that acute inhibition of FC SST neurons increased behavioral emotionality, whereas chronic inhibition decreased behavioral emotionality. Furthermore, ablation of FC SST neurons also decreased behavioral emotionality under baseline condition and after chronic stress. Together, our results reveal opposite effects of acute and chronic inhibition of FC SST neurons on behavioral emotionality and suggest the recruitment of homeostatic plasticity mechanisms that have implications for understanding the neurobiology of chronic brain conditions affecting dendritic-targeting inhibitory neurons.

A spurious warming trend in the NMME equatorial Pacific SST hindcasts

NASA Astrophysics Data System (ADS)

Shin, Chul-Su; Huang, Bohua

2017-06-01

Using seasonal hindcasts of six different models participating in the North American Multimodel Ensemble project, the trend of the predicted sea surface temperature (SST) in the tropical Pacific for 1982-2014 at each lead month and its temporal evolution with respect to the lead month are investigated for all individual models. Since the coupled models are initialized with the observed ocean, atmosphere, land states from observation-based reanalysis, some of them using their own data assimilation process, one would expect that the observed SST trend is reasonably well captured in their seasonal predictions. However, although the observed SST features a weak-cooling trend for the 33-year period with La Niña-like spatial pattern in the tropical central-eastern Pacific all year round, it is demonstrated that all models having a time-dependent realistic concentration of greenhouse gases (GHG) display a warming trend in the equatorial Pacific that amplifies as the lead-time increases. In addition, these models' behaviors are nearly independent of the starting month of the hindcasts although the growth rates of the trend vary with the lead month. This key characteristic of the forecasted SST trend in the equatorial Pacific is also identified in the NCAR CCSM3 hindcasts that have the GHG concentration for a fixed year. This suggests that a global warming forcing may not play a significant role in generating the spurious warming trend of the coupled models' SST hindcasts in the tropical Pacific. This model SST trend in the tropical central-eastern Pacific, which is opposite to the observed one, causes a developing El Niño-like warming bias in the forecasted SST with its peak in boreal winter. Its implications for seasonal prediction are discussed.

The absence of an Atlantic imprint on the multidecadal variability of wintertime European temperature.

PubMed

Yamamoto, Ayako; Palter, Jaime B

2016-03-15

Northern Hemisphere climate responds sensitively to multidecadal variability in North Atlantic sea surface temperature (SST). It is therefore surprising that an imprint of such variability is conspicuously absent in wintertime western European temperature, despite that Europe's climate is strongly influenced by its neighbouring ocean, where multidecadal variability in basin-average SST persists in all seasons. Here we trace the cause of this missing imprint to a dynamic anomaly of the atmospheric circulation that masks its thermodynamic response to SST anomalies. Specifically, differences in the pathways Lagrangian particles take to Europe during anomalous SST winters suppress the expected fluctuations in air-sea heat exchange accumulated along those trajectories. Because decadal variability in North Atlantic-average SST may be driven partly by the Atlantic Meridional Overturning Circulation (AMOC), the atmosphere's dynamical adjustment to this mode of variability may have important implications for the European wintertime temperature response to a projected twenty-first century AMOC decline.

Estimating Sea Surface Temperature Measurement Methods Using Characteristic Differences in the Diurnal Cycle

NASA Astrophysics Data System (ADS)

Carella, G.; Kennedy, J. J.; Berry, D. I.; Hirahara, S.; Merchant, C. J.; Morak-Bozzo, S.; Kent, E. C.

2018-01-01

Lack of reliable observational metadata represents a key barrier to understanding sea surface temperature (SST) measurement biases, a large contributor to uncertainty in the global surface record. We present a method to identify SST measurement practice by comparing the observed SST diurnal cycle from individual ships with a reference from drifting buoys under similar conditions of wind and solar radiation. Compared to existing estimates, we found a larger number of engine room-intake (ERI) reports post-World War II and in the period 1960-1980. Differences in the inferred mixture of observations lead to a systematic warmer shift of the bias adjusted SST anomalies from 1980 compared to previous estimates, while reducing the ensemble spread. Changes in mean field differences between bucket and ERI SST anomalies in the Northern Hemisphere over the period 1955-1995 could be as large as 0.5°C and are not well reproduced by current bias adjustment models.

Tropical cyclone rainfall area controlled by relative sea surface temperature

PubMed Central

Lin, Yanluan; Zhao, Ming; Zhang, Minghua

2015-01-01

Tropical cyclone rainfall rates have been projected to increase in a warmer climate. The area coverage of tropical cyclones influences their impact on human lives, yet little is known about how tropical cyclone rainfall area will change in the future. Here, using satellite data and global atmospheric model simulations, we show that tropical cyclone rainfall area is controlled primarily by its environmental sea surface temperature (SST) relative to the tropical mean SST (that is, the relative SST), while rainfall rate increases with increasing absolute SST. Our result is consistent with previous numerical simulations that indicated tight relationships between tropical cyclone size and mid-tropospheric relative humidity. Global statistics of tropical cyclone rainfall area are not expected to change markedly under a warmer climate provided that SST change is relatively uniform, implying that increases in total rainfall will be confined to similar size domains with higher rainfall rates. PMID:25761457

Estimation of sea surface temperature from remote sensing in the 11-13 micron window region

NASA Technical Reports Server (NTRS)

Prabhakara, C.; Dalu, G.; Kunde, V. G.

1974-01-01

The Nimbus 3 and 4 IRIS spectral data in the 11-13 micron water vapor window region are analyzed to determine the sea surface temperature (SST). The high spectral resolution data of IRIS are averaged over approximately 1 micron wide intervals to simulate channels of a radiometer to measure the SST. Three channels are utilized to measure SST over cloud-free oceans. However, two of these channels are sufficient in routine SST determination. The differential absorption properties of water vapor in the two channels enable one to determine the water vapor absorption correction without detailed knowledge of the vertical profiles of temperature and water vapor. The feasibility of determining the SST is demonstrated globally with Nimbus 3 data where cloud-free areas can be selected with the help of albedo data from the MRIR experiment on board the same satellite.

Sea surface temperature anomalies, planetary waves, and air-sea feedback in the middle latitudes

NASA Technical Reports Server (NTRS)

Frankignoul, C.

1985-01-01

Current analytical models for large-scale air-sea interactions in the middle latitudes are reviewed in terms of known sea-surface temperature (SST) anomalies. The scales and strength of different atmospheric forcing mechanisms are discussed, along with the damping and feedback processes controlling the evolution of the SST. Difficulties with effective SST modeling are described in terms of the techniques and results of case studies, numerical simulations of mixed-layer variability and statistical modeling. The relationship between SST and diabatic heating anomalies is considered and a linear model is developed for the response of the stationary atmosphere to the air-sea feedback. The results obtained with linear wave models are compared with the linear model results. Finally, sample data are presented from experiments with general circulation models into which specific SST anomaly data for the middle latitudes were introduced.

Appraising timing response of paleoenvironmental proxies to the Bond cycle in the western Mediterranean over the last 20 kyr

NASA Astrophysics Data System (ADS)

Rodrigo-Gámiz, Marta; Martínez-Ruiz, Francisca; Rodríguez-Tovar, Francisco J.; Pardo-Igúzquiza, Eulogio; Ortega-Huertas, Miguel

2018-04-01

The timing of climate responses to the Bond cycle is investigated in the western Mediterranean. Periodicities had been previously reported in a marine sediment record from this region spanning the last 20 kyr, and registered by diverse paleoenvironmental proxies, in particular those associated with terrigenous input, redox conditions, productivity, sea surface temperature (SST) and salinity. Further cross-spectral analyses on these time series reveal leads-lags in the 1400 year climate cycle. Considering as reference a terrigenous input proxy (the K/Al ratio), all the paleoenvironmental proxies displayed time shifts varying from ca. 700 year to ca. 350 year. SST and salinity variations show a first leaded response with the inflow of cold and less salty Atlantic waters. Followed by a time lead of 525 year, progresively arid conditions with an increase of eolian dust transport to the area, given by the Zr/Al signal, are observed. The intensification of dust transport could have triggered a latest biological response, lead by 350 year, with an increase of productivity, as suggested by the Ba/Al ratio. Lastly changes in the Mediterranean thermohaline circulation, indicated by a selected redox proxy (the U/Th ratio), are observed. These results support that the oceanic response triggered the atmospheric response to the Bond cycle in the western Mediterranean. Changes in the North Atlantic Oscillation mode and in the Inter-Tropical Convergence Zone migrations with variations in the monsoon activity or Saharan winds system, are considered as main forcing mechanisms, with a complex relationship of the involved phenomena.

Further Studies on Oceanic Biogeochemistry and Carbon Cycling

NASA Technical Reports Server (NTRS)

Signorini, S. R.; McClain, C. R.

2003-01-01

This TM consists of two chapters. Chapter I describes the development of a coupled, one-dimensional biogeochemical model using turbulence closure mixed layer (TCMLM) dynamics. The model is applied to the Sargasso Sea at the BATS (Bermuda Atlantic Time Series) site and the results are compared with a previous model study in the same region described in NASNTP-2001-209991. The use of the TCMLM contributed to some improvements in the model simulation of chlorophyll, PAR, nitrate, phosphate, and oxygen, but most importantly, the current model achieved good agreement with the data with much more realistic background eddy diffusivity. However, off-line calculations of horizontal transport of biogeochemical properties revealed that one-dimensional dynamics can only provide a limited assessment of the nutrient and carbon balances at BATS. Future studies in the BATS region will require comprehensive three-dimensional field studies, combined with three-dimensional eddy resolving numerical experiments, to adequately quantify the impact of the local and remote forcing on ecosystem dynamics and carbon cycling. Chapter II addresses the sensitivity of global sea-air CO, flux estimates to wind speed, temperature, and salinity. Sensitivity analyses of sea-air CO, flux to wind speed climatologies, gas transfer algorithms, SSS and SST were conducted for the global oceans and regional domains. Large uncertainties in the global sea-air flux are identified, primarily due to the different gas transfer algorithms used. The sensitivity of the sea-air flux to SST and SSS is similar in magnitude to the effect of using different wind climatologies. Globally, the mean ocean uptake of CO, changes by 5 to 16%, depending upon the combination of SST and SSS used.

Climatic teleconnections between the subtropical and polar North Atlantic during the Last Interglacial period (MIS5e)

NASA Astrophysics Data System (ADS)

Bauch, H. A.; Zhuravleva, A.

2017-12-01

Meridional gradients in sea surface temperature (SST) control ocean-atmosphere circulation patterns and, thus, regulate the global climate. Here we reconstruct variability of these gradients in the course of the Last Interglacial (MIS5e), by using sediment records from the low and high latitude North Atlantic which are linked via the Gulf Stream.In the Nordic Seas, i.e., at the northern end of the Gulf Stream extension, strong post-Saalian meltwater discharge reduced northward-directed transport of surface oceanic heat until the mid-MIS5e, resulting in a late and rather weak SST peak. To decipher the corresponding climatic changes in the area of the Gulf Stream origin, we employ stable isotopes data, planktic foraminifera assemblages as well as a new alkenone paleotemperature record from core drilled on the upper northern slope of the Little Bahama Bank. In addition, chemical composition of sediments (XRF data) was used to asses past sea level fluctuations and sedimentation regimes on this shallow-water carbonate bank. Significant variations in Sr/Ca ratios point to a two-fold structure of the Last Interglacial. Stabilized Sr/Ca values were reached only during the second phase of MIS5e, possibly representing the interval of maximum bank-top flooding after the northern hemisphere deglaciation terminated. Faunal-based proxies as well as oxygen isotopic gradients between surface and bottom-dwelling foraminifera corroborate existence of the two major climatic phases within the Last Interglacial, in agreement with the respective development in the polar region. This further suggests a strong climatic coupling between the subtropical and high-latitude North Atlantic with important implications for meridional SST gradients during the Last Interglacial.

Patterns of interannual climate variability in large marine ecosystems

NASA Astrophysics Data System (ADS)

Soares, Helena Cachanhuk; Gherardi, Douglas Francisco Marcolino; Pezzi, Luciano Ponzi; Kayano, Mary Toshie; Paes, Eduardo Tavares

2014-06-01

The purpose of this study is to investigate the vulnerability of the Brazilian and western African Large Marine Ecosystems (LMEs) to local and remote forcing, including the Pacific Decadal Oscillation (PDO) regime shift. The analyses are based on the total and partial correlation between climate indices (Niño3, tropical South Atlantic (TSA), tropical North Atlantic (TNA) and Antarctic oscillation (AAO) and oceanic and atmospheric variables (sea surface temperature (SST), wind stress, Ekman transport, sea level pressure and outgoing longwave radiation). Differences in the correlation fields between the cold and warm PDO indicate that this mode exerts a significant impact on the thermodynamic balance of the ocean-atmosphere system on the South Atlantic ocean, mainly in the South Brazil and Benguela LMEs. The PDO regime shift also resulted in an increase in the spatial variability of SST and wind stress anomalies, mainly along the western African LMEs. Another important finding is the strong AAO influence on the SST anomalies (SSTA) in the South Brazil LME. It is also striking that TSA modulates the relation between El Niño-Southern Oscillation (ENSO) and SSTA, by reducing the influence of ENSO on SSTA during the warm PDO period in the North and East Brazil LMEs and in the Guinea Current LME. The relation between AAO and SSTA on the tropical area is also influenced by the TSA. The results shown here give a clear indication that future ecosystem-based management actions aimed at the conservation of marine resources under climate change need to consider the high complexity of basin-scale interactions between local and remote climate forcings, including their effects on the ocean-atmosphere system of the South Atlantic ocean.

Error Estimation in an Optimal Interpolation Scheme for High Spatial and Temporal Resolution SST Analyses

NASA Technical Reports Server (NTRS)

Rigney, Matt; Jedlovec, Gary; LaFontaine, Frank; Shafer, Jaclyn

2010-01-01

Heat and moisture exchange between ocean surface and atmosphere plays an integral role in short-term, regional NWP. Current SST products lack both spatial and temporal resolution to accurately capture small-scale features that affect heat and moisture flux. NASA satellite is used to produce high spatial and temporal resolution SST analysis using an OI technique.

Spherical harmonic expansion of the Levitus Sea surface topography

NASA Technical Reports Server (NTRS)

Engelis, Theodossios

1987-01-01

Prior information for the stationary sea surface topography (SST) may be needed in altimetric solutions that intend to simultaneously improve the gravity field and determine the SST. For this purpose the oceanographically derived SST estimates are represented by a spherical harmonic expansion. The spherical harmonic coefficients are computed from a least squares adjustment of the data covering the majority of the oceanic regions of the world. Several tests are made to determine the optimum maximum degree of solution and the best configuration of the geometry of the data in order to obtain a solution that fits the data and also provides a good spectral representation of the SST.

Interleukin-33/ST2 system attenuates aldosterone-induced adipogenesis and inflammation.

PubMed

Martínez-Martínez, Ernesto; Cachofeiro, Victoria; Rousseau, Elodie; Álvarez, Virginia; Calvier, Laurent; Fernández-Celis, Amaya; Leroy, Céline; Miana, María; Jurado-López, Raquel; Briones, Ana M; Jaisser, Frederic; Zannad, Faiez; Rossignol, Patrick; López-Andrés, Natalia

2015-08-15

Interleukin-33 (IL-33) but not soluble ST2 (sST2) exerts anti-inflammatory and protective effects in several tissues. Aldosterone, a proinflammatory mediator which promotes adipogenesis, is elevated in obese patients. The aim of this study was to investigate the interactions between IL-33/ST2 system and Aldosterone in adipose tissue. Rats fed a high fat diet presented increased sST2 expression, diminished IL-33/sST2 ratio and enhanced levels of differentiation and inflammation in adipose tissue as compared to controls. A similar pattern was observed in adipose tissue from C57BL/6 Aldosterone-treated mice. In both animal models, Aldosterone was correlated with sST2. Treatment of 3T3-L1 adipocytes with IL-33 delayed adipocyte differentiation diminished lipid accumulation and decreased inflammation. Aldosterone decreased IL-33 and increased sST2 expressions in differentiated adipocytes. Aldosterone-induced adipocyte differentiation and inflammation were blocked by IL-33 treatment, but sST2 did not exert any effects. The crosstalk between IL-33/ST2 and Aldosterone could be relevant in the metabolic consequences of obesity. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Analyzing the Effects of Climate Change on Sea Surface Temperature in Monitoring Coral Reef Health in the Florida Keys Using Sea Surface Temperature Data

NASA Technical Reports Server (NTRS)

Jones, Jason; Burbank, Renane; Billiot, Amanda; Schultz, Logan

2011-01-01

This presentation discusses use of 4 kilometer satellite-based sea surface temperature (SST) data to monitor and assess coral reef areas of the Florida Keys. There are growing concerns about the impacts of climate change on coral reef systems throughout the world. Satellite remote sensing technology is being used for monitoring coral reef areas with the goal of understanding the climatic and oceanic changes that can lead to coral bleaching events. Elevated SST is a well-documented cause of coral bleaching events. Some coral monitoring studies have used 50 km data from the Advanced Very High Resolution Radiometer (AVHRR) to study the relationships of sea surface temperature anomalies to bleaching events. In partnership with NOAA's Office of National Marine Sanctuaries and the University of South Florida's Institute for Marine Remote Sensing, this project utilized higher resolution SST data from the Terra's Moderate Resolution Imaging Spectroradiometer (MODIS) and AVHRR. SST data for 2000-2010 was employed to compute sea surface temperature anomalies within the study area. The 4 km SST anomaly products enabled visualization of SST levels for known coral bleaching events from 2000-2010.

Sensitivity of Offshore Surface Fluxes and Sea Breezes to the Spatial Distribution of Sea-Surface Temperature

NASA Astrophysics Data System (ADS)

Lombardo, Kelly; Sinsky, Eric; Edson, James; Whitney, Michael M.; Jia, Yan

2018-03-01

A series of numerical sensitivity experiments is performed to quantify the impact of sea-surface temperature (SST) distribution on offshore surface fluxes and simulated sea-breeze dynamics. The SST simulations of two mid-latitude sea-breeze events over coastal New England are performed using a spatially-uniform SST, as well as spatially-varying SST datasets of 32- and 1-km horizontal resolutions. Offshore surface heat and buoyancy fluxes vary in response to the SST distribution. Local sea-breeze circulations are relatively insensitive, with minimal differences in vertical structure and propagation speed among the experiments. The largest thermal perturbations are confined to the lowest 10% of the sea-breeze column due to the relatively high stability of the mid-Atlantic marine atmospheric boundary layer (ABL) suppressing vertical mixing, resulting in the depth of the marine layer remaining unchanged. Minimal impacts on the column-averaged virtual potential temperature and sea-breeze depth translates to small changes in sea-breeze propagation speed. This indicates that the use of datasets with a fine-scale SST may not produce more accurate sea-breeze simulations in highly stable marine ABL regimes, though may prove more beneficial in less stable sub-tropical environments.

Assessing the applicability of organic SST proxies in an upwelling region (Arabian Sea)

NASA Astrophysics Data System (ADS)

Lattaud, J.; van Erk, M. R.; Reichart, G. J.; Schulz, H.; S Sinninghe Damsté, J.; Schouten, S.

2017-12-01

Multiple organic proxies have the potential to reconstruct sea surface temperature (SST), but their behaviour is not completely understood within upwelling areas. This holds in particular for the recently developed Long chain Diol Index1 (LDI), based on the ratio of 1,15-diols over 1,13-diols, both likely produced by Eustigmatophytes. We tested the applicability of the LDI by comparing it to the more established temperature proxies TEX86 and Uk¢37 in a sediment core (spanning the last 76 ky) from the northern Arabian Sea and in surface sediments (Pakistan margin). In the surface sediments, Uk¢37- and LDI-SSTs agree well with annual mean SST, but the TEX86-SST substantially overestimates SST. A better agreement is observed, when the 0-200 m TEX86 calibration is used, suggesting TEX86 reflects subsurface temperatures. The results from the sediment core reveal that the SST records differ in absolute reconstructed temperature and show different patterns. TEX86 subsurface temperatures show a continuous increase toward the Holocene and no stadial/interstadial differences, while the LDI-SST is constant around 26°C with the exception of some short-term cooling events during periods of intensified upwelling. The Uk¢37-SST varies between 22 and 26°C and follows the global δ18Obenthic foram curve and thus is representing mean annual SST in this region3. During stadials, the reduced monsoon and low upwelling intensity resulted in warming of the subsurface waters2, as indicated by higher TEX86 temperatures, while global cooling led to colder surface waters as reflected in lower Uk¢37-SSTs, thus reducing the thermal gradient in the water column2. During the interstadials, which are periods of strong upwelling3, there is a high proportion of 1,14-diols (>40%). This probably disturbs the LDI-SST signal because the diatoms that produce the 1,14-diols are also generating small amounts of the 1,13-diols4. This suggests that care has to be taken in applying the LDI in upwelling regions. References 1Rampen et al., 2012 2Tierney et al., 2015 3Emeis et al., 1995 4Rampen et al., 2007

Role of Soluble ST2 Levels and Beta-Blockers Dosage on Cardiovascular Events of Patients with Unselected ST-Segment Elevation Myocardial Infarction

PubMed Central

Huang, Wei-Ping; Zheng, Xuan; He, Lei; Su, Xi; Liu, Cheng-Wei; Wu, Ming-Xiang

2018-01-01

Background: Serum soluble ST2 (sST2) levels are elevated early after acute myocardial infarction and are related to adverse left ventricular (LV) remodeling and cardiovascular outcomes in ST-segment elevation myocardial infarction (STEMI). Beta-blockers (BB) have been shown to improve LV remodeling and survival. However, the relationship between sST2, final therapeutic BB dose, and cardiovascular outcomes in STEMI patients remains unknown. Methods: A total of 186 STEMI patients were enrolled at the Wuhan Asia Heart Hospital between January 2015 and June 2015. All patients received standard treatment and were followed up for 1 year. Serum sST2 was measured at baseline. Patients were divided into four groups according to their baseline sST2 values (high >56 ng/ml vs. low ≤56 ng/ml) and final therapeutic BB dose (high ≥47.5 mg/d vs. low <47.5 mg/d). Cox regression analyses were performed to determine whether sST2 and BB were independent risk factors for cardiovascular events in STEMI. Results: Baseline sST2 levels were positively correlated with heart rate (r = 0.327, P = 0.002), Killip class (r = 0.408, P = 0.000), lg N-terminal prohormone B-type natriuretic peptide (r = 0.467, P = 0.000), lg troponin I (r = 0.331, P = 0.000), and lg C-reactive protein (r = 0.307, P = 0.000) and negatively correlated to systolic blood pressure (r = −0.243, P = 0.009) and LV ejection fraction (r = −0.402, P = 0.000). Patients with higher baseline sST2 concentrations who were not titrated to high-dose BB therapy (P < 0.0001) had worse outcomes. Baseline high sST2 (hazard ratio [HR]: 2.653; 95% confidence interval [CI]: 1.201–8.929; P = 0.041) and final low BB dosage (HR: 1.904; 95% CI, 1.084–3.053; P = 0.035) were independent predictors of cardiovascular events in STEMI. Conclusions: High baseline sST2 levels and final low BB dosage predicted cardiovascular events in STEMI. Hence, sST2 may be a useful biomarker in cardiac pathophysiology. PMID:29786039

Impact of SST on heavy rainfall events on eastern Adriatic during SOP1 of HyMeX

NASA Astrophysics Data System (ADS)

Ivatek-Šahdan, Stjepan; Stanešić, Antonio; Tudor, Martina; Odak Plenković, Iris; Janeković, Ivica

2018-02-01

The season of late summer and autumn is favourable for intensive precipitation events (IPE) in the central Mediterranean. During that period the sea surface is warm and contributes to warming and moistening of the lowest portion of the atmosphere, particularly the planetary boundary layer (PBL). Adriatic sea is surrounded by mountains and the area often receives substantial amounts of precipitation in short time (24 h). The IPEs are a consequence of convection triggered by topography acting on the southerly flow that has brought the unstable air to the coastline. Improvement in prediction of high impact weather events is one of the goals of The Hydrological cycle in the Mediterranean eXperiment (HyMeX). This study examines how precipitation patterns change in response to different SST forcing. We focus on the IPEs that occurred on the eastern Adriatic coast during the first HyMeX Special observing period (SOP1, 6 September to 5 November 2012). The operational forecast model ALADIN uses the same SST as the global meteorological model (ARPEGE from Meteo France), as well as the forecast lateral boundary conditions (LBCs). First we assess the SST used by the operational atmospheric model ALADIN and compare it to the in situ measurements, ROMS ocean model, OSTIA and MUR analyses. Results of this assessment show that SST in the eastern Adriatic was overestimated by up to 10 K during HyMeX SOP1 period. Then we examine the sensitivity of 8 km and 2 km resolution forecasts of IPEs to the changes in the SST during whole SOP1 with special attention to the intensive precipitation event in Rijeka. Forecast runs in both resolutions are performed for the whole SOP1 using different SST fields prescribed at initial time and kept constant during the model forecast. Categorical verification of 24 h accumulated precipitation did not show substantial improvement in verification scores when more realistic SST was used. Furthermore, the results show that the impact of introducing improved SST in the analysis on the precipitation forecast varies for different cases. There is generally a larger sensitivity to the SST in high resolution than in the lower one, although the forecast period of the latter is longer.

The influence of sea surface temperature on the intensity and associated storm surge of tropical cyclone Yasi: a sensitivity study

NASA Astrophysics Data System (ADS)

Lavender, Sally L.; Hoeke, Ron K.; Abbs, Deborah J.

2018-03-01

Tropical cyclones (TCs) result in widespread damage associated with strong winds, heavy rainfall and storm surge. TC Yasi was one of the most powerful TCs to impact the Queensland coast since records began. Prior to Yasi, the SSTs in the Coral Sea were higher than average by 1-2 °C, primarily due to the 2010/2011 La Niña event. In this study, a conceptually simple idealised sensitivity analysis is performed using a high-resolution regional model to gain insight into the influence of SST on the track, size, intensity and associated rainfall of TC Yasi. A set of nine simulations with uniform SST anomalies of between -4 and 4 °C applied to the observed SSTs are analysed. The resulting surface winds and pressure are used to force a barotropic storm surge model to examine the influence of SST on the associated storm surge of TC Yasi. An increase in SST results in an increase in intensity, precipitation and integrated kinetic energy of the storm; however, there is little influence on track prior to landfall. In addition to an increase in precipitation, there is a change in the spatial distribution of precipitation as the SST increases. Decreases in SSTs result in an increase in the radius of maximum winds due to an increase in the asymmetry of the storm, although the radius of gale-force winds decreases. These changes in the TC characteristics also lead to changes in the associated storm surge. Generally, cooler (warmer) SSTs lead to reduced (enhanced) maximum storm surges. However, the increase in surge reaches a maximum with an increase in SST of 2 °C. Any further increase in SST does not affect the maximum surge but the total area and duration of the simulated surge increases with increasing upper ocean temperatures. A large decrease in maximum storm surge height occurs when a negative SST anomaly is applied, suggesting if TC Yasi had occurred during non-La Niña conditions the associated storm surge may have been greatly diminished, with a decrease in storm surge height of over 3 m when the SST is reduced by 2 °C. In summary, increases in SST lead to an increase in the potential destructiveness of TCs with regard to intensity, precipitation and storm surge, although this relationship is not linear.

Sho-saiko-to, a traditional herbal medicine, regulates gene expression and biological function by way of microRNAs in primary mouse hepatocytes

PubMed Central

2014-01-01

Background Sho-saiko-to (SST) (also known as so-shi-ho-tang or xiao-chai-hu-tang) has been widely prescribed for chronic liver diseases in traditional Oriental medicine. Despite the substantial amount of clinical evidence for SST, its molecular mechanism has not been clearly identified at a genome-wide level. Methods By using a microarray, we analyzed the temporal changes of messenger RNA (mRNA) and microRNA expression in primary mouse hepatocytes after SST treatment. The pattern of genes regulated by SST was identified by using time-series microarray analysis. The biological function of genes was measured by pathway analysis. For the identification of the exact targets of the microRNAs, a permutation-based correlation method was implemented in which the temporal expression of mRNAs and microRNAs were integrated. The similarity of the promoter structure between temporally regulated genes was measured by analyzing the transcription factor binding sites in the promoter region. Results The SST-regulated gene expression had two major patterns: (1) a temporally up-regulated pattern (463 genes) and (2) a temporally down-regulated pattern (177 genes). The integration of the genes and microRNA demonstrated that 155 genes could be the targets of microRNAs from the temporally up-regulated pattern and 19 genes could be the targets of microRNAs from the temporally down-regulated pattern. The temporally up-regulated pattern by SST was associated with signaling pathways such as the cell cycle pathway, whereas the temporally down-regulated pattern included drug metabolism-related pathways and immune-related pathways. All these pathways could be possibly associated with liver regenerative activity of SST. Genes targeted by microRNA were moreover associated with different biological pathways from the genes not targeted by microRNA. An analysis of promoter similarity indicated that co-expressed genes after SST treatment were clustered into subgroups, depending on the temporal expression patterns. Conclusions We are the first to identify that SST regulates temporal gene expression by way of microRNA. MicroRNA targets and non-microRNA targets moreover have different biological roles. This functional segregation by microRNA would be critical for the elucidation of the molecular activities of SST. PMID:24410935

Sho-saiko-to, a traditional herbal medicine, regulates gene expression and biological function by way of microRNAs in primary mouse hepatocytes.

PubMed

Song, Kwang Hoon; Kim, Yun Hee; Kim, Bu-Yeo

2014-01-11

Sho-saiko-to (SST) (also known as so-shi-ho-tang or xiao-chai-hu-tang) has been widely prescribed for chronic liver diseases in traditional Oriental medicine. Despite the substantial amount of clinical evidence for SST, its molecular mechanism has not been clearly identified at a genome-wide level. By using a microarray, we analyzed the temporal changes of messenger RNA (mRNA) and microRNA expression in primary mouse hepatocytes after SST treatment. The pattern of genes regulated by SST was identified by using time-series microarray analysis. The biological function of genes was measured by pathway analysis. For the identification of the exact targets of the microRNAs, a permutation-based correlation method was implemented in which the temporal expression of mRNAs and microRNAs were integrated. The similarity of the promoter structure between temporally regulated genes was measured by analyzing the transcription factor binding sites in the promoter region. The SST-regulated gene expression had two major patterns: (1) a temporally up-regulated pattern (463 genes) and (2) a temporally down-regulated pattern (177 genes). The integration of the genes and microRNA demonstrated that 155 genes could be the targets of microRNAs from the temporally up-regulated pattern and 19 genes could be the targets of microRNAs from the temporally down-regulated pattern. The temporally up-regulated pattern by SST was associated with signaling pathways such as the cell cycle pathway, whereas the temporally down-regulated pattern included drug metabolism-related pathways and immune-related pathways. All these pathways could be possibly associated with liver regenerative activity of SST. Genes targeted by microRNA were moreover associated with different biological pathways from the genes not targeted by microRNA. An analysis of promoter similarity indicated that co-expressed genes after SST treatment were clustered into subgroups, depending on the temporal expression patterns. We are the first to identify that SST regulates temporal gene expression by way of microRNA. MicroRNA targets and non-microRNA targets moreover have different biological roles. This functional segregation by microRNA would be critical for the elucidation of the molecular activities of SST.

Characterizing surface temperature and clarity of Kuwait's seawaters using remotely sensed measurements and GIS analyses

NASA Astrophysics Data System (ADS)

Alsahli, Mohammad M. M.

Kuwait sea surface temperature (SST) and water clarity are important water characteristics that influence the entire Kuwait coastal ecosystem. The spatial and temporal distributions of these important water characteristics should be well understood to obtain a better knowledge about this productive coastal environment. The aim of this project was therefore to study the spatial and temporal distributions of: Kuwait SST using Moderate Resolution Imaging Spectroradiometer (MODIS) images collected from January 2003 to July 2007; and Kuwait Secchi Disk Depth (SDD), a water clarity measure, using Sea-viewing Wide Field-of-view Sensor (SeaWiFS) and MODIS data collected from November 1998 to October 2004 and January 2003 to June 2007, respectively. Kuwait SST was modeled based on the linear relationship between level 2 MODIS SST data and in situ SST data. MODIS SST images showed a significant relationship with in situ SST data ( r2= 0.98, n = 118, RMSE = 0.7°C). Kuwait SST images derived from MODIS data exhibited three spatial patterns of Kuwait SST across the year that were mainly attributed to the northwestern counterclockwise water circulation of the Arabian Gulf, and wind direction and intensity. The temporal variation of Kuwait SST was greatly influenced by the seasonal variation of solar intensity and air temperatures. Kuwait SDD was measured through two steps: first, computing the diffuse light attenuation coefficient at 490 nm, Kd(490), and 488 nm, Kd(488), derived from SeaWiFS and MODIS, respectively, using a semi-analytical algorithm; second, establishing two SDD models based on the empirical relationship of Kd(490) and Kd(488) with in situ SDD data. Kd(490) and Kd(488) showed a significant relationship with in situ SDD data ( r2= 0.67 and r2= 0.68, respectively). Kuwait SDD images showed distinct spatial and temporal patterns of Kuwait water clarity that were mainly attributed to three factors: the Shatt Al-Arab discharge, water circulation, and coastal currents. The SeaWiFS and MODIS data compared to in situ measurements provided a comprehensive view of the studied seawater characteristics that improved their overall estimation within Kuwait's waters. Also, the near-real-time availability of SeaWiFS and MODIS data and their highly temporal resolution make them a very advantageous tool for studying coastal environments. Thus, I recommend involving this method in monitoring Kuwait coastal environments.

Climate change and larval transport in the ocean: fractional effects from physical and physiological factors.

PubMed

Kendall, Matthew S; Poti, Matt; Karnauskas, Kristopher B

2016-04-01

Changes in larval import, export, and self-seeding will affect the resilience of coral reef ecosystems. Climate change will alter the ocean currents that transport larvae and also increase sea surface temperatures (SST), hastening development, and shortening larval durations. Here, we use transport simulations to estimate future larval connectivity due to: (1) physical transport of larvae from altered circulation alone, and (2) the combined effects of altered currents plus physiological response to warming. Virtual larvae from islands throughout Micronesia were moved according to present-day and future ocean circulation models. The Hybrid Coordinate Ocean Model (HYCOM) spanning 2004-2012 represented present-day currents. For future currents, we altered HYCOM using analysis from the National Center for Atmospheric Research Community Earth System Model, version 1-Biogeochemistry, Representative Concentration Pathway 8.5 experiment. Based on the NCAR model, regional SST is estimated to rise 2.74 °C which corresponds to a ~17% decline in larval duration for some taxa. This reduction was the basis for a separate set of simulations. Results predict an increase in self-seeding in 100 years such that 62-76% of islands experienced increased self-seeding, there was an average domainwide increase of ~1-3% points in self-seeding, and increases of up to 25% points for several individual islands. When changed currents alone were considered, approximately half (i.e., random) of all island pairs experienced decreased connectivity but when reduced PLD was added as an effect, ~65% of connections were weakened. Orientation of archipelagos relative to currents determined the directional bias in connectivity changes. There was no universal relationship between climate change and connectivity applicable to all taxa and settings. Islands that presently export large numbers of larvae but that also maintain or enhance this role into the future should be the focus of conservation measures that promote long-term resilience of larval supply. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Investigation of different coastal processes in Indonesian waters using SeaWiFS data

NASA Astrophysics Data System (ADS)

Hendiarti, Nani; Siegel, Herbert; Ohde, Thomas

2004-01-01

SeaWiFS data were applied to investigate coastal processes in Indonesian waters around the most populated island of Java. Coastal processes due to wind forcing were studied the first time using SeaWiFS-derived chlorophyll and TSM concentrations in combination with AVHRR-derived SST in the period from September 1997 to December 2001. Upwelling events were studied along the southern coast of Java during the southeast monsoon (June to September). Satellite-derived chlorophyll concentrations higher than 0.8 mg/ m3 and sea-surface temperatures lower than 28°C are indications of upwelling. Upwelling events influence the distribution and growth of phytoplankton and provide by that good feeding condition for zooplankton, larvae, juvenile and adult of pelagic fish. Coastal discharge into the western Java Sea contains organic and inorganic materials originating from different sources. Diffuse impacts, particularly from fish farms and aquaculture, as well as coastal erosion influence large coastal areas during the rainy season (December to March), and to a lesser extent during the dry season. Strong Citarum river discharge was observed during the transition phase from the rainy to the dry season (March and April), when the maximum amount of transported material reaches the sea. The river plume is evident from chlorophyll concentrations higher than 2.5 mg/ m3, and suspended particulate matter concentrations of more than 8 mg/dm3. The Sunda Strait is seasonally influenced by water transport from the Java Sea and from the Indian Ocean. The satellite data show that water transport from the Java Sea occurs during the pre-dominantly easterly winds period (June to September). This is characterized by warm water (SST higher than 29.5°C) and chlorophyll concentrations higher than 0.5 mg/ m3. This water transport influences the fish abundance in the Sunda Strait. High fish catches coincide with the presence of Java Sea water, while the surface currents lead to the migration of pelagic fish. Conversely, during the dominant westerly winds period, oceanic waters from the Indian Ocean with low chlorophyll concentrations influence the Sunda Strait water.

ESA activities on satellite laser ranging to non-cooperative objects

NASA Astrophysics Data System (ADS)

Flohrer, Tim; Krag, Holger; Funke, Quirin; Jilete, Beatriz; Mancas, Alexandru

2016-07-01

Satellite laser ranging (SLR) to non-cooperative objects is an emerging technology that can contribute significantly to operational, modelling and mitigation needs set by the space debris population. ESA is conducting various research and development activities in SLR to non-cooperative objects. ESA's Space Situational Awareness (SSA) program supports specific activities in the Space Surveillance and Tracking (SST) segment. Research and development activities with operational aspects are run by ESA's Space Debris Office. At ESA SSA/SST comprises detecting, cataloguing and predicting the objects orbiting the Earth, and the derived applications. SST aims at facilitating research and development of sensor and data processing technologies and of related common components while staying complementary with, and in support of, national and multi-national European initiatives. SST promotes standardisation and interoperability of the technology developments. For SLR these goals are implemented through researching, developing, and deploying an expert centre. This centre shall coordinate the contribution of system-external loosely connected SLR sensors, and shall provide back calibration and expert evaluation support to the sensors. The Space Debris Office at ESA is responsible for all aspects related to space debris in the Agency. It is in charge of providing operational support to ESA and third party missions. Currently, the office studies the potential benefits of laser ranging to space debris objects to resolve close approaches to active satellites, to improve re-entry predictions of time and locations, and the more general SLR support during contingency situations. The office studies the determination of attitude and attitude motion of uncooperative objects with special focus on the combination of SLR, light-curve, and radar imaging data. Generating sufficiently precise information to allow for the acquisition of debris objects by a SLR sensor in a stare-and-chase scenario, or from externally provided orbital information, is also investigated. In our paper we will outline the motivation and objectives, as well as detail the current status of the various and parallel SLR-related SST and Space Debris Office activities at ESA. We will provide an overview on plans for SLR activities in research and development and in operational support. Current gaps in the standardisation of data exchange and sensor interfaces will be addressed, reflecting the need of coordinating multiple stations in all tasks.

Emerging role of Indian ocean on Indian northeast monsoon

NASA Astrophysics Data System (ADS)

Yadav, Ramesh Kumar

2013-07-01

This study examines the emerging role of Indian Ocean sea surface temperature (SST) on the inter-annual variability (IAV) of Indian north-east monsoon rainfall (NEMR). The IAV of NEMR is associated with the warm SST anomaly over east Bay-of-Bengal (BoB) (88.5oE-98.5oE; 8.5oN-15.5oN) and cool SST anomaly over east equatorial Indian Ocean (80.5oE-103.5oE; 6.5oS-3.5oN). The gradient of SST between these boxes (i.e. northern box minus southern box) shows strong and robust association with the Indian NEMR variability in the recent decades. For establishing the teleconnections, SST, mean sea level pressure, North Indian Ocean tropical storm track, and circulation data have been used. The study reveals that during the positive SST gradient years, the inter-tropical convergence zone (ITCZ) shifts northwards over the East Indian Ocean. The tropical depressions, storms and cyclones formed in the North Indian Ocean moves more zonally and strike the southern peninsular India and hence excess NEMR. While, during the negative SST gradient years, the ITCZ shifts southwards over the Indian Ocean. The tropical depressions, storms and cyclones formed in the North Indian Ocean moves more northwestward direction and after crossing 15oN latitude re-curve to north-east direction towards head BoB and misses southern peninsular India and hence, deficient NEMR.

[111In-DOTA]LTT-SS28, a first pansomatostatin radioligand for in vivo targeting of somatostatin receptor-positive tumors.

PubMed

Maina, Theodosia; Cescato, Renzo; Waser, Beatrice; Tatsi, Aikaterini; Kaloudi, Aikaterini; Krenning, Eric P; de Jong, Marion; Nock, Berthold A; Reubi, Jean Claude

2014-08-14

Radiolabeled pansomatostatin-like analogues are expected to enhance the diagnostic sensitivity and to expand the clinical indications of currently applied sst2-specific radioligands. In this study, we present the somatostatin mimic [DOTA]LTT-SS28 {[(DOTA)Ser1,Leu8,D-Trp22,Tyr25]SS28} and its 111In radioligand. [DOTA]LTT-SS28 exhibited a pansomatostatin-like profile binding with high affinity to all five hsst1-hsst5 subtypes (IC50 values in the lower nanomolar range). Furthermore, [DOTA]LTT-SS28 behaved as an agonist at hsst2, hsst3, and hsst5, efficiently stimulating internalization of the three receptor subtypes. Radioligand [111In-DOTA]LTT-SS28 showed good stability in the mouse bloodstream. It displayed strong and specific uptake in AR42J tumors 4 h postinjection (9.3±1.6% ID/g vs 0.3±0.0% ID/g during sst2 blockade) in mice. Significant and specific uptake was also observed in HEK293-hsst2-, HEK293-hsst3-, and HEK293-hsst5-expressing tumors (4.43±1.5, 4.88±1.1, and <3% ID/g, respectively, with values of <0.5% ID/g during receptor blockade). In conclusion, the somatostatin mimic [111In-DOTA]LTT-SS28 specifically localizes in sst2-, sst3-, and sst5-expressing xenografts in mice showing promise for multi-sst1-sst5 targeted tumor imaging.

Atmospheric Response to Zonal Variations in Midlatitude SST: Transient and Stationary Eddies and Their Feedback(.

NASA Astrophysics Data System (ADS)

Inatsu, Masaru; Mukougawa, Hitoshi; Xie, Shang-Ping

2003-10-01

Midwinter storm track response to zonal variations in midlatitude sea surface temperatures (SSTs) has been investigated using an atmospheric general circulation model under aquaplanet and perpetual-January conditions. Zonal wavenumber-1 SST variations with a meridionally confined structure are placed at various latitudes. Having these SST variations centered at 30°N leads to a zonally localized storm track, while the storm track becomes nearly zonally uniform when the same SST forcing is moved farther north at 40° and 50°N. Large (small) baroclinic energy conversion north of the warm (cold) SST anomaly near the axis of the storm track (near 40°N) is responsible for the large (small) storm growth. The equatorward transfer of eddy kinetic energy by the ageostrophic motion and the mechanical damping are important to diminish the storm track activity in the zonal direction.Significant stationary eddies form in the upper troposphere, with a ridge (trough) northeast of the warm (cold) SST anomaly at 30°N. Heat and vorticity budget analyses indicate that zonally localized condensational heating in the storm track is the major cause for these stationary eddies, which in turn exert a positive feedback to maintain the localized storm track by strengthening the vertical shear near the surface. These results indicate an active role of synoptic eddies in inducing deep, tropospheric-scale response to midlatitude SST variations. Finally, the application of the model results to the real atmosphere is discussed.

Analysis of purified glabra3-shapeshifter trichomes reveals a role for NOECK in regulating early trichome morphogenic events.

PubMed

Gilding, Edward K; Marks, M David

2010-10-01

Transcriptome analysis using the Affymetrix ATH1 platform has been completed on purified trichomes from the gl3-sst mutant. These trichomes display immature features, such as glassy cell walls and blunted branches. The gl3-sst trichome transcriptome was greatly enriched for genes involved in lipid biosynthesis, including those mediating the synthesis of fatty acids and wax. In addition, gl3-sst trichomes displayed reduced expression of the R3 MYBs TRY and CPC, which normally function to limit trichome development. The expression of the MIXTA-like MYB gene NOK was elevated. Members of the MIXTA-like family promote conical cell outgrowth, and in some cases, trichome initiation in diverse plant species. In contrast, NOK limits trichome outgrowth in wild-type Arabidopsis plants. Similar to other MIXTA-like genes, NOK was required for the expansion of gl3-sst trichomes, as the gl3-sst nok double mutant trichomes were greatly reduced in size. Expression of NOK in nok mutants reduced branch formation, whereas in gl3-sst nok, NOK expression promoted trichome cell outgrowth, illustrating duel roles for NOK in both promoting and limiting trichome development. MIXTA-like genes from phylogenetically diverse plant species could substitute for NOK in both nok and gl3-sst nok backgrounds. These findings suggest that certain aspects of NOK and MIXTA-like gene function have been conserved. © 2010 The Authors. Journal compilation © 2010 Blackwell Publishing Ltd.

Numerical Simulation of Atmospheric Response to Pacific Tropical Instability Waves(.

NASA Astrophysics Data System (ADS)

Small, R. Justin; Xie, Shang-Ping; Wang, Yuqing

2003-11-01

Tropical instability waves (TIWs) are 1000-km-long waves that appear along the sea surface temperature (SST) front of the equatorial cold tongue in the eastern Pacific. The study investigates the atmospheric planetary boundary layer (PBL) response to TIW-induced SST variations using a high-resolution regional climate model. An investigation is made of the importance of pressure gradients induced by changes in air temperature and moisture, and vertical mixing, which is parameterized in the model by a 1.5-level turbulence closure scheme. Significant turbulent flux anomalies of sensible and latent heat are caused by changes in the air sea temperature and moisture differences induced by the TIWs. Horizontal advection leads to the occurrence of the air temperature and moisture extrema downwind of the SST extrema. High and low hydrostatic surface pressures are then located downwind of the cold and warm SST patches, respectively. The maximum and minimum wind speeds occur in phase with SST, and a thermally direct circulation is created. The momentum budget indicates that pressure gradient, vertical mixing, and horizontal advection dominate. In the PBL the vertical mixing acts as a frictional drag on the pressure-gradient-driven winds. Over warm SST the mixed layer deepens relative to over cold SST. The model simulations of the phase and amplitude of wind velocity, wind convergence, and column-integrated water vapor perturbations due to TIWs are similar to those observed from satellite and in situ data.

Sea surface temperature measurements by the along-track scanning radiometer on the ERS 1 satellite: Early results

NASA Astrophysics Data System (ADS)

Mutlow, C. T.; ZáVody, A. M.; Barton, I. J.; Llewellyn-Jones, D. T.

1994-11-01

The along-track scanning radiometer (ATSR) was launched in July 1991 on the European Space Agency's first remote sensing satellite, ERS 1. An initial analysis of ATSR data demonstrates that the sea surface temperature (SST) can be measured from space with very high accuracy. Comparison of simultaneous measurements of SST made from ATSR and from a ship-borne radiometer show that they agree to within 0.3°C. To assess data consistency, a complementary analysis of SST data from ATSR was also carried out. The ATSR global SST field was compared on a daily basis with daily SST analysis of the United Kingdom Meteorological Office (UKMO). The ATSR global field is consistently within 1.0°C of the UKMO analysis. Also, to demonstrate the benefits of along-track scanning SST determination, the ATSR SST data were compared with high-quality bulk temperature observations from drifting buoys. The likely causes of the differences between ATSR and the bulk temperature data are briefly discussed. These results provide early confidence in the quantitative benefit of ATSR's two-angle view of the Earth and its high radiometric performance and show a significant advance on the data obtained from other spaceborne sensors. It should be noted that these measurements were made at a time when the atmosphere was severely contaminated with volcanic aerosol particles, which degrade infrared measurements of the Earth's surface made from space.

Sea Surface Temperature and Seawater Oxygen Isotope Variability Recorded in a Madagascar Coral Record

NASA Astrophysics Data System (ADS)

Zinke, J.; Dullo, W. Chr; Eisenhauer, A.

2003-04-01

We analysed a 336 year coral oxygen isotope record off southwest Madagascar in the Mozambique Channel. Based on temporal variability of skeletal oxygen isotopes annual mean sea surface temperatures are reconstructed for the period from 1659 to 1995. Sr/Ca ratios were measured for selected windows with monthly resolution (1973 to 1995, 1863 to 1910, 1784 to 1809, 1688 to 1710) to validate the SST reconstructions derived from oxygen isotopes. The coral proxy data were validated against gridded SST data sets. The coral oxygen isotope record is coherent with Kaplan-SST and GISST2.3b on an interdecadal frequency of 17 years, which is the most prominent frequency band observed in this region. The Sr/Ca-SST agree well with SST observations in the validation period (1863 to 1910), whereas the d18O derived SST show largest discrepencies during this time interval. By taking into account the SST values derived from coral Sr/Ca, we were able to reconstruct d18O seawater variability. This indicates that d18O seawater variations contributed significantly to interannual and interdecadal variations in coral d18O. We propose that the local surface-ocean evaporation-precipitation balance and remote forcing by ENSO via South Equatorial Current and/or Indonesian throughflow variability may contribute to observed d18O variability. Our results indicate that coral d18O may be used to reconstruct temporal variations in the fresh water balance within the Indian Ocean on interannual to interdecadal time scales.

Mid-Pliocene equatorial Pacific sea surface temperature reconstruction: a multi-proxy perspective

USGS Publications Warehouse

Dowsett, Harry J.; Robinson, Marci M.

2009-01-01

The Mid-Pliocene is the most recent interval of sustained global warmth, which can be used to examine conditions predicted for the near future. An accurate spatial representation of the low-latitude Mid-Pliocene Pacific surface ocean is necessary to understand past climate change in the light of forecasts of future change. Mid-Pliocene sea surface temperature (SST) anomalies show a strong contrast between the western equatorial Pacific (WEP) and eastern equatorial Pacific (EEP) regardless of proxy (faunal, alkenone and Mg/Ca). All WEP sites show small differences from modern mean annual temperature, but all EEP sites show significant positive deviation from present-day temperatures by as much as 4.4°C. Our reconstruction reflects SSTs similar to modern in the WEP, warmer than modern in the EEP and eastward extension of the WEP warm pool. The east-west equatorial Pacific SST gradient is decreased, but the pole to equator gradient does not change appreciably. We find it improbable that increased greenhouse gases (GHG) alone would cause such a heterogeneous warming and more likely that the cause of Mid-Pliocene warmth is a combination of several forcings including both increased meridional heat transport and increased GHG.

Mid-Pliocene equatorial Pacific sea surface temperature reconstruction: A multi-proxy perspective

USGS Publications Warehouse

Dowsett, H.J.; Robinson, M.M.

2009-01-01

The Mid-Pliocene is the most recent interval of sustained global warmth, which can be used to examine conditions predicted for the near future. An accurate spatial representation of the low-latitude Mid-Pliocene Pacific surface ocean is necessary to understand past climate change in the light of forecasts of future change. Mid-Pliocene sea surface temperature (SST) anomalies show a strong contrast between the western equatorial Pacific (WEP) and eastern equatorial Pacific (EEP) regardless of proxy (faunal, alkenone and Mg/Ca). All WEP sites show small differences from modern mean annual temperature, but all EEP sites show significant positive deviation from present-day temperatures by as much as 4.4??C. Our reconstruction reflects SSTs similar to modern in the WEP, warmer than modern in the EEP and eastward extension of the WEP warm pool. The east-west equatorial Pacific SST gradient is decreased, but the pole to equator gradient does not change appreciably. We find it improbable that increased greenhouse gases (GHG) alone would cause such a heterogeneous warming and more likely that the cause of Mid-Pliocene warmth is a combination of several forcings including both increased meridional heat transport and increased GHG. ?? 2008 The Royal Society.

Potential regulation on the climatic effect of Tibetan Plateau heating by tropical air-sea coupling in regional models

NASA Astrophysics Data System (ADS)

Wang, Ziqian; Duan, Anmin; Yang, Song

2018-05-01

Based on the conventional weather research and forecasting (WRF) model and the air-sea coupled mode WRF-OMLM, we investigate the potential regulation on the climatic effect of Tibetan Plateau (TP) heating by the air-sea coupling over the tropical Indian Ocean and western Pacific. Results indicate that the TP heating significantly enhances the southwesterly monsoon circulation over the northern Indian Ocean and the South Asia subcontinent. The intensified southwesterly wind cools the sea surface mainly through the wind-evaporation-SST (sea surface temperature) feedback. Cold SST anomaly then weakens monsoon convective activity, especially that over the Bay of Bengal, and less water vapor is thus transported into the TP along its southern slope from the tropical oceans. As a result, summer precipitation decreases over the TP, which further weakens the TP local heat source. Finally, the changed TP heating continues to influence the summer monsoon precipitation and atmospheric circulation. To a certain extent, the air-sea coupling over the adjacent oceans may weaken the effect of TP heating on the mean climate in summer. It is also implied that considerations of air-sea interaction are necessary in future simulation studies of the TP heating effect.