ARM/GCSS/SPARC TWP-ICE CRM Intercomparison Study

NASA Technical Reports Server (NTRS)

Fridlind, Ann; Ackerman, Andrew; Petch, Jon; Field, Paul; Hill, Adrian; McFarquhar, Greg; Xie, Shaocheng; Zhang, Minghua

2010-01-01

Specifications are provided for running a cloud-resolving model (CRM) and submitting results in a standardized format for inclusion in a n intercomparison study and archiving for public access. The simulated case study is based on measurements obtained during the 2006 Tropical Warm Pool - International Cloud Experiment (TWP-ICE) led by the U. S. department of Energy Atmospheric Radiation Measurement (ARM) program. The modeling intercomparison study is based on objectives developed in concert with the Stratospheric Processes And their Role in Climate (SPARC) program and the GEWEX cloud system study (GCSS) program. The Global Energy and Water Cycle Experiment (GEWEX) is a core project of the World Climate Research PRogramme (WCRP).

Final Report for High Latitude Climate Modeling: ARM Takes Us Beyond Case Studies

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

Russell, Lynn M; Lubin, Dan

2013-06-18

The main thrust of this project was to devise a method by which the majority of North Slope of Alaska (NSA) meteorological and radiometric data, collected on a daily basis, could be used to evaluate and improve global climate model (GCM) simulations and their parameterizations, particularly for cloud microphysics. Although the standard ARM Program sensors for a less complete suite of instruments for cloud and aerosol studies than the instruments on an intensive field program such as the 2008 Indirect and Semi-Direct Aerosol Campaign (ISDAC), the advantage they offer lies in the long time base and large volume of datamore » that covers a wide range of meteorological and climatological conditions. The challenge has been devising a method to interpret the NSA data in a practical way, so that a wide variety of meteorological conditions in all seasons can be examined with climate models. If successful, climate modelers would have a robust alternative to the usual “case study” approach (i.e., from intensive field programs only) for testing and evaluating their parameterizations’ performance. Understanding climate change on regional scales requires a broad scientific consideration of anthropogenic influences that goes beyond greenhouse gas emissions to also include aerosol-induced changes in cloud properties. For instance, it is now clear that on small scales, human-induced aerosol plumes can exert microclimatic radiative and hydrologic forcing that rivals that of greenhouse gas–forced warming. This project has made significant scientific progress by investigating what causes successive versions of climate models continue to exhibit errors in cloud amount, cloud microphysical and radiative properties, precipitation, and radiation balance, as compared with observations and, in particular, in Arctic regions. To find out what is going wrong, we have tested the models' cloud representation over the full range of meteorological conditions found in the Arctic using the ARM North Slope of Alaska (NSA) data.« less

CCPP-ARM Parameterization Testbed Model Forecast Data

DOE Data Explorer

Klein, Stephen

2008-01-15

Dataset contains the NCAR CAM3 (Collins et al., 2004) and GFDL AM2 (GFDL GAMDT, 2004) forecast data at locations close to the ARM research sites. These data are generated from a series of multi-day forecasts in which both CAM3 and AM2 are initialized at 00Z every day with the ECMWF reanalysis data (ERA-40), for the year 1997 and 2000 and initialized with both the NASA DAO Reanalyses and the NCEP GDAS data for the year 2004. The DOE CCPP-ARM Parameterization Testbed (CAPT) project assesses climate models using numerical weather prediction techniques in conjunction with high quality field measurements (e.g. ARM data).

Charter for the ARM Atmospheric Modeling Advisory Group

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

Advisory Group, ARM Atmospheric Modeling

The Atmospheric Modeling Advisory Group of the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility is guided by the following: 1. The group will provide feedback on the overall project plan including input on how to address priorities and trade-offs in the modeling and analysis workflow, making sure the modeling follows general best practices, and reviewing the recommendations provided to ARM for the workflow implementation. 2. The group will consist of approximately 6 members plus the PI and co-PI of the Large-Eddy Simulation (LES) ARM Symbiotic Simulation and Observation (LASSO) pilot project. The ARM Technical Director,more » or his designee, serves as an ex-officio member. This size is chosen based on the ability to efficiently conduct teleconferences and to span the general needs for input to the LASSO pilot project.« less

Measurement Capabilities of the DOE ARM Aerial Facility

NASA Astrophysics Data System (ADS)

Schmid, B.; Tomlinson, J. M.; Hubbe, J.; Comstock, J. M.; Kluzek, C. D.; Chand, D.; Pekour, M. S.

2012-12-01

The Department of Energy Atmospheric Radiation Measurement (ARM) Program is a climate research user facility operating stationary ground sites in three important climatic regimes that provide long-term measurements of climate relevant properties. ARM also operates mobile ground- and ship-based facilities to conduct shorter field campaigns (6-12 months) to investigate understudied climate regimes around the globe. Finally, airborne observations by ARM's Aerial Facility (AAF) enhance the surface-based ARM measurements by providing high-resolution in situ measurements for process understanding, retrieval algorithm development, and model evaluation that is not possible using ground-based techniques. AAF started out in 2007 as a "virtual hangar" with no dedicated aircraft and only a small number of instruments owned by ARM. In this mode, AAF successfully carried out several missions contracting with organizations and investigators who provided their research aircraft and instrumentation. In 2009, the Battelle owned G-1 aircraft was included in the ARM facility. The G-1 is a large twin turboprop aircraft, capable of measurements up to altitudes of 7.5 km and a range of 2,800 kilometers. Furthermore the American Recovery and Reinvestment Act of 2009 provided funding for the procurement of seventeen new instruments to be used aboard the G-1 and other AAF virtual-hangar aircraft. AAF now executes missions in the virtual- and real-hangar mode producing freely available datasets for studying aerosol, cloud, and radiative processes in the atmosphere. AAF is also heavily engaged in the maturation and testing of newly developed airborne sensors to help foster the next generation of airborne instruments. In the presentation we will showcase science applications based on measurements from recent field campaigns such as CARES, CALWATER and TCAP.

Overview of the United States Department of Energy's ARM (Atmospheric Radiation Measurement) Program

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

Stokes, G.M.; Tichler, J.L.

The Department of Energy (DOE) is initiating a major atmospheric research effort, the Atmospheric Radiation Measurement Program (ARM). The program is a key component of DOE's research strategy to address global climate change and is a direct continuation of DOE's decade-long effort to improve the ability of General Circulation Models (GCMs) to provide reliable simulations of regional, and long-term climate change in response to increasing greenhouse gases. The effort is multi-disciplinary and multi-agency, involving universities, private research organizations and more than a dozen government laboratories. The objective of the ARM Research is to provide an experimental testbed for the studymore » of important atmospheric effects, particularly cloud and radiative processes, and to test parameterizations of these processes for use in atmospheric models. This effort will support the continued and rapid improvement of GCM predictive capability. 2 refs.« less

ARM Mentor Selection Process

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

Sisterson, D. L.

2015-10-01

The Atmospheric Radiation Measurement (ARM) Program was created in 1989 with funding from the U.S. Department of Energy (DOE) to develop several highly instrumented ground stations to study cloud formation processes and their influence on radiative transfer. In 2003, the ARM Program became a national scientific user facility, known as the ARM Climate Research Facility. This scientific infrastructure provides for fixed sites, mobile facilities, an aerial facility, and a data archive available for use by scientists worldwide through the ARM Climate Research Facility—a scientific user facility. The ARM Climate Research Facility currently operates more than 300 instrument systems that providemore » ground-based observations of the atmospheric column. To keep ARM at the forefront of climate observations, the ARM infrastructure depends heavily on instrument scientists and engineers, also known as lead mentors. Lead mentors must have an excellent understanding of in situ and remote-sensing instrumentation theory and operation and have comprehensive knowledge of critical scale-dependent atmospheric processes. They must also possess the technical and analytical skills to develop new data retrievals that provide innovative approaches for creating research-quality data sets. The ARM Climate Research Facility is seeking the best overall qualified candidate who can fulfill lead mentor requirements in a timely manner.« less

Precipitation Estimation from the ARM Distributed Radar Network During the MC3E Campaign

NASA Astrophysics Data System (ADS)

Theisen, A. K.; Giangrande, S. E.; Collis, S. M.

2012-12-01

The DOE - NASA Midlatitude Continental Convective Cloud Experiment (MC3E) was the first demonstration of the Atmospheric Radiation Measurement (ARM) Climate Research Facility scanning precipitation radar platforms. A goal for the MC3E field campaign over the Southern Great Plains (SGP) facility was to demonstrate the capabilities of ARM polarimetric radar systems for providing unique insights into deep convective storm evolution and microphysics. One practical application of interest for climate studies and the forcing of cloud resolving models is improved Quantitative Precipitation Estimates (QPE) from ARM radar systems positioned at SGP. This study presents the results of ARM radar-based precipitation estimates during the 2-month MC3E campaign. Emphasis is on the usefulness of polarimetric C-band radar observations (CSAPR) for rainfall estimation to distances within 100 km of the Oklahoma SGP facility. Collocated ground disdrometer resources, precipitation profiling radars and nearby surface Oklahoma Mesonet gauge records are consulted to evaluate potential ARM radar-based rainfall products and optimal methods. Rainfall products are also evaluated against the regional NEXRAD-standard observations.

Warming increases the risk of civil war in Africa.

PubMed

Burke, Marshall B; Miguel, Edward; Satyanath, Shanker; Dykema, John A; Lobell, David B

2009-12-08

Armed conflict within nations has had disastrous humanitarian consequences throughout much of the world. Here we undertake the first comprehensive examination of the potential impact of global climate change on armed conflict in sub-Saharan Africa. We find strong historical linkages between civil war and temperature in Africa, with warmer years leading to significant increases in the likelihood of war. When combined with climate model projections of future temperature trends, this historical response to temperature suggests a roughly 54% increase in armed conflict incidence by 2030, or an additional 393,000 battle deaths if future wars are as deadly as recent wars. Our results suggest an urgent need to reform African governments' and foreign aid donors' policies to deal with rising temperatures.

Strategy for long-term 3D cloud-resolving simulations over the ARM SGP site and preliminary results

NASA Astrophysics Data System (ADS)

Lin, W.; Liu, Y.; Song, H.; Endo, S.

2011-12-01

Parametric representations of cloud/precipitation processes continue having to be adopted in climate simulations with increasingly higher spatial resolution or with emerging adaptive mesh framework; and it is only becoming more critical that such parameterizations have to be scale aware. Continuous cloud measurements at DOE's ARM sites have provided a strong observational basis for novel cloud parameterization research at various scales. Despite significant progress in our observational ability, there are important cloud-scale physical and dynamical quantities that are either not currently observable or insufficiently sampled. To complement the long-term ARM measurements, we have explored an optimal strategy to carry out long-term 3-D cloud-resolving simulations over the ARM SGP site using Weather Research and Forecasting (WRF) model with multi-domain nesting. The factors that are considered to have important influences on the simulated cloud fields include domain size, spatial resolution, model top, forcing data set, model physics and the growth of model errors. The hydrometeor advection that may play a significant role in hydrological process within the observational domain but is often lacking, and the limitations due to the constraint of domain-wide uniform forcing in conventional cloud system-resolving model simulations, are at least partly accounted for in our approach. Conventional and probabilistic verification approaches are employed first for selected cases to optimize the model's capability of faithfully reproducing the observed mean and statistical distributions of cloud-scale quantities. This then forms the basis of our setup for long-term cloud-resolving simulations over the ARM SGP site. The model results will facilitate parameterization research, as well as understanding and dissecting parameterization deficiencies in climate models.

Single-Column Modeling, GCM Parameterizations and Atmospheric Radiation Measurement Data

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

Somerville, R.C.J.; Iacobellis, S.F.

2005-03-18

Our overall goal is identical to that of the Atmospheric Radiation Measurement (ARM) Program: the development of new and improved parameterizations of cloud-radiation effects and related processes, using ARM data at all three ARM sites, and the implementation and testing of these parameterizations in global and regional models. To test recently developed prognostic parameterizations based on detailed cloud microphysics, we have first compared single-column model (SCM) output with ARM observations at the Southern Great Plains (SGP), North Slope of Alaska (NSA) and Topical Western Pacific (TWP) sites. We focus on the predicted cloud amounts and on a suite of radiativemore » quantities strongly dependent on clouds, such as downwelling surface shortwave radiation. Our results demonstrate the superiority of parameterizations based on comprehensive treatments of cloud microphysics and cloud-radiative interactions. At the SGP and NSA sites, the SCM results simulate the ARM measurements well and are demonstrably more realistic than typical parameterizations found in conventional operational forecasting models. At the TWP site, the model performance depends strongly on details of the scheme, and the results of our diagnostic tests suggest ways to develop improved parameterizations better suited to simulating cloud-radiation interactions in the tropics generally. These advances have made it possible to take the next step and build on this progress, by incorporating our parameterization schemes in state-of-the-art 3D atmospheric models, and diagnosing and evaluating the results using independent data. Because the improved cloud-radiation results have been obtained largely via implementing detailed and physically comprehensive cloud microphysics, we anticipate that improved predictions of hydrologic cycle components, and hence of precipitation, may also be achievable. We are currently testing the performance of our ARM-based parameterizations in state-of-the--art global and regional models. One fruitful strategy for evaluating advances in parameterizations has turned out to be using short-range numerical weather prediction as a test-bed within which to implement and improve parameterizations for modeling and predicting climate variability. The global models we have used to date are the CAM atmospheric component of the National Center for Atmospheric Research (NCAR) CCSM climate model as well as the National Centers for Environmental Prediction (NCEP) numerical weather prediction model, thus allowing testing in both climate simulation and numerical weather prediction modes. We present detailed results of these tests, demonstrating the sensitivity of model performance to changes in parameterizations.« less

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

Gustafson, William I.; Vogelmann, Andrew M.; Cheng, Xiaoping

The Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility began a pilot project in May 2015 to design a routine, high-resolution modeling capability to complement ARM’s extensive suite of measurements. This modeling capability has been named the Large-Eddy Simulation (LES) ARM Symbiotic Simulation and Observation (LASSO) project. The initial focus of LASSO is on shallow convection at the ARM Southern Great Plains (SGP) Climate Research Facility. The availability of LES simulations with concurrent observations will serve many purposes. LES helps bridge the scale gap between DOE ARM observations and models, and the use of routine LES addsmore » value to observations. It provides a self-consistent representation of the atmosphere and a dynamical context for the observations. Further, it elucidates unobservable processes and properties. LASSO will generate a simulation library for researchers that enables statistical approaches beyond a single-case mentality. It will also provide tools necessary for modelers to reproduce the LES and conduct their own sensitivity experiments. Many different uses are envisioned for the combined LASSO LES and observational library. For an observationalist, LASSO can help inform instrument remote sensing retrievals, conduct Observation System Simulation Experiments (OSSEs), and test implications of radar scan strategies or flight paths. For a theoretician, LASSO will help calculate estimates of fluxes and co-variability of values, and test relationships without having to run the model yourself. For a modeler, LASSO will help one know ahead of time which days have good forcing, have co-registered observations at high-resolution scales, and have simulation inputs and corresponding outputs to test parameterizations. Further details on the overall LASSO project are available at https://www.arm.gov/capabilities/modeling/lasso.« less

Determination of the spatial variability of temperature and moisture near a tropical Pacific island with MTI satellite images

NASA Astrophysics Data System (ADS)

Kurzeja, Robert J.; O'Steen, Byron L.; Pendergast, Malcolm M.

2002-01-01

The Tropical Pacific Island of Nauru is a US DOE ARM observation site that monitors tropical climate and atmospheric radiation. This observation site is ideal for validating MTI images because of the extensive deployment of continuously operating instruments. MTI images are also useful in assessing the effect of the island on the ocean climate and on the ARM data. An MTI image has been used to determine the spatial distribution of water vapor and sea-surface temperature near the island. The results are compared with a three-dimensional numerical model simulation.

Decadal Vision Progress Report Implementation Plans and Status for the Next Generation ARM Facility

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

Mather, James

The reconfiguration of the ARM facility, formally initiated in early 2014, is geared toward implementing the Next Generation of the ARM Facility, which will more tightly link ARM measurements and atmospheric models. The strategy is outlined in the ARM Climate Research Facility Decadal Vision (DOE 2014a). The strategy includes the implementation of a high-resolution model, initially at the Southern Great Plains (SGP) site, and enhancements at the SGP and North Slope of Alaska (NSA) sites to provide additional observations to support modeling and process studies. Enhancements at the SGP site focus on ground-based instruments while enhancements at the NSA makemore » use of Unmanned Aerial Systems (UAS) and Tethered Balloon Systems (TBS). It is also recognized that new data tools and data products will need to be developed to take full advantage of these improvements. This document provides an update on the status of these ARM facility enhancements, beginning with the measurement enhancements at the SGP and NSA, followed by a discussion of the modeling project including associated data-processing activities.« less

Evaluation of a Mesoscale Convective System in Variable-Resolution CESM

NASA Astrophysics Data System (ADS)

Payne, A. E.; Jablonowski, C.

2017-12-01

Warm season precipitation over the Southern Great Plains (SGP) follows a well observed diurnal pattern of variability, peaking at night-time, due to the eastward propagation of mesoscale convection systems that develop over the eastern slopes of the Rockies in the late afternoon. While most climate models are unable to adequately capture the organization of convection and characteristic pattern of precipitation over this region, models with high enough resolution to explicitly resolve convection show improvement. However, high resolution simulations are computationally expensive and, in the case of regional climate models, are subject to boundary conditions. Newly developed variable resolution global climate models strike a balance between the benefits of high-resolution regional climate models and the large-scale dynamics of global climate models and low computational cost. Recently developed parameterizations that are insensitive to the model grid scale provide a way to improve model performance. Here, we present an evaluation of the newly available Cloud Layers Unified by Binormals (CLUBB) parameterization scheme in a suite of variable-resolution CESM simulations with resolutions ranging from 110 km to 7 km within a regionally refined region centered over the SGP Atmospheric Radiation Measurement (ARM) site. Simulations utilize the hindcast approach developed by the Department of Energy's Cloud-Associated Parameterizations Testbed (CAPT) for the assessment of climate models. We limit our evaluation to a single mesoscale convective system that passed over the region on May 24, 2008. The effects of grid-resolution on the timing and intensity of precipitation, as well as, on the transition from shallow to deep convection are assessed against ground-based observations from the SGP ARM site, satellite observations and ERA-Interim reanalysis.

Understanding How Biomass Burning Impacts Climate Change

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

Aiken, Allison

2016-09-27

Biomass burning in Africa is creating a plume that spreads across the Atlantic Ocean all the way to Brazil. Allison Aiken, a research scientist at Los Alamos National Laboratory, collects data about the black carbon aerosols within this plume and their impact on the environment to help improve global climate modeling. A leader in energy science, Los Alamos develops climate models in support of the Laboratory’s mission to strengthen the nation’s energy security. Allison’s work is part of FIDO, a field operations team funded by the Energy Department’s Office of Science’s ARM Climate Research Facility.

Seasonal Atmospheric and Oceanic Predictions

NASA Technical Reports Server (NTRS)

Roads, John; Rienecker, Michele (Technical Monitor)

2003-01-01

Several projects associated with dynamical, statistical, single column, and ocean models are presented. The projects include: 1) Regional Climate Modeling; 2) Statistical Downscaling; 3) Evaluation of SCM and NSIPP AGCM Results at the ARM Program Sites; and 4) Ocean Forecasts.

An ARM Mobile Facility Designed for Marine Deployments

NASA Astrophysics Data System (ADS)

Wiscombe, W. J.

2007-05-01

The U.S. Dept. of Energy's ARM (Atmospheric Radiation Measurements) Program is designing a Mobile Facility exclusively for marine deployments. This marine facility is patterned after ARM's land Mobile Facility, which had its inaugural deployment at Point Reyes, California, in 2005, followed by deployments to Niger in 2006 and Germany in 2007 (ongoing), and a planned deployment to China in 2008. These facilities are primarily intended for the study of clouds, radiation, aerosols, and surface processes with a goal to include these processes accurately in climate models. They are preferably embedded within larger field campaigns which provide context. They carry extensive instrumentation (in several large containers) including: cloud radar, lidar, microwave radiometers, infrared spectrometers, broadband and narrowband radiometers, sonde-launching facilities, extensive surface aerosol measurements, sky imagers, and surface latent and sensible heat flux devices. ARM's Mobile Facilities are designed for 6-10 month deployments in order to capture climatically-relevant datasets. They are available to any scientist, U.S. or international, who wishes to submit a proposal during the annual Spring call. The marine facility will be adapted to, and ruggedized for, the harsh marine environment and will add a scanning two-frequency radar, a boundary-layer wind profiler, a shortwave spectrometer, and aerosol instrumentation adapted to typical marine aerosols like sea salt. Plans also include the use of roving small UAVs, automated small boats, and undersea autonomous vehicles in order to address the point-to-area-average problem which is so crucial for informing climate models. Initial deployments are planned for small islands in climatically- interesting cloud regimes, followed by deployments on oceanic platforms (like decommissioned oil rigs and the quasi-permanent platform of this session's title) and eventually on large ships like car carriers plying routine routes.

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

Bartholomew, M. J.

To improve the quantitative description of precipitation processes in climate models, the Atmospheric Radiation Measurement (ARM) Climate Research Facility deployed rain gauges located near disdrometers (DISD and VDIS data streams). This handbook deals specifically with the rain gauges that make the observations for the RAIN data stream. Other precipitation observations are made by the surface meteorology instrument suite (i.e., MET data stream).

Charter for the ARM Climate Research Facility Science Board

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

Ferrell, W

The objective of the ARM Science Board is to promote the Nation’s scientific enterprise by ensuring that the best quality science is conducted at the DOE’s User Facility known as the ARM Climate Research Facility. The goal of the User Facility is to serve scientific researchers by providing unique data and tools to facilitate scientific applications for improving understanding and prediction of climate science.

ARM Climate Research Facility Annual Report 2004

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

Voyles, J.

2004-12-31

Like a rock that slowly wears away beneath the pressure of a waterfall, planet earth?s climate is almost imperceptibly changing. Glaciers are getting smaller, droughts are lasting longer, and extreme weather events like fires, floods, and tornadoes are occurring with greater frequency. Why? Part of the answer is clouds and the amount of solar radiation they reflect or absorb. These two factors clouds and radiative transfer represent the greatest source of error and uncertainty in the current generation of general circulation models used for climate research and simulation. The U.S. Global Change Research Act of 1990 established an interagency programmore » within the Executive Office of the President to coordinate U.S. agency-sponsored scientific research designed to monitor, understand, and predict changes in the global environment. To address the need for new research on clouds and radiation, the U.S. Department of Energy (DOE) established the Atmospheric Radiation Measurement (ARM) Program. As part of the DOE?s overall Climate Change Science Program, a primary objective of the ARM Program is improved scientific understanding of the fundamental physics related to interactions between clouds and radiative feedback processes in the atmosphere.« less

Armed-conflict risks enhanced by climate-related disasters in ethnically fractionalized countries.

PubMed

Schleussner, Carl-Friedrich; Donges, Jonathan F; Donner, Reik V; Schellnhuber, Hans Joachim

2016-08-16

Social and political tensions keep on fueling armed conflicts around the world. Although each conflict is the result of an individual context-specific mixture of interconnected factors, ethnicity appears to play a prominent and almost ubiquitous role in many of them. This overall state of affairs is likely to be exacerbated by anthropogenic climate change and in particular climate-related natural disasters. Ethnic divides might serve as predetermined conflict lines in case of rapidly emerging societal tensions arising from disruptive events like natural disasters. Here, we hypothesize that climate-related disaster occurrence enhances armed-conflict outbreak risk in ethnically fractionalized countries. Using event coincidence analysis, we test this hypothesis based on data on armed-conflict outbreaks and climate-related natural disasters for the period 1980-2010. Globally, we find a coincidence rate of 9% regarding armed-conflict outbreak and disaster occurrence such as heat waves or droughts. Our analysis also reveals that, during the period in question, about 23% of conflict outbreaks in ethnically highly fractionalized countries robustly coincide with climatic calamities. Although we do not report evidence that climate-related disasters act as direct triggers of armed conflicts, the disruptive nature of these events seems to play out in ethnically fractionalized societies in a particularly tragic way. This observation has important implications for future security policies as several of the world's most conflict-prone regions, including North and Central Africa as well as Central Asia, are both exceptionally vulnerable to anthropogenic climate change and characterized by deep ethnic divides.

Armed-Conflict Risks Enhanced by Climate-Related Disasters in Ethnically Fractionalized Countries

NASA Astrophysics Data System (ADS)

Donner, R. V.; Schleussner, C. F.; Donges, J. F.; Schellnhuber, J.

2016-12-01

Social and political tensions keep on fueling armed conflicts around the world. Although each conflict is the result of an individual context-specific mixture of interconnected factors, ethnicity appears to play a prominent and almost ubiquitous role in many of them. This overall state of affairs is likely to be exacerbated by anthropogenic climate change and in particular climate-related natural disasters. Ethnic divides might serve as predetermined conflict lines in case of rapidly emerging societal tensions arising from disruptive events like natural disasters. Here, we hypothesize that climate-related disaster occurrence enhances armed-conflict outbreak risk in ethnically fractionalized countries. Using event coincidence analysis, we test this hypothesis based on data on armed-conflict outbreaks and climate-related natural disasters for the period 1980-2010. Globally, we find a coincidence rate of 9% regarding armed-conflict outbreak and disaster occurrence such as heat waves or droughts. Our analysis also reveals that, during the period in question, about 23% of conflict outbreaks in ethnically highly fractionalized countries robustly coincide with climatic calamities. Although we do not report evidence that climate-related disasters act as direct triggers of armed conflicts, the disruptive nature of these events seems to play out in ethnically fractionalized societies in a particularly tragic way. This observation has important implications for future security policies as several of the world's most conflict-prone regions, including North and Central Africa as well as Central Asia, are both exceptionally vulnerable to anthropogenic climate change and characterized by deep ethnic divides.

Assessment of diffuse radiation models in Azores

NASA Astrophysics Data System (ADS)

Magarreiro, Clarisse; Brito, Miguel; Soares, Pedro; Azevedo, Eduardo

2014-05-01

Measured irradiance databases usually consist of global solar radiation data with limited spatial coverage. Hence, solar radiation models have been developed to estimate the diffuse fraction from the measured global irradiation. This information is critical for the assessment of the potential of solar energy technologies; for example, the decision to use photovoltaic systems with tracking system. The different solar radiation models for this purpose differ on the parameters used as input. The simplest, and most common, are models which use global radiation information only. More sophisticated models require meteorological parameters such as information from clouds, atmospheric turbidity, temperature or precipitable water content. Most of these models comprise correlations with the clearness index, kt (portion of horizontal extra-terrestrial radiation reaching the Earth's surface) to obtain the diffuse fraction kd (portion of diffuse component from global radiation). The applicability of these different models is related to the local atmospheric conditions and its climatic characteristics. The models are not of general validity and can only be applicable to locations where the albedo of the surrounding terrain and the atmospheric contamination by dust are not significantly different from those where the corresponding methods were developed. Thus, models of diffuse fraction exhibit a relevant degree of location dependence: e.g. models developed considering data acquired in Europe are mainly linked to Northern, Central or, more recently, Mediterranean areas. The Azores Archipelago, with its particular climate and cloud cover characteristics, different from mainland Europe, has not yet been considered for the development of testing of such models. The Azorean climate reveals large amounts of cloud cover in its annual cycle, with spatial and temporal variabilities more complex than the common Summer/Winter pattern. This study explores the applicability of different existing correlation models of diffuse fraction and clearness index or other plain parameters to the Azorean region. Reliable data provided by the Atmospheric Radiation Measurements (ARM) Climate Research Facility from the Graciosa Island deployment of the ARM Mobile Facility (http://www.arm.gov/sites/amf/grw) was used to perform the analysis. Model results showed a tendency to underestimate higher values of diffuse radiation. From the performance results of the correlation models reviewed it was clear that there is room for improvement.

A Variable Resolution Atmospheric General Circulation Model for a Megasite at the North Slope of Alaska

NASA Astrophysics Data System (ADS)

Dennis, L.; Roesler, E. L.; Guba, O.; Hillman, B. R.; McChesney, M.

2016-12-01

The Atmospheric Radiation Measurement (ARM) climate research facility has three siteslocated on the North Slope of Alaska (NSA): Barrrow, Oliktok, and Atqasuk. These sites, incombination with one other at Toolik Lake, have the potential to become a "megasite" whichwould combine observational data and high resolution modeling to produce high resolutiondata products for the climate community. Such a data product requires high resolutionmodeling over the area of the megasite. We present three variable resolution atmosphericgeneral circulation model (AGCM) configurations as potential alternatives to stand-alonehigh-resolution regional models. Each configuration is based on a global cubed-sphere gridwith effective resolution of 1 degree, with a refinement in resolution down to 1/8 degree overan area surrounding the ARM megasite. The three grids vary in the size of the refined areawith 13k, 9k, and 7k elements. SquadGen, NCL, and GIMP are used to create the grids.Grids vary based upon the selection of areas of refinement which capture climate andweather processes that may affect a proposed NSA megasite. A smaller area of highresolution may not fully resolve climate and weather processes before they reach the NSA,however grids with smaller areas of refinement have a significantly reduced computationalcost compared with grids with larger areas of refinement. Optimal size and shape of thearea of refinement for a variable resolution model at the NSA is investigated.

3ARM: A Fast, Accurate Radiative Transfer Model for Use in Climate Models

NASA Technical Reports Server (NTRS)

Bergstrom, R. W.; Kinne, S.; Sokolik, I. N.; Toon, O. B.; Mlawer, E. J.; Clough, S. A.; Ackerman, T. P.; Mather, J.

1996-01-01

A new radiative transfer model combining the efforts of three groups of researchers is discussed. The model accurately computes radiative transfer in a inhomogeneous absorbing, scattering and emitting atmospheres. As an illustration of the model, results are shown for the effects of dust on the thermal radiation.

3ARM: A Fast, Accurate Radiative Transfer Model for use in Climate Models

NASA Technical Reports Server (NTRS)

Bergstrom, R. W.; Kinne, S.; Sokolik, I. N.; Toon, O. B.; Mlawer, E. J.; Clough, S. A.; Ackerman, T. P.; Mather, J.

1996-01-01

A new radiative transfer model combining the efforts of three groups of researchers is discussed. The model accurately computes radiative transfer in a inhomogeneous absorbing, scattering and emitting atmospheres. As an illustration of the model, results are shown for the effects of dust on the thermal radiation.

3ARM: A Fast, Accurate Radiative Transfer Model For Use in Climate Models

NASA Technical Reports Server (NTRS)

Bergstrom, R. W.; Kinne, S.; Sokolik, I. N.; Toon, O. B.; Mlawer, E. J.; Clough, S. A.; Ackerman, T. P.; Mather, J.

1996-01-01

A new radiative transfer model combining the efforts of three groups of researchers is discussed. The model accurately computes radiative transfer in a inhomogeneous absorbing, scattering and emitting atmospheres. As an illustration of the model, results are shown for the effects of dust on the thermal radiation.

Armed-conflict risks enhanced by climate-related disasters in ethnically fractionalized countries

PubMed Central

Schleussner, Carl-Friedrich; Donges, Jonathan F.; Donner, Reik V.; Schellnhuber, Hans Joachim

2016-01-01

Social and political tensions keep on fueling armed conflicts around the world. Although each conflict is the result of an individual context-specific mixture of interconnected factors, ethnicity appears to play a prominent and almost ubiquitous role in many of them. This overall state of affairs is likely to be exacerbated by anthropogenic climate change and in particular climate-related natural disasters. Ethnic divides might serve as predetermined conflict lines in case of rapidly emerging societal tensions arising from disruptive events like natural disasters. Here, we hypothesize that climate-related disaster occurrence enhances armed-conflict outbreak risk in ethnically fractionalized countries. Using event coincidence analysis, we test this hypothesis based on data on armed-conflict outbreaks and climate-related natural disasters for the period 1980–2010. Globally, we find a coincidence rate of 9% regarding armed-conflict outbreak and disaster occurrence such as heat waves or droughts. Our analysis also reveals that, during the period in question, about 23% of conflict outbreaks in ethnically highly fractionalized countries robustly coincide with climatic calamities. Although we do not report evidence that climate-related disasters act as direct triggers of armed conflicts, the disruptive nature of these events seems to play out in ethnically fractionalized societies in a particularly tragic way. This observation has important implications for future security policies as several of the world’s most conflict-prone regions, including North and Central Africa as well as Central Asia, are both exceptionally vulnerable to anthropogenic climate change and characterized by deep ethnic divides. PMID:27457927

Contribution to the development of DOE ARM Climate Modeling Best Estimate Data (CMBE) products: Satellite data over the ARM permanent and AMF sites: Final Report

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

Xie, B; Dong, X; Xie, S

2012-05-18

To support the LLNL ARM infrastructure team Climate Modeling Best Estimate (CMBE) data development, the University of North Dakota (UND)'s group will provide the LLNL team the NASA CERES and ISCCP satellite retrieved cloud and radiative properties for the periods when they are available over the ARM permanent research sites. The current available datasets, to date, are as follows: the CERES/TERRA during 200003-200812; the CERES/AQUA during 200207-200712; and the ISCCP during 199601-200806. The detailed parameters list below: (1) CERES Shortwave radiative fluxes (net and downwelling); (2) CERES Longwave radiative fluxes (upwelling) - (items 1 & 2 include both all-sky andmore » clear-sky fluxes); (3) CERES Layered clouds (total, high, middle, and low); (4) CERES Cloud thickness; (5) CERES Effective cloud height; (6) CERES cloud microphysical/optical properties; (7) ISCCP optical depth cloud top pressure matrix; (8) ISCCP derived cloud types (r.g., cirrus, stratus, etc.); and (9) ISCCP infrared derived cloud top pressures. (10) The UND group shall apply necessary quality checks to the original CERES and ISCCP data to remove suspicious data points. The temporal resolution for CERES data should be all available satellite overpasses over the ARM sites; for ISCCP data, it should be 3-hourly. The spatial resolution is the closest satellite field of view observations to the ARM surface sites. All the provided satellite data should be in a format that is consistent with the current ARM CMBE dataset so that the satellite data can be easily merged into the CMBE dataset.« less

ARM Best Estimate Data (ARMBE) Products for Climate Science for a Sustainable Energy Future (CSSEF)

DOE Data Explorer

Riihimaki, Laura; Gaustad, Krista; McFarlane, Sally

2014-06-12

This data set was created for the Climate Science for a Sustainable Energy Future (CSSEF) model testbed project and is an extension of the hourly average ARMBE dataset to other extended facility sites and to include uncertainty estimates. Uncertainty estimates were needed in order to use uncertainty quantification (UQ) techniques with the data.

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

Bartholomew, Mary Jane

To improve the quantitative description of precipitation processes in climate models, the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility deploys several types of rain gauges (MET, RAIN, and optical rain gauge [ORG] datastreams) as well as disdrometers (DISD and VDIS datastreams) at the Southern Great Plains (SGP) Site. This handbook deals specifically with the independent analog ORG (i.e., the ORG datastream).

The impact of ARM on climate modeling

DOE PAGES

Randall, David A.; Del Genio, Anthony D.; Donner, Lee J.; ...

2016-07-15

Climate models are among humanity’s most ambitious and elaborate creations. They are designed to simulate the interactions of the atmosphere, ocean, land surface, and cryosphere on time scales far beyond the limits of deterministic predictability and including the effects of time-dependent external forcings. The processes involved include radiative transfer, fluid dynamics, microphysics, and some aspects of geochemistry, biology, and ecology. The models explicitly simulate processes on spatial scales ranging from the circumference of Earth down to 100 km or smaller and implicitly include the effects of processes on even smaller scales down to a micron or so. In addition, themore » atmospheric component of a climate model can be called an atmospheric global circulation model (AGCM).« less

Enhanced Soundings for Local Coupling Studies: 2015 ARM Climate Research Facility Field Campaign

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

Ferguson, CR; Santanello, JA; Gentine, P

2015-11-01

Matching observed diurnal cycles is a fundamental yet extremely complex test for models. High temporal resolution measurements of surface turbulent heat fluxes and boundary layer properties are required to evaluate the daytime evolution of the boundary layer and its sensitivity to land-atmosphere coupling. To address this need, (12) one-day intensive observing periods (IOP) with enhanced radiosonding will be carried out at the ARM Southern Great Plains (SGP) Central Facility (CF) during summer 2015. Each IOP will comprise a single launch to correspond with the nighttime overpass of the A-Train of satellites (~0830 UTC) and hourly launches during daytime beginning frommore » 1130 UTC and ending at 2130 UTC. At 3-hourly intervals (i.e., 1140 UTC, 1440 UTC, 1740 UTC, and 2040 UTC) a duplicate second radiosonde will be launched 10 minutes subsequent to launch of the on-hour radiosonde for the purpose of assessing horizontal atmospheric variability. In summary, each IOP will have a 14-sounding supplement to the 6-hourly operational sounding schedule at the ARM-SGP CF. The IOP days will be decided before sunset on the preceding day, according to the judgment of the PI’s and taking into consideration daily weather forecasts and the operability of complimentary ARM-SGP CF instrumentation. An overarching goal of the project is to address how ARM could better observe land-atmosphere coupling to support the evaluation and refinement of coupled weather and climate models.« less

Understanding How Biomass Burning Impacts Climate Change

ScienceCinema

Aiken, Allison

2018-06-12

Biomass burning in Africa is creating a plume that spreads across the Atlantic Ocean all the way to Brazil. Allison Aiken, a research scientist at Los Alamos National Laboratory, collects data about the black carbon aerosols within this plume and their impact on the environment to help improve global climate modeling. A leader in energy science, Los Alamos develops climate models in support of the Laboratory’s mission to strengthen the nation’s energy security. Allison’s work is part of FIDO, a field operations team funded by the Energy Department’s Office of Science’s ARM Climate Research Facility.

Magic - Marine Arm Gpci Investigation of Clouds

NASA Astrophysics Data System (ADS)

Lewis, E. R.; Wiscombe, W. J.; Albrecht, B. A.; Bland, G.; Flagg, C. N.; Klein, S. A.; Kollias, P.; Mace, G. G.; Reynolds, M.; Schwartz, S. E.; Siebesma, P.; Teixeira, J.; Wood, R.; Zhang, M.

2012-12-01

MAGIC, the Marine ARM (Atmospheric Radiation Measurement program) GPCI Investigation of Clouds, will deploy the Second ARM Mobile Facility (AMF2) aboard the Horizon Lines cargo container ship M/V Spirit traversing the route between Los Angeles, CA and Honolulu, HI from October, 2012 through September, 2013 (except from a few months in the middle of this time period when the ship will be in dry dock). During this time AMF2 will observe and characterize the properties of clouds and precipitation, aerosols, and atmospheric radiation; standard meteorological and oceanographic variables; and atmospheric structure. There will also be Intensive Observational Periods (IOPs), one in January, 2013 and one in July, 2013 during which more detailed measurements of the atmospheric structure will be made. Clouds remain a major source of uncertainty in climate projections. In this context, subtropical marine boundary layer (MBL) clouds play a key role in cloud-climate feedbacks that are not well understood yet play a large role in biases both in seasonal coupled model forecasts and annual mean climate forecasts. In particular, current climate models do not accurately represent the transition from the stratocumulus (Sc) regime, with its high albedo and large impact on the global radiative balance of Earth, to shallow trade-wind cumulus (Cu), which play a fundamental role in global surface evaporation and also albedo. Climate models do not yet adequately parameterize the small-scale physical processes associated with turbulence, convection, and radiation in these clouds. Part of this inability results from lack of accurate data on these clouds and the conditions responsible for their properties, including aerosol properties, radiation, and atmospheric and oceanographic conditions. The primary objectives of MAGIC are to improve the representation of the Sc-to-Cu transition in climate models by characterizing the essential properties of this transition, and to produce the observed statistics of these Sc-to-Cu characteristics for the deployment period along the transect. This first marine deployment of AMF2 will yield an unparalleled and extremely rich data set that will greatly enhance the ability to understand and parameterize clouds and precipitation, aerosols, and radiation and the interactions among them; the processes that determine their properties; and factors that control these processes. Deployment of AMF2 on a ship that routinely traverses this route will provide a long-term data set over a vast cloud region which is of intense interest to climate modelers. Specifically, the proposed transect lies closely along the cross section used for the GPCI, and the data collected will provide constraint, validation, and support for this modeling effort, and for associated modeling efforts such as the CGILS and EUCLIPSE.

Analysis of the Variations in Rock Magnetic Properties of the Quaternary Blackwater Draw (Eolian) Formation, West Texas

NASA Astrophysics Data System (ADS)

Stine, J. M.; Ferguson, J. F.; Geissman, J. W.; Sweet, D. E.

2017-12-01

The Quaternary Blackwater Draw Formation consists of the surficial deposits ( 10 + m thick) that directly overlie the Neogene Ogallala Formation in the Southern High Plains (SHP). These Quaternary deposits display a rhythmic pattern where eolian derived sediments (loess) are in turn punctuated by several paleosol layers, implying that Quaternary glacial-interglacial climate cycles are recorded in the Blackwater Draw Formation. In order to investigate this hypothesis, several rock magnetic parameters obtained from the Blackwater Draw Formation were analyzed using exploratory data analysis (EDA) techniques. The Blackwater Draw Formation was sampled at high resolution (2.5-5 cm intervals in depth, which serves as a proxy for time). Rock magnetic parameters measured are bulk magnetic susceptibility (χ, median: 1.56 * 10-4 SI volume), anhysteretic remanent magnetization (ARM, median: 0.1612 A/m), and isothermal remanent magnetization (IRM, median: 2.5367 A/m) intensity, which allow for the determination of two common environmental magnetic ratios (ARM/χ and ARM/IRM, medians: 1051 and 0.068 respectively) that are often used to approximate magnetic grain size. The data were analyzed using robust EDA methods for classification, correlation, and signal extraction. Using these techniques, it becomes evident that a good correspondence exists between the geophysical data and the geologic model (stratigraphy). For example, the cross plots showed that the magnetic data segregate into clusters corresponding to stratigraphy. Smoothing of the magnetic ratio data produces an oscillatory signal that may correspond to climate cyclicity. Additionally the smoothed models show a noticeable change in periodicity, where the ARM, IRM and χ values in the uppermost section exhibit a much higher amplitude and lower frequency than the bottom part of the section (with the reverse being true for the ratios). When comparing the data to the geologic model this change appears to correlate with the Mid-Pleistocene Transition (MPT), when the Earth's climate cycle periodicity changed from 41 ka to 100 ka.

Impact Disdrometers Instrument Handbook

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

Bartholomew, Mary Jane

2016-03-01

To improve the quantitative description of precipitation processes in climate models, the U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) Climate Research Facility has been collecting observations of the drop size spectra of rain events since early in 2006. Impact disdrometers were the initial choice due to their reliability, ease of maintenance, and relatively low cost. Each of the two units deployed was accompanied by a nearby tipping bucket. In 2010, the tipping buckets were replaced by weighing buckets rain gauges. Five video disdrometers were subsequently purchased and are described in ARM’s VDIS Handbook.1 As of April 2011, three ofmore » the weighing bucket instruments were deployed, one was to travel with the second ARM Mobile Facility, and the fifth was a spare. Two of the video disdrometers were deployed, a third was to be deployed later in the spring of 2011, one was to travel with the second ARM Mobile Facility, and the last was a spare. Detailed descriptions of impact disdrometers and their datastreams are provided in this document.« less

Main outcomes of an RCT to pilot test reporting and feedback to foster research integrity climates in the VA.

PubMed

Martinson, Brian C; Mohr, David C; Charns, Martin P; Nelson, David; Hagel-Campbell, Emily; Bangerter, Ann; Bloomfield, Hanna E; Owen, Richard; Thrush, Carol R

2017-01-01

Assessing the integrity of research climates and sharing such information with research leaders may support research best practices. We report here results of a pilot trial testing the effectiveness of a reporting and feedback intervention using the Survey of Organizational Research Climate (SOuRCe). We randomized 41 Veterans Health Administration (VA) facilities to a phone-based intervention designed to help research leaders understand their survey results (enhanced arm) or to an intervention in which results were simply distributed to research leaders (basic arm). Primary outcomes were (1) whether leaders took action, (2) whether actions taken were consistent with the feedback received, and (3) whether responses differed by receptivity to quality improvement input. Research leaders from 25 of 42 (59%) VA facilities consented to participate in the study intervention and follow-up, of which 14 were at facilities randomized to the enhanced arm. We completed follow-up interviews with 21 of the 25 leaders (88%), 12 from enhanced arm facilities. While not statistically significant, the proportion of leaders reporting taking some action in response to the feedback was twice as high in the enhanced arm than in the basic arm (67% vs. 33%, p = .20). While also not statistically significant, a higher proportion of actions taken among facilities in the enhanced arm were responsive to the survey results than in the basic arm (42% vs. 22%, p = .64). Enhanced feedback of survey results appears to be a promising intervention that may increase the likelihood of responsive action to improve organizational climates. Due to the small sample size of this pilot study, even large percentage-point differences between study arms are not statistically distinguishable. This hypothesis should be tested in a larger trial.

Evaluation of corrosion fatigue and life prediction of lower arm for automotive suspension component

NASA Astrophysics Data System (ADS)

Kim, Yong-Sang; Kim, Jung-Gu

2017-01-01

Lower arm is one of the suspension components of automobile. It is suffered from driving vibration and corrosive environment, namely corrosion fatigue. In this study, corrosion fatigue property of lower arm was investigated, and a modified model based on Palmgren-Miner rule was developed to predict the lifetimes of corrosion fatigue. The corrosion fatigue life of lower arm was about 1/6 times shorter than fatigue life. Based on the results of corrosion fatigue tests and meteorological data in Seoul and Halifax, the corrosion fatigue life of lower arm was predicted. The satisfaction of 10-year and 300,000 km warranty was dominated by the climate of automobile driving. This prediction indicates that the weather condition or driving condition influences the life of automotive parts. Therefore, to determine the warranty of automotive parts, the driving condition has to be carefully considered.

Evaluation of Aerosol-cloud Interaction in the GISS Model E Using ARM Observations

NASA Technical Reports Server (NTRS)

DeBoer, G.; Bauer, S. E.; Toto, T.; Menon, Surabi; Vogelmann, A. M.

2013-01-01

Observations from the US Department of Energy's Atmospheric Radiation Measurement (ARM) program are used to evaluate the ability of the NASA GISS ModelE global climate model in reproducing observed interactions between aerosols and clouds. Included in the evaluation are comparisons of basic meteorology and aerosol properties, droplet activation, effective radius parameterizations, and surface-based evaluations of aerosol-cloud interactions (ACI). Differences between the simulated and observed ACI are generally large, but these differences may result partially from vertical distribution of aerosol in the model, rather than the representation of physical processes governing the interactions between aerosols and clouds. Compared to the current observations, the ModelE often features elevated droplet concentrations for a given aerosol concentration, indicating that the activation parameterizations used may be too aggressive. Additionally, parameterizations for effective radius commonly used in models were tested using ARM observations, and there was no clear superior parameterization for the cases reviewed here. This lack of consensus is demonstrated to result in potentially large, statistically significant differences to surface radiative budgets, should one parameterization be chosen over another.

Environmental assessment for the Atmospheric Radiation Measurement (ARM) Program: Southern Great Plains Cloud and Radiation Testbed (CART) site

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

Policastro, A.J.; Pfingston, J.M.; Maloney, D.M.

The Atmospheric Radiation Measurement (ARM) Program is aimed at supplying improved predictive capability of climate change, particularly the prediction of cloud-climate feedback. The objective will be achieved by measuring the atmospheric radiation and physical and meteorological quantities that control solar radiation in the earth`s atmosphere and using this information to test global climate and related models. The proposed action is to construct and operate a Cloud and Radiation Testbed (CART) research site in the southern Great Plains as part of the Department of Energy`s Atmospheric Radiation Measurement Program whose objective is to develop an improved predictive capability of global climatemore » change. The purpose of this CART research site in southern Kansas and northern Oklahoma would be to collect meteorological and other scientific information to better characterize the processes controlling radiation transfer on a global scale. Impacts which could result from this facility are described.« less

Final Technical Report for "Reducing tropical precipitation biases in CESM"

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

Larson, Vincent

In state-of-the-art climate models, each cloud type is treated using its own separate cloud parameterization and its own separate microphysics parameterization. This use of separate schemes for separate cloud regimes is undesirable because it is theoretically unfounded, it hampers interpretation of results, and it leads to the temptation to overtune parameters. In this grant, we have created a climate model that contains a unified cloud parameterization (“CLUBB”) and a unified microphysics parameterization (“MG2”). In this model, all cloud types --- including marine stratocumulus, shallow cumulus, and deep cumulus --- are represented with a single equation set. This model improves themore » representation of convection in the Tropics. The model has been compared with ARM observations. The chief benefit of the project is to provide a climate model that is based on a more theoretically rigorous formulation.« less

ARM Climate Research Facility Quarterly Ingest Status Report

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

Koontz, A.; Sivaraman, C.

2016-10-01

The purpose of this report is to provide a concise status update for ingests maintained by the Atmospheric Radiation Measurement (ARM) Climate Research Facility. The report is divided into the following sections: (1) new ingests for which development has begun, (2) progress on existing ingests, (3) future ingests that have been recently approved, (4) other work that leads to an ingest, and (5) top requested ingests from the ARM Data Archive. New information is highlighted in blue text.

ARM Climate Research Facility Quarterly Ingest Status Report

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

Koontz, A.; Sivaraman, C.

2016-07-01

The purpose of this report is to provide a concise status update for ingests maintained by the Atmospheric Radiation Measurement (ARM) Climate Research Facility. The report is divided into the following sections: (1) new ingests for which development has begun, (2) progress on existing ingests, (3) future ingests that have been recently approved, (4) other work that leads to an ingest, and (5) top requested ingests from the ARM Data Archive. New information is highlighted in blue text.

ARM Climate Modeling Best Estimate Lamont, OK Statistical Summary (ARMBE-CLDRAD SGPC1)

DOE Data Explorer

McCoy, Renata; Xie, Shaocheng

2010-01-26

Calculate monthly mean diurnal cycle based on the hourly CMBE data with qcflag >=-1 (>30% valid data within the averaged hour). For 2-D clouds, only data over the period when both MMCR and MPL were working are used.

ARM MJO Investigation Experiment on Gan Island (AMIE-Gan) Science Plan

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

Long, CL; Del Genio, A; Deng, M

2011-04-11

The overarching campaign, which includes the ARM Mobile Facility 2 (AMF2) deployment in conjunction with the Dynamics of the Madden-Julian Oscillation (DYNAMO) and the Cooperative Indian Ocean experiment on intraseasonal variability in the Year 2011 (CINDY2011) campaigns, is designed to test several current hypotheses regarding the mechanisms responsible for Madden-Julian Oscillation (MJO) initiation and propagation in the Indian Ocean area. The synergy between the proposed AMF2 deployment with DYNAMO/CINDY2011, and the corresponding funded experiment on Manus, combine for an overarching ARM MJO Investigation Experiment (AMIE) with two components: AMF2 on Gan Island in the Indian Ocean (AMIE-Gan), where the MJOmore » initiates and starts its eastward propagation; and the ARM Manus site (AMIE-Manus), which is in the general area where the MJO usually starts to weaken in climate models. AMIE-Gan will provide measurements of particular interest to Atmospheric System Research (ASR) researchers relevant to improving the representation of MJO initiation in climate models. The framework of DYNAMO/CINDY2011 includes two proposed island-based sites and two ship-based locations forming a square pattern with sonde profiles and scanning precipitation and cloud radars at both island and ship sites. These data will be used to produce a Variational Analysis data set coinciding with the one produced for AMIE-Manus. The synergy between AMIE-Manus and AMIE-Gan will allow studies of the initiation, propagation, and evolution of the convective cloud population within the framework of the MJO. As with AMIE-Manus, AMIE-Gan/DYNAMO also includes a significant modeling component geared toward improving the representation of MJO initiation and propagation in climate and forecast models. This campaign involves the deployment of the second, marine-capable, AMF; all of the included measurement systems; and especially the scanning and vertically pointing radars. The campaign will include sonde launches at a rate of eight per day for the duration of the deployment. The increased sonde launches for the entire period matches that of the AMIE-Manus campaign and makes possible a far more robust Variational Analysis forcing data set product for the entire campaign, and thus better capabilities for modeling studies and synergistic research using the data from both AMIE sites.« less

Aerosols and Clouds: In Cahoots to Change Climate

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

Berg, Larry

Key knowledge gaps persist despite advances in the scientific understanding of how aerosols and clouds evolve and affect climate. The Two-Column Aerosol Project, or TCAP, was designed to provide a detailed set of observations to tackle this area of unknowns. Led by PNNL atmospheric scientist Larry Berg, ARM's Climate Research Facility was deployed in Cape Cod, Massachusetts for the 12-month duration of TCAP, which came to a close in June 2013. "We are developing new tools to look at particle chemistry, like our mass spectrometer used in TCAP that can tell us the individual chemical composition of an aerosol," saidmore » Berg. "Then, we'll run our models and compare it with the data that we have to make sure we're getting correct answers and make sure our climate models are reflecting the best information."« less

Aerosols and Clouds: In Cahoots to Change Climate

ScienceCinema

Berg, Larry

2018-01-16

Key knowledge gaps persist despite advances in the scientific understanding of how aerosols and clouds evolve and affect climate. The Two-Column Aerosol Project, or TCAP, was designed to provide a detailed set of observations to tackle this area of unknowns. Led by PNNL atmospheric scientist Larry Berg, ARM's Climate Research Facility was deployed in Cape Cod, Massachusetts for the 12-month duration of TCAP, which came to a close in June 2013. "We are developing new tools to look at particle chemistry, like our mass spectrometer used in TCAP that can tell us the individual chemical composition of an aerosol," said Berg. "Then, we'll run our models and compare it with the data that we have to make sure we're getting correct answers and make sure our climate models are reflecting the best information."

Low-cloud characteristics over the tropical western Pacific from ARM observations and CAM5 simulations

DOE PAGES

Chandra, Arunchandra S.; Zhang, Chidong; Klein, Stephen A.; ...

2015-09-10

Here, this study evaluates the ability of the Community Atmospheric Model version 5 (CAM5) to reproduce low clouds observed by the Atmospheric Radiation Measurement (ARM) cloud radar at Manus Island of the tropical western Pacific during the Years of Tropical Convection. Here low clouds are defined as clouds with their tops below the freezing level and bases within the boundary layer. Low-cloud statistics in CAM5 simulations and ARM observations are compared in terms of their general occurrence, mean vertical profiles, fraction of precipitating versus nonprecipitating events, diurnal cycle, and monthly time series. Other types of clouds are included to putmore » the comparison in a broader context. The comparison shows that the model overproduces total clouds and their precipitation fraction but underestimates low clouds in general. The model, however, produces excessive low clouds in a thin layer between 954 and 930 hPa, which coincides with excessive humidity near the top of the mixed layer. This suggests that the erroneously excessive low clouds stem from parameterization of both cloud and turbulence mixing. The model also fails to produce the observed diurnal cycle in low clouds, not exclusively due to the model coarse grid spacing that does not resolve Manus Island. Lastly, this study demonstrates the utility of ARM long-term cloud observations in the tropical western Pacific in verifying low clouds simulated by global climate models, illustrates issues of using ARM observations in model validation, and provides an example of severe model biases in producing observed low clouds in the tropical western Pacific.« less

The ARM Cloud Radar Simulator for Global Climate Models: A New Tool for Bridging Field Data and Climate Models

DOE PAGES

Zhang, Yuying; Xie, Shaocheng; Klein, Stephen A.; ...

2017-08-11

Clouds play an important role in Earth’s radiation budget and hydrological cycle. However, current global climate models (GCMs) have difficulties in accurately simulating clouds and precipitation. To improve the representation of clouds in climate models, it is crucial to identify where simulated clouds differ from real world observations of them. This can be difficult, since significant differences exist between how a climate model represents clouds and what instruments observe, both in terms of spatial scale and the properties of the hydrometeors which are either modeled or observed. To address these issues and minimize impacts of instrument limitations, the concept ofmore » instrument “simulators”, which convert model variables into pseudo-instrument observations, has evolved with the goal to facilitate and to improve the comparison of modeled clouds with observations. Many simulators have been (and continue to be) developed for a variety of instruments and purposes. Finally, a community satellite simulator package, the Cloud Feedback Model Intercomparison Project (CFMIP) Observation Simulator Package (COSP; Bodas-Salcedo et al. 2011), contains several independent satellite simulators and is being widely used in the global climate modeling community to exploit satellite observations for model cloud evaluation (e.g., Kay et al. 2012; Klein et al. 2013; Suzuki et al. 2013; Zhang et al. 2010).« less

The ARM Cloud Radar Simulator for Global Climate Models: A New Tool for Bridging Field Data and Climate Models

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

Zhang, Yuying; Xie, Shaocheng; Klein, Stephen A.

Clouds play an important role in Earth’s radiation budget and hydrological cycle. However, current global climate models (GCMs) have difficulties in accurately simulating clouds and precipitation. To improve the representation of clouds in climate models, it is crucial to identify where simulated clouds differ from real world observations of them. This can be difficult, since significant differences exist between how a climate model represents clouds and what instruments observe, both in terms of spatial scale and the properties of the hydrometeors which are either modeled or observed. To address these issues and minimize impacts of instrument limitations, the concept ofmore » instrument “simulators”, which convert model variables into pseudo-instrument observations, has evolved with the goal to facilitate and to improve the comparison of modeled clouds with observations. Many simulators have been (and continue to be) developed for a variety of instruments and purposes. Finally, a community satellite simulator package, the Cloud Feedback Model Intercomparison Project (CFMIP) Observation Simulator Package (COSP; Bodas-Salcedo et al. 2011), contains several independent satellite simulators and is being widely used in the global climate modeling community to exploit satellite observations for model cloud evaluation (e.g., Kay et al. 2012; Klein et al. 2013; Suzuki et al. 2013; Zhang et al. 2010).« less

Evaluation of WRF Model Against Satellite and Field Measurements During ARM March 2000 IOP

NASA Astrophysics Data System (ADS)

Wu, J.; Zhang, M.

2003-12-01

Meso-scale WRF model is employed to simulate the organization of clouds related with the cyclogenesis occurred during March 1-4, 2000 over ARM SGP CART site. Qualitative comparisons of simulated clouds with GOES8 satellite images show that the WRF model can capture the main features of clouds related with the cyclogenesis. The simulated precipitation patterns also match the Radar reflectivity images well. Further evaluation of the simulated features on GCM grid-scale is conducted against ARM field measurements. The evaluation shows that the evolutions of the simulated state fields such as temperature and moisture, the simulated wind fields and the derived large-scale temperature and moisture tendencies closely follow the observed patterns. These results encourages us to use meso-scale WRF model as a tool to verify the performance of GCMs in simulating cloud feedback processes related with the frontal clouds such that we can test and validate the current cloud parameterizations in climate models, and make possible improvements to different components of current cloud parameterizations in GCMs.

Agricultural Practice and Regional Climate Interactions in a Coupled Land Surface Mesoscale Model

NASA Astrophysics Data System (ADS)

Cooley, H. S.; Riley, W. J.; Torn, M. S.

2003-12-01

Regional climate affects the timing of harvest for rain-fed crops. In response to dry conditions, for example, farmers may harvest crops earlier than they do under wet conditions. This removal of vegetation alters the land surface characteristics and may, in turn, affect regional climate conditions. We studied the dynamic relationship between land use practice, i.e. winter wheat harvest, and regional climate by applying a coupled climate (MM5) and land-surface (LSM1) model to the ARM-CART region of the Southern Great Plains. We compared early and late harvest scenarios, with winter wheat harvested on June 5 and July 5, respectively. Winter wheat is grown in a fairly uniform belt that accounts for 20% of the total land area over the domain of the ARM-CART. Results showed that harvest dramatically affects energy, momentum, and water fluxes. Regionally-averaged, 2 m air temperatures were 0.5-1\\deg C warmer in the early- compared to late-harvest case, with peak warming of 5\\deg C centered over the harvested area. Soils in the harvested area were drier and warmer in the top 10 cm. Near-surface soil water-filled pore space was reduced by 7% across the region, with a peak drying of 22% centered over the harvested area. Soils were up to 10\\deg C warmer, with area-averaged warming of ~0.6\\deg C at mid-day two weeks after harvest. Differences between scenarios were greatest during an initial two-week dry period. A subsequent wet period greatly reduced these differences.

ARM - Midlatitude Continental Convective Clouds

DOE Data Explorer

Jensen, Mike; Bartholomew, Mary Jane; Genio, Anthony Del; Giangrande, Scott; Kollias, Pavlos

2012-01-19

Convective processes play a critical role in the Earth's energy balance through the redistribution of heat and moisture in the atmosphere and their link to the hydrological cycle. Accurate representation of convective processes in numerical models is vital towards improving current and future simulations of Earths climate system. Despite improvements in computing power, current operational weather and global climate models are unable to resolve the natural temporal and spatial scales important to convective processes and therefore must turn to parameterization schemes to represent these processes. In turn, parameterization schemes in cloud-resolving models need to be evaluated for their generality and application to a variety of atmospheric conditions. Data from field campaigns with appropriate forcing descriptors have been traditionally used by modelers for evaluating and improving parameterization schemes.

ARM - Midlatitude Continental Convective Clouds (comstock-hvps)

DOE Data Explorer

Jensen, Mike; Comstock, Jennifer; Genio, Anthony Del; Giangrande, Scott; Kollias, Pavlos

2012-01-06

Convective processes play a critical role in the Earth's energy balance through the redistribution of heat and moisture in the atmosphere and their link to the hydrological cycle. Accurate representation of convective processes in numerical models is vital towards improving current and future simulations of Earths climate system. Despite improvements in computing power, current operational weather and global climate models are unable to resolve the natural temporal and spatial scales important to convective processes and therefore must turn to parameterization schemes to represent these processes. In turn, parameterization schemes in cloud-resolving models need to be evaluated for their generality and application to a variety of atmospheric conditions. Data from field campaigns with appropriate forcing descriptors have been traditionally used by modelers for evaluating and improving parameterization schemes.

Gridding Cloud and Irradiance to Quantify Variability at the ARM Southern Great Plains Site

NASA Astrophysics Data System (ADS)

Riihimaki, L.; Long, C. N.; Gaustad, K.

2017-12-01

Ground-based radiometers provide the most accurate measurements of surface irradiance. However, geometry differences between surface point measurements and large area climate model grid boxes or satellite-based footprints can cause systematic differences in surface irradiance comparisons. In this work, irradiance measurements from a network of ground stations around Kansas and Oklahoma at the US Department of Energy Atmospheric Radiation Measurement (ARM) Southern Great Plains facility are examined. Upwelling and downwelling broadband shortwave and longwave radiometer measurements are available at each site as well as surface meteorological measurements. In addition to the measured irradiances, clear sky irradiance and cloud fraction estimates are analyzed using well established methods based on empirical fits to measured clear sky irradiances. Measurements are interpolated onto a 0.25 degree latitude and longitude grid using a Gaussian weight scheme in order to provide a more accurate statistical comparison between ground measurements and a larger area such as that used in climate models, plane parallel radiative transfer calculations, and other statistical and climatological research. Validation of the gridded product will be shown, as well as analysis that quantifies the impact of site location, cloud type, and other factors on the resulting surface irradiance estimates. The results of this work are being incorporated into the Surface Cloud Grid operational data product produced by ARM, and will be made publicly available for use by others.

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

Penner, Joyce E.; Zhou, Cheng

Observation-based studies have shown that the aerosol cloud lifetime effect or the increase of cloud liquid water path (LWP) with increased aerosol loading may have been overestimated in climate models. Here, we simulate shallow warm clouds on 05/27/2011 at the Southern Great Plains (SGP) measurement site established by Department of Energy's Atmospheric Radiation Measurement (ARM) Program using a single column version of a global climate model (Community Atmosphere Model or CAM) and a cloud resolving model (CRM). The LWP simulated by CAM increases substantially with aerosol loading while that in the CRM does not. The increase of LWP in CAMmore » is caused by a large decrease of the autoconversion rate when cloud droplet number increases. In the CRM, the autoconversion rate is also reduced, but this is offset or even outweighed by the increased evaporation of cloud droplets near cloud top, resulting in an overall decrease in LWP. Our results suggest that climate models need to include the dependence of cloud top growth and the evaporation/condensation process on cloud droplet number concentrations.« less

Campaign datasets for Observations and Modeling of the Green Ocean Amazon (GOAMAZON)

DOE Data Explorer

Martin,Scot; Mei,Fan; Alexander,Lizabeth; Artaxo,Paulo; Barbosa,Henrique; Bartholomew,Mary Jane; Biscaro,Thiago; Buseck,Peter; Chand,Duli; Comstock,Jennifer; Dubey,Manvendra; Godstein,Allen; Guenther,Alex; Hubbe,John; Jardine,Kolby; Jimenez,Jose-Luis; Kim,Saewung; Kuang,Chongai; Laskin,Alexander; Long,Chuck; Paralovo,Sarah; Petaja,Tuukka; Powers,Heath; Schumacher,Courtney; Sedlacek,Arthur; Senum,Gunnar; Smith,James; Shilling,John; Springston,Stephen; Thayer,Mitchell; Tomlinson,Jason; Wang,Jian; Xie,Shaocheng

2016-05-30

The hydrologic cycle of the Amazon Basin is one of the primary heat engines of the Southern Hemisphere. Any accurate climate model must succeed in a good description of the Basin, both in its natural state and in states perturbed by regional and global human activities. At the present time, however, tropical deep convection in a natural state is poorly understood and modeled, with insufficient observational data sets for model constraint. Furthermore, future climate scenarios resulting from human activities globally show the possible drying and the eventual possible conversion of rain forest to savanna in response to global climate change. Based on our current state of knowledge, the governing conditions of this catastrophic change are not defined. Human activities locally, including the economic development activities that are growing the population and the industry within the Basin, also have the potential to shift regional climate, most immediately by an increment in aerosol number and mass concentrations, and the shift is across the range of values to which cloud properties are most sensitive. The ARM Climate Research Facility in the Amazon Basin seeks to understand aerosol and cloud life cycles, particularly the susceptibility to cloud aerosol precipitation interactions, within the Amazon Basin.

The DOE ARM Aerial Facility

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

Schmid, Beat; Tomlinson, Jason M.; Hubbe, John M.

2014-05-01

The Department of Energy Atmospheric Radiation Measurement (ARM) Program is a climate research user facility operating stationary ground sites that provide long-term measurements of climate relevant properties, mobile ground- and ship-based facilities to conduct shorter field campaigns (6-12 months), and the ARM Aerial Facility (AAF). The airborne observations acquired by the AAF enhance the surface-based ARM measurements by providing high-resolution in-situ measurements for process understanding, retrieval-algorithm development, and model evaluation that are not possible using ground- or satellite-based techniques. Several ARM aerial efforts were consolidated into the AAF in 2006. With the exception of a small aircraft used for routinemore » measurements of aerosols and carbon cycle gases, AAF at the time had no dedicated aircraft and only a small number of instruments at its disposal. In this "virtual hangar" mode, AAF successfully carried out several missions contracting with organizations and investigators who provided their research aircraft and instrumentation. In 2009, AAF started managing operations of the Battelle-owned Gulfstream I (G-1) large twin-turboprop research aircraft. Furthermore, the American Recovery and Reinvestment Act of 2009 provided funding for the procurement of over twenty new instruments to be used aboard the G-1 and other AAF virtual-hangar aircraft. AAF now executes missions in the virtual- and real-hangar mode producing freely available datasets for studying aerosol, cloud, and radiative processes in the atmosphere. AAF is also engaged in the maturation and testing of newly developed airborne sensors to help foster the next generation of airborne instruments.« less

On building methodological and theoretical frameworks to examine the interrelationships between environmental change and armed conflict

NASA Astrophysics Data System (ADS)

Van Den Hoek, J.

2014-12-01

Relationships between environmental change and armed conflict have long been studied. Sometimes referred to as 'warfare' or 'conflict' ecology, much of this scholarship has come in response to local-level perceptions of landscape or livelihood changes that result from regional armed conflict. However, such studies have, first, typically focused on spatiotemporally acute and readily detectable environmental change, like deforestation, to the exclusion of protracted and more subtle environmental changes, like agricultural degradation; second, been limited to situational conflicts or circumstances, thereby inhibiting broader theoretical development; and, third, often only considered the environmental consequences rather than the environmental or climatic circumstances that may contribute to conflict. As a result, there is little opportunity for methodological or theoretical cohesion between studies. In this presentation, I synthesize findings from three case studies examining the interrelationships between agricultural change and armed conflict in the semi-arid landscapes of northwest Pakistan, Palestine, and southern Syria. Using coarse through very high resolution remotely sensed imagery, socio-economic and demographic data, conflict databases, open-source programming, and building on theoretical underpinnings of political ecology and conflict studies, I present methods and modeling approaches that aid in overcoming data scarcity and disparity between scales of analysis and integrate environmental and conflict data in spatiotemporally explicit ways. Results from these case studies illuminate the interrelationships between both protracted and acute agricultural change and armed conflict, and have broad relevance for understanding the means by which environment, conflict, and livelihoods are linked, a nexus that will only become tighter with the advance of global climate change.

DOE ASR Final Report on “Use of ARM Observations to Investigate the Role of Tropical Radiative Processes and Cloud Radiative Effects in Climate Simulations”

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

Fu, Qiang; Comstock, Jennifer

The overall objective of this ASR funded project is to investigate the role of cloud radiative effects, especially those associated with tropical thin cirrus clouds in the tropical tropopause layer, by analyzing the ARM observations combined with numerical models. In particular, we have processed and analyzed the observations from the Raman lidar at the ARM SGP and TWP sites. In the tenure of the project (8/15/2013 – 8/14/2016 and with a no-cost extension to 8/14/2017), we have been concentrating on (i) developing an automated feature detection scheme of clouds and aerosols for the ARM Raman lidar; (ii) developing an automatedmore » retrieval of cloud and aerosol extinctions for the ARM Raman lidar; (iii) investigating cloud radiative effects based on the observations on the simulated temperatures in the tropical tropopause layer using a radiative-convective model; and (iv) examining the effect of changes of atmospheric composition on the tropical lower-stratospheric temperatures. In addition, we have examined the biases in the CALIPSO-inferred aerosol direct radiative effects using ground-based Raman lidars at the ARM SGP and TWP sites, and estimated the impact of lidar detection sensitivity on assessing global aerosol direct radiative effects. We have also investigated the diurnal cycle of clouds and precipitation at the ARM site using the cloud radar observations along with simulations from the multiscale modeling framework. The main results of our research efforts are reported in the six referred journal publications that acknowledge the DOE Grant DE-SC0010557.« less

Machine Learing Applications on a Radar Wind Profiler Deployment During the ARM GoAmazon2014/5 Campaign

NASA Astrophysics Data System (ADS)

Giangrande, S. E.; WANG, D.; Hardin, J. C.; Mitchell, J.

2017-12-01

As part of the 2 year Department of Energy Atmospheric Radiation Measurement (ARM) Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) campaign, the ARM Mobile Facility (AMF) collected a unique set of observations in a region of strong climatic significance near Manacapuru, Brazil. An important example for the beneficial observational record obtained by ARM during this campaign was that of the Radar Wind Profiler (RWP). This dataset has been previously documented for providing critical convective cloud vertical air velocity retrievals and precipitation properties (e.g., calibrated reflectivity factor Z, rainfall rates) under a wide variety of atmospheric conditions. Vertical air motion estimates to within deep convective cores such as those available from this RWP system have been previously identified as critical constraints for ongoing global climate modeling activities and deep convective cloud process studies. As an extended deployment within this `green ocean' region, the RWP site and collocated AMF surface gauge instrumentation experienced a unique hybrid of tropical and continental precipitation conditions, including multiple wet and dry season precipitation regimes, convective and organized stratiform storm dynamics and contributions to rainfall accumulation, pristine aerosol conditions of the locale, as well as the effects of the Manaus, Brazil, mega city pollution plume. For hydrological applications and potential ARM products, machine learning methods developed using this dataset are explored to demonstrate advantages in geophysical retrievals when compared to traditional methods. Emphasis is on performance improvements when providing additional information on storm structure and regime or echo type classifications. Since deep convective cloud dynamic insights (core updraft/downdraft properties) are difficult to obtain directly by conventional radars that also observe radar reflectivity factor profiles similar to RWP systems, we also consider possible machine learning applications to inform on (statistical) proxy convective relationships between observed convective core dynamics and radar microphysical properties that are otherwise not easily related by clear physical process paths using existing radar networks.

Model-Observation "Data Cubes" for the DOE Atmospheric Radiation Measurement Program's LES ARM Symbiotic Simulation and Observation (LASSO) Workflow

NASA Astrophysics Data System (ADS)

Vogelmann, A. M.; Gustafson, W. I., Jr.; Toto, T.; Endo, S.; Cheng, X.; Li, Z.; Xiao, H.

2015-12-01

The Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facilities' Large-Eddy Simulation (LES) ARM Symbiotic Simulation and Observation (LASSO) Workflow is currently being designed to provide output from routine LES to complement its extensive observations. The modeling portion of the LASSO workflow is presented by Gustafson et al., which will initially focus on shallow convection over the ARM megasite in Oklahoma, USA. This presentation describes how the LES output will be combined with observations to construct multi-dimensional and dynamically consistent "data cubes", aimed at providing the best description of the atmospheric state for use in analyses by the community. The megasite observations are used to constrain large-eddy simulations that provide a complete spatial and temporal coverage of observables and, further, the simulations also provide information on processes that cannot be observed. Statistical comparisons of model output with their observables are used to assess the quality of a given simulated realization and its associated uncertainties. A data cube is a model-observation package that provides: (1) metrics of model-observation statistical summaries to assess the simulations and the ensemble spread; (2) statistical summaries of additional model property output that cannot be or are very difficult to observe; and (3) snapshots of the 4-D simulated fields from the integration period. Searchable metrics are provided that characterize the general atmospheric state to assist users in finding cases of interest, such as categorization of daily weather conditions and their specific attributes. The data cubes will be accompanied by tools designed for easy access to cube contents from within the ARM archive and externally, the ability to compare multiple data streams within an event as well as across events, and the ability to use common grids and time sampling, where appropriate.

Assessing Spectral Shortwave Cloud Observations at the Southern Great Plains Facility

NASA Technical Reports Server (NTRS)

McBride, P. J.; Marshak, A.; Wiscombe, W. J.; Flynn, C. J.; Vogelmann, A. M.

2012-01-01

The Atmospheric Radiation Measurement (ARM) program (now Atmospheric System Research) was established, in part, to improve radiation models so that they could be used reliably to compute radiation fluxes through the atmosphere, given knowledge of the surface albedo, atmospheric gases, and the aerosol and cloud properties. Despite years of observations, discrepancies still exist between radiative transfer models and observations, particularly in the presence of clouds. Progress has been made at closing discrepancies in the spectral region beyond 3 micron, but the progress lags at shorter wavelengths. Ratios of observed visible and near infrared cloud albedo from aircraft and satellite have shown both localized and global discrepancies between model and observations that are, thus far, unexplained. The capabilities of shortwave surface spectrometry have been improved in recent years at the Southern Great Plains facility (SGP) of the ARM Climate Research Facility through the addition of new instrumentation, the Shortwave Array Spectroradiometer, and upgrades to existing instrumentation, the Shortwave Spectroradiometer and the Rotating Shadowband Spectroradiometer. An airborne-based instrument, the HydroRad Spectroradiometer, was also deployed at the ARM site during the Routine ARM Aerial Facility Clouds with Low Optical Water Depths (CLOWD) Optical Radiative Observations (RACORO) field campaign. Using the new and upgraded spectral observations along with radiative transfer models, cloud scenes at the SGP are presented with the goal of characterizing the instrumentation and the cloud fields themselves.

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

Giangrande, Scott E.; Feng, Zhe; Jensen, Michael P.

Routine cloud, precipitation and thermodynamic observations collected by the Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF) and Aerial Facility (AAF) during the 2-year US Department of Energy (DOE) ARM Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) campaign are summarized. These observations quantify the diurnal to large-scale thermodynamic regime controls on the clouds and precipitation over the undersampled, climatically important Amazon basin region. The extended ground deployment of cloud-profiling instrumentation enabled a unique look at multiple cloud regimes at high temporal and vertical resolution. This longer-term ground deployment, coupled with two short-term aircraft intensive observing periods, allowed new opportunitiesmore » to better characterize cloud and thermodynamic observational constraints as well as cloud radiative impacts for modeling efforts within typical Amazon wet and dry seasons.« less

Why do general circulation models overestimate the aerosol cloud lifetime effect? A case study comparing CAM5 and a CRM

NASA Astrophysics Data System (ADS)

Zhou, Cheng; Penner, Joyce E.

2017-01-01

Observation-based studies have shown that the aerosol cloud lifetime effect or the increase of cloud liquid water path (LWP) with increased aerosol loading may have been overestimated in climate models. Here, we simulate shallow warm clouds on 27 May 2011 at the southern Great Plains (SGP) measurement site established by the Department of Energy's (DOE) Atmospheric Radiation Measurement (ARM) program using a single-column version of a global climate model (Community Atmosphere Model or CAM) and a cloud resolving model (CRM). The LWP simulated by CAM increases substantially with aerosol loading while that in the CRM does not. The increase of LWP in CAM is caused by a large decrease of the autoconversion rate when cloud droplet number increases. In the CRM, the autoconversion rate is also reduced, but this is offset or even outweighed by the increased evaporation of cloud droplets near the cloud top, resulting in an overall decrease in LWP. Our results suggest that climate models need to include the dependence of cloud top growth and the evaporation/condensation process on cloud droplet number concentrations.

Stratocumulus Precipitation and Entrainment Experiment (SPEE) Field Campaign Report

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

Albrecht, Bruce; Ghate, Virendra; CADeddu, Maria

2016-06-01

The scientific focus of this project was to examine precipitation and entrainment processes in marine stratocumulus clouds. The entrainment studies focused on characterizing cloud turbulence at cloud top using Doppler cloud radar observations. The precipitation studies focused on characterizing the precipitation and the macroscopic properties (cloud thickness, and liquid water path) of the clouds. This project will contribute to the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s overall objective of providing the remote-sensing observations needed to improve the representation of key cloud processes in climate models. It will be of direct relevance to the componentsmore » of ARM dealing with entrainment and precipitation processes in stratiform clouds. Further, the radar observing techniques that will be used in this study were developed using ARM Southern Great Plains (SGP) facility observations under Atmospheric System Research (ASR) support. The observing systems operating automatously from a site located just north of the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) aircraft hangar in Marina, California during the period of 1 May to 4 November 2015 included: 1. Microwave radiometer: ARM Microwave Radiometer, 3-Channel (MWR3C) with channels centered at 23.834, 30, and 89 GHz; supported by Dr. Maria Cadeddu. 2. Cloud Radar: CIRPAS 95 GHz Frequency Modulated Continuous Wave (FMCW) Cloud Radar (Centroid Frequency Chirp Rate [CFCR]); operations overseen by Drs. Ghate and Albrecht. 3. Ceilometer: Vaisala CK-14; operations overseen by Drs. Ghate and Albrecht.« less

Dimensions of operational stress and forms of unacceptable risk taking with small arms and munitions.

PubMed

Ben-Shalom, Uzi

2015-01-01

Accidents with small arms and munitions during deployment is a significant safety concern for leaders and safety specialists in combat units. Operational stress may lead to forms of unacceptable risk taking with small arms that may underlie some of these accidents. The present research studied the correlation between two dimensions of operational stress, two forms of risk taking with small arms among combat unit soldiers and possible mediators. The dimensions of operational threat, negative affect and personality profile from the EPQ-R-S were predictors; "exaggerated preparedness" and "risky games with small arms and munitions" were dependent variables; safety climate of the platoon served as a mediator variable. The participants were 461 compulsory service combat soldiers in 31 companies. This field study was conducted during period of top security alert. The results reveal that perceived threat is indeed correlated with exaggerated operational preparedness whereas general emotional state was correlated with risky games with small arms. Safety climate mediated only the correlation between general emotional state and risky games with small arms and munitions. Preparedness and risky games were predicted by the interaction of Psychoticism and the Lie Scale from the EPQ-R-S. The results may enhance the efforts in reducing risk taking and prevention of accidents with small arms and munitions during and following deployment.

Department of Energy Arm Facilities on the North Slope of Alaska and Plans for a North Slope "Mega-Site"

NASA Astrophysics Data System (ADS)

Ivey, M.; Verlinde, J.

2014-12-01

The U.S. Department of Energy (DOE), through its scientific user facility, the Atmospheric Radiation Measurement (ARM) Climate Research Facility, provides scientific infrastructure and data to the international Arctic research community via its research sites located on the North Slope of Alaska. The DOE ARM Program has operated an atmospheric measurement facility in Barrow, Alaska, since 1998. Major upgrades to this facility, including scanning radars, were added in 2010. Facilities and infrastructure to support operations of unmanned aerial systems for science missions in the Arctic and North Slope of Alaska were established at Oliktok Point Alaska in 2013. Tethered instrumented balloons will be used in the near future to make measurements of clouds in the boundary layer including mixed-phase clouds. The Atmospheric Radiation Measurement (ARM) Climate Research Facility is implementing "mega-sites" at the Southern Great Plains and North Slope of Alaska sites. Two workshops were held to gather input from the scientific community on these mega-sites. The NSA workshop was held September 10 and 11 in the Washington DC area. The workshops included discussions of additional profiling remote sensors, detailed measurements of the land-atmosphere interface, aerial operations to link the Barrow and Oliktok sites, unmanned aerial system measurements, and routine large eddy simulation model runs. The "mega-sites" represent a significant new scientific and infrastructure investment by DOE Office of Science, Office of Biological and Environmental Research. This poster will present information on plans for a North Slope "Megasite" as well as new opportunities for members of the arctic research community to make atmospheric measurements using unmanned aerial systems or tethered balloons in conjunction with the DOE ARM facilities on the North Slope of Alaska.

ACME-III and ACME-IV Final Campaign Reports

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

Biraud, S. C.

2016-01-01

The goals of the Atmospheric Radiation Measurement (ARM) Climate Research Facility’s third and fourth Airborne Carbon Measurements (ACME) field campaigns, ACME-III and ACME-IV, are: 1) to measure and model the exchange of CO 2, water vapor, and other greenhouse gases by the natural, agricultural, and industrial ecosystems of the Southern Great Plains (SGP) region; 2) to develop quantitative approaches to relate these local fluxes to the concentration of greenhouse gases measured at the Central Facility tower and in the atmospheric column above the ARM SGP Central Facility, 3) to develop and test bottom-up measurement and modeling approaches to estimate regionalmore » scale carbon balances, and 4) to develop and test inverse modeling approaches to estimate regional scale carbon balance and anthropogenic sources over continental regions. Regular soundings of the atmosphere from near the surface into the mid-troposphere are essential for this research.« less

Cloud characteristics, thermodynamic controls and radiative impacts during the Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) experiment

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

Giangrande, Scott E.; Feng, Zhe; Jensen, Michael P.

Routine cloud, precipitation and thermodynamic observations collected by the Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF) and Aerial Facility (AAF) during the 2-year US Department of Energy (DOE) ARM Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) campaign are summarized. These observations quantify the diurnal to large-scale thermodynamic regime controls on the clouds and precipitation over the undersampled, climatically important Amazon basin region. The extended ground deployment of cloud-profiling instrumentation enabled a unique look at multiple cloud regimes at high temporal and vertical resolution. This longer-term ground deployment, coupled with two short-term aircraft intensive observing periods, allowed new opportunitiesmore » to better characterize cloud and thermodynamic observational constraints as well as cloud radiative impacts for modeling efforts within typical Amazon wet and dry seasons.« less

Cloud characteristics, thermodynamic controls and radiative impacts during the Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) experiment

DOE PAGES

Giangrande, Scott E.; Feng, Zhe; Jensen, Michael P.; ...

2017-12-06

Routine cloud, precipitation and thermodynamic observations collected by the Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF) and Aerial Facility (AAF) during the 2-year US Department of Energy (DOE) ARM Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) campaign are summarized. These observations quantify the diurnal to large-scale thermodynamic regime controls on the clouds and precipitation over the undersampled, climatically important Amazon basin region. The extended ground deployment of cloud-profiling instrumentation enabled a unique look at multiple cloud regimes at high temporal and vertical resolution. This longer-term ground deployment, coupled with two short-term aircraft intensive observing periods, allowed new opportunitiesmore » to better characterize cloud and thermodynamic observational constraints as well as cloud radiative impacts for modeling efforts within typical Amazon wet and dry seasons.« less

Diagnosing causes of cloud parameterization deficiencies using ARM measurements over SGP site

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

Wu, W.; Liu, Y.; Betts, A. K.

2010-03-15

Decade-long continuous surface-based measurements at Great Southern Plains (SGP) collected by the US Department of Energy’s Atmospheric Radiation Measurement (ARM) Climate Research Facility are first used to evaluate the three major reanalyses (i.e., ERA-Interim, NCEP/NCAR Reanalysis I and NCEP/DOE Reanalysis II) to identify model biases in simulating surface shortwave cloud forcing and total cloud fraction. The results show large systematic lower biases in the modeled surface shortwave cloud forcing and cloud fraction from all the three reanalysis datasets. Then we focus on diagnosing the causes of these model biases using the Active Remote Sensing of Clouds (ARSCL) products (e.g., verticalmore » distribution of cloud fraction, cloud-base and cloud-top heights, and cloud optical depth) and meteorological measurements (temperature, humidity and stability). Efforts are made to couple cloud properties with boundary processes in the diagnosis.« less

Description of the LASSO Alpha 1 Release

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

Gustafson, William I.; Vogelmann, Andrew M.; Cheng, Xiaoping

The Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility began a pilot project in May 2015 to design a routine, high-resolution modeling capability to complement ARM’s extensive suite of measurements. This modeling capability has been named the Large-Eddy Simulation (LES) ARM Symbiotic Simulation and Observation (LASSO) project. The availability of LES simulations with concurrent observations will serve many purposes. LES helps bridge the scale gap between DOE ARM observations and models, and the use of routine LES adds value to observations. It provides a self-consistent representation of the atmosphere and a dynamical context for the observations. Further,more » it elucidates unobservable processes and properties. LASSO will generate a simulation library for researchers that enables statistical approaches beyond a single-case mentality. It will also provide tools necessary for modelers to reproduce the LES and conduct their own sensitivity experiments. Many different uses are envisioned for the combined LASSO LES and observational library. For an observationalist, LASSO can help inform instrument remote-sensing retrievals, conduct Observation System Simulation Experiments (OSSEs), and test implications of radar scan strategies or flight paths. For a theoretician, LASSO will help calculate estimates of fluxes and co-variability of values, and test relationships without having to run the model yourself. For a modeler, LASSO will help one know ahead of time which days have good forcing, have co-registered observations at high-resolution scales, and have simulation inputs and corresponding outputs to test parameterizations. Further details on the overall LASSO project are available at http://www.arm. gov/science/themes/lasso.« less

Vegetation change, malnutrition and violence in the Horn of Africa

NASA Astrophysics Data System (ADS)

Rowhani, P.; Degomme, O.; Linderman, M.; Guha-Sapir, D.; Lambin, E.

2008-12-01

In certain circumstances, climate change in association with a broad range of social factors may increase the risk of famines and subsequently, violent conflict. The impacts of climate change on society will be experienced both through changes in mean conditions over long time periods and through increases in extreme events. Recent studies have shown the historical effects of long term climate change on societies and the importance of short term climatic triggers on armed conflict. However, most of these studies are at the state level ignoring local conditions. Here we use detailed information extracted from wide-swath satellite data (MODIS) to analyze the impact of climate variability change on malnutrition and violent conflict. More specifically, we perform multivariate logistic regression analysis in order to explain the geographical distribution of malnutrition and conflict in the Horn of Africa on a sub-national level. This region, constituted by several unstable and poor states, has been affected by droughts, floods, famines, and violence in the past few years. Three commonly used nutrition and mortality indicators are used to characterize the health situation (CE-DAT database). To map violence we use the georeferenced Armed Conflicts dataset developed by the Center for the Study of Civil War. Explanatory variables include several socio-economic variables and environmental variables characterizing land degradation, vegetation activity, and interannual variability in land-surface conditions. First results show that interannual variability in land-surface conditions is associated with malnutrition but not with armed conflict. Furthermore, land degradation seems not to be associated with either malnutrition or armed conflict.

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

Jensen, Michael; Kollias, Pavlos; Giangrande, Scott

The Mid-latitude Continental Convective Clouds Experiment (MC3E) took place from April 22 through June 6, 2011, centered at the ARM Southern Great Plains site (http://www.arm.gov/sites/sgp) in northcentral Oklahoma. MC3E was a collaborative effort between the ARM Climate Research Facility and the National Aeronautics and Space Administration’s (NASA’s) Global Precipitation Measurement (GPM) mission Ground Validation (GV) program. The campaign leveraged the largest ground-based observing infrastructure available in the central United States, including recent upgrades through the American Recovery and Reinvestment Act of 2009, combined with an extensive sounding array, remote sensing and in situ aircraft observations, and additional radar and inmore » situ precipitation instrumentation. The overarching goal of the campaign was to provide a three-dimensional characterization of convective clouds and precipitation for the purpose of improving the representation of convective lifecycle in atmospheric models and the reliability of satellite-based retrievals of precipitation.« less

Arm-Locking with the GRACE Follow-On Laser Ranging Instrument

NASA Technical Reports Server (NTRS)

Thorpe, James Ira; Mckenzie, Kirk

2016-01-01

Arm-locking is a technique for stabilizing the frequency of a laser in an inter-spacecraft interferometer by using the spacecraft separation as the frequency reference. A candidate technique for future space-based gravitational wave detectors such as the Laser Interferometer Space Antenna (LISA), arm-locking has been extensive studied in this context through analytic models, time-domain simulations, and hardware-in-the-loop laboratory demonstrations. In this paper we show the Laser Ranging Instrument flying aboard the upcoming Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) mission provides an appropriate platform for an on-orbit demonstration of the arm-locking technique. We describe an arm-locking controller design for the GRACE-FO system and a series of time-domain simulations that demonstrate its feasibility. We conclude that it is possible to achieve laser frequency noise suppression of roughly two orders of magnitude around a Fourier frequency of 1Hz with conservative margins on the system's stability. We further demonstrate that `pulling' of the master laser frequency due to fluctuating Doppler shifts and lock acquisition transients is less than 100MHz over several GRACE-FO orbits. These findings motivate further study of the implementation of such a demonstration.

Arm locking with the GRACE follow-on laser ranging interferometer

NASA Astrophysics Data System (ADS)

Thorpe, James Ira; McKenzie, Kirk

2016-02-01

Arm locking is a technique for stabilizing the frequency of a laser in an interspacecraft interferometer by using the spacecraft separation as the frequency reference. A candidate technique for future space-based gravitational wave detectors such as the Laser Interferometer Space Antenna, arm locking has been extensive studied in this context through analytic models, time-domain simulations, and hardware-in-the-loop laboratory demonstrations. In this paper we show the laser ranging interferometer instrument flying aboard the upcoming Gravity Recovery and Climate Experiment follow-on (GRACE-FO) mission provides an appropriate platform for an on-orbit demonstration of the arm-locking technique. We describe an arm-locking controller design for the GRACE-FO system and a series of time-domain simulations that demonstrate its feasibility. We conclude that it is possible to achieve laser frequency noise suppression of roughly 2 orders of magnitude around a Fourier frequency of 1 Hz with conservative margins on the system's stability. We further demonstrate that "pulling" of the master laser frequency due to fluctuating Doppler shifts and lock acquisition transients is less than 100 MHz over several GRACE-FO orbits. These findings motivate further study of the implementation of such a demonstration.

Tool to assess contents of ARM surface meteorology network netCDF files

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

Staudt, A.; Kwan, T.; Tichler, J.

The Atmospheric Radiation Measurement (ARM) Program, supported by the US Department of Energy, is a major program of atmospheric measurement and modeling designed to improve the understanding of processes and properties that affect atmospheric radiation, with a particular focus on the influence of clouds and the role of cloud radiative feedback in the climate system. The ARM Program will use three highly instrumented primary measurement sites. Deployment of instrumentation at the first site, located in the Southern Great Plains of the United States, began in May of 1992. The first phase of deployment at the second site in the Tropicalmore » Western Pacific is scheduled for late in 1995. The third site will be in the North Slope of Alaska and adjacent Arctic Ocean. To meet the scientific objectives of ARM, observations from the ARM sites are combined with data from other sources; these are called external data. Among these external data sets are surface meteorological observations from the Oklahoma Mesonet, a Kansas automated weather network, the Wind Profiler Demonstration Network (WPDN), and the National Weather Service (NWS) surface stations. Before combining these data with the Surface Meteorological Observations Station (SMOS) ARM data, it was necessary to assess the contents and quality of both the ARM and the external data sets. Since these data sets had previously been converted to netCDF format for use by the ARM Science Team, a tool was written to assess the contents of the netCDF files.« less

Use of ARM observations and numerical models to determine radiative and latent heating profiles of mesoscale convective systems for general circulation models

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

Robert A. Houze, Jr.

2013-11-13

We examined cloud radar data in monsoon climates, using cloud radars at Darwin in the Australian monsoon, on a ship in the Bay of Bengal in the South Asian monsoon, and at Niamey in the West African monsoon. We followed on with a more in-depth study of the continental MCSs over West Africa. We investigated whether the West African anvil clouds connected with squall line MCSs passing over the Niamey ARM site could be simulated in a numerical model by comparing the observed anvil clouds to anvil structures generated by the Weather Research and Forecasting (WRF) mesoscale model at highmore » resolution using six different ice-phase microphysical schemes. We carried out further simulations with a cloud-resolving model forced by sounding network budgets over the Niamey region and over the northern Australian region. We have devoted some of the effort of this project to examining how well satellite data can determine the global breadth of the anvil cloud measurements obtained at the ARM ground sites. We next considered whether satellite data could be objectively analyzed to so that their large global measurement sets can be systematically related to the ARM measurements. Further differences were detailed between the land and ocean MCS anvil clouds by examining the interior structure of the anvils with the satellite-detected the CloudSat Cloud Profiling Radar (CPR). The satellite survey of anvil clouds in the Indo-Pacific region was continued to determine the role of MCSs in producing the cloud pattern associated with the MJO.« less

Evaluation of Cirrus Cloud Simulations Using ARM Data - Development of a Case Study Data Set

NASA Technical Reports Server (NTRS)

O'C.Starr, David; Demoz, Belay; Lare, Andrew; Poellot, Michael; Sassen, Kenneth; Heymsfield, Andrew; Brown, Philip; Mace, Jay; Einaudi, Franco (Technical Monitor)

2001-01-01

Cloud-resolving models (CRMs) provide an effective linkage in terms of parameters and scales between observations and the parametric treatments of clouds in global climate models (GCMs). They also represent the best understanding of the physical processes acting to determine cloud system lifecycle. The goal of this project is to improve state-of-the-art CRMs used for studies of cirrus clouds and to establish a relative calibration with GCMs through comparisons among CRMs, single column model (SCM) versions of the GCMs, and observations. This project will compare and evaluate a variety of CRMs and SCMs, under the auspices of the GEWEX Cloud Systems Study (GCSS) Working Group on Cirrus Cloud Systems (WG2), using ARM data acquired at the Southern Great Plains (SGP) site. This poster will report on progress in developing a suitable WG2 case study data set based on the September 26, 1996 ARM IOP case - the Hurricane Nora outflow case. The environmental data (input) will be described as well as the wealth of validating cloud observations. We plan to also show results of preliminary simulations. The science questions to be addressed derive significantly from results of the GCSS WG2 cloud model comparison projects, which will be briefly summarized.

ARM Climate Research Facility Quarterly Value-Added Product Report

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

Sivaraman, C.

The purpose of this report is to provide a concise status update for Value-Added Products (VAPs) implemented by the Atmospheric Radiation Measurement (ARM) Climate Research Facility. The report is divided into the following sections: (1) new VAPs for which development has begun; (2) progress on existing VAPs; (3) future VAPs that have been recently approved; (4) other work that leads to a VAP; (5) top requested VAPs from the ARM Data Archive; and (6) a summary of VAP and data releases to production and evaluation. New information is highlighted in blue text. New information about processed data by the developermore » is highlighted in red text. The upcoming milestones and dates are highlighted in green.« less

A 15 year legacy of cloud and atmosphere observations in Barrow, Alaska

NASA Astrophysics Data System (ADS)

Shupe, M.

2012-12-01

For the past 15 years, the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) Program has operated the North Slope of Alaska (NSA) atmospheric observatory in Barrow, Alaska. Barrow offers many valuable perspectives on the Arctic environment that complement observations at lower latitudes. Unique features of the Arctic region include cold and dry atmospheric conditions, strong annual variability in sun light, a seasonally high-reflective surface, and persistent clouds that involve mixed-phase processes. ARM's ultimate objective with its flagship observatory at the northernmost point in U.S. territory is to provide measurements that can be used to improve the understanding of these atmospheric physical and radiative properties and processes such that they can be better represented in climate models. The NSA is the most detailed and long-lasting cloud-radiation-atmosphere observatory in the Arctic, providing continuous, sophisticated measurements of climate-relevant parameters. Instrument suites include active radars and lidars at various frequencies, passive radiometers monitoring radiation in microwave, infrared, visible and ultraviolet wavelengths, meteorological towers, and sounding systems. Together these measurements are used to characterize many of the important properties of clouds, aerosols, atmospheric radiation, dynamics, thermodynamics, and the surface. The coordinated nature of these measurements offers important multi-dimensional insight into many fundamental processes linking these different elements of the climate system. Moreover, the continuous operations of the facility support these observations over the full diurnal cycle and in all seasons of the year. This presentation will highlight a number of important studies and key findings that have been facilitated by the NSA observations during the first 15 years in operation. Some of these include: a thorough documentation of clouds, their occurrence frequency, phase, microphysical properties, and impacts on surface radiation; the indirect effect of aerosols on the surface longwave radiative effects of Arctic clouds; improved measurements of low amounts of atmospheric water vapor and their impacts on atmospheric radiation; dynamical and microphysical processes that are responsible for long-lived Arctic stratiform clouds; evaluation of satellite observations in extreme and observationally-difficult regimes; and assessment of model performance for models ranging from very high resolution to climate model simulations in the Arctic. The observational legacy at Barrow continues as ARM works to expand and enhance its impact. Plans are underway to install observational capabilities at a sister location in Oliktok Point to the east of Barrow, including enhanced capabilities of tethered balloon profiling and flying unmanned aerial vehicles over the adjacent Arctic Ocean. A new set of scanning cloud and precipitation radars have recently come online at Barrow that will allow for new insights on the spatial context of measurements at Barrow, including important information on the variability of atmospheric processes associated with the coastline. And lastly, there are many opportunities for the intensive observations at Barrow to inform important regional research on permafrost and sea-ice loss, while also serving as an unmatched, long-term record for evaluating atmospheric processes in regional and global climate models.

Atmospheric radiation measurement unmanned aerospace vehicle (ARM-UAV) program

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

Bolton, W.R.

1996-11-01

ARM-UAV is part of the multi-agency U.S. Global Change Research Program and is addressing the largest source of uncertainty in predicting climatic response: the interaction of clouds and the sun`s energy in the Earth`s atmosphere. An important aspect of the program is the use of unmanned aerospace vehicles (UAVs) as the primary airborne platform. The ARM-UAV Program has completed two major flight series: The first series conducted in April, 1994, using an existing UAV (the General Atomics Gnat 750) consisted of eight highly successful flights at the DOE climate site in Oklahoma. The second series conducted in September/October, 1995, usingmore » two piloted aircraft (Egrett and Twin Otter), featured simultaneous measurements above and below clouds and in clear sky. Additional flight series are planned to continue study of the cloudy and clear sky energy budget in the Spring and Fall of 1996 over the DOE climate site in Oklahoma. 3 refs., 4 figs., 1 tab.« less

Marine ARM GPCI Investigation of Clouds Infrared Sea Surface Temperature Autonomous Radiometer (ISAR) Field Campaign Report

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

Reynolds, R. Michael; Long, Charles N.

Sea surface temperature (SST) is one of the most appropriate and important climate parameters: a widespread increase is an indicator of global warming and modifications of the geographical distribution of SST are an extremely sensitive indicator of climate change. There is high demand for accurate, reliable, high-spatial-and-temporal-resolution SST measurements for the parameterization of ocean-atmosphere heat, momentum, and gas (SST is therefore critical to understanding the processes controlling the global carbon dioxide budget) fluxes, for detailed diagnostic and process-orientated studies to better understand the behavior of the climate system, as model boundary conditions, for assimilation into climate models, and for themore » rigorous validation of climate model output. In order to achieve an overall net flux uncertainty < 10 W/m 2 (Bradley and Fairall, 2006), the sea surface (skin) temperature (SSST) must be measured to an error < 0.1 C and a precision of 0.05 C. Anyone experienced in shipboard meteorological measurements will recognize this is a tough specification. These demands require complete confidence in the content, interpretation, accuracy, reliability, and continuity of observational SST data—criteria that can only be fulfilled by the successful implementation of an ongoing data product validation strategy.« less

Unmanned Aerial Systems, Moored Balloons, and the U.S. Department of Energy ARM Facilities in Alaska

NASA Astrophysics Data System (ADS)

Ivey, Mark; Verlinde, Johannes

2014-05-01

The U.S. Department of Energy (DOE), through its scientific user facility, the Atmospheric Radiation Measurement (ARM) Climate Research Facility, provides scientific infrastructure and data to the international Arctic research community via its research sites located on the North Slope of Alaska. Facilities and infrastructure to support operations of unmanned aerial systems for science missions in the Arctic and North Slope of Alaska were established at Oliktok Point Alaska in 2013. Tethered instrumented balloons will be used in the near future to make measurements of clouds in the boundary layer including mixed-phase clouds. The DOE ARM Program has operated an atmospheric measurement facility in Barrow, Alaska, since 1998. Major upgrades to this facility, including scanning radars, were added in 2010. Arctic Observing Networks are essential to meet growing policy, social, commercial, and scientific needs. Calibrated, high-quality arctic geophysical datasets that span ten years or longer are especially important for climate studies, climate model initializations and validations, and for related climate policy activities. For example, atmospheric data and derived atmospheric forcing estimates are critical for sea-ice simulations. International requirements for well-coordinated, long-term, and sustained Arctic Observing Networks and easily-accessible data sets collected by those networks have been recognized by many high-level workshops and reports (Arctic Council Meetings and workshops, National Research Council reports, NSF workshops and others). The recent Sustaining Arctic Observation Network (SAON) initiative sponsored a series of workshops to "develop a set of recommendations on how to achieve long-term Arctic-wide observing activities that provide free, open, and timely access to high-quality data that will realize pan-Arctic and global value-added services and provide societal benefits." This poster will present information on opportunities for members of the arctic research community to make atmospheric measurements using unmanned aerial systems or tethered balloons.

Why do general circulation models overestimate the aerosol cloud lifetime effect? A case study comparing CAM5 and a CRM

DOE PAGES

Zhou, Cheng; Penner, Joyce E.

2017-01-02

Observation-based studies have shown that the aerosol cloud lifetime effect or the increase of cloud liquid water path (LWP) with increased aerosol loading may have been overestimated in climate models. Here, we simulate shallow warm clouds on 27 May 2011 at the southern Great Plains (SGP) measurement site established by the Department of Energy's (DOE) Atmospheric Radiation Measurement (ARM) program using a single-column version of a global climate model (Community Atmosphere Model or CAM) and a cloud resolving model (CRM). The LWP simulated by CAM increases substantially with aerosol loading while that in the CRM does not. The increase of LWP inmore » CAM is caused by a large decrease of the autoconversion rate when cloud droplet number increases. In the CRM, the autoconversion rate is also reduced, but this is offset or even outweighed by the increased evaporation of cloud droplets near the cloud top, resulting in an overall decrease in LWP. Lastly, our results suggest that climate models need to include the dependence of cloud top growth and the evaporation/condensation process on cloud droplet number concentrations.« less

Why do general circulation models overestimate the aerosol cloud lifetime effect? A case study comparing CAM5 and a CRM

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

Zhou, Cheng; Penner, Joyce E.

Observation-based studies have shown that the aerosol cloud lifetime effect or the increase of cloud liquid water path (LWP) with increased aerosol loading may have been overestimated in climate models. Here, we simulate shallow warm clouds on 27 May 2011 at the southern Great Plains (SGP) measurement site established by the Department of Energy's (DOE) Atmospheric Radiation Measurement (ARM) program using a single-column version of a global climate model (Community Atmosphere Model or CAM) and a cloud resolving model (CRM). The LWP simulated by CAM increases substantially with aerosol loading while that in the CRM does not. The increase of LWP inmore » CAM is caused by a large decrease of the autoconversion rate when cloud droplet number increases. In the CRM, the autoconversion rate is also reduced, but this is offset or even outweighed by the increased evaporation of cloud droplets near the cloud top, resulting in an overall decrease in LWP. Lastly, our results suggest that climate models need to include the dependence of cloud top growth and the evaporation/condensation process on cloud droplet number concentrations.« less

A versatile system for processing geostationary satellite data with run-time visualization capability

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

Landsfeld, M.; Gautier, C.; Figel, T.

1995-01-01

To better predict global climate change, scientists are developing climate models that require interdisciplinary and collaborative efforts in their building. The authors are currently involved in several such projects but will briefly discuss activities in support of two such complementary projects: the Atmospheric Radiation Measurement (ARM) program of the Department of Energy and Sequoia 2000, a joint venture of the University of California, the private sector, and government. The author`s contribution to the ARM program is to investigate the role of clouds on the top of the atmosphere and on surface radiance fields through the data analysis of surface andmore » satellite observations and complex modeling of the interaction of radiation with clouds. One of the first ARM research activities involves the computation of the broadband shortwave surface irradiance from satellite observations. Geostationary satellite images centered over the first ARM observation site are received hourly over the Internet network and processed in real time to compute hourly and daily composite shortwave irradiance fields. The images and the results are transferred via a high-speed network to the Sequoia 2000 storage facility in Berkeley, where they are archived. These satellite-derived results are compared with the surface observations to evaluate the accuracy of the satellite estimate and the spatial representation of the surface observations. In developing the software involved in calculating the surface shortwave irradiance, the authors have produced an environment whereby they can easily modify and monitor the data processing as required. Through the principles of modular programming, they have developed software that is easily modified as new algorithms for computation are developed or input data availability changes. In addition, the software was designed so that it could be run from an interactive, icon-driven, graphical interface, TCL-TK, developed by Sequoia 2000 participants.« less

Climate not to blame for African civil wars

PubMed Central

Buhaug, Halvard

2010-01-01

Vocal actors within policy and practice contend that environmental variability and shocks, such as drought and prolonged heat waves, drive civil wars in Africa. Recently, a widely publicized scientific article appears to substantiate this claim. This paper investigates the empirical foundation for the claimed relationship in detail. Using a host of different model specifications and alternative measures of drought, heat, and civil war, the paper concludes that climate variability is a poor predictor of armed conflict. Instead, African civil wars can be explained by generic structural and contextual conditions: prevalent ethno-political exclusion, poor national economy, and the collapse of the Cold War system. PMID:20823241

Atmospheric radiation measurement program facilities newsletter, September 2001.

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

Holdridge, D. J.

Our Changing Climate--Is our climate really changing? How do we measure climate change? How can we predict what Earth's climate will be like for generations to come? One focus of the Atmospheric Radiation Measurement (ARM) Program is to improve scientific climate models enough to achieve reliable regional prediction of future climate. According to the Environmental Protection Agency (EPA), the global mean surface temperature has increased by 0.5-1.0 F since the late 19th century. The 20th century's 10 warmest years all occurred in the last 15 years of the century, with 1998 being the warmest year of record. The global meanmore » surface temperature is measured by a network of temperature-sensing instruments distributed around the world, including ships, ocean buoys, and weather stations on land. The data from this network are retrieved and analyzed by various organizations, including the National Aeronautics and Space Administration, the National Oceanic and Atmospheric Administration, and the World Meteorological Organization. Worldwide temperature records date back to 1860. To reconstruct Earth's temperature history before 1860, scientists use limited temperature records, along with proxy indicators such as tree rings, pollen records, and analysis of air frozen in ancient ice. The solar energy received from the sun drives Earth's weather and climate. Some of this energy is reflected and filtered by the atmosphere, but most is absorbed by Earth's surface. The absorbed solar radiation warms the surface and is re-radiated as heat energy into the atmosphere. Some atmospheric gases, called greenhouse gases, trap some of the re-emitted heat, keeping the surface temperature regulated and suitable for sustaining life. Although the greenhouse effect is natural, some evidence indicates that human activities are producing increased levels of some greenhouse gases such as carbon dioxide, methane, and nitrous oxide. Scientists believe that the combustion of fossil fuels is responsible for the increased levels of carbon dioxide in the atmosphere. According to the EPA, the burning of fossil fuels for cars and trucks, the heating of homes and businesses, and the operation of power plants account for approximately 98% of U.S. carbon dioxide emissions. The increase of greenhouse gases will, theoretically, enhance the greenhouse effect by trapping more of the heat energy emitted by Earth's surface, thus increasing the surface temperatures on a global scale. Scientists expect that the global average surface temperature could rise 1-4.5 F in the next 50 years and as much as 10 F in the next century. Global warming could potentially have harmful effects on human health, water resources, forests, agriculture, wildlife, and coastal areas. A few degrees of warming might lead to more frequent and severe heat waves, worsened air pollution with adverse effects on human respiratory health, and wider spread of tropical disease such as malaria. The world's hydrologic cycle might be affected by an increase in evaporation and, thus, in precipitation. An increase in evaporation will increase atmospheric water vapor, a significant natural greenhouse gas. The increase in water vapor might further enhance the global warming caused by the greenhouse effect. This is known as a positive feedback. The increase in water vapor could also change the amount of clouds present in the atmosphere, which could reduce temperatures in a negative feedback. Many interrelated factors affect the global climate and are responsible for climate change. Predicting the outcome of the interactions among the many factors is not easy, but it must be addressed. The ARM Program is taking a lead in this effort by collecting vast amounts of data whose analysis will improve our forecasting models for both daily weather and long-term climate. For more information on the ARM Program, please visit our web site at www.arm.gov.« less

CARBON BALANCE OF THE CONTINUOUS PERMAFROST ZONE OF RUSSIA

EPA Science Inventory

An increase in the atmospheric concentration of CO2 is projected to cause climate warming. arming of the permafrost environment could change the balance between carbon accumulation and decomposition processes and substantially disrupt the equilibrium of the carbon cycle. arming m...

Using ARM Observations to Evaluate Climate Model Simulations of Land-Atmosphere Coupling on the U.S. Southern Great Plains

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

Phillips, Thomas J.; Klein, Stephen A.; Ma, Hsi -Yen

Several independent measurements of warm-season soil moisture and surface atmospheric variables recorded at the ARM Southern Great Plains (SGP) research facility are used to estimate the terrestrial component of land-atmosphere coupling (LAC) strength and its regional uncertainty. The observations reveal substantial variation in coupling strength, as estimated from three soil moisture measurements at a single site, as well as across six other sites having varied soil and land cover types. The observational estimates then serve as references for evaluating SGP terrestrial coupling strength in the Community Atmospheric Model coupled to the Community Land Model. These coupled model components are operatedmore » in both a free-running mode and in a controlled configuration, where the atmospheric and land states are reinitialized daily, so that they do not drift very far from observations. Although the controlled simulation deviates less from the observed surface climate than its free-running counterpart, the terrestrial LAC in both configurations is much stronger and displays less spatial variability than the SGP observational estimates. Preliminary investigation of vegetation leaf area index (LAI) substituted for soil moisture suggests that the overly strong coupling between model soil moisture and surface atmospheric variables is associated with too much evaporation from bare ground and too little from the vegetation cover. Lastly, these results imply that model surface characteristics such as LAI, as well as the physical parameterizations involved in the coupling of the land and atmospheric components, are likely to be important sources of the problematical LAC behaviors.« less

Using ARM Observations to Evaluate Climate Model Simulations of Land-Atmosphere Coupling on the U.S. Southern Great Plains

DOE PAGES

Phillips, Thomas J.; Klein, Stephen A.; Ma, Hsi -Yen; ...

2017-10-13

Several independent measurements of warm-season soil moisture and surface atmospheric variables recorded at the ARM Southern Great Plains (SGP) research facility are used to estimate the terrestrial component of land-atmosphere coupling (LAC) strength and its regional uncertainty. The observations reveal substantial variation in coupling strength, as estimated from three soil moisture measurements at a single site, as well as across six other sites having varied soil and land cover types. The observational estimates then serve as references for evaluating SGP terrestrial coupling strength in the Community Atmospheric Model coupled to the Community Land Model. These coupled model components are operatedmore » in both a free-running mode and in a controlled configuration, where the atmospheric and land states are reinitialized daily, so that they do not drift very far from observations. Although the controlled simulation deviates less from the observed surface climate than its free-running counterpart, the terrestrial LAC in both configurations is much stronger and displays less spatial variability than the SGP observational estimates. Preliminary investigation of vegetation leaf area index (LAI) substituted for soil moisture suggests that the overly strong coupling between model soil moisture and surface atmospheric variables is associated with too much evaporation from bare ground and too little from the vegetation cover. Lastly, these results imply that model surface characteristics such as LAI, as well as the physical parameterizations involved in the coupling of the land and atmospheric components, are likely to be important sources of the problematical LAC behaviors.« less

SciDAC's Earth System Grid Center for Enabling Technologies Semiannual Progress Report October 1, 2010 through March 31, 2011

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

Williams, Dean N.

2011-04-02

This report summarizes work carried out by the Earth System Grid Center for Enabling Technologies (ESG-CET) from October 1, 2010 through March 31, 2011. It discusses ESG-CET highlights for the reporting period, overall progress, period goals, and collaborations, and lists papers and presentations. To learn more about our project and to find previous reports, please visit the ESG-CET Web sites: http://esg-pcmdi.llnl.gov/ and/or https://wiki.ucar.edu/display/esgcet/Home. This report will be forwarded to managers in the Department of Energy (DOE) Scientific Discovery through Advanced Computing (SciDAC) program and the Office of Biological and Environmental Research (OBER), as well as national and international collaborators andmore » stakeholders (e.g., those involved in the Coupled Model Intercomparison Project, phase 5 (CMIP5) for the Intergovernmental Panel on Climate Change (IPCC) 5th Assessment Report (AR5); the Community Earth System Model (CESM); the Climate Science Computational End Station (CCES); SciDAC II: A Scalable and Extensible Earth System Model for Climate Change Science; the North American Regional Climate Change Assessment Program (NARCCAP); the Atmospheric Radiation Measurement (ARM) program; the National Aeronautics and Space Administration (NASA), the National Oceanic and Atmospheric Administration (NOAA)), and also to researchers working on a variety of other climate model and observation evaluation activities. The ESG-CET executive committee consists of Dean N. Williams, Lawrence Livermore National Laboratory (LLNL); Ian Foster, Argonne National Laboratory (ANL); and Don Middleton, National Center for Atmospheric Research (NCAR). The ESG-CET team is a group of researchers and scientists with diverse domain knowledge, whose home institutions include eight laboratories and two universities: ANL, Los Alamos National Laboratory (LANL), Lawrence Berkeley National Laboratory (LBNL), LLNL, NASA/Jet Propulsion Laboratory (JPL), NCAR, Oak Ridge National Laboratory (ORNL), Pacific Marine Environmental Laboratory (PMEL)/NOAA, Rensselaer Polytechnic Institute (RPI), and University of Southern California, Information Sciences Institute (USC/ISI). All ESG-CET work is accomplished under DOE open-source guidelines and in close collaboration with the project's stakeholders, domain researchers, and scientists. Through the ESG project, the ESG-CET team has developed and delivered a production environment for climate data from multiple climate model sources (e.g., CMIP (IPCC), CESM, ocean model data (e.g., Parallel Ocean Program), observation data (e.g., Atmospheric Infrared Sounder, Microwave Limb Sounder), and analysis and visualization tools) that serves a worldwide climate research community. Data holdings are distributed across multiple sites including LANL, LBNL, LLNL, NCAR, and ORNL as well as unfunded partners sites such as the Australian National University (ANU) National Computational Infrastructure (NCI), the British Atmospheric Data Center (BADC), the Geophysical Fluid Dynamics Laboratory/NOAA, the Max Planck Institute for Meteorology (MPI-M), the German Climate Computing Centre (DKRZ), and NASA/JPL. As we transition from development activities to production and operations, the ESG-CET team is tasked with making data available to all users who want to understand it, process it, extract value from it, visualize it, and/or communicate it to others. This ongoing effort is extremely large and complex, but it will be incredibly valuable for building 'science gateways' to critical climate resources (such as CESM, CMIP5, ARM, NARCCAP, Atmospheric Infrared Sounder (AIRS), etc.) for processing the next IPCC assessment report. Continued ESG progress will result in a production-scale system that will empower scientists to attempt new and exciting data exchanges, which could ultimately lead to breakthrough climate science discoveries.« less

Representing winter wheat in the Community Land Model (version 4.5)

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

Lu, Yaqiong; Williams, Ian N.; Bagley, Justin E.

Winter wheat is a staple crop for global food security, and is the dominant vegetation cover for a significant fraction of Earth's croplands. As such, it plays an important role in carbon cycling and land–atmosphere interactions in these key regions. Accurate simulation of winter wheat growth is not only crucial for future yield prediction under a changing climate, but also for accurately predicting the energy and water cycles for winter wheat dominated regions. We modified the winter wheat model in the Community Land Model (CLM) to better simulate winter wheat leaf area index, latent heat flux, net ecosystem exchange ofmore » CO 2, and grain yield. These included schemes to represent vernalization as well as frost tolerance and damage. We calibrated three key parameters (minimum planting temperature, maximum crop growth days, and initial value of leaf carbon allocation coefficient) and modified the grain carbon allocation algorithm for simulations at the US Southern Great Plains ARM site (US-ARM), and validated the model performance at eight additional sites across North America. We found that the new winter wheat model improved the prediction of monthly variation in leaf area index, reduced latent heat flux, and net ecosystem exchange root mean square error (RMSE) by 41 and 35 % during the spring growing season. The model accurately simulated the interannual variation in yield at the US-ARM site, but underestimated yield at sites and in regions (northwestern and southeastern US) with historically greater yields by 35 %.« less

Representing winter wheat in the Community Land Model (version 4.5)

NASA Astrophysics Data System (ADS)

Lu, Yaqiong; Williams, Ian N.; Bagley, Justin E.; Torn, Margaret S.; Kueppers, Lara M.

2017-05-01

Winter wheat is a staple crop for global food security, and is the dominant vegetation cover for a significant fraction of Earth's croplands. As such, it plays an important role in carbon cycling and land-atmosphere interactions in these key regions. Accurate simulation of winter wheat growth is not only crucial for future yield prediction under a changing climate, but also for accurately predicting the energy and water cycles for winter wheat dominated regions. We modified the winter wheat model in the Community Land Model (CLM) to better simulate winter wheat leaf area index, latent heat flux, net ecosystem exchange of CO2, and grain yield. These included schemes to represent vernalization as well as frost tolerance and damage. We calibrated three key parameters (minimum planting temperature, maximum crop growth days, and initial value of leaf carbon allocation coefficient) and modified the grain carbon allocation algorithm for simulations at the US Southern Great Plains ARM site (US-ARM), and validated the model performance at eight additional sites across North America. We found that the new winter wheat model improved the prediction of monthly variation in leaf area index, reduced latent heat flux, and net ecosystem exchange root mean square error (RMSE) by 41 and 35 % during the spring growing season. The model accurately simulated the interannual variation in yield at the US-ARM site, but underestimated yield at sites and in regions (northwestern and southeastern US) with historically greater yields by 35 %.

Representing winter wheat in the Community Land Model (version 4.5)

DOE PAGES

Lu, Yaqiong; Williams, Ian N.; Bagley, Justin E.; ...

2017-05-05

Winter wheat is a staple crop for global food security, and is the dominant vegetation cover for a significant fraction of Earth's croplands. As such, it plays an important role in carbon cycling and land–atmosphere interactions in these key regions. Accurate simulation of winter wheat growth is not only crucial for future yield prediction under a changing climate, but also for accurately predicting the energy and water cycles for winter wheat dominated regions. We modified the winter wheat model in the Community Land Model (CLM) to better simulate winter wheat leaf area index, latent heat flux, net ecosystem exchange ofmore » CO 2, and grain yield. These included schemes to represent vernalization as well as frost tolerance and damage. We calibrated three key parameters (minimum planting temperature, maximum crop growth days, and initial value of leaf carbon allocation coefficient) and modified the grain carbon allocation algorithm for simulations at the US Southern Great Plains ARM site (US-ARM), and validated the model performance at eight additional sites across North America. We found that the new winter wheat model improved the prediction of monthly variation in leaf area index, reduced latent heat flux, and net ecosystem exchange root mean square error (RMSE) by 41 and 35 % during the spring growing season. The model accurately simulated the interannual variation in yield at the US-ARM site, but underestimated yield at sites and in regions (northwestern and southeastern US) with historically greater yields by 35 %.« less

Evaluation of Cirrus Cloud Simulations using ARM Data-Development of Case Study Data Set

NASA Technical Reports Server (NTRS)

Starr, David OC.; Demoz, Belay; Wang, Yansen; Lin, Ruei-Fong; Lare, Andrew; Mace, Jay; Poellot, Michael; Sassen, Kenneth; Brown, Philip

2002-01-01

Cloud-resolving models (CRMs) are being increasingly used to develop parametric treatments of clouds and related processes for use in global climate models (GCMs). CRMs represent the integrated knowledge of the physical processes acting to determine cloud system lifecycle and are well matched to typical observational data in terms of physical parameters/measurables and scale-resolved physical processes. Thus, they are suitable for direct comparison to field observations for model validation and improvement. The goal of this project is to improve state-of-the-art CRMs used for studies of cirrus clouds and to establish a relative calibration with GCMs through comparisons among CRMs, single column model (SCM) versions of the GCMs, and observations. The objective is to compare and evaluate a variety of CRMs and SCMs, under the auspices of the GEWEX Cloud Systems Study (GCSS) Working Group on Cirrus Cloud Systems (WG2), using ARM data acquired at the Southern Great Plains (SGP) site. This poster will report on progress in developing a suitable WG2 case study data set based on the September 26, 1996 ARM IOP case - the Hurricane Nora outflow case. Progress is assessing cloud and other environmental conditions will be described. Results of preliminary simulations using a regional cloud system model (MM5) and a CRM will be discussed. Focal science questions for the model comparison are strongly based on results of the idealized GCSS WG2 cirrus cloud model comparison projects (Idealized Cirrus Cloud Model Comparison Project and Cirrus Parcel Model Comparison Project), which will also be briefly summarized.

A Unified Approach for Reporting ARM Measurement Uncertainties Technical Report

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

Campos, E; Sisterson, DL

The Atmospheric Radiation Measurement (ARM) Climate Research Facility is observationally based, and quantifying the uncertainty of its measurements is critically important. With over 300 widely differing instruments providing over 2,500 datastreams, concise expression of measurement uncertainty is quite challenging. The ARM Facility currently provides data and supporting metadata (information about the data or data quality) to its users through a number of sources. Because the continued success of the ARM Facility depends on the known quality of its measurements, the Facility relies on instrument mentors and the ARM Data Quality Office (DQO) to ensure, assess, and report measurement quality. Therefore,more » an easily-accessible, well-articulated estimate of ARM measurement uncertainty is needed.« less

ARM-ACME V: ARM Airborne Carbon Measurements V on the North Slope of Alaska Field Campaign Report

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

Biraud, Sebastien C

2016-05-01

Atmospheric temperatures are warming faster in the Arctic than predicted by climate models. The impact of this warming on permafrost degradation is not well understood, but it is projected to increase carbon decomposition and greenhouse gas production (CO2 and/or CH4) by arctic ecosystems. Airborne observations of atmospheric trace gases, aerosols and cloud properties in North Slopes of Alaska (NSA) are improving our understanding of global climate, with the goal of reducing the uncertainty in global and regional climate simulations and projections. From June 1 through September 15, 2015, AAF deployed the G1 research aircraft and flew over the North Slopemore » of Alaska (38 flights, 140 science flight hours), with occasional vertical profiling over Prudhoe Bay, Oliktok point, Barrow, Atqasuk, Ivotuk, and Toolik Lake. The aircraft payload included Picarro and Los Gatos Research (LGR) analyzers for continuous measurements of CO2, CH4, H2O, and CO and N2O mixing ratios, and a 12-flask sampler for analysis of carbon cycle gases (CO2, CO, CH4, N2O, 13CO2, and trace hydrocarbon species). The aircraft payload also include measurements of aerosol properties (number size distribution, total number concentration, absorption, and scattering), cloud properties (droplet and ice size information), atmospheric thermodynamic state, and solar/infrared radiation.« less

Climate risks workshop

NASA Image and Video Library

2012-10-16

Participants in an Oct. 16-18 workshop at John C. Stennis Space Center focused on identifying current and future climate risks and developing strategies to address them. NASA Headquarters sponsored the Resilience and Adaptation to Climate Risks Workshop to understand climate change risks and adaptation strategies. The workshop was part of an effort that joins the science and operations arms of the agency in a coordinated response to climate change. NASA Headquarters is holding workshops on the subject at all NASA centers.

Contributions of the ARM Program to Radiative Transfer Modeling for Climate and Weather Applications

NASA Technical Reports Server (NTRS)

Mlawer, Eli J.; Iacono, Michael J.; Pincus, Robert; Barker, Howard W.; Oreopoulos, Lazaros; Mitchell, David L.

2016-01-01

Accurate climate and weather simulations must account for all relevant physical processes and their complex interactions. Each of these atmospheric, ocean, and land processes must be considered on an appropriate spatial and temporal scale, which leads these simulations to require a substantial computational burden. One especially critical physical process is the flow of solar and thermal radiant energy through the atmosphere, which controls planetary heating and cooling and drives the large-scale dynamics that moves energy from the tropics toward the poles. Radiation calculations are therefore essential for climate and weather simulations, but are themselves quite complex even without considering the effects of variable and inhomogeneous clouds. Clear-sky radiative transfer calculations have to account for thousands of absorption lines due to water vapor, carbon dioxide, and other gases, which are irregularly distributed across the spectrum and have shapes dependent on pressure and temperature. The line-by-line (LBL) codes that treat these details have a far greater computational cost than can be afforded by global models. Therefore, the crucial requirement for accurate radiation calculations in climate and weather prediction models must be satisfied by fast solar and thermal radiation parameterizations with a high level of accuracy that has been demonstrated through extensive comparisons with LBL codes. See attachment for continuation.

ARM Radiosondes for National Polar-Orbiting Operational Environmental Satellite System Preparatory Project Validation Field Campaign Report

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

Borg, Lori; Tobin, David; Reale, Anthony

This IOP has been a coordinated effort involving the U.S. Department of Energy (DOE) Atmospheric Radiation (ARM) Climate Research Facility, the University of Wisconsin (UW)-Madison, and the JPSS project to validate SNPP NOAA Unique Combined Atmospheric Processing System (NUCAPS) temperature and moisture sounding products from the Cross-track Infrared Sounder (CrIS) and the Advanced Technology Microwave Sounder (ATMS). In this arrangement, funding for radiosondes was provided by the JPSS project to ARM. These radiosondes were launched coincident with the SNPP satellite overpasses (OP) at four of the ARM field sites beginning in July 2012 and running through September 2017. Combined withmore » other ARM data, an assessment of the radiosonde data quality was performed and post-processing corrections applied producing an ARM site Best Estimate (BE) product. The SNPP targeted radiosondes were integrated into the NOAA Products Validation System (NPROVS+) system, which collocated the radiosondes with satellite products (NOAA, National Aeronautics and Space Administration [NASA], European Organisation for the Exploitation of Meteorological Satellites [EUMETSAT], Geostationary Operational Environmental Satellite [GOES], Constellation Observing System for Meteorology, Ionosphere, and Climate [COSMIC]) and Numerical Weather Prediction (NWP forecasts for use in product assessment and algorithm development. This work was a fundamental, integral, and cost-effective part of the SNPP validation effort and provided critical accuracy assessments of the SNPP temperature and water vapor soundings.« less

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

Voyles, Jimmy

Individual datastreams from instrumentation at the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility fixed and mobile research observatories (sites) are collected and routed to the ARM Data Center (ADC). The Data Management Facility (DMF), a component of the ADC, executes datastream processing in near-real time. Processed data are then delivered approximately daily to the ARM Data Archive, also a component of the ADC, where they are made freely available to the research community. For each instrument, ARM calculates the ratio of the actual number of processed data records received daily at the ARM Data Archivemore » to the expected number of data records. DOE requires national user facilities to report time-based operating data.« less

Cloud-Scale Numerical Modeling of the Arctic Boundary Layer

NASA Technical Reports Server (NTRS)

Krueger, Steven K.

1998-01-01

The interactions between sea ice, open ocean, atmospheric radiation, and clouds over the Arctic Ocean exert a strong influence on global climate. Uncertainties in the formulation of interactive air-sea-ice processes in global climate models (GCMs) result in large differences between the Arctic, and global, climates simulated by different models. Arctic stratus clouds are not well-simulated by GCMs, yet exert a strong influence on the surface energy budget of the Arctic. Leads (channels of open water in sea ice) have significant impacts on the large-scale budgets during the Arctic winter, when they contribute about 50 percent of the surface fluxes over the Arctic Ocean, but cover only 1 to 2 percent of its area. Convective plumes generated by wide leads may penetrate the surface inversion and produce condensate that spreads up to 250 km downwind of the lead, and may significantly affect the longwave radiative fluxes at the surface and thereby the sea ice thickness. The effects of leads and boundary layer clouds must be accurately represented in climate models to allow possible feedbacks between them and the sea ice thickness. The FIRE III Arctic boundary layer clouds field program, in conjunction with the SHEBA ice camp and the ARM North Slope of Alaska and Adjacent Arctic Ocean site, will offer an unprecedented opportunity to greatly improve our ability to parameterize the important effects of leads and boundary layer clouds in GCMs.

Satellite Calibration and Verification of Remotely Sensed Cloud and Radiation Properties Using ARM UAV Data

NASA Technical Reports Server (NTRS)

Minnis, Patrick; Charlock, Thomas P.

1998-01-01

The work proposed under this agreement was designed to validate and improve remote sensing of cloud and radiation properties in the atmosphere for climate studies with special emphasis on the use of satellites for monitoring these parameters to further the goals of the Atmospheric Radiation Measurement (ARM) Program.

ARM Data File Standards Version: 1.0

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

Kehoe, Kenneth; Beus, Sherman; Cialella, Alice

2014-04-01

The Atmospheric Radiation Measurement (ARM) Climate Research Facility performs routine in situ and remote-sensing observations to provide a detailed and accurate description of the Earth atmosphere in diverse climate regimes. The result is a diverse data sets containing observational and derived data, currently accumulating at a rate of 30 TB of data and 150,000 different files per month (http://www.archive.arm.gov/stats/storage2.html). Continuing the current processing while scaling this to even larger sizes is extremely important to the ARM Facility and requires consistent metadata and data standards. The standards described in this document will enable development of automated analysis and discovery tools formore » the ever-growing volumes of data. It also will enable consistent analysis of the multiyear data, allow for development of automated monitoring and data health status tools, and facilitate development of future capabilities for delivering data on demand that can be tailored explicitly to user needs. This analysis ability will only be possible if the data follows a minimum set of standards. This document proposes a hierarchy that includes required and recommended standards.« less

ARM Airborne Carbon Measurements (ARM-ACME) and ARM-ACME 2.5 Final Campaign Reports

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

Biraud, S. C.; Tom, M. S.; Sweeney, C.

2016-01-01

We report on a 5-year multi-institution and multi-agency airborne study of atmospheric composition and carbon cycling at the Atmospheric Radiation Measurement (ARM) Climate Research Facility’s Southern Great Plains (SGP) site, with scientific objectives that are central to the carbon-cycle and radiative-forcing goals of the U.S. Global Change Research Program and the North American Carbon Program (NACP). The goal of these measurements is to improve understanding of 1) the carbon exchange of the Atmospheric Radiation Measurement (ARM) SGP region; 2) how CO 2 and associated water and energy fluxes influence radiative-forcing, convective processes, and CO 2 concentrations over the ARM SGPmore » region, and 3) how greenhouse gases are transported on continental scales.« less

Climatology analysis of cirrus cloud in ARM site: South Great Plain

NASA Astrophysics Data System (ADS)

Olayinka, K.

2017-12-01

Cirrus cloud play an important role in the atmospheric energy balance and hence in the earth's climate system. The properties of optically thin clouds can be determined from measurements of transmission of the direct solar beam. The accuracy of cloud optical properties determined in this way is compromised by contamination of the direct transmission by light that is scattered into the sensors field of view. With the forward scattering correction method developed by Min et al., (2004), the accuracy of thin cloud retrievals from MFRSR has been improved. Our result shows over 30% of cirrus cloud present in the atmosphere are within optical depth between (1-2). In this study, we do statistics studies on cirrus clouds properties based on multi-years cirrus cloud measurements from MFRSR at ARM site from the South Great Plain (SGP) site due to its relatively easy accessibility, wide variability of climate cloud types and surface flux properties, large seasonal variation in temperature and specific humidity. Through the statistic studies, temporal and spatial variations of cirrus clouds are investigated. Since the presence of cirrus cloud increases the effect of greenhouse gases, we will retrieve the aerosol optical depth in all the cirrus cloud regions using a radiative transfer model for atmospheric correction. Calculate thin clouds optical depth (COD), and aerosol optical depth (AOD) using a radiative transfer model algorithm, e.g.: MODTRAN (MODerate resolution atmospheric TRANsmission)

Application of Seasonal CRM Integrations to Develop Statistics and Improved GCM Parameterization of Subgrid Cloud-Radiation Interactions

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

Xiaoqing Wu; Xin-Zhong Liang; Sunwook Park

2007-01-23

The works supported by this ARM project lay the solid foundation for improving the parameterization of subgrid cloud-radiation interactions in the NCAR CCSM and the climate simulations. We have made a significant use of CRM simulations and concurrent ARM observations to produce long-term, consistent cloud and radiative property datasets at the cloud scale (Wu et al. 2006, 2007). With these datasets, we have investigated the mesoscale enhancement of cloud systems on surface heat fluxes (Wu and Guimond 2006), quantified the effects of cloud horizontal inhomogeneity and vertical overlap on the domain-averaged radiative fluxes (Wu and Liang 2005), and subsequently validatedmore » and improved the physically-based mosaic treatment of subgrid cloud-radiation interactions (Liang and Wu 2005). We have implemented the mosaic treatment into the CCM3. The 5-year (1979-1983) AMIP-type simulation showed significant impacts of subgrid cloud-radiation interaction on the climate simulations (Wu and Liang 2005). We have actively participated in CRM intercomparisons that foster the identification and physical understanding of common errors in cloud-scale modeling (Xie et al. 2005; Xu et al. 2005, Grabowski et al. 2005).« less

A versatile system for processing geostationary satellite data with run-time visualization capability

NASA Technical Reports Server (NTRS)

Landsfeld, M.; Gautier, C.; Figel, T.

1995-01-01

To better predict global climate change, scientists are developing climate models that require interdisciplinary and collaborative efforts in their building. We are currently involved in several such projects but will briefly discuss activities in support of two such complementary projects: the Atmospheric Radiation Measurement (ARM) program of the Department of Energy and Sequoia 2000, a joint venture of the University of California, the private sector, and government agencies. Our contribution to the ARM program is to investigate the role of clouds on the top of the atmosphere and on surface radiance fields through the data analysis of surface and satellite observations and complex modeling of the interaction of radiation with clouds. One of our first ARM research activities involves the computation of the broadband shortwave surface irradiance from satellite observations. Geostationary satellite images centered over the first ARM observation site are received hourly over the Internet network and processed in real time to compute hourly and daily composite shortwave irradiance fields. The images and the results are transferred via a high-speed network to the Sequoia 2000 storage facility in Berkeley, where they are archived These satellite-derived results are compared with the surface observations to evaluate the accuracy of the satellite estimate and the spatial representation of the surface observations. In developing the software involved in calculating the surface shortwave irradiance, we have produced an environment whereby we can easily modify and monitor the data processing as required. Through the principles of modular programming, we have developed software that is easily modified as new algorithms for computation are developed or input data availability changes. In addition, the software was designed so that it could be run from an interactive, icon-driven, graphical interface, TCL-TK, developed by Sequoia 2000 participants. In this way, the data flow can be interactively assessed and altered as needed. In this environment, the intermediate data processing 'images' can be viewed, enabling the investigator to easily monitor the various data processing steps as they progress. Additionally, this environment allows the rapid testing of new processing modules and allows their effects to be visually compared with previous results.

ARM Unmanned Aerial Systems Implementation Plan

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

Schmid, Beat; Ivey, Mark

Recent advances in Unmanned Aerial Systems (UAS) coupled with changes in the regulatory environment for operations of UAS in the National Airspace increase the potential value of UAS to the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility. UAS include unmanned aerial vehicles (UAV) and tethered balloon systems (TBS). The roles UAVs and TBSs could play within the ARM Facility, particularly science questions they could help address, have been discussed in several workshops, reports, and vision documents, including: This document describes the implementation of a robust and vigorous program for use of UAV and TBS formore » the science missions ARM supports.« less

JPRS Report, Arms Control

DTIC Science & Technology

1989-10-20

to them. This vast land has only very few people and its climate is mild. With a total area of over 100,000 square km, it is larger than Zhejiang...Mandarin 1030 GMT 17 Sep 89 ["Roster of Heroes and Model Workers"—on Sun Jingliang, chief designer of Long March Carrier Rocket IV, member of the...the building of new housing for U.S. forces and the refurbishing of present ones. Tatsu Arima , director general of the Foreign Ministry’s North

Broadband Outdoor Radiometer Calibration Process for the Atmospheric Radiation Measurement Program

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

Dooraghi, Michael

2015-09-01

The Atmospheric Radiation Measurement program (ARM) maintains a fleet of monitoring stations to aid in the improved scientific understanding of the basic physics related to radiative feedback processes in the atmosphere, particularly the interactions among clouds and aerosols. ARM obtains continuous measurements and conducts field campaigns to provide data products that aid in the improvement and further development of climate models. All of the measurement campaigns include a suite of solar measurements. The Solar Radiation Research Laboratory at the National Renewable Energy Laboratory supports ARM's full suite of stations in a number of ways, including troubleshooting issues that arise asmore » part of the data-quality reviews; managing engineering changes to the standard setup; and providing calibration services and assistance to the full fleet of solar-related instruments, including pyranometers, pyrgeometers, pyrheliometers, as well as the temperature/relative humidity probes, multimeters, and data acquisition systems that are used in the calibrations performed at the Southern Great Plains Radiometer Calibration Facility. This paper discusses all aspects related to the support provided to the calibration of the instruments in the solar monitoring fleet.« less

Central Sensitization and Perceived Indoor Climate among Workers with Chronic Upper-Limb Pain: Cross-Sectional Study

PubMed Central

Jakobsen, Markus D.; Jay, Kenneth; Persson, Roger; Andersen, Lars L.

2015-01-01

Monitoring of indoor climate is an essential part of occupational health and safety. While questionnaires are commonly used for surveillance, not all workers may perceive an identical indoor climate similarly. The aim of this study was to evaluate perceived indoor climate among workers with chronic pain compared with pain-free colleagues and to determine the influence of central sensitization on this perception. Eighty-two male slaughterhouse workers, 49 with upper-limb chronic pain and 33 pain-free controls, replied to a questionnaire with 13 items of indoor climate complaints. Pressure pain threshold (PPT) was measured in muscles of the arm, shoulder, and lower leg. Cross-sectional associations were determined using general linear models controlled for age, smoking, and job position. The number of indoor climate complaints was twice as high among workers with chronic pain compared with pain-free controls (1.8 [95% CI: 1.3–2.3] versus 0.9 [0.4–1.5], resp.). PPT of the nonpainful leg muscle was negatively associated with the number of complaints. Workers with chronic pain reported more indoor climate complaints than pain-free controls despite similar actual indoor climate. Previous studies that did not account for musculoskeletal pain in questionnaire assessment of indoor climate may be biased. Central sensitization likely explains the present findings. PMID:26425368

Deformation Rates From Climate Cycles in Marine Synorogenic Turbidites, Jaca Basin, Spanish Pyrenees

NASA Astrophysics Data System (ADS)

Anastasio, D. J.; Kodama, K. P.; Pares, J. M.; Hinnov, L. A.

2007-12-01

Synsedimentary structures provide a link between depositional and deformational processes in orogenic belts. Marine growth strata offer great promise in determining precise long-term deformation rates such as uplift, shortening, fault-slip, and folding rates. Magnetostratigraphy and cyclostratigraphy of the Eocene Arguis Fm., a delta slope deposit and the overlying delta plain Belsue-Atares Fm. monitors the varying pace of deformation at Pico del Aguila, a transverse decollement fold in the south Pyrenean foothills. Anhysteretic remanent magnetization (ARM) data show hierarchical cyclicity at all predicted Milankovitch frequencies. ARM is a proxy for fine-grained detrital magnetite concentration. The age distorting effects of pre-lithification compaction on bed thickness and on the rock and paleomagnetic data series were removed using empirical calibration of anisotropy of anhysteretic remanence magnetization to volume loss from laboratory compaction experiments. The decompacted ARM depth domain was converted to time using an improved magnetostratigraphy within the growth section. Tuning filtered ARM data series to the precession index according to the LA2004 orbital model refined the magnetostratigraphic time scale. The precession-tuned growth strata mapped with precision GPS record variable folding rates at 100skyr timescales for 7 Myr and55° of limb tilt. Folding rates accelerate twice to ~30°/Myr and are punctuated by more gradual decelerations to 0-3°/Myr. Submarine folding rates at Pico del Aguila are attributed to episodic thrusting in the fold core along a roof ramp fault and along the basal decollement. Formation-scale deposition in the Paleogene wedge-top basin responded to tectonic forcing, however, clastic facies patterns in the prodeltaic and slope environments reflect regional uplift controlling sediment supply, sea level variations controlling delta front position and climate forcing (e.g. monsoon strength and frequency, pedogenesis) of runoff variability and ecology in intermountain watersheds. Lithologic parameters sensitive to sea level, such as bed thickness and grain size variations in the turbidite section record strong obliquity and eccentricity modulation, whereas, the ARM derived magnetite concentrations record terrestrial watershed sensitive processes such as aridity and windiness operating at precessional time scales.

Sensitivity of the East African rift lakes to climate variability

NASA Astrophysics Data System (ADS)

Olaka, L.; Trauth, M. H.

2009-04-01

Lakes in the East African Rift have provided excellent proxies to reconstruct past climate changes in the low latitudes. The lakes occupy volcano-tectonic depressions with highly variable climate and hydrological setting, that present a good opportunity to study the climatic and hydrogeological influences on the lake water budget. Previous studies have used lake floor sediments to establish the sensitivity of the East African rift lakes. This study focuses on geomorphology and climate to offer additional or alternative record of lake history that are key to quantifying sensitivity of these lakes as archives to external and internal climatic forcings. By using the published Holocene lake areas and levels, we analyze twelve lakes on the eastern arm of the East African rift; Ziway, Awassa, Turkana, Suguta, Baringo, Nakuru, Elmenteita, Naivasha, Natron, Manyara and compare with Lake Victoria, that occupies the plateau between the east and the western arms of the rift. Using the SRTM data, Hypsometric (area-altitude) analysis has been used to compare the lake basins between latitude 80 North and 30 South. The mean elevation for the lakes, is between 524 and 2262 meters above sea level, the lakes' hypsometric integrals (HI), a measure of landmass volume above the reference plane, vary from 0.31 to 0.76. The aridity index (Ai), defined as Precipitation/ Evapotranspiration, quantifies the water available to a lake, it encompasses land cover and climatic effects. It is lowest (arid) in the basin between the Ethiopian rift and the Kenyan rift and at the southern termination of the Kenyan Rift in the catchments of lake Turkana, Suguta, Baringo and Manyara with values of 0.55, 0.43, 0.43 and 0.5 respectively. And it is highest (wet) in the catchments of, Ziway, Awassa, Nakuru and Naivasha as 1.33,1.03 and 1.2 respectively, which occupy the highest points of the rift. Lake Victoria has an index of 1.42 the highest of these lakes and receives a high precipitation. We use a simple model written on a Matlab code to illustrate the lake volume and area response to climate of surficialy closed, graben shaped and panshaped lake basins. From preliminary results, lake basins that are sensitive to climate variability have a high HI and high aridity index, which will be presented in this conference

CAUSES: On the Role of Surface Energy Budget Errors to the Warm Surface Air Temperature Error Over the Central United States

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

Ma, H. -Y.; Klein, S. A.; Xie, S.

Many weather forecasting and climate models simulate a warm surface air temperature (T2m) bias over mid-latitude continents during the summertime, especially over the Great Plains. We present here one of a series of papers from a multi-model intercomparison project (CAUSES: Cloud Above the United States and Errors at the Surface), which aims to evaluate the role of cloud, radiation, and precipitation biases in contributing to T2m bias using a short-term hindcast approach with observations mainly from the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site during the period of April to August 2011. The present study examines the contributionmore » of surface energy budget errors to the bias. All participating models simulate higher net shortwave and longwave radiative fluxes at the surface but there is no consistency on signs of biases in latent and sensible heat fluxes over the Central U.S. and ARM SGP. Nevertheless, biases in net shortwave and downward longwave fluxes, as well as surface evaporative fraction (EF) are the main contributors to T2m bias. Radiation biases are largely affected by cloud simulations, while EF is affected by soil moisture modulated by seasonal accumulated precipitation and evaporation. An approximate equation is derived to further quantify the magnitudes of radiation and EF contributions to T2m bias. Our analysis suggests that radiation errors are always an important source of T2m error for long-term climate runs with EF errors either of equal or lesser importance. However, for the short-term hindcasts, EF errors are more important provided a model has a substantial EF bias.« less

Data always getting bigger -- A scalable DOI architecture for big and expanding scientific data

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

Prakash, Giri; Shrestha, Biva; Younkin, Katarina

The Atmospheric Radiation Measurement (ARM) Data Archive established a data citation strategy based on Digital Object Identifiers (DOIs) for the ARM datasets in order to facilitate citing continuous and diverse ARM datasets in articles and other papers. This strategy eases the tracking of data provided as supplements to articles and papers. Additionally, it allows future data users and the ARM Climate Research Facility to easily locate the exact data used in various articles. Traditionally, DOIs are assigned to individual digital objects (a report or a data table), but for ARM datasets, these DOIs are assigned to an ARM data product.more » This eliminates the need for creating DOIs for numerous components of the ARM data product, in turn making it easier for users to manage and cite the ARM data with fewer DOIs. In addition, the ARM data infrastructure team, with input from scientific users, developed a citation format and an online data citation generation tool for continuous data streams. As a result, this citation format includes DOIs along with additional details such as spatial and temporal information.« less

Data always getting bigger -- A scalable DOI architecture for big and expanding scientific data

DOE PAGES

Prakash, Giri; Shrestha, Biva; Younkin, Katarina; ...

2016-08-31

The Atmospheric Radiation Measurement (ARM) Data Archive established a data citation strategy based on Digital Object Identifiers (DOIs) for the ARM datasets in order to facilitate citing continuous and diverse ARM datasets in articles and other papers. This strategy eases the tracking of data provided as supplements to articles and papers. Additionally, it allows future data users and the ARM Climate Research Facility to easily locate the exact data used in various articles. Traditionally, DOIs are assigned to individual digital objects (a report or a data table), but for ARM datasets, these DOIs are assigned to an ARM data product.more » This eliminates the need for creating DOIs for numerous components of the ARM data product, in turn making it easier for users to manage and cite the ARM data with fewer DOIs. In addition, the ARM data infrastructure team, with input from scientific users, developed a citation format and an online data citation generation tool for continuous data streams. As a result, this citation format includes DOIs along with additional details such as spatial and temporal information.« less

Data Management Facility Operations Plan

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

Keck, Nicole N

2014-06-30

The Data Management Facility (DMF) is the data center that houses several critical Atmospheric Radiation Measurement (ARM) Climate Research Facility services, including first-level data processing for the ARM Mobile Facilities (AMFs), Eastern North Atlantic (ENA), North Slope of Alaska (NSA), Southern Great Plains (SGP), and Tropical Western Pacific (TWP) sites, as well as Value-Added Product (VAP) processing, development systems, and other network services.

ARM Cloud-Aerosol-Precipitation Experiment (ACAPEX) Field Campaign Report

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

Leung, L Ruby

The U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility’s ARM Cloud-Aerosol-Precipitation Experiment (ACAPEX) field campaign contributes to CalWater 2015, a multi-agency field campaign that aims to improve understanding of atmospheric rivers and aerosol sources and transport that influence cloud and precipitation processes. The ultimate goal is to reduce uncertainties in weather predictions and climate projections of droughts and floods in California. With the DOE G-1 aircraft and ARM Mobile Facility 2 (AMF2) well equipped for making aerosol and cloud measurements, ACAPEX focuses specifically on understanding how aerosols from local pollution and long-range transport affect the amountmore » and phase of precipitation associated with atmospheric rivers. ACAPEX took place between January 12, 2015 and March 8, 2015 as part of CalWater 2015, which included four aircraft (DOE G-1, National Oceanic and Atmospheric Administration [NOAA] G-IV and P-3, and National Aeronautics and Space Administration [NASA] ER-2), the NOAA research ship Ron Brown, carrying onboard the AMF2, National Science Foundation (NSF)-sponsored aerosol and precipitation measurements at Bodega Bay, and the California Department of Water Resources extreme precipitation network.« less

Validation of a radiosonde-based cloud layer detection method against a ground-based remote sensing method at multiple ARM sites

NASA Astrophysics Data System (ADS)

Zhang, Jinqiang; Li, Zhanqing; Chen, Hongbin; Cribb, Maureen

2013-01-01

Cloud vertical structure is a key quantity in meteorological and climate studies, but it is also among the most difficult quantities to observe. In this study, we develop a long-term (10 years) radiosonde-based cloud profile product for the U.S. Department of Energy's Atmospheric Radiation Measurement (ARM) program Southern Great Plains (SGP), Tropical Western Pacific (TWP), and North Slope of Alaska (NSA) sites and a shorter-term product for the ARM Mobile Facility (AMF) deployed in Shouxian, Anhui Province, China (AMF-China). The AMF-China site was in operation from 14 May to 28 December 2008; the ARM sites have been collecting data for over 15 years. The Active Remote Sensing of Cloud (ARSCL) value-added product (VAP), which combines data from the 95-GHz W-band ARM Cloud Radar (WACR) and/or the 35-GHz Millimeter Microwave Cloud Radar (MMCR), is used in this study to validate the radiosonde-based cloud layer retrieval method. The performance of the radiosonde-based cloud layer retrieval method applied to data from different climate regimes is evaluated. Overall, cloud layers derived from the ARSCL VAP and radiosonde data agree very well at the SGP and AMF-China sites. At the TWP and NSA sites, the radiosonde tends to detect more cloud layers in the upper troposphere.

Creating Access Points to Instrument-Based Atmospheric Data: Perspectives from the ARM Metadata Manager

NASA Astrophysics Data System (ADS)

Troyan, D.

2016-12-01

The Atmospheric Radiation Measurement (ARM) program has been collecting data from instruments in diverse climate regions for nearly twenty-five years. These data are made available to all interested parties at no cost via specially designed tools found on the ARM website (www.arm.gov). Metadata is created and applied to the various datastreams to facilitate information retrieval using the ARM website, the ARM Data Discovery Tool, and data quality reporting tools. Over the last year, the Metadata Manager - a relatively new position within the ARM program - created two documents that summarize the state of ARM metadata processes: ARM Metadata Workflow, and ARM Metadata Standards. These documents serve as guides to the creation and management of ARM metadata. With many of ARM's data functions spread around the Department of Energy national laboratory complex and with many of the original architects of the metadata structure no longer working for ARM, there is increased importance on using these documents to resolve issues from data flow bottlenecks and inaccurate metadata to improving data discovery and organizing web pages. This presentation will provide some examples from the workflow and standards documents. The examples will illustrate the complexity of the ARM metadata processes and the efficiency by which the metadata team works towards achieving the goal of providing access to data collected under the auspices of the ARM program.

Forecasting civil conflict along the shared socioeconomic pathways

NASA Astrophysics Data System (ADS)

Hegre, Håvard; Buhaug, Halvard; Calvin, Katherine V.; Nordkvelle, Jonas; Waldhoff, Stephanie T.; Gilmore, Elisabeth

2016-05-01

Climate change and armed civil conflict are both linked to socioeconomic development, although conditions that facilitate peace may not necessarily facilitate mitigation and adaptation to climate change. While economic growth lowers the risk of conflict, it is generally associated with increased greenhouse gas emissions and costs of climate mitigation policies. This study investigates the links between growth, climate change, and conflict by simulating future civil conflict using new scenario data for five alternative socioeconomic pathways with different mitigation and adaptation assumptions, known as the shared socioeconomic pathways (SSPs). We develop a statistical model of the historical effect of key socioeconomic variables on country-specific conflict incidence, 1960-2013. We then forecast the annual incidence of conflict, 2014-2100, along the five SSPs. We find that SSPs with high investments in broad societal development are associated with the largest reduction in conflict risk. This is most pronounced for the least developed countries—poverty alleviation and human capital investments in poor countries are much more effective instruments to attain global peace and stability than further improvements to wealthier economies. Moreover, the SSP that describes a sustainability pathway, which poses the lowest climate change challenges, is as conducive to global peace as the conventional development pathway.

Cortical Spiking Network Interfaced with Virtual Musculoskeletal Arm and Robotic Arm.

PubMed

Dura-Bernal, Salvador; Zhou, Xianlian; Neymotin, Samuel A; Przekwas, Andrzej; Francis, Joseph T; Lytton, William W

2015-01-01

Embedding computational models in the physical world is a critical step towards constraining their behavior and building practical applications. Here we aim to drive a realistic musculoskeletal arm model using a biomimetic cortical spiking model, and make a robot arm reproduce the same trajectories in real time. Our cortical model consisted of a 3-layered cortex, composed of several hundred spiking model-neurons, which display physiologically realistic dynamics. We interconnected the cortical model to a two-joint musculoskeletal model of a human arm, with realistic anatomical and biomechanical properties. The virtual arm received muscle excitations from the neuronal model, and fed back proprioceptive information, forming a closed-loop system. The cortical model was trained using spike timing-dependent reinforcement learning to drive the virtual arm in a 2D reaching task. Limb position was used to simultaneously control a robot arm using an improved network interface. Virtual arm muscle activations responded to motoneuron firing rates, with virtual arm muscles lengths encoded via population coding in the proprioceptive population. After training, the virtual arm performed reaching movements which were smoother and more realistic than those obtained using a simplistic arm model. This system provided access to both spiking network properties and to arm biophysical properties, including muscle forces. The use of a musculoskeletal virtual arm and the improved control system allowed the robot arm to perform movements which were smoother than those reported in our previous paper using a simplistic arm. This work provides a novel approach consisting of bidirectionally connecting a cortical model to a realistic virtual arm, and using the system output to drive a robotic arm in real time. Our techniques are applicable to the future development of brain neuroprosthetic control systems, and may enable enhanced brain-machine interfaces with the possibility for finer control of limb prosthetics.

Application of microwave radiometry to improving climate data records.

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

Liljegren, J. C.; Cadeddu, M. P.; Decision and Information Sciences

2007-01-01

Microwave radiometers deployed by the U. S. Department of Energy's Atmospheric Radiation Measurement (ARM) Program provide crucial data for a wide range of research applications. The accuracy and stability of these instruments also makes them ideal for improving climate data records: to detect and correct discontinuities in the long-term climate records, to validate and calibrate the climate data, to characterize errors in the climate records, and to plan for the future Global Climate Observing System (GCOS) Reference Upper-Air network. This paper presents an overview of these capabilities with examples from ARM data. Two-channel microwave radiometers (MWR) operating at 23.8 andmore » 31.4 GHz are deployed at each of eleven ARM Climate Research Facility (ACRF) field sites in the U.S. Southern Great Plains (SGP), Tropical Western Pacific (TWP), North Slope of Alaska (NSA), and with the ARM Mobile Facility in Niamey, Niger for the purpose of retrieving precipitable water vapor (PWV) and liquid water path (LWP). At these locations PWV ranges from as low as 1 mm (1 kg/m{sup 2}) at the NSA to 70 mm or more in the TWP; LWP can exceed 2 mm at many sites. The MWR accommodates this wide dynamic range for all non-precipitating conditions with a root-mean-square error of about 0.4 mm for PWV and 0.02 mm (20 g/m{sup 2}) for LWP. The calibration of the MWR is continuously and autonomously monitored and updated to maintain accuracy. Comparisons of collocated MWRs will be presented. Site-specific linear statistical retrievals are used operationally; more sophisticated retrievals are applied in post-processing the data. Because PWV is an integral measure, derived from both the relative humidity and temperature profiles of the radiosonde, it is a particularly useful reference quantity. Comparison of PWV measured by the MWR with PWV from radiosondes reveals dry biases and diurnal trends as well as general calibration variability in the radiosondes. To correct the bias and reduce the variability ARM scales the relative humidity measurements from the radiosondes to produce agreement with the PWV measured by the MWR. Comparisons of infrared spectral radiances calculated using these scaled radiosondes with high spectral resolution measurements exhibit dramatically reduced bias and variability. This ability to detect and correct errors in the radiosondes measurements will be critical for detecting climate change. The MWR has also been used for a variety of ground- and satellite-based remote sensor retrieval development and validation studies, including precipitable water vapor and slant water vapor retrievals using the Global Positioning System (GPS). The MWR can provide a valuable comparison for GPS-derived zenith wet delay and PWV values, e.g., for evaluating improved mapping functions and detecting errors due, for example, to multi-path contributions. For precipitable water vapor amounts less than 4 mm, which commonly occur in cold, dry Arctic conditions, the 0.4 mm root-mean-square error of the MWR precipitable water vapor measurement is problematic. To obtain increased sensitivity under these conditions, a new G-band water vapor radiometer (GVR) operating at 183.31 {+-} 1, {+-}3, {+-}7, and {+-}14 GHz is deployed at the NSA Barrow site. The GVR offers a valuable reference for radiosonde and GPS water vapor measurements at Arctic locations that are expected to be particularly sensitive to climate change.« less

RACORO continental boundary layer cloud investigations. 3. Separation of parameterization biases in single-column model CAM5 simulations of shallow cumulus

DOE PAGES

Lin, Wuyin; Liu, Yangang; Vogelmann, Andrew M.; ...

2015-06-19

Climatically important low-level clouds are commonly misrepresented in climate models. The FAst-physics System TEstbed and Research (FASTER) project has constructed case studies from the Atmospheric Radiation Measurement (ARM) Climate Research Facility's Southern Great Plain site during the RACORO aircraft campaign to facilitate research on model representation of boundary-layer clouds. This paper focuses on using the single-column Community Atmosphere Model version 5 (SCAM5) simulations of a multi-day continental shallow cumulus case to identify specific parameterization causes of low-cloud biases. Consistent model biases among the simulations driven by a set of alternative forcings suggest that uncertainty in the forcing plays only amore » relatively minor role. In-depth analysis reveals that the model's shallow cumulus convection scheme tends to significantly under-produce clouds during the times when shallow cumuli exist in the observations, while the deep convective and stratiform cloud schemes significantly over-produce low-level clouds throughout the day. The links between model biases and the underlying assumptions of the shallow cumulus scheme are further diagnosed with the aid of large-eddy simulations and aircraft measurements, and by suppressing the triggering of the deep convection scheme. It is found that the weak boundary layer turbulence simulated is directly responsible for the weak cumulus activity and the simulated boundary layer stratiform clouds. Increased vertical and temporal resolutions are shown to lead to stronger boundary layer turbulence and reduction of low-cloud biases.« less

Completion of spectral rotating shadowband radiometers and analysis of ARM spectral short-wave data. Technical progress report, November 1, 1994--October 31, 1995

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

Michalsky, J.; Harrison, L.

1995-04-26

The authors goal in the ARM program is the improvement of radiation models used in GCMs, especially in the shortwave, (1) by providing improved shortwave radiometric measurements for the testing of models and (2) by developing methods for retrieving climatologically sensitive parameters that serve as input to shortwave and longwave models. They are acquiring downwelling direct and diffuse spectral irradiance, at six wavelengths, plus downwelling broadband longwave, and upwelling and downwelling broadband shortwave irradiances that they combined with surface and upper air data from the Albany airport as a test data set for ARM modelers. They have also developed algorithmsmore » to improve shortwave measurements made at the Southern Great Plains (SGP) ARM site by standard thermopile instruments and by the multifolter rotating shadowband radiometer (MFRSR). However, the major objective of the program has been the development of two spectral versions of the rotating shadowband radiometer. The MFRSR, has become a workhose at the CART site in Oklahoma and Kansas, and it is widely deployed in other climate programs. They have spent most of their effort this year developing techniques to retrieve column aerosol, water vapor, and ozone from direct beam spectral measurements of the MFRSR. Additionally, they have had success in calculating shortwave surface albedo and aerosol optical depth from the ratio of direct to diffuse spectral irradiance. Using the surface albedo and the global irradiance, they have calculated cloud optical depths. From cloud optical depth and liquid water measured with the microwave radiometer, they have calculated effective liquid cloud particle radii. In each case the authors have attempted to validate the approach using independent measurements or retrievals of the parameters under investigation. With the exception of the ozone intercomparison, the corroborative measurements have been made at the SGP CART site. This report highlights these results.« less

Satellite Data Support for the ARM Climate Research Facility, 8/01/2009 - 7/31/2015

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

Minnis, Patrick; Khaiyer, Mandana M

This report summarizes the support provided by NASA Langley Research for the DOE ARM Program in the form of cloud and radiation products derived from satellite imager data for the period between 8/01/09 through 7/31/15. Cloud properties such as cloud amount, height, and optical depth as well as outgoing longwave and shortwave broadband radiative fluxes were derived from geostationary and low-earth orbiting satellite imager radiance measurements for domains encompassing ARM permanent sites and field campaigns during the performance period. Datasets provided and documents produced are listed.

What Goes Up Must Come Down: The Lifecycle of Convective Clouds (492nd Brookhaven Lecture)

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

Jensen, Michael

Some clouds look like cotton balls and others like anvils. Some bring rain, some snow and sleet, and others, just shade. But, whether big and billowy or dark and stormy, clouds affect far more than the weather each day. Armed with measurements of clouds’ updrafts and downdrafts—which resemble airflow in a convection oven—and many other atmospheric interactions, scientists from Brookhaven Lab and other institutions around the world are developing models that are crucial for understanding Earth’s climate and forecasting future climate change. During his lecture, Dr. Jensen provides an overview of the importance of clouds in the Earth’s climate systemmore » before explaining how convective clouds form, grow, and dissipate. His discussion includes findings from the Midlatitude Continental Convective Clouds Experiment (MC3E), a major collaborative experiment between U.S. Department of Energy (DOE) and NASA scientists to document precipitation, clouds, winds, and moisture in 3-D for a holistic view of convective clouds and their environment.« less

Final Report for Research Conducted at The Scripps Institution of Oceanography, University of California San Diego from 2/2002 to 8/2003 for ''Aerosol and Cloud-Field Radiative Effects in the Tropical Western Pacific: Analyses and General Circulation Model Parameterizations''

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

Vogelmann, A. M.

OAK-B135 Final report from the University of California San Diego for an ongoing research project that was moved to Brookhaven National Laboratory where proposed work will be completed. The research uses measurements made by the Atmospheric Radiation Measurement (ARM) Program to quantify the effects of aerosols and clouds on the Earth's energy balance in the climatically important Tropical Western Pacific.

Does infectious disease cause global variation in the frequency of intrastate armed conflict and civil war?

PubMed

Letendre, Kenneth; Fincher, Corey L; Thornhill, Randy

2010-08-01

Geographic and cross-national variation in the frequency of intrastate armed conflict and civil war is a subject of great interest. Previous theory on this variation has focused on the influence on human behaviour of climate, resource competition, national wealth, and cultural characteristics. We present the parasite-stress model of intrastate conflict, which unites previous work on the correlates of intrastate conflict by linking frequency of the outbreak of such conflict, including civil war, to the intensity of infectious disease across countries of the world. High intensity of infectious disease leads to the emergence of xenophobic and ethnocentric cultural norms. These cultures suffer greater poverty and deprivation due to the morbidity and mortality caused by disease, and as a result of decreased investment in public health and welfare. Resource competition among xenophobic and ethnocentric groups within a nation leads to increased frequency of civil war. We present support for the parasite-stress model with regression analyses. We find support for a direct effect of infectious disease on intrastate armed conflict, and support for an indirect effect of infectious disease on the incidence of civil war via its negative effect on national wealth. We consider the entanglements of feedback of conflict into further reduced wealth and increased incidence of disease, and discuss implications for international warfare and global patterns of wealth and imperialism.

Airborne observations of greenhouse gases in the North Slope of Alaska during summer 2015

NASA Astrophysics Data System (ADS)

Biraud, S.; Torn, M. S.; Sweeney, C.; Springston, S. R.; Sedlacek, A. J., III

2015-12-01

Atmospheric temperatures are warming faster in the Arctic than predicted by climate models. The impact of this warming on permafrost degradation is not well understood, but it is projected to increase carbon decomposition and greenhouse gas production (CO2 and/or CH4) by arctic ecosystems. Airborne observations of atmospheric trace gases, aerosols and cloud properties in North Slopes of Alaska (NSA) are improving our understanding of global climate, with the goal of reducing the uncertainty in global and regional climate simulations and projections. From June 1 through September 15, 2015, the Atmospheric radiation measurement (ARM) airborne facility (AAF) deployed a G1 research aircraft (ARM-ACME-V mission) to fly over the North Slope of Alaska, with occasional vertical profiling to measure trace gas concentrations, between Prudhoe Bay, Oliktok point, Barrow, Atqasuk, Ivotuk, and Toolik Lake. The aircraft payload includes a Picarro and a LGR analyzers for continuous measurements of CO2, CH4, H2O, and CO and N2O mixing ratios, and a 12-flask sampler for analysis of carbon cycle gases (CO2, CO, CH4, N2O, 13CO2, 14CO2, carbonyl sulfide, and trace hydrocarbon species including ethane). The aircraft payload also include measurements of aerosol properties (number size distribution, total number concentration, absorption, and scattering), cloud properties (droplet and ice size information), atmospheric thermodynamic state, and solar/infrared radiation. Preliminary results using CO2, CH4, CO, ethane, and soot spectroscopy observations are used to tease apart biogenic and thermogenic (biomass burning, and oil and gas production) contributions

ACME-V mission in the North Slope of Alaska (Airborne Carbon MEasurements)

NASA Astrophysics Data System (ADS)

Biraud, S.; Torn, M. S.; Sedlacek, A. J., III; Sweeney, C.; Springston, S. R.

2016-12-01

Atmospheric temperatures are warming faster in the Arctic than predicted by climate models. The impact of this warming on permafrost degradation is not well understood, but it is projected to increase carbon decomposition and greenhouse gas production (CO2 and/or CH4) by arctic ecosystems. Airborne observations of atmospheric trace gases, aerosols and cloud properties in North Slopes of Alaska (NSA) are improving our understanding of global climate, with the goal of reducing the uncertainty in global and regional climate simulations and projections. From June 1 through September 15, 2015, the Atmospheric radiation measurement (ARM) airborne facility (AAF) deployed a G1 research aircraft (ARM-ACME-V mission) to fly over the North Slope of Alaska, with occasional vertical profiling to measure trace gas concentrations, between Prudhoe Bay, Oliktok point, Barrow, Atqasuk, Ivotuk, and Toolik Lake. The aircraft payload includes a Picarro and a LGR analyzers for continuous measurements of CO2, CH4, H2O, and CO and N2O mixing ratios, and a 12-flask sampler for analysis of carbon cycle gases (CO2, CO, CH4, N2O, 13CO2, 14CO2, carbonyl sulfide, and trace hydrocarbon species including ethane). The aircraft payload also include measurements of aerosol properties (number size distribution, total number concentration, absorption, and scattering), cloud properties (droplet and ice size information), atmospheric thermodynamic state, and solar/infrared radiation. Preliminary results using CO2, CH4, CO, ethane, and soot spectroscopy observations are used to tease apart biogenic and thermogenic (biomass burning, and oil and gas production) contributions.

Comparison of Vaisala radiosondes RS41 and RS92 at the ARM Southern Great Plains site

DOE PAGES

Jensen, Michael P.; Holdridge, Donna J.; Survo, Petteri; ...

2016-07-20

In the fall of 2013, the Vaisala RS41 (fourth generation) radiosonde was introduced as a replacement for the RS92-SGP radiosonde with improvements in measurement accuracy of profiles of atmospheric temperature, humidity, and pressure. In order to help characterize these improvements, an intercomparison campaign was undertaken at the US Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facility site in north-central Oklahoma, USA. During 3–8 June 2014, a total of 20 twin-radiosonde flights were performed in a variety of atmospheric conditions representing typical midlatitude continental summertime conditions. The results show that for most of the observed conditions the RS92 andmore » RS41 measurements agree much better than the manufacturer-specified combined uncertainties with notable exceptions when exiting liquid cloud layers where the “wet-bulbing” effect appears to be mitigated for several cases in the RS41 observations. The RS41 measurements of temperature and humidity, with applied correction algorithms, also appear to show less sensitivity to solar heating. In addition, these results suggest that the RS41 does provide important improvements, particularly in cloudy conditions. For many science applications – such as atmospheric process studies, retrieval development, and weather forecasting and climate modeling – the differences between the RS92 and RS41 measurements should have little impact. However, for long-term trend analysis and other climate applications, additional characterization of the RS41 measurements and their relation to the long-term observational records will be required.« less

Architectures for Rainfall Property Estimation From Polarimetric Radar

NASA Astrophysics Data System (ADS)

Collis, S. M.; Giangrande, S. E.; Helmus, J.; Troemel, S.

2014-12-01

Radars that transmit and receive signals in polarizations aligned both horizontal and vertical to the horizon collect a number of measurements. The relation both between these measurements and between measurements and desired microphysical quantities (such as rainfall rate) is complicated due to a number of scattering mechanisms. The result is that there ends up being an intractable number of often incompatible techniques for extracting geophysical insight. This presentation will discuss methods developed by the Atmospheric Measurement Climate (ARM) Research Facility to streamline the creation of application chains for retrieving rainfall properties for the purposes of fine scale model evaluation. By using a Common Data Model (CDM) approach and working in the popular open source Python scientific environment analysis techniques such as Linear Programming (LP) can be bought to bear on the task of retrieving insight from radar signals. This presentation will outline how we have used these techniques to detangle polarimetric phase signals, estimate a three-dimensional precipitation field and then objectively compare to cloud resolving model derived rainfall fields from the NASA/DoE Mid-Latitude Continental Convective Clouds Experiment (MC3E). All techniques show will be available, open source, in the Python-ARM Radar Toolkit (Py-ART).

Cortical Spiking Network Interfaced with Virtual Musculoskeletal Arm and Robotic Arm

PubMed Central

Dura-Bernal, Salvador; Zhou, Xianlian; Neymotin, Samuel A.; Przekwas, Andrzej; Francis, Joseph T.; Lytton, William W.

2015-01-01

Embedding computational models in the physical world is a critical step towards constraining their behavior and building practical applications. Here we aim to drive a realistic musculoskeletal arm model using a biomimetic cortical spiking model, and make a robot arm reproduce the same trajectories in real time. Our cortical model consisted of a 3-layered cortex, composed of several hundred spiking model-neurons, which display physiologically realistic dynamics. We interconnected the cortical model to a two-joint musculoskeletal model of a human arm, with realistic anatomical and biomechanical properties. The virtual arm received muscle excitations from the neuronal model, and fed back proprioceptive information, forming a closed-loop system. The cortical model was trained using spike timing-dependent reinforcement learning to drive the virtual arm in a 2D reaching task. Limb position was used to simultaneously control a robot arm using an improved network interface. Virtual arm muscle activations responded to motoneuron firing rates, with virtual arm muscles lengths encoded via population coding in the proprioceptive population. After training, the virtual arm performed reaching movements which were smoother and more realistic than those obtained using a simplistic arm model. This system provided access to both spiking network properties and to arm biophysical properties, including muscle forces. The use of a musculoskeletal virtual arm and the improved control system allowed the robot arm to perform movements which were smoother than those reported in our previous paper using a simplistic arm. This work provides a novel approach consisting of bidirectionally connecting a cortical model to a realistic virtual arm, and using the system output to drive a robotic arm in real time. Our techniques are applicable to the future development of brain neuroprosthetic control systems, and may enable enhanced brain-machine interfaces with the possibility for finer control of limb prosthetics. PMID:26635598

ARM Climate Research Facility: Outreach Tools and Strategies

NASA Astrophysics Data System (ADS)

Roeder, L.; Jundt, R.

2009-12-01

Sponsored by the Department of Energy, the ARM Climate Research Facility is a global scientific user facility for the study of climate change. To publicize progress and achievements and to reach new users, the ACRF uses a variety of Web 2.0 tools and strategies that build off of the program’s comprehensive and well established News Center (www.arm.gov/news). These strategies include: an RSS subscription service for specific news categories; an email “newsletter” distribution to the user community that compiles the latest News Center updates into a short summary with links; and a Facebook page that pulls information from the News Center and links to relevant information in other online venues, including those of our collaborators. The ACRF also interacts with users through field campaign blogs, like Discovery Channel’s EarthLive, to share research experiences from the field. Increasingly, field campaign Wikis are established to help ACRF researchers collaborate during the planning and implementation phases of their field studies and include easy to use logs and image libraries to help record the campaigns. This vital reference information is used in developing outreach material that is shared in highlights, news, and Facebook. Other Web 2.0 tools that ACRF uses include Google Maps to help users visualize facility locations and aircraft flight patterns. Easy-to-use comment boxes are also available on many of the data-related web pages on www.arm.gov to encourage feedback. To provide additional opportunities for increased interaction with the public and user community, future Web 2.0 plans under consideration for ACRF include: evaluating field campaigns for Twitter and microblogging opportunities, adding public discussion forums to research highlight web pages, moving existing photos into albums on FlickR or Facebook, and building online video archives through YouTube.

The Impact of ARM on Climate Modeling. Chapter 26

NASA Technical Reports Server (NTRS)

Randall, David A.; Del Genio, Anthony D.; Donner, Leo J.; Collins, William D.; Klein, Stephen A.

2016-01-01

Climate models are among humanity's most ambitious and elaborate creations. They are designed to simulate the interactions of the atmosphere, ocean, land surface, and cryosphere on time scales far beyond the limits of deterministic predictability, and including the effects of time-dependent external forcings. The processes involved include radiative transfer, fluid dynamics, microphysics, and some aspects of geochemistry, biology, and ecology. The models explicitly simulate processes on spatial scales ranging from the circumference of the Earth down to one hundred kilometers or smaller, and implicitly include the effects of processes on even smaller scales down to a micron or so. The atmospheric component of a climate model can be called an atmospheric global circulation model (AGCM). In an AGCM, calculations are done on a three-dimensional grid, which in some of today's climate models consists of several million grid cells. For each grid cell, about a dozen variables are time-stepped as the model integrates forward from its initial conditions. These so-called prognostic variables have special importance because they are the only things that a model remembers from one time step to the next; everything else is recreated on each time step by starting from the prognostic variables and the boundary conditions. The prognostic variables typically include information about the mass of dry air, the temperature, the wind components, water vapor, various condensed-water species, and at least a few chemical species such as ozone. A good way to understand how climate models work is to consider the lengthy and complex process used to develop one. Lets imagine that a new AGCM is to be created, starting from a blank piece of paper. The model may be intended for a particular class of applications, e.g., high-resolution simulations on time scales of a few decades. Before a single line of code is written, the conceptual foundation of the model must be designed through a creative envisioning that starts from the intended application and is based on current understanding of how the atmosphere works and the inventory of mathematical methods available.

Surface Energy Balance System (SEBS) Handbook

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

Cook, D. R.

2016-01-01

A Surface Energy Balance System (SEBS) has been installed collocated with each deployed Eddy Correlation Flux Measurement System (ECOR) at the Atmospheric Radiation Measurement (ARM) Climate Research Facility’s Southern Great Plains (SGP) site, North Slope of Alaska (NSA) site, first ARM Mobile Facility (AMF1), second ARM Mobile Facility (AMF2), and third ARM Mobile Facility (AMF3) at Oliktok Point (OLI). A SEBS was also deployed with the Tropical Western Pacific (TWP) site, before it was decommissioned. Data from these sites, including the retired TWP, are available in the ARM Data Archive. The SEBS consists of upwelling and downwelling solar and infraredmore » radiometers within one net radiometer, a wetness sensor, and soil measurements. The SEBS measurements allow the comparison of ECOR sensible and latent heat fluxes with the energy balance determined from the SEBS and provide information on wetting of the sensors for data quality purposes.« less

Atmospheric Radiation Measurement Program facilities newsletter, January 2000

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

Sisterson, D.L.

2000-02-16

The subject of this newsletter is the ARM unmanned aerospace vehicle program. The ARM Program's focus is on climate research, specifically research related to solar radiation and its interaction with clouds. The SGP CART site contains highly sophisticated surface instrumentation, but even these instruments cannot gather some crucial climate data from high in the atmosphere. The Department of Energy and the Department of Defense joined together to use a high-tech, high-altitude, long-endurance class of unmanned aircraft known as the unmanned aerospace vehicle (UAV). A UAV is a small, lightweight airplane that is controlled remotely from the ground. A pilot sitsmore » in a ground-based cockpit and flies the aircraft as if he were actually on board. The UAV can also fly completely on its own through the use of preprogrammed computer flight routines. The ARM UAV is fitted with payload instruments developed to make highly accurate measurements of atmospheric flux, radiance, and clouds. Using a UAV is beneficial to climate research in many ways. The UAV puts the instrumentation within the environment being studied and gives scientists direct measurements, in contrast to indirect measurements from satellites orbiting high above Earth. The data collected by UAVs can be used to verify and calibrate measurements and calculated values from satellites, therefore making satellite data more useful and valuable to researchers.« less

Soil Water and Temperature System (SWATS) Instrument Handbook

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

Cook, David R.

2016-04-01

The soil water and temperature system (SWATS) provides vertical profiles of soil temperature, soil-water potential, and soil moisture as a function of depth below the ground surface at hourly intervals. The temperature profiles are measured directly by in situ sensors at the Central Facility and many of the extended facilities of the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility Southern Great Plains (SGP) site. The soil-water potential and soil moisture profiles are derived from measurements of soil temperature rise in response to small inputs of heat. Atmospheric scientists use the data in climate models tomore » determine boundary conditions and to estimate the surface energy flux. The data are also useful to hydrologists, soil scientists, and agricultural scientists for determining the state of the soil.« less

Final Report for “Simulating the Arctic Winter Longwave Indirect Effects. A New Parameterization for Frost Flower Aerosol Salt Emissions” (DESC0006679) for 9/15/2011 through 9/14/2015

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

Russell, Lynn M.; Somerville, Richard C.J.; Burrows, Susannah

Description of the Project: This project has improved the aerosol formulation in a global climate model by using innovative new field and laboratory observations to develop and implement a novel wind-driven sea ice aerosol flux parameterization. This work fills a critical gap in the understanding of clouds, aerosol, and radiation in polar regions by addressing one of the largest missing particle sources in aerosol-climate modeling. Recent measurements of Arctic organic and inorganic aerosol indicate that the largest source of natural aerosol during the Arctic winter is emitted from crystal structures, known as frost flowers, formed on a newly frozen seamore » ice surface [Shaw et al., 2010]. We have implemented the new parameterization in an updated climate model making it the first capable of investigating how polar natural aerosol-cloud indirect effects relate to this important and previously unrecognized sea ice source. The parameterization is constrained by Arctic ARM in situ cloud and radiation data. The modified climate model has been used to quantify the potential pan-Arctic radiative forcing and aerosol indirect effects due to this missing source. This research supported the work of one postdoc (Li Xu) for two years and contributed to the training and research of an undergraduate student. This research allowed us to establish a collaboration between SIO and PNNL in order to contribute the frost flower parameterization to the new ACME model. One peer-reviewed publications has already resulted from this work, and a manuscript for a second publication has been completed. Additional publications from the PNNL collaboration are expected to follow.« less

Effects of spiral arms on star formation in nuclear rings of barred-spiral galaxies

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

Seo, Woo-Young; Kim, Woong-Tae, E-mail: seowy@astro.snu.ac.kr, E-mail: wkim@astro.snu.ac.kr

2014-09-01

We use hydrodynamic simulations to study the effect of spiral arms on the star formation rate (SFR) in nuclear rings of barred-spiral galaxies. We find that spiral arms can be an efficient means of gas transport from the outskirts to the central parts, provided that the arms are rotating slower than the bar. While the ring star formation in models with no arms or corotating arms is active only during around the bar growth phase, arm-driven gas accretion both significantly enhances and prolongs the ring star formation in models with slow-rotating arms. The arm-enhanced SFR is larger by a factormore » of ∼3-20 than in the no-arm model, with larger values corresponding to stronger and slower arms. Arm-induced mass inflows also make dust lanes stronger. Nuclear rings in slow-arm models are ∼45% larger than in the no-arm counterparts. Star clusters that form in a nuclear ring exhibit an age gradient in the azimuthal direction only when the SFR is small, whereas no notable age gradient is found in the radial direction for models with arm-induced star formation.« less

Enhanced Soundings for Local Coupling Studies Field Campaign Report

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

Ferguson, Craig R; Santanello, Joseph A; Gentine, Pierre

This document presents initial analyses of the enhanced radiosonde observations obtained during the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility Enhanced Soundings for Local Coupling Studies Field Campaign (ESLCS), which took place at the ARM Southern Great Plains (SGP) Central Facility (CF) from June 15 to August 31, 2015. During ESLCS, routine 4-times-daily radiosonde measurements at the ARM-SGP CF were augmented on 12 days (June 18 and 29; July 11, 14, 19, and 26; August 15, 16, 21, 25, 26, and 27) with daytime 1-hourly radiosondes and 10-minute ‘trailer’ radiosondes every 3 hours. These 12more » intensive operational period (IOP) days were selected on the basis of prior-day qualitative forecasts of potential land-atmosphere coupling strength. The campaign captured 2 dry soil convection advantage days (June 29 and July 14) and 10 atmospherically controlled days. Other noteworthy IOP events include: 2 soil dry-down sequences (July 11-14-19 and August 21-25-26), a 2-day clear-sky case (August 15-16), and the passing of Tropical Storm Bill (June 18). To date, the ESLCS data set constitutes the highest-temporal-resolution sampling of the evolution of the daytime planetary boundary layer (PBL) using radiosondes at the ARM-SGP. The data set is expected to contribute to: 1) improved understanding and modeling of the diurnal evolution of the PBL, particularly with regard to the role of local soil wetness, and (2) new insights into the appropriateness of current ARM-SGP CF thermodynamic sampling strategies.« less

Asia-Pacific Center for Security Studies, Annual Report 2009

DTIC Science & Technology

2009-01-01

International financial crisis Global warning/ climate change Pandemic disease Drug trafficking Illegal migration Piracy Terrorism Arms smuggling Illegal...Resource scarcity/rivalry Global warming/ climate change Drug trafficing Illegal fishing Crime Territorial disputes Pandemic disease Government...APCSS. March 2009. <http://www.apcss.org/Publications/da vis2009governanceInChina2010. pdf > hashmi, Taj, “Emerging Changes in America’s Pakistan Policy

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

Palanisamy, Giri

The U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility performs routine in situ and remote-sensing observations to provide a detailed and accurate description of the Earth atmosphere in diverse climate regimes. The result is a huge archive of diverse data sets containing observational and derived data, currently accumulating at a rate of 30 terabytes (TB) of data and 150,000 different files per month (http://www.archive.arm.gov/stats/). Continuing the current processing while scaling this to even larger sizes is extremely important to the ARM Facility and requires consistent metadata and data standards. The standards described in this document willmore » enable development of automated analysis and discovery tools for the ever growing data volumes. It will enable consistent analysis of the multiyear data, allow for development of automated monitoring and data health status tools, and allow future capabilities of delivering data on demand that can be tailored explicitly for the user needs. This analysis ability will only be possible if the data follows a minimum set of standards. This document proposes a hierarchy of required and recommended standards.« less

Southern Great Plains Safety Orientation

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

Schatz, John

2014-05-01

Welcome to the Atmospheric Radiation Measurement (ARM) Climate Research Facility (ARM) Southern Great Plains (SGP) site. This U.S. Department of Energy (DOE) site is managed by Argonne National Laboratory (ANL). It is very important that all visitors comply with all DOE and ANL safety requirements, as well as those of the Occupational Safety and Health Administration (OSHA), the National Fire Protection Association, and the U.S. Environmental Protection Agency, and with other requirements as applicable.

Employment of the El Salvador Armed Forces for Internal Security

DTIC Science & Technology

2011-02-02

and in which the familiar life develops undressed of the fear; a country where a climate exists that favors the investment and the opportunities of...armed forces the experience and familiarize them with the roots of the problems, causes, and conditions that generate the violence in the country...police, military and fiscal members, and members of other institutions involved in the combating of crime have to be familiar with the legal procedures

United States-Philippines Bases Agreements: Prospect for its Renewal

DTIC Science & Technology

1988-05-01

its armed forces, public vessels, or aircraft in the Pacific."(9:7) The Korean conflict effectively changed the nature of the conflict in which the...helps the local economy. Military equipment, training in the US, conferences, e- changes , and joint exercises help to modernize the Philippine Armed...gave a good and profitable investment climate for Americans. (8:60-61) It was not surprising that while biq businesses were owned by Americans, small

ARM User Survey Report: Data Access, Quality, and Delivery

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

Mather, JH; Roeder, LR; Sivaraman, C

The objective of this survey was to obtain user feedback to determine how users of the Atmospheric Radiation Measurement (ARM) Climate Research Facility Data Archive interact with the more than 2000 available types of datastreams. The survey also gathered information about data discovery and data quality. The Market and Competitive Analysis group at Pacific Northwest National Laboratory worked with web administrators to develop a landing page from which users could access the survey. A survey invitation was sent by ARM via email to about 6100 users on February 22, 2012. The invitation was also posted on the ARM website andmore » Facebook page. Reminders were sent via e-mail and posted on Facebook while the survey was open, February 22-March 23, 2012.« less

Evaluation of high-level clouds in cloud resolving model simulations with ARM and KWAJEX observations

DOE PAGES

Liu, Zheng; Muhlbauer, Andreas; Ackerman, Thomas

2015-11-05

In this paper, we evaluate high-level clouds in a cloud resolving model during two convective cases, ARM9707 and KWAJEX. The simulated joint histograms of cloud occurrence and radar reflectivity compare well with cloud radar and satellite observations when using a two-moment microphysics scheme. However, simulations performed with a single moment microphysical scheme exhibit low biases of approximately 20 dB. During convective events, two-moment microphysical overestimate the amount of high-level cloud and one-moment microphysics precipitate too readily and underestimate the amount and height of high-level cloud. For ARM9707, persistent large positive biases in high-level cloud are found, which are not sensitivemore » to changes in ice particle fall velocity and ice nuclei number concentration in the two-moment microphysics. These biases are caused by biases in large-scale forcing and maintained by the periodic lateral boundary conditions. The combined effects include significant biases in high-level cloud amount, radiation, and high sensitivity of cloud amount to nudging time scale in both convective cases. The high sensitivity of high-level cloud amount to the thermodynamic nudging time scale suggests that thermodynamic nudging can be a powerful ‘‘tuning’’ parameter for the simulated cloud and radiation but should be applied with caution. The role of the periodic lateral boundary conditions in reinforcing the biases in cloud and radiation suggests that reducing the uncertainty in the large-scale forcing in high levels is important for similar convective cases and has far reaching implications for simulating high-level clouds in super-parameterized global climate models such as the multiscale modeling framework.« less

Forecasting civil conflict along the shared socioeconomic pathways

DOE PAGES

Hegre, Håvard; Buhaug, Halvard; Calvin, Katherine V.; ...

2016-04-25

Climate change and armed civil conflict are both linked to socioeconomic development, although conditions that facilitate peace may not necessarily facilitate mitigation and adaptation to climate change. While economic growth lowers the risk of conflict, it is generally associated with increased greenhouse gas emissions and costs of climate mitigation policies. Here, this study investigates the links between growth, climate change, and conflict by simulating future civil conflict using new scenario data for five alternative socioeconomic pathways with different mitigation and adaptation assumptions, known as the shared socioeconomic pathways (SSPs). We develop a statistical model of the historical effect of keymore » socioeconomic variables on country-specific conflict incidence, 1960–2013. We then forecast the annual incidence of conflict, 2014–2100, along the five SSPs. We find that SSPs with high investments in broad societal development are associated with the largest reduction in conflict risk. This is most pronounced for the least developed countries—poverty alleviation and human capital investments in poor countries are much more effective instruments to attain global peace and stability than further improvements to wealthier economies. Moreover, the SSP that describes a sustainability pathway, which poses the lowest climate change challenges, is as conducive to global peace as the conventional development pathway.« less

Forecasting civil conflict along the shared socioeconomic pathways

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

Hegre, Håvard; Buhaug, Halvard; Calvin, Katherine V.

Climate change and armed civil conflict are both linked to socioeconomic development, although conditions that facilitate peace may not necessarily facilitate mitigation and adaptation to climate change. While economic growth lowers the risk of conflict, it is generally associated with increased greenhouse gas emissions and costs of climate mitigation policies. Here, this study investigates the links between growth, climate change, and conflict by simulating future civil conflict using new scenario data for five alternative socioeconomic pathways with different mitigation and adaptation assumptions, known as the shared socioeconomic pathways (SSPs). We develop a statistical model of the historical effect of keymore » socioeconomic variables on country-specific conflict incidence, 1960–2013. We then forecast the annual incidence of conflict, 2014–2100, along the five SSPs. We find that SSPs with high investments in broad societal development are associated with the largest reduction in conflict risk. This is most pronounced for the least developed countries—poverty alleviation and human capital investments in poor countries are much more effective instruments to attain global peace and stability than further improvements to wealthier economies. Moreover, the SSP that describes a sustainability pathway, which poses the lowest climate change challenges, is as conducive to global peace as the conventional development pathway.« less

Evaluation of cloud fraction and its radiative effect simulated by IPCC AR4 global models against ARM surface observations

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

Qian, Yun; Long, Charles N.; Wang, Hailong

2012-02-17

Cloud Fraction (CF) is the dominant modulator of radiative fluxes. In this study, we evaluate CF simulations in the IPCC AR4 GCMs against ARM ground measurements, with a focus on the vertical structure, total amount of cloud and its effect on cloud shortwave transmissivity, for both inter-model deviation and model-measurement discrepancy. Our intercomparisons of three CF or sky-cover related dataset reveal that the relative differences are usually less than 10% (5%) for multi-year monthly (annual) mean values, while daily differences are quite significant. The results also show that the model-observation and the inter-model deviations have a similar magnitude for themore » total CF (TCF) and the normalized cloud effect, and they are twice as large as the surface downward solar radiation and cloud transmissivity. This implies that the other cloud properties, such as cloud optical depth and height, have a similar magnitude of disparity to TCF among the GCMs, and suggests that a better agreement among the GCMs in solar radiative fluxes could be the result of compensating errors in either cloud vertical structure, cloud optical depth or cloud fraction. Similar deviation pattern between inter-model and model-measurement suggests that the climate models tend to generate larger bias against observations for those variables with larger inter-model deviation. The simulated TCF from IPCC AR4 GCMs are very scattered through all seasons over three ARM sites: Southern Great Plains (SGP), Manus, Papua New Guinea and North Slope of Alaska (NSA). The GCMs perform better at SGP than at Manus and NSA in simulating the seasonal variation and probability distribution of TCF; however, the TCF in these models is remarkably underpredicted and cloud transmissivity is less susceptible to the change of TCF than the observed at SGP. Much larger inter-model deviation and model bias are found over NSA than the other sites in estimating the TCF, cloud transmissivity and cloud-radiation interaction, suggesting that the Arctic region continues to challenge cloud simulations in climate models. Most of the GCMs tend to underpredict CF and fail to capture the seasonal variation of CF at middle and low levels in the tropics. The high altitude CF is much larger in the GCMs than the observation and the inter-model variability of CF also reaches maximum at high levels in the tropics. Most of the GCMs tend to underpredict CF by 50-150% relative to the measurement average at low and middle levels over SGP. While the GCMs generally capture the maximum CF in the boundary layer and vertical variability, the inter-model deviation is largest near surface over the Arctic. The internal variability of CF simulated in ensemble runs with the same model is very minimal.« less

Using the Atmospheric Radiation Measurement (ARM) Datasets to Evaluate Climate Models in Simulating Diurnal and Seasonal Variations of Tropical Clouds

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

Wang, Hailong; Burleyson, Casey D.; Ma, Po-Lun

We use the long-term Atmospheric Radiation Measurement (ARM) datasets collected at the three Tropical Western Pacific (TWP) sites as a tropical testbed to evaluate the ability of the Community Atmosphere Model (CAM5) to simulate the various types of clouds, their seasonal and diurnal variations, and their impact on surface radiation. We conducted a series of CAM5 simulations at various horizontal grid spacing (around 2°, 1°, 0.5°, and 0.25°) with meteorological constraints from reanalysis. Model biases in the seasonal cycle of cloudiness are found to be weakly dependent on model resolution. Positive biases (up to 20%) in the annual mean totalmore » cloud fraction appear mostly in stratiform ice clouds. Higher-resolution simulations do reduce the positive bias in the frequency of ice clouds, but they inadvertently increase the negative biases in convective clouds and low-level liquid clouds, leading to a positive bias in annual mean shortwave fluxes at the sites, as high as 65 W m-2 in the 0.25° simulation. Such resolution-dependent biases in clouds can adversely lead to biases in ambient thermodynamic properties and, in turn, feedback on clouds. Both the CAM5 model and ARM observations show distinct diurnal cycles in total, stratiform and convective cloud fractions; however, they are out-of-phase by 12 hours and the biases vary by site. Our results suggest that biases in deep convection affect the vertical distribution and diurnal cycle of stratiform clouds through the transport of vapor and/or the detrainment of liquid and ice. We also found that the modelled gridmean surface longwave fluxes are systematically larger than site measurements when the grid that the ARM sites reside in is partially covered by ocean. The modeled longwave fluxes at such sites also lack a discernable diurnal cycle because the ocean part of the grid is warmer and less sensitive to radiative heating/cooling compared to land. Higher spatial resolution is more helpful is this regard. Our testbed approach can be easily adapted for the evaluation of new parameterizations being developed for CAM5 or other global or regional model simulations at high spatial resolutions.« less

Tools for Teaching Climate Change Studies

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

Maestas, A.M.; Jones, L.A.

2005-03-18

The Atmospheric Radiation Measurement Climate Research Facility (ACRF) develops public outreach materials and educational resources for schools. Studies prove that science education in rural and indigenous communities improves when educators integrate regional knowledge of climate and environmental issues into school curriculum and public outreach materials. In order to promote understanding of ACRF climate change studies, ACRF Education and Outreach has developed interactive kiosks about climate change for host communities close to the research sites. A kiosk for the North Slope of Alaska (NSA) community was installed at the Iupiat Heritage Center in 2003, and a kiosk for the Tropical Westernmore » Pacific locales will be installed in 2005. The kiosks feature interviews with local community elders, regional agency officials, and Atmospheric Radiation Measurement (ARM) Program scientists, which highlight both research and local observations of some aspects of environmental and climatic change in the Arctic and Pacific. The kiosks offer viewers a unique opportunity to learn about the environmental concerns and knowledge of respected community elders, and to also understand state-of-the-art climate research. An archive of interviews from the communities will also be distributed with supplemental lessons and activities to encourage teachers and students to compare and contrast climate change studies and oral history observations from two distinct locations. The U.S. Department of Energy's ACRF supports education and outreach efforts for communities and schools located near its sites. ACRF Education and Outreach has developed interactive kiosks at the request of the communities to provide an opportunity for the public to learn about climate change from both scientific and indigenous perspectives. Kiosks include interviews with ARM scientists and provide users with basic information about climate change studies as well as interviews with elders and community leaders discussing the impacts of climate change on land, sea, and other aspects of village life.« less

Arctic Black Carbon Loading and Profile Using the Single-Particle Soot Photometer (SP2) Field Campaign Report

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

Sedlacek, Arthur J

One of the major issues confronting aerosol climate simulations of the Arctic and Antarctic cryospheres is the lack of detailed data on the vertical and spatial distribution of aerosols with which to test these models. This is due, in part, to the inherent difficulty of conducting such measurements in extreme environments. However given the pronounced sensitivity of the polar regions to radiative balance perturbations, it is incumbent upon our community to better understand and quantify these perturbations, and their unique feedbacks, so that robust model predictions of this region can be realized. One class of under-measured radiative forcing agents inmore » the polar region is the absorbing aerosol—black carbon and brown carbon. Black carbon (BC; also referred to as light-absorbing carbon [LAC], refractory black carbon [rBC], and soot) is second only to CO2 as a positive forcing agent. Roughly 60% of BC emissions can be attributed to anthropogenic sources (fossil fuel combustion and open-pit cooking), with the remaining fraction being due to biomass burning. Brown carbon (BrC), a major component of biomass burning, collectively refers to non-BC carbonaceous aerosols that typically possess minimal light absorption at visible wavelengths but exhibit pronounced light absorption in the near-ultraviolet (UV) spectrum. Both species can be sourced locally or be remotely transported to the Arctic region and are expected to perturb the radiative balance. The work conducted in this field campaign addresses one of the more glaring deficiencies currently limiting improved quantification of the impact of BC radiative forcing in the cryosphere: the paucity of data on the vertical and spatial distributions of BC. By expanding the Gulfstream aircraft (G-1) payload for the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility-sponsored ACME-V campaign to include the Single-Particle Soot Photometer (SP2)) and leveraging the ACME-V campaign’s deployment within the Arctic Circle during the summer of 2015 (Deadhorse, Alaska [70° 12' 20" N, 148° 30' 42" W]), the truly unique opportunity presented itself to acquire profile data on BC loading at little additional cost. Since the SP2 is a particle-resolved measurement, the resulting data set provides refractory black carbon (rBC) mass loadings, size and mass distributions, and rBC-containing particle mixing state, all of which are expected to readily find value in the modeling community. As part of the ACME-V (http://www.arm.gov/campaigns/aaf2014armacmev) campaign, CO, CO2, and CH4 were also measured, providing the unique opportunity for carbon closure. We will also work closely with modelers who require such data and expect this collaboration will lead directly to a better understanding of the climate impacts of BC in the Arctic. The primary measurement objective was to acquire airborne data on the vertical and spatial distributions of refractory black carbon (rBC) loading, size and mass distribution, and particle mixing state. The primary scientific objective was to provide a targeted data set of rBC particle distributions to better understand and constrain the impact of black carbon radiative forcing in the cryosphere. The SP2-based data set during this campaign is available in the DOE-ARM archive (http://www.arm.gov/campaigns/aaf2015abclp).« less

Parsivel Disdrometer Support for MAGIC Field Campaign Report

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

Kollias, Pavlos; Bartholomew, Mary Jane

2016-06-01

In the Marine ARM GPCI Investigation of Clouds (MAGIC) field campaign, the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s second Mobile Facility (AMF2) was deployed on the Horizon Lines cargo ship Spirit traversing a route between Los Angeles, California and Honolulu, Hawaii for one full year. The transect for this deployment was chosen specifically because it crosses the stratocumulus-to-cumulus transition of the North-East Pacific, a region of great climatic interest and a close approximation to the transect used for several focused model intercomparison efforts. The cloud type and cover along this transect vary from lowmore » marine stratocumulus with high areal coverage near the California coast to isolated shallow cumulus with much lower areal coverage in the trade wind regime near Hawaii. The low marine stratocumulus decks, with their high albedo, exert a major influence on the shortwave radiation budget in the ocean environment, and thus provide an extremely important forcing of Earth’s climate. The trade cumulus clouds play a large role in the global surface evaporation and also in Earth’s albedo. One of the important science drivers of the MAGIC campaign was to measure the properties of clouds and precipitation, specifically cloud type, fractional coverage, base height, physical thickness, liquid water path (LWP), optical depth, and drizzle and precipitation frequency, amount, and extent. Retrievals of cloud and precipitation properties during the MAGIC campaign relied critically on the calibration of the AMF2 radar systems. For MAGIC this included the KAZR and M-WACR, both fixed zenith-pointing systems, and the 1290 MHz beam steerable wind profiler.« less

A Unified Approach for Reporting ARM Measurement Uncertainties Technical Report: Updated in 2016

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

Sisterson, Douglas

The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility is observationally based, and quantifying the uncertainty of its measurements is critically important. With over 300 widely differing instruments providing over 2,500 datastreams, concise expression of measurement uncertainty is quite challenging. ARM currently provides data and supporting metadata (information about the data or data quality) to its users through several sources. Because the continued success of the ARM Facility depends on the known quality of its measurements, ARM relies on Instrument Mentors and the ARM Data Quality Office to ensure, assess, and report measurement quality. Therefore, anmore » easily accessible, well-articulated estimate of ARM measurement uncertainty is needed. This report is a continuation of the work presented by Campos and Sisterson (2015) and provides additional uncertainty information from instruments not available in their report. As before, a total measurement uncertainty has been calculated as a function of the instrument uncertainty (calibration factors), the field uncertainty (environmental factors), and the retrieval uncertainty (algorithm factors). This study will not expand on methods for computing these uncertainties. As before, it will focus on the practical identification, characterization, and inventory of the measurement uncertainties already available to the ARM community through the ARM Instrument Mentors and their ARM instrument handbooks. This study continues the first steps towards reporting ARM measurement uncertainty as: (1) identifying how the uncertainty of individual ARM measurements is currently expressed, (2) identifying a consistent approach to measurement uncertainty, and then (3) reclassifying ARM instrument measurement uncertainties in a common framework.« less

A parametric model of muscle moment arm as a function of joint angle: application to the dorsiflexor muscle group in mice.

PubMed

Miller, S W; Dennis, R G

1996-12-01

A parametric model was developed to describe the relationship between muscle moment arm and joint angle. The model was applied to the dorsiflexor muscle group in mice, for which the moment arm was determined as a function of ankle angle. The moment arm was calculated from the torque measured about the ankle upon application of a known force along the line of action of the dorsiflexor muscle group. The dependence of the dorsiflexor moment arm on ankle angle was modeled as r = R sin(a + delta), where r is the moment arm calculated from the measured torque and a is the joint angle. A least-squares curve fit yielded values for R, the maximum moment arm, and delta, the angle at which the maximum moment arm occurs as offset from 90 degrees. Parametric models were developed for two strains of mice, and no differences were found between the moment arms determined for each strain. Values for the maximum moment arm, R, for the two different strains were 0.99 and 1.14 mm, in agreement with the limited data available from the literature. While in some cases moment arm data may be better fitted by a polynomial, use of the parametric model provides a moment arm relationship with meaningful anatomical constants, allowing for the direct comparison of moment arm characteristics between different strains and species.

The diurnal cycle of clouds and precipitation at the ARM SGP site: Cloud radar observations and simulations from the multiscale modeling framework

DOE PAGES

Zhao, Wei; Marchand, Roger; Fu, Qiang

2017-07-08

Millimeter Wavelength Cloud Radar (MMCR) data from December 1996 to December 2010, collected at the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) program Southern Great Plains (SGP) site, are used to examine the diurnal cycle of hydrometeor occurrence. These data are categorized into clouds (-40 dBZ e ≤ reflectivity < -10 dBZ e), drizzle and light precipitation (-10 dBZ e ≤ reflectivity < 10 dBZ e), and heavy precipitation (reflectivity ≥ 10 dBZ e). The same criteria are implemented for the observation-equivalent reflectivity calculated by feeding outputs from a Multiscale Modeling Framework (MMF) climate model into a radar simulator.more » The MMF model consists of the National Center for Atmospheric Research Community Atmosphere Model with conventional cloud parameterizations replaced by a cloud-resolving model. We find that a radar simulator combined with the simple reflectivity categories can be an effective approach for evaluating diurnal variations in model hydrometeor occurrence. It is shown that the MMF only marginally captures observed increases in the occurrence of boundary layer clouds after sunrise in spring and autumn and does not capture diurnal changes in boundary layer clouds during the summer. Above the boundary layer, the MMF captures reasonably well diurnal variations in the vertical structure of clouds and light and heavy precipitation in the summer but not in the spring.« less

Final Report: "Collaborative Project. Understanding the Chemical Processes That Affect Growth Rates of Freshly Nucleated Particles"

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

Smith, James N.; McMurry, Peter H.

This final technical report describes our research activities that have, as the ultimate goal, the development of a model that explains growth rates of freshly nucleated particles. The research activities, which combine field observations with laboratory experiments, explore the relationship between concentrations of gas-phase species that contribute to growth and the rates at which those species are taken up. We also describe measurements of the chemical composition of freshly nucleated particles in a variety of locales, as well as properties (especially hygroscopicity) that influence their effects on climate. Our measurements include a self-organized, DOE-ARM funded project at the Southern Greatmore » Plains site, the New Particle Formation Study (NPFS), which took place during spring 2013. NPFS data are available to the research community on the ARM data archive, providing a unique suite observations of trace gas and aerosols that are associated with the formation and growth of atmospheric aerosol particles.« less

Sources, Composition, and Properties of Newly Formed and Regional Organic Aerosol in a Boreal Forest during the Biogenic Aerosol: Effects on Clouds and Climate Field Campaign Report

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

Thornton, Joel

2016-05-01

The Thornton Laboratory participated in the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s Biogenic Aerosol Effects on Clouds and Climate (BAECC) campaign in Finland by deploying our mass spectrometer. We then participated in environmental simulation chamber studies at Pacific Northwest National Laboratory (PNNL). Thereafter, we analyzed the results as demonstrated in the several presentations and publications. The field campaign and initial environmental chamber studies are described below.

Evaluating cloud retrieval algorithms with the ARM BBHRP framework

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

Mlawer,E.; Dunn,M.; Mlawer, E.

2008-03-10

Climate and weather prediction models require accurate calculations of vertical profiles of radiative heating. Although heating rate calculations cannot be directly validated due to the lack of corresponding observations, surface and top-of-atmosphere measurements can indirectly establish the quality of computed heating rates through validation of the calculated irradiances at the atmospheric boundaries. The ARM Broadband Heating Rate Profile (BBHRP) project, a collaboration of all the working groups in the program, was designed with these heating rate validations as a key objective. Given the large dependence of radiative heating rates on cloud properties, a critical component of BBHRP radiative closure analysesmore » has been the evaluation of cloud microphysical retrieval algorithms. This evaluation is an important step in establishing the necessary confidence in the continuous profiles of computed radiative heating rates produced by BBHRP at the ARM Climate Research Facility (ACRF) sites that are needed for modeling studies. This poster details the continued effort to evaluate cloud property retrieval algorithms within the BBHRP framework, a key focus of the project this year. A requirement for the computation of accurate heating rate profiles is a robust cloud microphysical product that captures the occurrence, height, and phase of clouds above each ACRF site. Various approaches to retrieve the microphysical properties of liquid, ice, and mixed-phase clouds have been processed in BBHRP for the ACRF Southern Great Plains (SGP) and the North Slope of Alaska (NSA) sites. These retrieval methods span a range of assumptions concerning the parameterization of cloud location, particle density, size, shape, and involve different measurement sources. We will present the radiative closure results from several different retrieval approaches for the SGP site, including those from Microbase, the current 'reference' retrieval approach in BBHRP. At the NSA, mixed-phase clouds and cloud with a low optical depth are prevalent; the radiative closure studies using Microbase demonstrated significant residuals. As an alternative to Microbase at NSA, the Shupe-Turner cloud property retrieval algorithm, aimed at improving the partitioning of cloud phase and incorporating more constrained, conditional microphysics retrievals, also has been evaluated using the BBHRP data set.« less

Advancing cloud lifecycle representation in numerical models using innovative analysis methods that bridge arm observations over a breadth of scales

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

Tselioudis, George

2016-03-04

From its location on the subtropics-midlatitude boundary, the Azores is influenced by both the subtropical high pressure and the midlatitude baroclinic storm regimes, and therefore experiences a wide range of cloud structures, from fair-weather scenes to stratocumulus sheets to deep convective systems. This project combined three types of data sets to study cloud variability in the Azores: a satellite analysis of cloud regimes, a reanalysis characterization of storminess, and a 19-month field campaign that occurred on Graciosa Island. Combined analysis of the three data sets provides a detailed picture of cloud variability and the respective dynamic influences, with emphasis onmore » low clouds that constitute a major uncertainty source in climate model simulations. The satellite cloud regime analysis shows that the Azores cloud distribution is similar to the mean global distribution and can therefore be used to evaluate cloud simulation in global models. Regime analysis of low clouds shows that stratocumulus decks occur under the influence of the Azores high-pressure system, while shallow cumulus clouds are sustained by cold-air outbreaks, as revealed by their preference for post-frontal environments and northwesterly flows. An evaluation of CMIP5 climate model cloud regimes over the Azores shows that all models severely underpredict shallow cumulus clouds, while most models also underpredict the occurrence of stratocumulus cloud decks. It is demonstrated that carefully selected case studies can be related through regime analysis to climatological cloud distributions, and a methodology is suggested utilizing process-resolving model simulations of individual cases to better understand cloud-dynamics interactions and attempt to explain and correct climate model cloud deficiencies.« less

Islands Climatology at Local Scale. Downscaling with CIELO model

NASA Astrophysics Data System (ADS)

Azevedo, Eduardo; Reis, Francisco; Tomé, Ricardo; Rodrigues, Conceição

2016-04-01

Islands with horizontal scales of the order of tens of km, as is the case of the Atlantic Islands of Macaronesia, are subscale orographic features for Global Climate Models (GCMs) since the horizontal scales of these models are too coarse to give a detailed representation of the islands' topography. Even the Regional Climate Models (RCMs) reveals limitations when they are forced to reproduce the climate of small islands mainly by the way they flat and lowers the elevation of the islands, reducing the capacity of the model to reproduce important local mechanisms that lead to a very deep local climate differentiation. Important local thermodynamics mechanisms like Foehn effect, or the influence of topography on radiation balance, have a prominent role in the climatic spatial differentiation. Advective transport of air - and the consequent induced adiabatic cooling due to orography - lead to transformations of the state parameters of the air that leads to the spatial configuration of the fields of pressure, temperature and humidity. The same mechanism is in the origin of the orographic clouds cover that, besides the direct role as water source by the reinforcement of precipitation, act like a filter to direct solar radiation and as a source of long-wave radiation that affect the local balance of energy. Also, the saturation (or near saturation) conditions that they provide constitute a barrier to water vapour diffusion in the mechanisms of evapotranspiration. Topographic factors like slope, aspect and orographic mask have also significant importance in the local energy balance. Therefore, the simulation of the local scale climate (past, present and future) in these archipelagos requires the use of downscaling techniques to adjust locally outputs obtained at upper scales. This presentation will discuss and analyse the evolution of the CIELO model (acronym for Clima Insular à Escala LOcal) a statistical/dynamical technique developed at the University of the Azores, which has been improved since its original version, constituting currently a downscaling tool widely applied with success in different islands of Macaronesia. Recently the CIELO model has been tested against data from the Eastern North Atlantic (ENA), Graciosa Island ARM facility programme (established and supported by the U.S. Department of Energy with the collaboration of the local government and the University of the Azores).

Autonomous, Full-Time Cloud Profiling at Arm Sites with Micro Pulse Lidar

NASA Technical Reports Server (NTRS)

Spinhirne, James D.; Campbell, James R.; Hlavka, Dennis L.; Scott, V. Stanley; Flynn, Connor J.

2000-01-01

Since the early 1990's technology advances permit ground based lidar to operate full time and profile all significant aerosol and cloud structure of the atmosphere up to the limit of signal attenuation. These systems are known as Micro Pulse Lidars (MPL), as referenced by Spinhirne (1993), and were first in operation at DOE Atmospheric Radiation Measurement (ARM) sites. The objective of the ARM program is to improve the predictability of climate change, particularly as it relates to cloud-climate feedback. The fundamental application of the MPL systems is towards the detection of all significant hydrometeor layers, to the limit of signal attenuation. The heating and cooling of the atmosphere are effected by the distribution and characteristics of clouds and aerosol concentration. Aerosol and cloud retrievals in several important areas can only be adequately obtained with active remote sensing by lidar. For cloud cover, the height and related emissivity of thin clouds and the distribution of base height for all clouds are basic parameters for the surface radiation budget, and lidar is essetial for accurate measurements. The ARM MPL observing network represents the first long-term, global lidar study known within the community. MPL systems are now operational at four ARM sites. A six year data set has been obtained at the original Oklahoma site, and there are several years of observations at tropical and artic sites. Observational results include cloud base height distributions and aerosol profiles. These expanding data sets offer a significant new resource for cloud, aerosol and atmospheric radiation analysis. The nature of the data sets, data processing algorithms, derived parameters and application results are presented.

C-arm rotation encoding with accelerometers.

PubMed

Grzeda, Victor; Fichtinger, Gabor

2010-07-01

Fluoroscopic C-arms are being incorporated in computer-assisted interventions in increasing number. For these applications to work, the relative poses of imaging must be known. To find the pose, tracking methods such as optical cameras, electromagnetic trackers, and radiographic fiducials have been used-all hampered by significant shortcomings. We propose to recover the rotational pose of the C-arm using the angle-sensing ability of accelerometers, by exploiting the capability of the accelerometer to measure tilt angles. By affixing the accelerometer to a C-arm, the accelerometer tracks the C-arm pose during rotations of the C-arm. To demonstrate this concept, a C-arm analogue was constructed with a webcam device affixed to the C-arm model to mimic X-ray imaging. Then, measuring the offset between the accelerometer angle readings to the webcam pose angle, an angle correction equation (ACE) was created to properly tracking the C-arm rotational pose. Several tests were performed on the webcam C-arm model using the ACEs to tracking the primary and secondary angle rotations of the model. We evaluated the capability of linear and polynomial ACEs to tracking the webcam C-arm pose angle for different rotational scenarios. The test results showed that the accelerometer could track the pose of the webcam C-arm model with an accuracy of less than 1.0 degree. The accelerometer was successful in sensing the C-arm's rotation with clinically adequate accuracy in the C-arm webcam model.

AMS Professional Development Courses: Arming K-12 Teachers with the Tools Needed to Increase Students' Scientific Literacy

NASA Astrophysics Data System (ADS)

Brey, J. A.; Geer, I. W.; Weinbeck, R. S.; Moran, J. M.; Nugnes, K. A.

2012-12-01

To better prepare tomorrow's leaders, it is of utmost importance that today's teachers are science literate. To meet that need, the American Meteorological Society (AMS) Education Program offers content-rich, professional development courses and training workshops for precollege teachers in the geosciences. During the fall and spring semesters, the AMS in partnership with NOAA, NASA, and SUNY Brockport, offers a suite of pre-college teacher development courses, DataStreme Atmosphere, DataStreme Ocean and DataStreme Earth's Climate System (ECS). These courses are delivered to small groups of K-12 teachers through Local Implementation Teams (LITs) positioned throughout the U.S. The courses use current, real-world environmental data to investigate the atmosphere, ocean, and climate system and consist of weekly online study materials, weekly mentoring, and several face-to-face meetings, all supplemented by a provided textbook and investigations manual. DataStreme ECS takes an innovative approach to studying climate science, by exploring the fundamental science of Earth's climate system and addressing the societal impacts relevant to today's students and teachers. The course investigates natural and human forcings and feedbacks to examine mitigation and adaptation strategies for the future. Information and data from respected organizations, such as the IPCC, the US Global Change Research Program, NASA, and NOAA are used throughout the course, including in the online and printed investigations. In addition, participants differentiate between climate, climate variability, and climate change through the AMS Conceptual Energy Model, a basic climate model that follows the flow of energy from space to Earth and back. Participants also have access to NASA's EdGCM, a research-grade Global Climate Model where they can explore various future climate scenarios in the same way that actual research scientists do. Throughout all of the courses, teachers have the opportunity to expand their knowledge in the geosciences and incorporate technology into their classrooms by utilizing state-of-the-art resources from NOAA, NASA, and other lead scientific organizations. Upon completion of each course, teachers receive three free graduate credits from SUNY Brockport. The DataStreme courses have directly trained almost 17,000 teachers, impacting over one million students. The DataStreme courses have increased teachers' geoscience knowledge, pointing them to the resources available online, and building their confidence in understanding dynamic Earth systems. Through courses modeled on scientific inquiry and fashioned to develop critical thinking skills, these teachers become a resource for their classrooms and colleagues.

Evaluation of cloud-resolving model simulations of midlatitude cirrus with ARM and A-train observations

DOE PAGES

Muhlbauer, A.; Ackerman, T. P.; Lawson, R. P.; ...

2015-07-14

Cirrus clouds are ubiquitous in the upper troposphere and still constitute one of the largest uncertainties in climate predictions. Our paper evaluates cloud-resolving model (CRM) and cloud system-resolving model (CSRM) simulations of a midlatitude cirrus case with comprehensive observations collected under the auspices of the Atmospheric Radiation Measurements (ARM) program and with spaceborne observations from the National Aeronautics and Space Administration A-train satellites. The CRM simulations are driven with periodic boundary conditions and ARM forcing data, whereas the CSRM simulations are driven by the ERA-Interim product. Vertical profiles of temperature, relative humidity, and wind speeds are reasonably well simulated bymore » the CSRM and CRM, but there are remaining biases in the temperature, wind speeds, and relative humidity, which can be mitigated through nudging the model simulations toward the observed radiosonde profiles. Simulated vertical velocities are underestimated in all simulations except in the CRM simulations with grid spacings of 500 m or finer, which suggests that turbulent vertical air motions in cirrus clouds need to be parameterized in general circulation models and in CSRM simulations with horizontal grid spacings on the order of 1 km. The simulated ice water content and ice number concentrations agree with the observations in the CSRM but are underestimated in the CRM simulations. The underestimation of ice number concentrations is consistent with the overestimation of radar reflectivity in the CRM simulations and suggests that the model produces too many large ice particles especially toward the cloud base. Simulated cloud profiles are rather insensitive to perturbations in the initial conditions or the dimensionality of the model domain, but the treatment of the forcing data has a considerable effect on the outcome of the model simulations. Despite considerable progress in observations and microphysical parameterizations, simulating the microphysical, macrophysical, and radiative properties of cirrus remains challenging. Comparing model simulations with observations from multiple instruments and observational platforms is important for revealing model deficiencies and for providing rigorous benchmarks. But, there still is considerable need for reducing observational uncertainties and providing better observations especially for relative humidity and for the size distribution and chemical composition of aerosols in the upper troposphere.« less

Job-Oriented Basic Skills (JOBS) Program: Administrator’s Guide.

DTIC Science & Technology

1981-02-01

direction systems, in a clean, corn- target designation fortable shop-like systems, and electro- environment. FT. hydr- aulic fire con- usually work...situations, all types of guninery clean or dirty work, equipment from dadh or shop, and missiles to small any kind of climate arms. or temperature. They...string Their duties may wires, and install be carried out in transformers and tropical or arctic distribution panels, climates in many different work 3

Aerosol-Cloud Interactions in the South-East Atlantic: Knowledge Gaps, Planned Observations to Address Them, and Implications for Global Climate Change Modeling

NASA Technical Reports Server (NTRS)

Redemann, Jens; Wood, R.; Zuidema, P.; Haywood, J.; Luna, B.; Abel, S.

2015-01-01

Southern Africa produces almost a third of the Earth's biomass burning (BB) aerosol particles, yet the fate of these particles and their influence on regional and global climate is poorly understood. Particles lofted into the mid-troposphere are transported westward over the South-East (SE) Atlantic, home to one of the three permanent subtropical Stratocumulus (Sc) cloud decks in the world. The stratocumulus "climate radiators" are critical to the regional and global climate system. They interact with dense layers of BB aerosols that initially overlay the cloud deck, but later subside and are mixed into the clouds. These interactions include adjustments to aerosol-induced solar heating and microphysical effects. As emphasized in the latest IPCC report, the global representation of these aerosol-cloud interaction processes in climate models is one of the largest uncertainty in estimates of future climate. Hence, new observations over the SE Atlantic have significant implications for global climate change scenarios. We discuss the current knowledge of aerosol and cloud property distributions based on satellite observations and sparse suborbital sampling, and describe planned field campaigns in the region. Specifically, we describe the scientific objectives and implementation of the following four synergistic, international research activities aimed at providing a process-level understanding of aerosol-cloud interactions over the SE Atlantic: 1) ORACLES (Observations of Aerosols above Clouds and their interactions), a five-year investigation between 2015 and 2019 with three Intensive Observation Periods (IOP), recently funded by the NASA Earth-Venture Suborbital Program, 2) CLARIFY-2016 (Cloud-Aerosol-Radiation Interactions and Forcing: Year 2016), a comprehensive observational and modeling programme funded by the UK's Natural Environment Research Council (NERC), and supported by the UK Met Office. 3) LASIC (Layered Atlantic Smoke Interactions with Clouds), a funded deployment of the DOE (Department of Energy) ARM Mobile Facility (AMF1) to Ascension Island, nominally for April 1 2016 - March 31 2017, and 4) ONFIRE (Observations of Fire's Impact on the southeast Atlantic Region), a proposed deployment of the NCAR C-130 aircraft to Sao Tome Island in 2017.

On the Onset of the Rainy Season in Amazonia: WHAT the Observations Show, and Why the Biases in Climate Models?

NASA Astrophysics Data System (ADS)

Marengo, J. A.; Alves, L. M.; Fu, R.

2014-12-01

The onset of the Amazon rainy season shows a large temporal and spatial variability, delays on the date of the onset will have strong impacts on local agriculture, hydroelectric power generation as well as on the hydrology of large rivers. Two "once-in-a-century" droughts occurred in 2005 and 2010, and it was shown that in those events the rainy season started later than normal, and also that on the last 10 years the dry season has increased in length by about one month. These events highlight the urgency for improving our understanding and capability to model onset of the rainy season and drought variability, for the present and future. Most studies have attributed the variability of the rainy season onset over Amazonia to the variability of the tropical oceans whether other factors, such as climate change, land use and aerosols also contribute to the variability are not clear.. Global climate models run on seasonal climate forecast mode still show large uncertainties on the prediction of onset of seasonal rains. As for climate change, the CMIP3 and CMIP5 appear to underestimate the past variability, and also project virtually no future change of the onset of rainy season over the Amazon even when they are forced by strong greenhouse forcing under the RCP8.5 emission scenario. Why these models underestimate the variability of the rainy season onset, and whether this bias implies an underestimate of sensitivity of their dry season length to anthropogenic radiative forcing remain unclear. This FAPESP DOE grant 2013/50538 aims to explore use of the measurements provided by the Atmospheric Radiation Measurement (ARM) Mobile Facilities (AMF)-GoAmazon and the Cloud processes of the main precipitation systems in Brazil (CHUVA) Field Experiments, along with global and regional model experiments, to explore the sources of the above described uncertainty. The project will address several issues, i.e. the inadequate representation of the types of convection (i.e., maritime versus continental) and their relationships to aerosols, land surface and atmospheric circulation as represented in climate models We will present our initial results addressing the factors that control the variability of the wet season onset over Amazonia, the influence of convective types on atmospheric diabatic heating based on GoAmazon and CHUVA.

C-Band Scanning ARM Precipitation Radar (C-SAPR) Handbook

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

Widener, K; Bharadwaj, N

2012-11-13

The C-band scanning ARM precipitation radar (C-SAPR) is a scanning polarimetric Doppler radar transmitting simultaneously in both H and V polarizations. With a 350-kW magnetron transmitter, this puts 125 kW of transmitted power for each polarization. The receiver for the C-SAPR is a National Center for Atmospheric Research (NCAR) -developed Hi-Q system operating in a coherent-on-receive mode. The ARM Climate Research Facility operates two C-SAPRs; one of them is deployed near the Southern Great Plains (SGP) Central Facility near the triangular array of X-SAPRs, and the second C-SAPR is deployed at ARM’s Tropical Western Pacific (TWP) site on Manus Islandmore » in Papua New Guinea.« less

Aeroelastic instability stoppers for wind tunnel models

NASA Technical Reports Server (NTRS)

Doggett, R. V., Jr.; Ricketts, R. H. (Inventor)

1981-01-01

A mechanism for constraining models or sections thereof, was wind tunnel tested, deployed at the onset of aeroelastic instability, to forestall destructive vibrations in the model is described. The mechanism includes a pair of arms pivoted to the tunnel wall and straddling the model. Rollers on the ends of the arms contact the model, and are pulled together against the model by a spring stretched between the arms. An actuator mechanism swings the arms into place and back as desired.

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

Jardine, Kolby

In conjunction with the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility GoAmazon campaign, the Terrestrial Ecosystem Science (TES)-funded Green Ocean Amazon (GoAmazon 2014/15) terrestrial ecosystem project (Geco) was designed to: • evaluate the strengths and weaknesses of leaf-level algorithms for biogenic volatile organic compounds (BVOCs) emissions in Amazon forests near Manaus, Brazil, and • conduct mechanistic field studies to characterize biochemical and physiological processes governing leaf- and landscape-scale tropical forest BVOC emissions, and the influence of environmental drivers that are expected to change with a warming climate. Through a close interaction between modeling and observationalmore » activities, including the training of MS and PhD graduate students, post-doctoral students, and technicians at the National Institute for Amazon Research (INPA), the study aimed at improving the representation of BVOC-mediated biosphere-atmosphere interactions and feedbacks under a warming climate. BVOCs can form cloud condensation nuclei (CCN) that influence precipitation dynamics and modify the quality of down welling radiation for photosynthesis. However, our ability to represent these coupled biosphere-atmosphere processes in Earth system models suffers from poor understanding of the functions, identities, quantities, and seasonal patterns of BVOC emissions from tropical forests as well as their biological and environmental controls. The Model of Emissions of Gases and Aerosols from Nature (MEGAN), the current BVOC sub-model of the Community Earth System Model (CESM), was evaluated to explore mechanistic controls over BVOC emissions. Based on that analysis, a combination of observations and experiments were studied in forests near Manaus, Brazil, to test existing parameterizations and algorithm structures in MEGAN. The model was actively modified as needed to improve tropical BVOC emission simulations on a regional scale.« less

ARM West Antarctic Radiation Experiment (AWARE) Field Campaign Report

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

Lubin, Daniel; Bromwich, David H; Vogelmann, Andrew M

The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) West Antarctic Radiation Experiment (AWARE) is the most technologically advanced atmospheric and climate science campaign yet fielded in Antarctica. AWARE was motivated be recent concern about the impact of cryospheric mass loss on global sea level rise. Specifically, the West Antarctic Ice Sheet (WAIS) is now the second largest contributor to rising sea level, after the Greenland Ice Sheet. As steadily warming ocean water erodes the grounding lines of WAIS components where they meet the Amundsen and Bellingshausen Seas, the retreating grounding lines moving inland and downslope on the underlyingmore » terrain imply mechanical instability of the entire WAIS. There is evidence that this point of instability may have already been reached, perhaps signifying more rapid loss of WAIS ice mass. At the same time, the mechanical support provided by adjacent ice shelves, and also the fundamental stability of exposed ice cliffs at the ice sheet grounding lines, will be adversely impacted by a warming atmosphere that causes more frequent episodes of surface melting. The surface meltwater damages the ice shelves and ice cliffs through hydrofracturing. With the increasing concern regarding these rapid cryospheric changes, AWARE was motivated by the need to (a) diagnose the surface energy balance in West Antarctica as related to both summer season climatology and potential surface melting, and (b) improve global climate model (GCM) performance over Antarctica, such that future cryospheric projections can be more reliable.« less

Aerosol Inlet Characterization Experiment Report

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

Bullard, Robert L.; Kuang, Chongai; Uin, Janek

2017-05-01

The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility Aerosol Observation System inlet stack was characterized for particle penetration efficiency from 10 nm to 20 μm in diameter using duplicate scanning mobility particle sizers (10 nm-450 nm), ultra-high-sensitivity aerosol spectrometers (60 nm-μm), and aerodynamic particle sizers (0.5 μm-20 μm). Results show good model-measurement agreement and unit transmission efficiency of aerosols from 10 nm to 4 μm in diameter. Large uncertainties in the measured transmission efficiency exist above 4 μm due to low ambient aerosol signal in that size range.

Numerical simulation of geomorphic, climatic and anthropogenic drivers of soil distribution on semi-arid hillslopes

NASA Astrophysics Data System (ADS)

Willgoose, G. R.; Cohen, S.; Svoray, T.; Sela, S.; Hancock, G. R.

2010-12-01

Numerical models are an important tool for studying landscape processes as they allow us to isolate specific processes and drivers and test various physics and spatio-temporal scenarios. Here we use a distributed physically-based soil evolution model (mARM4D) to describe the drivers and processes controlling soil-landscape evolution on a field-site at the fringe between the Mediterranean and desert regions of Israel. This study is an initial effort in a larger project aimed at improving our understanding of the mechanisms and drivers that led to the extensive removal of soils from the loess covered hillslopes of this region. This specific region is interesting as it is located between the Mediterranean climate region in which widespread erosion from hillslopes was attributed to human activity during the Holocene and the arid region in which extensive removal of loess from hillslopes was shown to have been driven by climatic changes during the late-Pleistocene. First we study the sediment transport mechanism of the soil-landscape evolution processes in our study-site. We simulate soil-landscape evolution with only one sediment transport process (fluvial or diffusive) at a time. We find that diffusive sediment transport is likely the dominant process in this site as it resulted in soil distributions that better corresponds to current observations. We then simulate several realistic climatic/anthropogenic scenarios (based on the literature) in order to quantify the sensitivity of the soil-landscape evolution process to temporal fluctuations. We find that this site is relatively insensitive to short term (several thousands of years) sharp, changes. This suggests that climate, rather then human activity, was the main driver for the extensive removal of loess from the hillslopes.

SpaceCubeX: A Framework for Evaluating Hybrid Multi-Core CPU FPGA DSP Architectures

NASA Technical Reports Server (NTRS)

Schmidt, Andrew G.; Weisz, Gabriel; French, Matthew; Flatley, Thomas; Villalpando, Carlos Y.

2017-01-01

The SpaceCubeX project is motivated by the need for high performance, modular, and scalable on-board processing to help scientists answer critical 21st century questions about global climate change, air quality, ocean health, and ecosystem dynamics, while adding new capabilities such as low-latency data products for extreme event warnings. These goals translate into on-board processing throughput requirements that are on the order of 100-1,000 more than those of previous Earth Science missions for standard processing, compression, storage, and downlink operations. To study possible future architectures to achieve these performance requirements, the SpaceCubeX project provides an evolvable testbed and framework that enables a focused design space exploration of candidate hybrid CPU/FPGA/DSP processing architectures. The framework includes ArchGen, an architecture generator tool populated with candidate architecture components, performance models, and IP cores, that allows an end user to specify the type, number, and connectivity of a hybrid architecture. The framework requires minimal extensions to integrate new processors, such as the anticipated High Performance Spaceflight Computer (HPSC), reducing time to initiate benchmarking by months. To evaluate the framework, we leverage a wide suite of high performance embedded computing benchmarks and Earth science scenarios to ensure robust architecture characterization. We report on our projects Year 1 efforts and demonstrate the capabilities across four simulation testbed models, a baseline SpaceCube 2.0 system, a dual ARM A9 processor system, a hybrid quad ARM A53 and FPGA system, and a hybrid quad ARM A53 and DSP system.

USGCRP assessments: Meeting the challenges of climate and global change

NASA Astrophysics Data System (ADS)

Dickinson, T.; Kuperberg, J. M.

2016-12-01

The United States Global Change Research Program (USGCRP) is a confederation of the research arms of 13 Federal departments and agencies. Its mission is to build a knowledge base that informs human responses to climate and global change through coordinated and integrated Federal programs of research, education, communication, and decision support. USGCRP has supported several initiatives to promote better understanding of climate change impacts on health, support responses, and build on the progress of the 2014 National Climate Assessment. Most recently, USGCRP released a new report, "The Impacts of Climate Change on Human Health: A Scientific Assessment". This presentation will provide an overview of USGCRP, highlight the importance of assessments, and introduce ways in which assessment findings and underlying data can be translated into critical tools to build resilience.

Generating Variable Wind Profiles and Modeling Their Effects on Small-Arms Trajectories

DTIC Science & Technology

2016-04-01

ARL-TR-7642 ● APR 2016 US Army Research Laboratory Generating Variable Wind Profiles and Modeling Their Effects on Small-Arms... Wind Profiles and Modeling Their Effects on Small-Arms Trajectories by Timothy A Fargus Weapons and Materials Research Directorate, ARL...Generating Variable Wind Profiles and Modeling Their Effects on Small-Arms Trajectories 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM

ARM Airborne Carbon Measurements VI (ACME VI) Science Plan

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

Biraud, S

2015-12-01

From October 1 through September 30, 2016, the Atmospheric Radiation Measurement (ARM) Aerial Facility will deploy the Cessna 206 aircraft over the Southern Great Plains (SGP) site, collecting observations of trace-gas mixing ratios over the ARM’s SGP facility. The aircraft payload includes two Atmospheric Observing Systems, Inc., analyzers for continuous measurements of CO2 and a 12-flask sampler for analysis of carbon cycle gases (CO2, CO, CH4, N2O, 13CO2, 14CO2, carbonyl sulfide, and trace hydrocarbon species, including ethane). The aircraft payload also includes instrumentation for solar/infrared radiation measurements. This research is supported by the U.S. Department of Energy’s ARM Climate Researchmore » Facility and Terrestrial Ecosystem Science Program and builds upon previous ARM Airborne Carbon Measurements (ARM-ACME) missions. The goal of these measurements is to improve understanding of 1) the carbon exchange at the SGP site, 2) how CO2 and associated water and energy fluxes influence radiative forcing, convective processes and CO2 concentrations over the SGP site, and 3) how greenhouse gases are transported on continental scales.« less

9 CFR 318.10 - Prescribed treatment of pork and products containing pork to destroy trichinae.

Code of Federal Regulations, 2012 CFR

2012-01-01

... distribution in tropical climates or smoked hams delivered to the Armed Services); ground meat mixtures... water may be changed once, but they shall not be subjected to any other treatment designed to remove...

9 CFR 318.10 - Prescribed treatment of pork and products containing pork to destroy trichinae.

Code of Federal Regulations, 2011 CFR

2011-01-01

... distribution in tropical climates or smoked hams delivered to the Armed Services); ground meat mixtures... water may be changed once, but they shall not be subjected to any other treatment designed to remove...

9 CFR 318.10 - Prescribed treatment of pork and products containing pork to destroy trichinae.

Code of Federal Regulations, 2014 CFR

2014-01-01

... distribution in tropical climates or smoked hams delivered to the Armed Services); ground meat mixtures... water may be changed once, but they shall not be subjected to any other treatment designed to remove...

CAUSES: Diagnosis of the Summertime Warm Bias in CMIP5 Climate Models at the ARM Southern Great Plains Site

NASA Astrophysics Data System (ADS)

Zhang, Chengzhu; Xie, Shaocheng; Klein, Stephen A.; Ma, Hsi-yen; Tang, Shuaiqi; Van Weverberg, Kwinten; Morcrette, Cyril J.; Petch, Jon

2018-03-01

All the weather and climate models participating in the Clouds Above the United States and Errors at the Surface project show a summertime surface air temperature (T2 m) warm bias in the region of the central United States. To understand the warm bias in long-term climate simulations, we assess the Atmospheric Model Intercomparison Project simulations from the Coupled Model Intercomparison Project Phase 5, with long-term observations mainly from the Atmospheric Radiation Measurement program Southern Great Plains site. Quantities related to the surface energy and water budget, and large-scale circulation are analyzed to identify possible factors and plausible links involved in the warm bias. The systematic warm season bias is characterized by an overestimation of T2 m and underestimation of surface humidity, precipitation, and precipitable water. Accompanying the warm bias is an overestimation of absorbed solar radiation at the surface, which is due to a combination of insufficient cloud reflection and clear-sky shortwave absorption by water vapor and an underestimation in surface albedo. The bias in cloud is shown to contribute most to the radiation bias. The surface layer soil moisture impacts T2 m through its control on evaporative fraction. The error in evaporative fraction is another important contributor to T2 m. Similar sources of error are found in hindcast from other Clouds Above the United States and Errors at the Surface studies. In Atmospheric Model Intercomparison Project simulations, biases in meridional wind velocity associated with the low-level jet and the 500 hPa vertical velocity may also relate to T2 m bias through their control on the surface energy and water budget.

Arm motion coupling during locomotion-like actions: An experimental study and a dynamic model

PubMed Central

Shapkova, E.Yu; Terekhov, A.V.; Latash, M.L.

2010-01-01

We studied the coordination of arm movements in standing persons who performed an out-of-phase arm-swinging task while stepping in place or while standing. The subjects were instructed to stop one of the arms in response to an auditory signal while trying to keep the rest of the movement pattern unchanged. A significant increase was observed in the amplitude of the arm that continued swinging under both the stepping and standing conditions. This increase was similar between the right and left arms. A dynamic model was developed including two coupled non-linear van der Pol oscillators. We assumed that stopping an arm did not eliminate the coupling but introduced a new constraint. Within the model, superposition of two factors, a command to stop the ongoing movement of one arm and the coupling between the two oscillators, has been able to account for the observed effects. The model makes predictions for future experiments. PMID:21628725

Real-time simulation of three-dimensional shoulder girdle and arm dynamics.

PubMed

Chadwick, Edward K; Blana, Dimitra; Kirsch, Robert F; van den Bogert, Antonie J

2014-07-01

Electrical stimulation is a promising technology for the restoration of arm function in paralyzed individuals. Control of the paralyzed arm under electrical stimulation, however, is a challenging problem that requires advanced controllers and command interfaces for the user. A real-time model describing the complex dynamics of the arm would allow user-in-the-loop type experiments where the command interface and controller could be assessed. Real-time models of the arm previously described have not included the ability to model the independently controlled scapula and clavicle, limiting their utility for clinical applications of this nature. The goal of this study therefore was to evaluate the performance and mechanical behavior of a real-time, dynamic model of the arm and shoulder girdle. The model comprises seven segments linked by eleven degrees of freedom and actuated by 138 muscle elements. Polynomials were generated to describe the muscle lines of action to reduce computation time, and an implicit, first-order Rosenbrock formulation of the equations of motion was used to increase simulation step-size. The model simulated flexion of the arm faster than real time, simulation time being 92% of actual movement time on standard desktop hardware. Modeled maximum isometric torque values agreed well with values from the literature, showing that the model simulates the moment-generating behavior of a real human arm. The speed of the model enables experiments where the user controls the virtual arm and receives visual feedback in real time. The ability to optimize potential solutions in simulation greatly reduces the burden on the user during development.

Study of design and control of remote manipulators. Modeling manipulator arms with distributed flexibility for design and control

NASA Technical Reports Server (NTRS)

Book, W. J.

1974-01-01

The interactions of control system and distributed flexible structural dynamics is explored for mechanical arms. A modeling process using 4 x 4 transfer matrices is described which permits the closed loop response of many current arm configurations to be evaluated. Root locus, frequency response, modal shapes, and time impulse response have all been obtained from the digital computer implementation of this model, which is oriented to arm design and allows for easy variation of the arm configuration through data cards. The model corresponds with experimentally observed natural frequencies with an average error of less than 5% in the first three flexible modes in the seven cases considered. The model was used to explore the limits imposed by structural flexibility on a nondimensionalized two link arm with one and two joints for planar motion.

Observations and Modeling of the Green Ocean Amazon: Sounding Enhancement Field Campaign Report

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

Schumacher, Courtney

2016-05-01

The goal of this campaign was to provide higher temporal sampling of the vertical structure of the atmosphere during the two intensive observational periods (IOPs) of the GoAmazon 2014/15 campaign. The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s first ARM Mobile Facility (AMF1) baseline launches for 2014 and 2015 was 4 sondes/day at 2 am, 8 am, 2 pm, and 8 pm local time (LT) (6, 12, 18 and 0 Coordinated Universal Time [UTC]). However, rapid changes in boundary layer and free tropospheric temperature, humidity, and wind profiles happen throughout the diurnal cycle over Manaus,more » Brazil's complex forest canopy with resulting responses in aerosol, cloud, and precipitation characteristics. This campaign increased sampling to 5 sondes/day for the 2014 wet and dry season IOPs by adding a launch at 11 am (15 UTC) to capture rapid changes in boundary layer properties and convective cloud growth during that time. The extra launch also corresponded to the time of day the ARM Gulfstream (G-1) and German HALO aircraft most often flew, thus providing useful measurements of the large-scale environment during the flights. In addition, the extra launch will significantly add to the quality of AMF1 instrument retrievals and variational analysis forcing data set during the IOPs.« less

A Unified Approach for Reporting ARM Measurement Uncertainties Technical Report

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

Campos, E; Sisterson, Douglas

The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility is observationally based, and quantifying the uncertainty of its measurements is critically important. With over 300 widely differing instruments providing over 2,500 datastreams, concise expression of measurement uncertainty is quite challenging. The ARM Facility currently provides data and supporting metadata (information about the data or data quality) to its users through a number of sources. Because the continued success of the ARM Facility depends on the known quality of its measurements, the Facility relies on instrument mentors and the ARM Data Quality Office (DQO) to ensure, assess,more » and report measurement quality. Therefore, an easily accessible, well-articulated estimate of ARM measurement uncertainty is needed. Note that some of the instrument observations require mathematical algorithms (retrievals) to convert a measured engineering variable into a useful geophysical measurement. While those types of retrieval measurements are identified, this study does not address particular methods for retrieval uncertainty. As well, the ARM Facility also provides engineered data products, or value-added products (VAPs), based on multiple instrument measurements. This study does not include uncertainty estimates for those data products. We propose here that a total measurement uncertainty should be calculated as a function of the instrument uncertainty (calibration factors), the field uncertainty (environmental factors), and the retrieval uncertainty (algorithm factors). The study will not expand on methods for computing these uncertainties. Instead, it will focus on the practical identification, characterization, and inventory of the measurement uncertainties already available in the ARM community through the ARM instrument mentors and their ARM instrument handbooks. As a result, this study will address the first steps towards reporting ARM measurement uncertainty: 1) identifying how the uncertainty of individual ARM measurements is currently expressed, 2) identifying a consistent approach to measurement uncertainty, and then 3) reclassifying ARM instrument measurement uncertainties in a common framework.« less

Inching toward Armageddon: a psychiatric view.

PubMed

Abraham, H D

1983-01-01

The existence of thermonuclear arsenals capable of destroying much of humanity takes its origins from, and has an influence on, processes that are largely psychological. The threat to use a single nuclear bomb to resolve contemporary conflict is an anathema in part because complex nation-states did not evolve with surviving a nuclear war in mind. The atomic arms race has proceeded apace because of maladaptive psychological mechanism including denial, distortion, projection, and, most relevantly, the need to enhance bonding within groups by creating stereotypes. One consequence of the arms race is a climate of fear and hopelessness, and especially destructive effect of which is seen in children. The physician's role in the prevention of nuclear war is critical, but divided between contradictory roles. On one hand, the physician is traditionally identified as a non-political advocate of the sick; on the other, as an advocate for the public health. It is this second model that enables physicians most legitimately to work for the prevention of nuclear war and to deal with the psychiatric concomitants of a planet drifting toward disaster.

Inching toward Armageddon: a psychiatric view.

PubMed Central

Abraham, H. D.

1983-01-01

The existence of thermonuclear arsenals capable of destroying much of humanity takes its origins from, and has an influence on, processes that are largely psychological. The threat to use a single nuclear bomb to resolve contemporary conflict is an anathema in part because complex nation-states did not evolve with surviving a nuclear war in mind. The atomic arms race has proceeded apace because of maladaptive psychological mechanism including denial, distortion, projection, and, most relevantly, the need to enhance bonding within groups by creating stereotypes. One consequence of the arms race is a climate of fear and hopelessness, and especially destructive effect of which is seen in children. The physician's role in the prevention of nuclear war is critical, but divided between contradictory roles. On one hand, the physician is traditionally identified as a non-political advocate of the sick; on the other, as an advocate for the public health. It is this second model that enables physicians most legitimately to work for the prevention of nuclear war and to deal with the psychiatric concomitants of a planet drifting toward disaster. PMID:6636836

The Continuous Intercomparison of Radiation Codes (CIRC): Phase I Cases

NASA Technical Reports Server (NTRS)

Oreopoulos, Lazaros; Mlawer, Eli; Delamere, Jennifer; Shippert, Timothy; Turner, David D.; Miller, Mark A.; Minnis, Patrick; Clough, Shepard; Barker, Howard; Ellingson, Robert

2007-01-01

CIRC aspires to be the successor to ICRCCM (Intercomparison of Radiation Codes in Climate Models). It is envisioned as an evolving and regularly updated reference source for GCM-type radiative transfer (RT) code evaluation with the principle goal to contribute in the improvement of RT parameterizations. CIRC is jointly endorsed by DOE's Atmospheric Radiation Measurement (ARM) program and the GEWEX Radiation Panel (GRP). CIRC's goal is to provide test cases for which GCM RT algorithms should be performing at their best, i.e, well characterized clear-sky and homogeneous, overcast cloudy cases. What distinguishes CIRC from previous intercomparisons is that its pool of cases is based on observed datasets. The bulk of atmospheric and surface input as well as radiative fluxes come from ARM observations as documented in the Broadband Heating Rate Profile (BBHRP) product. BBHRP also provides reference calculations from AER's RRTM RT algorithms that can be used to select the most optimal set of cases and to provide a first-order estimate of our ability to achieve radiative flux closure given the limitations in our knowledge of the atmospheric state.

War Induced Aerosol Optical, Microphysical and Radiative Effects

NASA Astrophysics Data System (ADS)

Munshi, Pavel; Tiwari, Shubhansh

2017-01-01

The effect of war on air pollution and climate is assessed in this communication. War today in respect of civil wars and armed conflict in the Middle East area is taken into consideration. Impacts of war are not only in loss of human life and property, but also in the environment. It is well known that war effects air pollution and in the long run contribute to anthropogenic climate change, but general studies on this subject are few because of the difficulties of observations involved. In the current scenario of the ongoing conflict in the Middle East regions, deductions in parameters of atmosphere are discussed. Aerosol Optical Depth, Aerosol loads, Black Carbon, Ozone,Dust, regional haze and many more are analyzed using various satellite data. Multi-model analysis is also studied to verify the analysis. Type segregation of aerosols, in-depth constraints to atmospheric chemistry, biological effects and particularly atmospheric physics in terms of radiative forcing, etc. are discussed. Undergraduate in Earth Sciences.

AMIE Gan Island Ancillary Disdrometer Field Campaign Report

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

Oue, Mariko

2016-04-01

As part of the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement Climate Research Facility (ARM) Madden-Julian Oscillation (MJO) Investigation Experiment (AMIE), in January 2012 a disdrometer observation took place with the second ARM Mobile Facility (AMF2), the Scanning ARM Cloud Radar (SACR), the Texas A&M SMART-R C-band radar, and the National Center for Atmospheric Research (NCAR) dual wavelength S- and Ka-bands polarimetric (SPolKa) radar on Gan Island, Maldives. In order to measure raindrop size distributions, a disdrometer of Nagoya University, Japan, was set up close to the ARM Two-Dimensional (2D) Video Disdrometer (2DVD). The SMART-R and SPolKa radars performedmore » range-height-indicator scanning in the direction of the disdrometer site. Comparing the disdrometer data with 2DVD data, the raindrop size distribution data will be calibrated. Furthermore, the analysis of the raindrop size distribution and radar data will be expected to clarify the microphysics in tropical convective clouds.« less

Neck Muscle Moment Arms Obtained In-Vivo from MRI: Effect of Curved and Straight Modeled Paths.

PubMed

Suderman, Bethany L; Vasavada, Anita N

2017-08-01

Musculoskeletal models of the cervical spine commonly represent neck muscles with straight paths. However, straight lines do not best represent the natural curvature of muscle paths in the neck, because the paths are constrained by bone and soft tissue. The purpose of this study was to estimate moment arms of curved and straight neck muscle paths using different moment arm calculation methods: tendon excursion, geometric, and effective torque. Curved and straight muscle paths were defined for two subject-specific cervical spine models derived from in vivo magnetic resonance images (MRI). Modeling neck muscle paths with curvature provides significantly different moment arm estimates than straight paths for 10 of 15 neck muscles (p < 0.05, repeated measures two-way ANOVA). Moment arm estimates were also found to be significantly different among moment arm calculation methods for 11 of 15 neck muscles (p < 0.05, repeated measures two-way ANOVA). In particular, using straight lines to model muscle paths can lead to overestimating neck extension moment. However, moment arm methods for curved paths should be investigated further, as different methods of calculating moment arm can provide different estimates.

Investigation of the radiative forcings of thin cirrus in the tropical atmosphere using remote sensing data

NASA Astrophysics Data System (ADS)

Yue, Qing

Cirrus clouds have a unique influence on the climate system through their effects on the radiation budget of the earth and the atmosphere. To better understand the radiative effect of cirrus clouds, the microphysical and radiative properties of these clouds, especially tropical thin cirrus clouds, are studied based on both insitu cirrus measurements and satellite remote sensing observations. We perform a correlation analysis involving ice water content (IWC) and mean effective diameter (De) for applications to radiative transfer calculations and climate models using insitu measurements obtained from numerous field campaigns in the tropics, midlatitude, and Arctic regions. In conjunction with the study of cirrus clouds, we develop a high-resolution spectral infrared radiative transfer model for thin cirrus cloudy atmosphere, which is employed to retrieve De and cirrus optical depth from the Atmospheric Infrared Sounder (AIRS) infrared spectra. Numerical simulations show that cirrus cloudy radiances in the 800-1130 cm-1 thermal infrared window are sufficiently sensitive to variations in cirrus optical depth, and ice crystal size and habit. A number of nighttime thin cirrus scenes over the Atmospheric Radiation Measurement (ARM) program's Tropical Western Pacific sites have been selected from AIRS datasets for this study. The radiative transfer model is applied to these selected cases to determine cirrus optical depth, De and habit factors. Solar and infrared radiative forcings and heating rates produced by thin cirrus in the tropical atmosphere have been calculated using the retrieved cirrus optical and microphysical properties along with a modified Fu and Liou broadband radiative transfer scheme to analyze their dependence on cirrus cloud properties. Generally, larger TOA warming and smaller surface warming are associated with higher cirrus clouds. To cross-check the validity of our model, the collocated and coincident surface radiation measurements taken by ARM pyrgeometers have been compared with the calculated surface fluxes. Using the method developed in this study, regional radiation budget analyses can be carried out in the future study to quantitatively understand the role of thin cirrus clouds on solar and thermal infrared radiative forcings at the top of the atmosphere, the tropopause, and the surface.

THE STRUCTURE OF SPIRAL SHOCKS EXCITED BY PLANETARY-MASS COMPANIONS

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

Zhu, Zhaohuan; Stone, James M.; Rafikov, Roman R.

2015-11-10

Direct imaging observations have revealed spiral structures in protoplanetary disks. Previous studies have suggested that planet-induced spiral arms cannot explain some of these spiral patterns, due to the large pitch angle and high contrast of the spiral arms in observations. We have carried out three-dimensional (3D) hydrodynamical simulations to study spiral wakes/shocks excited by young planets. We find that, in contrast with linear theory, the pitch angle of spiral arms does depend on the planet mass, which can be explained by the nonlinear density wave theory. A secondary (or even a tertiary) spiral arm, especially for inner arms, is alsomore » excited by a massive planet. With a more massive planet in the disk, the excited spiral arms have larger pitch angle and the separation between the primary and secondary arms in the azimuthal direction is also larger. We also find that although the arms in the outer disk do not exhibit much vertical motion, the inner arms have significant vertical motion, which boosts the density perturbation at the disk atmosphere. Combining hydrodynamical models with Monte-Carlo radiative transfer calculations, we find that the inner spiral arms are considerably more prominent in synthetic near-IR images using full 3D hydrodynamical models than images based on two-dimensional models assuming vertical hydrostatic equilibrium, indicating the need to model observations with full 3D hydrodynamics. Overall, companion-induced spiral arms not only pinpoint the companion’s position but also provide three independent ways (pitch angle, separation between two arms, and contrast of arms) to constrain the companion’s mass.« less

Large Eddy Simulations of Continental Boundary Layer Clouds Observed during the RACORO Field Campaign

NASA Astrophysics Data System (ADS)

Endo, S.; Fridlind, A. M.; Lin, W.; Vogelmann, A. M.; Toto, T.; Liu, Y.

2013-12-01

Three cases of boundary layer clouds are analyzed in the FAst-physics System TEstbed and Research (FASTER) project, based on continental boundary-layer-cloud observations during the RACORO Campaign [Routine Atmospheric Radiation Measurement (ARM) Aerial Facility (AAF) Clouds with Low Optical Water Depths (CLOWD) Optical Radiative Observations] at the ARM Climate Research Facility's Southern Great Plains (SGP) site. The three 60-hour case study periods are selected to capture the temporal evolution of cumulus, stratiform, and drizzling boundary-layer cloud systems under a range of conditions, intentionally including those that are relatively more mixed or transitional in nature versus being of a purely canonical type. Multi-modal and temporally varying aerosol number size distribution profiles are derived from aircraft observations. Large eddy simulations (LESs) are performed for the three case study periods using the GISS Distributed Hydrodynamic Aerosol and Radiative Modeling Application (DHARMA) model and the WRF-FASTER model, which is the Weather Research and Forecasting (WRF) model implemented with forcing ingestion and other functions to constitute a flexible LES. The two LES models commonly capture the significant transitions of cloud-topped boundary layers in the three periods: diurnal evolution of cumulus layers repeating over multiple days, nighttime evolution/daytime diminution of thick stratus, and daytime breakup of stratus and stratocumulus clouds. Simulated transitions of thermodynamic structures of the cloud-topped boundary layers are examined by balloon-borne soundings and ground-based remote sensors. Aircraft observations are then used to statistically evaluate the predicted cloud droplet number size distributions under varying aerosol and cloud conditions. An ensemble approach is used to refine the model configuration for the combined use of observations with parallel LES and single-column model simulations. See Lin et al. poster for single-column model investigation.

A Kinematic Calibration Process for Flight Robotic Arms

NASA Technical Reports Server (NTRS)

Collins, Curtis L.; Robinson, Matthew L.

2013-01-01

The Mars Science Laboratory (MSL) robotic arm is ten times more massive than any Mars robotic arm before it, yet with similar accuracy and repeatability positioning requirements. In order to assess and validate these requirements, a higher-fidelity model and calibration processes were needed. Kinematic calibration of robotic arms is a common and necessary process to ensure good positioning performance. Most methodologies assume a rigid arm, high-accuracy data collection, and some kind of optimization of kinematic parameters. A new detailed kinematic and deflection model of the MSL robotic arm was formulated in the design phase and used to update the initial positioning and orientation accuracy and repeatability requirements. This model included a higher-fidelity link stiffness matrix representation, as well as a link level thermal expansion model. In addition, it included an actuator backlash model. Analytical results highlighted the sensitivity of the arm accuracy to its joint initialization methodology. Because of this, a new technique for initializing the arm joint encoders through hardstop calibration was developed. This involved selecting arm configurations to use in Earth-based hardstop calibration that had corresponding configurations on Mars with the same joint torque to ensure repeatability in the different gravity environment. The process used to collect calibration data for the arm included the use of multiple weight stand-in turrets with enough metrology targets to reconstruct the full six-degree-of-freedom location of the rover and tool frames. The follow-on data processing of the metrology data utilized a standard differential formulation and linear parameter optimization technique.

Evaluation of the NASA GISS AR5 SCM/GCM at the ARM SGP Site using Self Organizing Maps

NASA Astrophysics Data System (ADS)

Kennedy, A. D.; Dong, X.; Xi, B.; Del Genio, A. D.; Wolf, A.

2011-12-01

Understanding and improving clouds in climate models requires moving beyond comparing annual and seasonal means. Errors can offset resulting in models getting the right long-term solution for the wrong reasons. For example, cloud parameterization errors may be balanced by the model incorrectly simulating the frequency distribution of atmospheric states. To faithfully evaluate climate models it is necessary to partition results into specific regimes. This has been completed in the past by evaluating models by their ability to produce cloud regimes as determined by observational products from satellites. An alternative approach is to first classify meteorological regimes (i.e., synoptic pattern and forcing) and then determine what types of clouds occur for each class. In this study, a competitive neural network known as the Self Organizing Map (SOM) is first used to classify synoptic patterns from a reanalysis over the Southern Great Plains (SGP) region during the period 1999-2008. These results are then used to evaluate simulated clouds from the AR5 version of the NASA GISS Model E Single Column Model (SCM). Unlike past studies that narrowed classes into several categories, this study assumes that the atmosphere is capable of producing an infinite amount of states. As a result, SOMs were generated with a large number of classes for specific months when model errors were found. With nearly ten years of forcing data, an adequate number of samples have been used to determine how cloud fraction varies across the SOM and to distinguish cloud errors. Barring major forcing errors, SCM studies can be thought of as what the GCM would simulate if the dynamics were perfect. As a result, simulated and observed CFs frequently occur for the same atmospheric states. For example, physically deep clouds during the winter months occur for a small number of classes in the SOM. Although the model produces clouds during the correct states, CFs are consistently too low. Instead, the model has a positive bias of thinner clouds during these classes that were associated with low-pressure systems and fronts. To determine if this and other SCM errors are present in the GCM, the Atmospheric Model Intercomparison Project (AMIP) run for the NASA GISS GCM will also be investigated. The SOM will be used to classify atmospheric states within the GCM to determine how well the GCM captures the PDF of observed atmospheric states. Together, these comparisons will allow for a thorough evaluation of the model at the ARM SGP site.

The relation between magnetic and material arms in models for spiral galaxies

NASA Astrophysics Data System (ADS)

Moss, D.; Beck, R.; Sokoloff, D.; Stepanov, R.; Krause, M.; Arshakian, T. G.

2013-08-01

Context. Observations of polarized radio emission show that large-scale (regular) magnetic fields in spiral galaxies are not fully axisymmetric, but generally stronger in interarm regions. In some nearby galaxies such as NGC 6946 they are organized in narrow magnetic arms situated between the material spiral arms. Aims: The phenomenon of magnetic arms and their relation to the optical spiral arms (the material arms) calls for an explanation in the framework of galactic dynamo theory. Several possibilities have been suggested but are not completely satisfactory; here we attempt a consistent investigation. Methods: We use a 2D mean-field dynamo model in the no-z approximation and add injections of small-scale magnetic field, taken to result from supernova explosions, to represent the effects of dynamo action on smaller scales. This injection of small scale field is situated along the spiral arms, where star-formation mostly occurs. Results: A straightforward explanation of magnetic arms as a result of modulation of the dynamo mechanism by material arms struggles to produce pronounced magnetic arms, at least with realistic parameters, without introducing new effects such as a time lag between Coriolis force and α-effect. In contrast, by taking into account explicitly the small-scale magnetic field that is injected into the arms by the action of the star forming regions that are concentrated there, we can obtain dynamo models with magnetic structures of various forms that can be compared with magnetic arms. These are rather variable entities and their shape changes significantly on timescales of a few 100 Myr. Properties of magnetic arms can be controlled by changing the model parameters. In particular, a lower injection rate of small-scale field makes the magnetic configuration smoother and eliminates distinct magnetic arms. Conclusions: We conclude that magnetic arms can be considered as coherent magnetic structures generated by large-scale dynamo action, and associated with spatially modulated small-scale magnetic fluctuations, caused by enhanced star formation rates within the material arms.

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

Voyles, J. W.; Chapman, L. A.

This document establishes a common set of guidelines for the Atmospheric Radiation Measurement (ARM) Climate Research Facility for planning, executing, and closing out field campaigns. The steps that guide individual field campaigns are described in the Field Campaign Tracking System and are specifically tailored to meet the scope of each field campaign.

Observational Evidence of Changes in Water Vapor, Clouds, and Radiation at the ARM SGP Site

NASA Technical Reports Server (NTRS)

Dong, Xiquan; Xi, Baike; Minnis, Patrick

2006-01-01

Characterizing water vapor and cloud effects on the surface radiation budget is critical for understanding the current climate because water vapor is the most important greenhouse gas in the atmosphere and clouds are one of the largest sources of uncertainty in predicting potential future climate change. Several studies have shown that insolation over land declined until 1990 then increased until the present. Using 8 years of data collected at the ARM Southern Great Plains (SGP) surface site, we found that the insolation increased from 1997 to 2000, but significantly decreased from 2001 to 2004, changes that exactly mirror the variation in the second-order fit of cloud fraction. Under clear-sky conditions, the rates of water vapor, insolation and downwelling longwave (LW) flux are -0.166 cm/yr, 0.48 Wm(exp -2)/yr, and -1.16 Wm(exp -2)/yr, respectively, indicating that water vapor changes are more important for LW flux than for insolation.

Global Modeling of Spur Formation in Spiral Galaxies

NASA Astrophysics Data System (ADS)

Shetty, Rahul; Ostriker, Eve C.

2006-08-01

We investigate the formation of substructure in spiral galaxies using global MHD simulations, including gas self-gravity. Local modeling by Kim & Ostriker previously showed that self-gravity and magnetic fields cause rapid growth of overdensities in spiral arms; differential compression of gas flowing through the arms then results in the formation of sheared structures in the interarms. These sheared structures resemble features described as spurs or feathers in optical and IR observations of many spiral galaxies. Global modeling extends previous local models by including the full effects of curvilinear coordinates, a realistic log-spiral perturbation, self-gravitational contribution from five radial wavelengths of the spiral shock, and variation of density and epicyclic frequency with radius. We show that with realistic Toomre Q-values self-gravity and galactic differential rotation produce filamentary gaseous structures with kiloparsec-scale separations, regardless of the strength-or even presence-of a stellar spiral potential. However, a sufficiently strong spiral potential is required to produce true spurs, consisting of interarm structures emerging from gas concentrations in the main spiral arms. In models where Q is initially constant, filaments due to interarm self-gravity grow mainly in the outer regions, whereas true arm spurs grow only in the inner regions. For models with Q~R, outer regions are intrinsically more stable, so background interarm filaments do not grow, but arm spurs can develop if the spiral potential is strong. Unlike independently growing background filaments, the orientation of arm spurs depends on galactic location. Inside corotation, spurs emanate outward, on the convex side of the arm; outside corotation, spurs grow inward, on the concave side of the arm. Based on orientation and the relation to arm clumps, it is possible to distinguish true spurs that originate as instabilities in the arms from independently growing background filaments. We measure spur spacings of ~3-5 times the Jeans length in the arm and arm clump masses of ~107 Msolar. Finally, we have also studied models without self-gravity, finding that magnetic fields suppress a purely hydrodynamic instability recently proposed by Wada & Koda as a means of growing interarm spurs and feathers. Our models also suggest that magnetic fields are important in preserving grand-design spiral structure when gas in the arms fragments via self-gravity into GMCs.

Global Agriculture Yields and Conflict under Future Climate

NASA Astrophysics Data System (ADS)

Rising, J.; Cane, M. A.

2013-12-01

Aspects of climate have been shown to correlate significantly with conflict. We investigate a possible pathway for these effects through changes in agriculture yields, as predicted by field crop models (FAO's AquaCrop and DSSAT). Using satellite and station weather data, and surveyed data for soil and management, we simulate major crop yields across all countries between 1961 and 2008, and compare these to FAO and USDA reported yields. Correlations vary by country and by crop, from approximately .8 to -.5. Some of this range in crop model performance is explained by crop varieties, data quality, and other natural, economic, and political features. We also quantify the ability of AquaCrop and DSSAT to simulate yields under past cycles of ENSO as a proxy for their performance under changes in climate. We then describe two statistical models which relate crop yields to conflict events from the UCDP/PRIO Armed Conflict dataset. The first relates several preceding years of predicted yields of the major grain in each country to any conflict involving that country. The second uses the GREG ethnic group maps to identify differences in predicted yields between neighboring regions. By using variation in predicted yields to explain conflict, rather than actual yields, we can identify the exogenous effects of weather on conflict. Finally, we apply precipitation and temperature time-series under IPCC's A1B scenario to the statistical models. This allows us to estimate the scale of the impact of future yields on future conflict. Centroids of the major growing regions for each country's primary crop, based on USDA FAS consumption. Correlations between simulated yields and reported yields, for AquaCrop and DSSAT, under the assumption that no irrigation, fertilization, or pest control is used. Reported yields are the average of FAO yields and USDA FAS yields, where both are available.

Clouds, Aerosols, and Precipitation in the Marine Boundary Layer: An Arm Mobile Facility Deployment

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

Wood, Robert; Wyant, Matthew; Bretherton, Christopher S.

The Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (CAP-MBL) deployment at Graciosa Island in the Azores generated a 21 month (April 2009-December 2010) comprehensive dataset documenting clouds, aerosols and precipitation using the Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF). The scientific aim of the deployment is to gain improved understanding of the interactions of clouds, aerosols and precipitation in the marine boundary layer. Graciosa Island straddles the boundary between the subtropics and midlatitudes in the Northeast Atlantic Ocean, and consequently experiences a great diversity of meteorological and cloudiness conditions. Low clouds are the dominant cloud type, with stratocumulusmore » and cumulus occurring regularly. Approximately half of all clouds contained precipitation detectable as radar echoes below the cloud base. Radar and satellite observations show that clouds with tops from 1- 11 km contribute more or less equally to surface-measured precipitation at Graciosa. A wide range of aerosol conditions was sampled during the deployment consistent with the diversity of sources as indicated by back trajectory analysis. Preliminary findings suggest important two-way interactions between aerosols and clouds at Graciosa, with aerosols affecting light precipitation and cloud radiative properties while being controlled in part by precipitation scavenging. The data from at Graciosa are being compared with short-range forecasts made a variety of models. A pilot analysis with two climate and two weather forecast models shows that they reproduce the observed time-varying vertical structure of lower-tropospheric cloud fairly well, but the cloud-nucleating aerosol concentrations less well. The Graciosa site has been chosen to be a permanent fixed ARM site that became operational in October 2013.« less

Clouds, aerosol, and precipitation in the Marine Boundary Layer: An ARM mobile facility deployment

DOE PAGES

Wood, Robert; Luke, Ed; Wyant, Matthew; ...

2014-04-27

The Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (CAP-MBL) deployment at Graciosa Island in the Azores generated a 21-month (April 2009-December 2010) comprehensive dataset documenting clouds, aerosols, and precipitation using the Atmospheric Radiation Measurement Program (ARM) Mobile Facility (AMF). The scientific aim of the deployment is to gain improved understanding of the interactions of clouds, aerosols, and precipitation in the marine boundary layer. Graciosa Island straddles the boundary between the subtropics and midlatitudes in the Northeast Atlantic Ocean and consequently experiences a great diversity of meteorological and cloudiness conditions. Low clouds are the dominant cloud type, with stratocumulusmore » and cumulus occurring regularly. Approximately half of all clouds contained precipitation detectable as radar echoes below the cloud base. Radar and satellite observations show that clouds with tops from 1-11 km contribute more or less equally to surface-measured precipitation at Graciosa. A wide range of aerosol conditions was sampled during the deployment consistent with the diversity of sources as indicated by back-trajectory analysis. Preliminary findings suggest important two-way interactions between aerosols and clouds at Graciosa, with aerosols affecting light precipitation and cloud radiative properties while being controlled in part by precipitation scavenging.The data from Graciosa are being compared with short-range forecasts made with a variety of models. A pilot analysis with two climate and two weather forecast models shows that they reproduce the observed time-varying vertical structure of lower-tropospheric cloud fairly well but the cloud-nucleating aerosol concentrations less well. The Graciosa site has been chosen to be a permanent fixed ARM site that became operational in October 2013.« less

Clouds, Aerosols, and Precipitation in the Marine Boundary Layer: An Arm Mobile Facility Deployment

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

Wood, Robert; Wyant, Matthew; Bretherton, Christopher S.

The Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (CAP-MBL) 38 deployment at Graciosa Island in the Azores generated a 21 month (April 2009-December 2010) 39 comprehensive dataset documenting clouds, aerosols and precipitation using the Atmospheric 40 Radiation Measurement (ARM) Mobile Facility (AMF). The scientific aim of the deployment is 41 to gain improved understanding of the interactions of clouds, aerosols and precipitation in the 42 marine boundary layer. 43 Graciosa Island straddles the boundary between the subtropics and midlatitudes in the 44 Northeast Atlantic Ocean, and consequently experiences a great diversity of meteorological and 45 cloudiness conditions. Lowmore » clouds are the dominant cloud type, with stratocumulus and cumulus 46 occurring regularly. Approximately half of all clouds contained precipitation detectable as radar 47 echoes below the cloud base. Radar and satellite observations show that clouds with tops from 1-48 11 km contribute more or less equally to surface-measured precipitation at Graciosa. A wide 49 range of aerosol conditions was sampled during the deployment consistent with the diversity of 50 sources as indicated by back trajectory analysis. Preliminary findings suggest important two-way 51 interactions between aerosols and clouds at Graciosa, with aerosols affecting light precipitation 52 and cloud radiative properties while being controlled in part by precipitation scavenging. 53 The data from at Graciosa are being compared with short-range forecasts made a variety 54 of models. A pilot analysis with two climate and two weather forecast models shows that they 55 reproduce the observed time-varying vertical structure of lower-tropospheric cloud fairly well, 56 but the cloud-nucleating aerosol concentrations less well. The Graciosa site has been chosen to 57 be a long-term ARM site that became operational in October 2013.« less

Continental Shallow Convection Cloud-Base Mass Flux from Doppler Lidar and LASSO Ensemble Large-Eddy Simulations

NASA Astrophysics Data System (ADS)

Vogelmann, A. M.; Zhang, D.; Kollias, P.; Endo, S.; Lamer, K.; Gustafson, W. I., Jr.; Romps, D. M.

2017-12-01

Continental boundary layer clouds are important to simulations of weather and climate because of their impact on surface budgets and vertical transports of energy and moisture; however, model-parameterized boundary layer clouds do not agree well with observations in part because small-scale turbulence and convection are not properly represented. To advance parameterization development and evaluation, observational constraints are needed on critical parameters such as cloud-base mass flux and its relationship to cloud cover and the sub-cloud boundary layer structure including vertical velocity variance and skewness. In this study, these constraints are derived from Doppler lidar observations and ensemble large-eddy simulations (LES) from the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) Facility Southern Great Plains (SGP) site in Oklahoma. The Doppler lidar analysis will extend the single-site, long-term analysis of Lamer and Kollias [2015] and augment this information with the short-term but unique 1-2 year period since five Doppler lidars began operation at the SGP, providing critical information on regional variability. These observations will be compared to the statistics obtained from ensemble, routine LES conducted by the LES ARM Symbiotic Simulation and Observation (LASSO) project (https://www.arm.gov/capabilities/modeling/lasso). An Observation System Simulation Experiment (OSSE) will be presented that uses the LASSO LES fields to determine criteria for which relationships from Doppler lidar observations are adequately sampled to yield convergence. Any systematic differences between the observed and simulated relationships will be examined to understand factors contributing to the differences. Lamer, K., and P. Kollias (2015), Observations of fair-weather cumuli over land: Dynamical factors controlling cloud size and cover, Geophys. Res. Lett., 42, 8693-8701, doi:10.1002/2015GL064534

Domain-averaged, Shallow Precipitation Measurements During the Aerosol and Cloud Experiments in the Eastern North Atlantic (ACE-ENA)

NASA Astrophysics Data System (ADS)

Lamer, K.; Luke, E. P.; Kollias, P.; Oue, M.; Wang, J.

2017-12-01

The Atmospheric Radiation Measurement (ARM) Climate Research Facility operates a fixed observatory in the Eastern North Atlantic (ENA) on Graciosa Island in the Azores. Straddling the tropics and extratropics, the Azores receive air transported from North America, the Arctic and sometimes Europe. At the ARM ENA site, marine boundary layer clouds are frequently observed all year round. Estimates of drizzle mass flux from the surface to cloud base height are documented using a combination of high sensitivity profiling 35-GHz radar and ceilometer observations. Three years of drizzle mass flux retrievals reveal that statistically, directly over the ENA site, marine boundary layer cloud drizzle rates tend to be weak with few heavy drizzle events. In the summer of 2017, this site hosted the first phase of the Aerosol and Cloud Experiments in the Eastern North Atlantic (ACE-ENA) field campaign, which is motivated by the need for comprehensive in situ characterization of boundary layer structure, low clouds and aerosols. During this phase, the 35-GHz scanning ARM cloud radar was operated as a surveillance radar, providing regional context for the profiling observations. While less sensitive, the scanning radar measurements document a larger number of heavier drizzle events and provide domain-representative estimates of shallow precipitation. A best estimate, domain averaged, shallow precipitation rate for the region around the ARM ENA site is presented. The methodology optimally combines the ability of the profiling observations to detect the weak but frequently occurring drizzle events with the scanning cloud radar's ability to capture the less frequent heavier drizzle events. The technique is also evaluated using high resolution model output and a sophisticated forward radar operator.

CATS Installed on ISS

NASA Image and Video Library

2017-12-08

On Jan. 22, 2015, robotic flight controllers successfully installed NASA’s Cloud Aerosol Transport System (CATS) onboard the International Space Station. CATS will collect data about clouds, volcanic ash plumes and tiny airborne particles that can help improve our understanding of aerosol and cloud interactions, and improve the accuracy of climate change models. CATS had been mounted inside the SpaceX Dragon cargo craft’s unpressurized trunk since it docked at the station on Jan. 12. Ground controllers at NASA’s Johnson Space Center in Houston, Texas, used one of the space station’s robotic arms, called the Special Purpose Dexterous Manipulator, to extract the instrument from the capsule. The NASA-controlled arm passed the instrument to a second robotic arm— like passing a baton in a relay race. This second arm, called the Japanese Experiment Module Remote Manipulator System, is controlled by the Japanese Aerospace Exploration Agency. The Japanese-controlled arm installed the instrument to the Space Station’s Japanese Experiment Module, making CATS the first NASA-developed payload to fly on the Japanese module. CATS is a lidar remote-sensing instrument designed to last from six months to three years. It is specifically intended to demonstrate a low-cost, streamlined approach to developing science payloads on the space station. CATS launched aboard the SpaceX Dragon spacecraft on Jan. 10 at Cape Canaveral Air Force Station in Florida. To learn more about the impact of CATS data, visit: www.nasa.gov/cats/ NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Column and Near-surface Aerosol Properties during TCAP: Temporal Changes in a Coastal Region

NASA Astrophysics Data System (ADS)

Kassianov, E.; Barnard, J.; Pekour, M. S.; Berg, L. K.; Shilling, J. E.; Fast, J. D.; Michalsky, J. J.; Lantz, K. O.; Hodges, G.

2013-12-01

An important problem facing climate-related studies is to separate the impacts of naturally occurring and anthropogenic aerosol. This problem is even more challenging in coastal regions located downwind of large metropolitan areas. Cape Cod situated on the easternmost portion of Massachusetts (along the east coast of the United States) is an example of one of these regions. The Two-Column Aerosol Project (TCAP; http://campaign.arm.gov/tcap/) was designed to study the evolution of optical, microphysical and chemical properties of both marine aerosol and aerosol transported from North America to the Atlantic as well as their impact on the radiation energy budget. The TCAP has been recently conducted (2012-2013) on Cape Cod with support from the U.S. Department of Energy's (DOE's) Atmospheric Radiation Measurement (ARM) Program (http://www.arm.gov/). During the TCAP, the ground-based ARM Mobile Facility (AMF) was deployed on Cape Cod. The AMF site (at 41.87°N; 70.28°W) was equipped with numerous instruments for sampling aerosol, cloud and radiative properties, including a Multi-Filter Rotating Shadowband Radiometer (MFRSR), a Scanning Mobility Particle Sizer (SMPS), an Aerodynamic Particle Sizer (APS), a three-wavelength nephelometer, and suite of instruments to measure the aerosol chemical composition. In this study we present an analysis of diurnal and day-to-day variability of the column and near-surface aerosol properties obtained from remote sensing (MFRSR data) and in situ measurements (SMPS, APS, nephelometer, chemical composition), respectively. The importance of this variability to direct aerosol radiative forcing at different time scales and its relation to the long-range transport will be discussed. Some regional model results will also be presented.

Using Action, Reflection and Modelling (ARM) in Malaysian Primary Schools: Connecting "The ARM Theory" with Student Teachers' Reported Practice

ERIC Educational Resources Information Center

Dickerson, Claire; Jarvis, Joy; Levy, Roger; Thomas, Kit

2017-01-01

This article presents Malaysian student teachers' reports of using an action, reflection and modelling (ARM) pedagogical approach during their placements in Malaysian primary schools. The ARM approach was designed to support the implementation of the Malaysian primary school mathematics curriculum, which involved changing classroom practice in…

AmeriFlux Measurement Component (AMC) Instrument Handbook

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

Reichl, Ken; Biraud, Sebastien C.

2016-04-01

An AMC system was installed at the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility North Slope of Alaska (NSA) Barrow site, also known as NSA C1 at the ARM Data Archive, in August 2012. A second AMC system was installed at the third ARM Mobile Facility deployment at Oliktok Point, also known as NSA M1. This in situ system consists of 12 combination soil temperature and volumetric water content (VWC) reflectometers and one set of upwelling and downwelling photosynthetically active radiation (PAR) sensors, all deployed within the fetch of the Eddy Correlation Flux Measurement System.more » Soil temperature and VWC sensors placed at two depths (10 and 30 cm below the vegetation layer) at six locations (or microsites) allow soil property inhomogeneity to be monitored across a landscape.« less

Using Domain Requirements to Achieve Science-Oriented Provenance

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

Stephan, Eric G; Halter, Todd D; Critchlow, Terence J

2010-06-18

Using Domain Requirements to Achieve Science-Oriented Provenance Eric Stephan1 Todd Halter1 Terence Critchlow1 Paulo Pinheiro da Silva2 Leonardo Salayandia2 1 Pacific Northwest National Laboratory, Richland WA, USA 2 University of Texas at El Paso, El Paso TX, USA Abstract. The US Department of Energy (DOE) Atmospheric Radi- ation Measurement Program (ARM) is adopting the use of formalized provenance to support observational data products produced by ARM operations and relied upon by researchers. Because of the diversity of needs in the climate community provenance will need to be conveyed in a domain-oriented context. This paper explores a use case where semanticmore » abstract workflows (SAW) are employed as a means to filter, aggregate, and contextually describe the historical events responsible for the ARM data product the scientist is relying upon.« less

Uncertainty Estimates for SIRS, SKYRAD, & GNDRAD Data and Reprocessing the Pyrgeometer Data (Presentation)

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

Reda, Ibrahim; Stoffel, Tom; Habte, Aron

2014-03-01

The National Renewable Energy Laboratory (NREL) and the Atmospheric Radiation Measurement (ARM) Climate Research Facility work together in providing data from strategically located in situ measurement observatories around the world. Both work together in improving and developing new technologies that assist in acquiring high quality radiometric data. In this presentation we summarize the uncertainty estimates of the ARM data collected at the ARM Solar Infrared Radiation Station (SIRS), Sky Radiometers on Stand for Downwelling Radiation (SKYRAD), and Ground Radiometers on Stand for Upwelling Radiation (GNDRAD), which ultimately improve the existing radiometric data. Three studies are also included to show themore » difference between calibrating pyrgeometers (e.g., Eppley PIR) using the manufacturer blackbody versus the interim World Infrared Standard Group (WISG), a pyrgeometer aging study, and the sampling rate effect of correcting historical data.« less

Characterizing the Vertical and Spatial Distribution of Black Carbon on the North Slope of Alaska

NASA Astrophysics Data System (ADS)

Sedlacek, A. J., III; Feng, Y.; Biraud, S.; Springston, S. R.

2016-12-01

The Polar Regions are recognized for their pronounced sensitivity to changes in radiative forcing. Indeed, the Cryosphere is often referred to as the `canary in the coalmine' for climate change in the popular literature. It is this sensitivity that provides both motivation and need for targeted measurement campaigns to test the behavior and predictive capabilities of current climate models to so as to improve our understanding of which factors are most important in Arctic climate change. One class of under measured radiative forcing agents in the Polar Region is the absorbing aerosol - black carbon and brown carbon. In particular, the paucity of vertical profile information of BC is partly responsible for the difficulty of reducing uncertainty in model assessment of aerosol radiative impact at high latitudes. During the summer of 2015, a Single-Particle Soot Photometer (SP2) was deployed aboard the DOE Gultstream-1 (G-1) aircraft to measure refractory BC (rBC) concentrations as part of the DOE-sponsored ACME-V (ARM Airborne Carbon Measurements) campaign. This campaign was conducted from June through to mid-September along the North Slope of Alaska and was punctuated by vertical profiling over 5 sites (Atquasuk, Barrow, Ivotuk, Oliktok, and Toolik). In addition, measurement of CO, CO2 and CH4 were also taken to provide information on the spatial and seasonal differences in GHG sources and how these sources correlate with BC. Comparisons between observations and a global climate model (CAM5) simulations will be shown along with a discussion on the ability of the model to capture observed monthly mean profiles of BC and stratified aerosol layers. Additionally, the capability of the SP2 to partition rBC-containing particles into nascent or aged allows an evaluation of how well the CAM5 model captures long distant transported aged carbonaceous aerosols. Finally model sensitivity studies will be presented that investigated the relative importance of the different emission sectors to the summer Arctic BC loadings at different altitudes and the implications of these emissions on the radiation budget.

Dynamic model of the octopus arm. II. Control of reaching movements.

PubMed

Yekutieli, Yoram; Sagiv-Zohar, Roni; Hochner, Binyamin; Flash, Tamar

2005-08-01

The dynamic model of the octopus arm described in the first paper of this 2-part series was used here to investigate the neural strategies used for controlling the reaching movements of the octopus arm. These are stereotypical extension movements used to reach toward an object. In the dynamic model, sending a simple propagating neural activation signal to contract all muscles along the arm produced an arm extension with kinematic properties similar to those of natural movements. Control of only 2 parameters fully specified the extension movement: the amplitude of the activation signal (leading to the generation of muscle force) and the activation traveling time (the time the activation wave takes to travel along the arm). We found that the same kinematics could be achieved by applying activation signals with different activation amplitudes all exceeding some minimal level. This suggests that the octopus arm could use minimal amplitudes of activation to generate the minimal muscle forces required for the production of the desired kinematics. Larger-amplitude signals would generate larger forces that increase the arm's stability against perturbations without changing the kinematic characteristics. The robustness of this phenomenon was demonstrated by examining activation signals with either a constant or a bell-shaped velocity profile. Our modeling suggests that the octopus arm biomechanics may allow independent control of kinematics and resistance to perturbation during arm extension movements.

Dual redundant arm system operational quality measures and their applications - Dynamic measures

NASA Technical Reports Server (NTRS)

Lee, Sukhan; Kim, Sungbok

1990-01-01

Dual-arm dynamic operation quality measures are presented which quantify the efficiency and capability of generating Cartesian accelerations by two cooperative arms based on the analysis of dual-arm dynamic interactions. Dual-arm dynamic manipulability is defined as the efficiency of generating Cartesian accelerations under the dynamic and kinematic interactions between individual arms and an object under manipulation. The analysis of dual-arm dynamic interactions is based on the so-called Cartesian space agent model of an arm, which represents an individual arm as a force source acting upon a point mass with the effective Cartesian space arm dynamics and an environment or an object under manipulation. The Cartesian space agent model of an arm makes it possible to derive the dynamic and kinematic constraints involved in the transport, assembly and grasping modes of dual-arm cooperation. A task-oriented operational quality measure, (TOQd) is defined by evaluating dual-arm dynamic manipulability in terms of given task requirements. TOQd is used in dual-arm joint configuration optimization. Simulation results are shown. A complete set of forward dynamic equations for a dual-arm system is derived, and dual-arm dynamic operational quality measures for various modes of dual-arm cooperation allowing sliding contacts are established.

Geo-additive modelling of malaria in Burundi

PubMed Central

2011-01-01

Background Malaria is a major public health issue in Burundi in terms of both morbidity and mortality, with around 2.5 million clinical cases and more than 15,000 deaths each year. It is still the single main cause of mortality in pregnant women and children below five years of age. Because of the severe health and economic burden of malaria, there is still a growing need for methods that will help to understand the influencing factors. Several studies/researches have been done on the subject yielding different results as which factors are most responsible for the increase in malaria transmission. This paper considers the modelling of the dependence of malaria cases on spatial determinants and climatic covariates including rainfall, temperature and humidity in Burundi. Methods The analysis carried out in this work exploits real monthly data collected in the area of Burundi over 12 years (1996-2007). Semi-parametric regression models are used. The spatial analysis is based on a geo-additive model using provinces as the geographic units of study. The spatial effect is split into structured (correlated) and unstructured (uncorrelated) components. Inference is fully Bayesian and uses Markov chain Monte Carlo techniques. The effects of the continuous covariates are modelled by cubic p-splines with 20 equidistant knots and second order random walk penalty. For the spatially correlated effect, Markov random field prior is chosen. The spatially uncorrelated effects are assumed to be i.i.d. Gaussian. The effects of climatic covariates and the effects of other spatial determinants are estimated simultaneously in a unified regression framework. Results The results obtained from the proposed model suggest that although malaria incidence in a given month is strongly positively associated with the minimum temperature of the previous months, regional patterns of malaria that are related to factors other than climatic variables have been identified, without being able to explain them. Conclusions In this paper, semiparametric models are used to model the effects of both climatic covariates and spatial effects on malaria distribution in Burundi. The results obtained from the proposed models suggest a strong positive association between malaria incidence in a given month and the minimum temperature of the previous month. From the spatial effects, important spatial patterns of malaria that are related to factors other than climatic variables are identified. Potential explanations (factors) could be related to socio-economic conditions, food shortage, limited access to health care service, precarious housing, promiscuity, poor hygienic conditions, limited access to drinking water, land use (rice paddies for example), displacement of the population (due to armed conflicts). PMID:21835010

Visitor’s Guide to Oliktok Point Atmospheric Radiation Measurement Climate Research Facility, North Slope of Alaska

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

Desilets, Darin; Helsel, Fred M.; Bendure, Al O.

2016-04-01

The importance of Oliktok Point, Alaska, as a focal point for climate research in the Arctic continues to grow with the addition of a U.S. Department of Energy (DOE) Atmospheric Radiation Monitoring (ARM) Climate Research Facility Mobile Facility (AMF) and the expansion of infrastructure to support airborne measurements. The site hosts a suite of instruments for making multi-year, high-fidelity atmospheric measurements; serves as a base of operations for field campaigns; and contains the only Restricted Airspace and Warning Area in the U.S. Arctic, which enables the use of unmanned aircraft systems. The use of this site by climate researchers involvesmore » several considerations, including its remoteness, harsh climate, and location amid the North Slope oilfields. This guide is intended to help visitors to Oliktok Point navigate this unique physical and administrative environment, and thereby facilitate safe and productive operations.« less

Modeling preferential water flow and solute transport in unsaturated soil using the active region model

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

Sheng, F.; Wang, K.; Zhang, R.

2009-03-15

Preferential flow and solute transport are common processes in the unsaturated soil, in which distributions of soil water content and solute concentrations are often characterized as fractal patterns. An active region model (ARM) was recently proposed to describe the preferential flow and transport patterns. In this study, ARM governing equations were derived to model the preferential soil water flow and solute transport processes. To evaluate the ARM equations, dye infiltration experiments were conducted, in which distributions of soil water content and Cl{sup -} concentration were measured. Predicted results using the ARM and the mobile-immobile region model (MIM) were compared withmore » the measured distributions of soil water content and Cl{sup -} concentration. Although both the ARM and the MIM are two-region models, they are fundamental different in terms of treatments of the flow region. The models were evaluated based on the modeling efficiency (ME). The MIM provided relatively poor prediction results of the preferential flow and transport with negative ME values or positive ME values less than 0.4. On the contrary, predicted distributions of soil water content and Cl- concentration using the ARM agreed reasonably well with the experimental data with ME values higher than 0.8. The results indicated that the ARM successfully captured the macroscopic behavior of preferential flow and solute transport in the unsaturated soil.« less

Experimental validation of flexible robot arm modeling and control

NASA Technical Reports Server (NTRS)

Ulsoy, A. Galip

1989-01-01

Flexibility is important for high speed, high precision operation of lightweight manipulators. Accurate dynamic modeling of flexible robot arms is needed. Previous work has mostly been based on linear elasticity with prescribed rigid body motions (i.e., no effect of flexible motion on rigid body motion). Little or no experimental validation of dynamic models for flexible arms is available. Experimental results are also limited for flexible arm control. Researchers include the effects of prismatic as well as revolute joints. They investigate the effect of full coupling between the rigid and flexible motions, and of axial shortening, and consider the control of flexible arms using only additional sensors.

Single-arm phase II trial design under parametric cure models.

PubMed

Wu, Jianrong

2015-01-01

The current practice of designing single-arm phase II survival trials is limited under the exponential model. Trial design under the exponential model may not be appropriate when a portion of patients are cured. There is no literature available for designing single-arm phase II trials under the parametric cure model. In this paper, a test statistic is proposed, and a sample size formula is derived for designing single-arm phase II trials under a class of parametric cure models. Extensive simulations showed that the proposed test and sample size formula perform very well under different scenarios. Copyright © 2015 John Wiley & Sons, Ltd.

Spatiotemporal integration for tactile localization during arm movements: a probabilistic approach.

PubMed

Maij, Femke; Wing, Alan M; Medendorp, W Pieter

2013-12-01

It has been shown that people make systematic errors in the localization of a brief tactile stimulus that is delivered to the index finger while they are making an arm movement. Here we modeled these spatial errors with a probabilistic approach, assuming that they follow from temporal uncertainty about the occurrence of the stimulus. In the model, this temporal uncertainty converts into a spatial likelihood about the external stimulus location, depending on arm velocity. We tested the prediction of the model that the localization errors depend on arm velocity. Participants (n = 8) were instructed to localize a tactile stimulus that was presented to their index finger while they were making either slow- or fast-targeted arm movements. Our results confirm the model's prediction that participants make larger localization errors when making faster arm movements. The model, which was used to fit the errors for both slow and fast arm movements simultaneously, accounted very well for all the characteristics of these data with temporal uncertainty in stimulus processing as the only free parameter. We conclude that spatial errors in dynamic tactile perception stem from the temporal precision with which tactile inputs are processed.

Modeling, design, and control of flexible manipulator arms: Status and trends

NASA Technical Reports Server (NTRS)

Book, Wayne J.

1989-01-01

The desire for higher performance manipulators has lead to dynamic behavior in which the flexibility is an essential aspect. The mathematical representations commonly used in modeling flexible arms and arms with flexible drives are examined first. Then design considerations directly arising from the flexible nature of the arm are discussed. Finally, controls of joints for general and tip motion are discussed.

A dynamic model for generating actuator specifications for small arms barrel active stabilization

NASA Astrophysics Data System (ADS)

Pathak, Anupam; Brei, Diann; Luntz, Jonathan; Lavigna, Chris

2006-03-01

Due to stresses encountered in combat, it is known that soldier marksmanship noticeably decreases regardless of prior training. Active stabilization systems in small arms have potential to address this problem to increase soldier survivability and mission effectiveness. The key to success is proper actuator design, but this is highly dependent on proper specification which is challenging due to the human/weapon interaction. This paper presents a generic analytical dynamic model which is capable of defining the necessary actuation specifications for a wide range of small arms platforms. The model is unique because it captures the human interface--shoulder and arm--that introduces the jitter disturbance in addition to the geometry, inertial properties and active stabilization stiffness of the small arms platform. Because no data to date is available for actual shooter-induced disturbance in field conditions, a method is given using the model to back-solve from measured shooting range variability data the disturbance amplitude information relative to the input source (arm or shoulder). As examples of the applicability of the model to various small arms systems, two different weapon systems were investigated: the M24 sniper weapon and the M16 assault rifle. In both cases, model based simulations provided valuable insight into impact on the actuation specifications (force, displacement, phase, frequency) due to the interplay of the human-weapon-active stabilization interface including the effect of shooter-disturbance frequency, disturbance location (shoulder vs. arm), and system parameters (stiffness, barrel rotation).

Dynamic model of the octopus arm. I. Biomechanics of the octopus reaching movement.

PubMed

Yekutieli, Yoram; Sagiv-Zohar, Roni; Aharonov, Ranit; Engel, Yaakov; Hochner, Binyamin; Flash, Tamar

2005-08-01

The octopus arm requires special motor control schemes because it consists almost entirely of muscles and lacks a rigid skeletal support. Here we present a 2D dynamic model of the octopus arm to explore possible strategies of movement control in this muscular hydrostat. The arm is modeled as a multisegment structure, each segment containing longitudinal and transverse muscles and maintaining a constant volume, a prominent feature of muscular hydrostats. The input to the model is the degree of activation of each of its muscles. The model includes the external forces of gravity, buoyancy, and water drag forces (experimentally estimated here). It also includes the internal forces generated by the arm muscles and the forces responsible for maintaining a constant volume. Using this dynamic model to investigate the octopus reaching movement and to explore the mechanisms of bend propagation that characterize this movement, we found the following. 1) A simple command producing a wave of muscle activation moving at a constant velocity is sufficient to replicate the natural reaching movements with similar kinematic features. 2) The biomechanical mechanism that produces the reaching movement is a stiffening wave of muscle contraction that pushes a bend forward along the arm. 3) The perpendicular drag coefficient for an octopus arm is nearly 50 times larger than the tangential drag coefficient. During a reaching movement, only a small portion of the arm is oriented perpendicular to the direction of movement, thus minimizing the drag force.

A Bird’s Eye View: Development of an Operational ARM Unmanned Aerial Capability for Atmospheric Research in Arctic Alaska

DOE PAGES

de Boer, Gijs; Ivey, Mark; Schmid, Beat; ...

2018-03-14

Here, we present that unmanned aerial capabilities offer exciting new perspectives on the Arctic atmosphere and the US Department of Energy is working with partners to offer such perspectives to the research community. Thorough understanding of aerosols, clouds, boundary layer structure and radiation is required to improve representation of the Arctic atmosphere in weather forecasting and climate models. To develop such understanding, new perspectives are needed to provide details on the vertical structure and spatial variability of key atmospheric properties, along with information over difficult-to-reach surfaces such as newly-forming sea ice. Over the last three years, the US Department ofmore » Energy (DOE) has supported various flight campaigns using unmanned aircraft systems (UAS, also known as UAVs and drones) and tethered balloon systems (TBS) at Oliktok Point, Alaska. These activities have featured in-situ measurements of thermodynamic state, turbulence, radiation, aerosol properties, cloud microphysics and turbulent fluxes to provide a detailed characterization of the lower atmosphere. Alongside a suite of active and passive ground-based sensors and radiosondes deployed by the DOE Atmospheric Radiation Measurement (ARM) program through the third ARM Mobile Facility (AMF-3), these flight activities demonstrate the ability of such platforms to provide critically-needed information. In addition to providing new and unique datasets, lessons learned during initial campaigns have assisted toward the development of an exciting new community resource.« less

A Bird’s Eye View: Development of an Operational ARM Unmanned Aerial Capability for Atmospheric Research in Arctic Alaska

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

de Boer, Gijs; Ivey, Mark; Schmid, Beat

Here, we present that unmanned aerial capabilities offer exciting new perspectives on the Arctic atmosphere and the US Department of Energy is working with partners to offer such perspectives to the research community. Thorough understanding of aerosols, clouds, boundary layer structure and radiation is required to improve representation of the Arctic atmosphere in weather forecasting and climate models. To develop such understanding, new perspectives are needed to provide details on the vertical structure and spatial variability of key atmospheric properties, along with information over difficult-to-reach surfaces such as newly-forming sea ice. Over the last three years, the US Department ofmore » Energy (DOE) has supported various flight campaigns using unmanned aircraft systems (UAS, also known as UAVs and drones) and tethered balloon systems (TBS) at Oliktok Point, Alaska. These activities have featured in-situ measurements of thermodynamic state, turbulence, radiation, aerosol properties, cloud microphysics and turbulent fluxes to provide a detailed characterization of the lower atmosphere. Alongside a suite of active and passive ground-based sensors and radiosondes deployed by the DOE Atmospheric Radiation Measurement (ARM) program through the third ARM Mobile Facility (AMF-3), these flight activities demonstrate the ability of such platforms to provide critically-needed information. In addition to providing new and unique datasets, lessons learned during initial campaigns have assisted toward the development of an exciting new community resource.« less

Hand-arm vibration exposure monitoring with wearable sensor module.

PubMed

Austad, Hanne O; Røed, Morten H; Liverud, Anders E; Dalgard, Steffen; Seeberg, Trine M

2013-01-01

Vibration exposure is a serious risk within work physiology for several work groups. Combined with cold artic climate, the risk for permanent harm is even higher. Equipment that can monitor the vibration exposure and warn the user when at risk will provide a safer work environment for these work groups. This study evaluates whether data from a wearable wireless multi-parameter sensor module can be used to estimate vibration exposure and exposure time. This work has been focused on the characterization of the response from the accelerometer in the sensor module and the optimal location of the module in the hand-arm configuration.

New velocimetry and revised cartography of the spiral arms in the Milky Way—a consistent symbiosis

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

Vallée, Jacques P., E-mail: jacques.vallee@cnrc.gc.ca

Recent advances in the determinations of the positions (pitch angle, shape, numbers, interarm separation) and velocities (rotation curve) of the spiral arms are evaluated and compared to previous determinations. Based on these results, an average cartographic model is developed that fits the means of basic input data and provides predictions for the locations of the arms in the Milky Way, for each galactic quadrant. For each spiral arm segment in each galactic quadrant, the LSR radial velocities are calculated for the radial distance as well as for its galactic longitude. From our velocimetric model, arm intercepts (between line of sightsmore » and spiral arms) are indicated in velocity space and may be used to find the distance and velocity to any arm, in a given longitude range. Velocity comparisons between model predictions and published CO velocity distribution are done for each galactic quadrant, with good results. Our velocimetric model is not hydromagnetic in character, nor is it a particle-simulation scheme, yet it is simple to use for comparisons with the observations and it is in symbiosis and consistent with our cartographic model (itself simple to use for comparisons with observations). A blending in velocity of the Perseus and Cygnus arms is further demonstrated, as well as an apparent longitude-velocity blending of the starting points of the four spiral arms near 4 kpc (not a physical ring). An integrated (distance, velocity) model for the mass in the disk is employed, to yield the total mass of 3.0 × 10{sup 11} M{sub ☉} within a galactic radius of 28 kpc.« less

Full-Time, Eye-Safe Cloud and Aerosol Lidar Observation at Atmospheric Radiation Measurement Program Sites: Instruments and Data Analysis

NASA Technical Reports Server (NTRS)

Campbell, James R.; Hlavka, Dennis L.; Welton, Ellsworth J.; Flynn, Connor J.; Turner, David D.; Spinhirne, James D.; Scott, V. Stanley, III; Hwang, I. H.; Einaudi, Franco (Technical Monitor)

2001-01-01

Atmospheric radiative forcing, surface radiation budget, and top of the atmosphere radiance interpretation involves a knowledge of the vertical height structure of overlying cloud and aerosol layers. During the last decade, the U.S. Department of Energy through I the Atmospheric Radiation Measurement (ARM) program has constructed four long- term atmospheric observing sites in strategic climate regimes (north central Oklahoma, In Barrow. Alaska, and Nauru and Manus Islands in the tropical western Pacific). Micro Pulse Lidar (MPL) systems provide continuous, autonomous observation of all significant atmospheric cloud and aerosol at each of the central ARM facilities. Systems are compact and transmitted pulses are eye-safe. Eye-safety is achieved by expanding relatively low-powered outgoing Pulse energy through a shared, coaxial transmit/receive telescope. ARM NIPL system specifications, and specific unit optical designs are discussed. Data normalization and calibration techniques are presented. A multiple cloud boundary detection algorithm is also described. These techniques in tandem represent an operational value added processing package used to produce normalized data products for Cloud and aerosol research and the historical ARM data archive.

Electron-capture Isotopes Could Constrain Cosmic-Ray Propagation Models

NASA Astrophysics Data System (ADS)

Benyamin, David; Shaviv, Nir J.; Piran, Tsvi

2017-12-01

Electron capture (EC) isotopes are known to provide constraints on the low-energy behavior of cosmic rays (CRs), such as reacceleration. Here, we study the EC isotopes within the framework of the dynamic spiral-arms CR propagation model in which most of the CR sources reside in the galactic spiral arms. The model was previously used to explain the B/C and sub-Fe/Fe ratios. We show that the known inconsistency between the 49Ti/49V and 51V/51Cr ratios remains also in the spiral-arms model. On the other hand, unlike the general wisdom that says the isotope ratios depend primarily on reacceleration, we find here that the ratio also depends on the halo size (Z h) and, in spiral-arms models, also on the time since the last spiral-arm passage ({τ }{arm}). Namely, EC isotopes can, in principle, provide interesting constraints on the diffusion geometry. However, with the present uncertainties in the lab measurements of both the electron attachment rate and the fragmentation cross sections, no meaningful constraint can be placed.

Mass extinctions, galactic orbits in the solar neighborhood and the Sun: a connection?

NASA Astrophysics Data System (ADS)

Porto de Mello, G. F.; Dias, W. S.; Lépine, J. R. D.; Lorenzo-Oliveira, D.; Siqueira, R. K.

2014-10-01

The orbits of the stars in the disk of the Galaxy, and their passages through the Galactic spiral arms, are a rarely mentioned factor of biosphere stability which might be important for long-term planetary climate evolution, with a possible bearing on mass extinctions. The Sun lies very near the co-rotation radius, where stars revolve around the Galaxy in the same period as the density wave perturbations of the spiral arms. Conventional wisdom generally considers that this status makes for few passages through the spiral arms. Controversy still surrounds whether time spent inside or around spiral arms is dangerous to biospheres and conducive to mass extinctions. Possible threats include giant molecular clouds disturbing the Oort comet cloud and provoking heavy bombardment; a higher exposure to cosmic rays near star forming regions triggering increased cloudiness in Earth's atmosphere and ice ages; and the destruction of Earth's ozone layer posed by supernova explosions. We present detailed calculations of the history of spiral arm passages for all 212 solar-type stars nearer than 20 parsecs, including the total time spent inside the spiral arms in the last 500 Myr, when the spiral arm position can be traced with good accuracy. We found that there is a large diversity of stellar orbits in the solar neighborhood, and the time fraction spent inside spiral arms can vary from a few percent to nearly half the time. The Sun, despite its proximity to the galactic co-rotation radius, has exceptionally low eccentricity and a low vertical velocity component, and therefore spends 30% of its lifetime crossing the spiral arms, more than most nearby stars. We discuss the possible implications of this fact to the long-term habitability of the Earth, and possible correlations of the Sun's passage through the spiral arms with the five great mass extinctions of the Earth's biosphere from the Late Ordovician to the Cretaceous-Tertiary.

Model-based sensorimotor integration for multi-joint control: development of a virtual arm model.

PubMed

Song, D; Lan, N; Loeb, G E; Gordon, J

2008-06-01

An integrated, sensorimotor virtual arm (VA) model has been developed and validated for simulation studies of control of human arm movements. Realistic anatomical features of shoulder, elbow and forearm joints were captured with a graphic modeling environment, SIMM. The model included 15 musculotendon elements acting at the shoulder, elbow and forearm. Muscle actions on joints were evaluated by SIMM generated moment arms that were matched to experimentally measured profiles. The Virtual Muscle (VM) model contained appropriate admixture of slow and fast twitch fibers with realistic physiological properties for force production. A realistic spindle model was embedded in each VM with inputs of fascicle length, gamma static (gamma(stat)) and dynamic (gamma(dyn)) controls and outputs of primary (I(a)) and secondary (II) afferents. A piecewise linear model of Golgi Tendon Organ (GTO) represented the ensemble sampling (I(b)) of the total muscle force at the tendon. All model components were integrated into a Simulink block using a special software tool. The complete VA model was validated with open-loop simulation at discrete hand positions within the full range of alpha and gamma drives to extrafusal and intrafusal muscle fibers. The model behaviors were consistent with a wide variety of physiological phenomena. Spindle afferents were effectively modulated by fusimotor drives and hand positions of the arm. These simulations validated the VA model as a computational tool for studying arm movement control. The VA model is available to researchers at website http://pt.usc.edu/cel .

Modal kinematics for multisection continuum arms.

PubMed

Godage, Isuru S; Medrano-Cerda, Gustavo A; Branson, David T; Guglielmino, Emanuele; Caldwell, Darwin G

2015-05-13

This paper presents a novel spatial kinematic model for multisection continuum arms based on mode shape functions (MSF). Modal methods have been used in many disciplines from finite element methods to structural analysis to approximate complex and nonlinear parametric variations with simple mathematical functions. Given certain constraints and required accuracy, this helps to simplify complex phenomena with numerically efficient implementations leading to fast computations. A successful application of the modal approximation techniques to develop a new modal kinematic model for general variable length multisection continuum arms is discussed. The proposed method solves the limitations associated with previous models and introduces a new approach for readily deriving exact, singularity-free and unique MSF's that simplifies the approach and avoids mode switching. The model is able to simulate spatial bending as well as straight arm motions (i.e., pure elongation/contraction), and introduces inverse position and orientation kinematics for multisection continuum arms. A kinematic decoupling feature, splitting position and orientation inverse kinematics is introduced. This type of decoupling has not been presented for these types of robotic arms before. The model also carefully accounts for physical constraints in the joint space to provide enhanced insight into practical mechanics and impose actuator mechanical limitations onto the kinematics thus generating fully realizable results. The proposed method is easily applicable to a broad spectrum of continuum arm designs.

Source tracing of thunderstorm generated inertia-gravity waves observed during the RADAGAST campaign in Niamey, Niger

NASA Astrophysics Data System (ADS)

Naren Athreyas, Kashyapa; Gunawan, Erry; Tay, Bee Kiat

2018-07-01

In recent years, the climate changes and weather have become a major concern which affects the daily life of a human being. Modelling and prediction of the complex atmospheric processes needs extensive theoretical studies and observational analyses to improve the accuracy of the prediction. The RADAGAST campaign was conducted by ARM climate research stationed at Niamey, Niger from January 2006 to January 2007, which was aimed to improve the west African climate studies have provided valuable data for research. In this paper, the characteristics and sources of inertia-gravity waves observed over Niamey during the campaign are investigated. The investigation focuses on highlighting the waves which are generated by thunderstorms which dominate the tropical region. The stratospheric energy densities spectrum is analysed for deriving the wave properties. The waves with Eulerian period from 20 to 50 h occupied most of the spectral power. It was found that the waves observed over Niamey had a dominant eastward propagation with horizontal wavelengths ranging from 350 to 1 400 km, and vertical wavelengths ranging from 0.9 to 3.6 km. GROGRAT model with ERA-Interim model data was used for establishing the background atmosphere to identify the source location of the waves. The waves generated by thunderstorms had propagation distances varying from 200 to 5 000 km and propagation duration from 2 to 4 days. The horizontal phase speeds varied from 2 to 20 m/s with wavelengths varying from 100 to 1 100 km, vertical phase speeds from 0.02 to 0.2 m/s and wavelengths from 2 to 15 km at the source point. The majority of sources were located in South Atlantic ocean and waves propagating towards northeast direction. This study demonstrated the complex large scale coupling in the atmosphere.

The Diurnal Cycle of Clouds and Precipitation at the ARM SGP Site: An Atmospheric State-Based Analysis and Error Decomposition of a Multiscale Modeling Framework Simulation

NASA Astrophysics Data System (ADS)

Zhao, Wei; Marchand, Roger; Fu, Qiang

2017-12-01

Long-term reflectivity data collected by a millimeter cloud radar at the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site are used to examine the diurnal cycle of clouds and precipitation and are compared with the diurnal cycle simulated by a Multiscale Modeling Framework (MMF) climate model. The study uses a set of atmospheric states that were created specifically for the SGP and for the purpose of investigating under what synoptic conditions models compare well with observations on a statistical basis (rather than using case studies or seasonal or longer time scale averaging). Differences in the annual mean diurnal cycle between observations and the MMF are decomposed into differences due to the relative frequency of states, the daily mean vertical profile of hydrometeor occurrence, and the (normalized) diurnal variation of hydrometeors in each state. Here the hydrometeors are classified as cloud or precipitation based solely on the reflectivity observed by a millimeter radar or generated by a radar simulator. The results show that the MMF does not capture the diurnal variation of low clouds well in any of the states but does a reasonable job capturing the diurnal variations of high clouds and precipitation in some states. In particular, the diurnal variations in states that occur during summer are reasonably captured by the MMF, while the diurnal variations in states that occur during the transition seasons (spring and fall) are not well captured. Overall, the errors in the annual composite are due primarily to errors in the daily mean of hydrometeor occurrence (rather than diurnal variations), but errors in the state frequency (that is, the distribution of weather states in the model) also play a significant role.

Improving and Understanding Climate Models: Scale-Aware Parameterization of Cloud Water Inhomogeneity and Sensitivity of MJO Simulation to Physical Parameters in a Convection Scheme

NASA Astrophysics Data System (ADS)

Xie, Xin

Microphysics and convection parameterizations are two key components in a climate model to simulate realistic climatology and variability of cloud distribution and the cycles of energy and water. When a model has varying grid size or simulations have to be run with different resolutions, scale-aware parameterization is desirable so that we do not have to tune model parameters tailored to a particular grid size. The subgrid variability of cloud hydrometers is known to impact microphysics processes in climate models and is found to highly depend on spatial scale. A scale- aware liquid cloud subgrid variability parameterization is derived and implemented in the Community Earth System Model (CESM) in this study using long-term radar-based ground measurements from the Atmospheric Radiation Measurement (ARM) program. When used in the default CESM1 with the finite-volume dynamic core where a constant liquid inhomogeneity parameter was assumed, the newly developed parameterization reduces the cloud inhomogeneity in high latitudes and increases it in low latitudes. This is due to both the smaller grid size in high latitudes, and larger grid size in low latitudes in the longitude-latitude grid setting of CESM as well as the variation of the stability of the atmosphere. The single column model and general circulation model (GCM) sensitivity experiments show that the new parameterization increases the cloud liquid water path in polar regions and decreases it in low latitudes. Current CESM1 simulation suffers from the bias of both the pacific double ITCZ precipitation and weak Madden-Julian oscillation (MJO). Previous studies show that convective parameterization with multiple plumes may have the capability to alleviate such biases in a more uniform and physical way. A multiple-plume mass flux convective parameterization is used in Community Atmospheric Model (CAM) to investigate the sensitivity of MJO simulations. We show that MJO simulation is sensitive to entrainment rate specification. We found that shallow plumes can generate and sustain the MJO propagation in the model.

Grand-design Spiral Arms in a Young Forming Circumstellar Disk

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

Tomida, Kengo; Lin, Chia Hui; Machida, Masahiro N.

We study formation and long-term evolution of a circumstellar disk in a collapsing molecular cloud core using a resistive magnetohydrodynamic simulation. While the formed circumstellar disk is initially small, it grows as accretion continues, and its radius becomes as large as 200 au toward the end of the Class-I phase. A pair of grand-design spiral arms form due to gravitational instability in the disk, and they transfer angular momentum in the highly resistive disk. Although the spiral arms disappear in a few rotations as expected in a classical theory, new spiral arms form recurrently as the disk, soon becoming unstablemore » again by gas accretion. Such recurrent spiral arms persist throughout the Class-0 and I phases. We then perform synthetic observations and compare our model with a recent high-resolution observation of a young stellar object Elias 2–27, whose circumstellar disk has grand-design spiral arms. We find good agreement between our theoretical model and the observation. Our model suggests that the grand-design spiral arms around Elias 2–27 are consistent with material arms formed by gravitational instability. If such spiral arms commonly exist in young circumstellar disks, it implies that young circumstellar disks are considerably massive and gravitational instability is the key process of angular momentum transport.« less

Using ARM Measurements to Understand and Reduce the Double ITCZ Biases in the Community Atmospheric Model

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

Zhang, Minghua

1. Understanding of the observed variability of ITCZ in the equatorial eastern Pacific. The annual mean precipitation in the eastern Pacific has a maximum zonal band north of the equator in the ITCZ where the maximum SST is located. During the boreal spring (referring to February, March, and April throughout the present paper), because of the accumulated solar radiation heating and oceanic heat transport, a secondary maximum of SST exists in the southeastern equatorial Pacific. Associated with this warm SST is also a seasonal transitional maximum of precipitation in the same region in boreal spring, exhibited as a weak doublemore » ITCZ pattern in the equatorial eastern Pacific. This climatological seasonal variation, however, varies greatly from year to year: double ITCZ in the boreal spring occurs in some years but not in other years; when there a single ITCZ, it can appear either north, south or at the equator. Understanding this observed variability is critical to find the ultimate cause of the double ITCZ in climate models. Seasonal variation of ITCZ south of the eastern equatorial Pacific: By analyzing data from satellites, field measurements and atmospheric reanalysis, we have found that in the region where spurious ITCZ in models occurs, there is a “seasonal cloud transition” — from stratocumulus to shallow cumulus and eventually to deep convection —in the South Equatorial Pacific (SEP) from September to April that is similar to the spatial cloud transition from the California coast to the equator. This seasonal transition is associated with increasing sea surface temperature (SST), decreasing lower tropospheric stability and large-scale subsidence. This finding of seasonal cloud transition points to the same source of model errors in the ITCZ simulations as in simulation of stratocumulus-cumulus-deep convection transition. It provides a test for climate models to simulate the relationships between clouds and large-scale atmospheric fields in a region that features a spurious double Inter-tropical Convergence Zone (ITCZ) in most models. This work is recently published in Yu et al. (2016). Interannual variation of ITCZ south of the eastern equatorial Pacific: By analyzing data from satellites, field measurements and atmospheric reanalysis, we have characterized the interannual variation of boreal spring precipitation in the eastern tropical Pacific and found the cause of the observed interannual variability. We have shown that ITCZ in this region can occur as a single ITCZ along the Equator, single ITCZ north of the Equator, single ITCZ south of the Equator, and double ITCZ on both sides of the Equator. We have found that convective instability only plays a secondary role in the ITCZ interannual variability. Instead, the remote impact of the Pacific basin-wide SST on the horizontal gradient of surface pressure and wind convergence is the primary driver of this interannual variability. Results point to the need to include moisture convergence in convection schemes to improve the simulation of precipitation in the eastern tropical Pacific. This result has been recently submitted for publication (Yu and Zhang 2016). 2. Improvement of model parameterizations to reduce the double ITCZ bias We analyzed the current status of climate model performance in simulating precipitation in the equatorial Pacific. We have found that the double ITCZ bias has not been reduced in CMIP5 models relative to CMIP4 models. We have characterized the dynamic structure of the common bias by using precipitation, sea surface temperature, surface winds and sea-level. Results are published in Zhang et al. (2015): Since cumulus convection plays a significant role in the double ITCZ behavior in models, we have used measurements from ARM and other sources to carry out a systematic analysis of the roles of shallow and deep convection in the CAM. We found that in both CAM4 and CAM5, when the intensity of deep convection decreases as a result of parameterization change, the intensity of shallow convection increases, leading to very different changes in precipitation partitions but little change in the total precipitation. The different precipitation partition however can manifest themselves in other measures of model performances including temperature and humidity. This study points to the need to treat model physical parameterizations as integrated system rather than individual components. Results from this study are published in Wang and Zhang (2013). Since shallow convection interacts with the deep convection scheme and surface turbulence to trigger the double ITCZ, we studied methods to improve the shallow convection scheme in climate models. We investigated the bulk budgets of the vertical velocity and its parameterization in convective cores, convective updrafts, and clouds by using large-eddy simulation (LES) of four shallow convection cases including one from ARM. We proposed optimal forms of the Simpson and Wiggert equation to calculate the vertical velocity in bulk mass flux convection schemes for convective cores, convective updrafts, and convective clouds as parameterization schemes. The new scheme is published in Wang and Zhang (2014). By using long-term radar-based ground measurements from ARM, we derived a scale-aware inhomogeneity parameterization of cloud liquid water in climate models. We found a relationship between the inhomogeneity parameter and the model grid size as well as atmospheric stability. This relationship is implemented in the CESM to describe the subgrid-scale cloud inhomogeneity. Relative to the default CESM with the finite-volume dynamic core at 2-degree resolution, the new parameterization leads to smaller cloud inhomogeneity and larger cloud liquid-water path in high latitudes, and the opposite effect in low latitudes, with the regional impact on shortwave cloud radiation effect of up to 10 W/m 2. This is due to both the smaller (larger) grid size in high (low) latitudes in the longitude-latitude grid setting of CESM and the more stable (unstable) atmosphere. This parameterization is expected lead to more realistic simulation of tropical precipitation in high-resolution models. Results from this study are reported in Xie and Zhang (2015).« less

Realities of War: Using Picture Books to Teach the Social Effects of Armed Conflicts

ERIC Educational Resources Information Center

Suzuki, Tadayuki; Huss, Jeanine; Fiehn, Barbara; Spencer, Roxanne Myers

2015-01-01

Teachers regularly evaluate children's literature for literary quality and age-appropriate information. Today's picture books address issues such as world population, homelessness, climate change, and other socially important themes, but when faced with social studies lessons on sensitive topics such as war and its reality, elementary teachers may…

Continuation of studies on thermoregulation of fish and turtles in thermally stressed habitats. Summary progress report, 1 October 1977-30 September 1980

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

Spotila, J.R.

1980-05-01

Biophysical-behavioral-ecological models have been completed to explain the behavioral thermoregulation of largemouth bass (Micropterus salmoides) and turtles (Chrysemys scripta). Steady state and time dependent mathematical models accurately predict the body temperatures of largemouth bass. Field experiments using multichannel radio transmitters have provided temperatures of several body compartments of free ranging bass in their natural habitat. Initial studies have been completed to describe the behavioral thermoregulation of bass in a reactor cooling reservoir. Energy budgets, fundamental climate spaces, and realized climate spaces have been completed for the turtle, C. scripta. We have described the behavioral thermoregulation of C. scripta in Parmore » Pond, S.C. and have measured its movements, home ranges and population levels in heated and unheated arms of the reservoir. Operative environmental temperature is a good predictor of the basking behavior of this turtle. A new synthesis explained the evolution of thermoregulatory strategies among animals. Laboratory experiments clarified the effects of movement, diving and temperature on the blood flow of alligators. Other experiments defined the role of boundary layers in controlling the evaporation of water from the surfaces of turtles and alligators in still and moving air. Nutritional status may be an important factor affecting the thermoregulatory behavior of turtles.« less

An innovative approach for modeling and simulation of an automated industrial robotic arm operated electro-pneumatically

NASA Astrophysics Data System (ADS)

Popa, L.; Popa, V.

2017-08-01

The article is focused on modeling an automated industrial robotic arm operated electro-pneumatically and to simulate the robotic arm operation. It is used the graphic language FBD (Function Block Diagram) to program the robotic arm on Zelio Logic automation. The innovative modeling and simulation procedures are considered specific problems regarding the development of a new type of technical products in the field of robotics. Thus, were identified new applications of a Programmable Logic Controller (PLC) as a specialized computer performing control functions with a variety of high levels of complexit.

THE B/C AND SUB-IRON/IRON COSMIC RAY RATIOS—FURTHER EVIDENCE IN FAVOR OF THE SPIRAL-ARM DIFFUSION MODEL

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

Benyamin, David; Piran, Tsvi; Shaviv, Nir J.

The boron to carbon (B/C) and sub-Fe/Fe ratios provide an important clue on cosmic ray (CR) propagation within the Galaxy. These ratios estimate the grammage that the CRs traverse as they propagate from their sources to Earth. Attempts to explain these ratios within the standard CR propagation models require ad hoc modifications and even with those these models necessitate inconsistent grammages to explain both ratios. As an alternative, physically motivated model, we have proposed that CRs originate preferably within the galactic spiral arms. CR propagation from dynamic spiral arms has important imprints on various secondary to primary ratios, such asmore » the B/C ratio and the positron fraction. We use our spiral-arm diffusion model with the spallation network extended up to nickel to calculate the sub-Fe/Fe ratio. We show that without any additional parameters the spiral-arm model consistently explains both ratios with the same grammage, providing further evidence in favor of this model.« less

Work environment and safety climate in the Swedish merchant fleet.

PubMed

Forsell, Karl; Eriksson, Helena; Järvholm, Bengt; Lundh, Monica; Andersson, Eva; Nilsson, Ralph

2017-02-01

To get knowledge of the work environment for seafarers sailing under the Swedish flag, in terms of safety climate, ergonomical, chemical and psychosocial exposures, and the seafarers self-rated health and work ability. A Web-based questionnaire was sent to all seafarers with a personal e-mail address in the Swedish Maritime Registry (N = 5608). Comparisons were made mainly within the study population, using Student's t test, prevalence odds ratios and logistic regressions with 95% confidence intervals. The response rate was 35% (N = 1972; 10% women, 90% men), with 61% of the respondents working on deck, 31% in the engine room and 7% in the catering/service department (1% not classifiable). Strain on neck, arm or back and heavy lifting were associated with female gender (p = 0.0001) and younger age (below or above 30 years of age, p < 0.0001). Exposures to exhausts, oils and dust were commonly reported. Major work problems were noise, risk of an accident and vibrations from the hull of the ship. The safety climate was high in comparison with that in land-based occupations. One-fourth had experienced personal harassment or bullying during last year of service. Noise, risk of accidents, hand/arm and whole-body vibrations and psychosocial factors such as harassment were commonly reported work environment problems among seafarers within the Swedish merchant fleet.

CHARACTERISTICS OF SPIRAL ARMS IN LATE-TYPE GALAXIES

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

Honig, Z. N.; Reid, M. J., E-mail: mreid@cfa.harvard.edu

2015-02-10

We have measured the positions of large numbers of H II regions in four nearly face-on, late-type, spiral galaxies: NGC 628 (M74), NGC 1232, NGC 3184, and NGC 5194 (M51). Fitting log-periodic spiral models to segments of each arm yields local estimates of spiral pitch angle and arm width. While pitch angles vary considerably along individual arms, among arms within a galaxy, and among galaxies, we find no systematic trend with galactocentric distance. We estimate the widths of the arm segments from the scatter in the distances of the H II regions from the spiral model. All major arms in these galaxies show spiralmore » arm width increasing with distance from the galactic center, similar to the trend seen in the Milky Way. However, in the outermost parts of the galaxies, where massive star formation declines, some arms reverse this trend and narrow. We find that spiral arms often appear to be composed of segments of ∼5 kpc length, which join to form kinks and abrupt changes in pitch angle and arm width; these characteristics are consistent with properties seen in the large N-body simulations of D'Onghia et al. and others.« less

The Development of the Speaker Independent ARM Continuous Speech Recognition System

DTIC Science & Technology

1992-01-01

spokeTi airborne reconnaissance reports u-ing a speech recognition system based on phoneme-level hidden Markov models (HMMs). Previous versions of the ARM...will involve automatic selection from multiple model sets, corresponding to different speaker types, and that the most rudimen- tary partition of a...The vocabulary size for the ARM task is 497 words. These words are related to the phoneme-level symbols corresponding to the models in the model set

Modal analysis and control of flexible manipulator arms. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Neto, O. M.

1974-01-01

The possibility of modeling and controlling flexible manipulator arms was examined. A modal approach was used for obtaining the mathematical model and control techniques. The arm model was represented mathematically by a state space description defined in terms of joint angles and mode amplitudes obtained from truncation on the distributed systems, and included the motion of a two link two joint arm. Three basic techniques were used for controlling the system: pole allocation with gains obtained from the rigid system with interjoint feedbacks, Simon-Mitter algorithm for pole allocation, and sensitivity analysis with respect to parameter variations. An improvement in arm bandwidth was obtained. Optimization of some geometric parameters was undertaken to maximize bandwidth for various payload sizes and programmed tasks. The controlled system is examined under constant gains and using the nonlinear model for simulations following a time varying state trajectory.

An agent-vector-host-environment model for controlling small arms and light weapons.

PubMed

Pinto, Andrew D; Sharma, Malika; Muggah, Robert

2011-05-01

Armed violence is a significant public health problem. It results in fatal and non-fatal injuries and disrupts social and economic processes that are essential to the health of individuals and communities. We argue that an agent-vector-host-environment model can be helpful in understanding and describing the availability and misuse of small arms and light weapons. Moreover, such a model can assist in identifying potential control points and in developing mitigation strategies. These concepts have been developed from analogous vector control programs and are applied to controlling arms to reduce their misuse. So-called 'denormalization' and 'de-legitimization' campaigns that focus on the vector - including the industry producing these commodities - can be based on the experience of public health in controlling tobacco use and exposure. This model can assist health professionals, civil society and governments in developing comprehensive strategies to limit the production, distribution and misuse of small arms and light weapons.

Final Technical Report for Grant # DE-FG02-06ER64169

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

Dr. Beat Schmid, PI

2007-07-13

The Atmospheric Radiation Measurement (ARM) program is funding this project to improve the methodology of ground-based remote sensing of the vertical distribution of aerosol and cloud optical properties, and their effect on atmospheric radiative transfer. Remotely-sensed and in situ observed aerosol, cloud physical, and optical properties collected during the May 2003 Aerosol Intensive Operational Period (AIOP) and the Aerosol Lidar Validation Experiment (ALIVE), conducted from September 11-22, 2005, are the basis for the investigation. We have used ground-based lidar, airborne sunphotometer and in situ measurements and other data to evaluate the vertical profile of aerosol properties. We have been pursuingmore » research in the following three areas: (1) Aerosol Best Estimate Product--Sensitivity Study: ARM is developing an Aerosol Best Estimate (ABE) Value Added Product (VAP) to provide aerosol optical properties at all times and heights above its sites. The ABE is used as input for the Broadband Heating Rate Profile (BBHRP) VAP, whose output will be used to evaluate the radiative treatment of aerosols and clouds in climate models. ARM has a need to assess how much detail is required for the ABE and if a useful ABE can be derived for the tropical and arctic climate research facilities (CRFs) where only limited aerosol information in the vertical is available. We have been determining the sensitivity of BBHRP to the vertical profile of aerosol optical properties used in ABE. (2) Vertically Resolved Aerosol and Cloud Radiative Properties over the Southern Great Plains (SGP): The AIOP delivered an unprecedented airborne radiometric and in situ data set related to aerosols and clouds. The Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS's) Twin Otter aircraft carried solar pointing, up- and down-looking radiometers (spectral and broadband, visible, and infrared) with the uplooking radiometers mounted on a stabilized platform. We are performing an integrated analysis of the largely unexploited radiometric data set to provide observation-based quantification of the effect of aerosols and clouds on the radiation field. We will link aerosol and cloud properties measured in situ with the observed radiative fluxes using radiative transfer models. This over-determined dataset will provide validation of the BBHRP VAP. (3) Integrated Analysis of Data from the Aerosol Lidar Validation Experiment: The ABE VAP relies on continuous lidar observations to provide the vertical distribution of the aerosols above the ARM sites. The goal of ALIVE, conducted in September 2005, was the validation of the aerosol extinction profiles obtained from the SGP Raman lidar, which has been recently refurbished/updated, and the Micro Pulse Lidar, for which a new algorithm to retrieve aerosol profiles has recently been developed, using the National Aeronautics and Space Administration (NASA) Ames Airborne Tracking 14 channel Sun photometer. We are performing and publishing the integrated analysis of the ALIVE data set.« less

Clinical and MRI activity as determinants of sample size for pediatric multiple sclerosis trials

PubMed Central

Verhey, Leonard H.; Signori, Alessio; Arnold, Douglas L.; Bar-Or, Amit; Sadovnick, A. Dessa; Marrie, Ruth Ann; Banwell, Brenda

2013-01-01

Objective: To estimate sample sizes for pediatric multiple sclerosis (MS) trials using new T2 lesion count, annualized relapse rate (ARR), and time to first relapse (TTFR) endpoints. Methods: Poisson and negative binomial models were fit to new T2 lesion and relapse count data, and negative binomial time-to-event and exponential models were fit to TTFR data of 42 children with MS enrolled in a national prospective cohort study. Simulations were performed by resampling from the best-fitting model of new T2 lesion count, number of relapses, or TTFR, under various assumptions of the effect size, trial duration, and model parameters. Results: Assuming a 50% reduction in new T2 lesions over 6 months, 90 patients/arm are required, whereas 165 patients/arm are required for a 40% treatment effect. Sample sizes for 2-year trials using relapse-related endpoints are lower than that for 1-year trials. For 2-year trials and a conservative assumption of overdispersion (ϑ), sample sizes range from 70 patients/arm (using ARR) to 105 patients/arm (TTFR) for a 50% reduction in relapses, and 230 patients/arm (ARR) to 365 patients/arm (TTFR) for a 30% relapse reduction. Assuming a less conservative ϑ, 2-year trials using ARR require 45 patients/arm (60 patients/arm for TTFR) for a 50% reduction in relapses and 145 patients/arm (200 patients/arm for TTFR) for a 30% reduction. Conclusion: Six-month phase II trials using new T2 lesion count as an endpoint are feasible in the pediatric MS population; however, trials powered on ARR or TTFR will need to be 2 years in duration and will require multicentered collaboration. PMID:23966255

Assessment of body composition in dialysis patients by arm bioimpedance compared to MRI and 40K measurements.

PubMed

Carter, M; Zhu, F; Kotanko, P; Kuhlmann, M; Ramirez, L; Heymsfield, S B; Handelman, G; Levin, N W

2009-01-01

This study used multi-frequency bioimpedance spectroscopy (BIS) of the arm and whole body to estimate muscle mass (MM) and subcutaneous adipose tissue (SAT) in 31 hemodialysis (HD) patients comparing these results with magnetic resonance imaging (MRI) and body potassium ((40)K) as gold standards. Total body and arm MM (MM(MRI)) and SAT (SAT(MRI)) were measured by MRI. All measurements were made before dialysis treatment. Regression models with the arm (aBIS) and whole body (wBIS) resistances were established. Correlations between gold standards and the BIS model were high for the arm SAT (r(2) = 0.93, standard error of estimate (SEE) = 3.6 kg), and whole body SAT (r(2) = 0.92, SEE = 3.5 kg), and for arm MM (r(2) = 0.84, SEE = 2.28 kg) and whole body MM (r(2) = 0.86, SEE = 2.28 kg). Total body MM and SAT can be accurately predicted by arm BIS models with advantages of convenience and portability, and it should be useful to assess nutritional status in HD patients. Copyright (c) 2009 S. Karger AG, Basel.

Galaxy Zoo: constraining the origin of spiral arms

NASA Astrophysics Data System (ADS)

Hart, Ross E.; Bamford, Steven P.; Keel, William C.; Kruk, Sandor J.; Masters, Karen L.; Simmons, Brooke D.; Smethurst, Rebecca J.

2018-07-01

Since the discovery that the majority of low-redshift galaxies exhibit some level of spiral structure, a number of theories have been proposed as to why these patterns exist. A popular explanation is a process known as swing amplification, yet there is no observational evidence to prove that such a mechanism is at play. By using a number of measured properties of galaxies, and scaling relations where there are no direct measurements, we model samples of SDSS and S4G spiral galaxies in terms of their relative halo, bulge, and disc mass and size. Using these models, we test predictions of swing amplification theory with respect to directly measured spiral arm numbers from Galaxy Zoo 2. We find that neither a universal cored nor cuspy inner dark matter profile can correctly predict observed numbers of arms in galaxies. However, by invoking a halo contraction/expansion model, a clear bimodality in the spiral galaxy population emerges. Approximately 40 per cent of unbarred spiral galaxies at z ≲ 0.1 and M* ≳ 1010 M⊙ have spiral arms that can be modelled by swing amplification. This population display a significant correlation between predicted and observed spiral arm numbers, evidence that they are swing amplified modes. The remainder are dominated by two-arm systems for which the model predicts significantly higher arm numbers. These are likely driven by tidal interactions or other mechanisms.

Galaxy Zoo: constraining the origin of spiral arms

NASA Astrophysics Data System (ADS)

Hart, Ross E.; Bamford, Steven P.; Keel, William C.; Kruk, Sandor J.; Masters, Karen L.; Simmons, Brooke D.; Smethurst, Rebecca J.

2018-05-01

Since the discovery that the majority of low-redshift galaxies exhibit some level of spiral structure, a number of theories have been proposed as to why these patterns exist. A popular explanation is a process known as swing amplification, yet there is no observational evidence to prove that such a mechanism is at play. By using a number of measured properties of galaxies, and scaling relations where there are no direct measurements, we model samples of SDSS and S4G spiral galaxies in terms of their relative halo, bulge and disc mass and size. Using these models, we test predictions of swing amplification theory with respect to directly measured spiral arm numbers from Galaxy Zoo 2. We find that neither a universal cored or cuspy inner dark matter profile can correctly predict observed numbers of arms in galaxies. However, by invoking a halo contraction/expansion model, a clear bimodality in the spiral galaxy population emerges. Approximately 40 per cent of unbarred spiral galaxies at z ≲ 0.1 and M* ≳ 1010M⊙ have spiral arms that can be modelled by swing amplification. This population display a significant correlation between predicted and observed spiral arm numbers, evidence that they are swing amplified modes. The remainder are dominated by two-arm systems for which the model predicts significantly higher arm numbers. These are likely driven by tidal interactions or other mechanisms.

Cloud, Aerosol, and Complex Terrain Interactions (CACTI) Preliminary Science Plan

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

Varble, Adam; Nesbitt, Steve; Salio, Paola

General circulation models and downscaled regional models exhibit persistent biases in deep convective initiation location and timing, cloud top height, stratiform area and precipitation fraction, and anvil coverage. Despite important impacts on the distribution of atmospheric heating, moistening, and momentum, nearly all climate models fail to represent convective organization, while system evolution is not represented at all. Improving representation of convective systems in models requires characterization of their predictability as a function of environmental conditions, and this characterization depends on observing many cases of convective initiation, non-initiation, organization, and non-organization. The Cloud, Aerosol, and Complex Terrain Interactions (CACTI) experiment inmore » the Sierras de Córdoba mountain range of north-central Argentina is designed to improve understanding of cloud life cycle and organization in relation to environmental conditions so that cumulus, microphysics, and aerosol parameterizations in multi-scale models can be improved. The Sierras de Córdoba range has a high frequency of orographic boundary-layer clouds, many reaching congestus depths, many initiating into deep convection, and some organizing into mesoscale systems uniquely observable from a single fixed site. Some systems even grow upscale to become among the deepest, largest, and longest-lived in the world. These systems likely contribute to an observed regional trend of increasing extreme rainfall, and poor prediction of them likely contributes to a warm, dry bias in climate models downstream of the Sierras de Córdoba range in a key agricultural region. Many environmental factors influence the convective lifecycle in this region including orographic, low-level jet, and frontal circulations, surface fluxes, synoptic vertical motions influenced by the Andes, cloud detrainment, and aerosol properties. Local and long-range transport of smoke resulting from biomass burning as well as blowing dust are common in the austral spring, while changes in land surface properties as the wet season progresses impact surface fluxes and boundary layer evolution on daily and seasonal time scales that feed back to cloud and rainfall generation. This range of environmental conditions and cloud properties coupled with a high frequency of events makes this an ideal location for improving our understanding of cloud-environment interactions. The following primary science questions will be addressed through coordinated first ARM Mobile Facility (AMF1), mobile C-band Scanning ARM Precipitation Radar (C-SAPR2), guest instrumentation, and potential ARM Aerial Facility (AAF) Gulfstream-1 (G-1) observations: 1. How are the properties and lifecycles of orographically generated cumulus humulis, mediocris, and congestus clouds affected by environmental kinematics, thermodynamics, aerosols, and surface properties? How do these cloud types alter these environmental conditions? 2. How do environmental kinematics, thermodynamics, and aerosols impact deep convective initiation, upscale growth, and mesoscale organization? How are soil moisture, surface fluxes, and aerosol properties altered by deep convective precipitation events and seasonal accumulation of precipitation? This multi-faceted experiment involves a long term 8.5-month Extended Observing Period (EOP, 15 August, 2018-30 April, 2019) as well as a 6-week Intensive Observation Period (IOP, 1 November-15 December) that will coincide with the international multi-agency RELAMPAGO field campaign.« less

Chromosome arm-specific BAC end sequences permit comparative analysis of homoeologous chromosomes and genomes of polyploid wheat

PubMed Central

2012-01-01

Background Bread wheat, one of the world’s staple food crops, has the largest, highly repetitive and polyploid genome among the cereal crops. The wheat genome holds the key to crop genetic improvement against challenges such as climate change, environmental degradation, and water scarcity. To unravel the complex wheat genome, the International Wheat Genome Sequencing Consortium (IWGSC) is pursuing a chromosome- and chromosome arm-based approach to physical mapping and sequencing. Here we report on the use of a BAC library made from flow-sorted telosomic chromosome 3A short arm (t3AS) for marker development and analysis of sequence composition and comparative evolution of homoeologous genomes of hexaploid wheat. Results The end-sequencing of 9,984 random BACs from a chromosome arm 3AS-specific library (TaaCsp3AShA) generated 11,014,359 bp of high quality sequence from 17,591 BAC-ends with an average length of 626 bp. The sequence represents 3.2% of t3AS with an average DNA sequence read every 19 kb. Overall, 79% of the sequence consisted of repetitive elements, 1.38% as coding regions (estimated 2,850 genes) and another 19% of unknown origin. Comparative sequence analysis suggested that 70-77% of the genes present in both 3A and 3B were syntenic with model species. Among the transposable elements, gypsy/sabrina (12.4%) was the most abundant repeat and was significantly more frequent in 3A compared to homoeologous chromosome 3B. Twenty novel repetitive sequences were also identified using de novo repeat identification. BESs were screened to identify simple sequence repeats (SSR) and transposable element junctions. A total of 1,057 SSRs were identified with a density of one per 10.4 kb, and 7,928 junctions between transposable elements (TE) and other sequences were identified with a density of one per 1.39 kb. With the objective of enhancing the marker density of chromosome 3AS, oligonucleotide primers were successfully designed from 758 SSRs and 695 Insertion Site Based Polymorphisms (ISBPs). Of the 96 ISBP primer pairs tested, 28 (29%) were 3A-specific and compared to 17 (18%) for 96 SSRs. Conclusion This work reports on the use of wheat chromosome arm 3AS-specific BAC library for the targeted generation of sequence data from a particular region of the huge genome of wheat. A large quantity of sequences were generated from the A genome of hexaploid wheat for comparative genome analysis with homoeologous B and D genomes and other model grass genomes. Hundreds of molecular markers were developed from the 3AS arm-specific sequences; these and other sequences will be useful in gene discovery and physical mapping. PMID:22559868

Action-based Dynamical Modeling for the Milky Way Disk: The Influence of Spiral Arms

NASA Astrophysics Data System (ADS)

Trick, Wilma H.; Bovy, Jo; D'Onghia, Elena; Rix, Hans-Walter

2017-04-01

RoadMapping is a dynamical modeling machinery developed to constrain the Milky Way’s (MW) gravitational potential by simultaneously fitting an axisymmetric parametrized potential and an action-based orbit distribution function (DF) to discrete 6D phase-space measurements of stars in the Galactic disk. In this work, we demonstrate RoadMapping's robustness in the presence of spiral arms by modeling data drawn from an N-body simulation snapshot of a disk-dominated galaxy of MW mass with strong spiral arms (but no bar), exploring survey volumes with radii 500 {pc}≤slant {r}\\max ≤slant 5 {kpc}. The potential constraints are very robust, even though we use a simple action-based DF, the quasi-isothermal DF. The best-fit RoadMapping model always recovers the correct gravitational forces where most of the stars that entered the analysis are located, even for small volumes. For data from large survey volumes, RoadMapping finds axisymmetric models that average well over the spiral arms. Unsurprisingly, the models are slightly biased by the excess of stars in the spiral arms. Gravitational potential models derived from survey volumes with at least {r}\\max =3 {kpc} can be reliably extrapolated to larger volumes. However, a large radial survey extent, {r}\\max ˜ 5 {kpc}, is needed to correctly recover the halo scale length. In general, the recovery and extrapolability of potentials inferred from data sets that were drawn from inter-arm regions appear to be better than those of data sets drawn from spiral arms. Our analysis implies that building axisymmetric models for the Galaxy with upcoming Gaia data will lead to sensible and robust approximations of the MW’s potential.

Numerical and experimental study of the 3D effect on connecting arm of vertical axis tidal current turbine

NASA Astrophysics Data System (ADS)

Guo, Wei; Kang, Hai-gui; Chen, Bing; Xie, Yu; Wang, Yin

2016-03-01

Vertical axis tidal current turbine is a promising device to extract energy from ocean current. One of the important components of the turbine is the connecting arm, which can bring about a significant effect on the pressure distribution along the span of the turbine blade, herein we call it 3D effect. However, so far the effect is rarely reported in the research, moreover, in numerical simulation. In the present study, a 3D numerical model of the turbine with the connecting arm was developed by using FLUENT software compiling the UDF (User Defined Function) command. The simulation results show that the pressure distribution along the span of blade with the connecting arm model is significantly different from those without the connecting arm. To facilitate the validation of numerical model, the laboratory experiment has been carried out by using three different types of NACA aerofoil connecting arm and circle section connecting arm. And results show that the turbine with NACA0012 connecting arm has the best start-up performance which is 0.346 m/s and the peak point of power conversion coefficient is around 0.33. A further study has been performed and a conclusion is drawn that the aerofoil and thickness of connecting arm are the most important factors on the power conversion coefficient of the vertical axis tidal current turbine.

Research on the Optimization Method of Arm Movement in the Assembly Workshop Based on Ergonomics

NASA Astrophysics Data System (ADS)

Hu, X. M.; Qu, H. W.; Xu, H. J.; Yang, L.; Yu, C. C.

2017-12-01

In order to improve the work efficiency and comfortability, Ergonomics is used to research the work of the operator in the assembly workshop. An optimization algorithm of arm movement in the assembly workshop is proposed. In the algorithm, a mathematical model of arm movement is established based on multi rigid body movement model and D-H method. The solution of inverse kinematics equation on arm movement is solved through kinematics theory. The evaluation functions of each joint movement and the whole arm movement are given based on the comfortability of human body joint. The solution method of the optimal arm movement posture based on the evaluation functions is described. The software CATIA is used to verify that the optimal arm movement posture is valid in an example and the experimental result show the effectiveness of the algorithm.

Analytic and simulation studies on the use of torque-wheel actuators for the control of flexible robotic arms

NASA Technical Reports Server (NTRS)

Montgomery, Raymond C.; Ghosh, Dave; Kenny, Sean

1991-01-01

This paper presents results of analytic and simulation studies to determine the effectiveness of torque-wheel actuators in suppressing the vibrations of two-link telerobotic arms with attached payloads. The simulations use a planar generic model of a two-link arm with a torque wheel at the free end. Parameters of the arm model are selected to be representative of a large space-based robotic arm of the same class as the Space Shuttle Remote Manipulator, whereas parameters of the torque wheel are selected to be similar to those of the Mini-Mast facility at the Langley Research Center. Results show that this class of torque-wheel can produce an oscillation of 2.5 cm peak-to-peak in the end point of the arm and that the wheel produces significantly less overshoot when the arm is issued an abrupt stop command from the telerobotic input station.

Model surgery with a passive robot arm for orthognathic surgery planning.

PubMed

Theodossy, Tamer; Bamber, Mohammad Anwar

2003-11-01

The aims of the study were to assess the degree of accuracy of model surgery performed manually using the Eastman technique and to compare it with model surgery performed with the aid of a robot arm. Twenty-one patients undergoing orthognathic surgery gave consent for this study. They were divided into 2 groups based on the model surgery technique used. Group A (52%) had model surgery performed manually, whereas group B (48%) had their model surgery performed using the robot arm. Patients' maxillary casts were measured before and after model surgery, and results were compared with those for the original treatment plan in horizontal (x-axis), vertical (y-axis), and transverse (z-axis) planes. Statistical analysis using Mann-Whitney U test for x- and y-axis and independent sample t test for z-axis have shown significant differences between both groups in x-axis (P =.024) and y-axis (P =.01) but not in z-axis (P =.776). Model surgery performed with the aid of a robot arm is significantly more accurate in anteroposterior and vertical planes than is manual model surgery. Robot arm has an important role to play in orthognathic surgery planning and in determining the biometrics of orthognathic surgical change at the model surgery stage.

Aerosol, cloud, and precipitation interactions in Eastern North Atlantic

NASA Astrophysics Data System (ADS)

Wang, J.; Wood, R.; Dong, X.

2017-12-01

With their extensive coverage, marine low clouds greatly impact global climate. Presently, marine low clouds are poorly represented in global climate models, and the response of marine low clouds to changes in atmospheric greenhouse gases and aerosols remains the major source of uncertainty in climate simulations. The Eastern North Atlantic (ENA) is a region of persistent but diverse subtropical marine boundary layer clouds, whose albedo and precipitation are highly susceptible to perturbations in aerosol properties. In addition, ENA is periodically impacted by anthropogenic aerosol both from North American and from continental Europe, making it an excellent location to study the CCN budget in a remote marine region periodically perturbed by anthropogenic emissions, and to investigate the impacts of long-range transport of aerosols on remote marine clouds. Aerosol and Cloud Experiments in Eastern North Atlantic (ACE-ENA), funded by DOE Atmospheric Radiation Measurement (ARM) program, is designed to improve the understanding of marine boundary CCN budget, cloud and drizzle microphysics, and the impact of aerosol on marine low cloud and precipitation in the ENA by combining airborne observations and long term surface based measurements. The study has two airborne deployments. The first deployment took place from June 15 to July 25, 2017, and the second one will take place from January 10 to February 20, 2018. Flights during the first deployment were carried out in the Azores, near the ARM ENA site on Graciosa Island. The long term measurements at the ENA site provide important Climatological context for the airborne observations during the two deployments, and the cloud structures provided by the scanning radars at the ENA site put the detailed in-situ measurements into mesoscale and cloud lifecycle contexts. Another important aspect of this study is to provide high quality in-situ measurements for validating and improving ground-based retrieval algorithms at the ENA site. This presentation will describe the setup and strategies of the study, early results from the first deployment on vertical structures and horizontal variabilities of aerosol properties, cloud and drizzle microphysics, and insights into the processes that drive the properties and interactions of aerosol and marine low clouds.

Veterans Advancing Clean Energy and Climate

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

Kopser, Joseph; Marr, Andrea; Perez-Halperin, Elizabeth

2013-11-11

The Champions of Change series highlights ordinary Americans who are doing extraordinary things in their communities to out-innovate, out-educate and out-build the rest of the world. On November 5, 2013, the White House honored 12 veterans and leaders who are using the skills they learned in the armed services to advance the clean energy economy.

Veterans Advancing Clean Energy and Climate

ScienceCinema

Kopser, Joseph; Marr, Andrea; Perez-Halperin, Elizabeth; Eckstein, Robin; Moniz, Ernest

2018-01-16

The Champions of Change series highlights ordinary Americans who are doing extraordinary things in their communities to out-innovate, out-educate and out-build the rest of the world. On November 5, 2013, the White House honored 12 veterans and leaders who are using the skills they learned in the armed services to advance the clean energy economy.

Impacts of Subgrid Heterogeneous Mixing between Cloud Liquid and Ice on the Wegner-Bergeron-Findeisen Process and Mixed-phase Clouds in NCAR CAM5

NASA Astrophysics Data System (ADS)

Liu, X.; Zhang, M.; Zhang, D.; Wang, Z.; Wang, Y.

2017-12-01

Mixed-phase clouds are persistently observed over the Arctic and the phase partitioning between cloud liquid and ice hydrometeors in mixed-phase clouds has important impacts on the surface energy budget and Arctic climate. In this study, we test the NCAR Community Atmosphere Model Version 5 (CAM5) with the single-column and weather forecast configurations and evaluate the model performance against observation data from the DOE Atmospheric Radiation Measurement (ARM) Program's M-PACE field campaign in October 2004 and long-term ground-based multi-sensor remote sensing measurements. Like most global climate models, we find that CAM5 also poorly simulates the phase partitioning in mixed-phase clouds by significantly underestimating the cloud liquid water content. Assuming pocket structures in the distribution of cloud liquid and ice in mixed-phase clouds as suggested by in situ observations provides a plausible solution to improve the model performance by reducing the Wegner-Bergeron-Findeisen (WBF) process rate. In this study, the modification of the WBF process in the CAM5 model has been achieved with applying a stochastic perturbation to the time scale of the WBF process relevant to both ice and snow to account for the heterogeneous mixture of cloud liquid and ice. Our results show that this modification of WBF process improves the modeled phase partitioning in the mixed-phase clouds. The seasonal variation of mixed-phase cloud properties is also better reproduced in the model in comparison with the long-term ground-based remote sensing observations. Furthermore, the phase partitioning is insensitive to the reassignment time step of perturbations.

Tethered Balloon Operations at ARM AMF3 Site at Oliktok Point, AK

NASA Astrophysics Data System (ADS)

Dexheimer, D.; Lucero, D. A.; Helsel, F.; Hardesty, J.; Ivey, M.

2015-12-01

Oliktok Point has been the home of the Atmospheric Radiation Measurement Program's (ARM) third ARM Mobile Facility, or AMF3, since October 2013. The AMF3 is operated through Sandia National Laboratories and hosts instrumentation collecting continuous measurements of clouds, aerosols, precipitation, energy, and other meteorological variables. The Arctic region is warming more quickly than any other region due to climate change and Arctic sea ice is declining to record lows. Sparsity of atmospheric data from the Arctic leads to uncertainty in process comprehension, and atmospheric general circulation models (AGCM) are understood to underestimate low cloud presence in the Arctic. Increased vertical resolution of meteorological properties and cloud measurements will improve process understanding and help AGCMs better characterize Arctic clouds. SNL is developing a tethered balloon system capable of regular operation at AMF3 in order to provide increased vertical resolution atmospheric data. The tethered balloon can be operated within clouds at altitudes up to 7,000' AGL within DOE's R-2204 restricted area. Pressure, relative humidity, temperature, wind speed, and wind direction are recorded at multiple altitudes along the tether. These data were validated against stationary met tower data in Albuquerque, NM. The altitudes of the sensors were determined by GPS and calculated using a line counter and clinometer and compared. Wireless wetness sensors and supercooled liquid water content sensors have also been deployed and their data has been compared with other sensors. This presentation will provide an overview of the balloons, sensors, and test flights flown, and will provide a preliminary look at data from sensor validation campaigns and test flights.

Spatial variability in land-atmosphere coupling strength at the ARM Southern Great Plains site under different cloud regimes

NASA Astrophysics Data System (ADS)

Tang, Q.; Xie, S.; Zhang, Y.

2016-12-01

The paucity of land/soil observations is a long-standing limitation for land-atmosphere (LA) coupling studies, in particular for estimating the spatial variability in the coupling strengths. Spatially dense atmospheric radiation measurement (ARM) sites deployed at the U.S. Southern Great Plains (SGP) covers a wide range of vegetation, surface, and soil types, and thus allow us to observe the spatial patterns of LA coupling. The upcoming "super site" at SGP will facilitate these studies at even finer scales. While many previous studies have focused only on the observations from the central facility (CF) site or the domain mean from multiple sites, in the present work we examine the robustness of many key surface and land observations (e.g., radiation, turbulence fluxes, soil moisture, etc.) at extended sites besides the CF site for a decade. The coupling strengths are estimated with temporal covariations between important variables. We subsample the data to different categories based on different cloud regimes (e.g., clear sky, shallow cumulus, and deep cumulus. These cloud regimes are strongly impacted by local factors. The spatial variability of coupling strengths at different ARM sites is assessed with respect to dominant drivers (i.e., vegetation, land type, etc.). The results of this study will provide insights for improving the representation of LA coupling in climate models by providing observational constraints to parameterizations, e.g., shallow convective schemes. This work is performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-698523

North Slope of Alaska Snow Intensive Operational Period Field Campaign Report

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

Verlinde, Johannes; Bartholomew, Mary Jane; Cherry, Jessica

The campaign was motivated by the need to improve the quantification of measurements of ice-phase precipitation in the Arctic and was by the acquisition and deployment of the new X- and Ka/W-band radars. These radars opened up an opportunity for the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility to obtain spatial estimates of snowfall rates using the polarimetric X-band measurements and dual-frequency measurements (using different combinations of the three wavelengths). However, calculations of X- and Ka-band radar back-scattering of ice crystal aggregates with their complex structure suggest that the commonly used T-matrix approach (Matrosov etmore » al. 2007) for modeling the radar back-scattering underestimates the reflectivity by several decibels, with errors increasing with increasing radar frequency (Botta et al. 2010, 2011). Moreover, the X-band polarimetric measurements and the Ka/W-band measurements are sensitive to the assumed shape of the snow (Botta et al. 2011). One of the five ARM two-dimensional video disdrometers (manufactured by Joanneum Research) were deployed in Barrow at the ARM North Slope of Alaska (NSA) site from 1 October, 2011 to 31 May, 2012 in an attempt to use the instrument in a novel way. The instrument was originally designed to measure the drop size distribution of rain but it seemed worthwhile to explore its capability to quantify ice precipitation particle size and shape distributions in the cold north for scattering calculations and precipitation estimations. Furthermore, this deployment gave us an opportunity to see how reliable it could be in arctic conditions.« less

The MVACS Robotic Arm Camera

NASA Astrophysics Data System (ADS)

Keller, H. U.; Hartwig, H.; Kramm, R.; Koschny, D.; Markiewicz, W. J.; Thomas, N.; Fernades, M.; Smith, P. H.; Reynolds, R.; Lemmon, M. T.; Weinberg, J.; Marcialis, R.; Tanner, R.; Boss, B. J.; Oquest, C.; Paige, D. A.

2001-08-01

The Robotic Arm Camera (RAC) is one of the key instruments newly developed for the Mars Volatiles and Climate Surveyor payload of the Mars Polar Lander. This lightweight instrument employs a front lens with variable focus range and takes images at distances from 11 mm (image scale 1:1) to infinity. Color images with a resolution of better than 50 μm can be obtained to characterize the Martian soil. Spectral information of nearby objects is retrieved through illumination with blue, green, and red lamp sets. The design and performance of the camera are described in relation to the science objectives and operation. The RAC uses the same CCD detector array as the Surface Stereo Imager and shares the readout electronics with this camera. The RAC is mounted at the wrist of the Robotic Arm and can characterize the contents of the scoop, the samples of soil fed to the Thermal Evolved Gas Analyzer, the Martian surface in the vicinity of the lander, and the interior of trenches dug out by the Robotic Arm. It can also be used to take panoramic images and to retrieve stereo information with an effective baseline surpassing that of the Surface Stereo Imager by about a factor of 3.

Predicting Directly Measured Trunk and Upper Arm Postures in Paper Mill Work From Administrative Data, Workers' Ratings and Posture Observations.

PubMed

Heiden, Marina; Garza, Jennifer; Trask, Catherine; Mathiassen, Svend Erik

2017-03-01

A cost-efficient approach for assessing working postures could be to build statistical models for predicting results of direct measurements from cheaper data, and apply these models to samples in which only the latter data are available. The present study aimed to build and assess the performance of statistical models predicting inclinometer-assessed trunk and arm posture among paper mill workers. Separate models were built using administrative data, workers' ratings of their exposure, and observations of the work from video recordings as predictors. Trunk and upper arm postures were measured using inclinometry on 28 paper mill workers during three work shifts each. Simultaneously, the workers were video filmed, and their postures were assessed by observation of the videos afterwards. Workers' ratings of exposure, and administrative data on staff and production during the shifts were also collected. Linear mixed models were fitted for predicting inclinometer-assessed exposure variables (median trunk and upper arm angle, proportion of time with neutral trunk and upper arm posture, and frequency of periods in neutral trunk and upper arm inclination) from administrative data, workers' ratings, and observations, respectively. Performance was evaluated in terms of Akaike information criterion, proportion of variance explained (R2), and standard error (SE) of the model estimate. For models performing well, validity was assessed by bootstrap resampling. Models based on administrative data performed poorly (R2 ≤ 15%) and would not be useful for assessing posture in this population. Models using workers' ratings of exposure performed slightly better (8% ≤ R2 ≤ 27% for trunk posture; 14% ≤ R2 ≤ 36% for arm posture). The best model was obtained when using observational data for predicting frequency of periods with neutral arm inclination. It explained 56% of the variance in the postural exposure, and its SE was 5.6. Bootstrap validation of this model showed similar expected performance in other samples (5th-95th percentile: R2 = 45-63%; SE = 5.1-6.2). Observational data had a better ability to predict inclinometer-assessed upper arm exposures than workers' ratings or administrative data. However, observational measurements are typically more expensive to obtain. The results encourage analyses of the cost-efficiency of modeling based on administrative data, workers' ratings, and observation, compared to the performance and cost of measuring exposure directly. © The Author 2017. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Mechanical Impedance Modeling of Human Arm: A survey

NASA Astrophysics Data System (ADS)

Puzi, A. Ahmad; Sidek, S. N.; Sado, F.

2017-03-01

Human arm mechanical impedance plays a vital role in describing motion ability of the upper limb. One of the impedance parameters is stiffness which is defined as the ratio of an applied force to the measured deformation of the muscle. The arm mechanical impedance modeling is useful in order to develop a better controller for system that interacts with human as such an automated robot-assisted platform for automated rehabilitation training. The aim of the survey is to summarize the existing mechanical impedance models of human upper limb so to justify the need to have an improved version of the arm model in order to facilitate the development of better controller of such systems with ever increase in complexity. In particular, the paper will address the following issue: Human motor control and motor learning, constant and variable impedance models, methods for measuring mechanical impedance and mechanical impedance modeling techniques.

Semiparametric Identification of Human Arm Dynamics for Flexible Control of a Functional Electrical Stimulation Neuroprosthesis

PubMed Central

Schearer, Eric M.; Liao, Yu-Wei; Perreault, Eric J.; Tresch, Matthew C.; Memberg, William D.; Kirsch, Robert F.; Lynch, Kevin M.

2016-01-01

We present a method to identify the dynamics of a human arm controlled by an implanted functional electrical stimulation neuroprosthesis. The method uses Gaussian process regression to predict shoulder and elbow torques given the shoulder and elbow joint positions and velocities and the electrical stimulation inputs to muscles. We compare the accuracy of torque predictions of nonparametric, semiparametric, and parametric model types. The most accurate of the three model types is a semiparametric Gaussian process model that combines the flexibility of a black box function approximator with the generalization power of a parameterized model. The semiparametric model predicted torques during stimulation of multiple muscles with errors less than 20% of the total muscle torque and passive torque needed to drive the arm. The identified model allows us to define an arbitrary reaching trajectory and approximately determine the muscle stimulations required to drive the arm along that trajectory. PMID:26955041

Soils as a Solution: The Potential of Rangelands to Contribute to Climate Change Mitigation

NASA Astrophysics Data System (ADS)

Silver, W. L.; Ryals, R.; DeLonge, M. S.; Owen, J. J.

2015-12-01

The majority of soil-related climate change research has focused on describing the problem - estimating rates of carbon (C) losses and greenhouse gas (GHG) emissions from natural and managed ecosystems. More research is needed to explore potential solutions to climate change through mitigation and adaptation. Here we report on an integrated set of studies aimed at critically evaluating the biogeochemical potential of rangeland soils to help mitigate climate change, while improving the sustainability and productivity of food production systems. We explored direct effects through enhanced net primary production (NPP) and soil C sequestration, and indirect effects through diversion of high emitting sources to lower emitting organic matter dynamics. We used a combination of long- and short-term field experiments, modeling, laboratory assays, life cycle assessment (LCA), and meta-analyses in consultation with a diverse group of stakeholders from both the private and public sectors. We found that organic matter amendments held particularly strong potential. Compost amendments increased soil C storage by 0.5-1.0 Mg C ha-1 y-1 in surface soils over 5 y, and increased NPP and water holding capacity. We measured 1.0 Mg of new C ha-1 y-1 over 3 y. Long-term amendment of cattle manure increased surface soil C by 19.0±7.3 Mg C ha-1 relative to unmanured fields. However, field and modeling experiments suggested that manure amendments lead to large nitrous oxide emissions that eventually eliminated CO2e benefits, whereas compost amendments continued to benefit climate for decades longer. An LCA identified a broader range of climate impacts. When scaled to an area of 25% of California's rangelands, new C sequestered following compost amendments (21 million Mg CO2e) exceeded emissions from cattle (15 million Mg CO2e); diverting organics from waste streams to amendments led to additional GHG savings. In collaboration with our partners, our research contributed to the development of a protocol for compost amendments, which is being used by stakeholders in C markets and by government agencies in climate action planning. In summary, we hope that our research and related activities will serve as a "call to arms" to the scientific community by highlighting a new and much needed arena for rigorous scientific research.

A method for removing arm backscatter from EPID images

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

King, Brian W.; Greer, Peter B.; School of Mathematical and Physical Sciences, University of Newcastle, Newcastle, New South Wales 2308

2013-07-15

Purpose: To develop a method for removing the support arm backscatter from images acquired using current Varian electronic portal imaging devices (EPIDs).Methods: The effect of arm backscatter on EPID images was modeled using a kernel convolution method. The parameters of the model were optimized by comparing on-arm images to off-arm images. The model was used to develop a method to remove the effect of backscatter from measured EPID images. The performance of the backscatter removal method was tested by comparing backscatter corrected on-arm images to measured off-arm images for 17 rectangular fields of different sizes and locations on the imager.more » The method was also tested using on- and off-arm images from 42 intensity modulated radiotherapy (IMRT) fields.Results: Images generated by the backscatter removal method gave consistently better agreement with off-arm images than images without backscatter correction. For the 17 rectangular fields studied, the root mean square difference of in-plane profiles compared to off-arm profiles was reduced from 1.19% (standard deviation 0.59%) on average without backscatter removal to 0.38% (standard deviation 0.18%) when using the backscatter removal method. When comparing to the off-arm images from the 42 IMRT fields, the mean {gamma} and percentage of pixels with {gamma} < 1 were improved by the backscatter removal method in all but one of the images studied. The mean {gamma} value (1%, 1 mm) for the IMRT fields studied was reduced from 0.80 to 0.57 by using the backscatter removal method, while the mean {gamma} pass rate was increased from 72.2% to 84.6%.Conclusions: A backscatter removal method has been developed to estimate the image acquired by the EPID without any arm backscatter from an image acquired in the presence of arm backscatter. The method has been shown to produce consistently reliable results for a wide range of field sizes and jaw configurations.« less

A 3D musculoskeletal model of the western lowland gorilla hind limb: moment arms and torque of the hip, knee and ankle.

PubMed

Goh, Colleen; Blanchard, Mary L; Crompton, Robin H; Gunther, Michael M; Macaulay, Sophie; Bates, Karl T

2017-10-01

Three-dimensional musculoskeletal models have become increasingly common for investigating muscle moment arms in studies of vertebrate locomotion. In this study we present the first musculoskeletal model of a western lowland gorilla hind limb. Moment arms of individual muscles around the hip, knee and ankle were compared with previously published data derived from the experimental tendon travel method. Considerable differences were found which we attribute to the different methodologies in this specific case. In this instance, we argue that our 3D model provides more accurate and reliable moment arm data than previously published data on the gorilla because our model incorporates more detailed consideration of the 3D geometry of muscles and the geometric constraints that exist on their lines-of-action about limb joints. Our new data have led us to revaluate the previous conclusion that muscle moment arms in the gorilla hind limb are optimised for locomotion with crouched or flexed limb postures. Furthermore, we found that bipedalism and terrestrial quadrupedalism coincided more regularly with higher moment arms and torque around the hip, knee and ankle than did vertical climbing. This indicates that the ability of a gorilla to walk bipedally is not restricted by musculoskeletal adaptations for quadrupedalism and vertical climbing, at least in terms of moment arms and torque about hind limb joints. © 2017 The Authors. Journal of Anatomy published by John Wiley & Sons Ltd on behalf of Anatomical Society.

Finger muscle attachments for an OpenSim upper-extremity model.

PubMed

Lee, Jong Hwa; Asakawa, Deanna S; Dennerlein, Jack T; Jindrich, Devin L

2015-01-01

We determined muscle attachment points for the index, middle, ring and little fingers in an OpenSim upper-extremity model. Attachment points were selected to match both experimentally measured locations and mechanical function (moment arms). Although experimental measurements of finger muscle attachments have been made, models differ from specimens in many respects such as bone segment ratio, joint kinematics and coordinate system. Likewise, moment arms are not available for all intrinsic finger muscles. Therefore, it was necessary to scale and translate muscle attachments from one experimental or model environment to another while preserving mechanical function. We used a two-step process. First, we estimated muscle function by calculating moment arms for all intrinsic and extrinsic muscles using the partial velocity method. Second, optimization using Simulated Annealing and Hooke-Jeeves algorithms found muscle-tendon paths that minimized root mean square (RMS) differences between experimental and modeled moment arms. The partial velocity method resulted in variance accounted for (VAF) between measured and calculated moment arms of 75.5% on average (range from 48.5% to 99.5%) for intrinsic and extrinsic index finger muscles where measured data were available. RMS error between experimental and optimized values was within one standard deviation (S.D) of measured moment arm (mean RMS error = 1.5 mm < measured S.D = 2.5 mm). Validation of both steps of the technique allowed for estimation of muscle attachment points for muscles whose moment arms have not been measured. Differences between modeled and experimentally measured muscle attachments, averaged over all finger joints, were less than 4.9 mm (within 7.1% of the average length of the muscle-tendon paths). The resulting non-proprietary musculoskeletal model of the human fingers could be useful for many applications, including better understanding of complex multi-touch and gestural movements.

Finger Muscle Attachments for an OpenSim Upper-Extremity Model

PubMed Central

Lee, Jong Hwa; Asakawa, Deanna S.; Dennerlein, Jack T.; Jindrich, Devin L.

2015-01-01

We determined muscle attachment points for the index, middle, ring and little fingers in an OpenSim upper-extremity model. Attachment points were selected to match both experimentally measured locations and mechanical function (moment arms). Although experimental measurements of finger muscle attachments have been made, models differ from specimens in many respects such as bone segment ratio, joint kinematics and coordinate system. Likewise, moment arms are not available for all intrinsic finger muscles. Therefore, it was necessary to scale and translate muscle attachments from one experimental or model environment to another while preserving mechanical function. We used a two-step process. First, we estimated muscle function by calculating moment arms for all intrinsic and extrinsic muscles using the partial velocity method. Second, optimization using Simulated Annealing and Hooke-Jeeves algorithms found muscle-tendon paths that minimized root mean square (RMS) differences between experimental and modeled moment arms. The partial velocity method resulted in variance accounted for (VAF) between measured and calculated moment arms of 75.5% on average (range from 48.5% to 99.5%) for intrinsic and extrinsic index finger muscles where measured data were available. RMS error between experimental and optimized values was within one standard deviation (S.D) of measured moment arm (mean RMS error = 1.5 mm < measured S.D = 2.5 mm). Validation of both steps of the technique allowed for estimation of muscle attachment points for muscles whose moment arms have not been measured. Differences between modeled and experimentally measured muscle attachments, averaged over all finger joints, were less than 4.9 mm (within 7.1% of the average length of the muscle-tendon paths). The resulting non-proprietary musculoskeletal model of the human fingers could be useful for many applications, including better understanding of complex multi-touch and gestural movements. PMID:25853869

Muscle short-range stiffness can be used to estimate the endpoint stiffness of the human arm

PubMed Central

Hu, Xiao; Murray, Wendy M.

2011-01-01

The mechanical properties of the human arm are regulated to maintain stability across many tasks. The static mechanics of the arm can be characterized by estimates of endpoint stiffness, considered especially relevant for the maintenance of posture. At a fixed posture, endpoint stiffness can be regulated by changes in muscle activation, but which activation-dependent muscle properties contribute to this global measure of limb mechanics remains unclear. We evaluated the role of muscle properties in the regulation of endpoint stiffness by incorporating scalable models of muscle stiffness into a three-dimensional musculoskeletal model of the human arm. Two classes of muscle models were tested: one characterizing short-range stiffness and two estimating stiffness from the slope of the force-length curve. All models were compared with previously collected experimental data describing how endpoint stiffness varies with changes in voluntary force. Importantly, muscle properties were not fit to the experimental data but scaled only by the geometry of individual muscles in the model. We found that force-dependent variations in endpoint stiffness were accurately described by the short-range stiffness of active arm muscles. Over the wide range of evaluated arm postures and voluntary forces, the musculoskeletal model incorporating short-range stiffness accounted for 98 ± 2, 91 ± 4, and 82 ± 12% of the variance in stiffness orientation, shape, and area, respectively, across all simulated subjects. In contrast, estimates based on muscle force-length curves were less accurate in all measures, especially stiffness area. These results suggest that muscle short-range stiffness is a major contributor to endpoint stiffness of the human arm. Furthermore, the developed model provides an important tool for assessing how the nervous system may regulate endpoint stiffness via changes in muscle activation. PMID:21289133

Helix-coil transition of a four-way DNA junction observed by multiple fluorescence parameters.

PubMed

Vámosi, György; Clegg, Robert M

2008-10-16

The thermal denaturation of immobile four-way DNA ("Holliday-") junctions with 17 base pair arms was studied via fluorescence spectroscopic measurements. Two arms of the molecule were labeled at the 5'-end with fluorescein and tetramethylrhodamine, respectively. Melting was monitored by the fluorescence intensity of the dyes, the fluorescence anisotropy of tetramethylrhodamine, and Forster resonance energy transfer (FRET) between fluorescein and rhodamine. To fit the thermal denaturation curves of the four-way junctions, two basic thermodynamic models were tested: (1) all-or-none transitions assuming a molecularity of one, two, or four and (2) a statistical "zipper" model. The all-or-none models correspond to reaction mechanisms assuming that the cooperative melting unit (that is, the structure changing from complete helix to complete coil) consists of (1) one arm, (2) two neighboring arms (which have one continuous strand common to the two arms), or (3) all four arms. In each case, the melting of the cooperative unit takes place in a single step. The tetramolecular reaction model (four-arm melting) yielded unrealistically low van't Hoff enthalpy and entropy values, whereas the monomolecular model (one-arm melting) resulted in a poor fit to the experimental data. The all-or-none bimolecular (two neighboring arm model) fit gave intermediate standard enthalpy change (Delta H) values between those expected for the melting of a duplex with a total length between the helix lengths of one and two arms (17 and 34 base pairs). Simulations according to the zipper model fit the experimental curves best when the length of the simulated duplex was assumed to be 34 base pairs, the length of a single strand. This suggests that the most important parameter determining the melting behavior of the molecule is the end-to-end distance of the strands (34 bases) rather than the length of the individual arms (17 base pairs) and that the equilibrium concentration of partially denatured intermediate states has to be taken into account. These findings are in good agreement with results obtained for three-way DNA junctions ( Stuhmeier, F. ; Lilley, D. M. ; Clegg, R. M. Biochemistry 1997, 36, 13539 ). An interesting result is that the extent-of-melting curves derived from the fluorescence intensity and anisotropy nearly agree, whereas the curve derived from the FRET data shows a change prior to the melting. This may be an indication of a conformational change leaving the double-stranded structure intact but changing the end-to-end distance of the different arms in a way consistent with the transition to the extended square configuration ( Clegg, R. M. ; Murchie, A. I. ; Lilley, D. M. Biophys. J. 1994, 66, 99 ) of this branched molecule.

Effect of reverse shoulder design philosophy on muscle moment arms.

PubMed

Hamilton, Matthew A; Diep, Phong; Roche, Chris; Flurin, Pierre Henri; Wright, Thomas W; Zuckerman, Joseph D; Routman, Howard

2015-04-01

This study analyzes the muscle moment arms of three different reverse shoulder design philosophies using a previously published method. Digital bone models of the shoulder were imported into a 3D modeling software and markers placed for the origin and insertion of relevant muscles. The anatomic model was used as a baseline for moment arm calculations. Subsequently, three different reverse shoulder designs were virtually implanted and moment arms were analyzed in abduction and external rotation. The results indicate that the lateral offset between the joint center and the axis of the humerus specific to one reverse shoulder design increased the external rotation moment arms of the posterior deltoid relative to the other reverse shoulder designs. The other muscles analyzed demonstrated differences in the moment arms, but none of the differences reached statistical significance. This study demonstrated how the combination of variables making up different reverse shoulder designs can affect the moment arms of the muscles in different and statistically significant ways. The role of humeral offset in reverse shoulder design has not been previously reported and could have an impact on external rotation and stability achieved post-operatively. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Recommendations for the Implementation of the LASSO Workflow

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

Gustafson, William I; Vogelmann, Andrew M; Cheng, Xiaoping

The U. S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Research Fa-cility began a pilot project in May 2015 to design a routine, high-resolution modeling capability to complement ARM’s extensive suite of measurements. This modeling capability, envisioned in the ARM Decadal Vision (U.S. Department of Energy 2014), subsequently has been named the Large-Eddy Simu-lation (LES) ARM Symbiotic Simulation and Observation (LASSO) project, and it has an initial focus of shallow convection at the ARM Southern Great Plains (SGP) atmospheric observatory. This report documents the recommendations resulting from the pilot project to be considered by ARM for imple-mentation into routinemore » operations. During the pilot phase, LASSO has evolved from the initial vision outlined in the pilot project white paper (Gustafson and Vogelmann 2015) to what is recommended in this report. Further details on the overall LASSO project are available at https://www.arm.gov/capabilities/modeling/lasso. Feedback regarding LASSO and the recommendations in this report can be directed to William Gustafson, the project principal investigator (PI), and Andrew Vogelmann, the co-principal investigator (Co-PI), via lasso@arm.gov.« less

Gaseous spiral structure and mass drift in spiral galaxies

NASA Astrophysics Data System (ADS)

Kim, Yonghwi; Kim, Woong-Tae

2014-05-01

We use hydrodynamic simulations to investigate non-linear gas responses to an imposed stellar spiral potential in disc galaxies. The gaseous medium is assumed to be infinitesimally thin, isothermal, and unmagnetized. We consider various spiral-arm models with differing strength and pattern speed. We find that the extent and shapes of gaseous arms as well as the related mass drift rate depend rather sensitively on the arm pattern speed. In models where the arm pattern is rotating slow, the gaseous arms extend across the corotation resonance (CR) all the way to the outer boundary, with a pitch angle slightly smaller than that of the stellar counterpart. In models with a fast rotating pattern, on the other hand, spiral shocks are much more tightly wound than the stellar arms, and cease to exist in the regions near and outside the CR where mathcal {M}_perp /sin p_* gtrsim 25-40, with mathcal {M}_perp denoting the perpendicular Mach number of a rotating gas relative to the arms with pitch angle p*. Inside the CR, the arms drive mass inflows at a rate of ˜0.05-3.0 M⊙ yr-1 to the central region, with larger values corresponding to stronger and slower arms. The contribution of the shock dissipation, external torque, and self-gravitational torque to the mass inflow is roughly 50, 40, and 10 per cent, respectively. We demonstrate that the distributions of line-of-sight velocities and spiral-arm densities can be a useful diagnostic tool to distinguish if the spiral pattern is rotating fast or slow.

Marine ARM GPCI Investigation of Clouds Bridge Display Field Campaign Report

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

Reynolds, R. Michael; Lewis, Ernie

2016-09-01

At the beginning of the U.S. Department of Energy (DOE) Marine Atmospheric Radiation Measurement (ARM) Climate Research Facility Global Energy and Water Experiment (GEWEX) Cloud System Study (GCSS) Pacific Cross-Section Intercomparison (GPCI) Investigation of Clouds (MAGIC) experiment, we recognized that the crew on the ship’s bridge would like to see a display of the meteorological data that was being collected. While a display on the bridge would be marginally useful to the science, it was decided to make a display for the bridge. A display was programmed in Lab View and a personal computer (PC) was set up in themore » bridge. This remained in operation until the ship went to dry dock for upgrades and service. Part of the upgrade was a new meteorological system for the ship. After this time there was no need for the ARM display and so it was not re-installed for the remainder of the program.« less

Modeling of two-hot-arm horizontal thermal actuator

NASA Astrophysics Data System (ADS)

Yan, Dong; Khajepour, Amir; Mansour, Raafat

2003-03-01

Electrothermal actuators have a very promising future in MEMS applications since they can generate large deflection and force with low actuating voltages and small device areas. In this study, a lumped model of a two-hot-arm horizontal thermal actuator is presented. In order to prove the accuracy of the lumped model, finite element analysis (FEA) and experimental results are provided. The two-hot-arm thermal actuator has been fabricated using the MUMPs process. Both the experimental and FEA results are in good agreement with the results of lumped modeling.

Stellar orbits in the Galaxy and mass extinctions on the Earth: a connection?

NASA Astrophysics Data System (ADS)

Porto de Mello, G. F.; Dias, W. S.; Lepine, J.; Lorenzo-Oliveira, D.; Kazu, R. S.

2014-03-01

The orbits of the stars in the disk of the Galaxy, and their passages through the Galactic spiral arms, are a rarely mentioned factor of biosphere stability which might be important for long-term planetary climate evolution, with a possible bearing on mass extinctions. The Sun lies very near the co-rotation radius, where stars revolve around the Galaxy in the same period as the density wave perturbations of the spiral arms (Dias & Lepine 2005). Conventional wisdom generally considers that this status makes for few passages through the spiral arms. Controversy still surrounds whether time spent inside or around spiral arms is dangerous to biospheres and conducive to mass extinctions (Bailer-Jones 2009). Possible threats include giant molecular clouds disturbing the Oort comet cloud and provoking heavy bombardment (Clube & Napier 1982); a higher exposure to cosmic rays near star forming regions triggering increased cloudiness in Earth's atmosphere and ice ages (Gies & Helsel 2005); and the destruction of Earth's ozone layer posed by supernova explosions (Gehrels et al 2003). We present detailed calculations of the history of spiral arm passages for all 212 solartype stars nearer than 20 parsecs, including the total time spent inside the spiral arms in the last 500 million years, when the spiral arm position can be traced with good accuracy. There is a very large diversity of stellar orbits amongst solar neighborhood solar-type stars, and the time fraction spent inside spiral arms can vary from a few percent to nearly half the time. The Sun, despite its proximity to the galactic co-rotation radius, has exceptionally low eccentricity and a low vertical velocity component, and therefore spends 40% of its lifetime crossing the spiral arms, more than nearly all nearby stars. We discuss the possible implications of this fact to the long-term habitability of the Earth, and possible correlations of the Sun's passage through the spiral arms with the five great mass extinctions of the Earth's biosphere from the Late Ordovician to the Cretaceous-Tertiary.

Clouds, Aerosol, and Precipitation in the Marine Boundary Layer: An ARM Mobile Facility Deployment

NASA Technical Reports Server (NTRS)

Wood, Robert; Wyant, Matthew; Bretherton, Christopher S.; Remillard, Jasmine; Kollias, Pavlos; Fletcher, Jennifer; Stemmler, Jayson; de Szoeke, Simone; Yuter, Sandra; Miller, Matthew;

Three-dimensional constrained variational analysis: Approach and application to analysis of atmospheric diabatic heating and derivative fields during an ARM SGP intensive observational period

NASA Astrophysics Data System (ADS)

Tang, Shuaiqi; Zhang, Minghua

2015-08-01

Atmospheric vertical velocities and advective tendencies are essential large-scale forcing data to drive single-column models (SCMs), cloud-resolving models (CRMs), and large-eddy simulations (LESs). However, they cannot be directly measured from field measurements or easily calculated with great accuracy. In the Atmospheric Radiation Measurement Program (ARM), a constrained variational algorithm (1-D constrained variational analysis (1DCVA)) has been used to derive large-scale forcing data over a sounding network domain with the aid of flux measurements at the surface and top of the atmosphere (TOA). The 1DCVA algorithm is now extended into three dimensions (3DCVA) along with other improvements to calculate gridded large-scale forcing data, diabatic heating sources (Q1), and moisture sinks (Q2). Results are presented for a midlatitude cyclone case study on 3 March 2000 at the ARM Southern Great Plains site. These results are used to evaluate the diabatic heating fields in the available products such as Rapid Update Cycle, ERA-Interim, National Centers for Environmental Prediction Climate Forecast System Reanalysis, Modern-Era Retrospective Analysis for Research and Applications, Japanese 55-year Reanalysis, and North American Regional Reanalysis. We show that although the analysis/reanalysis generally captures the atmospheric state of the cyclone, their biases in the derivative terms (Q1 and Q2) at regional scale of a few hundred kilometers are large and all analyses/reanalyses tend to underestimate the subgrid-scale upward transport of moist static energy in the lower troposphere. The 3DCVA-gridded large-scale forcing data are physically consistent with the spatial distribution of surface and TOA measurements of radiation, precipitation, latent and sensible heat fluxes, and clouds that are better suited to force SCMs, CRMs, and LESs. Possible applications of the 3DCVA are discussed.

Using ARM Observations to Evaluate Climate Model Representation of Land-Atmosphere Coupling on the U.S. Southern Great Plains

NASA Astrophysics Data System (ADS)

Phillips, T. J.; Klein, S. A.; Ma, H. Y.; Tang, Q.

2016-12-01

Statistically significant coupling between summertime soil moisture and various atmospheric variables has been observed at the U.S. Southern Great Plains (SGP) facilities maintained by the U.S. DOE Atmospheric Radiation Measurement (ARM) program (Phillips and Klein, 2014 JGR). In the current study, we employ several independent measurements of shallow-depth soil moisture (SM) and of the surface evaporative fraction (EF) over multiple summers in order to estimate the range of SM-EF coupling strength at seven sites, and to approximate the SGP regional-scale coupling strength (and its uncertainty). We will use this estimate of regional-scale SM-EF coupling strength to evaluate its representation in version 5.1 of the global Community Atmosphere Model (CAM5.1) coupled to the CLM4 Land Model. Two experimental cases are considered for the 2003-2011 study period: 1) an Atmospheric Model Intercomparison Project (AMIP) run with historically observed sea surface temperatures specified, and 2) a more constrained hindcast run in which the CAM5.1 atmospheric state is initialized each day from the ERA Interim reanalysis, while the CLM4 initial conditions are obtained from an offline run of the land model using observed surface net radiation, precipitation, and wind as forcings. These twin experimental cases allow a distinction to be drawn between the land-atmosphere coupling in the free-running CAM5.1/CLM4 model and that in which the land and atmospheric states are constrained to remain closer to "reality". The constrained hindcast case, for example, should allow model errors in coupling strength to be related more closely to potential deficiencies in land-surface or atmospheric boundary-layer parameterizations. AcknowledgmentsThis work was funded by the U.S. Department of Energy Office of Science and was performed at the Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

RACORO continental boundary layer cloud investigations. 2. Large-eddy simulations of cumulus clouds and evaluation with in-situ and ground-based observations

DOE PAGES

Endo, Satoshi; Fridlind, Ann M.; Lin, Wuyin; ...

2015-06-19

A 60-hour case study of continental boundary layer cumulus clouds is examined using two large-eddy simulation (LES) models. The case is based on observations obtained during the RACORO Campaign (Routine Atmospheric Radiation Measurement [ARM] Aerial Facility [AAF] Clouds with Low Optical Water Depths [CLOWD] Optical Radiative Observations) at the ARM Climate Research Facility's Southern Great Plains site. The LES models are driven by continuous large-scale and surface forcings, and are constrained by multi-modal and temporally varying aerosol number size distribution profiles derived from aircraft observations. We compare simulated cloud macrophysical and microphysical properties with ground-based remote sensing and aircraft observations.more » The LES simulations capture the observed transitions of the evolving cumulus-topped boundary layers during the three daytime periods, and generally reproduce variations of droplet number concentration with liquid water content (LWC), corresponding to the gradient between the cloud centers and cloud edges at given heights. The observed LWC values fall within the range of simulated values; the observed droplet number concentrations are commonly higher than simulated, but differences remain on par with potential estimation errors in the aircraft measurements. Sensitivity studies examine the influences of bin microphysics versus bulk microphysics, aerosol advection, supersaturation treatment, and aerosol hygroscopicity. Simulated macrophysical cloud properties are found to be insensitive in this non-precipitating case, but microphysical properties are especially sensitive to bulk microphysics supersaturation treatment and aerosol hygroscopicity.« less

Shallow Cumulus Variability at the ARM Eastern North Atlantic Site

NASA Astrophysics Data System (ADS)

Lamer, K.; Kollias, P.; Ghate, V. P.; Luke, E. P.

2016-12-01

Cumulus clouds play a critical role in modulating the radiative and hydrological budget of the lower troposphere. These clouds, which are ubiquitous in regions of large-scale subsidence over the oceans, tend to be misrepresented in global climate models. Island-based, long-term, high-resolution ground-based observations can provide valuable insights on the factors controlling their macroscopic and microphysical properties and subsequenlty assist in model evaluation and guidance. Previous studies, limited to fair-weather cumuli over land, revealed that their fractional coverage is only weakly correlated with several parameters; the best ones being complex dynamical characteristics of the subcloud layer (vertical velocity skewness and eddy coherence). Other studies noted a relationship between cumuli depth and their propensity to precipitate. The current study will expand on such analysis by performing detail characterization of the full spectrum of shallow cumulus fields from non-precipitating to precipitating in the context of the large-scale forcing (i.e. thermodynamic structure and subsidence rates). Two years of ground-based remote sensing observations collected at the Atmospheric Radiation Measurement (ARM) Eastern North Atlantic (ENA) site are used to document macroscopic (cloud depth, cord length, cover), microphysical (liquid water path, cloud base rain rate) and dynamical (cloud base mass flux, eddy dissipation rate) cumuli properties. The observed variability in shallow cumulus is examined in relation to the variability of the large-scale environment as captured by the humidity profile, the magnitude of the low-level horizontal winds and near-surface aerosol conditions.

A path towards uncertainty assignment in an operational cloud-phase algorithm from ARM vertically pointing active sensors

DOE PAGES

Riihimaki, Laura D.; Comstock, Jennifer M.; Anderson, Kevin K.; ...

2016-06-10

Knowledge of cloud phase (liquid, ice, mixed, etc.) is necessary to describe the radiative impact of clouds and their lifetimes, but is a property that is difficult to simulate correctly in climate models. One step towards improving those simulations is to make observations of cloud phase with sufficient accuracy to help constrain model representations of cloud processes. In this study, we outline a methodology using a basic Bayesian classifier to estimate the probabilities of cloud-phase class from Atmospheric Radiation Measurement (ARM) vertically pointing active remote sensors. The advantage of this method over previous ones is that it provides uncertainty informationmore » on the phase classification. We also test the value of including higher moments of the cloud radar Doppler spectrum than are traditionally used operationally. Using training data of known phase from the Mixed-Phase Arctic Cloud Experiment (M-PACE) field campaign, we demonstrate a proof of concept for how the method can be used to train an algorithm that identifies ice, liquid, mixed phase, and snow. Over 95 % of data are identified correctly for pure ice and liquid cases used in this study. Mixed-phase and snow cases are more problematic to identify correctly. When lidar data are not available, including additional information from the Doppler spectrum provides substantial improvement to the algorithm. As a result, this is a first step towards an operational algorithm and can be expanded to include additional categories such as drizzle with additional training data.« less

A path towards uncertainty assignment in an operational cloud-phase algorithm from ARM vertically pointing active sensors

NASA Astrophysics Data System (ADS)

Riihimaki, Laura D.; Comstock, Jennifer M.; Anderson, Kevin K.; Holmes, Aimee; Luke, Edward

2016-06-01

Knowledge of cloud phase (liquid, ice, mixed, etc.) is necessary to describe the radiative impact of clouds and their lifetimes, but is a property that is difficult to simulate correctly in climate models. One step towards improving those simulations is to make observations of cloud phase with sufficient accuracy to help constrain model representations of cloud processes. In this study, we outline a methodology using a basic Bayesian classifier to estimate the probabilities of cloud-phase class from Atmospheric Radiation Measurement (ARM) vertically pointing active remote sensors. The advantage of this method over previous ones is that it provides uncertainty information on the phase classification. We also test the value of including higher moments of the cloud radar Doppler spectrum than are traditionally used operationally. Using training data of known phase from the Mixed-Phase Arctic Cloud Experiment (M-PACE) field campaign, we demonstrate a proof of concept for how the method can be used to train an algorithm that identifies ice, liquid, mixed phase, and snow. Over 95 % of data are identified correctly for pure ice and liquid cases used in this study. Mixed-phase and snow cases are more problematic to identify correctly. When lidar data are not available, including additional information from the Doppler spectrum provides substantial improvement to the algorithm. This is a first step towards an operational algorithm and can be expanded to include additional categories such as drizzle with additional training data.

Improved orthopedic arm joint

NASA Technical Reports Server (NTRS)

Dane, D. H.

1971-01-01

Joint permits smooth and easy movement of disabled arm and is smaller, lighter and less expensive than previous models. Device is interchangeable and may be used on either arm at the shoulder or at the elbow.

Stochastic estimation of human arm impedance under nonlinear friction in robot joints: a model study.

PubMed

Chang, Pyung Hun; Kang, Sang Hoon

2010-05-30

The basic assumption of stochastic human arm impedance estimation methods is that the human arm and robot behave linearly for small perturbations. In the present work, we have identified the degree of influence of nonlinear friction in robot joints to the stochastic human arm impedance estimation. Internal model based impedance control (IMBIC) is then proposed as a means to make the estimation accurate by compensating for the nonlinear friction. From simulations with a nonlinear Lugre friction model, it is observed that the reliability and accuracy of the estimation are severely degraded with nonlinear friction: below 2 Hz, multiple and partial coherence functions are far less than unity; estimated magnitudes and phases are severely deviated from that of a real human arm throughout the frequency range of interest; and the accuracy is not enhanced with an increase of magnitude of the force perturbations. In contrast, the combined use of stochastic estimation and IMBIC provides with accurate estimation results even with large friction: the multiple coherence functions are larger than 0.9 throughout the frequency range of interest and the estimated magnitudes and phases are well matched with that of a real human arm. Furthermore, the performance of suggested method is independent of human arm and robot posture, and human arm impedance. Therefore, the IMBIC will be useful in measuring human arm impedance with conventional robot, as well as in designing a spatial impedance measuring robot, which requires gearing. (c) 2010 Elsevier B.V. All rights reserved.

A robot arm simulation with a shared memory multiprocessor machine

NASA Technical Reports Server (NTRS)

Kim, Sung-Soo; Chuang, Li-Ping

1989-01-01

A parallel processing scheme for a single chain robot arm is presented for high speed computation on a shared memory multiprocessor. A recursive formulation that is derived from a virtual work form of the d'Alembert equations of motion is utilized for robot arm dynamics. A joint drive system that consists of a motor rotor and gears is included in the arm dynamics model, in order to take into account gyroscopic effects due to the spinning of the rotor. The fine grain parallelism of mechanical and control subsystem models is exploited, based on independent computation associated with bodies, joint drive systems, and controllers. Efficiency and effectiveness of the parallel scheme are demonstrated through simulations of a telerobotic manipulator arm. Two different mechanical subsystem models, i.e., with and without gyroscopic effects, are compared, to show the trade-off between efficiency and accuracy.

East Asian Studies of Tropospheric Aerosols and their Impact on Regional Climate (EAST -AIRC): An overview

NASA Technical Reports Server (NTRS)

Zhangqing, Li; Li, C.; Chen, H.; Tsay, S.-C.; Holben, B.; Huang, J.; Li, B.; Maring, H.; Qian, Y.; Shi, G.;

Investigating the Sustainability of Perennial Agriculture

NASA Astrophysics Data System (ADS)

Sutherlin, C. E.; Brunsell, N. A.; De Oliveira, G.; Crews, T.; Vico, G.

2017-12-01

The changing climate leads to uncertainties concerning the sustainability of certain agricultural resources, and with the additional stresses of an increasing global population, uncertainty in food security will greatly increase. To adhere to future food demands in the face of this changing climate, perennial agriculture has been a proposed solution. However, it is equally important to assure that perennial agriculture is not negatively affecting the climate in exchange for this proposed more robust food source. We chose to examine the interactions between perennial and annual agricultural crops by focusing on the efficiency of exchanges with the atmosphere. This is done using the omega decoupling factor for 4 different sites as a way of quantifying the contributions of radiation and stomatal conductance over the resulting water and carbon cycles. This gives us an indication of how the plant canopy is interacting with, and influencing the local microclimate. Ultimately, this should give us an indication of the ability of perennial crops to aid in the climate mitigation process. We hypothesized that the perennial site chosen would have omega values more similar to the omega values of a natural grassland rather than an annual crop site. Using AmeriFlux towers to determine the canopy values needed to calculate the omega decoupling factor, we focused on the Kernza perennial crops being grown at the Land Institute in Salina, Kansas (KLS), in comparison to a natural grassland in Manhattan, Kansas (KON), a typical land cover model in Lawrence, Kansas (KFS), and an annual crop site in Lamont, Oklahoma (ARM). These results will allow us to move forward in the investigation of perennial crops as a sustainable food source.

Coordinated Airborne Studies in the Tropics (CAST) Field Campaign Report

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

Vaughan, Geraint

The last field campaign held at the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility site on Manus Island, Papua New Guinea (PNG), was conducted in February 2014 as part of the Co-ordinated Airborne Studies in the Tropics (CAST) campaign. This campaign was a collaboration between the National Aeronautics and Space Administration (NASA), National Center for Atmospheric Research (NCAR), and the United Kingdom’s (UK) Natural Environment Research Council (NERC) to study the composition of the Tropical Tropopause Layer (TTL) and the impact of deep convection on this composition. There are three main areas of interest: i)more » transport of trace gases in the tropical atmosphere (especially short-lived halogenated compounds that can be lifted rapidly into the TTL, where they augment the stratospheric loading of these species); ii) formation of cirrus and its impact on the TTL; and iii) the upper-atmosphere water vapor budget. Overall, the aim was to improve understanding of the dynamical, radiative, and chemical role of the TTL. The Manus operation was a joint experiment between the Universities of Manchester and Cambridge and the UK National Centre for Atmospheric Science (NCAS). It consisted of two elements: an ozonesonde campaign to measure ozone vertical profiles through the TTL, and ground-based monitoring of ozone, halogenated hydrocarbons, and greenhouse gases to determine the composition of lower-boundary-layer air in the Warm Pool region. Thanks to the support from the ARM Climate Research Facility and the exemplary collaboration of ARM staff in the region, the campaign was very successful.« less

Model of outgrowths in the spiral galaxies NGC 4921 and NGC 7049 and the origin of spiral arms

NASA Astrophysics Data System (ADS)

Carlqvist, Per

2013-02-01

NGC 4921 and 7049 are two spiral galaxies presenting narrow, distinct dust features. A detailed study of the morphology of those features has been carried out using Hubble Space Telescope archival images. NGC 4921 shows a few but well-defined dust arms midway to its centre while NGC 7049 displays many more dusty features, mainly collected within a ring-shaped formation. Numerous dark and filamentary structures, called outgrowths, are found to protrude from the dusty arms in both galaxies. The outgrowths point both outwards and inwards in the galaxies. Mostly they are found to be V-shaped or Y-shaped with the branches connected to dark arm filaments. Often the stem of the Y appears to consist of intertwined filaments. Remarkably, the outgrowths show considerable similarities to elephant trunks in H ii regions. A model of the outgrowths, based on magnetized filaments, is proposed. The model provides explanations of both the shapes and orientations of the outgrowths. Most important, it can also give an account for their intertwined structures. It is found that the longest outgrowths are confusingly similar to dusty spiral arms. This suggests that some of the outgrowths can develop into such arms. The time-scale of the development is estimated to be on the order of the rotation period of the arms or shorter. Similar processes may also take place in other spiral galaxies. If so, the model of the outgrowths can offer a new approach to the old winding problem of spiral arms.

Human-arm-and-hand-dynamic model with variability analyses for a stylus-based haptic interface.

PubMed

Fu, Michael J; Cavuşoğlu, M Cenk

2012-12-01

Haptic interface research benefits from accurate human arm models for control and system design. The literature contains many human arm dynamic models but lacks detailed variability analyses. Without accurate measurements, variability is modeled in a very conservative manner, leading to less than optimal controller and system designs. This paper not only presents models for human arm dynamics but also develops inter- and intrasubject variability models for a stylus-based haptic device. Data from 15 human subjects (nine male, six female, ages 20-32) were collected using a Phantom Premium 1.5a haptic device for system identification. In this paper, grip-force-dependent models were identified for 1-3-N grip forces in the three spatial axes. Also, variability due to human subjects and grip-force variation were modeled as both structured and unstructured uncertainties. For both forms of variability, the maximum variation, 95 %, and 67 % confidence interval limits were examined. All models were in the frequency domain with force as input and position as output. The identified models enable precise controllers targeted to a subset of possible human operator dynamics.

An MR-compatible gyroscope-based arm movement tracking system.

PubMed

Shirinbayan, S Iman; Rieger, Jochem W

2017-03-15

Functional magnetic resonance imaging is well suited to link neural population activation with movement parameters of complex natural arm movements. However, currently existing MR-compatible arm tracking devices are not constructed to measure arm joint movement parameters of unrestricted movements. Therefore, to date most research focuses on simple arm movements or includes very little knowledge about the actual movement kinematics. We developed a low cost gyroscope-based arm movement tracking system (GAMTS) that features MR-compatibility. The system consists of dual-axis analogue gyroscopes that measure rotations of upper and lower arm joints. After MR artifact reduction, the rotation angles of the individual arm joints are calculated and used to animate a realistic arm model that is implemented in the OpenSim platform. The OpenSim platform can then provide the kinematics of any point on the arm model. In order to demonstrate the capabilities of the system, we first assessed the quality of reconstructed wrist movements in a low-noise environment where typical MR-related problems are absent and finally, we validated the reconstruction in the MR environment. The system provides the kinematics of the whole arm when natural unrestricted arm movements are performed inside the MR-scanner. The GAMTS is reliably capable of reconstructing the kinematics of trajectories and the reconstruction error is small in comparison with the movement induced variation of speed, displacement, and rotation. Moreover, the system can be used to probe brain areas for their correlation with movement kinematics. Copyright © 2017 Elsevier B.V. All rights reserved.

Accuracy Analysis and Validation of the Mars Science Laboratory (MSL) Robotic Arm

NASA Technical Reports Server (NTRS)

Collins, Curtis L.; Robinson, Matthew L.

2013-01-01

The Mars Science Laboratory (MSL) Curiosity Rover is currently exploring the surface of Mars with a suite of tools and instruments mounted to the end of a five degree-of-freedom robotic arm. To verify and meet a set of end-to-end system level accuracy requirements, a detailed positioning uncertainty model of the arm was developed and exercised over the arm operational workspace. Error sources at each link in the arm kinematic chain were estimated and their effects propagated to the tool frames.A rigorous test and measurement program was developed and implemented to collect data to characterize and calibrate the kinematic and stiffness parameters of the arm. Numerous absolute and relative accuracy and repeatability requirements were validated with a combination of analysis and test data extrapolated to the Mars gravity and thermal environment. Initial results of arm accuracy and repeatability on Mars demonstrate the effectiveness of the modeling and test program as the rover continues to explore the foothills of Mount Sharp.

Rasch measurement: the Arm Activity measure (ArmA) passive function sub-scale.

PubMed

Ashford, Stephen; Siegert, Richard J; Alexandrescu, Roxana

2016-01-01

To evaluate the conformity of the Arm Activity measure (ArmA) passive function sub-scale to the Rasch model. A consecutive cohort of patients (n = 92) undergoing rehabilitation, including upper limb rehabilitation and spasticity management, at two specialist rehabilitation units were included. Rasch analysis was used to examine scaling and conformity to the model. Responses were analysed using Rasch unidimensional measurement models (RUMM 2030). The following aspects were considered: overall model and individual item fit statistics and fit residuals, internal reliability, item response threshold ordering, item bias, local dependency and unidimensionality. ArmA contains both active and passive function sub-scales, but in this analysis only the passive function sub-scale was considered. Four of the seven items in the ArmA passive function sub-scale initially had disordered thresholds. These items were rescored to four response options, which resulted in ordered thresholds for all items. Once the items with disordered thresholds had been rescored, item bias was not identified for age, global disability level or diagnosis, but with a small difference in difficulty between males and females for one item of the scale. Local dependency was not observed and the unidimensionality of the sub-scale was supported and good fit to the Rasch model was identified. The person separation index (PSI) was 0.95 indicating that the scale is able to reliably differentiate at least two groups of patients. The ArmA passive function sub-scale was shown in this evaluation to conform to the Rasch model once disordered thresholds had been addressed. Using the logit scores produced by the Rasch model it was possible to convert this back to the original scale range. Implications for Rehabilitation The ArmA passive function sub-scale was shown, in this evaluation, to conform to the Rasch model once disordered thresholds had been addressed and therefore to be a clinically applicable and potentially useful hierarchical measure. Using Rasch logit scores it has be possible to convert back to the original ordinal scale range and provide an indication of real change to enable evaluation of clinical outcome of importance to patients and clinicians.

Effect of torso flexion on the lumbar torso extensor muscle sagittal plane moment arms.

PubMed

Jorgensen, Michael J; Marras, William S; Gupta, Purnendu; Waters, Thomas R

2003-01-01

Accurate anatomical inputs for biomechanical models are necessary for valid estimates of internal loading. The magnitude of the moment arm of the lumbar erector muscle group is known to vary as a function of such variables as gender. Anatomical evidence indicates that the moment arms decrease during torso flexion. However, moment arm estimates in biomechanical models that account for individual variability have been derived from imaging studies from supine postures. Quantify the sagittal plane moment arms of the lumbar erector muscle group as a function of torso flexion, and identify individual characteristics that are associated with the magnitude of the moment arms as a function of torso flexion. Utilization of a 0.3 Tesla Open magnetic resonance image (MRI) to image and quantify the moment arm of the right erector muscle group as a function of gender and torso flexion. Axial MRI images through and parallel to each of the lumbar intervertebral discs at four torso flexion angles were obtained from 12 male and 12 female subjects in a lateral recumbent posture. Multivariate analysis of variance was used to investigate the differences in the moment arms at different torso flexion angles, whereas hierarchical linear regression was used to investigate associations with individual anthropometric characteristics and spinal posture. The largest decrease in the lumbar erector muscle group moment arm from neutral to 45-degree flexion occurred at the L5-S1 level (9.7% and 8.9% for men and women, respectively). Measures of spinal curvature (L1-S1 lordosis), body mass and trunk characteristics (depth or circumference) were associated with the varying moment arm at most lumbar levels. The sagittal plane moment arms of the lumbar erector muscle mass decrease as the torso flexes forward. The change in moment arms as a function of torso flexion may have an impact on prediction of spinal loading in biomechanical models.

Biogenic Aerosols – Effects on Climate and Clouds. Cloud Optical Depth (COD) Sensor Three-Waveband Spectrally-Agile Technique (TWST) Field Campaign Report

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

Niple, E. R.; Scott, H. E.

2016-04-01

This report describes the data collected by the Three-Waveband Spectrally-agile Technique (TWST) sensor deployed at Hyytiälä, Finland from 16 July to 31 August 2014 as a guest on the Biogenic Aerosols Effects on Climate and Clouds (BAECC) campaign. These data are currently available from the Atmospheric Radiation Measurement (ARM) Data Archive website and consists of Cloud Optical Depth (COD) measurements for the clouds directly overhead approximately every second (with some dropouts described below) during the daylight periods. A good range of cloud conditions were observed from clear sky to heavy rainfall.

Structural Studies of Three-Arm Star Block Copolymers Exposed to Extreme Stretch Suggests a Persistent Polymer Tube

NASA Astrophysics Data System (ADS)

Mortensen, Kell; Borger, Anine L.; Kirkensgaard, Jacob J. K.; Garvey, Christopher J.; Almdal, Kristoffer; Dorokhin, Andriy; Huang, Qian; Hassager, Ole

2018-05-01

We present structural small-angle neutron scattering studies of a three-armed polystyrene star polymer with short deuterated segments at the end of each arm. We show that the form factor of the three-armed star molecules in the relaxed state agrees with that of the random phase approximation of Gaussian chains. Upon exposure to large extensional flow conditions, the star polymers change conformation resulting in a highly stretched structure that mimics a fully extended three-armed tube model. All three arms are parallel to the flow, one arm being either in positive or negative stretching direction, while the two other arms are oriented parallel, right next to each other in the direction opposite to the first arm.

Mathematical Model of Armed Helicopter vs Tank Duel

DTIC Science & Technology

The purpose of this thesis is to mathematically model a duel between the armed helicopter and the tank. In addition to providing a parametric...analysis of B. O. Koopman’s classical Detection-Destruction Duel , two additional models were constructed and analyzed. All three models stem from stochastic

Parameterizing atmosphere-land surface exchange for climate models with satellite data: A case study for the Southern Great Plains CART site

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

Gao, W.

High-resolution satellite data provide detailed, quantitative descriptions of land surface characteristics over large areas so that objective scale linkage becomes feasible. With the aid of satellite data, Sellers et al. and Wood and Lakshmi examined the linearity of processes scaled up from 30 m to 15 km. If the phenomenon is scale invariant, then the aggregated value of a function or flux is equivalent to the function computed from aggregated values of controlling variables. The linear relation may be realistic for limited land areas having no large surface contrasts to cause significant horizontal exchange. However, for areas with sharp surfacemore » contrasts, horizontal exchange and different dynamics in the atmospheric boundary may induce nonlinear interactions, such as at interfaces of land-water, forest-farm land, and irrigated crops-desert steppe. The linear approach, however, represents the simplest scenario, and is useful for developing an effective scheme for incorporating subgrid land surface processes into large-scale models. Our studies focus on coupling satellite data and ground measurements with a satellite-data-driven land surface model to parameterize surface fluxes for large-scale climate models. In this case study, we used surface spectral reflectance data from satellite remote sensing to characterize spatial and temporal changes in vegetation and associated surface parameters in an area of about 350 {times} 400 km covering the southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site of the US Department of Energy`s Atmospheric Radiation Measurement (ARM) Program.« less

Mechanisms affecting the transition from shallow to deep convection over land: Inferences from observations collected at the ARM Southern Great Plains site

NASA Astrophysics Data System (ADS)

Zhang, Y.; Klein, S. A.

2009-12-01

11 years of summertime observations at the Atmospheric Radiation Measurement (ARM) Climate Research Facility Southern Great Plains (SGP) site are used to investigate mechanisms controlling the transition from shallow to deep convection over land. A more humid environment above the boundary layer favors the occurrence of late-afternoon heavy precipitation events. The higher moisture content is brought by wind from south. Greater boundary layer inhomogeneity in moist static energy (MSE) is correlated to larger rain rates at the initial stage of precipitation. MSE inhomogeneity is attributed to both moisture and temperature fields, and is correlated with westerly winds. In an examination of afternoon rain statistics, higher relative humidity above the boundary layer is correlated to an earlier onset and longer duration of precipitation, while greater boundary layer inhomogeneity and atmospheric instability are positively correlated to the total rain amount and the maximum rain rate. On balance, these observations favor theories for the transition that involve a moist free troposphere and boundary layer heterogeneity in preference to those that involve convective available potential energy or convective inhibition. Thus the evidence presented here supports the current emphasis in the modeling community on the entraining nature of convection and the role of boundary layer cold pools in triggering new convection.

Marine ARM GPCI Investigation of Clouds Psychrometer Field Campaign Report

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

Reynolds, R Michael; Lewis, Ernie

2016-09-01

One of the most critical measurements in the suite of meteorological measurements used for the calculation of evaporation and latent heat flux is the relative humidity (RH). In order to achieve an overall net flux uncertainty < 10 W/m 2 (Bradley and Fairall, 2006), the RH must be accurate to < 2 %RH. Anyone experienced in shipboard meteorological measurements will recognize that this is a tough specification. During the U.S. Department of Energy (DOE) Marine Atmospheric Radiation Measurement (ARM) Climate Research Facility Global Energy and Water Experiment (GEWEX) Cloud System Study (GCSS) Pacific Cross-Section Intercomparison (GPCI) Investigation of Clouds (MAGIC)more » experiment, the meteorological package used three different RH sensors. We found approximately 3-4 % differences between units. To arbitrate the differences and to track calibration drift over the months of exposure, we used a precision psychrometer. The Assmann Psychrometer, Model 430101 is a classic, mercury-in-glass instrument that gives a precise measure of the wet and dry bulb temperatures from which atmospheric humidity and RH are computed. On a regular basis, typically after each balloon launch, a technician took the psychrometer to an exposed location on the bridge roof. That was just below the instruments on the mast and high enough into the mixed layer that the difference is negligible.« less

An observational and modeling study of the regional impacts of climate variability

NASA Astrophysics Data System (ADS)

Horton, Radley M.

Climate variability has large impacts on humans and their agricultural systems. Farmers are at the center of this agricultural network, but it is often agricultural planners---regional planners, extension agents, commodity groups and cooperatives---that translate climate information for users. Global climate models (GCMs) are a leading tool for understanding and predicting climate and climate change. Armed with climate projections and forecasts, agricultural planners adapt their decision-making to optimize outcomes. This thesis explores what GCMs can, and cannot, tell us about climate variability and change at regional scales. The question is important, since high-quality regional climate projections could assist farmers and regional planners in key management decisions, contributing to better agricultural outcomes. To answer these questions, climate variability and its regional impacts are explored in observations and models for the current and future climate. The goals are to identify impacts of observed variability, assess model simulation of variability, and explore how climate variability and its impacts may change under enhanced greenhouse warming. Chapter One explores how well Goddard Institute for Space Studies (GISS) atmospheric models, forced by historical sea surface temperatures (SST), simulate climatology and large-scale features during the exceptionally strong 1997--1999 El Nino Southern Oscillation (ENSO) cycle. Reasonable performance in this 'proof of concept' test is considered a minimum requirement for further study of variability in models. All model versions produce appropriate local changes with ENSO, indicating that with correct ocean temperatures these versions are capable of simulating the large-scale effects of ENSO around the globe. A high vertical resolution model (VHR) provides the best simulation. Evidence is also presented that SST anomalies outside the tropical Pacific may play a key role in generating remote teleconnections even during El Nino events. Based on the results from Chapter One, the analysis is expanded in several ways in Chapter Two. To gain a more complete and statistically meaningful understanding of ENSO, a 25 year time period is used instead of a single event. To gain a fuller understanding of climate variability, additional patterns are analyzed. Finally analysis is conducted at the regional scales that are of interest to farmers and agricultural planners. Key findings are that GISS ModelE can reproduce: (1) the spatial pattern associated with two additional related modes, the Arctic Oscillation (AO) and the North Atlantic Oscillation (NAO); (2) rainfall patterns in Indonesia; and (3) dynamical features such as sea level pressure (SLP) gradients and wind in the study regions. When run in coupled mode, the same model reproduces similar modes spatially but with reduced variance and weak teleconnections. Since Chapter Two identified Western Indonesia as the region where GCMs hold the most promise for agricultural applications, in Chapter Three a finer spatial and temporal scale analysis of ENSO's effects is presented. Agricultural decision-making is also linked to ENSO's climate effects. Early rainy season precipitation and circulation, and same-season planting and harvesting dates, are shown to be sensitive to ENSO. The locus of ENSO convergence and rainfall anomalies is shown to be near the axis of rainy season establishment, defined as the 6--8 mm/day isohyet, an approximate threshold for irrigated rice cultivation. As the axis tracks south and east between October and January, so do ENSO anomalies. Circulation anomalies associated with ENSO are shown to be similar to those associated with rainfall anomalies, suggesting that long lead-time ENSO forecasts may allow more adaptation than 'wait and see' methods, with little loss of forecast skill. Additional findings include: (1) rice and corn yields are lower (higher) during dry (wet) trimesters and El Nino (La Nina) years; and (2) a statistically significant negative relationship exists between malaria cases and ENSO. The final chapter adds climate change to the climate variability story. Under high CO2, the model able to capture ENSO dynamics---an atmospheric model coupled to the Cane-Zebiak ocean model ('C4' here)---generates more El Nino-like mean conditions in the tropical Pacific. These changes produce a 4x larger increase in maximum precipitation with warming in C4 than an atmospheric model with a slab ocean (Q4), dramatically enhancing the Pacific Hadley and Walker circulations, and through positive feedbacks, increasing the global temperature. Near Nordeste warming alone (Q4) produces added rainfall, which in C4 is partially cancelled out by El Nino-like changes in the Walker Cell. Both Q4 and C4 produce small changes in Indonesia, although C4 generates large circulation and precipitation anomalies over the Western Indian Ocean. C4 changes in the midlatitudes produce a very strong Pacific North American pattern (PNA) response that dominates a small positive AO change associated with Q4. These PNA changes produce increased rainfall over the Southeastern United States (SEUS) in C4. AO and NAO-like variability are also found to increase with enhanced CO2. This thesis highlights how climate variability influences regional climate variability, with an emphasis on four regions: Nordeste, Brazil, Western Indonesia, the Southeastern United States (SEUS), and the Mediterranean. It links El Nino-driven delay in the onset of rainy season drivers in Western Indonesia to decision-making about when to plant the year's largest crop. In a coupled configuration, the GISS GCM produces strong El Nino-like changes with global warming. This result suggests that the impacts---climatological and agricultural---of climate change may ultimately exceed the impacts of current variability. Somewhat paradoxically, these results indicate that one of the central manifestations of climate change is likely to be changes in patterns of climate variability and their regional impacts.

Feedback control of vibrations in a moving flexible robot arm with rotary and prismatic joints

NASA Technical Reports Server (NTRS)

Wang, P. K. C.; Wei, Jin-Duo

1987-01-01

A robot with a long extendible flexible arm which can also undergo both vertical translation and rotary motion is considered. First, A distributed-parameter model for the robot arm dynamics is developed. It is found that the extending motion could enhance the arm vibrations. Then, a Galerkin-type approximation based on an appropriate time-dependent basis for the solution space is used to obtain an approximate finite-dimensional model for simulation studies. A feedback control for damping the motion-induced vibrations is derived by considering the time rate-of-change of the total vibrational energy of the flexible arm. The authors conclude with some simulation results for a special case with the proposed control law.

Overview of the 2010 Carbonaceous Aerosols and Radiative Effects Study (CARES)

NASA Astrophysics Data System (ADS)

Zaveri, R. A.; Shaw, W. J.; Cziczo, D. J.; Schmid, B.; Ferrare, R. A.; Alexander, M. L.; Alexandrov, M.; Alvarez, R. J.; Arnott, W. P.; Atkinson, D. B.; Baidar, S.; Banta, R. M.; Barnard, J. C.; Beranek, J.; Berg, L. K.; Brechtel, F.; Brewer, W. A.; Cahill, J. F.; Cairns, B.; Cappa, C. D.; Chand, D.; China, S.; Comstock, J. M.; Dubey, M. K.; Easter, R. C.; Erickson, M. H.; Fast, J. D.; Floerchinger, C.; Flowers, B. A.; Fortner, E.; Gaffney, J. S.; Gilles, M. K.; Gorkowski, K.; Gustafson, W. I.; Gyawali, M.; Hair, J.; Hardesty, R. M.; Harworth, J. W.; Herndon, S.; Hiranuma, N.; Hostetler, C.; Hubbe, J. M.; Jayne, J. T.; Jeong, H.; Jobson, B. T.; Kassianov, E. I.; Kleinman, L. I.; Kluzek, C.; Knighton, B.; Kolesar, K. R.; Kuang, C.; Kubátová, A.; Langford, A. O.; Laskin, A.; Laulainen, N.; Marchbanks, R. D.; Mazzoleni, C.; Mei, F.; Moffet, R. C.; Nelson, D.; Obland, M. D.; Oetjen, H.; Onasch, T. B.; Ortega, I.; Ottaviani, M.; Pekour, M.; Prather, K. A.; Radney, J. G.; Rogers, R. R.; Sandberg, S. P.; Sedlacek, A.; Senff, C. J.; Senum, G.; Setyan, A.; Shilling, J. E.; Shrivastava, M.; Song, C.; Springston, S. R.; Subramanian, R.; Suski, K.; Tomlinson, J.; Volkamer, R.; Wallace, H. W.; Wang, J.; Weickmann, A. M.; Worsnop, D. R.; Yu, X.-Y.; Zelenyuk, A.; Zhang, Q.

2012-08-01

Substantial uncertainties still exist in the scientific understanding of the possible interactions between urban and natural (biogenic) emissions in the production and transformation of atmospheric aerosol and the resulting impact on climate change. The US Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) program's Carbonaceous Aerosol and Radiative Effects Study (CARES) carried out in June 2010 in Central Valley, California, was a comprehensive effort designed to improve this understanding. The primary objective of the field study was to investigate the evolution of secondary organic and black carbon aerosols and their climate-related properties in the Sacramento urban plume as it was routinely transported into the forested Sierra Nevada foothills area. Urban aerosols and trace gases experienced significant physical and chemical transformations as they mixed with the reactive biogenic hydrocarbons emitted from the forest. Two heavily-instrumented ground sites - one within the Sacramento urban area and another about 40 km to the northeast in the foothills area - were set up to characterize the evolution of meteorological variables, trace gases, aerosol precursors, aerosol size, composition, and climate-related properties in freshly polluted and "aged" urban air. On selected days, the DOE G-1 aircraft was deployed to make similar measurements upwind and across the evolving Sacramento plume in the morning and again in the afternoon. The NASA B-200 aircraft, carrying remote sensing instruments, was also deployed to characterize the vertical and horizontal distribution of aerosols and aerosol optical properties within and around the plume. This overview provides: (a) the scientific background and motivation for the study, (b) the operational and logistical information pertinent to the execution of the study, (c) an overview of key observations and initial findings from the aircraft and ground-based sampling platforms, and (d) a roadmap of planned data analyses and focused modeling efforts that will facilitate the integration of new knowledge into improved representations of key aerosol processes and properties in climate models.

Overview of the 2010 Carbonaceous Aerosols and Radiative Effects Study (CARES)

NASA Astrophysics Data System (ADS)

Zaveri, R. A.; Shaw, W. J.; Cziczo, D. J.; Schmid, B.; Alexander, M. L.; Alexandrov, M.; Alvarez, R. J.; Arnott, W. P.; Atkinson, D. B.; Baidar, S.; Banta, R. M.; Barnard, J. C.; Beranek, J.; Berg, L. K.; Brechtel, F.; Brewer, W. A.; Cahill, J. F.; Cairns, B.; Cappa, C. D.; Chand, D.; China, S.; Comstock, J. M.; Dubey, M. K.; Easter, R. C.; Fast, J. D.; Floerchinger, C.; Flowers, B. A.; Fortner, E.; Gaffney, J. S.; Gilles, M. K.; Gorkowski, K.; Gustafson, W. I.; Gyawali, M.; Hair, J.; Hardesty, R. M.; Harworth, J. W.; Herndon, S.; Hiranuma, N.; Hostetler, C.; Hubbe, J. M.; Jayne, J. T.; Jeong, H.; Jobson, B. T.; Kleinman, L. I.; Kluzek, C.; Knighton, B.; Kolesar, K. R.; Kuang, C.; Langford, A. O.; Laskin, A.; Marchbanks, R. D.; Mazzoleni, C.; Mei, F.; Moffet, R. C.; Nelson, D.; Obland, M. D.; Oetjen, H.; Onasch, T. B.; Ortega, I.; Ottaviani, M.; Pekour, M.; Prather, K. A.; Radney, J. G.; Rogers, R. R.; Sandberg, S. P.; Sedlacek, A.; Senff, C. J.; Senum, G.; Setyan, A.; Shilling, J. E.; Shrivastava, M.; Song, C.; Springston, S. R.; Subramanian, R.; Tomlinson, J.; Volkamer, R.; Wallace, H. W.; Wang, J.; Weickmann, A. M.; Yu, X.-Y.; Zelenyuk, A.; Zhang, Q.

2012-01-01

Substantial uncertainties still exist in the scientific understanding of the possible interactions between urban and natural (biogenic) emissions in the production and transformation of atmospheric aerosol and the resulting impact on climate change. The US Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) program's Carbonaceous Aerosol and Radiative Effects Study (CARES) carried out in June 2010 in Central Valley, California, was a comprehensive effort designed to improve this understanding. The primary objective of the field study was to investigate the evolution of secondary organic and black carbon aerosols and their climate-related properties in the Sacramento urban plume as it was routinely transported into the forested Sierra Nevada foothills area. Urban aerosols and trace gases experienced significant physical and chemical transformations as they mixed with the reactive biogenic hydrocarbons emitted from the forest. Two heavily-instrumented ground sites - one within the Sacramento urban area and another about 40 km to the northeast in the foothills area - were set up to characterize the evolution of meteorological variables, trace gases, aerosol precursors, aerosol size, composition, and climate-related properties in freshly polluted and "aged" urban air. On selected days, the DOE G-1 aircraft was deployed to make similar measurements upwind and across the evolving Sacramento plume in the morning and again in the afternoon. The NASA B-200 aircraft, carrying remote sensing instruments, was also deployed to characterize the vertical and horizontal distribution of aerosols and aerosol optical properties within and around the plume. This overview provides: (a) the scientific background and motivation for the study, (b) the operational and logistical information pertinent to the execution of the study, (c) an overview of key observations and initial results from the aircraft and ground-based sampling platforms, and (d) a roadmap of planned data analyses and focused modeling efforts that will facilitate the integration of new knowledge into improved representations of key aerosol processes in climate models.

An improved biomechanical model for simulating the strain of the hand-arm system under vibration stress.

PubMed

Fritz, M

1991-01-01

In order to define relationships between the vibration stress and the strain of the human hand-arm system a biomechanical model was developed. The four masses of the model representing the hand, the forearm and the upper arm were connected by dampers and springs in two perpendicular directions. Simulating muscle activity, damped torsion springs were included additionally. The motions of the model were described by a differential matrix equation which was solved by using a 'transfer matrix routine' as well as by numerical integration. Thus, functions with harmonic or transient time courses could be selected as an excitation. The simulated vibrations were compared with those of other hand-arm models. The forces and torques transmitted between the masses, and the energy dissipated by the dampers were computed for several combinations of exciter frequencies and accelerations. The dependence of torques upon excitation agreed fairly well with the behaviour of the arm muscles under vibration as described by various investigators. At frequencies above 100 Hz the energy was dissipated mainly by the dampers between the masses near to the exciter. Transferring this result to the hand-arm system it shows that at high frequencies energy is dissipated by the hand and its palmar tissues and this might be one cause for the incidence of vibration-induced white finger disease.

PEO Integration Acronym Book

DTIC Science & Technology

2011-02-01

Command CASE Computer Aided Software Engineering CASEVAC Casualty Evacuation CASTFOREM Combined Arms And Support Task Force Evaluation Model CAT Center For...Advanced Technologies CAT Civil Affairs Team CAT Combined Arms Training CAT Crew Integration CAT Crisis Action Team CATIA Computer-Aided Three...Dimensional Interactive Application CATOX Catalytic Oxidation CATS Combined Arms Training Strategy CATT Combined Arms Tactical Trainer CATT Computer

Towards a real-time interface between a biomimetic model of sensorimotor cortex and a robotic arm

PubMed Central

Dura-Bernal, Salvador; Chadderdon, George L; Neymotin, Samuel A; Francis, Joseph T; Lytton, William W

2015-01-01

Brain-machine interfaces can greatly improve the performance of prosthetics. Utilizing biomimetic neuronal modeling in brain machine interfaces (BMI) offers the possibility of providing naturalistic motor-control algorithms for control of a robotic limb. This will allow finer control of a robot, while also giving us new tools to better understand the brain’s use of electrical signals. However, the biomimetic approach presents challenges in integrating technologies across multiple hardware and software platforms, so that the different components can communicate in real-time. We present the first steps in an ongoing effort to integrate a biomimetic spiking neuronal model of motor learning with a robotic arm. The biomimetic model (BMM) was used to drive a simple kinematic two-joint virtual arm in a motor task requiring trial-and-error convergence on a single target. We utilized the output of this model in real time to drive mirroring motion of a Barrett Technology WAM robotic arm through a user datagram protocol (UDP) interface. The robotic arm sent back information on its joint positions, which was then used by a visualization tool on the remote computer to display a realistic 3D virtual model of the moving robotic arm in real time. This work paves the way towards a full closed-loop biomimetic brain-effector system that can be incorporated in a neural decoder for prosthetic control, to be used as a platform for developing biomimetic learning algorithms for controlling real-time devices. PMID:26709323

United States news media and climate change in the era of US President Trump.

PubMed

Park, David J

2018-03-01

The Donald J Trump administration's strategy to disengage and downplay the Paris Climate Agreement will likely result in a slight decrease in the already low levels of US news media global warming coverage. This is because significant limitations with the news media's ability to adequately cover climate change predated the administration. First, studies indicate that advertising interests and editors have always challenged journalists' abilities to adequately report on climate change issues. Instead of climate change stories, editors often prefer more sensational topics that garner higher ratings and approval with advertisers. Second, the journalistic norm of balance and the role of sourcing give climate skeptics exceptional media exposure, which creates a "false balance" or equivalency between skeptics and scientists. Third, the massive power and influence of the fossil fuel industry's public relations arm has also had a tremendous impact on public (mis)understanding of climate change. Fourth, a trend toward declining climate change coverage and "climate silence" in US media is developing. Media corporations have substantially eliminated the number of environmental journalists that cover climate change. The overall effect of these limitations distorts public understanding of climate change and delays potential government action. Moving away from a predominantly commercial media system to one with a substantial noncommercial component can improve US journalism, whereas using advertising to increase rates for environmentally unsound products and services may also help mitigate global warming. Integr Environ Assess Manag 2018;14:202-204. © 2018 SETAC. © 2018 SETAC.

Spiral-arm instability: giant clump formation via fragmentation of a galactic spiral arm

NASA Astrophysics Data System (ADS)

Inoue, Shigeki; Yoshida, Naoki

2018-03-01

Fragmentation of a spiral arm is thought to drive the formation of giant clumps in galaxies. Using linear perturbation analysis for self-gravitating spiral arms, we derive an instability parameter and define the conditions for clump formation. We extend our analysis to multicomponent systems that consist of gas and stars in an external potential. We then perform numerical simulations of isolated disc galaxies with isothermal gas, and compare the results with the prediction of our analytic model. Our model describes accurately the evolution of the spiral arms in our simulations, even when spiral arms dynamically interact with one another. We show that most of the giant clumps formed in the simulated disc galaxies satisfy the instability condition. The clump masses predicted by our model are in agreement with the simulation results, but the growth time-scale of unstable perturbations is overestimated by a factor of a few. We also apply our instability analysis to derive scaling relations of clump properties. The expected scaling relation between the clump size, velocity dispersion, and circular velocity is slightly different from that given by the Toomre instability analyses, but neither is inconsistent with currently available observations. We argue that the spiral-arm instability is a viable formation mechanism of giant clumps in gas-rich disc galaxies.

GoAmazon 2014/15. SRI-PTR-ToFMS Field Campaign Report

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

Guenther, A.

Our science team, including Dr. Alex Guenther (previously at Pacific Northwest National Laboratory (PNNL) and now at the University of California, Irvine) Dr. Saewung Kim and Dr. Roger Seco, and Dr. Jim Smith (previously at NCAR and now at UC Irvine), deployed a selected reagent ion – proton transfer reaction – time-of-flight mass spectrometer (SRI-PTR-TOFMS) to the T3 site during the GoAmazon study. One of the major uncertainties in climate model simulations is the effects of aerosols on radiative forcing, and a better understanding of the factors controlling aerosol distributions and life cycle is urgently needed. Aerosols contribute directly tomore » the Earth’s radiation balance by scattering or absorbing light as a function of their physical properties and indirectly through particle-cloud interactions that lead to cloud formation and the modification of cloud properties. On a global scale, the dominant source of organic aerosol is biogenic volatile organic compounds (BVOC) emitted from terrestrial ecosystems. These organic aerosols are a major part of the total mass of all airborne particles and are currently not sufficiently represented in climate models. To incorporate quantitatively the effects of BVOCs and their oxidation products on biogenic organic aerosol (BOA) requires parameterization of their production in terrestrial ecosystems and their atmospheric transformations. This project was designed to reduce the gaps in our understanding of how these processes control BVOCs and BOAs, and their impact on climate. This was accomplished by wet and dry season measurements at the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility T3 site along with a comprehensive suite of complementary measurements. The specific goals were to 1) measure and mechanistically understand the factors affecting aerosol distributions over a tropical rain forest, especially the effects of anthropogenic pollution as a perturbation to the natural state, and 2) develop and implement an upscaling analysis from this new data set and knowledge of aerosol distributions to prognosticate possible climatic impacts of present-day urban pollution and possibly greater pollution in the future.« less

The influence of Cloud Longwave Scattering together with a state-of-the-art Ice Longwave Optical Parameterization in Climate Model Simulations

NASA Astrophysics Data System (ADS)

Chen, Y. H.; Kuo, C. P.; Huang, X.; Yang, P.

2017-12-01

Clouds play an important role in the Earth's radiation budget, and thus realistic and comprehensive treatments of cloud optical properties and cloud-sky radiative transfer are crucial for simulating weather and climate. However, most GCMs neglect LW scattering effects by clouds and tend to use inconsistent cloud SW and LW optical parameterizations. Recently, co-authors of this study have developed a new LW optical properties parameterization for ice clouds, which is based on ice cloud particle statistics from MODIS measurements and state-of-the-art scattering calculation. A two-stream multiple-scattering scheme has also been implemented into the RRTMG_LW, a widely used longwave radiation scheme by climate modeling centers. This study is to integrate both the new LW cloud-radiation scheme for ice clouds and the modified RRTMG_LW with scattering capability into the NCAR CESM to improve the cloud longwave radiation treatment. A number of single column model (SCM) simulations using the observation from the ARM SGP site on July 18 to August 4 in 1995 are carried out to assess the impact of new LW optical properties of clouds and scattering-enabled radiation scheme on simulated radiation budget and cloud radiative effect (CRE). The SCM simulation allows interaction between cloud and radiation schemes with other parameterizations, but the large-scale forcing is prescribed or nudged. Comparing to the results from the SCM of the standard CESM, the new ice cloud optical properties alone leads to an increase of LW CRE by 26.85 W m-2 in average, as well as an increase of the downward LW flux at surface by 6.48 W m-2. Enabling LW cloud scattering further increases the LW CRE by another 3.57 W m-2 and the downward LW flux at the surface by 0.2 W m-2. The change of LW CRE is mainly due to an increase of cloud top height, which enhances the LW CRE. A long-term simulation of CESM will be carried out to further understand the impact of such changes on simulated climates.

Reach Adaptation: What Determines Whether We Learn an Internal Model of the Tool or Adapt the Model of Our Arm?

PubMed Central

Kluzik, JoAnn; Diedrichsen, Jörn; Shadmehr, Reza; Bastian, Amy J.

2008-01-01

We make errors when learning to use a new tool. However, the cause of error may be ambiguous: is it because we misestimated properties of the tool or of our own arm? We considered a well-studied adaptation task in which people made goal-directed reaching movements while holding the handle of a robotic arm. The robot produced viscous forces that perturbed reach trajectories. As reaching improved with practice, did people recalibrate an internal model of their arm, or did they build an internal model of the novel tool (robot), or both? What factors influenced how the brain solved this credit assignment problem? To investigate these questions, we compared transfer of adaptation between three conditions: catch trials in which robot forces were turned off unannounced, robot-null trials in which subjects were told that forces were turned off, and free-space trials in which subjects still held the handle but watched as it was detached from the robot. Transfer to free space was 40% of that observed in unannounced catch trials. We next hypothesized that transfer to free space might increase if the training field changed gradually, rather than abruptly. Indeed, this method increased transfer to free space from 40 to 60%. Therefore although practice with a novel tool resulted in formation of an internal model of the tool, it also appeared to produce a transient change in the internal model of the subject's arm. Gradual changes in the tool's dynamics increased the extent to which the nervous system recalibrated the model of the subject's own arm. PMID:18596187

Extrinsic and intrinsic index finger muscle attachments in an OpenSim upper-extremity model.

PubMed

Lee, Jong Hwa; Asakawa, Deanna S; Dennerlein, Jack T; Jindrich, Devin L

2015-04-01

Musculoskeletal models allow estimation of muscle function during complex tasks. We used objective methods to determine possible attachment locations for index finger muscles in an OpenSim upper-extremity model. Data-driven optimization algorithms, Simulated Annealing and Hook-Jeeves, estimated tendon locations crossing the metacarpophalangeal (MCP), proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints by minimizing the difference between model-estimated and experimentally-measured moment arms. Sensitivity analysis revealed that multiple sets of muscle attachments with similar optimized moment arms are possible, requiring additional assumptions or data to select a single set of values. The most smooth muscle paths were assumed to be biologically reasonable. Estimated tendon attachments resulted in variance accounted for (VAF) between calculated moment arms and measured values of 78% for flex/extension and 81% for ab/adduction at the MCP joint. VAF averaged 67% at the PIP joint and 54% at the DIP joint. VAF values at PIP and DIP joints partially reflected the constant moment arms reported for muscles about these joints. However, all moment arm values found through optimization were non-linear and non-constant. Relationships between moment arms and joint angles were best described with quadratic equations for tendons at the PIP and DIP joints.

Learning and Control Model of the Arm for Loading

NASA Astrophysics Data System (ADS)

Kim, Kyoungsik; Kambara, Hiroyuki; Shin, Duk; Koike, Yasuharu

We propose a learning and control model of the arm for a loading task in which an object is loaded onto one hand with the other hand, in the sagittal plane. Postural control during object interactions provides important points to motor control theories in terms of how humans handle dynamics changes and use the information of prediction and sensory feedback. For the learning and control model, we coupled a feedback-error-learning scheme with an Actor-Critic method used as a feedback controller. To overcome sensory delays, a feedforward dynamics model (FDM) was used in the sensory feedback path. We tested the proposed model in simulation using a two-joint arm with six muscles, each with time delays in muscle force generation. By applying the proposed model to the loading task, we showed that motor commands started increasing, before an object was loaded on, to stabilize arm posture. We also found that the FDM contributes to the stabilization by predicting how the hand changes based on contexts of the object and efferent signals. For comparison with other computational models, we present the simulation results of a minimum-variance model.

Dynamics, thermodynamics, radiation, and cloudiness associated with cumulus-topped marine boundary layers

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

Ghate, Virendra P.; Miller, Mark

The overall goal of this project was to improve the understanding of marine boundary clouds by using data collected at the Atmospheric Radiation Measurement (ARM) sites, so that they can be better represented in global climate models (GCMs). Marine boundary clouds are observed regularly over the tropical and subtropical oceans. They are an important element of the Earth’s climate system because they have substantial impact on the radiation budget together with the boundary layer moisture, and energy transports. These clouds also have an impact on large-scale precipitation features like the Inter Tropical Convergence Zone (ITCZ). Because these clouds occur atmore » temporal and spatial scales much smaller than those relevant to GCMs, their effects and the associated processes need to be parameterized in GCM simulations aimed at predicting future climate and energy needs. Specifically, this project’s objectives were to (1) characterize the surface turbulent fluxes, boundary layer thermodynamics, radiation field, and cloudiness associated with cumulus-topped marine boundary layers; (2) explore the similarities and differences in cloudiness and boundary layer conditions observed in the tropical and trade-wind regions; and (3) understand similarities and differences by using a simple bulk boundary layer model. In addition to working toward achieving the project’s three objectives, we also worked on understanding the role played by different forcing mechanisms in maintaining turbulence within cloud-topped boundary layers We focused our research on stratocumulus clouds during the first phase of the project, and cumulus clouds during the rest of the project. Below is a brief description of manuscripts published in peer-reviewed journals that describe results from our analyses.« less

Biomass Burning Observation Project (BBOP) Final Campaign Report

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

Kleinman, LI; Sedlacek, A. J.

2016-01-01

The Biomass Burning Observation Project (BBOP) was conducted to obtain a better understanding of how aerosols generated from biomass fires affect the atmosphere and climate. It is estimated that 40% of carbonaceous aerosol produced originates from biomass burning—enough to affect regional and global climate. Several biomass-burning studies have focused on tropical climates; however, few campaigns have been conducted within the United States, where millions of acres are burned each year, trending to higher values and greater climate impacts because of droughts in the West. Using the Atmospheric Radiation Measurement (ARM) Aerial Facility (AAF), the BBOP deployed the Gulfstream-1 (G-1) aircraftmore » over smoke plumes from active wildfire and agricultural burns to help identify the impact of these events and how impacts evolve with time. BBOP was one of very few studies that targeted the near-field time evolution of aerosols and aimed to obtain a process-level understanding of the large changes that occur within a few hours of atmospheric processing.« less

Biomass Burning Emissions of Black Carbon from African Sources

NASA Astrophysics Data System (ADS)

Aiken, A. C.; Leone, O.; Nitschke, K. L.; Dubey, M. K.; Carrico, C.; Springston, S. R.; Sedlacek, A. J., III; Watson, T. B.; Kuang, C.; Uin, J.; McMeeking, G. R.; DeMott, P. J.; Kreidenweis, S. M.; Robinson, A. L.; Yokelson, R. J.; Zuidema, P.

2016-12-01

Biomass burning (BB) emissions are a large source of carbon to the atmosphere via particles and gas phase species. Carbonaceous aerosols are emitted along with gas-phase carbon monoxide (CO) and carbon dioxide (CO2) that can be used to determine particulate emission ratios and modified combustion efficiencies. Black carbon (BC) aerosols are potentially underestimated in global models and are considered to be one of the most important global warming factors behind CO2. Half or more BC in the atmosphere is from BB, estimated at 6-9 Tg/yr (IPCC, 5AR) and contributing up to 0.6 W/m2 atmospheric warming (Bond et al., 2013). With a potential rise in drought and extreme events in the future due to climate change, these numbers are expected to increase. For this reason, we focus on BC and organic carbon aerosol species that are emitted from forest fires and compare their emission ratios, physical and optical properties to those from controlled laboratory studies of single-source BB fuels to understand BB carbonaceous aerosols in the atmosphere. We investigate BC in concentrated BB plumes as sampled from the new U.S. DOE ARM Program campaign, Layered Atlantic Smoke Interactions with Clouds (LASIC). The ARM Aerosol Mobile Facility 1 (AMF1) and Mobile Aerosol Observing System (MAOS) are currently located on Ascension Island in the South Atlantic Ocean, located midway between Angola and Brazil. The location was chosen for sampling maximum aerosol outflow from Africa. The far-field aged BC from LASIC is compared to BC from indoor generation from single-source fuels, e.g. African grass, sampled during Fire Lab At Missoula Experiments IV (FLAME-IV). BC is measured with a single-particle soot photometer (SP2) alongside numerous supporting instrumentation, e.g. particle counters, CO and CO2 detectors, aerosol scattering and absorption measurements, etc. FLAME-IV includes both direct emissions and well-mixed aerosol samples that have undergone dilution, cooling, and condensation. BC physical and optical properties change as particles are transported in the atmosphere due to oxidation, coagulation, and condensation which is observed in the laboratory BC data. Laboratory BC emissions and emission ratios are compared with those from LASIC to improve model treatment of BB BC emissions and aging in global climate models.

Water vapor isotopic measurements from the Atmospheric Radiation Measurement site on Graciosa Island, Azores

NASA Astrophysics Data System (ADS)

Delp, J. M.; Galewsky, J.

2017-12-01

Stable isotopic measurements of water vapor can potentially constrain the processes that govern the formation of low-clouds and how their distribution may change as the climate warms. Using off-axis integrated cavity output spectroscopy, in-situ water vapor isotopic measurements will be collected for a period of one year (beginning August 2017) at the US Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) site in the Eastern North Atlantic (ENA) located on Graciosa Island, Azores. The Azores location within the ENA is a prime setting for studying low-cloud processes. After correcting for humidity-dependent biases and normalizing the measurements to the VSMOW-SLAP scale, the measurements from the first several months of the water vapor isotopic analyzer's deployment will be compared to complementary datasets from the suite of instruments at the DOE site, including twice-daily soundings, aerosol instrumentation, and cloud radars, with the purpose of determining links between local stratocumulus and precipitation processes and their impact on the stable isotopic composition of atmospheric water vapor. The results of this study will potentially provide a new approach for linking field observations with climate models and may help better constrain the uncertainties associated with low-cloud feedbacks.

Allometric associations between body size, shape, and 100-m butterfly speed performance.

PubMed

Sammoud, Senda; Nevill, Alan M; Negra, Yassine; Bouguezzi, Raja; Chaabene, Helmi; Hachana, Younés

2018-05-01

This study aimed to estimate the optimal body size, limb-segment length, and girth or breadth ratios associated with 100-m butterfly speed performance in swimmers. One-hundred-sixty-seven swimmers as subjects (male: N.=103; female: N.=64). Anthropometric measurements comprised height, body-mass, skinfolds, arm-span, upper-limb-length, upper-arm, forearm, hand-lengths, lower-limb-length, thigh-length, leg-length, foot-length, arm-relaxed-girth, forearm-girth, wrist-girth, thigh-girth, calf-girth, ankle-girth, biacromial and biiliocristal-breadths. To estimate the optimal body size and body composition components associated with 100-m butterfly speed performance, we adopted a multiplicative allometric log-linear regression model, which was refined using backward elimination. Fat-mass was the singularly most important whole-body characteristic. Height and body-mass did not contribute to the model. The allometric model identified that having greater limb segment length-ratio (arm-ratio = [arm-span]/[forearm]) and limb girth-ratio (girth-ratio = [calf-girth]/[ankle-girth]) were key to butterfly speed performance. A greater arm-span to forearm-length ratio and a greater calf to ankle-girth-ratio suggest that a combination of larger arm-span and shorter forearm-length and the combination of larger calves and smaller ankles-girth may benefit butterfly swim speed performance. In addition having greater biacromial and biliocristal breadths is also a major advantage in butterfly swimming speed performance. Finally, the estimation of these ratios was made possible by adopting a multiplicative allometric model that was able to confirm, theoretically, that swim speeds are nearly independent of total body size. The 100-m butterfly speed performance was strongly negatively associated with fat mass and positively associated with the segment length ratio (arm-span/forearm-length) and girth ratio (calf-girth)/(ankle-girth), having controlled for the developmental changes in age.

Optimal Body Size and Limb Length Ratios Associated with 100-m Personal-Best Swim Speeds.

PubMed

Nevill, Alan M; Oxford, Samuel W; Duncan, Michael J

2015-08-01

This study aims to identify optimal body size and limb segment length ratios associated with 100-m personal-best (PB) swim speeds in children and adolescents. Fifty national-standard youth swimmers (21 males and 29 females age 11-16 yr; mean ± SD age, 13.5 ± 1.5 yr) participated in the study. Anthropometry comprised stature; body mass; skinfolds; maturity offset; upper arm, lower arm, and hand lengths; and upper leg, lower leg, and foot lengths. Swimming performance was taken as the PB time recorded in competition for the 100-m freestyle swim. To identify the optimal body size and body composition components associated with 100-m PB swim speeds (having controlled for age and maturity offset), we adopted a multiplicative allometric log-linear regression model, which was refined using backward elimination. Lean body mass was the singularly most important whole-body characteristic. Stature and body mass did not contribute to the model, suggesting that the advantage of longer levers was limb-specific rather than a general whole-body advantage. The allometric model also identified that having greater limb segment length ratios [i.e., arm ratio = (low arm)/(upper arm); foot-to-leg ratio = (foot)/(lower leg)] was key to PB swim speeds. It is only by adopting multiplicative allometric models that the above mentioned ratios could have been derived. The advantage of having a greater lower arm is clear; however, having a shorter upper arm (achieved by adopting a closer elbow angle technique or by possessing a naturally endowed shorter upper arm), at the same time, is a new insight into swimming performance. A greater foot-to-lower-leg ratio suggests that a combination of larger feet and shorter lower leg length may also benefit PB swim speeds.

Determination of Cloud Base Height, Wind Velocity, and Short-Range Cloud Structure Using Multiple Sky Imagers Field Campaign Report

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

Huang, Dong; Schwartz, Stephen E.; Yu, Dantong

Clouds are a central focus of the U.S. Department of Energy (DOE)’s Atmospheric System Research (ASR) program and Atmospheric Radiation Measurement (ARM) Climate Research Facility, and more broadly are the subject of much investigation because of their important effects on atmospheric radiation and, through feedbacks, on climate sensitivity. Significant progress has been made by moving from a vertically pointing (“soda-straw”) to a three-dimensional (3D) view of clouds by investing in scanning cloud radars through the American Recovery and Reinvestment Act of 2009. Yet, because of the physical nature of radars, there are key gaps in ARM's cloud observational capabilities. Formore » example, cloud radars often fail to detect small shallow cumulus and thin cirrus clouds that are nonetheless radiatively important. Furthermore, it takes five to twenty minutes for a cloud radar to complete a 3D volume scan and clouds can evolve substantially during this period. Ground-based stereo-imaging is a promising technique to complement existing ARM cloud observation capabilities. It enables the estimation of cloud coverage, height, horizontal motion, morphology, and spatial arrangement over an extended area of up to 30 by 30 km at refresh rates greater than 1 Hz (Peng et al. 2015). With fine spatial and temporal resolution of modern sky cameras, the stereo-imaging technique allows for the tracking of a small cumulus cloud or a thin cirrus cloud that cannot be detected by a cloud radar. With support from the DOE SunShot Initiative, the Principal Investigator (PI)’s team at Brookhaven National Laboratory (BNL) has developed some initial capability for cloud tracking using multiple distinctly located hemispheric cameras (Peng et al. 2015). To validate the ground-based cloud stereo-imaging technique, the cloud stereo-imaging field campaign was conducted at the ARM Facility’s Southern Great Plains (SGP) site in Oklahoma from July 15 to December 24. As shown in Figure 1, the cloud stereo-imaging system consisted of two inexpensive high-definition (HD) hemispheric cameras (each cost less than $1,500) and ARM’s Total Sky Imager (TSI). Together with other co-located ARM instrumentation, the campaign provides a promising opportunity to validate stereo-imaging-based cloud base height and, more importantly, to examine the feasibility of cloud thickness retrieval for low-view-angle clouds.« less

The Effect of Central American Smoke Aerosols on the Air Quality and Climate over the Southeastern United States: First Results from RAMS-AROMA

NASA Astrophysics Data System (ADS)

Wang, J.; Christopher, S. A.; Nair, U. S.; Reid, J.; Prins, E. M.; Szykman, J.

2004-12-01

Observation shows that smoke aerosols from biomass burning activities in Central America can be transported to the Southeastern United States (SEUS). In this study, the Regional Atmospheric Modeling System - Assimilation and Radiation Online Modeling of Aerosols (RAMS-AROMA) is used to investigate the effect of transported smoke aerosols on climate and air quality over the SEUS. AROMA is an aerosol transport model with capabilities of online integration of aerosol radiation effects and online assimilation of satellite-derived aerosol and emission products. It is assembled within the RAMS, so two-way interactions between aerosol fields and other meteorology fields are achieved simultaneously during each model time step. RAMS-AROMA is a unique tool that can be used to examine the aerosol radiative impacts on the surface energy budget and atmospheric heating rate and to investigate how atmospheric thermal and dynamical processes respond to such impacts and consequently affect the aerosol distribution (so called feedbacks). First results regarding air quality effects and radiative forcing of transported smoke aerosols will be presented from RAMS-AROMA based on assimilation of smoke emission products from the Fire Locating and Modeling of Burning Emissions (FLAMBE) project and aerosol optical thickness data derived from the MODIS instrument on the Terra and Aqua satellites. Comparisons with PM2.5 data collected from the EPA observation network and the aerosol optical thickness data from the DOE Atmosphere Radiation Measurements in the Southern Great Plains (ARM SGP) showed that RAMS-AROMA can predict the timing and spatial distribution of smoke events very well, with an accuracy useful for air quality forecasts. The smoke radiative effects on the surface temperature and atmospheric heating rate as well as their feedbacks will also be discussed.

Regulation of BDNF Release by ARMS/Kidins220 through Modulation of Synaptotagmin-IV Levels.

PubMed

López-Benito, Saray; Sánchez-Sánchez, Julia; Brito, Verónica; Calvo, Laura; Lisa, Silvia; Torres-Valle, María; Palko, Mary E; Vicente-García, Cristina; Fernández-Fernández, Seila; Bolaños, Juan P; Ginés, Silvia; Tessarollo, Lino; Arévalo, Juan C

2018-06-06

BDNF is a growth factor with important roles in the nervous system in both physiological and pathological conditions, but the mechanisms controlling its secretion are not completely understood. Here, we show that ARMS/Kidins220 negatively regulates BDNF secretion in neurons from the CNS and PNS. Downregulation of the ARMS/Kidins220 protein in the adult mouse brain increases regulated BDNF secretion, leading to its accumulation in the striatum. Interestingly, two mouse models of Huntington's disease (HD) showed increased levels of ARMS/Kidins220 in the hippocampus and regulated BDNF secretion deficits. Importantly, reduction of ARMS/Kidins220 in hippocampal slices from HD mice reversed the impaired regulated BDNF release. Moreover, there are increased levels of ARMS/Kidins220 in the hippocampus and PFC of patients with HD. ARMS/Kidins220 regulates Synaptotagmin-IV levels, which has been previously observed to modulate BDNF secretion. These data indicate that ARMS/Kidins220 controls the regulated secretion of BDNF and might play a crucial role in the pathogenesis of HD. SIGNIFICANCE STATEMENT BDNF is an important growth factor that plays a fundamental role in the correct functioning of the CNS. The secretion of BDNF must be properly controlled to exert its functions, but the proteins regulating its release are not completely known. Using neuronal cultures and a new conditional mouse to modulate ARMS/Kidins220 protein, we report that ARMS/Kidins220 negatively regulates BDNF secretion. Moreover, ARMS/Kidins220 is overexpressed in two mouse models of Huntington's disease (HD), causing an impaired regulation of BDNF secretion. Furthermore, ARMS/Kidins220 levels are increased in brain samples from HD patients. Future studies should address whether ARMS/Kidins220 has any function on the pathophysiology of HD. Copyright © 2018 the authors 0270-6474/18/385415-14$15.00/0.

How do deltoid muscle moment arms change after reverse total shoulder arthroplasty?

PubMed

Walker, David R; Struk, Aimee M; Matsuki, Keisuke; Wright, Thomas W; Banks, Scott A

2016-04-01

Although many advantages of reverse total shoulder arthroplasty (RTSA) have been demonstrated, a variety of complications indicate there is much to learn about how RTSA modifies normal shoulder function. This study used a subject-specific computational model driven by in vivo kinematic data to assess how RTSA affects deltoid muscle moment arms after surgery. A subject-specific 12 degree-of-freedom musculoskeletal model was used to analyze the shoulders of 26 individuals (14 RTSA and 12 normal). The model was modified from the work of Holzbaur to directly input 6 degree-of-freedom humeral and scapular kinematics obtained using fluoroscopy. The moment arms of the anterior, lateral, and posterior aspects of the deltoid were significantly different when RTSA and normal cohorts were compared at different abduction angles. Anterior and lateral deltoid moment arms were significantly larger in the RTSA group at the initial elevation of the arm. The posterior deltoid was significantly larger at maximum elevation. There was large intersubject variability within the RTSA group. Placement of implant components during RTSA can directly affect the geometric relationship between the humerus and scapula and the muscle moment arms in the RTSA shoulder. RTSA shoulders maintain the same anterior and posterior deltoid muscle moment-arm patterns as healthy shoulders but show much greater intersubject variation and larger moment-arm magnitudes. These observations provide a basis for determining optimal implant configuration and surgical placement to maximize RTSA function in a patient-specific manner. Published by Elsevier Inc.

Cloud Property Retrieval Products for Graciosa Island, Azores

DOE Data Explorer

Dong, Xiquan

2014-05-05

The motivation for developing this product was to use the Dong et al. 1998 method to retrieve cloud microphysical properties, such as cloud droplet effective radius, cloud droplets number concentration, and optical thickness. These retrieved properties have been used to validate the satellite retrieval, and evaluate the climate simulations and reanalyses. We had been using this method to retrieve cloud microphysical properties over ARM SGP and NSA sites. We also modified the method for the AMF at Shouxian, China and some IOPs, e.g. ARM IOP at SGP in March, 2000. The ARSCL data from ARM data archive over the SGP and NSA have been used to determine the cloud boundary and cloud phase. For these ARM permanent sites, the ARSCL data was developed based on MMCR measurements, however, there were no data available at the Azores field campaign. We followed the steps to generate this derived product and also include the MPLCMASK cloud retrievals to determine the most accurate cloud boundaries, including the thin cirrus clouds that WACR may under-detect. We use these as input to retrieve the cloud microphysical properties. Due to the different temporal resolutions of the derived cloud boundary heights product and the cloud properties product, we submit them as two separate netcdf files.

Advances in Data Management in Remote Sensing and Climate Modeling

NASA Astrophysics Data System (ADS)

Brown, P. G.

2014-12-01

Recent commercial interest in "Big Data" information systems has yielded little more than a sense of deja vu among scientists whose work has always required getting their arms around extremely large databases, and writing programs to explore and analyze it. On the flip side, there are some commercial DBMS startups building "Big Data" platform using techniques taken from earth science, astronomy, high energy physics and high performance computing. In this talk, we will introduce one such platform; Paradigm4's SciDB, the first DBMS designed from the ground up to combine the kinds of quality-of-service guarantees made by SQL DBMS platforms—high level data model, query languages, extensibility, transactions—with the kinds of functionality familiar to scientific users—arrays as structural building blocks, integrated linear algebra, and client language interfaces that minimize the learning curve. We will review how SciDB is used to manage and analyze earth science data by several teams of scientific users.

Calculation of ground vibration spectra from heavy military vehicles

NASA Astrophysics Data System (ADS)

Krylov, V. V.; Pickup, S.; McNuff, J.

2010-07-01

The demand for reliable autonomous systems capable to detect and identify heavy military vehicles becomes an important issue for UN peacekeeping forces in the current delicate political climate. A promising method of detection and identification is the one using the information extracted from ground vibration spectra generated by heavy military vehicles, often termed as their seismic signatures. This paper presents the results of the theoretical investigation of ground vibration spectra generated by heavy military vehicles, such as tanks and armed personnel carriers. A simple quarter car model is considered to identify the resulting dynamic forces applied from a vehicle to the ground. Then the obtained analytical expressions for vehicle dynamic forces are used for calculations of generated ground vibrations, predominantly Rayleigh surface waves, using Green's function method. A comparison of the obtained theoretical results with the published experimental data shows that analytical techniques based on the simplified quarter car vehicle model are capable of producing ground vibration spectra of heavy military vehicles that reproduce basic properties of experimental spectra.

Rasp Tool on Phoenix Robotic Arm Model

NASA Image and Video Library

2008-07-15

This close-up photograph taken at the Payload Interoperability Testbed at the University of Arizona, Tucson, shows the motorized rasp protruding from the bottom of the scoop on the engineering model of NASA Phoenix Mars Lander Robotic Arm.

Influence of Forced Flow on the Dendritic Growth of Fe-C Alloy: 3D vs 2D Simulation

NASA Astrophysics Data System (ADS)

Wang, Weiling; Wang, Zhaohui; Luo, Sen; Ji, Cheng; Zhu, Miaoyong

2017-12-01

A 3D parallel cellular automaton-finite volume method (CA-FVM) model was used to simulate the equiaxed dendritic growth of an Fe-0.82 wt pct C alloy with xy- in- out and xyz- in- out type forced flows and the columnar dendritic growth with y- in- out type forced flow. In addition, the similarities and differences between the results of the 3D and 2D models are discussed and summarized in detail. The capabilities of the 3D and 2D CA-FVM models to predict the dendritic growth of the alloy with forced flow are validated through comparison with the boundary layer correction and Oseen-Ivanstov models, respectively. Because the forced flow can pass around perpendicular arms of the dendrites, the secondary arms at the sides upstream from the perpendicular arms are more developed than those on the upstream side of the upstream arms, especially at higher inlet velocities. In addition, compared to the xy- in- out case, the growth of the downstream arms is less inhibited and the secondary arms are more developed in the xyz- in- out case because of the greater lateral flow around their tips. Compared to the 3D case, the 2D equiaxed dendrites are more asymmetrical and lack secondary arms because of the thicker solute envelope. In the 3D case, the columnar dendrites on the upstream side (left one) are promoted, while the middle and downstream dendrites are inhibited in sequence. However, the sequential inhibition starts on the upstream side in the 2D case. This is mainly because the melt can pass around the upstream branch in 3D space. However, it can only climb over the upstream tip in 2D space. Additionally, the secondary arms show upstream development, which is more significant with increasing inlet velocity. The level of development of the secondary arms is also affected by the decay of the forced flow in the flow direction.

Control method and system for hydraulic machines employing a dynamic joint motion model

DOEpatents

Danko, George [Reno, NV

2011-11-22

A control method and system for controlling a hydraulically actuated mechanical arm to perform a task, the mechanical arm optionally being a hydraulically actuated excavator arm. The method can include determining a dynamic model of the motion of the hydraulic arm for each hydraulic arm link by relating the input signal vector for each respective link to the output signal vector for the same link. Also the method can include determining an error signal for each link as the weighted sum of the differences between a measured position and a reference position and between the time derivatives of the measured position and the time derivatives of the reference position for each respective link. The weights used in the determination of the error signal can be determined from the constant coefficients of the dynamic model. The error signal can be applied in a closed negative feedback control loop to diminish or eliminate the error signal for each respective link.

New Cloud Science from the New ARM Cloud Radar Systems (Invited)

NASA Astrophysics Data System (ADS)

Wiscombe, W. J.

2010-12-01

The DOE ARM Program is deploying over $30M worth of scanning polarimetric Doppler radars at its four fixed and two mobile sites, with the object of advancing cloud lifecycle science, and cloud-aerosol-precipitation interaction science, by a quantum leap. As of 2011, there will be 13 scanning radar systems to complement its existing array of profiling cloud radars: C-band for precipitation, X-band for drizzle and precipitation, and two-frequency radars for cloud droplets and drizzle. This will make ARM the world’s largest science user of, and largest provider of data from, ground-based cloud radars. The philosophy behind this leap is actually quite simple, to wit: dimensionality really does matter. Just as 2D turbulence is fundamentally different from 3D turbulence, so observing clouds only at zenith provides a dimensionally starved, and sometimes misleading, picture of real clouds. In particular, the zenith view can say little or nothing about cloud lifecycle and the second indirect effect, nor about aerosol-precipitation interactions. It is not even particularly good at retrieving the cloud fraction (no matter how that slippery quantity is defined). This talk will review the history that led to this development and then discuss the aspirations for how this will propel cloud-aerosol-precipitation science forward. The step by step plan for translating raw radar data into information that is useful to cloud and aerosol scientists and climate modelers will be laid out, with examples from ARM’s recent scanning cloud radar deployments in the Azores and Oklahoma . In the end, the new systems should allow cloud systems to be understood as 4D coherent entities rather than dimensionally crippled 2D or 3D entities such as observed by satellites and zenith-pointing radars.

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

Schumacher, Courtney

One of the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s Parsivel2 disdrometers was deployed at the first ARM Mobile Facility (AMF1) T3 site in Manacapuru, Brazil at the beginning of the second Green Ocean Amazon (GoAmazon)2014/15 intensive operational period (IOP2) in September 2014 through the end of the field campaign in December 2015. The Parsivel2 provided one-minute drop-size distribution (DSD) observations that have already been used for a number of applications related to GoAmazon2014/15 science objectives. The first use was the creation of a reflectivity-rain rate (Z-R) relation enabling the calculation of rain rates frommore » the Brazilian Sistema de Protecao da Amazonia (SIPAM) S-band operational radar in Manaus. The radar-derived rainfall is an important constraint for the variational analysis of a large-scale forcing data set, which was recently released for the two IOPs that took place in the 2014 wet and transition seasons, respectively. The SIPAM radar rainfall is also being used to validate a number of cloud-resolving model simulations being run for the campaign. A second use of the Parsivel2 DSDs has been to provide a necessary reference point to calibrate the vertical velocity retrievals from the AMF1 W Band ARM Cloud Radar (WACR) cloud-profiling and ultra-high-frequency (UHF) wind-profiling instruments. Accurate retrievals of in-cloud vertical velocities are important to understand the microphysical and kinematic properties of Amazonian convective clouds and their interaction with the land surface and atmospheric aerosols. Further use of the Parsivel2 DSD observations can be made to better understand precipitation characteristics and their variability during GoAmazon2014/15.« less

The Transcriptional Coactivator TAZ Is a Potent Mediator of Alveolar Rhabdomyosarcoma Tumorigenesis.

PubMed

Deel, Michael D; Slemmons, Katherine K; Hinson, Ashley R; Genadry, Katia C; Burgess, Breanne A; Crose, Lisa E S; Kuprasertkul, Nina; Oristian, Kristianne M; Bentley, Rex C; Linardic, Corinne M

2018-03-07

Purpose: Alveolar rhabdomyosarcoma (aRMS) is a childhood soft tissue sarcoma driven by the signature PAX3-FOXO1 (P3F) fusion gene. Five-year survival for aRMS is <50%, with no improvement in over 4 decades. Although the transcriptional coactivator TAZ is oncogenic in carcinomas, the role of TAZ in sarcomas is poorly understood. The aim of this study was to investigate the role of TAZ in P3F-aRMS tumorigenesis. Experimental Design: After determining from publicly available datasets that TAZ is upregulated in human aRMS transcriptomes, we evaluated whether TAZ is also upregulated in our myoblast-based model of P3F-initiated tumorigenesis, and performed IHC staining of 63 human aRMS samples from tissue microarrays. Using constitutive and inducible RNAi, we examined the impact of TAZ loss of function on aRMS oncogenic phenotypes in vitro and tumorigenesis in vivo Finally, we performed pharmacologic studies in aRMS cell lines using porphyrin compounds, which interfere with TAZ-TEAD transcriptional activity. Results: TAZ is upregulated in our P3F-initiated aRMS model, and aRMS cells and tumors have high nuclear TAZ expression. In vitro , TAZ suppression inhibits aRMS cell proliferation, induces apoptosis, supports myogenic differentiation, and reduces aRMS cell stemness. TAZ-deficient aRMS cells are enriched in G 2 -M phase of the cell cycle. In vivo , TAZ suppression attenuates aRMS xenograft tumor growth. Preclinical studies show decreased aRMS xenograft tumor growth with porphyrin compounds alone and in combination with vincristine. Conclusions: TAZ is oncogenic in aRMS sarcomagenesis. While P3F is currently not therapeutically tractable, targeting TAZ could be a promising novel approach in aRMS. Clin Cancer Res; 1-15. ©2018 AACR. ©2018 American Association for Cancer Research.

Tower Temperature and Humidity Sensors (TWR) Handbook

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

Cook, DR

2010-02-01

Three tall towers are installed at the Atmospheric Radiation Measurement (ARM) Climate Research Facility: a 60-meter triangular tower at the Southern Great Plains (SGP) Central Facility (CF), a 21-meter walkup scaffolding tower at the SGP Okmulgee forest site (E21), and a 40-meter triangular tower at the North Slope of Alaska (NSA) Barrow site. The towers are used for meteorological, radiological, and other measurements.

Diversity, Inclusion, and Equal Opportunity in the Armed Services: Background and Issues for Congress

DTIC Science & Technology

2016-07-01

from unlawful discrimination based on race, color, national origin, religion, sex (including pregnancy , gender identity, and sexual orientation when...range of online resources for diversity management and equal opportunity programming. DEOMI’s Research Directorate administers a survey called the...Defense Equal Opportunity Climate Survey (DEOCS). This survey is intended to be a tool for commanders to improve their organizational culture. It

ACRF Instrumentation Status: New, Current, and Future - October – November 2007

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

JW Voyles

2007-11-30

The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) instrumentation status. The report is divided into the following four sections: (1) new instrumentation in the process of being acquired and deployed, (2) existing instrumentation and progress on improvements or upgrades, (3) proposed future instrumentation, and (4) SBIR instrument development.

Rock Magnetic Cyclostratigraphy of the Mid-Cretaceous Greenhorn Limestone, South-Central Colorado---Influence of Orbitally Induced Climate Variability for Chornostratigraphy

NASA Astrophysics Data System (ADS)

Sellers, T.; Geissman, J. W.; Jackson, J.

2015-12-01

We are testing the hypothesis that depositional processes of the mid-Cretaceous Greenhorn Limestone were influenced by orbitally-driven climate variations using rock magnetic data. Correlation of the data, including anhysteretic remanent magnetization (ARM), magnetic susceptibility, isothermal remanent magnetization in different DC fields to saturation, and hysteresis properties, from three continuously exposed sections of the full Greenhorn Limestone provides detailed spatial distribution for the depositional processes and magnetic mineral climate encoding. The Greenhorn Limestone includes the Lincoln Limestone, Hartland Shale, and the Bridge Creek Limestone members and consists of calcareous shales and limestones representing near maximum depths in the Cretaceous interior seaway. The sections, each about 30 m thick, extend from the upper Graneros Shale, through the Greenhorn Formation, to the lower Carlisle Shale, with samples collected at a two to five cm interval and are located at Badito, CO; north of Redwing, CO; and at the Global boundary Stratotype Section and Point (GSSP) at Lake Pueblo, CO. Our over 1000 samples were hand crushed to granule size pieces and packed into 7cc IODP boxes. Bulk magnetic susceptibility, anhysteretic remanent magnetization (ARM) intensity at different peak AF levels, and isothermal remanent magnetization (IRM) intensity record variations in magnetic mineral concentration and are proxies to determine orbital scale cycles and precise stratigraphic correlation between sections. ARM intensities in a peak field of 100 mT at both sites range between 1.2 x 10-3 and 1.3 x 10-4 A/m and better define periodic variation within the Greenhorn Limestone displaying differences in ferromagnetic mineral content of detrital origin. Magnetic susceptibility, which ranges from 3.5 x 10-2 to 2.86 x 10-3, also shows periodic variation with a strong correlation among the three sections. Saturation IRM at 100 mT ranges from 3.2 x 10-1 to 1.1x 10-2 A/m shows periodic variation with the greatest variability in the Bridge Creek Member. Preliminary spectral analysis of each data set indicates a dominant cyclicity that is of considerably lower frequency than the limestone/shale couplets characteristic of Greenhorn Limestone.

Cloud Condensation Nuclei Particle Counter (CCN) Instrument Handbook

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

Uin, Janek

2016-04-01

The Cloud Condensation Nuclei Counter—CCN (Figure 1) is a U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility instrument for measuring the concentration of aerosol particles that can act as cloud condensation nuclei [1, 2]. The CCN draws the sample aerosol through a column with thermodynamically unstable supersaturated water vapor that can condense onto aerosol particles. Particles that are activated, i.e., grown larger in this process, are counted (and sized) by an Optical Particle Counter (OPC). Thus, activated ambient aerosol particle number concentration as a function of supersaturation is measured. Models CCN-100 and CCN-200 differ only inmore » the number of humidifier columns and related subsystems: CCN-100 has one column and CCN-200 has two columns along with dual flow systems and electronics.« less

Committee ARM User Executive Committee Meeting Summary March 30-31, 2016

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

None, None

This meeting was held at the National Center for Atmospheric Research (NCAR) Mesa Lab, Boulder, Colorado. Atmospheric Radiation Measurement (ARM) Climate Research Facility User Executive Committee (UEC) members present were: Chuck Long, Ernie Lewis, Larry Berg, Hailong Wang, Matt Shupe, Andrew Gettelman, and Dave Turner. Rob Wood joined the discussion at several points via conference call, as he was unable to attend in person. Gannet Hallar and Pavlos Kollias were unable to attend. ARM Infrastructure members present were: Jim Mather, Jennifer Comstock, Jimmy Voyles, Ken Kehoe, Doug Sisterson, Hanna Goss, and Giri Prakash. The ARM UEC met face to facemore » for the first time since the committee was formed in December, 2014 at the NCAR Mesa Lab in Boulder. Prior to this point, all UEC meetings were done via telephone, usually with the aid of collaboration software (e.g., Lync, GoToMeeting) allowing the entire committee to see a common presentation. These conference calls covered a wide range of topics, many of them on a recurrent basis; however, since the calls were limited to less than 90 minutes it was felt that a more dedicated meeting would allow us to delve more deeply into some of these topics. Three topics for this meeting came from previous conference call discussions: (1) data quality, (2) uncertainty quantification, and (3) improved communications. Two other topics were discussed during this meeting: (4) an overview of the LES (large-eddy simulation) ARM Symbiotic Simulation and Observation (LASSO) project and (5) the process for electing new UEC members. Summaries of each of these topics are provided below, along with recommendations that the UEC feels should be considered by the ARM Facility (which will be highlighted using italics).« less

Improving Mixed-phase Cloud Parameterization in Climate Model with the ACRF Measurements

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

Wang, Zhien

Mixed-phase cloud microphysical and dynamical processes are still poorly understood, and their representation in GCMs is a major source of uncertainties in overall cloud feedback in GCMs. Thus improving mixed-phase cloud parameterizations in climate models is critical to reducing the climate forecast uncertainties. This study aims at providing improved knowledge of mixed-phase cloud properties from the long-term ACRF observations and improving mixed-phase clouds simulations in the NCAR Community Atmosphere Model version 5 (CAM5). The key accomplishments are: 1) An improved retrieval algorithm was developed to provide liquid droplet concentration for drizzling or mixed-phase stratiform clouds. 2) A new ice concentrationmore » retrieval algorithm for stratiform mixed-phase clouds was developed. 3) A strong seasonal aerosol impact on ice generation in Arctic mixed-phase clouds was identified, which is mainly attributed to the high dust occurrence during the spring season. 4) A suite of multi-senor algorithms was applied to long-term ARM observations at the Barrow site to provide a complete dataset (LWC and effective radius profile for liquid phase, and IWC, Dge profiles and ice concentration for ice phase) to characterize Arctic stratiform mixed-phase clouds. This multi-year stratiform mixed-phase cloud dataset provides necessary information to study related processes, evaluate model stratiform mixed-phase cloud simulations, and improve model stratiform mixed-phase cloud parameterization. 5). A new in situ data analysis method was developed to quantify liquid mass partition in convective mixed-phase clouds. For the first time, we reliably compared liquid mass partitions in stratiform and convective mixed-phase clouds. Due to the different dynamics in stratiform and convective mixed-phase clouds, the temperature dependencies of liquid mass partitions are significantly different due to much higher ice concentrations in convective mixed phase clouds. 6) Systematic evaluations of mixed-phase cloud simulations by CAM5 were performed. Measurement results indicate that ice concentrations control stratiform mixed-phase cloud properties. The improvement of ice concentration parameterization in the CAM5 was done in close collaboration with Dr. Xiaohong Liu, PNNL (now at University of Wyoming).« less

Evaluation of WRF physical parameterizations against ARM/ASR Observations in the post-cold-frontal region to improve low-level clouds representation in CAM5

NASA Astrophysics Data System (ADS)

Lamraoui, F.; Booth, J. F.; Naud, C. M.

2017-12-01

The representation of subgrid-scale processes of low-level marine clouds located in the post-cold-frontal region poses a serious challenge for climate models. More precisely, the boundary layer parameterizations are predominantly designed for individual regimes that can evolve gradually over time and does not accommodate the cold front passage that can overly modify the boundary layer rapidly. Also, the microphysics schemes respond differently to the quick development of the boundary layer schemes, especially under unstable conditions. To improve the understanding of cloud physics in the post-cold frontal region, the present study focuses on exploring the relationship between cloud properties, the local processes and large-scale conditions. In order to address these questions, we explore the WRF sensitivity to the interaction between various combinations of the boundary layer and microphysics parameterizations, including the Community Atmospheric Model version 5 (CAM5) physical package in a perturbed physics ensemble. Then, we evaluate these simulations against ground-based ARM observations over the Azores. The WRF-based simulations demonstrate particular sensitivities of the marine cold front passage and the associated post-cold frontal clouds to the domain size, the resolution and the physical parameterizations. First, it is found that in multiple different case studies the model cannot generate the cold front passage when the domain size is larger than 3000 km2. Instead, the modeled cold front stalls, which shows the importance of properly capturing the synoptic scale conditions. The simulation reveals persistent delay in capturing the cold front passage and also an underestimated duration of the post-cold-frontal conditions. Analysis of the perturbed physics ensemble shows that changing the microphysics scheme leads to larger differences in the modeled clouds than changing the boundary layer scheme. The in-cloud heating tendencies are analyzed to explain this sensitivity.

The Python ARM Radar Toolkit (Py-ART), a library for working with weather radar data in the Python programming language

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

Helmus, Jonathan J.; Collis, Scott M.

The Python ARM Radar Toolkit is a package for reading, visualizing, correcting and analysing data from weather radars. Development began to meet the needs of the Atmospheric Radiation Measurement Climate Research Facility and has since expanded to provide a general-purpose framework for working with data from weather radars in the Python programming language. The toolkit is built on top of libraries in the Scientific Python ecosystem including NumPy, SciPy, and matplotlib, and makes use of Cython for interfacing with existing radar libraries written in C and to speed up computationally demanding algorithms. As a result, the source code for themore » toolkit is available on GitHub and is distributed under a BSD license.« less

The Python ARM Radar Toolkit (Py-ART), a library for working with weather radar data in the Python programming language

DOE PAGES

Helmus, Jonathan J.; Collis, Scott M.

2016-07-18

The Python ARM Radar Toolkit is a package for reading, visualizing, correcting and analysing data from weather radars. Development began to meet the needs of the Atmospheric Radiation Measurement Climate Research Facility and has since expanded to provide a general-purpose framework for working with data from weather radars in the Python programming language. The toolkit is built on top of libraries in the Scientific Python ecosystem including NumPy, SciPy, and matplotlib, and makes use of Cython for interfacing with existing radar libraries written in C and to speed up computationally demanding algorithms. As a result, the source code for themore » toolkit is available on GitHub and is distributed under a BSD license.« less

Learning visuomotor transformations for gaze-control and grasping.

PubMed

Hoffmann, Heiko; Schenck, Wolfram; Möller, Ralf

2005-08-01

For reaching to and grasping of an object, visual information about the object must be transformed into motor or postural commands for the arm and hand. In this paper, we present a robot model for visually guided reaching and grasping. The model mimics two alternative processing pathways for grasping, which are also likely to coexist in the human brain. The first pathway directly uses the retinal activation to encode the target position. In the second pathway, a saccade controller makes the eyes (cameras) focus on the target, and the gaze direction is used instead as positional input. For both pathways, an arm controller transforms information on the target's position and orientation into an arm posture suitable for grasping. For the training of the saccade controller, we suggest a novel staged learning method which does not require a teacher that provides the necessary motor commands. The arm controller uses unsupervised learning: it is based on a density model of the sensor and the motor data. Using this density, a mapping is achieved by completing a partially given sensorimotor pattern. The controller can cope with the ambiguity in having a set of redundant arm postures for a given target. The combined model of saccade and arm controller was able to fixate and grasp an elongated object with arbitrary orientation and at arbitrary position on a table in 94% of trials.

Comprehensive quantitative investigation of arm swing during walking at various speed and surface slope conditions.

PubMed

Hejrati, Babak; Chesebrough, Sam; Bo Foreman, K; Abbott, Jake J; Merryweather, Andrew S

2016-10-01

Previous studies have shown that inclusion of arm swing in gait rehabilitation leads to more effective walking recovery in patients with walking impairments. However, little is known about the correct arm-swing trajectories to be used in gait rehabilitation given the fact that changes in walking conditions affect arm-swing patterns. In this paper we present a comprehensive look at the effects of a variety of conditions on arm-swing patterns during walking. The results describe the effects of surface slope, walking speed, and physical characteristics on arm-swing patterns in healthy individuals. We propose data-driven mathematical models to describe arm-swing trajectories. Thirty individuals (fifteen females and fifteen males) with a wide range of height (1.58-1.91m) and body mass (49-98kg), participated in our study. Based on their self-selected walking speed, each participant performed walking trials with four speeds on five surface slopes while their whole-body kinematics were recorded. Statistical analysis showed that walking speed, surface slope, and height were the major factors influencing arm swing during locomotion. The results demonstrate that data-driven models can successfully describe arm-swing trajectories for normal gait under varying walking conditions. The findings also provide insight into the behavior of the elbow during walking. Copyright © 2016. Published by Elsevier B.V.

AmeriFlux Measurement Component (AMC) Handbook

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

Reichl, K.; Biraud, S. C.

An AMC system was installed at the Atmospheric Radiation Measurement (ARM) Climate Research Facility’s North Slope Alaska (NSA) Barrow site, also known as NSA C1 at the ARM Data Archive, in August 2012. A second AMC system was installed at the third ARM Mobile Facility deployment at Oliktok Point, also known as NSA M1. This in situ system consists of 12 combination soil temperature and volumetric water content (VWC) reflectometers and one set of upwelling and downwelling PAR sensors, all deployed within the fetch of the Eddy Correlation Flux Measurement System. Soil temperature and VWC sensors placed at two depthsmore » (10 and 30 cm below the vegetation layer) at six locations (or microsites) allow soil property inhomogeneity to be monitored across a landscape. The soil VWC and temperature sensors used at NSA C1 are the Campbell Scientific CS650L and the sensors at NSA M1 use the Campbell Scientific CS655. The two sensors are nearly identical in function, and vendor specifications are based on the CS650 unless otherwise stated.« less

WHAT IS A MOMENT ARM? CALCULATING MUSCLE EFFECTIVENESS IN BIOMECHANICAL MODELS USING GENERALIZED COORDINATES

PubMed Central

Seth, Ajay; Delp, Scott L.

2015-01-01

Biomechanics researchers often use multibody models to represent biological systems. However, the mapping from biology to mechanics and back can be problematic. OpenSim is a popular open source tool used for this purpose, mapping between biological specifications and an underlying generalized coordinate multibody system called Simbody. One quantity of interest to biomechanical researchers and clinicians is “muscle moment arm,” a measure of the effectiveness of a muscle at contributing to a particular motion over a range of configurations. OpenSim can automatically calculate these quantities for any muscle once a model has been built. For simple cases, this calculation is the same as the conventional moment arm calculation in mechanical engineering. But a muscle may span several joints (e.g., wrist, neck, back) and may follow a convoluted path over various curved surfaces. A biological joint may require several bodies or even a mechanism to accurately represent in the multibody model (e.g., knee, shoulder). In these situations we need a careful definition of muscle moment arm that is analogous to the mechanical engineering concept, yet generalized to be of use to biomedical researchers. Here we present some biomechanical modeling challenges and how they are resolved in OpenSim and Simbody to yield biologically meaningful muscle moment arms. PMID:25905111

WHAT IS A MOMENT ARM? CALCULATING MUSCLE EFFECTIVENESS IN BIOMECHANICAL MODELS USING GENERALIZED COORDINATES.

PubMed

Sherman, Michael A; Seth, Ajay; Delp, Scott L

2013-08-01

Biomechanics researchers often use multibody models to represent biological systems. However, the mapping from biology to mechanics and back can be problematic. OpenSim is a popular open source tool used for this purpose, mapping between biological specifications and an underlying generalized coordinate multibody system called Simbody. One quantity of interest to biomechanical researchers and clinicians is "muscle moment arm," a measure of the effectiveness of a muscle at contributing to a particular motion over a range of configurations. OpenSim can automatically calculate these quantities for any muscle once a model has been built. For simple cases, this calculation is the same as the conventional moment arm calculation in mechanical engineering. But a muscle may span several joints (e.g., wrist, neck, back) and may follow a convoluted path over various curved surfaces. A biological joint may require several bodies or even a mechanism to accurately represent in the multibody model (e.g., knee, shoulder). In these situations we need a careful definition of muscle moment arm that is analogous to the mechanical engineering concept, yet generalized to be of use to biomedical researchers. Here we present some biomechanical modeling challenges and how they are resolved in OpenSim and Simbody to yield biologically meaningful muscle moment arms.

Mass Extinction and the Structure of the Milky Way

NASA Astrophysics Data System (ADS)

Filipovic, M. D.; Horner, J.; Crawford, E. J.; Tothill, N. F. H.; White, G. L.

2013-12-01

We use the most up-to-date Milky Way model and solar orbit data in order to test the hypothesis that the Sun's galactic spiral arm crossings cause mass extinction events on Earth. To do this, we created a new model of the Milky Way's spiral arms by combining a large quantity of data from several surveys. We then combined this model with a recently derived solution for the solar orbit to determine the timing of the Sun's historical passages through the Galaxy's spiral arms. Our new model was designed with a symmetrical appearance, with the major alteration being the addition of a spur at the far side of the Galaxy. A correlation was found between the times at which the Sun crosses the spiral arms and six known mass extinction events. Furthermore, we identify five additional historical mass extinction events that might be explained by the motion of the Sun around our Galaxy. These five additional significant drops in marine genera that we find include significant reductions in diversity at 415, 322, 300, 145 and 33~Myr ago. Our simulations indicate that the Sun has spent ˜60 per cent of its time passing through our Galaxy's various spiral arms. Also, we briefly discuss and combine previous work on the Galactic Habitable Zone with the new Milky Way model.

Models of anxiety: responses of mice to novelty and open spaces in a 3D maze.

PubMed

Ennaceur, A; Michalikova, S; van Rensburg, R; Chazot, P L

2006-11-01

The present report describes the emotional responses of different strains of mice to exposure to a novel open space model of anxiety using a 3D spatial navigation task. The 3D maze is modification of the radial maze with flexible arms that can be raised above or lowered below the horizontal level of a central platform. To access the arms animals need to cross a bridge linking the arms to the central platform. In this model, mice are exposed to novelty in an unfamiliar open space setting with no safe alternative. Fear from novelty is compounded with the need to explore. The drive to escape and the drive to approach are intermingled making this open space model radically different from the current models of anxiety which provide animals with the choice between safe and anxiogenic spaces. In a series of experiments, we examined the behaviour of different groups of mice from C57, C3H, CD1 and Balb/c strains. In the first experiment, different groups of C57 mice were tested in one of the three arms configurations. In the second experiment, C57 mice were compared to C3H mice. In the third experiment, C57 mice were compared to CD1 and Balb/c mice in the raised arm configuration over three successive sessions. In the fourth experiment, we examined the behaviour of C57 mice in the lowered arm configuration with an open and an enclosed central. In the final experiment, we examined the difference between C57 and C3H mice of both genders. Using several spatio-temporal parameters of the transition responses between central platform, bridges and arms, we have been able to show consistent results demonstrating significant differences between C57 and C3H mice, and between Balb/c and both C57 and CD1 mice. C3H appear more anxious than C57 mice, and Balb/c mice seem more anxious than C57 and CD1 mice. We also observed significant differences between sexes in C3H mice but not in C57 mice. C3H male mice appear more anxious than C3H female mice and than both C57 male and female mice. In the lowered arm configuration with an enclosed central platform, C57 mice took longer time to make a first entry to an arm, made more visits to bridges before first entry to an arm and required longer time between re-entries to arms, spent longer time on the central platform and shorter time on arms compared to mice in the other arm configurations. They also made frequent entries to the centre and bridges compared to mice in the lowered arm with an open central platform. These results demonstrate not only the sensitivity of the parameters of the test but also the consistencies and concordances of the results which make this 3D maze a valuable new tool in the study of the underlying neural mechanisms of anxiety responses in addition to learning and memory, and in assessing the effects of potential anxiolytic drugs. In this report we examine methodological issues related to the design of animal behavioural paradigms and question the value and the construct validity of the current models of human anxiety.

Use of ARM observations and numerical models to determine radiative and latent heating profiles of mesoscale convective systems for general circulation models

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

Tao, Wei-Kuo; Houze, Robert, A., Jr.; Zeng, Xiping

This three-year project, in cooperation with Professor Bob Houze at University of Washington, has been successfully finished as planned. Both ARM (the Atmospheric Radiation Measurement Program) data and cloud-resolving model (CRM) simulations were used to identify the water budgets of clouds observed in two international field campaigns. The research results achieved shed light on several key processes of clouds in climate change (or general circulation models), which are summarized below. 1. Revealed the effect of mineral dust on mesoscale convective systems (MCSs) Two international field campaigns near a desert and a tropical coast provided unique data to drive and evaluatemore » CRM simulations, which are TWP-ICE (the Tropical Warm Pool International Cloud Experiment) and AMMA (the African Monsoon Multidisciplinary Analysis). Studies of the two campaign data were contrasted, revealing that much mineral dust can bring about large MCSs via ice nucleation and clouds. This result was reported as a PI presentation in the 3rd ASR Science Team meeting held in Arlington, Virginia in March 2012. A paper on the studies was published in the Journal of the Atmospheric Sciences (Zeng et al. 2013). 2. Identified the effect of convective downdrafts on ice crystal concentration Using the large-scale forcing data from TWP-ICE, ARM-SGP (the Southern Great Plains) and other field campaigns, Goddard CRM simulations were carried out in comparison with radar and satellite observations. The comparison between model and observations revealed that convective downdrafts could increase ice crystal concentration by up to three or four orders, which is a key to quantitatively represent the indirect effects of ice nuclei, a kind of aerosol, on clouds and radiation in the Tropics. This result was published in the Journal of the Atmospheric Sciences (Zeng et al. 2011) and summarized in the DOE/ASR Research Highlights Summaries (see http://www.arm.gov/science/highlights/RMjY5/view). 3. Used radar observations to evaluate model simulations In cooperation with Profs. Bob Houze at University of Washington and Steven Rutledge at Colorado State University, numerical model results were evaluated with observations from W- and C-band radars and CloudSat/TRMM satellites. These studies exhibited some shortcomings of current numerical models, such as too little of thin anvil clouds, directing the future improvement of cloud microphysics parameterization in CRMs. Two papers of Powell et al (2012) and Zeng et al. (2013), summarizing these studies, were published in the Journal of the Atmospheric Sciences. 4. Analyzed the water budgets of MCSs Using ARM data from TWP-ICE, ARM-SGP and other field campaigns, the Goddard CRM simulations were carried out to analyze the water budgets of clouds from TWP-ICE and AMMA. The simulations generated a set of datasets on clouds and radiation, which are available http://cloud.gsfc.nasa.gov/. The cloud datasets were available for modelers and other researchers aiming to improve the representation of cloud processes in multi-scale modeling frameworks, GCMs and climate models. Special datasets, such as 3D cloud distributions every six minutes for TWP-ICE, were requested and generated for ARM/ASR investigators. Data server records show that 86,206 datasets were downloaded by 120 users between April of 2010 and January of 2012. 5. MMF simulations The Goddard MMF (multi-scale modeling framework) has been improved by coupling with the Goddard Land Information System (LIS) and the Goddard Earth Observing System Model, Version 5 (GOES5). It has also been optimized on NASA HEC supercomputers and can be run over 4000 CPUs. The improved MMF with high horizontal resolution (1 x 1 degree) is currently being applied to cases covering 2005 and 2006. The results show that the spatial distribution pattern of precipitation rate is well simulated by the MMF through comparisons with satellite retrievals from the CMOPRH and GPCP data sets. In addition, the MMF results were compared with three reanalyses (MERRA, ERA-Interim and CFSR). Although the MMF tends to produce a higher precipitation rate over some topical regions, it actually well captures the variations in the zonal and meridional means. Among the three reanalyses, ERA-Interim seems to have values close to those of the satellite retrievals especially for GPCP. It is interesting to note that the MMF obtained the best results in the rain forest of Africa even better than those of CFSR and ERA-Interim, when compared to CMORPH. MERRA fails to capture the precipitation in this region. We are now collaborating with Steve Rutledge (CSU) to validate the model results for AMMA 6. MC3E and the diurnal variation of precipitation processes The Midlatitude Continental Convective Clouds Experiment (MC3E) was a joint field campaign between the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility and the NASA Global Precipitation Measurement (GPM) mission Ground Validation (GV) program. It took place in central Oklahoma during the period April 22 _ June 6, 2011. Some of its major objectives involve the use of CRMs in precipitation science such as: (1) testing the fidelity of CRM simulations via intensive statistical comparisons between simulated and observed cloud properties and latent heating fields for a variety of case types, (2) establishing the limits of CRM space-time integration capabilities for quantitative precipitation estimates, and (3) supporting the development and refinement of physically-based GMI, DPR, and DPR-GMI combined retrieval algorithms using ground-based GPM GV Ku-Ka band radar and CRM simulations. The NASA unified WRF model (nu-WRF) was used for real time forecasts during the field campaign, and ten precipitation events were selected for post mission simulations. These events include well-organized squall lines, scattered storms and quasi-linear storms. A paper focused on the diurnal variation of precipitation will be submitted in September 2012. The major highlights are as follows: a. The results indicate that NU-WRF model could capture observed diurnal variation of rainfall (composite not individual); b. NU-WRF model could simulate two different types (propagating and local type) of the diurnal variation of rainfall; c. NU-WRF model simulation show very good agreement with observation in terms of precipitation pattern (linear MCS), radar reflectivity (a second low peak shallow convection); d. NU-WRF model simulation indicates that the cool-pool dynamic is the main physical process for MCS propagation speed; e. Surface heat fluxes (including land surface model and initial surface condition) do not play a major role in phase of diurnal variation (change rainfall amount slightly); f. Terrain effect is important for initial stage of MCS (rainfall is increased and close to observation by increasing the terrain height that is also close to observed); g. Diurnal variation of radiation is not important for the simulated variation of rainfall. Publications: Zeng, X., W.-K. Tao, S. Powell, R. Houze, Jr., P. Ciesielski, N. Guy, H. Pierce and T. Matsui, 2012: A comparison of the water budgets between clouds from AMMA and TWP-ICE. J. Atmos. Sci., 70, 487-503. Powell, S. W., R. A. Houze, Jr., A. Kumar, and S. A. McFarlane, 2012: Comparison of simulated and observed continental tropical anvil clouds and their radiative heating profiles. J. Atmos. Sci., 69, 2662-2681. Zeng, X., W.-K. Tao, T. Matsui, S. Xie, S. Lang, M. Zhang, D. Starr, and X. Li, 2011: Estimating the Ice Crystal Enhancement Factor in the Tropics. J. Atmos. Sci., 68, 1424-1434. Conferences: Zeng, X., W.-K. Tao, S. Powell, R. Houze, Jr., P. Ciesielski, N. Guy, H. Pierce and T. Matsui, 2012: Comparison of water budget between AMMA and TWP-ICE clouds. The 3rd Annual ASR Science Team Meeting. Arlington, Virginia, Mar. 12-16, 2012. Zeng, X., W.-K. Tao, S. Powell, R. A. Houze Jr., and P. Ciesielski, 2011: Comparing the water budgets between AMMA and TWP-ICE clouds. Fall 2011 ASR Working Group Meeting. Annapolis, September 12-16, 2011. Zeng, X. et al., 2011: Introducing ice nuclei into turbulence parameterizations in CRMs. Fall 2011 ASR Working Group Meeting. Annapolis, September 12-16, 2011.« less

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

Jensen, Michael P.; Holdridge, Donna J.; Survo, Petteri

In the fall of 2013, the Vaisala RS41 (fourth generation) radiosonde was introduced as a replacement for the RS92-SGP radiosonde with improvements in measurement accuracy of profiles of atmospheric temperature, humidity, and pressure. In order to help characterize these improvements, an intercomparison campaign was undertaken at the US Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facility site in north-central Oklahoma, USA. During 3–8 June 2014, a total of 20 twin-radiosonde flights were performed in a variety of atmospheric conditions representing typical midlatitude continental summertime conditions. The results show that for most of the observed conditions the RS92 andmore » RS41 measurements agree much better than the manufacturer-specified combined uncertainties with notable exceptions when exiting liquid cloud layers where the “wet-bulbing” effect appears to be mitigated for several cases in the RS41 observations. The RS41 measurements of temperature and humidity, with applied correction algorithms, also appear to show less sensitivity to solar heating. In addition, these results suggest that the RS41 does provide important improvements, particularly in cloudy conditions. For many science applications – such as atmospheric process studies, retrieval development, and weather forecasting and climate modeling – the differences between the RS92 and RS41 measurements should have little impact. However, for long-term trend analysis and other climate applications, additional characterization of the RS41 measurements and their relation to the long-term observational records will be required.« less

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

Jensen, Michael P.; Holdridge, Donna J.; Survo, Petteri

In the fall of 2013, the Vaisala RS41 (fourth generation) radiosonde was introduced as a replacement for the RS92-SGP radiosonde with improvements in measurement accuracy of profiles of atmospheric temperature, humidity, and pressure. In order to help characterize these improvements, an intercomparison campaign was undertaken at the US Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facility site in north-central Oklahoma, USA. During 3–8 June 2014, a total of 20 twin-radiosonde flights were performed in a variety of atmospheric conditions representing typical midlatitude continental summertime conditions. The results show that for most of the observed conditions the RS92 andmore » RS41 measurements agree much better than the manufacturer-specified combined uncertainties with notable exceptions when exiting liquid cloud layers where the “wet-bulbing” effect appears to be mitigated for several cases in the RS41 observations. The RS41 measurements of temperature and humidity, with applied correction algorithms, also appear to show less sensitivity to solar heating. These results suggest that the RS41 does provide important improvements, particularly in cloudy conditions. For many science applications – such as atmospheric process studies, retrieval development, and weather forecasting and climate modeling – the differences between the RS92 and RS41 measurements should have little impact. However, for long-term trend analysis and other climate applications, additional characterization of the RS41 measurements and their relation to the long-term observational records will be required.« less

Identification and Expression of Acetylcholinesterase in Octopus vulgaris Arm Development and Regeneration: a Conserved Role for ACHE?

PubMed

Fossati, Sara Maria; Candiani, Simona; Nödl, Marie-Therese; Maragliano, Luca; Pennuto, Maria; Domingues, Pedro; Benfenati, Fabio; Pestarino, Mario; Zullo, Letizia

2015-08-01

Acetylcholinesterase (ACHE) is a glycoprotein with a key role in terminating synaptic transmission in cholinergic neurons of both vertebrates and invertebrates. ACHE is also involved in the regulation of cell growth and morphogenesis during embryogenesis and regeneration acting through its non-cholinergic sites. The mollusk Octopus vulgaris provides a powerful model for investigating the mechanisms underlying tissue morphogenesis due to its high regenerative power. Here, we performed a comparative investigation of arm morphogenesis during adult arm regeneration and embryonic arm development which may provide insights on the conserved ACHE pathways. In this study, we cloned and characterized O. vulgaris ACHE, finding a single highly conserved ACHE hydrophobic variant, characterized by prototypical catalytic sites and a putative consensus region for a glycosylphosphatidylinositol (GPI)-anchor attachment at the COOH-terminus. We then show that its expression level is correlated to the stage of morphogenesis in both adult and embryonic arm. In particular, ACHE is localized in typical neuronal sites when adult-like arm morphology is established and in differentiating cell locations during the early stages of arm morphogenesis. This possibility is also supported by the presence in the ACHE sequence and model structure of both cholinergic and non-cholinergic sites. This study provides insights into ACHE conserved roles during processes of arm morphogenesis. In addition, our modeling study offers a solid basis for predicting the interaction of the ACHE domains with pharmacological blockers for in vivo investigations. We therefore suggest ACHE as a target for the regulation of tissue morphogenesis.

East Asian Studies of Tropospheric Aerosols and their Impact on Regional Climate (EAST-AIRC): An Overview

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

Li, Zhanqing; Li, C.; Chen, H.

2011-02-01

As the most populated region of the world, Asia is a major source of aerosols with potential large impact over vast downstream areas. Papers published in this special section describe the variety of aerosols observed in China and their effects and interactions with the regional climate as part of the East Asian Study of Tropospheric Aerosols and Impact on Regional Climate (EAST-AIRC). The majority of the papers are based on analyses of observations made under three field projects, namely, the Atmospheric Radiation Measurements (ARM) Mobile Facility mission in China (AMF10 China), the East Asian Study of Tropospheric Aerosols: an Internationalmore » Regional Experiment (EAST-AIRE), and the Atmospheric Aerosols of China and their Climate Effects (AACCE). The former two are US-China collaborative projects and the latter is a part of the China’s National Basic Research program (or often referred to as “973 project”). Routine meteorological data of China are also employed in some studies. The wealth of general and specialized measurements lead to extensive and close-up investigations of the optical, physical and chemical properties of anthropogenic, natural, and mixed aerosols; their sources, formation and transport mechanisms; horizontal, vertical and temporal variations; direct and indirect effects and interactions with the East Asian monsoon system. Particular efforts are made to advance our understanding of the mixing and interaction between dust and anthropogenic pollutants during transport. Several modeling studies were carried out to simulate aerosol impact on radiation budget, temperature, precipitation, wind and atmospheric circulation, fog, etc. In addition, impacts of the Asian monsoon system on aerosol loading are also simulated.« less

Formalization of the Access Control on ARM-Android Platform with the B Method

NASA Astrophysics Data System (ADS)

Ren, Lu; Wang, Wei; Zhu, Xiaodong; Man, Yujia; Yin, Qing

2018-01-01

ARM-Android is a widespread mobile platform with multi-layer access control mechanisms, security-critical in the system. Many access control vulnerabilities still exist due to the course-grained policy and numerous engineering defects, which have been widely studied. However, few researches focus on the mechanism formalization, including the Android permission framework, kernel process management and hardware isolation. This paper first develops a comprehensive formal access control model on the ARM-Android platform using the B method, from the Android middleware to hardware layer. All the model specifications are type checked and proved to be well-defined, with 75%of proof obligations demonstrated automatically. The results show that the proposed B model is feasible to specify and verify access control schemes in the ARM-Android system, and capable of implementing a practical control module.

Perceptions of Hazing and Bullying among U.S. Military Service Members

DTIC Science & Technology

2016-10-18

Institute (DEOMI) Organizational Climate Survey (DEOCS), perceptions of hazing and bullying among SMs of all branches of the U.S. Armed Forces (except...recorded survey responses. Reserve, Guard, Civilian, and Coast Guard respondents were excluded from the sample, thus resulting in 620,629 Active Duty...of respondents, some units may take the survey multiple times within a year due to commander turnover, mandatory regulatory requirements, or permanent

The Army Study Program Fiscal Year 1984 Report. Volume 2.

DTIC Science & Technology

1984-01-01

TRADOC COMBINED ARMS I& A NUCLEAR ENVIRONMENT (CAKE) FDTE ATORT-D-001 TRADOC COMMAND CLIMATE ASSESSMENT DAPEH-E-042 DCSPER COMMUNICATIONS VISSION AREA ...ANALYSIS 2538 TRADOC COMMUNICATIONS MISSION AREA ANALYSIS. LEVEL II. ATZHC-E-002 TRADOC COMMUNICATIONS SUPPORT REQUIREMENTS ATZLC-E-002 TRADOC COMC...CORPS (EAC) AWCIS-D-002 SSI ECHELONS AFCVE CCRFS COMMUNICATIONS PISSION AREA ANALYSIS (EUROPE) CCOPS-D-002 USACC ECONOMIC IMPACT GENERATED AGAINST

Bulgaria in European Security and Defense Policy

DTIC Science & Technology

2013-03-01

simple message that, countries like Israel the U.S. and others are the "eternal enemy". Despite arms control and efforts to counter the proliferation...or alter its distribution; this will reduce the fish food source and trigger migration from mid- latitudes in the northern waters. Forests provide...have long-term effects on climate, soil, and their storage.4 Global food production, including genetically modified food, will continue to grow

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

Zhang, Damao; Wang, Zhien; Heymsfield, Andrew J.

Measurement of ice number concentration in clouds is important but still challenging. Stratiform mixed-phase clouds (SMCs) provide a simple scenario for retrieving ice number concentration from remote sensing measurements. The simple ice generation and growth pattern in SMCs offers opportunities to use cloud radar reflectivity (Ze) measurements and other cloud properties to infer ice number concentration quantitatively. To understand the strong temperature dependency of ice habit and growth rate quantitatively, we develop a 1-D ice growth model to calculate the ice diffusional growth along its falling trajectory in SMCs. The radar reflectivity and fall velocity profiles of ice crystals calculatedmore » from the 1-D ice growth model are evaluated with the Atmospheric Radiation Measurements (ARM) Climate Research Facility (ACRF) ground-based high vertical resolution radar measurements. Combining Ze measurements and 1-D ice growth model simulations, we develop a method to retrieve the ice number concentrations in SMCs at given cloud top temperature (CTT) and liquid water path (LWP). The retrieved ice concentrations in SMCs are evaluated with in situ measurements and with a three-dimensional cloud-resolving model simulation with a bin microphysical scheme. These comparisons show that the retrieved ice number concentrations are within an uncertainty of a factor of 2, statistically.« less

Early detection versus primary prevention in the PLCO flexible sigmoidoscopy screening trial: Which has the greatest impact on mortality?

PubMed

Doroudi, Maryam; Schoen, Robert E; Pinsky, Paul F

2017-12-15

Screening for colorectal cancer (CRC) with flexible sigmoidoscopy (FS) has been shown to reduce CRC mortality. The current study examined whether the observed mortality reduction was due primarily to the prevention of incident CRC via removal of adenomatous polyps or to the early detection of cancer and improved survival. The Prostate, Lung, Colorectal, and Ovarian (PLCO) cancer screening trial randomized 154,900 men and women aged 55 to 74 years. Individuals underwent FS screening at baseline and at 3 or 5 years versus usual care. CRC-specific survival was analyzed using Kaplan-Meier curves and proportional hazards modeling. The authors estimated the percentage of CRC deaths averted by early detection versus primary prevention using a model that applied intervention arm survival rates to CRC cases in the usual-care arm and vice versa. A total of 1008 cases of CRC in the intervention arm and 1291 cases of CRC in the usual-care arm were observed. Through 13 years of follow-up, there was no significant difference noted between the trial arms with regard to CRC-specific survival for all CRC (68% in the intervention arm vs 65% in the usual-care arm; P =.16) or proximal CRC (68% vs 62%, respectively; P = .11) cases; however, survival in distal CRC cases was found to be higher in the intervention arm compared with the usual-care arm (77% vs 66%; P<.0001). Within each arm, symptom-detected cases had significantly worse survival compared with screen-detected cases. Overall, approximately 29% to 35% of averted CRC deaths were estimated to be due to early detection and 65% to 71% were estimated to be due to primary prevention. CRC-specific survival was similar across arms in the PLCO trial, suggesting a limited role for early detection in preventing CRC deaths. Modeling suggested that approximately two-thirds of avoided deaths were due to primary prevention. Future CRC screening guidelines should emphasize primary prevention via the identification and removal of precursor lesions. Cancer 2017;123:4815-22. © 2017 American Cancer Society. © 2017 American Cancer Society.

Shaping of arm configuration space by prescription of non-Euclidean metrics with applications to human motor control

NASA Astrophysics Data System (ADS)

Biess, Armin

2013-01-01

The study of the kinematic and dynamic features of human arm movements provides insights into the computational strategies underlying human motor control. In this paper a differential geometric approach to movement control is taken by endowing arm configuration space with different non-Euclidean metric structures to study the predictions of the generalized minimum-jerk (MJ) model in the resulting Riemannian manifold for different types of human arm movements. For each metric space the solution of the generalized MJ model is given by reparametrized geodesic paths. This geodesic model is applied to a variety of motor tasks ranging from three-dimensional unconstrained movements of a four degree of freedom arm between pointlike targets to constrained movements where the hand location is confined to a surface (e.g., a sphere) or a curve (e.g., an ellipse). For the latter speed-curvature relations are derived depending on the boundary conditions imposed (periodic or nonperiodic) and the compatibility with the empirical one-third power law is shown. Based on these theoretical studies and recent experimental findings, I argue that geodesics may be an emergent property of the motor system and that the sensorimotor system may shape arm configuration space by learning metric structures through sensorimotor feedback.

Modelling of loading, stress relaxation and stress recovery in a shape memory polymer.

PubMed

Sweeney, J; Bonner, M; Ward, I M

2014-09-01

A multi-element constitutive model for a lactide-based shape memory polymer has been developed that represents loading to large tensile deformations, stress relaxation and stress recovery at 60, 65 and 70°C. The model consists of parallel Maxwell arms each comprising neo-Hookean and Eyring elements. Guiu-Pratt analysis of the stress relaxation curves yields Eyring parameters. When these parameters are used to define the Eyring process in a single Maxwell arm, the resulting model yields at too low a stress, but gives good predictions for longer times. Stress dip tests show a very stiff response on unloading by a small strain decrement. This would create an unrealistically high stress on loading to large strain if it were modelled by an elastic element. Instead it is modelled by an Eyring process operating via a flow rule that introduces strain hardening after yield. When this process is incorporated into a second parallel Maxwell arm, there results a model that fully represents both stress relaxation and stress dip tests at 60°C. At higher temperatures a third arm is required for valid predictions. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

Psychosis prediction in secondary mental health services. A broad, comprehensive approach to the "at risk mental state" syndrome.

PubMed

Francesconi, M; Minichino, A; Carrión, R E; Delle Chiaie, R; Bevilacqua, A; Parisi, M; Rullo, S; Bersani, F Saverio; Biondi, M; Cadenhead, K

2017-02-01

Accuracy of risk algorithms for psychosis prediction in "at risk mental state" (ARMS) samples may differ according to the recruitment setting. Standardized criteria used to detect ARMS individuals may lack specificity if the recruitment setting is a secondary mental health service. The authors tested a modified strategy to predict psychosis conversion in this setting by using a systematic selection of trait-markers of the psychosis prodrome in a sample with a heterogeneous ARMS status. 138 non-psychotic outpatients (aged 17-31) were consecutively recruited in secondary mental health services and followed-up for up to 3 years (mean follow-up time, 2.2 years; SD=0.9). Baseline ARMS status, clinical, demographic, cognitive, and neurological soft signs measures were collected. Cox regression was used to derive a risk index. 48% individuals met ARMS criteria (ARMS-Positive, ARMS+). Conversion rate to psychosis was 21% for the overall sample, 34% for ARMS+, and 9% for ARMS-Negative (ARMS-). The final predictor model with a positive predictive validity of 80% consisted of four variables: Disorder of Thought Content, visuospatial/constructional deficits, sensory-integration, and theory-of-mind abnormalities. Removing Disorder of Thought Content from the model only slightly modified the predictive accuracy (-6.2%), but increased the sensitivity (+9.5%). These results suggest that in a secondary mental health setting the use of trait-markers of the psychosis prodrome may predict psychosis conversion with great accuracy despite the heterogeneity of the ARMS status. The use of the proposed predictive algorithm may enable a selective recruitment, potentially reducing duration of untreated psychosis and improving prognostic outcomes. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Action sounds update the mental representation of arm dimension: contributions of kinaesthesia and agency

PubMed Central

Tajadura-Jiménez, Ana; Tsakiris, Manos; Marquardt, Torsten; Bianchi-Berthouze, Nadia

2015-01-01

Auditory feedback accompanies almost all our actions, but its contribution to body-representation is understudied. Recently it has been shown that the auditory distance of action sounds recalibrates perceived tactile distances on one’s arm, suggesting that action sounds can change the mental representation of arm length. However, the question remains open of what factors play a role in this recalibration. In this study we investigate two of these factors, kinaesthesia, and sense of agency. Across two experiments, we asked participants to tap with their arm on a surface while extending their arm. We manipulated the tapping sounds to originate at double the distance to the tapping locations, as well as their synchrony to the action, which is known to affect feelings of agency over the sounds. Kinaesthetic cues were manipulated by having additional conditions in which participants did not displace their arm but kept tapping either close (Experiment 1) or far (Experiment 2) from their body torso. Results show that both the feelings of agency over the action sounds and kinaesthetic cues signaling arm displacement when displacement of the sound source occurs are necessary to observe changes in perceived tactile distance on the arm. In particular, these cues resulted in the perceived tactile distances on the arm being felt smaller, as compared to distances on a reference location. Moreover, our results provide the first evidence of consciously perceived changes in arm-representation evoked by action sounds and suggest that the observed changes in perceived tactile distance relate to experienced arm elongation. We discuss the observed effects in the context of forward internal models of sensorimotor integration. Our results add to these models by showing that predictions related to action sounds must fit with kinaesthetic cues in order for auditory inputs to change body-representation. PMID:26074843

Bioinspired locomotion and grasping in water: the soft eight-arm OCTOPUS robot.

PubMed

Cianchetti, M; Calisti, M; Margheri, L; Kuba, M; Laschi, C

2015-05-13

The octopus is an interesting model for the development of soft robotics, due to its high deformability, dexterity and rich behavioural repertoire. To investigate the principles of octopus dexterity, we designed an eight-arm soft robot and evaluated its performance with focused experiments. The OCTOPUS robot presented here is a completely soft robot, which integrates eight arms extending in radial direction and a central body which contains the main processing units. The front arms are mainly used for elongation and grasping, while the others are mainly used for locomotion. The robotic octopus works in water and its buoyancy is close to neutral. The experimental results show that the octopus-inspired robot can walk in water using the same strategy as the animal model, with good performance over different surfaces, including walking through physical constraints. It can grasp objects of different sizes and shapes, thanks to its soft arm materials and conical shape.

An Air Revitalization Model (ARM) for Regenerative Life Support Systems (RLSS)

NASA Technical Reports Server (NTRS)

Hart, Maxwell M.

1990-01-01

The primary objective of the air revitalization model (ARM) is to determine the minimum buffer capacities that would be necessary for long duration space missions. Several observations are supported by the current configuration sizes: the baseline values for each gas and the day to day or month to month fluctuations that are allowed. The baseline values depend on the minimum safety tolerances and the quantities of life support consumables necessary to survive the worst case scenarios within those tolerances. Most, it not all, of these quantities can easily be determined by ARM once these tolerances are set. The day to day fluctuations also require a command decision. It is already apparent from the current configuration of ARM that the tighter these fluctuations are controlled, the more energy used, the more nonregenerable hydrazine consumed, and the larger the required capacities for the various gas generators. All of these relationships could clearly be quantified by one operational ARM.

New nonlinear control algorithms for multiple robot arms

NASA Technical Reports Server (NTRS)

Tarn, T. J.; Bejczy, A. K.; Yun, X.

1988-01-01

Multiple coordinated robot arms are modeled by considering the arms as closed kinematic chains and as a force-constrained mechanical system working on the same object simultaneously. In both formulations, a novel dynamic control method is discussed. It is based on feedback linearization and simultaneous output decoupling technique. By applying a nonlinear feedback and a nonlinear coordinate transformation, the complicated model of the multiple robot arms in either formulation is converted into a linear and output decoupled system. The linear system control theory and optimal control theory are used to design robust controllers in the task space. The first formulation has the advantage of automatically handling the coordination and load distribution among the robot arms. In the second formulation, it was found that by choosing a general output equation it became possible simultaneously to superimpose the position and velocity error feedback with the force-torque error feedback in the task space.

Interaction of multiarmed spirals in bistable media.

PubMed

He, Ya-feng; Ai, Bao-quan; Liu, Fu-cheng

2013-05-01

We study the interaction of both dense and sparse multiarmed spirals in bistable media modeled by equations of the FitzHugh-Nagumo type. A dense one-armed spiral is characterized by its fixed tip. For dense multiarmed spirals, when the initial distance between tips is less than a critical value, the arms collide, connect, and disconnect continuously as the spirals rotate. The continuous reconstruction between the front and the back drives the tips to corotate along a rough circle and to meander zigzaggedly. The rotation frequency of tip, the frequency of zigzagged displacement, the frequency of spiral, the oscillation frequency of media, and the number of arms satisfy certain relations as long as the control parameters of the model are fixed. When the initial distance between tips is larger than the critical value, the behaviors of individual arms within either dense or sparse multiarmed spirals are identical to that of corresponding one-armed spirals.

Differential Equation Models for Sharp Threshold Dynamics

DTIC Science & Technology

2012-08-01

dynamics, and the Lanchester model of armed conflict, where the loss of a key capability drastically changes dynamics. We derive and demonstrate a step...dynamics using differential equations. 15. SUBJECT TERMS Differential Equations, Markov Population Process, S-I-R Epidemic, Lanchester Model 16...infection, where a detection event drastically changes dynamics, and the Lanchester model of armed conflict, where the loss of a key capability

Finite Element Model to Reduce Fire and Blast Vulnerability

DTIC Science & Technology

2013-01-01

4 Figure 4. Scapula, Clavicle and Arm Models Attached to the Larger Model .............................. 5 Figure 5. The Full Body...Finite Element Model of the Lower Limbs UNCLASSIFIED 4 UNCLASSIFIED Anatomical surfaces of the scapula and clavicle were obtained and...ulna and hand bones. For the arms, hands, scapula and clavicle , the materials were made to be rigid and joints created using computational constraints

Multi-decadal analysis of root-zone soil moisture applying the exponential filter across CONUS

NASA Astrophysics Data System (ADS)

Tobin, Kenneth J.; Torres, Roberto; Crow, Wade T.; Bennett, Marvin E.

2017-09-01

This study applied the exponential filter to produce an estimate of root-zone soil moisture (RZSM). Four types of microwave-based, surface satellite soil moisture were used. The core remotely sensed data for this study came from NASA's long-lasting AMSR-E mission. Additionally, three other products were obtained from the European Space Agency Climate Change Initiative (CCI). These datasets were blended based on all available satellite observations (CCI-active, CCI-passive, and CCI-combined). All of these products were 0.25° and taken daily. We applied the filter to produce a soil moisture index (SWI) that others have successfully used to estimate RZSM. The only unknown in this approach was the characteristic time of soil moisture variation (T). We examined five different eras (1997-2002; 2002-2005; 2005-2008; 2008-2011; 2011-2014) that represented periods with different satellite data sensors. SWI values were compared with in situ soil moisture data from the International Soil Moisture Network at a depth ranging from 20 to 25 cm. Selected networks included the US Department of Energy Atmospheric Radiation Measurement (ARM) program (25 cm), Soil Climate Analysis Network (SCAN; 20.32 cm), SNOwpack TELemetry (SNOTEL; 20.32 cm), and the US Climate Reference Network (USCRN; 20 cm). We selected in situ stations that had reasonable completeness. These datasets were used to filter out periods with freezing temperatures and rainfall using data from the Parameter elevation Regression on Independent Slopes Model (PRISM). Additionally, we only examined sites where surface and root-zone soil moisture had a reasonably high lagged r value (r > 0. 5). The unknown T value was constrained based on two approaches: optimization of root mean square error (RMSE) and calculation based on the normalized difference vegetation index (NDVI) value. Both approaches yielded comparable results; although, as to be expected, the optimization approach generally outperformed NDVI-based estimates. The best results were noted at stations that had an absolute bias within 10 %. SWI estimates were more impacted by the in situ network than the surface satellite product used to drive the exponential filter. The average Nash-Sutcliffe coefficients (NSs) for ARM ranged from -0. 1 to 0.3 and were similar to the results obtained from the USCRN network (0.2-0.3). NS values from the SCAN and SNOTEL networks were slightly higher (0.1-0.5). These results indicated that this approach had some skill in providing an estimate of RZSM. In terms of RMSE (in volumetric soil moisture), ARM values actually outperformed those from other networks (0.02-0.04). SCAN and USCRN RMSE average values ranged from 0.04 to 0.06 and SNOTEL average RMSE values were higher (0.05-0.07). These values were close to 0.04, which is the baseline value for accuracy designated for many satellite soil moisture missions.

Morphology-flow interactions lead to stage-selective vertical transport of larval sand dollars in shear flow.

PubMed

Clay, T W; Grünbaum, D

2010-04-01

Many larvae and other plankton have complex and variable morphologies of unknown functional significance. We experimentally and theoretically investigated the functional consequences of the complex morphologies of larval sand dollars, Dendraster excentricus (Eschscholtz), for hydrodynamic interactions between swimming and turbulent water motion. Vertical shearing flows (horizontal gradients of vertical flow) tilt organisms with simple geometries (e.g. spheres, ellipsoids), causing these organisms to move horizontally towards downwelling water and compromising their abilities to swim upwards. A biomechanical model of corresponding hydrodynamic interactions between turbulence-induced shear and the morphologically complex four-, six- and eight-armed stages of sand dollar larvae suggests that the movements of larval morphologies differ quantitatively and qualitatively across stages and shear intensities: at shear levels typical of calm conditions in estuarine and coastal environments, all modeled larval stages moved upward. However, at higher shears, modeled four- and eight-armed larvae moved towards downwelling, whereas six-armed larvae moved towards upwelling. We also experimentally quantified larval movement by tracking larvae swimming in low-intensity shear while simultaneously mapping the surrounding flow fields. Four- and eight-armed larvae moved into downwelling water, but six-armed larvae did not. Both the model and experiments suggest that stage-dependent changes to larval morphology lead to differences in larval movement: four- and eight-armed stages are more prone than the six-armed stage to moving into downwelling water. Our results suggest a mechanism by which differences can arise in the vertical distribution among larval stages. The ability to mitigate or exploit hydrodynamic interactions with shear is a functional consequence that potentially shapes larval evolution and development.

Do dominant and non-dominant arms respond similarly to maximal eccentric exercise of the elbow flexors?

PubMed

Newton, Michael J; Sacco, Paul; Chapman, Dale; Nosaka, Kazunori

2013-03-01

Two common models to investigate the effect of interventions on muscle damage include using two groups in which one group receives an intervention while the other acts as control, and using contralateral limbs of one group. The latter model is based on the assumption that changes in markers of muscle damage are similar between limbs, but this has not been examined systematically. This study compared changes in muscle damage markers between dominant and non-dominant arms following maximal eccentric exercise of the elbow flexors. Eighteen men performed 60 maximal eccentric elbow flexions of each arm separated by 4 weeks with the order of testing between arms randomised. Maximal voluntary isometric torque, range of motion, upper arm circumference, plasma creatine kinase (CK) activity and muscle soreness before and for 7 days following exercise were compared between arms using two-way repeated measures ANOVA. No significant differences between arms were evident for any of the markers, but significant (P<0.05) differences between first and second bouts were evident for changes in strength, circumference and CK with smaller changes following the second bout. A poor correlation was found for the magnitude of changes in the markers between dominant and non-dominant arms, suggesting that responses to eccentric exercise were not necessarily the same between arms. These results show that the order affected the responses of dominant and non-dominant arms to the eccentric exercise; however, the contralateral limb design appears to be usable if bout order is counterbalanced and randomised among participants. Copyright © 2012. Published by Elsevier Ltd.

Spiral structure of M51: Streaming motions across the spiral arms

NASA Technical Reports Server (NTRS)

Tilanus, R. P. J.; Allen, R. J.

1990-01-01

The atomic hydrogen (HI) and the H alpha emission line in the grand-design spiral galaxy M51 have been observed with the Westerbork Synthesis Radio Telescope and the Taurus Fabry-Perot imaging spectrometer, respectively. Across the inner spiral arms significant tangential and radial velocity gradients are detected in the H alpha emission after subtraction of the axi-symmetric component of the velocity field. The shift is positive on the inside and negative on the outside of the northern arm. Across the southern arm this situation is reversed. The direction of the shifts is such that the material is moving inward and faster compared to circular rotation in both arms, consistent with the velocity perturbations predicted by spiral density wave models for gas downstream of a spiral shock. The observed shifts amount to 20 to 30 km (s-1), corresponding to streaming motions of 60 to 90 km (s-1) in the plane of the disk (inclination angle 20 degrees). Comparable velocity gradients have also been observed by Vogel et al. in the CO emission from the inner northern arm of M51. The streaming motions in M51 are about 2 to 3 times as large as the ones found in HI by Rots in M81, and successfully modelled by Visser with a self-consistent density wave model. Researchers have not been able to detect conclusively streaming motions in the HI emission from the arms, perhaps due to the relatively poor angular resolution (approx. 15 seconds) of the HI observations.

Psychosocial effects of workplace physical exercise among workers with chronic pain

PubMed Central

Andersen, Lars L.; Persson, Roger; Jakobsen, Markus D.; Sundstrup, Emil

2017-01-01

Abstract While workplace physical exercise can help manage musculoskeletal disorders, less is known about psychosocial effects of such interventions. This aim of this study was to investigate the effect of workplace physical exercise on psychosocial factors among workers with chronic musculoskeletal pain. The trial design was a 2-armed parallel-group randomized controlled trial with allocation concealment. A total of 66 slaughterhouse workers (51 men and 15 women, mean age 45 years [standard deviation (SD) 10]) with upper limb chronic musculoskeletal pain were randomly allocated to group-based strength training (physical exercise group) or individual ergonomic training and education (reference group) for 10 weeks. Social climate was assessed with the General Nordic Questionnaire for Psychological and Social Factors at Work, and vitality and mental health were assessed with the 36-item Short Form Health Survey. All scales were converted to 0 to 100 (higher scores are better). Between-group differences from baseline to follow-up were determined using linear mixed models adjusted for workplace, age, gender, and baseline values of the outcome. Mean baseline scores of social climate, mental health, and vitality were 52.2 (SD 14.9), 79.5 (SD 13.7), and 53.9 (SD 19.7), respectively. Complete baseline and follow-up data were obtained from 30 and 31 from the physical exercise and reference groups, respectively. The between-group differences from baseline to follow-up between physical exercise and reference were 7.6 (95% CI 0.3 to 14.9), −2.3 (95% CI -10.3 to 5.8), and 10.1 (95% CI 0.6 to 19.5) for social climate, mental health, and vitality, respectively. For social climate and vitality, this corresponded to moderate effect sizes (Cohen d = 0.51 for both) in favor of physical exercise. There were no reported adverse events. In conclusion, workplace physical exercise performed together with colleagues improves social climate and vitality among workers with chronic musculoskeletal pain. Mental health remained unchanged. PMID:28072707

Currents of Change

NASA Astrophysics Data System (ADS)

Glantz, Michael H.

2000-12-01

Headlines around the world about severe droughts, hurricanes, and floods caused by El Niño and La Niña appear every few years. El Niño is the second most important climate process after the changing seasons; its effects are widely known, but the equally serious impact of La Niña is only now beginning to be appreciated. Fully revised, Currents of Change clearly explains what El Niño and La Niña are and how they can be forecast. Examining for the first time the major El Niño of 1997-1998, Michael Glantz explains what we can learn from past events, how we can better manage climate-sensitive activities, and how to anticipate what future storms and droughts may occur. A century ago, it was of interest only to Peruvian fishermen and farmers. Today, scientists armed with tremendous computer models and satellites realize that El Niño and La Niña affect climatic conditions in seemingly remote parts of the world and are better able to predict which regions will be affected. Including the latest information about El Niño and La Niña, this new edition of Currents of Change will be useful to scientists, policymakers, economists, and interested readers alike. Michael Glantz is a Senior Scientist with the US National Center for Atmospheric Research (NCAR) in the Environmental and Societal Impacts Group, a program of NCAR. He is the coordinator of a 16-country El Niño impacts and response strategies study for the United Nations. Glantz is a member of numerous national and international committees and advisory bodies and is a recipient of the 1987 World Hunger Media Award, of UNEP's Global 500 Award, and the 1991 Mitchell Prize for Sustainable Development. He is the author of Climate Variability, Climate Change, and Fisheries (Cambridge, 1992) and Drought Follows the Plow (Cambridge, 1994). He lives in Boulder, Colorado.

Psychosocial effects of workplace physical exercise among workers with chronic pain: Randomized controlled trial.

PubMed

Andersen, Lars L; Persson, Roger; Jakobsen, Markus D; Sundstrup, Emil

2017-01-01

While workplace physical exercise can help manage musculoskeletal disorders, less is known about psychosocial effects of such interventions. This aim of this study was to investigate the effect of workplace physical exercise on psychosocial factors among workers with chronic musculoskeletal pain.The trial design was a 2-armed parallel-group randomized controlled trial with allocation concealment. A total of 66 slaughterhouse workers (51 men and 15 women, mean age 45 years [standard deviation (SD) 10]) with upper limb chronic musculoskeletal pain were randomly allocated to group-based strength training (physical exercise group) or individual ergonomic training and education (reference group) for 10 weeks. Social climate was assessed with the General Nordic Questionnaire for Psychological and Social Factors at Work, and vitality and mental health were assessed with the 36-item Short Form Health Survey. All scales were converted to 0 to 100 (higher scores are better). Between-group differences from baseline to follow-up were determined using linear mixed models adjusted for workplace, age, gender, and baseline values of the outcome.Mean baseline scores of social climate, mental health, and vitality were 52.2 (SD 14.9), 79.5 (SD 13.7), and 53.9 (SD 19.7), respectively. Complete baseline and follow-up data were obtained from 30 and 31 from the physical exercise and reference groups, respectively. The between-group differences from baseline to follow-up between physical exercise and reference were 7.6 (95% CI 0.3 to 14.9), -2.3 (95% CI -10.3 to 5.8), and 10.1 (95% CI 0.6 to 19.5) for social climate, mental health, and vitality, respectively. For social climate and vitality, this corresponded to moderate effect sizes (Cohen d = 0.51 for both) in favor of physical exercise. There were no reported adverse events.In conclusion, workplace physical exercise performed together with colleagues improves social climate and vitality among workers with chronic musculoskeletal pain. Mental health remained unchanged.

Science Overview Document Indirect and Semi-Direct Aerosol Campaign (ISDAC) April 2008

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

SJ Ghan; B Schmid; JM Hubbe

2007-11-01

The ARM Climate Research Facility’s (ACRF) Aerial Vehicle Program (AVP) will deploy an intensive cloud and aerosol observing system to the ARM North Slope of Alaska (NSA) locale for a five week Indirect and Semi-Direct Aerosol Campaign (ISDAC) during period 29 March through 30 April 2008. The deployment period is within the International Polar Year, thus contributing to and benefiting from the many ancillary observing systems collecting data synergistically. We will deploy the Canadian National Research Council Convair 580 aircraft to measure temperature, humidity, total particle number, aerosol size distribution, single particle composition, concentrations of cloud condensation nuclei and icemore » nuclei, optical scattering and absorption, updraft velocity, cloud liquid water and ice contents, cloud droplet and crystal size distributions, cloud particle shape, and cloud extinction. In addition to these aircraft measurements, ISDAC will deploy two instruments at the ARM site in Barrow: a spectroradiometer to retrieve cloud optical depth and effective radius, and a tandem differential mobility analyzer to measure the aerosol size distribution and hygroscopicity. By using many of the same instruments used during Mixed-Phase Arctic Cloud Experiment (M-PACE), conducted in October 2004, we will be able to contrast the arctic aerosol and cloud properties during the fall and spring transitions. The aerosol measurements can be used in cloud models driven by objectively analyzed boundary conditions to test whether the cloud models can simulate the aerosol influence on the clouds. The influence of aerosol and boundary conditions on the simulated clouds can be separated by running the cloud models with all four combinations of M-PACE and ISDAC aerosol and boundary conditions: M-PACE aerosol and boundary conditions, M-PACE aerosol and ISDAC boundary conditions, ISDAC aerosol and M-PACE boundary conditions, and ISDAC aerosol and boundary conditions. ISDAC and M-PACE boundary conditions are likely to be very different because of the much more extensive ocean water during M-PACE. The uniformity of the surface conditions during ISDAC greatly simplifies the objective analysis (surface fluxes and precipitation are very weak), so that it can largely rely on the European Centre for Medium-Range Weather Forecasts analysis. The aerosol measurements can also be used as input to the cloud models and to evaluate the aerosol retrievals. By running the cloud models with and without solar absorption by the aerosols, we can determine the semidirect effect of the aerosol on the clouds.« less

Large Scale Ice Water Path and 3-D Ice Water Content

DOE Data Explorer

Liu, Guosheng

2008-01-15

Cloud ice water concentration is one of the most important, yet poorly observed, cloud properties. Developing physical parameterizations used in general circulation models through single-column modeling is one of the key foci of the ARM program. In addition to the vertical profiles of temperature, water vapor and condensed water at the model grids, large-scale horizontal advective tendencies of these variables are also required as forcing terms in the single-column models. Observed horizontal advection of condensed water has not been available because the radar/lidar/radiometer observations at the ARM site are single-point measurement, therefore, do not provide horizontal distribution of condensed water. The intention of this product is to provide large-scale distribution of cloud ice water by merging available surface and satellite measurements. The satellite cloud ice water algorithm uses ARM ground-based measurements as baseline, produces datasets for 3-D cloud ice water distributions in a 10 deg x 10 deg area near ARM site. The approach of the study is to expand a (surface) point measurement to an (satellite) areal measurement. That is, this study takes the advantage of the high quality cloud measurements at the point of ARM site. We use the cloud characteristics derived from the point measurement to guide/constrain satellite retrieval, then use the satellite algorithm to derive the cloud ice water distributions within an area, i.e., 10 deg x 10 deg centered at ARM site.

FDTD calculations of SAR for child voxel models in different postures between 10 MHz and 3 GHz.

PubMed

Findlay, R P; Lee, A-K; Dimbylow, P J

2009-08-01

Calculations of specific energy absorption rate (SAR) have been performed on the rescaled NORMAN 7-y-old voxel model and the Electronics and Telecommunications Research Institute (ETRI) child 7-y-old voxel model in the standing arms down, arms up and sitting postures. These calculations were for plane-wave exposure under isolated and grounded conditions between 10 MHz and 3 GHz. It was found that there was little difference at each resonant frequency between the whole-body averaged SAR values calculated for the NORMAN and ETRI 7-y-old models for each of the postures studied. However, when compared with the arms down posture, raising the arms increased the SAR by up to 25%. Electric field values required to produce the International Commission on Non-Ionizing Radiation Protection and Institute of Electrical and Electronic Engineers public basic restriction were calculated, and compared with reference levels for the different child models and postures. These showed that, under certain worst-case exposure conditions, the reference levels may not be conservative.

A Model Evaluation Data Set for the Tropical ARM Sites

DOE Data Explorer

Jakob, Christian

2008-01-15

This data set has been derived from various ARM and external data sources with the main aim of providing modelers easy access to quality controlled data for model evaluation. The data set contains highly aggregated (in time) data from a number of sources at the tropical ARM sites at Manus and Nauru. It spans the years of 1999 and 2000. The data set contains information on downward surface radiation; surface meteorology, including precipitation; atmospheric water vapor and cloud liquid water content; hydrometeor cover as a function of height; and cloud cover, cloud optical thickness and cloud top pressure information provided by the International Satellite Cloud Climatology Project (ISCCP).

Lidar Comparison for GoAmazon 2014/15 Field Campaign Report

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

Barbosa, Henrique MJ; Barja, B; Landulfo, E

2016-04-01

The Observations and Modeling of the Green Ocean Amazon 2014/15 (GoAmazon 2014/15) experiment uses the city of Manaus, Amazonas (AM), Brazil, in the setting of the surrounding green ocean as a natural laboratory for understanding the effects of present and future anthropogenic pollution on the aerosol and cloud life cycle in the tropics. The U.S. Department of Energy (DOE) supported this experiment through the deployment of the Atmospheric Radiation Measurement (ARM) Climate Research Facility’s first Mobile Facility (AMF-1) in the city of Manacapuru, which is 100 km downwind of Manaus, from January 1 2014 to December 31 2015. During themore » second Intensive Operational Period (IOP) from August 15 to October 15 2014, three lidar systems were operated simultaneously at different experimental sites, and an instrument comparison campaign was carried out during the period October 4 to 10, during which the mobile lidar system from Instituto de Pesquisas Energéticas e Nucleares-Universidade de São Paulo was brought from the T2 site (Iranduba) to the other sites (T3 [Manacapuru] and then T0e-Embrapa). In this report we present the data collected by the mobile lidar system at the DOE-ARM site and compare its measurements with those from the micro-pulse lidar system running at that site.« less

The Doe Water Cycle Pilot Study.

NASA Astrophysics Data System (ADS)

Miller, N. L.; King, A. W.; Miller, M. A.; Springer, E. P.; Wesely, M. L.; Bashford, K. E.; Conrad, M. E.; Costigan, K.; Foster, P. N.; Gibbs, H. K.; Jin, J.; Klazura, J.; Lesht, B. M.; Machavaram, M. V.; Pan, F.; Song, J.; Troyan, D.; Washington-Allen, R. A.

2005-03-01

A Department of Energy (DOE) multilaboratory Water Cycle Pilot Study (WCPS) investigated components of the local water budget at the Walnut River watershed in Kansas to study the relative importance of various processes and to determine the feasibility of observational water budget closure. An extensive database of local meteorological time series and land surface characteristics was compiled. Numerical simulations of water budget components were generated and, to the extent possible, validated for three nested domains within the Southern Great Plains-the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Cloud Atmospheric Radiation Testbed (CART), the Walnut River watershed (WRW), and the Whitewater watershed (WW), in Kansas.A 2-month intensive observation period (IOP) was conducted to gather extensive observations relevant to specific details of the water budget, including finescale precipitation, streamflow, and soil moisture measurements that were not made routinely by other programs. Event and seasonal water isotope (d18O, dD) sampling in rainwater, streams, soils, lakes, and wells provided a means of tracing sources and sinks within and external to the WW, WRW, and the ARM CART domains. The WCPS measured changes in the leaf area index for several vegetation types, deep groundwater variations at two wells, and meteorological variables at a number of sites in the WRW. Additional activities of the WCPS include code development toward a regional climate model that includes water isotope processes, soil moisture transect measurements, and water-level measurements in groundwater wells.

An ensemble constrained variational analysis of atmospheric forcing data and its application to evaluate clouds in CAM5: Ensemble 3DCVA and Its Application

DOE PAGES

Tang, Shuaiqi; Zhang, Minghua; Xie, Shaocheng

2016-01-05

Large-scale atmospheric forcing data can greatly impact the simulations of atmospheric process models including Large Eddy Simulations (LES), Cloud Resolving Models (CRMs) and Single-Column Models (SCMs), and impact the development of physical parameterizations in global climate models. This study describes the development of an ensemble variationally constrained objective analysis of atmospheric large-scale forcing data and its application to evaluate the cloud biases in the Community Atmospheric Model (CAM5). Sensitivities of the variational objective analysis to background data, error covariance matrix and constraint variables are described and used to quantify the uncertainties in the large-scale forcing data. Application of the ensemblemore » forcing in the CAM5 SCM during March 2000 intensive operational period (IOP) at the Southern Great Plains (SGP) of the Atmospheric Radiation Measurement (ARM) program shows systematic biases in the model simulations that cannot be explained by the uncertainty of large-scale forcing data, which points to the deficiencies of physical parameterizations. The SCM is shown to overestimate high clouds and underestimate low clouds. These biases are found to also exist in the global simulation of CAM5 when it is compared with satellite data.« less

An ensemble constrained variational analysis of atmospheric forcing data and its application to evaluate clouds in CAM5: Ensemble 3DCVA and Its Application

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

Tang, Shuaiqi; Zhang, Minghua; Xie, Shaocheng

Large-scale atmospheric forcing data can greatly impact the simulations of atmospheric process models including Large Eddy Simulations (LES), Cloud Resolving Models (CRMs) and Single-Column Models (SCMs), and impact the development of physical parameterizations in global climate models. This study describes the development of an ensemble variationally constrained objective analysis of atmospheric large-scale forcing data and its application to evaluate the cloud biases in the Community Atmospheric Model (CAM5). Sensitivities of the variational objective analysis to background data, error covariance matrix and constraint variables are described and used to quantify the uncertainties in the large-scale forcing data. Application of the ensemblemore » forcing in the CAM5 SCM during March 2000 intensive operational period (IOP) at the Southern Great Plains (SGP) of the Atmospheric Radiation Measurement (ARM) program shows systematic biases in the model simulations that cannot be explained by the uncertainty of large-scale forcing data, which points to the deficiencies of physical parameterizations. The SCM is shown to overestimate high clouds and underestimate low clouds. These biases are found to also exist in the global simulation of CAM5 when it is compared with satellite data.« less

Stochastic Models for Precipitable Water in Convection

NASA Astrophysics Data System (ADS)

Leung, Kimberly

Atmospheric precipitable water vapor (PWV) is the amount of water vapor in the atmosphere within a vertical column of unit cross-sectional area and is a critically important parameter of precipitation processes. However, accurate high-frequency and long-term observations of PWV in the sky were impossible until the availability of modern instruments such as radar. The United States Department of Energy (DOE)'s Atmospheric Radiation Measurement (ARM) Program facility made the first systematic and high-resolution observations of PWV at Darwin, Australia since 2002. At a resolution of 20 seconds, this time series allowed us to examine the volatility of PWV, including fractal behavior with dimension equal to 1.9, higher than the Brownian motion dimension of 1.5. Such strong fractal behavior calls for stochastic differential equation modeling in an attempt to address some of the difficulties of convective parameterization in various kinds of climate models, ranging from general circulation models (GCM) to weather research forecasting (WRF) models. This important observed data at high resolution can capture the fractal behavior of PWV and enables stochastic exploration into the next generation of climate models which considers scales from micrometers to thousands of kilometers. As a first step, this thesis explores a simple stochastic differential equation model of water mass balance for PWV and assesses accuracy, robustness, and sensitivity of the stochastic model. A 1000-day simulation allows for the determination of the best-fitting 25-day period as compared to data from the TWP-ICE field campaign conducted out of Darwin, Australia in early 2006. The observed data and this portion of the simulation had a correlation coefficient of 0.6513 and followed similar statistics and low-resolution temporal trends. Building on the point model foundation, a similar algorithm was applied to the National Center for Atmospheric Research (NCAR)'s existing single-column model as a test-of-concept for eventual inclusion in a general circulation model. The stochastic scheme was designed to be coupled with the deterministic single-column simulation by modifying results of the existing convective scheme (Zhang-McFarlane) and was able to produce a 20-second resolution time series that effectively simulated observed PWV, as measured by correlation coefficient (0.5510), fractal dimension (1.9), statistics, and visual examination of temporal trends. Results indicate that simulation of a highly volatile time series of observed PWV is certainly achievable and has potential to improve prediction capabilities in climate modeling. Further, this study demonstrates the feasibility of adding a mathematics- and statistics-based stochastic scheme to an existing deterministic parameterization to simulate observed fractal behavior.

Primary reaction control system/remote manipulator system interaction with loaded arm. Space shuttle engineering and operations support

NASA Technical Reports Server (NTRS)

Taylor, E. C.; Davis, J. D.

1978-01-01

A study of the interaction between the orbiter primary reaction control system (PRCS) and the remote manipulator system (RMS) with a loaded arm is documented. This analysis was performed with the Payload Deployment and Retrieval Systems Simulation (PDRSS) program with the passive arm bending option. The passive-arm model simulates the arm as massless elastic links with locked joints. The study was divided into two parts. The first part was the evaluation of the response of the arm to step inputs (i.e. constant jet torques) about each of the orbiter body axes. The second part of the study was the evaluation of the response of the arm to minimum impulse primary RCS jet firings with both single pulse and pulse train inputs.

Sensitivity of tropical convection in cloud-resolving WRF simulations to model physics and forcing procedures

NASA Astrophysics Data System (ADS)

Endo, S.; Lin, W.; Jackson, R. C.; Collis, S. M.; Vogelmann, A. M.; Wang, D.; Oue, M.; Kollias, P.

2017-12-01

Tropical convection is one of the main drivers of the climate system and recognized as a major source of uncertainty in climate models. High-resolution modeling is performed with a focus on the deep convection cases during the active monsoon period of the TWP-ICE field campaign to explore ways to improve the fidelity of convection permitting tropical simulations. Cloud resolving model (CRM) simulations are performed with WRF modified to apply flexible configurations for LES/CRM simulations. We have enhanced the capability of the forcing module to test different implementations of large-scale vertical advective forcing, including a function for optional use of large-scale thermodynamic profiles and a function for the condensate advection. The baseline 3D CRM configurations are, following Fridlind et al. (2012), driven by observationally-constrained ARM forcing and tested with diagnosed surface fluxes and fixed sea-surface temperature and prescribed aerosol size distributions. After the spin-up period, the simulations follow the observed precipitation peaks associated with the passages of precipitation systems. Preliminary analysis shows that the simulation is generally not sensitive to the treatment of the large-scale vertical advection of heat and moisture, while more noticeable changes in the peak precipitation rate are produced when thermodynamic profiles above the boundary layer were nudged to the reference profiles from the forcing dataset. The presentation will explore comparisons with observationally-based metrics associated with convective characteristics and examine the model performance with a focus on model physics, doubly-periodic vs. nested configurations, and different forcing procedures/sources. A radar simulator will be used to understand possible uncertainties in radar-based retrievals of convection properties. Fridlind, A. M., et al. (2012), A comparison of TWP-ICE observational data with cloud-resolving model results, J. Geophys. Res., 117, D05204, doi:10.1029/2011JD016595.

A numerical investigation of flow around octopus-like arms: near-wake vortex patterns and force development.

PubMed

Kazakidi, A; Vavourakis, V; Tsakiris, D P; Ekaterinaris, J A

2015-01-01

The fluid dynamics of cephalopods has so far received little attention in the literature, due to their complexity in structure and locomotion. The flow around octopuses, in particular, can be complicated due to their agile and dexterous arms, which frequently display some of the most diverse mechanisms of motion. The study of this flow amounts to a specific instance of the hydrodynamics problem for rough tapered cylinder geometries. The outstanding manipulative and locomotor skills of octopuses could inspire the development of advanced robotic arms, able to operate in fluid environments. Our primary aim was to study the hydrodynamic characteristics of such bio-inspired robotic models and to derive the hydrodynamic force coefficients as a concise description of the vortical flow effects. Utilizing computational fluid dynamic methods, the coefficients were computed on realistic morphologies of octopus-like arm models undergoing prescribed solid-body movements; such motions occur in nature for short durations in time, e.g. during reaching movements and exploratory behaviors. Numerical simulations were performed on translating, impulsively rotating, and maneuvering arms, around which the flow field structures were investigated. The results reveal in detail the generation of complex vortical flow structures around the moving arms. Hydrodynamic forces acting on a translating arm depend on the angle of incidence; forces generated during impulsive rotations of the arms are independent of their exact morphology and the angle of rotation; periodic motions based on a slow recovery and a fast power stroke are able to produce considerable propulsive thrust while harmonic motions are not. Parts of these results have been employed in bio-inspired models of underwater robotic mechanisms. This investigation may further assist elucidating the hydrodynamics underlying aspects of octopus locomotion and exploratory behaviors.

ARM Research in the Equatorial Western Pacific: A Decade and Counting

NASA Technical Reports Server (NTRS)

Long, C. N.; McFarlane, S. A.; DelGenio, A.; Minnis, P.; Ackerman, T. S.; Mather, J.; Comstock, J.; Mace, G. G.; Jensen, M.; Jakob, C.

2013-01-01

The tropical western Pacific (TWP) is an important climatic region. Strong solar heating, warm sea surface temperatures, and the annual progression of the intertropical convergence zone (ITCZ) across this region generate abundant convective systems, which through their effects on the heat and water budgets have a profound impact on global climate and precipitation. In order to accurately evaluate tropical cloud systems in models, measurements of tropical clouds, the environment in which they reside, and their impact on the radiation and water budgets are needed. Because of the remote location, ground-based datasets of cloud, atmosphere, and radiation properties from the TWP region have come primarily from short-term field experiments. While providing extremely useful information on physical processes, these short-term datasets are limited in statistical and climatological information. To provide longterm measurements of the surface radiation budget in the tropics and the atmospheric properties that affect it, the Atmospheric Radiation Measurement program established a measurement site on Manus Island, Papua New Guinea, in 1996 and on the island republic of Nauru in late 1998. These sites provide unique datasets now available for more than 10 years on Manus and Nauru. This article presents examples of the scientific use of these datasets including characterization of cloud properties, analysis of cloud radiative forcing, model studies of tropical clouds and processes, and validation of satellite algorithms. New instrumentation recently installed at the Manus site will provide expanded opportunities for tropical atmospheric science.

Multi-Scale Modeling of an Integrated 3D Braided Composite with Applications to Helicopter Arm

NASA Astrophysics Data System (ADS)

Zhang, Diantang; Chen, Li; Sun, Ying; Zhang, Yifan; Qian, Kun

2017-10-01

A study is conducted with the aim of developing multi-scale analytical method for designing the composite helicopter arm with three-dimensional (3D) five-directional braided structure. Based on the analysis of 3D braided microstructure, the multi-scale finite element modeling is developed. Finite element analysis on the load capacity of 3D five-directional braided composites helicopter arm is carried out using the software ABAQUS/Standard. The influences of the braiding angle and loading condition on the stress and strain distribution of the helicopter arm are simulated. The results show that the proposed multi-scale method is capable of accurately predicting the mechanical properties of 3D braided composites, validated by the comparison the stress-strain curves of meso-scale RVCs. Furthermore, it is found that the braiding angle is an important factor affecting the mechanical properties of 3D five-directional braided composite helicopter arm. Based on the optimized structure parameters, the nearly net-shaped composite helicopter arm is fabricated using a novel resin transfer mould (RTM) process.

Validating Satellite-Retrieved Cloud Properties for Weather and Climate Applications

NASA Astrophysics Data System (ADS)

Minnis, P.; Bedka, K. M.; Smith, W., Jr.; Yost, C. R.; Bedka, S. T.; Palikonda, R.; Spangenberg, D.; Sun-Mack, S.; Trepte, Q.; Dong, X.; Xi, B.

2014-12-01

Cloud properties determined from satellite imager radiances are increasingly used in weather and climate applications, particularly in nowcasting, model assimilation and validation, trend monitoring, and precipitation and radiation analyses. The value of using the satellite-derived cloud parameters is determined by the accuracy of the particular parameter for a given set of conditions, such as viewing and illumination angles, surface background, and cloud type and structure. Because of the great variety of those conditions and of the sensors used to monitor clouds, determining the accuracy or uncertainties in the retrieved cloud parameters is a daunting task. Sensitivity studies of the retrieved parameters to the various inputs for a particular cloud type are helpful for understanding the errors associated with the retrieval algorithm relative to the plane-parallel world assumed in most of the model clouds that serve as the basis for the retrievals. Real world clouds, however, rarely fit the plane-parallel mold and generate radiances that likely produce much greater errors in the retrieved parameter than can be inferred from sensitivity analyses. Thus, independent, empirical methods are used to provide a more reliable uncertainty analysis. At NASA Langley, cloud properties are being retrieved from both geostationary (GEO) and low-earth orbiting (LEO) satellite imagers for climate monitoring and model validation as part of the NASA CERES project since 2000 and from AVHRR data since 1978 as part of the NOAA CDR program. Cloud properties are also being retrieved in near-real time globally from both GEO and LEO satellites for weather model assimilation and nowcasting for hazards such as aircraft icing. This paper discusses the various independent datasets and approaches that are used to assessing the imager-based satellite cloud retrievals. These include, but are not limited to data from ARM sites, CloudSat, and CALIPSO. This paper discusses the use of the various datasets available, the methods employed to utilize them in the cloud property retrieval validation process, and the results and how they aid future development of the retrieval algorithms. Future needs are also discussed.

A global synthesis of animal phenological responses to climate change

NASA Astrophysics Data System (ADS)

Cohen, Jeremy M.; Lajeunesse, Marc J.; Rohr, Jason R.

2018-03-01

Shifts in phenology are already resulting in disruptions to the timing of migration and breeding, and asynchronies between interacting species1-5. Recent syntheses have concluded that trophic level1, latitude6 and how phenological responses are measured7 are key to determining the strength of phenological responses to climate change. However, researchers still lack a comprehensive framework that can predict responses to climate change globally and across diverse taxa. Here, we synthesize hundreds of published time series of animal phenology from across the planet to show that temperature primarily drives phenological responses at mid-latitudes, with precipitation becoming important at lower latitudes, probably reflecting factors that drive seasonality in each region. Phylogeny and body size are associated with the strength of phenological shifts, suggesting emerging asynchronies between interacting species that differ in body size, such as hosts and parasites and predators and prey. Finally, although there are many compelling biological explanations for spring phenological delays, some examples of delays are associated with short annual records that are prone to sampling error. Our findings arm biologists with predictions concerning which climatic variables and organismal traits drive phenological shifts.

Regional aerosol radiative and hydrological effects over the mid-Atlantic corridor

NASA Astrophysics Data System (ADS)

Creekmore, Torreon N.

A thorough assessment of direct, indirect, and semi-direct influences of aerosols on Earth's energy budget is required to better understand climate and estimate how it may change in the future. Clear-sky surface broadband (measured and modeled) irradiance, spectral aerosol optical depth, heating rate profiles, and non-radiative flux measurements were conducted at a state-of-the-art site, developed by the NOAA-Howard University Center for Atmospheric Sciences (NCAS) program, providing a best estimate of aerosol radiative atmosphere-surface interactions. Methods developed by the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Program were applied to: (1) temporally quantify regional aerosol forcing, (2) to derive an empirical equation describing a relationship between aerosol optical depth and normalized diffuse ratio, (3) evaluate aerosol impacts on atmospheric heating, and (4) evaluate how aerosol forcing impacts may possibly reduce latent and sensible fluxes. Measurements were obtained during the period of May--September for the years of 2005, 2006, and 2007. Atmospheric aerosols are among the key uncertainties affecting the Earth's climate and atmospheric radiative processes. Present-day increases in aerosol concentrations directly, indirectly, and semi-directly impact the Earth's energy budget (i.e., cooling the surface and heating the atmosphere), thereby contributing to climate change. The Howard University Beltsville Site (HUBS) has experienced a greater loss in mean normalized aerosol radiative forcing with time, as observations show a decrease from --0.9 in 2005 to --3.1 and --3.4 W/m2 for 2006 and 2007 respectively, in mean net surface irradiance. The mean normalized aerosol radiative forcing estimated for the period considered was --2.5 W/m2. The reduction in surface solar insolation is due to increased scattering and absorption related to increased aerosol burdens v for the period, promoting surface cooling and atmospheric heating. Calculation of radiative flux and heating rates profiles, which are constrained by HUBS observations, were performed by the 1-D Fu-Liou radiative transfer model to investigate the effect of polluted and pristine aerosol conditions on the surface energy budget and hydrological cycle. For HUBS the surface forcing (--14.2 W/m2) and atmospheric forcing (9.9 W/m2) were significantly larger than the TOA (--4.3 W/m2) radiative forcing. Associated aerosol heating, as well as reduced surface insolation, may lead to increasing near surface static stability, and reduced vertical transport of moisture into the atmospheric boundary layer, and over time, a possible spin-down of the hydrological cycle. It is shown that HUBS provides an ideal opportunity for improving measurements and datasets, thus allowing for both the study and understanding of aerosol impacts on the climate system. Further, results show that in order to provide reference quality data and constrain aerosol radiative effects over land, ground-based research sites must conform to HUBS standards of: (1) instrumentation (e.g. passive and active sensors); (2) operational protocols (e.g. calibration and routine cleaning); (3) rigorous cloud screening protocols; and (4) incorporation of ARM QC and modified FFA algorithms. HUBS surface measurements provides the reference quality data necessary and capability required to help enhance measurements and constrain current uncertainties in estimates of aerosol direct effects over land. Incorporating a combined technique of both active and passive instruments reduced the direct radiative forcing estimates by ˜82 W/m2. The analysis of aerosol effects over HUBS helps continue in bridging the gap of applying measurements for improvement of climate simulations by generating observational products, which describes aerosol and radiation field characteristics in detail.

OLYMPEX Counterflow Spectrometer and Impactor Field Campaign Report

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

Poellot, Michael

The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s ARM Aerial Facility (AAF) Counterflow Spectrometer and Impactor (CSI) probe was flown on the University of North Dakota Cessna Citation research aircraft during the Olympic Mountain Experiment (OLYMPEX). The field campaign took place from November 12 through December 19, 2015, over the Olympic Mountains and coastal waters of Washington State as part of a National Aeronautics and Space Administration (NASA) Global Precipitation Measurement (GPM) validation campaign. The CSI was added to the Citation instrument suite to support the NASA Aerosol-Cloud Ecosystem (ACE) satellite program and flights ofmore » the NASA Lockheed Earth Resources (ER-2) aircraft. ACE funded extra ER-2 flights to focus on clouds that are weakly precipitating, which are also of interest to the DOE Atmospheric System Research (ASR) program.« less

Evaluation of Routine Atmospheric Sounding Measurements Using Unmanned Systems (ERASMUS) Field Campaign Report

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

de Boer, Gijs; Lawrence, Dale; Palo, Scott

The Evaluation of Routine Atmospheric Sounding Measurements using Unmanned Systems (ERASMUS) campaign was proposed with two central goals; to obtain scientifically relevant measurements of quantities related to clouds, aerosols, and radiation, including profiles of temperature, humidity, and aerosol particles, the structure of the arctic atmosphere during transitions between clear and cloudy states, measurements that would allow us to evaluate the performance of retrievals from U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility remote sensors in the Arctic atmosphere, and information on the spatial variability of heat and moisture fluxes from the arctic surface; and to demonstratemore » unmanned aerial system (UAS) capabilities in obtaining measurements relevant to the ARM and ASR programs, particularly for improving our understanding of Arctic clouds and aerosols.« less

Modeling of a field-widened Michelson interferometric filter for application in a high spectral resolution lidar

NASA Astrophysics Data System (ADS)

Liu, Dong; Hostetler, Chris; Cook, Anthony; Miller, Ian; Hair, Johnathan

2011-11-01

High spectral resolution lidars (HSRLs) are increasingly being deployed on aircraft and called for on future space-based missions. The HSRL technique relies on spectral discrimination of the atmospheric backscatter signals to enable independent, unambiguous retrieval of aerosol extinction and backscatter. A compact, monolithic field-widened Michelson interferometer is being developed as the spectral discrimination filter for an HSRL system at NASA Langley Research Center. The interferometer consists of a cubic beam splitter, a solid glass arm, and an air arm. The spacer that connects the air arm mirror to the main part of the interferometer is designed to optimize thermal compensation such that the maximum interference can be tuned with great precision to the transmitted laser wavelength. In this paper, a comprehensive radiometric model for the field-widened Michelson interferometeric spectral filter is presented. The model incorporates the angular distribution and finite cross sectional area of the light source, reflectance of all surfaces, loss of absorption, and lack of parallelism between the air-arm and solid arm, etc. The model can be used to assess the performance of the interferometer and thus it is a useful tool to evaluate performance budgets and to set optical specifications for new designs of the same basic interferometer type.

Force-induced desorption of 3-star polymers: a self-avoiding walk model

NASA Astrophysics Data System (ADS)

Janse van Rensburg, E. J.; Whittington, S. G.

2018-05-01

We consider a simple cubic lattice self-avoiding walk model of 3-star polymers adsorbed at a surface and then desorbed by pulling with an externally applied force. We determine rigorously the free energy of the model in terms of properties of a self-avoiding walk, and show that the phase diagram includes four phases, namely a ballistic phase where the extension normal to the surface is linear in the length, an adsorbed phase and a mixed phase, in addition to the free phase where the model is neither adsorbed nor ballistic. In the adsorbed phase all three branches or arms of the star are adsorbed at the surface. In the ballistic phase two arms of the star are pulled into a ballistic phase, while the remaining arm is in a free phase. In the mixed phase two arms in the star are adsorbed while the third arm is ballistic. The phase boundaries separating the ballistic and mixed phases, and the adsorbed and mixed phases, are both first order phase transitions. The presence of the mixed phase is interesting because it does not occur for pulled, adsorbed self-avoiding walks. In an atomic force microscopy experiment it would appear as an additional phase transition as a function of force.

Graduate student theses supported by DOE`s Environmental Sciences Division

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

Cushman, Robert M.; Parra, Bobbi M.

1995-07-01

This report provides complete bibliographic citations, abstracts, and keywords for 212 doctoral and master`s theses supported fully or partly by the U.S. Department of Energy`s Environmental Sciences Division (and its predecessors) in the following areas: Atmospheric Sciences; Marine Transport; Terrestrial Transport; Ecosystems Function and Response; Carbon, Climate, and Vegetation; Information; Computer Hardware, Advanced Mathematics, and Model Physics (CHAMMP); Atmospheric Radiation Measurement (ARM); Oceans; National Institute for Global Environmental Change (NIGEC); Unmanned Aerial Vehicles (UAV); Integrated Assessment; Graduate Fellowships for Global Change; and Quantitative Links. Information on the major professor, department, principal investigator, and program area is given for each abstract.more » Indexes are provided for major professor, university, principal investigator, program area, and keywords. This bibliography is also available in various machine-readable formats (ASCII text file, WordPerfect{reg_sign} files, and PAPYRUS{trademark} files).« less

Origin of orbital periods in the sedimentary relative paleointensity records

NASA Astrophysics Data System (ADS)

Xuan, Chuang; Channell, James E. T.

2008-08-01

Orbital cycles with 100 kyr and/or 41 kyr periods, detected in some sedimentary normalized remanence (relative paleointensity) records by power spectral analysis or wavelet analysis, have been attributed either to orbital forcing of the geodynamo, or to lithologic contamination. In this study, local wavelet power spectra (LWPS) with significance tests have been calculated for seven relative paleointensity (RPI) records from different regions of the world. The results indicate that orbital periods (100 kyr and/or 41 kyr) are significant in some RPI records during certain time intervals, and are not significant in others. Time intervals where orbital periods are significant are not consistent among the RPI records, implying that orbital periods in these RPI records may not have a common origin such as orbital forcing on the geodynamo. Cross-wavelet power spectra (|XWT|) and squared wavelet coherence (WTC) between RPI records and orbital parameters further indicate that common power exists at orbital periods but is not significantly coherent, and exhibits variable phase relationships, implying that orbital periods in RPI records are not caused directly by orbital forcing. Similar analyses for RPI records and benthic oxygen isotope records from the same sites show significant coherence and constant in-phase relationships during time intervals where orbital periods were significant in the RPI records, indicating that orbital periods in the RPI records are most likely due to climatic 'contamination'. Although common power exists at orbital periods for RPI records and their normalizers with significant coherence during certain time intervals, phase relationships imply that 'contamination' (at orbital periods) is not directly due to the normalizers. Orbital periods are also significant in the NRM intensity records, and 'contamination' in RPI records can be attributed to incomplete normalization of the NRM records. Further tests indicate that 'contamination' is apparently not directly related to physical properties such as density or carbonate content, or to the grain size proxy κARM/ κ. However, WTC between RPI records and the grain size proxy ARM/IRM implies that ARM/IRM does reflect the 'contamination' in some RPI records. It appears that orbital periods were introduced into the NRM records (and have not been normalized when calculating RPI records) through magnetite grain size variations reflected in the ARM/IRM grain size proxy. The orbital power in ARM/IRM for some North Atlantic sites is probably derived from bottom-current velocity variations that are orbitally modulated and are related to the vigor of thermohaline circulation and the production of North Atlantic Deep Water (NADW). In the case of ODP Site 983, the orbital power in RPI appears to exhibit a shift from 41-kyr to 100-kyr period at the mid-Pleistocene climate transition (˜750 ka), reinforcing the climatic origin of these orbital periods. RPI records from the Atlantic and Pacific oceans, and RPI records with orbital periods eliminated by band-pass filters, are highly comparable with each other in the time domain, and are coherent and in-phase in time-frequency space, especially at non-orbital periods, indicating that 'contamination', although present (at orbital periods) is not debilitating to these RPI records as a global signal that is primarily of geomagnetic origin.

Arm span as a proxy measure for height and estimation of nutritional status: a study among Dhimals of Darjeeling in West Bengal India.

PubMed

Datta Banik, Sudip

2011-11-01

This study aimed to understand the interrelationship between height and arm span and also to estimate nutritional status from arm span. In an anthropometric survey conducted among the Dhimals (227 males and 223 females, total = 450) of Naxalbari in West Bengal, India, measurements were recorded in age groups ranging between 10-59 years. Males were taller and had longer arm spans than females. The height-arm span ratio was 0.98-0.99, indicating height to be slightly less than arm span in both sexes. High correlation between these two dimensions was also observed. Regression equations provided a good model for estimating height from arm span (predictor). In all age groups of both sexes, values of standardized coefficient beta exhibited high significance (p ( 0.001). Residuals showed no pattern and were random. No significant difference between height-based body mass index or BMI (body weight/height(2)) and estimated arm span-based BMI (body weight/arm span(2)) was observed in any age group. Arm span was found to be an effective surrogate measure for BMI.

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

AS Koontz; S Choudhury; BD Ermold

The purpose of this report is to provide status of the ingest software used to process instrument data for the Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF). The report is divided into four sections: (1) news about ingests currently under development, (2) current production ingests, (3) future ingest development plans, and (4) information on retired ingests. Please note that datastreams beginning in “xxx” indicate cases where ingests run at multiple ACRF sites, which results in a datastream(s) for each location.

Paradoxies and axioms of science in the creativity of Clim Ivanovich Churyumov

NASA Astrophysics Data System (ADS)

Steklov, A. F.; Vidmachenko, A. P.; Zhilyaev, B. E.; Dashkiev, G. N.; Svyatogorov, O. A.

2017-09-01

Key ideas of K.I. Churyumov and authors of the article on the development of astronomical research in Ukraine, creation of Ukrainian Institute for Advanced Studies; concerning special directions of interaction of astronomical observatories and the Armed Forces of Ukraine during the period of hybrid wars and methods of solving certain tasks of astrobiology, life of people on the planet Earth taking into account monthly rhythms and climatic seasons.

Aerosol and Cloud Experiments in Eastern North Atlantic (ACE-ENA) Science Plan

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

Wang, Jian; Dong, Xiquan; Wood, Robert

With their extensive coverage, low clouds greatly impact global climate. Presently, low clouds are poorly represented in global climate models (GCMs), and the response of low clouds to changes in atmospheric greenhouse gases and aerosols remains the major source of uncertainty in climate simulations. The poor representations of low clouds in GCMs are in part due to inadequate observations of their microphysical and macrophysical structures, radiative effects, and the associated aerosol distribution and budget in regions where the aerosol impact is the greatest. The Eastern North Atlantic (ENA) is a region of persistent but diverse subtropical marine boundary-layer (MBL) clouds,more » whose albedo and precipitation are highly susceptible to perturbations in aerosol properties. Boundary-layer aerosol in the ENA region is influenced by a variety of sources, leading to strong variations in cloud condensation nuclei (CCN) concentration and aerosol optical properties. Recently a permanent ENA site was established by the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility on Graciosa Island in the Azores, providing invaluable information on MBL aerosol and low clouds. At the same time, the vertical structures and horizontal variabilities of aerosol, trace gases, cloud, drizzle, and atmospheric thermodynamics are critically needed for understanding and quantifying the budget of MBL aerosol, the radiative properties, precipitation efficiency, and lifecycle of MBL clouds, and the cloud response to aerosol perturbations. Much of this data can be obtained only through aircraft-based measurements. In addition, the interconnected aerosol and cloud processes are best investigated by a study involving simultaneous in situ aerosol, cloud, and thermodynamics measurements. Furthermore, in situ measurements are also necessary for validating and improving ground-based retrieval algorithms at the ENA site. This project is motivated by the need for comprehensive in situ characterizations of boundary-layer structure, and associated vertical distributions and horizontal variabilities of low clouds and aerosol over the Azores. ARM Aerial Facility (AAF) Gulfstream-1 (G-1) aircraft will be deployed at the ENA site during two intensive operational periods (IOPs) of early summer (June to July) of 2017 and winter (January to February) of 2018, respectively. Deployments during both seasons allow for examination of key aerosol and cloud processes under a variety of representative meteorological and cloud conditions. The science themes for the deployments include: 1) Budget of MBL CCN and its seasonal variation; 2) Effects of aerosol on cloud and precipitation; 3) Cloud microphysical and macrophysical structures, and entrainment mixing; 4) Advancing retrievals of turbulence, cloud, and drizzle; and 5) Model evaluation and processes studies. A key advantage of the deployments is the strong synergy between the measurements onboard the G-1 and the routine measurements at the ENA site, including state-of-the-art profiling and scanning radars. The 3D cloud structures provided by the scanning radars will put the detailed in situ measurements into mesoscale and cloud lifecycle contexts. On the other hand, high quality in situ measurements will enable validation and improvements of ground-based retrieval algorithms at the ENA site, leading to high-quality and statistically robust data sets from the routine measurements. The deployments, combined with the routine measurements at the ENA site, will have a long lasting impact on the research and modeling of low clouds and aerosols in the remote marine environment.« less

A Path Where No Man Thought; Nuclear Winter and the End of the Arms Race

NASA Astrophysics Data System (ADS)

Brasseur, Guy

In 1982, Paul Crutzen, Max Planck Institute for Chemistry, Mainz, Germany, and John Birks, University of Colorado, Boulder, published a provocative paper suggesting that the smoke from the fires triggered by potential massive nuclear explosions would generate profound changes in the chemical composition and physical state of the Earth's atmosphere. A year later, a group of five scientists, Richard Turco, Brian Toon, Tom Ackerman, Jim Pollack, and Carl Sagan, showed, on the basis of model calculations, that the Earth would cool significantly following nuclear explosions and that the climatic impacts of a nuclear war would affect not only the country attacked but also the aggressor. This group, which received the acronym of TTAPS, showed that the number of fatalities resulting from the indirect climatic perturbations could be at least as large as the number of humans directly killed by the explosions. Two of the authors of the TTAPS theory, Carl Sagan and Richard Turco, have summarized 10 years of extensive research and public controversy following the publication of the nuclear winter hypothesis. In their fascinating book they try to analyze how the concept of nuclear winter has changed the attitude of the political world, has contributed to the improvement of political relations between the two superpowers, and has initiated a revision of geopolitical and military theories.

Dependence of muscle moment arms on in-vivo three-dimensional kinematics of the knee

PubMed Central

Navacchia, Alessandro; Kefala, Vasiliki; Shelburne, Kevin B.

2016-01-01

Quantification of muscle moment arms is important for clinical evaluation of muscle pathology and treatment, and for estimating muscle and joint forces in musculoskeletal models. Moment arms estimated with musculoskeletal models often assume a default motion of the knee derived from measurements of passive cadaveric flexion. However, knee kinematics are unique to each person and activity. The objective of this study was to estimate moment arms of the knee muscles with in vivo subject- and activity-specific kinematics from seven healthy subjects performing seated knee extension and single-leg lunge to show changes between subjects and activities. 3D knee motion was measured with a high-speed stereo-radiography system. Moment arms of ten muscles were estimated in OpenSim by replacing the default knee motion with in vivo measurements. Estimated inter-subject moment arm variability was similar to previously reported in vitro measurements. RMS deviations up to 9.0 mm (35.2% of peak value) were observed between moment arms estimated with subject-specific knee extension and passive cadaveric motion. The degrees of freedom that most impacted inter-activity differences were superior/inferior and anterior/posterior translations. Musculoskeletal simulations used to estimate in vivo muscle forces and joint loads may provide significantly different results when subject- and activity-specific kinematics are implemented. PMID:27620064

Dependence of Muscle Moment Arms on In Vivo Three-Dimensional Kinematics of the Knee.

PubMed

Navacchia, Alessandro; Kefala, Vasiliki; Shelburne, Kevin B

2017-03-01

Quantification of muscle moment arms is important for clinical evaluation of muscle pathology and treatment, and for estimating muscle and joint forces in musculoskeletal models. Moment arms estimated with musculoskeletal models often assume a default motion of the knee derived from measurements of passive cadaveric flexion. However, knee kinematics are unique to each person and activity. The objective of this study was to estimate moment arms of the knee muscles with in vivo subject- and activity-specific kinematics from seven healthy subjects performing seated knee extension and single-leg lunge to show changes between subjects and activities. 3D knee motion was measured with a high-speed stereo-radiography system. Moment arms of ten muscles were estimated in OpenSim by replacing the default knee motion with in vivo measurements. Estimated inter-subject moment arm variability was similar to previously reported in vitro measurements. RMS deviations up to 9.0 mm (35.2% of peak value) were observed between moment arms estimated with subject-specific knee extension and passive cadaveric motion. The degrees of freedom that most impacted inter-activity differences were superior/inferior and anterior/posterior translations. Musculoskeletal simulations used to estimate in vivo muscle forces and joint loads may provide significantly different results when subject- and activity-specific kinematics are implemented.

Sample size determinations for group-based randomized clinical trials with different levels of data hierarchy between experimental and control arms.

PubMed

Heo, Moonseong; Litwin, Alain H; Blackstock, Oni; Kim, Namhee; Arnsten, Julia H

2017-02-01

We derived sample size formulae for detecting main effects in group-based randomized clinical trials with different levels of data hierarchy between experimental and control arms. Such designs are necessary when experimental interventions need to be administered to groups of subjects whereas control conditions need to be administered to individual subjects. This type of trial, often referred to as a partially nested or partially clustered design, has been implemented for management of chronic diseases such as diabetes and is beginning to emerge more commonly in wider clinical settings. Depending on the research setting, the level of hierarchy of data structure for the experimental arm can be three or two, whereas that for the control arm is two or one. Such different levels of data hierarchy assume correlation structures of outcomes that are different between arms, regardless of whether research settings require two or three level data structure for the experimental arm. Therefore, the different correlations should be taken into account for statistical modeling and for sample size determinations. To this end, we considered mixed-effects linear models with different correlation structures between experimental and control arms to theoretically derive and empirically validate the sample size formulae with simulation studies.

Modified compensation algorithm of lever-arm effect and flexural deformation for polar shipborne transfer alignment based on improved adaptive Kalman filter

NASA Astrophysics Data System (ADS)

Wang, Tongda; Cheng, Jianhua; Guan, Dongxue; Kang, Yingyao; Zhang, Wei

2017-09-01

Due to the lever-arm effect and flexural deformation in the practical application of transfer alignment (TA), the TA performance is decreased. The existing polar TA algorithm only compensates a fixed lever-arm without considering the dynamic lever-arm caused by flexural deformation; traditional non-polar TA algorithms also have some limitations. Thus, the performance of existing compensation algorithms is unsatisfactory. In this paper, a modified compensation algorithm of the lever-arm effect and flexural deformation is proposed to promote the accuracy and speed of the polar TA. On the basis of a dynamic lever-arm model and a noise compensation method for flexural deformation, polar TA equations are derived in grid frames. Based on the velocity-plus-attitude matching method, the filter models of polar TA are designed. An adaptive Kalman filter (AKF) is improved to promote the robustness and accuracy of the system, and then applied to the estimation of the misalignment angles. Simulation and experiment results have demonstrated that the modified compensation algorithm based on the improved AKF for polar TA can effectively compensate the lever-arm effect and flexural deformation, and then improve the accuracy and speed of TA in the polar region.

The Implementation and Testing of a Robotic Arm on an Autonomous Vehicle

DTIC Science & Technology

2007-12-01

FIGURES Figure 1. BigFoot . .............................................................................................................2 Figure 2...Arm. ............................................................31 Figure 29. BigFoot launched a shaped charge model on the suspected IED...work with BigFoot . I would also like to thank you to LTCD Kirk Volland for his assistance in the implementation and testing of a robotic arm. I thank

Evaluation of computational endomicroscopy architectures for minimally-invasive optical biopsy

NASA Astrophysics Data System (ADS)

Dumas, John P.; Lodhi, Muhammad A.; Bajwa, Waheed U.; Pierce, Mark C.

2017-02-01

We are investigating compressive sensing architectures for applications in endomicroscopy, where the narrow diameter probes required for tissue access can limit the achievable spatial resolution. We hypothesize that the compressive sensing framework can be used to overcome the fundamental pixel number limitation in fiber-bundle based endomicroscopy by reconstructing images with more resolvable points than fibers in the bundle. An experimental test platform was assembled to evaluate and compare two candidate architectures, based on introducing a coded amplitude mask at either a conjugate image or Fourier plane within the optical system. The benchtop platform consists of a common illumination and object path followed by separate imaging arms for each compressive architecture. The imaging arms contain a digital micromirror device (DMD) as a reprogrammable mask, with a CCD camera for image acquisition. One arm has the DMD positioned at a conjugate image plane ("IP arm"), while the other arm has the DMD positioned at a Fourier plane ("FP arm"). Lenses were selected and positioned within each arm to achieve an element-to-pixel ratio of 16 (230,400 mask elements mapped onto 14,400 camera pixels). We discuss our mathematical model for each system arm and outline the importance of accounting for system non-idealities. Reconstruction of a 1951 USAF resolution target using optimization-based compressive sensing algorithms produced images with higher spatial resolution than bicubic interpolation for both system arms when system non-idealities are included in the model. Furthermore, images generated with image plane coding appear to exhibit higher spatial resolution, but more noise, than images acquired through Fourier plane coding.

UWHS Climate Science: Uniting University Scientists and High School Teachers in the Development and Implementation of a Dual-Credit STEM-Focused Curriculum

NASA Astrophysics Data System (ADS)

Bertram, M. A.; Thompson, L.; Ackerman, T. P.

2012-12-01

The University of Washington is adapting a popular UW Atmospheric Sciences course on Climate and Climate Change for the high school environment. In the process, a STEM-focused teaching and learning community has formed. With the support of NASA Global Climate Change Education 20 teachers have participated in an evolving professional development program that brings those actively engaged in research together with high school teachers passionate about bringing a formal climate science course into the high school. Over a period of several months participating teachers work through the UW course homework and delve deeply into specific subject areas. Then, during a week-long summer institute, scientists bring their particular expertise (e.g. radiation, modeling) to the high school teachers through lectures or labs. Together they identify existing lectures, textbook material and peer-reviewed resources and labs available through the internet that can be used to effectively teach the UW material to the high school students. Through this process the scientists learn how to develop teaching materials around their area of expertise, teachers engage deeply in the subject matter, and both the university and high school teachers are armed with the tools to effectively teach a STEM-focused introductory course in climate science. To date 12 new hands-on modules have been completed or are under development, exploring ice-cores, isotopes, historical temperature trends, energy balance, climate models, and more. Two modules have been tested in the classroom and are ready for peer-review through well-respected national resources such as CLEAN or the National Earth Science Teachers Association; three others are complete and will be implemented in a high school classroom this year, and the remainder under various stages of development. The UWHS ATMS 211 course was piloted in two APES (Advanced Placement Environmental Science classrooms) in Washington State in 2011/2012. The high school course used the UW Atmospheric Sciences curriculum, exams, and textbook (The Earth System, 3rd edition, Kump, Kasting and Crane, 2010), and one of the hands-on modules. Communication with these instructors during the year helped us define assessment strategies and to identify challenges of bringing the material into the high school classroom. This knowledge will be shared with teachers during our summer 2012 workshop and will inform approaches to teaching the course in 2012/2013. Proposed formats for implementation include year-long courses, using the APES/Climate format of 2011/2012, a union of Oceanography and Climate content, or in the context of an engineering course. Our initial vision was for a stand-alone semester or year-long course in climate science, incorporating excel and data handling as a learning tool and a suite of hands-on learning opportunities. Yet, the creative approaches to implementation of a new course in the schools, together with the breadth and depth of the UW curriculum and the Kump et al. 2010 textbook, have resulted in diverse educational approaches for bringing climate science into the high school.

Phoenix Robotic Arm Rasp

NASA Image and Video Library

2008-07-15

This photograph shows the rasp protruding from the back of the scoop on NASA Phoenix Mars Lander Robotic Arm engineering model in the Payload Interoperability Testbed at the University of Arizona, Tucson.

Strengthening malaria service delivery through supportive supervision and community mobilization in an endemic Indian setting: an evaluation of nested delivery models.

PubMed

Das, Ashis; Friedman, Jed; Kandpal, Eeshani; Ramana, Gandham N V; Gupta, Rudra Kumar Das; Pradhan, Madan M; Govindaraj, Ramesh

2014-12-08

Malaria continues to be a prominent global public health challenge. This study tested the effectiveness of two service delivery models for reducing the malaria burden, e.g. supportive supervision of community health workers (CHW) and community mobilization in promoting appropriate health-seeking behaviour for febrile illnesses in Odisha, India. The study population comprised 120 villages from two purposively chosen malaria-endemic districts, with 40 villages randomly assigned to each of the two treatment arms, one with both supportive supervision and community mobilization and one with community mobilization alone, as well as an observational control arm. Outcome measures included changes in the utilization of bed nets and timely care-seeking for fever from a trained provider compared to the control group. Analysis was by intention-to-treat. Significant improvements were observed in the reported utilization of bed nets in both intervention arms (84.5% in arm A and 82.4% in arm B versus 78.6% in the control arm; p < 0.001). While overall rates of treatment-seeking were equal across study arms, treatment-seeking from a CHW was higher in both intervention arms (28%; p = 0.005 and 27.6%; p = 0.007) than in the control arm (19.2%). Fever cases were significantly more likely to visit a CHW and receive a timely diagnosis of fever in the combined interventions arm than in the control arm (82.1% vs. 67.1%; p = 0.025). Care-seeking from trained providers also increased with a substitution away from untrained providers. Further, fever cases from the combined interventions arm (60.6%; p = 0.004) and the community mobilization arm (59.3%; p = 0.012) were more likely to have received treatment from a skilled provider within 24 hours than fever cases from the control arm (50.1%). In particular, women from the combined interventions arm were more likely to have received timely treatment from a skilled provider (61.6% vs. 47.2%; p = 0.028). A community-based intervention combining the supportive supervision of community health workers with intensive community mobilization and can be effective in improving care-seeking and preventive behaviour and may be used to strengthen the national malaria control programme.

The Action--Reflection--Modelling (ARM) Pedagogical Approach for Teacher Education: A Malaysia-UK Project

ERIC Educational Resources Information Center

Jarvis, Joy; Dickerson, Claire; Thomas, Kit; Graham, Sally

2014-01-01

This article presents the Action--Reflection--Modelling (ARM) pedagogical approach for teacher education developed during a Malaysia-UK collaborative project to construct a Bachelor of Education (Honours) degree programme in Primary Mathematics, with English and Health and Physical Education as minor subjects. The degree programme was written…

76 FR 31457 - Airworthiness Directives; Diamond Aircraft Industries GmbH Model DA 42 Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-01

... Airworthiness Directives; Diamond Aircraft Industries GmbH Model DA 42 Airplanes AGENCY: Federal Aviation... reportedly found on DA 42 Main Landing Gear (MLG) Damper-to-Trailing Arm joints during standard maintenance... DA 42 Main Landing Gear (MLG) Damper-to-Trailing Arm joints during standard maintenance. Depending on...

Ophiuroid robot that self-organizes periodic and non-periodic arm movements.

PubMed

Kano, Takeshi; Suzuki, Shota; Watanabe, Wataru; Ishiguro, Akio

2012-09-01

Autonomous decentralized control is a key concept for understanding the mechanism underlying adaptive and versatile locomotion of animals. Although the design of an autonomous decentralized control system that ensures adaptability by using coupled oscillators has been proposed previously, it cannot comprehensively reproduce the versatility of animal behaviour. To tackle this problem, we focus on using ophiuroids as a simple model that exhibits versatile locomotion including periodic and non-periodic arm movements. Our existing model for ophiuroid locomotion uses an active rotator model that describes both oscillatory and excitatory properties. In this communication, we develop an ophiuroid robot to confirm the validity of this proposed model in the real world. We show that the robot travels by successfully coordinating periodic and non-periodic arm movements in response to external stimuli.

Adaptive tracking for complex systems using reduced-order models

NASA Technical Reports Server (NTRS)

Carnigan, Craig R.

1990-01-01

Reduced-order models are considered in the context of parameter adaptive controllers for tracking workspace trajectories. A dual-arm manipulation task is used to illustrate the methodology and provide simulation results. A parameter adaptive controller is designed to track a payload trajectory using a four-parameter model instead of the full-order, nine-parameter model. Several simulations with different payload-to-arm mass ratios are used to illustrate the capabilities of the reduced-order model in tracking the desired trajectory.

Adaptive tracking for complex systems using reduced-order models

NASA Technical Reports Server (NTRS)

Carignan, Craig R.

1990-01-01

Reduced-order models are considered in the context of parameter adaptive controllers for tracking workspace trajectories. A dual-arm manipulation task is used to illustrate the methodology and provide simulation results. A parameter adaptive controller is designed to track the desired position trajectory of a payload using a four-parameter model instead of a full-order, nine-parameter model. Several simulations with different payload-to-arm mass ratios are used to illustrate the capabilities of the reduced-order model in tracking the desired trajectory.

The Feasibility and Oncological Safety of Axillary Reverse Mapping in Patients with Breast Cancer: A Systematic Review and Meta-Analysis of Prospective Studies

PubMed Central

Han, Chao; Yang, Ben; Zuo, Wen-Shu; Zheng, Gang; Yang, Li; Zheng, Mei-Zhu

2016-01-01

Objective The axillary reverse mapping (ARM) technique has recently been developed to prevent lymphedema by preserving the arm lymphatic drainage during sentinel lymph node biopsy (SLNB) or axillary lymph node dissection (ALND) procedures. The objective of this systematic review and meta-analysis was to evaluate the feasibility and oncological safety of ARM. Methods We searched Medline, Embase, Web of science, Scopus, and the Cochrane Library for relevant prospective studies. The identification rate of ARM nodes, the crossover rate of SLN-ARM nodes, the proportion of metastatic ARM nodes, and the incidence of complications were pooled into meta-analyses by the random-effects model. Results A total of 24 prospective studies were included into meta-analyses, of which 11 studies reported ARM during SLNB, and 18 studies reported ARM during SLNB. The overall identification rate of ARM nodes was 38.2% (95% CI 32.9%-43.8%) during SLNB and 82.8% (78.0%-86.6%) during ALND, respectively. The crossover rate of SLN-ARM nodes was 19.6% (95% CI 14.4%-26.1%). The metastatic rate of ARM nodes was 16.9% (95% CI 14.2%-20.1%). The pooled incidence of lymphedema was 4.1% (95% CI 2.9–5.9%) for patients undergoing ARM procedure. Conclusions The ARM procedure was feasible during ALND. Nevertheless, it was restricted by low identification rate of ARM nodes during SLNB. ARM was beneficial for preventing lymphedema. However, this technique should be performed with caution given the possibility of crossover SLN-ARM nodes and metastatic ARM nodes. ARM appeared to be unsuitable for patients with clinically positive breast cancer due to oncological safety concern. PMID:26919589

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

NONE

This document contains the summaries of papers presented at the 1996 Atmospheric Radiation Measurement (ARM) Science Team meeting held at San Antonio, Texas. The history and status of the ARM program at the time of the meeting helps to put these papers in context. The basic themes have not changed. First, from its beginning, the Program has attempted to respond to the most critical scientific issues facing the US Global Change Research Program. Second, the Program has been strongly coupled to other agency and international programs. More specifically, the Program reflects an unprecedented collaboration among agencies of the federal researchmore » community, among the US Department of Energy`s (DOE) national laboratories, and between DOE`s research program and related international programs, such as Global Energy and Water Experiment (GEWEX) and the Tropical Ocean Global Atmosphere (TOGA) program. Next, ARM has always attempted to make the most judicious use of its resources by collaborating and leveraging existing assets and has managed to maintain an aggressive schedule despite budgets that have been much smaller than planned. Finally, the Program has attracted some of the very best scientific talent in the climate research community and has, as a result, been productive scientifically.« less

Using long-term ARM observations to evaluate Arctic mixed-phased cloud representation in the GISS ModelE GCM

NASA Astrophysics Data System (ADS)

Lamer, K.; Fridlind, A. M.; Luke, E. P.; Tselioudis, G.; Ackerman, A. S.; Kollias, P.; Clothiaux, E. E.

2016-12-01

The presence of supercooled liquid in clouds affects surface radiative and hydrological budgets, especially at high latitudes. Capturing these effects is crucial to properly quantifying climate sensitivity. Currently, a number of CGMs disagree on the distribution of cloud phase. Adding to the challenge is a general lack of observations on the continuum of clouds, from high to low-level and from warm to cold. In the current study, continuous observations from 2011 to 2014 are used to evaluate all clouds produced by the GISS ModelE GCM over the ARM North Slope of Alaska site. The International Satellite Cloud Climatology Project (ISCCP) Global Weather State (GWS) approach reveals that fair-weather (GWS 7, 32% occurrence rate), as well as mid-level storm related (GWS 5, 28%) and polar (GWS 4, 14%) clouds, dominate the large-scale cloud patterns at this high latitude site. At higher spatial and temporal resolutions, ground-based cloud radar observations reveal a majority of single layer cloud vertical structures (CVS). While clear sky and low-level clouds dominate (each with 30% occurrence rate) a fair amount of shallow ( 10%) to deep ( 5%) convection are observed. Cloud radar Doppler spectra are used along with depolarization lidar observations in a neural network approach to detect the presence, layering and inhomogeneity of supercooled liquid layers. Preliminary analyses indicate that most of the low-level clouds sampled contain one or more supercooled liquid layers. Furthermore, the relationship between CVS and the presence of supercooled liquid is established, as is the relationship between the presence of supercool liquid and precipitation susceptibility. Two approaches are explored to bridge the gap between large footprint GCM simulations and high-resolution ground-based observations. The first approach consists of comparing model output and ground-based observations that exhibit the same column CVS type (i.e. same cloud depth, height and layering). Alternatively, the second approach consists of comparing model output and ground-based observations that exhibit the same large-scale GWS type (i.e. same cloud top pressure and optical depth patterns) where ground-based observations are associated to large-scale GWS every 3 hours using the closest satellite overpass.

Motion and force control of multiple robotic manipulators

NASA Technical Reports Server (NTRS)

Wen, John T.; Kreutz-Delgado, Kenneth

1992-01-01

This paper addresses the motion and force control problem of multiple robot arms manipulating a cooperatively held object. A general control paradigm is introduced which decouples the motion and force control problems. For motion control, different control strategies are constructed based on the variables used as the control input in the controller design. There are three natural choices; acceleration of a generalized coordinate, arm tip force vectors, and the joint torques. The first two choices require full model information but produce simple models for the control design problem. The last choice results in a class of relatively model independent control laws by exploiting the Hamiltonian structure of the open loop system. The motion control only determines the joint torque to within a manifold, due to the multiple-arm kinematic constraint. To resolve the nonuniqueness of the joint torques, two methods are introduced. If the arm and object models are available, an optimization can be performed to best allocate the desired and effector control force to the joint actuators. The other possibility is to control the internal force about some set point. It is shown that effective force regulation can be achieved even if little model information is available.

Motor Costs and the Coordination of the Two Arms

PubMed Central

Shadmehr, Reza

2014-01-01

We have two arms, many muscles in each arm, and numerous neurons that contribute to their control. How does the brain assign responsibility to each of these potential actors? We considered a bimanual task in which people chose how much force to produce with each arm so that the sum would equal a target. We found that the dominant arm made a greater contribution, but only for specific directions. This was not because the dominant arm was stronger. Rather, it was less noisy. A cost that included unimanual noise and strength accounted for both direction- and handedness-dependent choices that young people made. To test whether there was a causal relationship between unimanual noise and bimanual control, we considered elderly people, whose unimanual noise is comparable in the two arms. We found that, in bimanual control, the elderly showed no preference for their dominant arm. We noninvasively stimulated the motor cortex to produce a change in unimanual strength and noise, and found a corresponding change in bimanual control. Using the noise measurements, we built a neuronal model. The model explained the anisotropic distribution of preferred directions of neurons in the monkey motor cortex and predicted that, in humans, there are changes in the number of these cortical neurons with handedness and aging. Therefore, we found that coordination can be explained by the noise and strength of each effector, where noise may be a reflection of the number of task-related neurons available for control of that effector in the motor cortex. PMID:24478362

FINAL REPORT (DE-FG02-97ER62338): Single-column modeling, GCM parameterizations, and ARM data

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

Richard C. J. Somerville

2009-02-27

Our overall goal is the development of new and improved parameterizations of cloud-radiation effects and related processes, using ARM data at all three ARM sites, and the implementation and testing of these parameterizations in global models. To test recently developed prognostic parameterizations based on detailed cloud microphysics, we have compared SCM (single-column model) output with ARM observations at the SGP, NSA and TWP sites. We focus on the predicted cloud amounts and on a suite of radiative quantities strongly dependent on clouds, such as downwelling surface shortwave radiation. Our results demonstrate the superiority of parameterizations based on comprehensive treatments ofmore » cloud microphysics and cloud-radiative interactions. At the SGP and NSA sites, the SCM results simulate the ARM measurements well and are demonstrably more realistic than typical parameterizations found in conventional operational forecasting models. At the TWP site, the model performance depends strongly on details of the scheme, and the results of our diagnostic tests suggest ways to develop improved parameterizations better suited to simulating cloud-radiation interactions in the tropics generally. These advances have made it possible to take the next step and build on this progress, by incorporating our parameterization schemes in state-of-the-art three-dimensional atmospheric models, and diagnosing and evaluating the results using independent data. Because the improved cloud-radiation results have been obtained largely via implementing detailed and physically comprehensive cloud microphysics, we anticipate that improved predictions of hydrologic cycle components, and hence of precipitation, may also be achievable.« less

Linear modeling of human hand-arm dynamics relevant to right-angle torque tool interaction.

PubMed

Ay, Haluk; Sommerich, Carolyn M; Luscher, Anthony F

2013-10-01

A new protocol was evaluated for identification of stiffness, mass, and damping parameters employing a linear model for human hand-arm dynamics relevant to right-angle torque tool use. Powered torque tools are widely used to tighten fasteners in manufacturing industries. While these tools increase accuracy and efficiency of tightening processes, operators are repetitively exposed to impulsive forces, posing risk of upper extremity musculoskeletal injury. A novel testing apparatus was developed that closely mimics biomechanical exposure in torque tool operation. Forty experienced torque tool operators were tested with the apparatus to determine model parameters and validate the protocol for physical capacity assessment. A second-order hand-arm model with parameters extracted in the time domain met model accuracy criterion of 5% for time-to-peak displacement error in 93% of trials (vs. 75% for frequency domain). Average time-to-peak handle displacement and relative peak handle force errors were 0.69 ms and 0.21%, respectively. Model parameters were significantly affected by gender and working posture. Protocol and numerical calculation procedures provide an alternative method for assessing mechanical parameters relevant to right-angle torque tool use. The protocol more closely resembles tool use, and calculation procedures demonstrate better performance of parameter extraction using time domain system identification methods versus frequency domain. Potential future applications include parameter identification for in situ torque tool operation and equipment development for human hand-arm dynamics simulation under impulsive forces that could be used for assessing torque tools based on factors relevant to operator health (handle dynamics and hand-arm reaction force).

Genomic evidence for role of inversion 3RP of Drosophila melanogaster in facilitating climate change adaptation.

PubMed

Rane, Rahul V; Rako, Lea; Kapun, Martin; Lee, Siu F; Hoffmann, Ary A

2015-05-01

Chromosomal inversion polymorphisms are common in animals and plants, and recent models suggest that alternative arrangements spread by capturing different combinations of alleles acting additively or epistatically to favour local adaptation. It is also thought that inversions typically maintain favoured combinations for a long time by suppressing recombination between alternative chromosomal arrangements. Here, we consider patterns of linkage disequilibrium and genetic divergence in an old inversion polymorphism in Drosophila melanogaster (In(3R)Payne) known to be associated with climate change adaptation and a recent invasion event into Australia. We extracted, karyotyped and sequenced whole chromosomes from two Australian populations, so that changes in the arrangement of the alleles between geographically separated tropical and temperate areas could be compared. Chromosome-wide linkage disequilibrium (LD) analysis revealed strong LD within the region spanned by In(3R)Payne. This genomic region also showed strong differentiation between the tropical and the temperate populations, but no differentiation between different karyotypes from the same population, after controlling for chromosomal arrangement. Patterns of differentiation across the chromosome arm and in gene ontologies were enhanced by the presence of the inversion. These data support the notion that inversions are strongly selected by bringing together combinations of genes, but it is still not clear if such combinations act additively or epistatically. Our data suggest that climatic adaptation through inversions can be dynamic, reflecting changes in the relative abundance of different forms of an inversion and ongoing evolution of allelic content within an inversion. © 2015 John Wiley & Sons Ltd.

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

Sun, Yan; Xu, Ye; Yang, Ji

Combining H I data from the Canadian Galactic Plane Survey and CO data from the Milky Way Imaging Scroll Painting project, we have identified a new segment of a spiral arm between Galactocentric radii of 15 and 19 kpc that apparently lies beyond the Outer Arm in the second Galactic quadrant. Over most of its length, the arm is 400-600 pc thick in z. The new arm appears to be the extension of the distant arm recently discovered by Dame and Thaddeus as well as the Scutum-Centaurus Arm into the outer second quadrant. Our current survey identified a total of 72more » molecular clouds with masses on the order of 10{sup 2}-10{sup 4} M {sub ☉} that probably lie in the new arm. When all of the available data from the CO molecular clouds are fit, the best-fitting spiral model gives a pitch angle of 9.°3 ± 0.°7.« less

The effect of operational stressors on ibuprofen pharmacokinetics.

PubMed

Boscarino, Cathy; Edginton, Andrea N; Peng, Henry; Riggs, K Wayne; Szeitz, András; Cheung, Bob

2013-01-01

To determine whether two of the major operational stressors associated with military missions in Afghanistan: dry heat and long durations of soldier patrol (SP), alter the pharmacokinetics of ibuprofen. Thirteen healthy and physically fit participants (19-32 years) were randomized to a four-arm crossover study, as follows: Arm 4 consisted of a simulated 2.5 h SP on a treadmill set at 4.5 km/h, 2% incline (15-min walk/5-min rest cycle) in a climatic chamber set to 42°C, 9% relative humidity. Arm 3 was similar to arm 4 but at room temperature, and arms 1 and 2 were sham SP to 3 and 4, respectively. For the final 2.5 h, participants remained in a semi-supine position. Each participant orally administered one 400-mg Advil Liqui-Gel® capsule. Blood samples were drawn over time and analyzed for (R)-ibuprofen and (S)-plasma ibuprofen concentrations using UPLC/MS/MS. Concentration-time data were analyzed by compartmental methods. Exercise significantly decreased the t(1/2abs) (h) of (S)-ibuprofen (0.26 to 0.17; p = 0.015) and T(max) (h) for both (R)-ibuprofen (0.97 to 0.73; p = 0.008) and (S)-ibuprofen (1.13 to 0.84; p = 0.005). Values for t(lag) (h) also decreased with exercise for both (R)-ibuprofen (0.38 to 0.22; p = 0.005), and (S)-ibuprofen (0.39 to 0.23; p = 0.001). Exercise stress had a significant impact on the absorption profile of (R)- and (S)-ibuprofen. Excessive self-administration rate and dose may not be due to the military operational stressors of heat and soldier presence patrol.

Armed conflict: a model for understanding and intervention.

PubMed

2013-01-01

Acts of deadly violence give rise to powerful emotions and trigger pre-programmed responses that often cause affected persons, including leaders, media, armed forces, and the general public, to act in ways that aggravate the situation and feed into cycles of violence. In this article, a model of the cycle of violence is presented that facilitates logical analysis and response. Starting from an act of deadly violence this model traces a series of interacting factors that can lead to armed conflict. These include distortions of perception and response that impact the public and their leaders. Negative codes, prejudices, and myths feed fear and grief which may then escalate and lead to violent retaliation thereby triggering a similar response. Those professionals who care for bereaved individuals and families are familiar with these emotions and responses and are well qualified to analyze, explain, and support people affected by armed conflict. We suggest that they could also play educational and other important roles in reducing escalation and breaking the cycle of violence.

Evaluation of NCAR CAM5 Simulated Marine Boundary Layer Cloud Properties Using a Combination of Satellite and Surface Observations

NASA Astrophysics Data System (ADS)

Zhang, Z.; Song, H.; Wang, M.; Ghan, S. J.; Dong, X.

2016-12-01

he main objective of this study is to systematically evaluate the MBL cloud properties simulated in CAM5 family models using a combination of satellite-based CloudSat/MODIS observations and ground-based observations from the ARM Azores site, with a special focus on MBL cloud microphysics and warm rain process. First, we will present a global evaluation based on satellite observations and retrievals. We will compare global cloud properties (e.g., cloud fraction, cloud vertical structure, cloud CER, COT, and LWP, as well as drizzle frequency and intensity diagnosed using the CAM5-COSP instrumental simulators) simulated in the CAM5 models with the collocated CloudSat and MODIS observations. We will also present some preliminary results from a regional evaluation based mainly on ground observations from ARM Azores site. We will compare MBL cloud properties simulated in CAM5 models over the ARM Azores site with collocated satellite (MODIS and CloudSat) and ground-based observations from the ARM site.

Design of a biomimetic robotic octopus arm.

PubMed

Laschi, C; Mazzolai, B; Mattoli, V; Cianchetti, M; Dario, P

2009-03-01

This paper reports the rationale and design of a robotic arm, as inspired by an octopus arm. The octopus arm shows peculiar features, such as the ability to bend in all directions, to produce fast elongations, and to vary its stiffness. The octopus achieves these unique motor skills, thanks to its peculiar muscular structure, named muscular hydrostat. Different muscles arranged on orthogonal planes generate an antagonistic action on each other in the muscular hydrostat, which does not change its volume during muscle contractions, and allow bending and elongation of the arm and stiffness variation. By drawing inspiration from natural skills of octopus, and by analysing the geometry and mechanics of the muscular structure of its arm, we propose the design of a robot arm consisting of an artificial muscular hydrostat structure, which is completely soft and compliant, but also able to stiffen. In this paper, we discuss the design criteria of the robotic arm and how this design and the special arrangement of its muscular structure may bring the building of a robotic arm into being, by showing the results obtained by mathematical models and prototypical mock-ups.

Decoupling Identification for Serial Two-Link Two-Inertia System

NASA Astrophysics Data System (ADS)

Oaki, Junji; Adachi, Shuichi

The purpose of our study is to develop a precise model by applying the technique of system identification for the model-based control of a nonlinear robot arm, under taking joint-elasticity into consideration. We previously proposed a systematic identification method, called “decoupling identification,” for a “SCARA-type” planar two-link robot arm with elastic joints caused by the Harmonic-drive® reduction gears. The proposed method serves as an extension of the conventional rigid-joint-model-based identification. The robot arm is treated as a serial two-link two-inertia system with nonlinearity. The decoupling identification method using link-accelerometer signals enables the serial two-link two-inertia system to be divided into two linear one-link two-inertia systems. The MATLAB®'s commands for state-space model estimation are utilized in the proposed method. Physical parameters such as motor inertias, link inertias, joint-friction coefficients, and joint-spring coefficients are estimated through the identified one-link two-inertia systems using a gray-box approach. This paper describes accuracy evaluations using the two-link arm for the decoupling identification method under introducing closed-loop-controlled elements and varying amplitude-setup of identification-input. Experimental results show that the identification method also works with closed-loop-controlled elements. Therefore, the identification method is applicable to a “PUMA-type” vertical robot arm under gravity.

The influence of nevirapine and efavirenz-based anti-retroviral therapy on the pharmacokinetics of lumefantrine and anti-malarial dose recommendation in HIV-malaria co-treatment.

PubMed

Maganda, Betty A; Ngaimisi, Eliford; Kamuhabwa, Appolinary A R; Aklillu, Eleni; Minzi, Omary M S

2015-04-25

HIV-malaria co-infected patients in most parts of sub-Saharan Africa are treated with both artemether-lumefantrine (AL) and efavirenz (EFV) or nevirapine (NVP)-based antiretroviral therapy (ART). EFV, NVP, artemether and lumefantrine are substrates, inhibitors or inducers of CYP3A4 and CYP2B6, creating a potential for drug-drug interactions. The effect of EFV and/or NVP on lumefantrine pharmacokinetic profile among HIV-malaria co-infected patients on ART and treated with AL was investigated. Optimal lumefantrine dosage regimen for patients on EFV-based ART was determined by population pharmacokinetics and simulation. This was a non-randomized, open label, parallel, prospective cohort study in which 128, 66 and 75 HIV-malaria co-infected patients on NVP-based ART (NVP-arm), EFV-based ART (EFV-arm) and ART naïve (control-am) were enrolled, respectively. Patients were treated with AL and contributed sparse venous plasma samples. Pharmacokinetic analysis of lumefantrine was done using non-linear mixed effect modelling. Of the evaluated models, a two-compartment pharmacokinetic model with first order absorption and lag-time described well lumefantrine plasma concentrations time profile. Patients in the EFV-arm but not in the NVP-arm had significantly lower lumefantrine bioavailability compared to that in the control-arm. Equally, 32% of patients in the EFV-arm had day-7 lumefantrine plasma concentrations below 280 ng/ml compared to only 4% in the control-arm and 3% in the NVP-arm. Upon post hoc simulation of lumefantrine exposure, patients in the EFV-arm had lower exposure (median (IQR)) compared to that in the control-arm; AUC0-inf; was 303,130 (211,080-431,962) versus 784,830 (547,405-1,116,250); day-7 lumefantrine plasma concentrations was: 335.5 (215.8-519.5) versus 858.7 (562.3-1,333.8), respectively. The predictive model through simulation of lumefantrine exposure at different dosage regimen scenarios for patients on EFV-based ART, suggest that AL taken twice daily for five days using the current dose could improve lumefantrine exposure and consequently malaria treatment outcomes. Co-treatment of AL with EFV-based ART but not NVP-based ART significantly reduces lumefantrine bioavailability and consequently total exposure. To ensure adequate lumefantrine exposure and malaria treatment success in HIV-malaria co-infected patients on EFV-based ART, an extension of the duration of AL treatment to five days using the current dose is proposed.

An improved Monte-Carlo model of the Varian EPID separating support arm and rear-housing backscatter

NASA Astrophysics Data System (ADS)

Monville, M. E.; Kuncic, Z.; Greer, P. B.

2014-03-01

Previous investigators of EPID dosimetric properties have ascribed the backscatter, that contaminates dosimetric EPID images, to its supporting arm. Accordingly, Monte-Carlo (MC) EPID models have approximated the backscatter signal from the layers under the detector and the robotic support arm using either uniform or non-uniform solid water slabs, or through convolutions with back-scatter kernels. The aim of this work is to improve the existent MC models by measuring and modelling the separate backscatter contributions of the robotic arm and the rear plastic housing of the EPID. The EPID plastic housing is non-uniform with a 11.9 cm wide indented section that runs across the cross-plane direction in the superior half of the EPID which is 1.75 cm closer to the EPID sensitive layer than the rest of the housing. The thickness of the plastic housing is 0.5 cm. Experiments were performed with and without the housing present by removing all components of the EPID from the housing. The robotic support arm was not present for these measurements. A MC model of the linear accelerator and the EPID was modified to include the rear-housing indentation and results compared to the measurement. The rear housing was found to contribute a maximum of 3% additional signal. The rear housing contribution to the image is non-uniform in the in-plane direction with 2% asymmetry across the central 20 cm of an image irradiating the entire detector. The MC model was able to reproduce this non-uniform contribution. The EPID rear housing contributes a non-uniform backscatter component to the EPID image, which has not been previously characterized. This has been incorporated into an improved MC model of the EPID.

Shortwave Hyperspectral Observations During MAGIC Final Campaign Summary

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

McBride, P. J.; Marshak, A.; Yang, W.

The Marine ARM GPCI1 Investigation of Clouds (MAGIC) field campaign was initiated to improve our understanding of low-level marine clouds that have a significant influence on the Earth’s climate. The campaign was conducted using an ARM mobile facility deployed on a commercial ship traveling between Honolulu, Hawaii, and Los Angeles, California, from October 2012 to September 2013. The solar spectral flux radiometer (SSFR) was deployed on July 6, 2013, through the end of the campaign. The SSFR was calibrated and installed by Warren Gore of NASA Ames Research Center, and the data is and will be analyzed by Drs. Alexandermore » Marshak and Weidong Yang of NASA Goddard Space Flight Center, Dr. Samuel LeBlanc of NASA Ames Research Center, Dr. Sebastian Schmidt of the University of Colorado-Boulder, and Dr. Patrick McBride of Atmospheric & Space Technology Research Associates in Boulder, Colorado.« less

Meat and masculinity in the Norwegian Armed Forces.

PubMed

Kildal, Charlotte Lilleby; Syse, Karen Lykke

2017-05-01

In 2013, the Norwegian Armed Forces decided to introduce a meat reduction scheme in its military mess halls, for both health reasons and environmental concerns. This article explores Norwegian soldiers' reactions to the introduction of Meat free Monday, and their attitudes towards reducing meat consumption. As of yet, Meat free Monday has not been implemented due to both structural and contextual challenges. We explore both the process and potential of the Norwegian military's Meat free Monday initiative to promote sustainable and climate friendly diets. We found significant barriers preventing the military from implementing Meat free Monday. The main reason behind the resistance to reduce meat consumption among Norwegian soldiers was meat's associations with protein, masculinity and comfort. Our results underline the importance of acknowledging the social and cultural role of food. The study is qualitative and uses focus group interviews as its main methodology. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Development of a Portable Modular Component Building System for the Armed Forces

DTIC Science & Technology

1985-11-08

environment and provide optimum thermal comfort and energy performance throughout a wide climatic range. Finally, such a system would provide optimum user...I I I I I l i 56. ind thermal comfort . The low humidity of the atmosphere allows temperatures to fal. deeply at night so buildings constructed of hig...site topographies. Extensive support equipment is also required for their transport, erection and sustained thermal comfort for the occupants. Off the

A Cultural Resource Inventory of 13 Proposed Waterfowl Ponds and a Sample of the Prairie Dog Arm, Harlan County Lake, Nebraska

DTIC Science & Technology

1988-01-01

information derived from surrounding areas, this cultural period was characterized by intensive hunting of Pleistocene megafauna augmented by some gathering...migratory patterns of the Pleistocene megafauna brought about by the Altithermal climatic shifts. Archaic period sites contain nebulous house floors...surpassed the erosional and gradient stages. In the project area streams with mature beds have low gradients and are slow moving through wide meander

Climate Science - getting the world to understand, and to care

NASA Astrophysics Data System (ADS)

Jasmin, T.; Ackerman, S. A.; Whittaker, T. M.

2012-12-01

Effectively teaching and conveying climate science has become one of Earth Science's greatest challenges. Existing barriers are many and varied, from political, ideological, and religious, to purely economic. Additionally, studies show the general public at present has a surprising number of basic misconceptions regarding the Earth system, and Earth-Sun relationships. Addressing these misconceptions is the first hurdle to overcome for properly teaching climate science. This talk will discuss ways to address the various barriers. Strategies are being employed to arm teachers with new tools leveraging the move to online, interactive learning. Content can be tailored particular audiences. For any individual, learning will be most effective if there is an understood significance, the information is presented clearly and at an appropriate education level, and when possible some personal relevance can be inferred. People need a reason to care. Examples and approaches for several common education scenarios will be given. A simple "Climate Change 101" outline will be given, a blueprint that could be used to educate most of the general public. Freely available online resources to address Earth System misconceptions will be referenced. Finally, a case will be made that a dramatic improvement in climate literacy worldwide may be the only viable means to successfully tackling global warming.

Stereotypical reaching movements of the octopus involve both bend propagation and arm elongation.

PubMed

Hanassy, S; Botvinnik, A; Flash, T; Hochner, B

2015-05-13

The bend propagation involved in the stereotypical reaching movement of the octopus arm has been extensively studied. While these studies have analyzed the kinematics of bend propagation along the arm during its extension, possible length changes have been ignored. Here, the elongation profiles of the reaching movements of Octopus vulgaris were assessed using three-dimensional reconstructions. The analysis revealed that, in addition to bend propagation, arm extension movements involve elongation of the proximal part of the arm, i.e., the section from the base of the arm to the propagating bend. The elongations are quite substantial and highly variable, ranging from an average strain along the arm of -0.12 (i.e. shortening) up to 1.8 at the end of the movement (0.57 ± 0.41, n = 64 movements, four animals). Less variability was discovered in an additional set of experiments on reaching movements (0.64 ± 0.28, n = 30 movements, two animals), where target and octopus positions were kept more stationary. Visual observation and subsequent kinematic analysis suggest that the reaching movements can be broadly segregated into two groups. The first group involves bend propagation beginning at the base of the arm and propagating towards the arm tip. In the second, the bend is formed or present more distally and reaching is achieved mainly by elongation and straightening of the segment proximal to the bend. Only in the second type of movements is elongation significantly positively correlated with the distance of the bend from the target. We suggest that reaching towards a target is generated by a combination of both propagation of a bend along the arm and arm elongation. These two motor primitives may be combined to create a broad spectrum of reaching movements. The dynamical model, which recapitulates the biomechanics of the octopus muscular hydrostatic arm, suggests that achieving the observed elongation requires an extremely low ratio of longitudinal to transverse muscle force (<0.0016 for an average strain along the arm of around 0.5). This was not observed and moreover such extremely low value does not seem to be physiologically possible. Hence the assumptions made in applying the dynamic model to behaviors such as static arm stiffening that leads to arm extension through bend propagation and the patterns of activation used to simulate such behaviors should be modified to account for movements combining bend propagation and arm elongation.

Dynamic simulation of perturbation responses in a closed-loop virtual arm model.

PubMed

Du, Yu-Fan; He, Xin; Lan, Ning

2010-01-01

A closed-loop virtual arm (VA) model has been developed in SIMULINK environment by adding spinal reflex circuits and propriospinal neural networks to the open-loop VA model developed in early study [1]. An improved virtual muscle model (VM4.0) is used to speed up simulation and to generate more precise recruitment of muscle force at low levels of muscle activation. Time delays in the reflex loops are determined by their synaptic connections and afferent transmission back to the spinal cord. Reflex gains are properly selected so that closed-loop responses are stable. With the closed-loop VA model, we are developing an approach to evaluate system behaviors by dynamic simulation of perturbation responses. Joint stiffness is calculated based on simulated perturbation responses by a least-squares algorithm in MATLAB. This method of dynamic simulation will be essential for further evaluation of feedforward and reflex control of arm movement and position.

A human body model for efficient numerical characterization of UWB signal propagation in wireless body area networks.

PubMed

Lim, Hooi Been; Baumann, Dirk; Li, Er-Ping

2011-03-01

Wireless body area network (WBAN) is a new enabling system with promising applications in areas such as remote health monitoring and interpersonal communication. Reliable and optimum design of a WBAN system relies on a good understanding and in-depth studies of the wave propagation around a human body. However, the human body is a very complex structure and is computationally demanding to model. This paper aims to investigate the effects of the numerical model's structure complexity and feature details on the simulation results. Depending on the application, a simplified numerical model that meets desired simulation accuracy can be employed for efficient simulations. Measurements of ultra wideband (UWB) signal propagation along a human arm are performed and compared to the simulation results obtained with numerical arm models of different complexity levels. The influence of the arm shape and size, as well as tissue composition and complexity is investigated.

Multi-scale Modeling of Arctic Clouds

NASA Astrophysics Data System (ADS)

Hillman, B. R.; Roesler, E. L.; Dexheimer, D.

2017-12-01

The presence and properties of clouds are critically important to the radiative budget in the Arctic, but clouds are notoriously difficult to represent in global climate models (GCMs). The challenge stems partly from a disconnect in the scales at which these models are formulated and the scale of the physical processes important to the formation of clouds (e.g., convection and turbulence). Because of this, these processes are parameterized in large-scale models. Over the past decades, new approaches have been explored in which a cloud system resolving model (CSRM), or in the extreme a large eddy simulation (LES), is embedded into each gridcell of a traditional GCM to replace the cloud and convective parameterizations to explicitly simulate more of these important processes. This approach is attractive in that it allows for more explicit simulation of small-scale processes while also allowing for interaction between the small and large-scale processes. The goal of this study is to quantify the performance of this framework in simulating Arctic clouds relative to a traditional global model, and to explore the limitations of such a framework using coordinated high-resolution (eddy-resolving) simulations. Simulations from the global model are compared with satellite retrievals of cloud fraction partioned by cloud phase from CALIPSO, and limited-area LES simulations are compared with ground-based and tethered-balloon measurements from the ARM Barrow and Oliktok Point measurement facilities.

Robust coordinated control of a dual-arm space robot

NASA Astrophysics Data System (ADS)

Shi, Lingling; Kayastha, Sharmila; Katupitiya, Jay

2017-09-01

Dual-arm space robots are more capable of implementing complex space tasks compared with single arm space robots. However, the dynamic coupling between the arms and the base will have a serious impact on the spacecraft attitude and the hand motion of each arm. Instead of considering one arm as the mission arm and the other as the balance arm, in this work two arms of the space robot perform as mission arms aimed at accomplishing secure capture of a floating target. The paper investigates coordinated control of the base's attitude and the arms' motion in the task space in the presence of system uncertainties. Two types of controllers, i.e. a Sliding Mode Controller (SMC) and a nonlinear Model Predictive Controller (MPC) are verified and compared with a conventional Computed-Torque Controller (CTC) through numerical simulations in terms of control accuracy and system robustness. Both controllers eliminate the need to linearly parameterize the dynamic equations. The MPC has been shown to achieve performance with higher accuracy than CTC and SMC in the absence of system uncertainties under the condition that they consume comparable energy. When the system uncertainties are included, SMC and CTC present advantageous robustness than MPC. Specifically, in a case where system inertia increases, SMC delivers higher accuracy than CTC and costs the least amount of energy.

Control strategy for a dual-arm maneuverable space robot

NASA Technical Reports Server (NTRS)

Wang, P. K. C.

1987-01-01

A simple strategy for the attitude control and arm coordination of a maneuverable space robot with dual arms is proposed. The basic task for the robot consists of the placement of marked rigid solid objects with specified pairs of gripping points and a specified direction of approach for gripping. The strategy consists of three phases each of which involves only elementary rotational and translational collision-free maneuvers of the robot body. Control laws for these elementary maneuvers are derived by using a body-referenced dynamic model of the dual-arm robot.

Consequences of impact on arm (elbow and shoulder joints) caused by ball hitting, theoretical analysis

NASA Astrophysics Data System (ADS)

Negrea, Adina; Busuioceanu, Ioana Iuliana

2018-02-01

Present paper estimates the mechanics of the impact of a ball and a hand-arm, during the sports training using a classical model for the hand-arm system, avoiding the contribution of the coefficient of restitution. The results of this investigation are focused on the equations needed to find out theimpact reactions in elbow and shoulder joints, for different anthropometric data. Also, the computing of the position of mass centers and the moments of inertia for each constitutive part of hand-arm system is made.

Thermodynamic Controls on Deep Convection in the Tropics: Observations and Applications to Modeling

NASA Astrophysics Data System (ADS)

Schiro, Kathleen Anne

Constraining precipitation processes in climate models with observations is crucial to accurately simulating current climate and reducing uncertainties in future projections. This work presents robust relationships between tropical deep convection, column-integrated water vapor (CWV), and other thermodynamic quantities analyzed with data from the DOE Atmospheric Radiation Measurement (ARM) Mobile Facility in Manacapuru, Brazil as part of the GOAmazon campaign and are directly compared to such relationships at DOE ARM sites in the tropical western Pacific. A robust relationship between CWV and precipitation, as explained by variability in lower tropospheric humidity, exists just as strongly in a tropical continental region as it does in a tropical oceanic region. Given sufficient mixing in the lower troposphere, higher CWV generally results in greater plume buoyancies through a deep convective layer. Although sensitivity of convection to other controls is suggested, such as microphysical processes and dynamical lifting mechanisms, the increase in buoyancy with CWV is consistent with the sharp increase in precipitation observed. Entraining plume buoyancy calculations confirm that CWV is a good proxy for the conditional instability of the environment, yet differences in convective onset as a function of CWV exist over land and ocean, as well as seasonally and diurnally over land. This is largely due to variability in the contribution of lower tropospheric humidity to the total column moisture. Over land, the relationship between deep convection and lower free tropospheric moisture is robust across all seasons and times of day, whereas the relation to boundary layer moisture is robust for the daytime only. Using S-Band radar, these transition statistics are examined separately for unorganized and mesoscale-organized convection, which exhibit sharp increases in probability of occurrence with increasing moisture throughout the column, particularly in the lower free troposphere. An observational basis for an integrated buoyancy measure from a single plume buoyancy formulation that provides a strong relation to precipitation can be useful for constraining convective parameterizations. A mixing scheme corresponding to deep inflow of environmental air into a plume that grows with height provides a weighting of boundary layer and free tropospheric air that yields buoyancies consistent with the observed onset of deep convection across seasons and times of day, across land and ocean sites, and for all convection types. This provides a substantial improvement relative to more traditional constant mixing assumptions, and a dramatic improvement relative to no mixing. Furthermore, it provides relationships that are as strong or stronger for mesoscale-organized convection as for unorganized convection. Downdrafts and their associated parameters are poorly constrained in models, as physical and microphysical processes of leading order importance are difficult to observe with sufficient frequency for development of robust statistics. Downdrafts and cold pool characteristics for mesoscale convective systems (MCSs) and isolated, unorganized deep precipitating convection in the Amazon are composited and both exhibit similar signatures in wind speed, surface fluxes, surface equivalent potential temperature (theta e) and precipitation. For both MCSs and unorganized convection, downdrafts associated with the strongest modifications to surface thermodynamics have increasing probability of occurrence with decreasing height through the lowest 4 km and show similar mean downdraft magnitudes with height. If theta e is approximately conserved following descent, a large fraction of the air reaching the surface likely originates at altitudes in the lowest 2 km. Mixing computations suggest that, on average, air originating at heights greater than 3 km would require substantial mixing, particularly in the case of isolated cells, to match the observed cold pool thetae . Statistics from two years of surface meteorological data at the GOAmazon site and 15 years of data at the DOE ARM site on Manus Island in the tropical western Pacific show that Deltathetae conditioned on precipitation levels off with increasing precipitation rate, bounded by the maximum difference between surface thetae and its minimum in the profile aloft. Robustness of these statistics observed across scales and regions suggests their potential use as model diagnostic tools for the improvement of downdraft parameterizations in climate models.

Armed Conflict: A Model for Understanding and Intervention

ERIC Educational Resources Information Center

Death Studies, 2013

2013-01-01

Acts of deadly violence give rise to powerful emotions and trigger pre-programmed responses that often cause affected persons, including leaders, media, armed forces, and the general public, to act in ways that aggravate the situation and feed into cycles of violence. In this article, a model of the cycle of violence is presented that facilitates…

Experimental verification of arm-locking for LISA using electronic phase delay [rapid communication

NASA Astrophysics Data System (ADS)

Thorpe, J. I.; Mueller, G.

2005-07-01

We present results of an electronic model of arm-locking, a proposed technique for reducing the laser phase noise in the laser interferometer space antenna (LISA). The model is based on a delay of 500 ms, achieved using the electronic phase delay (EPD) method. The observed behavior is consistent with predictions.

Cardio-Respiratory Responses to Maximal Work During Arm and Bicycle Ergometry.

ERIC Educational Resources Information Center

Israel, Richard G.; Hardison, George T.

This study compared cardio-respiratory responses during maximal arm work using a Monarch Model 880 Rehab Trainer to cardio-respiratory responses during maximal leg work on a Monarch Model 850 Bicycle Ergometer. Subjects for the investigation were 17 male university students ranging from 18 to 28 years of age. The specific variables compared…

How sensitive is the deltoid moment arm to humeral offset changes with reverse total shoulder arthroplasty?

PubMed

Walker, David R; Kinney, Allison L; Wright, Thomas W; Banks, Scott A

2016-06-01

Reverse total shoulder arthroplasty commonly treats cuff-deficient or osteoarthritic shoulders not amenable to rotator cuff repair. This study investigates deltoid moment arm sensitivity to variations in the joint center and humeral offset of 3 representative reverse total shoulder arthroplasty subjects. We hypothesized that a superior joint implant placement may exist, indicated by muscle moment arms, compared with the current actual surgical implant configuration. Moment arms for the anterior, lateral, and posterior aspects of the deltoid muscle were determined for 1521 perturbations of the humeral offset location away from the surgical placement in a subject-specific musculoskeletal model with motion defined by subject-specific in vivo abduction kinematics. The humeral offset was varied from its surgical position ±4 mm in the anterior/posterior direction, ±12 mm in the medial/lateral direction, and -10 to 14 mm in the superior/inferior direction. The anterior deltoid moment arm varied in humeral offset and center of rotation up to 20 mm, primarily in the medial/lateral and superior/inferior directions. The lateral deltoid moment arm varied in humeral offset up to 20 mm, primarily in the medial/lateral and anterior/posterior directions. The posterior deltoid moment arm varied up to 15 mm, primarily in early abduction, and was most sensitive to humeral offset changes in the superior/inferior direction. High variations in muscle moment arms were found for all 3 deltoid components, presenting an opportunity to dramatically change the deltoid moment arms through surgical placement of the reverse shoulder components and by varying the overall offset of the humerus. Basic Science Study; Computer Modeling. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Optimal output fast feedback in two-time scale control of flexible arms

NASA Technical Reports Server (NTRS)

Siciliano, B.; Calise, A. J.; Jonnalagadda, V. R. P.

1986-01-01

Control of lightweight flexible arms moving along predefined paths can be successfully synthesized on the basis of a two-time scale approach. A model following control can be designed for the reduced order slow subsystem. The fast subsystem is a linear system in which the slow variables act as parameters. The flexible fast variables which model the deflections of the arm along the trajectory can be sensed through strain gage measurements. For full state feedback design the derivatives of the deflections need to be estimated. The main contribution of this work is the design of an output feedback controller which includes a fixed order dynamic compensator, based on a recent convergent numerical algorithm for calculating LQ optimal gains. The design procedure is tested by means of simulation results for the one link flexible arm prototype in the laboratory.

From reaching to reach-to-grasp: the arm posture difference and its implications on human motion control strategy.

PubMed

Li, Zhi; Milutinović, Dejan; Rosen, Jacob

2017-05-01

Reach-to-grasp arm postures differ from those in pure reaching because they are affected by grasp position/orientation, rather than simple transport to a position during a reaching motion. This paper investigates this difference via an analysis of experimental  data collected on reaching and reach-to-grasp motions. A seven-degree-of-freedom (DOFs) kinematic arm model with the swivel angle is used for the motion analysis. Compared to a widely used anatomical arm model, this model distinguishes clearly the four grasping-relevant DOFs (GR-DOFs) that are affected by positions and orientations of the objects to be grasped. These four GR-DOFs include the swivel angle that measures the elbow rotation about the shoulder-wrist axis, and three wrist joint angles. For each GR-DOF, we quantify position vs orientation task-relevance bias that measures how much the DOF is affected by the grasping position vs orientation. The swivel angle and forearm supination have similar bias, and the analysis of their motion suggests two hypotheses regarding the synergistic coordination of the macro- and micro-structures of the human arm (1) DOFs with similar task-relevance are synergistically coordinated; and (2) such synergy breaks when a task-relevant DOF is close to its joint limit without necessarily reaching the limit. This study provides a motion analysis method to reduce the control complexity for reach-to-grasp tasks, and suggests using dynamic coupling to coordinate the hand and arm of upper-limb exoskeletons.

Hydroponic system design with real time OS based on ARM Cortex-M microcontroller

NASA Astrophysics Data System (ADS)

Atmadja, Wiedjaja; Liawatimena, Suryadiputra; Lukas, Jonathan; Nata, Eka Putra Leo; Alexander, Ivan

2017-12-01

Hydroponic is the process of growing plants without soil, plant root flooded or moist with nutrient-rich solutions in inert material. Hydroponics has become a reality for greenhouse growers in virtually all climates. Large hydroponic installations exist throughout the world for growing flowers, vegetables and some short period fruit like tomato and cucumber. In soilless culture, we must maintain stable pH and conductivity level of nutrient solution to make plant grow well, large variation of pH of certain time will poisoned plant. This paper describes development complete automation hydroponic system, from maintaining stable nutrient composition (conductivity and pH), grow light, and monitor plant environment such as CO2, temperature and humidity. The heart of our automation is ARM Cortex-M4 from ST Microelectronic running ARM mbed OS, the official Real Time Operating System (RTOS) for ARM Cortex-M microcontroller. Using RTOS gives us flexibility to have multithreaded process. Results show that system capable to control desired concentration level with variation of less than 3%, pH sensor show good accuracy 5.83% from pH value 3.23-10. Growing light intensity measurement show result 105 μmol/m2/s therefore we need turn on the light at least 17 hours/day to fulfil plant light requirement. RTOS give good performance with latency and jitter less than 15 us, system overall show good performance and accuracy for automating hydroponic plant in vegetative phase of growth.

Modelling tendon excursions and moment arms of the finger flexors: anatomic fidelity versus function.

PubMed

Kociolek, Aaron M; Keir, Peter J

2011-07-07

A detailed musculoskeletal model of the human hand is needed to investigate the pathomechanics of tendon disorders and carpal tunnel syndrome. The purpose of this study was to develop a biomechanical model with realistic flexor tendon excursions and moment arms. An existing upper extremity model served as a starting point, which included programmed movement of the index finger. Movement capabilities were added for the other fingers. Metacarpophalangeal articulations were modelled as universal joints to simulate flexion/extension and abduction/adduction while interphalangeal articulations used hinges to represent flexion. Flexor tendon paths were modelled using two approaches. The first method constrained tendons with control points, representing annular pulleys. The second technique used wrap objects at the joints as tendon constraints. Both control point and joint wrap models were iteratively adjusted to coincide with tendon excursions and moment arms from a anthropometric regression model using inputs for a 50th percentile male. Tendon excursions from the joint wrap method best matched the regression model even though anatomic features of the tendon paths were not preserved (absolute differences: mean<0.33 mm, peak<0.74 mm). The joint wrap model also produced similar moment arms to the regression (absolute differences: mean<0.63 mm, peak<1.58 mm). When a scaling algorithm was used to test anthropometrics, the scaled joint wrap models better matched the regression than the scaled control point models. Detailed patient-specific anatomical data will improve model outcomes for clinical use; however, population studies may benefit from simplified geometry, especially with anthropometric scaling. Copyright © 2011 Elsevier Ltd. All rights reserved.

A Large Complement of the Predicted Arabidopsis ARM Repeat Proteins Are Members of the U-Box E3 Ubiquitin Ligase Family1[w

PubMed Central

Mudgil, Yashwanti; Shiu, Shin-Han; Stone, Sophia L.; Salt, Jennifer N.; Goring, Daphne R.

2004-01-01

The Arabidopsis genome was searched to identify predicted proteins containing armadillo (ARM) repeats, a motif known to mediate protein-protein interactions in a number of different animal proteins. Using domain database predictions and models generated in this study, 108 Arabidopsis proteins were identified that contained a minimum of two ARM repeats with the majority of proteins containing four to eight ARM repeats. Clustering analysis showed that the 108 predicted Arabidopsis ARM repeat proteins could be divided into multiple groups with wide differences in their domain compositions and organizations. Interestingly, 41 of the 108 Arabidopsis ARM repeat proteins contained a U-box, a motif present in a family of E3 ligases, and these proteins represented the largest class of Arabidopsis ARM repeat proteins. In 14 of these U-box/ARM repeat proteins, there was also a novel conserved domain identified in the N-terminal region. Based on the phylogenetic tree, representative U-box/ARM repeat proteins were selected for further study. RNA-blot analyses revealed that these U-box/ARM proteins are expressed in a variety of tissues in Arabidopsis. In addition, the selected U-box/ARM proteins were found to be functional E3 ubiquitin ligases. Thus, these U-box/ARM proteins represent a new family of E3 ligases in Arabidopsis. PMID:14657406

A large complement of the predicted Arabidopsis ARM repeat proteins are members of the U-box E3 ubiquitin ligase family.

PubMed

Mudgil, Yashwanti; Shiu, Shin-Han; Stone, Sophia L; Salt, Jennifer N; Goring, Daphne R

2004-01-01

The Arabidopsis genome was searched to identify predicted proteins containing armadillo (ARM) repeats, a motif known to mediate protein-protein interactions in a number of different animal proteins. Using domain database predictions and models generated in this study, 108 Arabidopsis proteins were identified that contained a minimum of two ARM repeats with the majority of proteins containing four to eight ARM repeats. Clustering analysis showed that the 108 predicted Arabidopsis ARM repeat proteins could be divided into multiple groups with wide differences in their domain compositions and organizations. Interestingly, 41 of the 108 Arabidopsis ARM repeat proteins contained a U-box, a motif present in a family of E3 ligases, and these proteins represented the largest class of Arabidopsis ARM repeat proteins. In 14 of these U-box/ARM repeat proteins, there was also a novel conserved domain identified in the N-terminal region. Based on the phylogenetic tree, representative U-box/ARM repeat proteins were selected for further study. RNA-blot analyses revealed that these U-box/ARM proteins are expressed in a variety of tissues in Arabidopsis. In addition, the selected U-box/ARM proteins were found to be functional E3 ubiquitin ligases. Thus, these U-box/ARM proteins represent a new family of E3 ligases in Arabidopsis.

Overview of the 2010 Carbonaceous Aerosols and Radiative Effects Study (CARES)

NASA Technical Reports Server (NTRS)

Zaveri, R. A.; Shaw, W. J.; Cahill, J. F.; Cairns, Brian; Cappa, C. D.; Ottaviani, Matteo; Cziczo, D. J.; Ferrare, Richard A.; Alexander, M. L.; Alexandrov, Mikhail Dmitrievic;

Observational Evidence of Changes in Water Vapor, Clouds, and Radiation at the ARM SGP Site

NASA Technical Reports Server (NTRS)

Dong, Xiquan; Xi, Baike; Minnus, Patrick

2006-01-01

Characterizing water vapor and cloud effects on the surface radiation budget is critical for understanding the current climate because water vapor is the most important greenhouse gas in the atmosphere and clouds are one of the largest sources of uncertainty in predicting potential future climate change. Several studies have shown that insolation over land declined until 1990 then increased until the present. Using 8 years of surface data, we observed the increasing trend of insolation from 1997 to 2000, but detected a significant decrease from 2001 to 2004. The variation of cloud fraction mirrors that of insolation with an overall increase of 1 percent per year. Under clear-sky conditions, water vapor changes have a greater impact on longwave flux than on insolation.