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Sample records for alec christie julian

  1. Sir Alec Clegg

    ERIC Educational Resources Information Center

    Brighouse, Tim

    2008-01-01

    This article is a personal view of the career of Sir Alec Clegg. It outlines some of Clegg's achievements in the West Riding, and why he was so influential on those that he worked with. Finally, it retells one of Alec Clegg's favourite stories "The fable of Fred".

  2. Corpus Christi, Texas

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This near vertical view of the south Texas coast shows the city of Corpus Christi (28.0N, 97.0W) and Corpus Christi Bay. Mustang Island and the Gulf of Mexico are seen in the Southeast corner of the view. The Nueces River flows into the bay from the west. The light toned squiggly lines in Corpus Christi Bay are mud trails caused by shrimp boats dragging their nets along the shallow bottom of the bay.

  3. President of Council-Sir Alec

    ScienceCinema

    None

    2011-04-25

    En décembre 1983 le président de l'Association du Personnel du Cern a suggéré d'inviter le président du conseil à une réunion du personnel dans le but d'améliorer la communication entre le conseil et le personnel. Le DG H.schopper remercie le président du conseil, Sir Alec, d'avoir accepté l'invitation malgré ses nombreux occupations.

  4. 130. Julian Price Memorial Park. Fortyseven acre Julian Price Lake ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    130. Julian Price Memorial Park. Forty-seven acre Julian Price Lake created by an impoundment. Looking west. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  5. Corpus Christi oil port eyed

    SciTech Connect

    Powers, M.B.

    1993-07-05

    The Port of Corpus Christi, Texas, with the support of several oil companies and the blessing of the US Coast Guard, plans to build a $600-million deepwater harbor to accommodate supertankers. The proposed port, Safeharbor, is touted as an environmentally sound solution to current risks associated with off-loading crude oil from very large tankers at shore ports. In a system called lightering, crude now is transferred from supertankers in deep water to smaller vessels that can negotiate shallow channels. While smaller tankers need only 45 ft of water, supertankers need 80 ft. Corpus Christi has the advantage of being closer to deep water than other Gulf ports, but nevertheless, half the proposed project's cost, $300 million, would be for dredging a 10-mile channel to deep water.

  6. 33 CFR 165.808 - Corpus Christi Ship Channel, Corpus Christi, TX, safety zone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... CFR 165.23 apply. (c) The Captain of the Port will notify the maritime community of periods during... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Corpus Christi Ship Channel... § 165.808 Corpus Christi Ship Channel, Corpus Christi, TX, safety zone. (a) The following areas...

  7. 33 CFR 165.808 - Corpus Christi Ship Channel, Corpus Christi, TX, safety zone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CFR 165.23 apply. (c) The Captain of the Port will notify the maritime community of periods during... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Corpus Christi Ship Channel... § 165.808 Corpus Christi Ship Channel, Corpus Christi, TX, safety zone. (a) The following areas...

  8. The man behind the DNA fingerprints: an interview with Professor Sir Alec Jeffreys

    PubMed Central

    2013-01-01

    In this interview we talk with Professor Sir Alec Jeffreys about DNA fingerprinting, his wider scientific career, and the past, present and future of forensic DNA applications. The podcast with excerpts from this interview is available at: http://www.biomedcentral.com/biome/alec-jeffreys. PMID:24245655

  9. H. Julian Allen

    NASA Technical Reports Server (NTRS)

    1957-01-01

    H. Julian Allen stands beside the observation window of the 8 x 7 foot test section of the NACA Ames Unitary Plan Wind Tunnel. H. Julian Allen is best known for his 'Blunt Body Theory' of aerodynamics, a design technique for alleviating the severe re-entry heating problem which was then delaying the development of ballistic missiles. His findings revolutionized the fundamental design of ballistic missle re-entry shapes. Subsequently, applied research led to applications of the 'blunt' shape to ballistic missles and spacecraft which were intended to re-enter the Earth's atmosphere. This application led to the design of ablative heat shields that protected the Mercury, Gemini and Apollo astronauts as their space capsules re- entered the Earth's atmosphere. 'Harvey' Allen as he was called by most, was not only a brilliant scientist and aeronautical engineer but was also admired for his kindness, thoughtfulness and sense of humor. Among his many other accomplishments, Harvey Allen served as Center Director of the NASA Ames Research Center from 1965 to 1969. He died of a heart attack on January 29, 1977 at the age of 66.

  10. 77 FR 2448 - Special Local Regulation; HITS Triathlon; Corpus Christi Bayfront, Corpus Christi, TX

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-18

    ... SECURITY Coast Guard 33 CFR Part 100 RIN 1625-AA08 Special Local Regulation; HITS Triathlon; Corpus Christi... from portions of the Corpus Christi Bayfront area during the HITS Triathlon on February 18th and 19th, 2012. This Special Local Regulation is necessary to ensure the safety of HITS Triathlon...

  11. Corpus Christi, Nueces, and Aransas Bays

    USGS Publications Warehouse

    Handley, Lawrence R.; Spear, Kathryn A.; Eleonor Taylor; Thatcher, Cindy

    2015-01-01

    Corpus Christi Bay and Nueces Bay comprise the middle estuarine portion of Texas’ Coastal Bend region (Figure 1; Burgan and Engle, 2006). Aransas Bay is part of the upper estuarine portion of the region. These bays make up part of the Coastal Bend Bays and Estuaries Program, one of the many estuarine areas in the U.S. Environmental Protection Agency’s National Estuary Program (Holt, 1998). The Coastal Bend region is sub-humid and sub-tropical. Summers are long, hot, and humid, and winters are short and mild. The landscape around the estuaries is dominated by row crops, pastures, and brushy rangeland (Handley and others, 2007). The Nueces River, along with other smaller rivers and creeks, provides freshwater inflow—along with essential nutrients and sediment— into Nueces Bay, which feeds into Corpus Christi Bay (Holt, 1998). Freshwater inflow into the Aransas Bay comes from Mission River, Aransas River, and Copano Creek. The region is relatively dry otherwise and prone to droughts. Corpus Christi receives an average of 76.2 cm (30 in) of rain annually; evaporation usually exceeds 177.8 cm (70 in) (Holt, 1998; Handley and others, 2007). The San Antonio-Nueces Coastal Basin drains into Aransas Bay. The Nueces River basin covers 43,253 km2 (16,700 miles2 ), from northwest of San Antonio, flowing southeast to where it drains into Nueces and Corpus Christi Bays (Holt, 1998). The Nueces-Rio Grande basin covers approximately 18,648 1 U.S. Geological Survey National Wetlands Research Center, 700 Cajundome Blvd., Lafayette, LA 70506 2 Harte Research Institute for Gulf of Mexico Studies, Texas A&M University - Corpus Christi, 6300 Ocean Drive, Unit 5869, Corpus Christi, Texas 78412 2 km2 (7,200 miles2 ) and flows partially into Corpus Christi Bay (as well as the upper Laguna Madre). The inflow from Nueces River has declined by approximately 20 percent over the past several decades, partly due to construction of lakes and reservoirs, particularly Lake Corpus Christi

  12. 77 FR 34034 - Corpus Christi Liquefaction, LLC; Cheniere Corpus Christi Pipeline, L.P.; Notice of Intent To...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-08

    ....; Notice of Intent To Prepare an Environmental Assessment for the Planned Corpus Christi LNG Terminal and... assessment (EA) that will discuss the environmental impacts of the planned Corpus Christi LNG Terminal and... (LNG) export and import terminal, and a natural gas transmission pipeline in Nueces and San...

  13. EEAP lighting survey study at the Corpus Christi Army Depot, Corpus Christi, Texas. Final report

    SciTech Connect

    1995-04-05

    This energy conservation study was performed by Huitt-Zollars Inc, for the U.S. Army Engineer District (USAED), Fort Worth, under contract number DACAC63-94-D-0015. The study was conducted at Corpus Christi Army Depot (CCAD) in Corpus Christi, Texas, between October 3, 1994 and April 5, 1995. The site survey and data collection was performed by C.A. Pieper, P.E. and Tom Luckett, Lighting Designer. The purpose of the study was to perform a limited site survey of specific buildings at the facility, identify specific Energy Conservation Opportunities (ECOs) that exist, and then evaluate these ECOs for technical and economic feasibility. These ECOs were limited to building interior lighting and it`s effects on the heating, ventilating and air conditioning.

  14. EEAP-lighting survey study at the Corpus Christi Army Depot Corpus Christi, Texas. Final report

    SciTech Connect

    1995-04-05

    This energy conservation study was performed by Huitt-Zollars Inc, for the U.S. Army Engineer District (USAED), Fort Worth, under contract number DACAC63-94-D-00l5. The study was conducted at Corpus Christi Army Depot (CCAD) in Corpus Christi, Texas, between October 3, 1994 and April 5, 1995. The site survey and data collection was performed by C.A. Pieper, P.E. and Tom Luckett, Lighting Designer. The purpose of the study was to perform a limited site survey of specific buildings at the facility, identify specific Energy Conservation Opportunities (ECOs) that exist, and then evaluate these ECOs for technical and economic feasibility. These ECOs were limited to building interior lighting and its effects on the heating, ventilating and air conditioning (HVAC) systems.

  15. "The Middle School Cometh"...and Goeth: Alec Clegg and the Rise and Fall of the English Middle School

    ERIC Educational Resources Information Center

    Crook, David

    2008-01-01

    This article identifies Alec Clegg as the leading figure behind the English middle-school movement from the late 1960s. It is argued that the rise of middle schools was sustained by Clegg's astute understanding, which he transmitted to other local education authorities, that the political imperative of comprehensive reorganisation need not…

  16. Subsurface geology of Corpus Christi Bay, Neuces County, Texas

    SciTech Connect

    Collins, J.W.

    1996-09-01

    Prolific production in Corpus Christi Bay has occurred mainly in the regressive Frio Barrier Bar System and the associated shore face-shelf environment. All production in Corpus Christi Bay area is below the Anahuac transgressive wedge with the greatest accumulation in the 1st Marg. sand, which has produced a minimum of 680 BCF of gas in the Red Fish Bay-Mustang Island Common 10 reservoir, the largest single reservoir in South Texas. The 1st Marg. sands have produced in excess of 990 BCFG from four fields in Corpus Christi Bay. Shallow hydrocarbons in Corpus Christi Bay are associated with the South Texas Frio Barrier Bar System and are structurally trapped on large fault bound anticlines or up-to-the-coast relief faults. Deeper production from the Frio Sands is mainly on the Barrier Bar shoreface and associated with fault bounded anticlinal closures. Structural complexity increases with depth especially along the large strike aligned growth faults, some up to 4000 ft displacement, and the associated rollover anticlines. subsidiary faults, and shale plugs. These deeper reservoirs are usually pressure-depletion drives. The oil industry can point with pride to the co-existence with the fragile bay environment while extracting huge reserves. Most of the wells are on State of Texas marine leases and are controlled by State rules and City of Corpus Christi Bay drilling ordinances.

  17. ARM Madden-Julian Oscillation Investigation Experiment

    ScienceCinema

    Long, Chuck

    2014-06-13

    Results of the ARM Madden-Julian Oscillation (MJO) Investigation Experiment (AMIE) field campaign are contributing significantly to concurrent national and international research efforts addressing questions about how the MJO initiates and changes as it passes phenomenon differs in observations versus models.

  18. ARM Madden-Julian Oscillation Investigation Experiment

    SciTech Connect

    Long, Chuck

    2014-03-29

    Results of the ARM Madden-Julian Oscillation (MJO) Investigation Experiment (AMIE) field campaign are contributing significantly to concurrent national and international research efforts addressing questions about how the MJO initiates and changes as it passes phenomenon differs in observations versus models.

  19. Beginning Again: A Response to Rosen and Christie

    ERIC Educational Resources Information Center

    Doecke, Brenton; Breen, Lisa

    2013-01-01

    Genre theory has been around for a long time now. The exchange between Michael Rosen and Frances Christie recently featured in "Changing English" is the latest in a series of exchanges between advocates of genre and their critics over the past three decades or so. Our aim in this response-essay is not to weigh up the merits of the cases…

  20. Initiation of the Madden-Julian Oscillation

    SciTech Connect

    2015-12-14

    Many storms around the world have roots in the Indian Ocean, where they are churned up by the atmospheric process called the Madden-Julian Oscillation (MJO). PNNL is working to unlock the secrets of the MJO, particularly how it initiates in the Indian Ocean every 30-60 days. Better prediction of the MJO will help resource managers, weather forecasters and people worldwide better prepare for its effects.

  1. Madden-Julian Variability in Coupled Models

    SciTech Connect

    Sperber, K R; Gualdi, S; Li, W; Slingo, J M

    2001-12-12

    The Madden-Julian Oscillation (MJO) is a dominant mode of tropical variability (Madden and Julian 1971, 1972). It is manifested on a timescale of {approx}30-70 days through large-scale circulation anomalies which occur in conjunction with eastward propagating convective anomalies over the eastern hemisphere. Recent evidence has suggested that an interactive ocean may be important for the simulation of the Madden-Julian Oscillation (Flatau et al. 1997, Sperber et al. 1997, Waliser et al. 1999, Inness et al. 2002). As part of an initiative to the CLIVAR Working Group on Coupled Modeling, we examine ocean-atmosphere GCMs to ascertain the degree to which they can represent the 4-dimensional space-time structure of the MJO. The eastward propagation of convection is also examined with respect to the surface fluxes and SST, and we compare and contrast the behavior over the Indian Ocean and the western Pacific. Importantly, the results are interpreted with respect to systematic error of the mean state.

  2. A Conversation with Robert F. Christy Part II

    NASA Astrophysics Data System (ADS)

    Lippincott, Sara

    2006-12-01

    Robert F. Christy, Institute Professor of Theoretical Physics Emeritus at Caltech, recalls his wartime work at Los Alamos on the critical assembly for the plutonium bomb (“the Christy bomb”); the Alamogordo test, July 16, 1945; the postwar concerns of ALAS (Association of Los Alamos Scientists); his brief return to the University of Chicago and move to Caltech; friendship with and later alienation from Edward Teller; work with Charles and Tommy Lauritsen and William A. Fowler in Caltech’s Kellogg Radiation Laboratory; Freeman Dyson’s Orion Project; work on the meson and RR Lyrae stars; fellowship at Cambridge University; 1950s Vista Project at Caltech; his opposition to the Strategic Defense Initiative; and his post-retirement work for the National Research Council’s Committee on Dosimetry and on inertial-confinement fusion.

  3. A Conversation with Robert F. Christy Part I

    NASA Astrophysics Data System (ADS)

    Lippincott, Sara

    2006-09-01

    Robert F. Christy, Institute Professor of Theoretical Physics Emeritus at Caltech, recalls his childhood in British Columbia; his undergraduate years at the University of British Columbia; his graduate work with J. Robert Oppenheimer at Berkeley; and his work on the Manhattan Project, first with Enrico Fermi at the Metallurgical Laboratory of the University of Chicago and then as a member of the Theoretical Division at Los Alamos.

  4. Percy Julian, Robert Robinson, and the Identity of Eserethole

    ERIC Educational Resources Information Center

    Ault, Addison

    2008-01-01

    The Nova production "Percy Julian--Forgotten Genius" included the very public disagreement between Percy Julian, an unknown American chemist, and Robert Robinson, possibly the best known organic chemist of the day, as to the identity of "eserethole", the key intermediate for the synthesis of the alkaloid physostigmine. The Nova production,…

  5. Julian B. Rotter (1916-2014).

    PubMed

    Strickland, Bonnie R

    2014-01-01

    One of the most influential psychologists of the 20th century, Julian B. Rotter, died at the age of 97 on January 6, 2014, at his home in Mansfield, Connecticut. Jules was born on October 22, 1916, in Brooklyn, New York, the third son of Jewish immigrant parents. As noted in the citation for his American Psychological Association (APA) Award for Distinguished Scientific Contributions, "his pioneering social learning framework...transformed behavioral approaches to personality and clinical psychology. He integrated the concepts of expectancy and reinforcement and built an enduring early bridge between the psychology of learning and its diverse social, clinical, and personality applications. His seminal studies of the variable of internal versus external locus of control provided the foundation for years of prolific research on choice and perceived control in several disciplines...Julian Rotter, by his writing, teaching, and personal example,...profoundly changed theory and practice in the field" (American Psychologist, 1989, p. 625). He was devoted to his family and shared his insights, his empathy, his compassion, and his admirable social conscience with them, as he did with his myriad friends and students. PMID:25046717

  6. PERSPECTIVE VIEW OF THE C. 1893 HOTEL JULIAN, LOCATED AT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PERSPECTIVE VIEW OF THE C. 1893 HOTEL JULIAN, LOCATED AT 103-107 SECOND STREET, VIEW LOOKING SOUTHEAST. - Corvallis Downtown Historic District, Bounded by First & Sixth Streets, Van Buren & Western Avenues, Corvallis, Benton County, OR

  7. H. Julian Allen with Blunt Body Theory

    NASA Technical Reports Server (NTRS)

    1957-01-01

    H. Julian Allen is best known for his 'Blunt Body Theory' of aerodynamics, a design technique for alleviating the severe re-entry heating problem which was then delaying the development of ballistic missiles. His findings revolutionized the fundamental design of ballistic missle re-entry shapes. Subsequently, applied research led to applications of the 'blunt' shape to ballistic missles and spacecraft which were intended to re-enter the Earth's atmosphere. This application led to the design of ablative heat shields that protected the Mercury, Gemini and Apollo astronauts as their space capsules re- entered the Earth's atmosphere. 'Harvey' Allen as he was called by most, was not only a brilliant scientist and aeronautical engineer but was also admired for his kindness, thoughtfulness and sense of humor. Among his many other accomplishments, Harvey Allen served as Center Director of the NASA Ames Research Center from 1965 to 1969. He died of a heart attack on January 29, 1977 at the age of 66.

  8. EFFECTS OF CORPUS CHRISTI BAY SEDIMENTS ON SURVIVAL, GROWTH AND REPRODUCTION OF THE MYSID, MYSIDOPSIS BAHIA

    EPA Science Inventory

    The study described here examined effects on mortality, growth, reproduction, and behavior of Americamysis bahi exposed under extended static conditions to bedded sediments from Corpus Christi Bay.

  9. Giants of the past: Percy Lavon Julian (1899-1975) a forgotten pioneer in soy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The common thread running through African American chemist Percy Lavon Julian's life is one about outstanding achievements in the face of great obstacles. Racial oppression forced Julian to repeatedly pick up broken fragments of chance and turn them into opportunity. Percy Julian was a luminary in...

  10. Teaching Margery and Julian in Anthology-Based Survey Courses

    ERIC Educational Resources Information Center

    Petersen, Zina

    2006-01-01

    Recognizing that many of us teach the medieval English women mystics Margery Kempe and Julian of Norwich in survey courses, this essay attempts to put these writers in context for teachers who may have only a passing familiarity with the period. Focusing on passages of their writings found in the Longman and Norton anthologies of British…

  11. 129. Julian Price Memorial Park. Price Lake Dam. A concrete ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    129. Julian Price Memorial Park. Price Lake Dam. A concrete slab bridge crosses the top of the dam impounding a forty-seven acre lake. Looking west. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  12. Quarantine Controversy: Kaci Hickox v. Governor Chris Christie.

    PubMed

    Gatter, Robert

    2016-05-01

    Nurse Kaci Hickox is among the "Ebola Fighters" honored by Time magazine as its 2014 Person of the Year, having treated Ebola patients in Sierra Leone while volunteering with Médecins Sans Frontieres. When she returned to the United States in October 2014, she was quarantined in New Jersey for three days before returning home to Maine under the terms of a negotiated release. A year later, in October 2015, Hickox filed suit in federal court against Governor Chris Christie and New Jersey health officials, claiming that the quarantine violated her civil rights. Her complaint asserts that New Jersey officials lacked the authority to quarantine her because she did not pose a significant risk of transmission. The lawsuit raises important questions about disease-transmission risk, the inability of science to rule out certain theoretical risks, and the state's power to quarantine. It also demonstrates that population health depends on respecting individual liberty and using the best available epidemiological data to set public health policy. PMID:27150412

  13. Hydrodynamic characterization of Corpus Christi Bay through modeling and observation.

    PubMed

    Islam, Mohammad S; Bonner, James S; Edge, Billy L; Page, Cheryl A

    2014-11-01

    Christi Bay is a relatively flat, shallow, wind-driven system with an average depth of 3-4 m and a mean tidal range of 0.3 m. It is completely mixed most of the time, and as a result, depth-averaged models have, historically, been applied for hydrodynamic characterization supporting regulatory decisions on Texas coastal management. The bay is highly stratified during transitory periods of the summer with low wind conditions. This has important implications on sediment transport, nutrient cycling, and water quality-related issues, including hypoxia which is a key water quality concern for the bay. Detailed hydrodynamic characterization of the bay during the summer months included analysis of simulation results of 2-D hydrodynamic model and high-frequency (HF) in situ observations. The HF radar system resolved surface currents, whereas an acoustic Doppler current profiler (ADCP) measured current at different depths of the water column. The developed model successfully captured water surface elevation variation at the mouth of the bay (i.e., onshore boundary of the Gulf of Mexico) and at times within the bay. However, large discrepancies exist between model-computed depth-averaged water currents and observed surface currents. These discrepancies suggested the presence of a vertical gradient in the current structure which was further substantiated by the observed bi-directional current movement within the water column. In addition, observed vertical density gradients proved that the water column was stratified. Under this condition, the bottom layer became hypoxic due to inadequate mixing with the aerated surface water. Understanding the disparities between observations and model predictions provides critical insights about hydrodynamics and physical processes controlling water quality. PMID:25096643

  14. 76 FR 55909 - CITGO Refining and Chemicals Company L.P. v. Port of Corpus Christi Authority of Nueces County...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-09

    ... CITGO Refining and Chemicals Company L.P. v. Port of Corpus Christi Authority of Nueces County, Texas... ``Complainant,'' against the Port of Corpus Christi Authority of Nueces County, Texas (PCCA) hereinafter... charges, CITGO has been forced to subsidize costs associated with services provided to other users of...

  15. Investigation of ground-water contamination at a drainage ditch, Installation Restoration Site 4, Naval Air Station Corpus Christi, Corpus Christi, Texas, 2005–06

    USGS Publications Warehouse

    Vroblesky, Don A.; Casey, Clifton C.

    2007-01-01

    The U.S. Geological Survey, in cooperation with the Naval Facilities Engineering Command Southeast, used newly developed sampling methods to investigate ground-water contamination by chlorobenzenes beneath a drainage ditch on the southwestern side of Installation Restoration Site 4, Naval Air Station Corpus Christi, Corpus Christi, Texas, during 2005-06. The drainage ditch, which is a potential receptor for ground-water contaminants from Installation Restoration Site 4, intermittently discharges water to Corpus Christi Bay. This report uses data from a new type of pore-water sampler developed for this investigation and other methods to examine the subsurface contamination beneath the drainage ditch. Analysis of ground water from the samplers indicated that chlorobenzenes (maximum detected concentration of 160 micrograms per liter) are present in the ground water beneath the ditch. The concentrations of dissolved oxygen in the samples (less than 0.05-0.4 milligram per liter) showed that the ground water beneath and near the ditch is anaerobic, indicating that substantial chlorobenzene biodegradation in the aquifer beneath the ditch is unlikely. Probable alternative mechanisms of chlorobenzene removal in the ground water beneath the drainage ditch include sorption onto the organic-rich sediment and contaminant depletion by cattails through uptake, sorption, and localized soil aeration.

  16. IMPACT OF STORM-WATER OUTFALLS ON SEDIMENT QUALITY IN CORPUS CHRISTI BAY, TEXAS, USA

    EPA Science Inventory

    To determine the quality of sediments and extent of contaminant impacts, a Sediment Quality Triad (SQT) study was conducted at 36 sites in the Corpus Christi Bay, Texas, USA, system. Fifteen of the 36 sites were located near storm-water outfalls, but 13 other sites (i.e., industr...

  17. 40 CFR 81.136 - Corpus Christi-Victoria Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Corpus Christi-Victoria Intrastate Air Quality Control Region. 81.136 Section 81.136 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... County, Jackson County, Jim Wells County, Kenedy County, Kleberg County, Lavaca County, Live Oak...

  18. Factors associated with birth defects in the region of Corpus Christi, Texas

    EPA Science Inventory

    In recent years, the Birth Defects Epidemiology & Surveillance Branch of the Texas Department of State Health Services (DSHS) has documented a high prevalence of certain birth defects in the Corpus Christi, TX region. We conducted a case-control study to evaluate associations...

  19. 78 FR 44523 - Reorganization of Foreign-Trade Zone 122 Under Alternative Site Framework; Corpus Christi, Texas

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-24

    ...; Whereas, notice inviting public comment was given in the Federal Register (78 FR 13015-13016, 02/26/2013..., Kleberg and Bee Counties, Texas, within and adjacent to the Corpus Christi Customs and Border...

  20. Does the Madden-Julian Oscillation Modulate Stratospheric Gravity Waves?

    NASA Astrophysics Data System (ADS)

    Moss, Andrew; Wright, Corwin; Mitchell, Nicholas

    2016-04-01

    The circulation of the stratosphere is strongly influenced by the fluxes of gravity waves propagating from tropospheric sources. In the tropics, these gravity waves are primarily generated by convection. The Madden-Julian Oscillation (MJO) dominates the intra-seasonal variability of this convection. However, the connection between the MJO and the variability of stratospheric gravity waves is largely unknown. Here we examine gravity-wave potential energy at a height of 26 km and the upper tropospheric zonal-wind anomaly of the MJO at the 200 hPa level, sorted by the relative phase of the MJO using the RMM MJO indices. We show that a strong anti-correlation exists between gravity-wave potential energy and the MJO eastward wind anomaly. We propose that this correlation is a result of the filtering of ascending waves by the MJO winds. The study provides evidence that the MJO contributes significantly to the variability of stratospheric gravity waves in the tropics.

  1. A Madden-Julian Oscillation in Tropospheric Ozone

    NASA Technical Reports Server (NTRS)

    Ziemke, J. R.; Chandra, S.

    2003-01-01

    This is the first study to indicate a Madden-Julian Oscillation (MJO) in tropospheric ozone. Tropospheric ozone is derived using differential measurements of total column ozone and stratospheric column ozone measured from total ozone mapping spectrometer (TOMS) and microwave limb sounder (MLS) instruments. Two broad regions of significant MJO signal are identified in the tropics, one in the western Pacific and the other in the eastern Pacific. Over both regions, MJO variations in tropospheric ozone represent 5-10 Dobson Unit (DU) peak-to-peak anomalies. These variations are significant compared to mean background amounts of 20 DU or less over most of the tropical Pacific. MJO signals of this magnitude would need to be considered when investigating and interpreting particular pollution events since ozone is a precursor of the hydroxyl (OH) radical, the main oxidizing agent of pollutants in the lower atmosphere.

  2. Statistical forecasts of the Madden-Julian Oscillation

    NASA Astrophysics Data System (ADS)

    Jones, C.; Carvalho, L.; Higgins, W.; Waliser, D.; Schemm, J.-K.

    2003-04-01

    Tropical intraseasonal convective anomalies (TICA) play a significant role in the coupled ocean-atmosphere system and the Madden-Julian Oscillation (MJO) is the primary mode of this variability. The two main aspects investigated in this study are: 1) differences in predictive skill of TICA events with different eastward propagation characteristics; 2) differences in predictive skill of TICA events occurring in different phases of El Niño/Southern Oscillation (ENSO). Twenty two years of outgoing longwave radiation (OLR) is used to identify eastward propagating convective anomalies. A statistical forecast model based on lagged linear regression of the first two principal components from a combined empirical orthogonal function (EOF) analysis of intraseasonally filtered OLR, zonal wind components at 200 hPa and 850 hPa anomalies is developed. The forecast model shows useful skill out to about 25 days when validated against filtered anomalies. The presentation will also discuss the statistical forecast skill in real-time.

  3. Climbing the Mountain - The Scientific Biography of Julian Schwinger

    NASA Astrophysics Data System (ADS)

    Mehra, Jagdish; Milton, Kimball

    2000-08-01

    This is the first biography ever written on the distinguished physicist Julian Schwinger. Schwinger was one of the most important and influential scientists of the twentieth century. The list of his contributions is staggering, from his early work leading to the Schwinger action principle, Euclidean quantum field theory, and the genesis of the standard model, to later valuable work on magnetic charge and the Casimir effect. He also shared the 1965 Nobel Prize in Physics with Richard Feynman. However, even among physicists, understanding and recognition of his work remains limited. This book by Mehra and Milton, both of whom were personally acquainted with Schwinger, presents a unique portrait that sheds light on both his personality and his work through discussion of his lasting influence on science. Anyone who wishes to gain a deeper understanding of one of the great physicists of this century needs to read this book.

  4. Does the Madden-Julian Oscillation modulate stratospheric gravity waves?

    NASA Astrophysics Data System (ADS)

    Moss, Andrew C.; Wright, Corwin J.; Mitchell, Nicholas J.

    2016-04-01

    The circulation of the stratosphere is strongly influenced by the fluxes of gravity waves propagating from tropospheric sources. In the tropics, these gravity waves are primarily generated by convection. The Madden-Julian Oscillation (MJO) dominates the intraseasonal variability of this convection. However, the influence of the MJO on the variability of stratospheric gravity waves is largely unknown. Here we examine gravity wave potential energy at 26 km and the upper tropospheric zonal wind anomaly of the MJO at 200 hPa, sorted by the relative phase of the MJO using the Real Multivariate MJO indices. We show that a strong anticorrelation exists between gravity wave potential energy and the MJO eastward wind anomaly. We propose that this correlation is a result of the filtering of upward propagating waves by the MJO winds. The study provides the first observational evidence that the MJO contributes significantly to the global variability of stratospheric gravity waves in the tropics.

  5. Julian Lennon Is Global Ambassador for the Lupus Foundation of America

    MedlinePlus

    ... Julian Lennon Is Global Ambassador for the Lupus Foundation of America Past Issues / Spring 2014 Table of ... now serving as Global Ambassador for the Lupus Foundation of America. What do you hope to achieve ...

  6. Geology and nickel mineralization of the Julian-Cuyamaca area, San Diego County, California

    USGS Publications Warehouse

    Creasey, S.C.

    1946-01-01

    The Julian-Cuyamaca area is in the San Diego Mountains, one of the Peninsular Ranges of southern California. It lies in San Diego County, about 3 miles south of Julian, and approximately 60 miles northeast of San Diego. The area was mapped, and its nickel mineralization studied, from March to June, 1944; the work was part of the U. S. Geological Survey's program of strategic mineral investigations.

  7. The heliocentric system from the Orphic Hymns and the Pythagoreans to emperor Julian

    NASA Astrophysics Data System (ADS)

    Theodossiou, Efstratios; Dacanalis, Aris; Dimitrijević, Milan, S.; Mantarakis, Petros

    The evolution of the heliocentric theory in the antiquity has been analyzed, from the first seeds in the Orphic Hymns to the emperor Julian, also called "the Apostate" in the 4th century A.D. In particular the Orphic Hymns, views of Pythagoreans, as well as the heliocentric ideas of Philolaus of Croton, Icetas, Ecphantus, Heraclides of Pontos, Anaximander, Seleucus of Seleucia, Aristarchus of Samos and Emperor Julian were analyzed.

  8. The ethnobotany of Christ's Thorn Jujube (Ziziphus spina-christi) in Israel

    PubMed Central

    Dafni, Amots; Levy, Shay; Lev, Efraim

    2005-01-01

    This article surveys the ethnobotany of Ziziphus spina-christi (L.) Desf. in the Middle East from various aspects: historical, religious, philological, literary, linguistic, as well as pharmacological, among Muslims, Jews, and Christians. It is suggested that this is the only tree species considered "holy" by Muslims (all the individuals of the species are sanctified by religion) in addition to its status as "sacred tree " (particular trees which are venerated due to historical or magical events related to them, regardless of their botanical identity) in the Middle East. It has also a special status as "blessed tree" among the Druze. PMID:16270941

  9. The Hydrological Cycle of the Madden-Julian Oscillation

    NASA Astrophysics Data System (ADS)

    Waliser, D.; Tian, B.; Schwartz, M.; Liu, T.; Fetzer, E.

    2007-12-01

    The Madden-Julian Oscillation (MJO) is the dominant form of intra-seasonal variability in the Tropics and it impacts a wide range of phenomena, such as El Nino/La Nina, Asian-Australian monsoons, mid-latitude weather, and tropical cyclones. Despite the prominent impacts of the MJO and its potential predictability with lead times on the order of weeks, our weather and climate models have a relatively poor representation of the MJO and our environmental predictions suffer from this shortcoming. To date, the large-scale MJO convection and circulation characteristics have been relatively well documented and in some cases understood. For the most part, these studies have focused on quantities such as upper and lower level winds, outgoing longwave radiation and precipitation, and surface heat budget processes. In recent years, a number of studies have also documented aspects of the MJO's vertical structure impacts on biology and composition. In this study, we focus on the hydrological cycle of the MJO. With the addition of a number of new satellite products in recent years, it is possible to more completely describe most aspects of the hydrological cycle of the MJO. We build on recent work with AIRS water vapor and MLS cloud ice profiles to document and discuss the variations in rainfall (TRMM, CMAP), surface evaporation (derived via SSM/I etc), vertical profiles of moisture (AIRS), column moisture convergence (QuikScat, SSM/I), and cloud liquid (SSM/I) and ice water (MLS).

  10. The Madden-Julian Oscillation in General Circulation Models

    SciTech Connect

    Sperber, K R; Gleckler, P J; Doutriaux, C; Groups, A M; Groups, C M; Slingo, J M; Inness, P M; Gualdi, S; Li, W

    2003-10-27

    A methodology is utilized to analyze in a standardized fashion the Madden-Julian Oscillation (MJO) in general circulation models. This is attained by projecting 20-100 day bandpass filtered outgoing longwave radiation (OLR) from the models onto the two leading empirical orthogonal functions (EOF's) of observed OLR that characterize the propagation of MJO convection from the Indian Ocean to the central Pacific Ocean. The resulting principal component time series are then screened to isolate boreal winters during which they exhibit a lead-lag relationship consistent with observations. This PC subset is used for linear regression to determine the ability of the models to simulate the observed spacetime variability of the MJO. The vast majority of models underestimate the amplitude of the MJO convective anomalies by a factor of two or more, and the eastward propagation of convection is less coherent than observed, typically. For a given family of models, coupling to an ocean leads to better organization of the large-scale convection. The low-level moisture convergence mechanism for eastward propagation is represented in limited cases, as is the vertical structure of the MJO.

  11. Tracking Pulses of the Madden-Julian Oscillation

    SciTech Connect

    Yoneyama, Kunio; Zhang, Chidong; Long, Charles N.

    2013-12-13

    An international field campaign aiming at atmospheric and oceanic processes associated with the Madden-Julian Oscillation (MJO) was conducted in and around the tropical Indian Ocean (IO) during October 2011 - March 2012. The objective of the field campaign was to collect observations urgently needed to expedite the progress of understanding the key processes of the MJO, focusing on its initiation but also including propagation and maturation, and ultimately to improve skills of numerical simulation and prediction of the MJO. Primary targets of the field campaign include interaction of atmospheric deep convection with its environmental moisture, evolution of cloud populations, and air-sea interaction. Several MJO events were captured by ground-based, airborne, and oceanic instruments with advanced observing technology. Numerical simulations and real-time forecasts were integrated components of the field campaign in its design and operation. Observations collected during the campaign provide unprecedented opportunities to reveal detailed processes of the MJO and to assist evaluation, improvement and development of weather and climate models. The data policy of the campaign encourages the broad research community to use the field observations to advance the MJO study.

  12. The Madden-Julian Oscillation in a Warming World

    NASA Astrophysics Data System (ADS)

    Chang, Chuing-Wen June; Tseng, Wan-Ling; Hsu, Huang-Hsiung; Keenlyside, Noel; Tsuang, Ben-Jei

    2015-04-01

    Climate models remain challenged by accurate simulation of the Madden- Julian oscillation (MJO). This has limited the study of the impact of global warming on this phenomenon. He we apply the newly developed ECHAM5-SIT coupled model that is able simulate the MJO with realistic strength, structure, period, and propagation speed. The model consists of a high-resolution one-column ocean model (SIT) coupled to the ECHAM5 atmospheric model. Numerical experiments were conducted to explore the changes in the MJO by the end of 21st Century under the RCP8.5 scenario. In the warming climate, the MJO remains wavenumber-one structure with larger amplitude and stronger circumglobal propagation, and faster eastward propagation. The convection develops higher in the upper troposphere and the overturning circulation expands zonally but contracts meridionally. The shallow and deep convective heating are both enhanced and a stronger low-level convergence enhances westward tilting with height. Enhancement of MJO amplitude and extent can be explained by enhanced intraseasonal low-level convergence and increased mean moisture under global warming. The moister mean state contributes to the enhancement of deep convection, which excites stronger Kelvin waves. This reinforces low-level convergence through the enhanced Frictional Convergence Mechanism and leads to the more efficient and timely preconditioning of the deep convection, and therefore to a faster development and enhancement of the deep convection in MJO.

  13. Julian Huxley, Uca pugnax and the allometric method.

    PubMed

    Packard, Gary C

    2012-02-15

    The allometric method, which often is attributed to Julian Huxley, entails fitting a straight line to logarithmic transformations of the original bivariate data and then back-transforming the resulting equation to form a power function in the arithmetic scale. Development of the technique was strongly influenced by Huxley's own research on growth by the enlarged 'crusher' claw in male fiddler crabs (Uca pugnax). Huxley reported a discontinuity in the log-log plot of chela mass vs body mass, which he interpreted as an abrupt change in relative growth of the chela at about the time crabs attain sexual maturity. My analysis of Huxley's arithmetic data indicates, however, that the discontinuity was an artifact caused by logarithmic transformation and that dynamics of growth by the crusher claw do not change at any point during development. Arithmetic data are well described by a power function fitted by nonlinear regression but not by one estimated by back-transforming a line fitted to logarithms. This finding and others like it call into question the continued reliance on the allometric method in contemporary research. PMID:22279062

  14. Maps showing textural characteristics of benthic sediments in the Corpus Christi Bay estuarine system, south Texas

    USGS Publications Warehouse

    Shideler, Gerald L.; Stelting, Charles E.; McGowen, Joseph H.

    1981-01-01

    Corpus Christi Bay is a heavily used estuary on the south Texas coast in the northwest Gulf of Mexico (fig. 1).  The Bay is stressed by diverse activities which could substantially affect its ecosystem.  Such activities include shipping, resource production (oil, gas, and construction aggregate), commercial and sport fishing, and recreation.  Shipping activities alone have had a substantial impact on the bay.  For example, the past maintenance of navigation channels has required extensive dredging and spoil disposal within the estuarine system.  Numerous subaqueous spoil disposal sites and subaerial spoil banks are present throughout the bay (fig. 1), and the selection of future spoil disposal sites is becoming a critical local problem.  As activities in the bay increase, the need for effective environmental management becomes increasingly important, and effective management necessitates a good understanding of the bay's physical characteristics.  The objective of this study is to provide detailed information about the textural composition of bottom sediments within the estuarine system, information which could be used in making environmental-management decisions.  Visual descriptions of bottom sediments in Corpus Christi Bay and adjacent areas have been presented by McGowen and Morton (1979).  Additionally, a study of the textures of sediments on the Inner Continental Shelf adjacent to the bay has been presented by Shideler and Berryhill (1977).

  15. Does the Madden-Julian Oscillation Influence Aerosol Variability?

    NASA Astrophysics Data System (ADS)

    Tian, B.; Waliser, D. E.; Kahn, R. A.; Li, Q.; Yung, Y. L.; Tyranowski, T.; Geogdzhayev, I. V.; Mishchenko, M. I.; Torres, O.; Smirnov, A.

    2007-12-01

    We investigate the modulation of aerosols by the Madden-Julian Oscillation (MJO) using satellite-based global aerosol products, including aerosol index (AI) from the Total Ozone Mapping Spectrometer (TOMS) on Nimbus-7, and aerosol optical thickness (AOT) from the Moderate Resolution Imaging Spectroradiometer (MODIS) on Terra and Aqua and the Advanced Very High Resolution Radiometer (AVHRR) on NOAA satellites. A composite analysis is performed for boreal winter, and the global pentad rainfall data from the NOAA Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP) are used to identify MJO events. The MJO composites exhibit large variations in the TOMS AI and MODIS/AVHRR AOT over the equatorial Indian and western Pacific Oceans where MJO convection is active, as well as the tropical Africa and Atlantic Ocean where MJO convection is relatively weak but the background aerosol level is relatively high. A strong inverse linear relationship between the TOMS AI and rainfall anomalies, but a weaker, less coherent positive correlation between the MODIS/AVHRR AOT and rainfall anomalies, were found. The Aerosol Robotic Network AOT pattern at Kaashidoo (73.5°E, 4.9°N) and Nauru (167°E, 0.5°S) is more consistent with MODIS and AVHRR. These results indicate a connection between the MJO, its associated rainfall and circulation variability, and the observed aerosol variations. Several physical and non-physical factors that may contribute to the observed aerosol-rainfall relationship, such as aerosol humidification effect, wet deposition, surface wind speed, phytoplankton, different sensor sensitivities (absorbing versus non-absorbing aerosols and upper versus lower tropospheric aerosols), sampling issue, and cloud contamination, are discussed. However, a clear causal explanation for the observed patterns remains elusive. Further investigation is needed to unravel this complex aerosol-rainfall relationship.

  16. The life cycle of the Madden-Julian oscillation

    NASA Technical Reports Server (NTRS)

    Hendon, Harry H.; Salby, Murry L.

    1994-01-01

    A composite life cycle of the Madden-Julian oscillation (MJO) is constructed from the cross covariance between outgoing longwave radiation (OLR), wind, and temperature. To focus on the role of convection, the composite is based on episodes when a discrete signal in OLR is present. The composite convective anomaly possesses a predominantly zonal wavenumber 2 structure that is confined to the eastern hemisphere. There, it propagates eastward at about 5 m/s and evolves through a systematic cycle of amplification and decay. Unlike the convective anomaly, the circulation anomaly is not confined to the eastern hemisphere. The circulation anomaly displays characteristics of both a forced response, coupled to the convective anomaly as it propagates across the eastern hemisphere, and a radiating response, which propagates away from the convective anomaly into the western hemisphere at about 10 m/s. The forced response appears as a coupled Rossby-Kelvin wave while the radiating response displays predominantly Kelvin wave features. When it is amplifying, the convective anomaly is positively correlated to the temperature perturbation, which implies production of eddy available potential energy (EAPE). A similar correlation between upper-tropospheric divergence and temperature implies conversion of EAPE to eddy kinetic energy during this time. When it is decaying, temperature has shifted nearly into quadrature with convection, so their correlation and production of EAPE are then small. The same correspondence to the amplification and decay of the disturbance is mirrored in the phase relationship between surface convergence and anomalous convection. The correspondence of surface convergence to the amplification and decay of the convective anomaly suggests that frictional wave- Conditional Instability of the Second Kind (CISK) plays a key role in generating the MJO.

  17. Intraseasonal isotopic variation associated with the Madden-Julian Oscillation

    NASA Astrophysics Data System (ADS)

    Kurita, Naoyuki; Noone, David; Risi, Camille; Schmidt, Gavin A.; Yamada, Hiroyuki; Yoneyama, Kunio

    2011-12-01

    The Madden-Julian Oscillation (MJO) is the dominant mode of intraseasonal variability in the tropical atmosphere. This study examines the evolution of the hydrologic regime from before the onset of the MJO (pre-onset period) to the MJO onset period, using deuterated water vapor (HDO) measurements from the Tropospheric Emission Spectrometer (TES) and from ground-based stations. Ground-based observations reveal a clear transition between high HDO/H2O isotope ratios during the pre-onset period to a period of repeated abrupt decreases in the HDO/H2O isotope ratio associated with intense convection. Each observed minimum in the HDO/H2O ratio corresponded to a maximum in stratiform rainfall fraction, which was derived independently from radar precipitation coverage area. The ground-based observations are consistent with the satellite observations of the HDO/H2O ratio. In order to attribute the mechanisms that bring about the isotopic changes within the MJO convection, an isotope-enabled general circulation model (GCM) constrained by observed meteorological fields was used to simulate this MJO period. The GCM reproduced many of the observed isotopic features that accompanied the onset of an MJO. After the development of deep convection, large-scale stratiform cloud cover appears, and isotope ratios respond, as a consequence of diffusive exchange between stratiform raindrops and the surrounding vapor. In this diffusive exchange process, heavy isotopes tend to become enriched in precipitation and depleted in the surrounding vapor, and thus successive stratiform rainfall results in decreasing isotope values in the middle and lower troposphere. On the basis of these characteristics, isotope tracers can be used to partition stratiform and convective rainfall from observed isotope data and to validate the simulated proportions of convective/stratiform rainfall.

  18. Modulation of Atlantic Aerosols by the Madden-Julian Oscillation

    NASA Technical Reports Server (NTRS)

    Tian, B.; Waliser, D. E.; Kahn, Ralph A.; Wong, S.

    2010-01-01

    Much like the better-known EI Nino-Southern Oscillation, the Madden-Julian Oscillation (MJO) is a global-scale atmospheric phenomenon. The MJO involves periodic, systematic changes in the distribution of clouds and precipitation over the western Pacific and Indian oceans, along with differences in wind intensity over even more extensive areas, including the north and subtropical Atlantic Ocean. The lead authors of this paper developed a sophisticated mathematical technique for mapping the spatial and temporal behavior of changes in the atmosphere produced by the MJO. In a previous paper, we applied this technique to search for modulation of airborne particle amount in the eastern hemisphere associated with the "wet" (cloudy) vs. "dry" phases of the MJO. The study used primarily AVHRR, MODIS, and TOMS satellite-retrieved aerosol amount, but concluded that other factors, such as cloud contamination of the satellite signals, probably dominated the observed variations. The current paper looks at MJO modulation of desert dust transport eastward across the Atlantic from northern Africa, a region much less subject to systematic cloud contamination than the eastern hemisphere areas studied previously. In this case, a distinct aerosol signal appears, showing that dust is transported westward much more effectively during the MJO phase that favors westward-flowing wind, and such transport is suppressed when the MJO reduces these winds. Aside form the significant achievement in identifying such an effect, the result implies that an important component of global dust transport can be predicted based on the phase of the MJO. As a consequence, the impact of airborne dust on storm development in the Atlantic, and on dust deposition downwind of the desert sources, can also be predicted and more accurately modeled.

  19. 33 CFR 3.40-35 - Sector Corpus Christi Marine Inspection Zone and Captain of the Port Zone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Sector Corpus Christi Marine Inspection Zone and Captain of the Port Zone. 3.40-35 Section 3.40-35 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY GENERAL COAST GUARD AREAS, DISTRICTS, SECTORS, MARINE INSPECTION ZONES, AND CAPTAIN OF THE PORT...

  20. 33 CFR 3.40-35 - Sector Corpus Christi Marine Inspection Zone and Captain of the Port Zone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Sector Corpus Christi Marine Inspection Zone and Captain of the Port Zone. 3.40-35 Section 3.40-35 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY GENERAL COAST GUARD AREAS, DISTRICTS, SECTORS, MARINE INSPECTION ZONES, AND CAPTAIN OF THE PORT...

  1. 78 FR 37792 - Mario Julian Martinez-Bernache, Inmate Number #95749-279, CI Big Spring, Corrections Institution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-24

    ... Bureau of Industry and Security Mario Julian Martinez-Bernache, Inmate Number 95749-279, CI Big Spring... 15, 2012, in the U.S. District Court, Southern District of Texas, Mario Julian Martinez-Bernache (``Martinez-Bernache'') was convicted of violating Section 38 of the Arms Export Control Act (22 U.S.C....

  2. Simplified metrics for the identification of the Madden-Julian oscillation in models

    SciTech Connect

    Sperber, Kenneth R.; Kim, Daehyun

    2012-07-01

    We propose simplified metrics to evaluate the fidelity with which the Madden–Julian oscillation (MJO) is simulated in climate models. These metrics are based on lag correlation analysis of principal component time series (PCs). The PCs are obtained by projecting simulated 20–100 day bandpass filtered daily outgoing longwave radiation onto the two leading empirical orthogonal functions of observed MJO variability. The simplified MJO metrics, the maximum positive correlation and time lag at which it occurs, provide consistent information relative to more complex diagnostics developed by the Madden–Julian Oscillation Working Group (CLIVAR MJOWG) and by Kim et al.

  3. Hydrogeochemical and stream sediment reconnaissance basic data for Corpus Christi NTMS quadrangle, Texas

    SciTech Connect

    Not Available

    1980-05-31

    Results of a reconnaissance geochemical survey of the Corpus Christi Quadrangle, Texas, are reported. Field and laboratory data are presented for 119 groundwater samples and 57 stream sediment samples. Also included is a brief discussion on the geology and hydrology of the quadrangle. Groundwater data indicate that uranium concentrations above the 85th percentile occur primarily in a trend in western Nueces County. With one exception, waters in the trend are produced from the Evangeline aquifer and have high values for selenium and strontium. Owing to urbanization, low topographic relief, and the presence of Recent-to-Pleistocene surface material, stream sediment data were found to be less than optimum for the determination of the potential for uranium mineralization, and variation in uranium concentrations between units may simply reflect lithologic differences.

  4. A mobile monitoring system to understand the processes controlling episodic events in Corpus Christi Bay.

    PubMed

    Islam, Mohammad Shahidul; Bonner, James S; Ojo, Temitope O; Page, Cheryl

    2011-04-01

    Corpus Christi Bay (TX, USA) is a shallow wind-driven bay and thereby, can be characterized as a highly pulsed system. It cycles through various episodic events such as hypoxia, water column stratification, sediment resuspension, flooding, etc. Understanding of the processes that control these events requires an efficient observation system that can measure various hydrodynamic and water quality parameters at the multitude of spatial and temporal scales of interest. As part of our effort to implement an efficient observation system for Corpus Christi Bay, a mobile monitoring system was developed that can acquire and visualize data measured by various submersible sensors on an undulating tow-body deployed behind a research vessel. Along with this system, we have installed a downward-looking Acoustic Doppler Current Profiler to measure the vertical profile of water currents. Real-time display of each measured parameter intensity (measured value relative to a pre-set peak value) guides in selecting the transect route to capture the event of interest. In addition, large synchronized datasets measured by this system provide an opportunity to understand the processes that control various episodic events in the bay. To illustrate the capability of this system, datasets from two research cruises are presented in this paper that help to clarify processes inducing an inverse estuary condition at the mouth of the ship channel and hypoxia at the bottom of the bay. These measured datasets can also be used to drive numerical models to understand various environmental phenomena that control the water quality of the bay. PMID:20556650

  5. Madden Julian Oscillation impacts on global ocean surface waves

    NASA Astrophysics Data System (ADS)

    Marshall, Andrew G.; Hendon, Harry H.; Durrant, Tom H.; Hemer, Mark A.

    2015-12-01

    We assess the impact of the tropical Madden Julian Oscillation (MJO) on global ocean wind waves using 30 years of wave data from a wave model hindcast that is forced with high resolution surface winds from the NCEP-CFSR reanalysis. We concentrate on the boreal winter season when the MJO has its greatest amplitude and is potentially a source of predictable wave impacts at intra-seasonal lead times. Statistically significant anomalies in significant wave height (Hs), peak wave period (Tp) and zonal wave energy flux (CgE) are found to covary with the intra-seasonal variation of surface zonal wind induced by the MJO as it traverses eastward from the western tropical Indian Ocean to the eastern tropical Pacific. Tp varies generally out of phase with Hs over the life cycle of the MJO, indicating that these MJO-wave anomalies are locally wind-generated rather than remotely generated by ocean swell. Pronounced Hs anomalies develop on the northwest shelf of Australia, where the MJO is known to influence sea level and surface temperatures, and in the western Caribbean Sea and Guatemalan-Panama Seas with enhanced wave anomalies apparent in the vicinity of the Tehuantepec and Papagayo gaps. Significant wave anomalies are also detected in the North Pacific and North Atlantic oceans in connection with the MJO teleconnection to the extratropics via atmospheric wave propagation. The impact in the north Atlantic stems from induction of the high phase of the North Atlantic Oscillation (NAO) about 1 week after MJO convection traverses the Indian Ocean, and the low phase of the NAO about one week after suppressed convection traverses the Indian Ocean. Strong positive Hs anomalies maximize on the Northern European coast in the positive NAO phase and vice versa for the negative NAO phase. The MJO also influences the occurrence of daily low (below the 5th percentile) and high (above the 95th percentile) wave conditions across the tropics and in the North Pacific and North Atlantic

  6. Establishment of the United States Navy Mine Warfare Center of Excellence in the Corpus Christi Bay Area, Texas

    SciTech Connect

    Kosclski, J.L.; Boyer, R.; Sloger, W.

    1997-08-01

    The proposed establishment of the US Navy Mine Warfare Center of Excellence (MWCE) in the Corpus Christi Bay Area, Texas, involved the collocation of the Navy`s Mine Warfare and Mine Counter Measures assets in proximity to each other at Naval Station (NAVSTA) Ingleside and Naval Air Station (NAS) Corpus Christi, Texas. Collocation of these Navy forces would provide significant advantages in meeting mission and operational requirements. This action would improve the operational training and readiness of the forces. In addition to new construction or modifications at NAVSTA Ingleside, NAS Corpus Christi, and off-base; the establishment of offshore training and operating areas was required. When the project was first proposed in 1993, considerable concern was expressed by environmental interests, shrimpers, and state and federal resource agencies regarding the impact of the proposed training activities within Gulf waters. The Navy and Turner Collie and Braden, Inc., under contract to the Navy, conducted several technical studies and extensive coordination with concerned interests during the environmental impact statement process to identify and document the potential intensity, magnitude, and duration of impact from each proposed training activity.

  7. Julian Lennon Is Global Ambassador for the Lupus Foundation of America | NIH MedlinePlus the Magazine

    MedlinePlus

    ... turn JavaScript on. Feature: Lupus Julian Lennon Is Global Ambassador for the Lupus Foundation of America Past ... disease. You mentioned you are now serving as Global Ambassador for the Lupus Foundation of America. What ...

  8. Impact of storm-water outfalls on sediment quality in Corpus Christi Bay, Texas, USA

    SciTech Connect

    Carr, R.S.; Montagna, P.A.; Biedenbach, J.M.; Kalke, R.; Kennicutt, M.C.; Hooten, R.; Cripe, G.

    2000-03-01

    To determine the quality of sediments and extent of contaminant impacts, a Sediment Quality Triad (SQT) study was conducted at 36 sites in the Corpus Christi Bay, Texas, USA, system. Fifteen of the 36 sites were located near storm-water outfalls, but 13 other sites (i.e., industrial and domestic outfalls, oil field-produced water discharges, and dredging activity) and eight reference sites were also evaluated. Sediment samples were collected and analyzed for physical-chemical characteristics, contaminant concentrations (metals, polycyclic aromatic hydrocarbons [PAHs], polychlorinated biphenyls [PCBs], and pesticides), toxicity, and a benthic index of biotic integrity (BIBI) composed of 10 independent metrics calculated for each site. This large data matrix was reduced using multivariate analysis to create new variables for each component representing overall means and containing most of the variance in the larger data set. The new variables were used to conduct the correlation analysis. Toxicity was significantly correlated with both chemistry and ecological responses, whereas no correlations between the benthic metrics and sediment chemistry were observed. Using the combined information from the SQT, four of the five most degraded sites were storm-water outfall sites. Although estuaries are naturally stressful environments because of salinity and temperature fluctuations, this ecosystem appears to have been compromised by anthropogenic influences similar to what has been observed for other heavily urbanized bay systems along the Texas and Gulf coast.

  9. Cytotoxicity of different extracts of arial parts of Ziziphus spina-christi on Hela and MDA-MB-468 tumor cells

    PubMed Central

    Jafarian, Abbas; Zolfaghari, Behzad; Shirani, Kobra

    2014-01-01

    Background: It has been shown that plants from the family Rhamnaceae possess anticancer activity. In this study, we sought to determine if Ziziphus spina-christi, a species from this family, has cytotoxic effect on cancer cell lines. Materials and Methods: Using maceration method, different extracts of leaves of Z. spina-christi were prepared. Hexane, chloroform, chloroform-methanol (9:1), methanol-water (7:1) methanol, butanol and water were used for extraction, after preliminary phytochemical analyses were done. The cytotoxic activity of the extracts against Hela and MDA-MB-468 tumor cells was evaluated by MTT assay. Briefly, cells were seeded in microplates and different concentrations of extracts were added. After incubation of cells for 72 h, their viability was evaluated by addition of tetrazolium salt solution. After 3 h medium was aspirated, dimethyl sulfoxide was added and absorbance was determined at 540 nm with an ELISA plate reader. Extracts were considered cytotoxic when more than 50% reduction on cell survival was observed. Results: Hexane, chloroform, chloroform-methanol, butanol, methanol-water and aqueous extracts of Z. spina-christi significantly and concentration-dependently reduced viability of Hela and MAD-MB-468 cells. In the both cell lines, chloroform-methanol extract of Z. spina-christi was more potent than the other extracts. Results: From the finding of this study it can be concluded that Z. spina-christi is a good candidate for further study for new cytotoxic agents. PMID:24627846

  10. Evaluation of electrodialysis for chronic acid recovery and purification at Corpus Christi Army Depot. Final report, Oct 89-Apr 91

    SciTech Connect

    Davis, J.S.

    1991-09-01

    A large quantity of hazardous waste is generated during the maintenance, repair, and overhaul of a wide variety of military equipment at Army depots. Some of this waste is generated by the use of chromic acid solutions for chromium electroplating and the application and removal of chromate conversion coatings. Hazardous waste results when metal contamination builds up in the solutions to such a degree that the solutions must be disposed of as hazardous waste. Removal of this metal contamination should result in a lengthened bath life and reduced hazardous wate generation. As part of its pollution abatement and environmental control mission, the U.S. Army Toxic and Hazardous Materials Agency (USATHAMA) is pursuing R and D projects to assist depots in meeting the Army goal of a 50 percent reduction in hazardous waste by the end of 1992 compared with 1985 baseline levels. In one project, USATHAMA purchased, installed, operated, and evaluated an electrodialysis system on two chromic acid process solutions at Corpus Christi Army Depot (CCAD) in Corpus Christi, Texas. The objective of this task was to evaluate the system's ability to remove metal contamination and oxidize trivalent chromium (an impurity) to hexavalent chromium (chromic acid).

  11. Geologic map of the Julian 7.5' quadrangle, San Diego County, California

    USGS Publications Warehouse

    Todd, Victoria R.

    2015-01-01

    Jurassic plutons in the Julian quadrangle underwent synkinematic metamorphism with the result that plutonic contacts and foliation are concordant with those in the surrounding metamorphosed country rocks. Foliation in Jurassic plutons consists of the planar orientation of recrystallized mineral grains and aggregates; deformation textures include augen gneiss, mylonitic gneiss, and mylonite. Structural studies indicate that a significant part of this deformation took place in the Cretaceous and, therefore, the regional foliation in this part of the batholith clearly postdates intrusion of many Cretaceous plutons.

  12. 76 FR 68188 - Valero Refining-Texas, L.P. v. Port of Corpus Christi Authority of Nueces County, TX; Notice of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-03

    ... From the Federal Register Online via the Government Publishing Office FEDERAL MARITIME COMMISSION Valero Refining-Texas, L.P. v. Port of Corpus Christi Authority of Nueces County, TX; Notice of Filing of Complaint and Assignment Notice is given that a complaint has been filed with the Federal Maritime Commission (Commission) by...

  13. Distribution, abundance, and resting microhabitat of burbot on Julian's Reef, southwestern Lake Michigan

    USGS Publications Warehouse

    Edsall, Thomas A.; Kennedy, Gregory W.; Horns, William H.

    1993-01-01

    We used a remotely operated submersible vehicle equipped with a color video camera to videotape the lake bed and document the distribution and abundance of burbot Lota lota on a 156-hectare portion of Julian's Reef in southwestern Lake Michigan. The substrates and bathymetry of the study area had been mapped recently by side-scan sonar. Burbot density determined from videotapes covering 6,900 m2 of lake bed at depths of 23-41 m averaged 139 individuals/ hectare (range, 0-571/hectare). This density was substantially higher than the highest burbot density (59-95/hectare) reported in the literature. Burbot were present on the lake bed at depths of 23-36 m, but were most abundant near the crest of the reef at 23-28 m, where the water temperature was 8-13°C, their preferred summer temperature range. Substrates in that temperature range on the reef were bedrock, bedrock ridges, and bedrock and rubble. Burbot were most abundant on the bedrock and rubble. Small fish and macroinvertebrates typically eaten by burbot elsewhere in western Lake Michigan were distributed on the reef according to their summer preferred temperatures and were not seen in abundance where burbot density was highest. We saw no lake trout Salvelinus namaycush on Julian's Reef, although large numbers of juvenile lake trout have been stocked there annually and temperatures on the reef were in the preferred summer temperature range for lake trout.

  14. Distribution, abundance, and resting microhabitat of burbot on Julian's Reef, southwestern Lake Michigan

    USGS Publications Warehouse

    Edsall, Thomas A.; Kennedy, Gregory W.; Horns, William H.

    1993-01-01

    We used a remotely operated submersible vehicle equipped with a color video camera to videotape the lake bed and document the distribution and abundance of burbot Lota lotaon a 156-hectare portion of Julian's Reef in southwestern Lake Michigan. The substrates and bathymetry of the study area had been mapped recently by side-scan sonar. Burbot density determined from videotapes covering 6,900 m2 of lake bed at depths of 23–41 m averaged 139 individuals/ hectare (range, 0–571/hectare). This density was substantially higher than the highest burbot density (59–95/hectare) reported in the literature. Burbot were present on the lake bed at depths of 23–36 m, but were most abundant near the crest of the reef at 23–28 m, where the water temperature was 8–13°C, their preferred summer temperature range. Substrates in that temperature range on the reef were bedrock, bedrock ridges, and bedrock and rubble. Burbot were most abundant on the bedrock and rubble. Small fish and macroinvertebrates typically eaten by burbot elsewhere in western Lake Michigan were distributed on the reef according to their summer preferred temperatures and were not seen in abundance where burbot density was highest. We saw no lake trout Salvelinus namaycush on Julian's Reef, although large numbers of juvenile lake trout have been stocked there annually and temperatures on the reef were in the preferred summer temperature range for lake trout.

  15. Heavy-metal contamination of Crassostrea virginica and associated sediments of the Corpus Christi Bay system, Texas

    USGS Publications Warehouse

    Harrison, G.; Martin, E.A.

    1982-01-01

    In a preliminary survey, Crassostrea virginica from areas of the Corpus Christi Bay system of Texas show significant concentrations of Cd, Cu, Pb, and Zn in their tissues and shells; concentrations of these same metals in associated sediments are also high in certain areas of the bay system. Zn and Cd concentrations in tissue show a high negative correlation to each other, whereas Zn and Pb in tissue and shell show a high positive correlation to one another. Sediment contents of Pb and Zn best reflect tissue values of the heavy metals; sediment concentrations of Cd and Cu show a poor inverse correlation to tissue concentrations. Some possible factors influencing these correlations are suspended-sediment type, physiological changes, water quality, and Ca intake.

  16. Is Julian Assange an International Version of Daniel Ellsberg and WikiLeaks the Modern Equivalent of the Pentagon Papers?

    ERIC Educational Resources Information Center

    Freivogel, William H.

    2011-01-01

    History has placed the stamp of approval on the publication of the Pentagon Papers, the top-secret history of the Vietnam War. If WikiLeaks editor-in-chief Julian Assange is another Daniel Ellsberg, then it is possible the website's disclosures will be viewed over time as similarly in the public interest. A classroom discussion on the release of…

  17. Spontaneous onset of a Madden-Julian oscillation event in a cloud-system-resolving simulation

    NASA Astrophysics Data System (ADS)

    Miura, Hiroaki; Satoh, Masaki; Katsumata, Masaki

    2009-07-01

    Spontaneous onset of a Madden-Julian Oscillation (MJO) event in November 2006 was reproduced at a proper location and time by a global cloud-resolving model (CRM) used with a relatively coarse horizontal grid. Preconditioning of moisture was simulated about 4-days prior to the onset in the Indian Ocean, which agreed with data obtained in an in-situ observation. To investigate influence of zonal Sea Surface Temperature (SST) gradient in the Indian Ocean, we conducted a sensitivity study comparing composites made from five ensemble simulations. It was found that the eastward-moving signal of this MJO event could be obscured if SST were zonally uniform in the western Indian Ocean. Zonal SST gradient has not been considered important in the previous studies about the MJO onset, but SST distribution locating cooler SST in the west side possibly help enhance convection in slow eastward-moving envelopes of the MJO.

  18. Exploring the Madden Julian Oscillation through superparameterized global hindcasts during the Year of Tropical Convection

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

    The Superparameterized* (SP) Community Atmosphere Model (SPCAM) v. 3.0 has been shown to produce intriguingly realistic signatures of MJO variability in composited multidecadal simulations. Here, SPCAM is applied in intraseasonal forecast mode for the first time, to examine its skill in representing real-world Madden-Julian Oscillation (MJO) episodes highlighted by the Year of Tropical Convection. The phase-dependence of simulated forecast skill indicates that the SP-MJO may be a more valid physical analog for the initiating phases of the MJO than during other phases. Sensitivity tests reconfiguring the interior cloud model in three dimensions document the unexplored effect of incorporating convective momentum transport (CMT) on the SP-MJO. Some RMM skill benefits of incorporating CMT are evident at lead times of two weeks and greater. (* Superparameterization means embedding thousands of cloud resolving arrays in a global climate model, in place of conventional cumulus / boundary layer parameterizations.)

  19. Multiscale asymptotics for Madden-Julian Oscillations and Tropical-Extratropical Interactions

    NASA Astrophysics Data System (ADS)

    Chen, Shengqian; Majda, Andrew; Stechmann, Samuel

    2015-11-01

    A new model is derived and analyzed for tropical-extratropical interactions involving the Madden-Julian oscillation (MJO). The MJO has a time scale of 30-60 days and hence is important for extended-range forecasts on weekly to monthly time scales. The model combines (i) the tropical dynamics of the MJO and equatorial baroclinic waves and (ii) the dynamics of barotropic Rossby waves with significant extratropical structure, and the combined system has a conserved energy. The method of multiscale asymptotics is applied to systematically derive an ODE system for three-wave resonant interactions. Several examples illustrate applications to MJO initiation and termination, including cases of (i) the MJO, equatorial baroclinic Rossby waves, and barotropic Rossby waves interacting, and (ii) the MJO, baroclinic Kelvin waves, and barotropic Rossby waves interacting.

  20. Feature Tracking and Visualization of Madden-Julian Osciallation in Climate Simulation

    SciTech Connect

    Lee, Teng-Yok; Tong, Xin; Shen, Han-Wei; Wong, Pak C.; Hagos, Samson M.; Leung, Lai-Yung R.

    2013-06-20

    Madden-Julian Oscillation (MJO) is one of the less understood aspects of tropical meteorology, which plays a significant role in tropical intra-seasonal variations in rain, temperature and winds over the Indian and Pacific Oceans. In this paper, we present an integrated analysis and visualization framework for MJO episodes simulated by a high resolution regional model. To distinguish MJOs from other weather phenomena, our framework utilizes domain knowledge to track MJOs as finding the globally optimized properties in the data. In addition to enhancing the animation with feature tracking, our visualization system also integrates different visualization components such as Virtual Globe and Hovmoller Diagrams to visualize large scale events both in space and time. By linking all of these visualization components on a web-based interface, scientists can identify cloud and environmental processes associated with the initiation and eastward propagation of MJO more easily.

  1. Influence of Madden-Julian Oscillation on Southeast Asia rainfall extremes: Observations and predictability

    NASA Astrophysics Data System (ADS)

    Xavier, Prince; Rahmat, Raizan; Cheong, Wee Kiong; Wallace, Emily

    2014-06-01

    The influence of Madden-Julian Oscillation (MJO) on the rainfall distribution of Southeast Asia is studied using TRMM satellite-derived rainfall and rain gauge data. It is shown that convectively active (suppressed) phases of MJO can increase (decrease) the probability of extreme rain events over the land regions by about 30-50% (20-25%) during November-March season. The influence of MJO on localized rainfall extremes are also observed both in rainfall intensity and duration. The Met Office Global Seasonal forecasting system seasonal forecasting system is shown to reproduce the MJO influence on rainfall distribution well despite the model biases over land. Skills scores for forecasting 90th percentile extreme rainfall shows significant skills for convective phases. This study demonstrates the feasibility of deriving probabilistic forecasts of extreme rainfall at medium range.

  2. Modulation of the boreal wintertime Madden-Julian oscillation by the stratospheric quasi-biennial oscillation

    NASA Astrophysics Data System (ADS)

    Yoo, Changhyun; Son, Seok-Woo

    2016-02-01

    Madden-Julian oscillation (MJO), the dominant mode of intraseasonal variability in the tropical troposphere, has a significant impact on global weather and climate. Here we present that the year-to-year variation of the MJO activity shows significant changes with the quasi-biennial oscillation (QBO) in the tropical stratosphere. Specifically, the boreal winter MJO amplitude, evaluated by various metrics, is typically stronger than normal during the QBO easterly phase at 50 hPa and weaker than normal during the QBO westerly phase at 50 hPa. This relationship, which is possibly mediated by the QBO-related static stability and/or vertical wind shear changes in the tropical upper troposphere and lower stratosphere, is robust whether or not the activeness of the MJO or QBO is taken into account. This result suggests a new potential route from the stratosphere that regulates the organized tropical convection, helping to improve the prediction skill of the boreal winter MJO.

  3. Using AMIE data to study cloud processes within the Madden-Julian Oscillation

    SciTech Connect

    Houze, Robert A.

    2015-12-17

    This study uses AMIE data to show how the small clouds in the Madden-Julian Oscillation first organize into lines and other patterns, how they develop the first rainshowers, how those showers deposit cool air over the ocean surface, how this cool air spreads and triggers deeper convection, how the deep convection develops into mesoscale systems, how the mesoscale systems modify the heating profile through the depth of the troposphere, and how the development of the clouds responds to and interacts with large-scale waves circumnavigating the globe at upper levels, and how equatorial trapped waves at lower levels modulates the development of the cloud population. The techniques used to analyze the radar and sounding data collected in AMIE to achieve the above results are innovative, and to obtain more general results we have used regional modeling with a variety of cloud microphysical schemes in combination with the data analyses.

  4. Low-order stochastic model and "past-noise forecasting" of the Madden-Julian Oscillation

    NASA Astrophysics Data System (ADS)

    Kondrashov, D.; Chekroun, M. D.; Robertson, A. W.; Ghil, M.

    2013-10-01

    This paper presents a predictability study of the Madden-Julian Oscillation (MJO) that relies on combining empirical model reduction (EMR) with the "past-noise forecasting" (PNF) method. EMR is a data-driven methodology for constructing stochastic low-dimensional models that account for nonlinearity, seasonality and serial correlation in the estimated noise, while PNF constructs an ensemble of forecasts that accounts for interactions between (i) high-frequency variability (noise), estimated here by EMR, and (ii) the low-frequency mode of MJO, as captured by singular spectrum analysis (SSA). A key result is that—compared to an EMR ensemble driven by generic white noise—PNF is able to considerably improve prediction of MJO phase. When forecasts are initiated from weak MJO conditions, the useful skill is of up to 30 days. PNF also significantly improves MJO prediction skill for forecasts that start over the Indian Ocean.

  5. Disruptions of El Niño–Southern Oscillation teleconnections by the Madden–Julian Oscillation

    USGS Publications Warehouse

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

    2014-01-01

    The El Niño–Southern Oscillation (ENSO) is the leading mode of interannual variability, with global impacts on weather and climate that have seasonal predictability. Research on the link between interannual ENSO variability and the leading mode of intraseasonal variability, the Madden–Julian oscillation (MJO), has focused mainly on the role of MJO initiating or terminating ENSO. We use observational analysis and modeling to show that the MJO has an important simultaneous link to ENSO: strong MJO activity significantly weakens the atmospheric branch of ENSO. For weak MJO conditions relative to strong MJO conditions, the average magnitude of ENSO-associated tropical precipitation anomalies increases by 63%, and the strength of hemispheric teleconnections increases by 58%. Since the MJO has predictability beyond three weeks, the relationships shown here suggest that there may be subseasonal predictability of the ENSO teleconnections to continental circulation and precipitation.

  6. Interpreting the upper level structure of the Madden-Julian oscillation

    NASA Astrophysics Data System (ADS)

    Monteiro, Joy M.; Adames, Ángel F.; Wallace, John M.; Sukhatme, Jai S.

    2014-12-01

    The nonlinear response of a spherical shallow water model to an imposed heat source in the presence of realistic zonal mean zonal winds is investigated numerically. The solutions exhibit elongated, meridionally tilted ridges and troughs indicative of a poleward dispersion of wave activity. As the speed of the jets is increased, the equatorial Kelvin wave is unaffected but the global Rossby wave train coalesces to form a compact, amplified quadrupole structure that bears a striking resemblance to the observed upper level structure of the Madden-Julian oscillation. In the presence of strong subtropical westerly jets, the advection of planetary vorticity by the meridional flow and relative vorticity by the zonally averaged background flow conspire to create the distinctive quadrupole configuration of flanking Rossby waves.

  7. Assessing exposure to disinfection by-products in women of reproductive age living in Corpus Christi, Texas, and Cobb county, Georgia: descriptive results and methods.

    PubMed Central

    Lynberg, M; Nuckols, J R; Langlois, P; Ashley, D; Singer, P; Mendola, P; Wilkes, C; Krapfl, H; Miles, E; Speight, V; Lin, B; Small, L; Miles, A; Bonin, M; Zeitz, P; Tadkod, A; Henry, J; Forrester, M B

    2001-01-01

    We conducted a field study in Corpus Christi, Texas, and Cobb County, Georgia, to evaluate exposure measures for disinfection by-products, with special emphasis on trihalomethanes (THMs). Participants were mothers living in either geographic area who had given birth to healthy infants from June 1998 through May 1999. We assessed exposure by sampling blood and water and obtaining information about water use habits and tap water characteristics. Two 10-mL whole blood samples were collected from each participant before and immediately after her shower. Levels of individual THM species (chloroform, bromodichloromethane, dibromochloromethane, and bromoform) were measured in whole blood [parts per trillion (pptr)] and in water samples (parts per billion). In the Corpus Christi water samples, brominated compounds accounted for 71% of the total THM concentration by weight; in Cobb County, chloroform accounted for 88%. Significant differences in blood THM levels were observed between study locations. For example, the median baseline blood level of bromoform was 0.3 pptr and 3.5 pptr for participants in Cobb County and Corpus Christi, respectively (p = 0.0001). Differences were most striking in blood obtained after showering. For bromoform, the median blood levels were 0.5 pptr and 17 pptr for participants in Cobb County and Corpus Christi, respectively (p = 0.0001). These results suggest that blood levels of THM species vary substantially across populations, depending on both water quality characteristics and water use activities. Such variation has important implications for epidemiologic studies of the potential health effects of disinfection by-products. PMID:11445514

  8. Integrating Sensor Data and Informatics to Improve Understanding of Hypoxia in the WATERS Network Testbed at Corpus Christi Bay, Texas

    NASA Astrophysics Data System (ADS)

    Coopersmith, E.; Kulis, P.; Brouwer, A.; Montagna, P.; Hodges, B. R.; Minsker, B.; Maidment, D.

    2007-12-01

    The goal of the WATERS Network Testbed in Corpus Christi Bay (Texas) is to better understand hypoxia by creating a prototype Environmental Information System (EIS) that links field data collection, real-time modeling techniques, and cyberinfrastructure. In this paper, we explore the connection between the bay's bottom-water hypoxia and wind mixing by integrating several field data sets within a machine-learning model and exploring the mechanisms leading to the model results using an independent data set. K-nearest neighbor machine learning models applied to several long-term data sets indicate that wind velocities are instrumental in forecasting hypoxic events. Additionally, statistical analysis suggests that the impacts of wind vary spatially throughout the bay. Forecasting algorithms can be employed to predict not only the expected value of dissolved oxygen levels throughout the bay, but also the probability of observing hypolimnetic hypoxia. Prior values of dissolved oxygen, salinity, wind direction, wind velocity, and water temperature have been shown to play a meaningful role in influencing the DO value twenty-four hours hence. Visualizing spatial maps of expected means and variances not only illustrate potentially hypoxia regions, but areas where future sampling would be most beneficial as well. We use a short-term field data set to explore the possible mechanisms controlling the observed statistical trends in long-term data sets. Field data taken from July 2006 document a specific hypoxic episode that follows a high wind event. Analyses of temporal changes in the vertical water column support the suspected connections between wind, salinity, and hypoxia, and suggest some possible mechanisms for this connection. It is suspected that wind controls the sinking of heavy, saline water into the bottom of Corpus Christi Bay from Laguna Madre, a nearby shallower bay. This isolation of dense water from surface oxygen replenishment may be critical in hypoxia

  9. Mercury bioaccumulation and bioaccumulation factors for Everglades mosquitofish as related to sulfate: a re-analysis of Julian II (2013).

    PubMed

    Pollman, Curtis D; Axelrad, Donald M

    2014-11-01

    The Everglades, an ecosystem of international significance, has elevated biota mercury levels representing risk to human and wildlife consumers of fish. Given the critical role of sulfate in the methylation of mercury, and because there is a significant agricultural contribution, one potential means of reducing these mercury levels is reducing Everglades sulfate inputs. Julian II (Bull Environ Contam Toxicol 90:329-332, 2013) conducted regression modeling of the relationship between surface water sulfate concentrations and Gambusia spp. mercury bioconcentration factors across the major hydrologic subunits of the Everglades, and used those results to draw conclusions about the role of sulfate in the cycling of mercury in the Everglades. We however demonstrate a number of fundamental problems with the analysis, interpretation and conclusions. As a result, we strongly caution against using the results of Julian II (Bull Environ Contam Toxicol 90:329-332, 2013) to formulate management decisions regarding mitigation of the Everglades mercury problem. PMID:25260994

  10. Significance of organochlorine and heavy metal residues in wintering shorebirds at Corpus Christi, Texas, 1976-77

    USGS Publications Warehouse

    White, D.H.; King, K.A.; Prouty, R.M.

    1980-01-01

    Organochlorine and heavy metal residues were determined in 103 shorebirds of seven species collected at Corpus Christi, Texas, during the winter of 1976-77 to evaluate their potential effects on population survival, DDE and polychlorinated biphenyls (PCBs) were detected in most samples. Chlordane isomers, dieldrin, toxaphene, and heptachlor epoxide also occurred, but less frequently. In general, organochlorine residues were low in skinned carcasses. Geometric means on a wet weight basis ranged from 0.25 ppm to 4.76 ppm for DDE and from 0.67 ppm to 6.64 ppm for PCBs; residues of the other compounds averaged less than 1 ppm in all instances. Mercury, lead, arsenic and vanadium occurred in all shorebird livers, and selenium and cadmium were detected in all kidneys. Residues of these metals, except selenium, were low in most tissue samples. Selenium averages varied from 1.77 ppm to 5.62 ppm (wet weight) in kidneys; residues in this range may be sufficient to inhibit reproduction or to induce other forms of toxicity, especially at the higher levels.

  11. Dynamics of Large-Scale Convective Onset in the Madden-Julian Oscillation

    NASA Astrophysics Data System (ADS)

    Powell, Scott Wayne

    The role of large-scale circulation anomalies in the convective onset of the Madden-Julian Oscillation (MJO) over the Indian Ocean during the Dynamics of the Madden-Julian Oscillation (DYNAMO) field campaign, conducted Oct. 2011--Feb. 2012, is explained using radar and rawinsonde observations, reanalysis, and regional model simulations. Convective onset was characterized by two episodic and rapid increases in the vertical growth of the cumuliform cloud population over the Indian Ocean: First, the areal coverage of moderately deep (~5 km) convection increased; about 1 week later, the areal coverage of deep (up to the tropopause) convection increased rapidly. Deep tropospheric wavenumber 1 anomalies in zonal wind and vertical velocity circumnavigated the tropics repeatedly during DYNAMO. MJO convective onset occurred when the upward branch of this wavenumber 1 circulation arrived over the Indian Ocean because a reduction in large-scale subsidence cooled the troposphere and steepened the lapse rate below 500 hPa. This made the environment more conducive to development of moderately deep convection. The moderately deep convection moistened the environment during week-long transition periods by transporting moisture vertically from the boundary layer to the free troposphere and detraining it into the clear-air environment, particularly between 650--850 mb. Regional cloud-permitting model simulations of convection during MJO onsets reproduced the distinct transition periods. The modeling results confirmed that rapid cooling of the environment enhanced the areal coverage of, and thus total vertical transport of water within, moderately deep convection at the beginning of transition periods. Evaporation of cloud condensate via entrainment or dissipation of clouds was directly responsible for environmental moistening. Cooling of the climatologically stable layer between 700--850 mb was particularly important because it allowed a greater number of cumulus elements growing

  12. Sea Surface Temperature Coupling to Madden-Julian Oscillations over the Indonesian Maritime Continent

    NASA Astrophysics Data System (ADS)

    Napitu, A. M.; Gordon, A. L.; Pujiana, K.

    2014-12-01

    The intraseasonal SST characteristics within the Indonesian Seas and their responses to the Madden-Julian Oscillations [MJO] are examined through analyses of observed and reanalysis datasets. Intraseasonal variation accounts for about 30% of SST variability, with the strongest signature is observed in Banda and Timor seas. The MJO signature in SST is evident in the form of energy peak at 35-45 days, amplification during the Northwest Monsoon (boreal winter), and eastward propagation. SST responds to sea-air heat flux associated with MJO with net heat flux into the ocean (atmosphere) characterizing the suppressed (active) phase of MJO. The influence of MJO on Banda Sea SST is greatest during La Niña periods, which are favorable for deeper thermocline conditions, which diminish the role of ocean processes driving vertical heat transfer between subsurface and surface layers. Diminished influence of ocean processes results in dominance of surface heat fluxes associated with MJO in governing intraseasonal SST variability. During El Niño, the role of ocean processes is favorable to mediate heat transfer between lower and upper layer of the ocean surface as thermocline is shallower. The ocean component heat fluxes then compete with MJO forced heat fluxes in governing SST variability as indicated by less pronounced eastward propagation.

  13. Predictability of the Madden-Julian Oscillation index: seasonality and dependence on MJO phase

    NASA Astrophysics Data System (ADS)

    Oliver, Eric C. J.; Thompson, Keith R.

    2016-01-01

    We describe here a damped harmonic oscillator model for the Wheeler and Hendon (Mon Weather Rev 132(8):1917-1932, 2004) Madden-Julian Oscillation (MJO) index in order to gain new insights into the predictability of the MJO. Building on a tradition of idealized models, the model for the MJO state consists of a bivariate autoregressive process, equivalent to a finite difference approximation to a dynamical underdamped harmonic oscillator, as represented by a second order ordinary differential equation. The statistical properties of the model, namely the ensemble mean, ensemble variance, and within-ensemble correlation, are used to develop predictability time scales for canonical MJO events. We explore the model under both white noise and coloured noise forcing and the model parameters are estimated using maximum likelihood estimation, as a function of season and initial MJO event amplitude and phase. The model provides a significantly better fit using coloured noise forcing, which is equivalent to using a higher order model, indicating that the MJO index is not a simple order-1 coupled autoregressive process. Using the fitted model we map the predictability times scales for the mean, variance, and correlation as a function of initial MJO position in phase space. It is shown that the predictability time scales, and thus MJO predictability, vary as a function of MJO phase space and season which is a novel result for empirical models of the MJO. The result that MJO predictability varies with MJO state also has relevance for the interpretation of the Maritime Continent prediction barrier.

  14. Potential spawning habitat for lake trout on Julian's Reef, Lake Michigan

    USGS Publications Warehouse

    Edsall, Thomas A.; Kennedy, Gregory W.

    1996-01-01

    Julian's Reef is an historical spawning ground for lake trout (Salvelinus namaycush) in southwestern Lake Michigan. It is a designated lake trout refuge and is the focus of lake trout restoration efforts in Illinois waters of the lake. We studied the reef to determine its potential as spawning habitat for stocked lake trout. We used side-scan sonar and a remotely operated vehicle equipped with a video camera to survey and map 156 ha of lake bed on the southeast portion of the reef, where an earlier study revealed the presence of loose-rock substrate potentially suitable for use by spawning lake trout. Our survey showed that the substrate on the reef that most closely resembled that described in the literature as suitable for spawning by stocked lake trout in the Great Lakes was rubble patches with interstitial depths greater than 20 cm. These rubble patches occupied about 2 ha of the 13-ha expanse of bedrock and rubble substrate near the reef crest in the surveyed area. We estimated that these rubble patches, if fully used by spawning lake trout, could accommodate egg deposition by at least 1,300–3,300 2.7-kg females.

  15. The Madden-Julian Oscillation and its Impact on Northern Hemisphere Weather Predictability during Wintertime

    NASA Technical Reports Server (NTRS)

    Jones, Charles; Waliser, Duane E.; Lau, K. M.; Stern, W.

    2003-01-01

    The Madden-Julian Oscillation (MJO) is known as the dominant mode of tropical intraseasonal variability and has an important role in the coupled-atmosphere system. This study used twin numerical model experiments to investigate the influence of the MJO activity on weather predictability in the midlatitudes of the Northern Hemisphere during boreal winter. The National Aeronautics and Space Administration (NASA) Goddard laboratory for the Atmospheres (GLA) general circulation model was first used in a 10-yr simulation with fixed climatological SSTs to generate a validation data set as well as to select initial conditions for active MJO periods and Null cases. Two perturbation numerical experiments were performed for the 75 cases selected [(4 MJO phases + Null phase) _ 15 initial conditions in each]. For each alternative initial condition, the model was integrated for 90 days. Mean anomaly correlations in the midlatitudes of the Northern Hemisphere (2O deg N_60 deg.N) and standardized root-mean-square errors were computed to validate forecasts and control run. The analyses of 500-hPa geopotential height, 200-hPa Streamfunction and 850-hPa zonal wind component systematically show larger predictability during periods of active MJO as opposed to quiescent episodes of the oscillation.

  16. Atmosphere-ocean coupled processes in the Madden-Julian oscillation

    NASA Astrophysics Data System (ADS)

    DeMott, Charlotte A.; Klingaman, Nicholas P.; Woolnough, Steven J.

    2015-12-01

    The Madden-Julian oscillation (MJO) is a convectively coupled 30-70 day (intraseasonal) tropical atmospheric mode that drives variations in global weather but which is poorly simulated in most atmospheric general circulation models. Over the past two decades, field campaigns and modeling experiments have suggested that tropical atmosphere-ocean interactions may sustain or amplify the pattern of enhanced and suppressed atmospheric convection that defines the MJO and encourage its eastward propagation through the Indian and Pacific Oceans. New observations collected during the past decade have advanced our understanding of the ocean response to atmospheric MJO forcing and the resulting intraseasonal sea surface temperature fluctuations. Numerous modeling studies have revealed a considerable impact of the mean state on MJO ocean-atmosphere coupled processes, as well as the importance of resolving the diurnal cycle of atmosphere-upper ocean interactions. New diagnostic methods provide insight to atmospheric variability and physical processes associated with the MJO but offer limited insight on the role of ocean feedbacks. Consequently, uncertainty remains concerning the role of the ocean in MJO theory. Our understanding of how atmosphere-ocean coupled processes affect the MJO can be improved by collecting observations in poorly sampled regions of MJO activity, assessing oceanic and atmospheric drivers of surface fluxes, improving the representation of upper ocean mixing in coupled model simulations, designing model experiments that minimize mean state differences, and developing diagnostic tools to evaluate the nature and role of coupled ocean-atmosphere processes over the MJO cycle.

  17. The Onset of the Madden-Julian Oscillation Within an Aquaplanet Model

    NASA Technical Reports Server (NTRS)

    Colon, Edward; Lindesay, James; Suarez, Max

    1997-01-01

    A series of numerical experiments using a two-level atmospheric general circulation model (AGCM) were performed for the purpose of investigating the coupling between sea surface temperature (SST) profile and the onset of the Madden-Julian Oscillation (MJO). The AGCM was modified to run as an aquaplane with all seasonal forcing removed. SST distributions based on the New Global Sea-Ice and Sea Surface Temperature (GISST) Data Set for 1903-1994 were generated then modified to vary the north-south gradient and tropical temperatures. It was found that the MJO signal did not depend on the SST temperature gradients but rather on the absolute temperature of the equatorial region, EOF analysis revealed that the SST distribution which generated the strongest MJO signal produced a periodic fluctuation in velocity potential at the 250 millibar level with a phase speed of 15 m/s, and a periodicity of 30 days which falls within the shortest limit of observed oscillations. This distribution also possessed the coolest equatorial SSTs which suggests that increased stability in the atmosphere favors the occurrence of organized MJO propagation.

  18. Possible Influences of the Madden-Julian Oscillation on Global Fire

    NASA Astrophysics Data System (ADS)

    Zhang, Chidong; McKinney, Matthew; Lasslop, Gitta; Kreidenweis, Sonia

    2015-04-01

    Possible influences of the Madden-Julian Oscillation (MJO) on global wildfire are investigated. Glob fire potential and activities are measured by the Nesterov Index (NI), fire danger index (FDI), fire number (FN), and burned area (BA) from the output of a process-based fire regime model (SPITFIRE). The MJO is described using the Real-Time Multivariate MJO (RMM) index. Eight MJO phases defined by the RMM index correspond to different longitudinal locations of positive and negative anomalies in its rainfall as it propagates eastward from the Indian to Pacific Oceans. Phase 0 is defined as periods without MJO signals. Potential influences of the MJO on global fire are demonstrated as the differences of the four fire parameters between each of the eight MJO phases and phase 0. Statistically significant (at the 95% confidence level) differences are identified in various MJO phases in the following regions: tropical Africa, the Amazonia, Siberia, western Russia, and North America. Potential implications and caveats of these signals are discussed.

  19. Role of Longwave Cloud-Radiation Feedback in the Simulation of the Madden-Julian Oscillation

    NASA Technical Reports Server (NTRS)

    Kim, Daehyun; Ahn, Min-Seop; Kang, In-Sik; Del Genio, Anthony D.

    2015-01-01

    The role of the cloud-radiation interaction in the simulation of the Madden-Julian oscillation (MJO) is investigated. A special focus is on the enhancement of column-integrated diabatic heating due to the greenhouse effects of clouds and moisture in the region of anomalous convection. The degree of this enhancement, the greenhouse enhancement factor (GEF), is measured at different precipitation anomaly regimes as the negative ratio of anomalous outgoing longwave radiation to anomalous precipitation. Observations show that the GEF varies significantly with precipitation anomaly and with the MJO cycle. The greenhouse enhancement is greater in weak precipitation anomaly regimes and its effectiveness decreases monotonically with increasing precipitation anomaly. The GEF also amplifies locally when convection is strengthened in association with the MJO, especially in the weak precipitation anomaly regime (less than 5 mm day(exp -1)). A robust statistical relationship is found among CMIP5 climate model simulations between the GEF and the MJO simulation fidelity. Models that simulate a stronger MJO also simulate a greater GEF, especially in the weak precipitation anomaly regime (less than 5 mm day(exp -1)). Models with a greater GEF in the strong precipitation anomaly regime (greater than 30 mm day(-1)) represent a slightly slower MJO propagation speed. Many models that lack the MJO underestimate the GEF in general and in particular in the weak precipitation anomaly regime. The results herein highlight that the cloud-radiation interaction is a crucial process for climate models to correctly represent the MJO.

  20. Modification of a Madden-Julian Oscillation index and its applications

    NASA Astrophysics Data System (ADS)

    Anderson, Thomas

    The Madden-Julian Oscillation (MJO) is the dominant component of the intraseasonal atmospheric variability in the tropics. The MJO signal consists of deep convection and overturning atmospheric zonal circulations propagating slowly eastward along the equator. Wheeler and Hendon (2004) developed a method of extracting the MJO signal based on the two leading empirical orthogonal functions (EOFs) of the combined fields of near-equatorially averaged zonal wind at 850-hPa and 200-hPa as well as the observed outgoing long wave radiation (OLR). The length of this index in time is severely limited by the inclusion of the OLR data, as this time series only goes back to June 1974 and becomes a problem when trying to study the long-term aspects of the MJO. A modified index based on a combined EOF analysis of the 200-hPa and 850-hPazonal wind fields is developed and validated against Wheeler and Hendon's index. This allows the limitation of the relatively short OLR data set to be circumvented, as wind reanalysis data extends back farther in time, while keeping the benefit of a high MJO signal extraction through combined EOF analysis. As the results show, the new index yields nearly identical results to the older, more restrictive index. Therefore, the modified index is used to analyze the behavior of the MJO on time scales longer than the inter-annual, MJO- ENSO interaction and the ability of the Global Environmental Multiscale (GEM) model to represent the MJO.

  1. Contribution of tropical cyclone for the preconditioning of the Madden-Julian Oscillation during CINDY2011

    NASA Astrophysics Data System (ADS)

    Kubota, H.; Yoneyama, K.; Hamada, J.

    2012-12-01

    During the international field experiment "Cooperative Indian Ocean experiment on intraseasonal variability in the Year 2011 (CINDY2011)", three Madden-Julian Oscillation (MJO) were generated over the Indian Ocean. In this study, the preconditioning process of the third MJO is investigated. After the second active phase of MJO reached maritime continent in early December 2011, its eastward propagation became unclear. Different convections were activated over the maritime continent in mid-December and third MJO was generated in late December over the Indian Ocean. During the preconditioning stage of the third MJO, westward propagating disturbances were observed from Sumatera Island to the central Indian Ocean and moistened the atmosphere. Convections over the Sumatera Island were activated from December 15th when the moist air mass reached from South China Sea. The origin of the moist air mass was tropical cyclone which was formed in South China Sea in December 10th. The high moisture associated with tropical cyclone activated the convection over Sumatera Island, promoted westward propagating disturbances, and acted a favorable environment for the preconditioning of the MJO.

  2. Past- and present-day Madden-Julian Oscillation in CNRM-CM5

    NASA Astrophysics Data System (ADS)

    Song, Eun-Ji; Seo, Kyong-Hwan

    2016-04-01

    Madden-Julian Oscillation (MJO) in the past (nineteenth century) and present day (twentieth century) is examined using preindustrial and historical experiments of Centre National de Recherches Météorologiques-Coupled Models, version 5 (CNRM-CM5) in Coupled Model Intercomparison Project Phase 5 (CMIP5). The present-day MJO is stronger than the past MJO by 33% and it is ~10% more frequent. In particular, the MJO phases 4-7 signifying deep convection situated over the Maritime continent and western Pacific (WP) are considerably enhanced. These changes are due mainly to greenhouse gas forcing with little impact from nature forcing. Dynamical mechanisms for this change are investigated. A peculiar strengthening of MJO over WP comes from increased basic-state sea surface temperature (SST) over the Central Pacific (CP) and EP. The increase in precipitation over WP results from both the response to enhanced SST over CP and the inverted Walker circulation induced by the EP and CP SST increase. The latter causes a pair of anticyclonic Rossby waves straddling the equator, leading to moisture convergence over WP.

  3. Multidecadal variations in the modulation of Alaska wintertime air temperature by the Madden-Julian Oscillation

    NASA Astrophysics Data System (ADS)

    Oliver, Eric C. J.

    2015-07-01

    The Madden-Julian Oscillation (MJO), the dominant mode of intraseasonal variability in the tropics, is known to influence extratropical air temperature in the Northern Hemisphere. In particular, it has been shown that intraseasonal variations in wintertime Alaska surface air temperature (SAT) is linked with variations in cross-shore surface wind and that this mechanism is driven by a train of Rossby waves originating in the tropics due to MJO forcing. We show, using long station records of Alaska SAT and an independent reconstruction of the MJO index over the twentieth century, that the MJO-SAT connection in Alaska has undergone significant multidecadal variability over the last century. The Pacific Decadal Oscillation appears to explain some of the observed multidecadal variability but fails to capture a large proportion of it. We identify four distinct periods between the years 1910 and 2000 that exhibit either a weak, moderate or strong MJO-SAT connection. The nature of our method ensures that the detected multidecadal variability is due to changes in the teleconnection mechanism and not due to changes in the strength of the MJO index. Finally, we speculate on the mechanism which may bring about such multidecadal variations in the teleconnection mechanism.

  4. Essential-Oil Variability in Natural Populations of Pinus mugo Turra from the Julian Alps.

    PubMed

    Bojović, Srdjan; Jurc, Maja; Ristić, Mihailo; Popović, Zorica; Matić, Rada; Vidaković, Vera; Stefanović, Milena; Jurc, Dušan

    2016-02-01

    The composition and variability of the terpenes and their derivatives isolated from the needles of a representative pool of 114 adult trees originating from four natural populations of dwarf mountain pine (Pinus mugo Turra) from the Julian Alps were investigated by GC-FID and GC/MS analyses. In total, 54 of the 57 detected essential-oil components were identified. Among the different compound classes present in the essential oils, the chief constituents belonged to the monoterpenes, comprising an average content of 79.67% of the total oil composition (74.80% of monoterpene hydrocarbons and 4.87% of oxygenated monoterpenes). Sesquiterpenes were present in smaller amounts (average content of 19.02%), out of which 16.39% were sesquiterpene hydrocarbons and 2.62% oxygenated sesquiterpenes. The most abundant components in the needle essential oils were the monoterpenes δ-car-3-ene, β-phellandrene, α-pinene, β-myrcene, and β-pinene and the sesquiterpene β-caryophyllene. From the total data set of 57 detected compounds, 40 were selected for principal-component analysis (PCA), discriminant analysis (DA), and cluster analysis (CA). The overlap tendency of the four populations suggested by PCA, was as well observed by DA. CA also demonstrated similarity among the populations, which was the highest between Populations I and II. PMID:26880430

  5. The boreal winter Madden-Julian Oscillation's influence on summertime precipitation in the greater Caribbean

    NASA Astrophysics Data System (ADS)

    Curtis, Scott; Gamble, Douglas W.

    2016-07-01

    Precipitation totals in the greater Caribbean are known to be affected by interannual variability. In particular, dry conditions in the spring-summer have been physically linked to the positive phase of North Atlantic Oscillation (NAO) in the literature. In this study, it was found through regression analysis that an active Madden-Julian Oscillation (MJO) in winter geographically focused over the Maritime Continent contributes to a positive NAO in March via the generation of Rossby waves in the Northern Hemisphere. Specifically, a negative Pacific-North American pattern develops in the winter and transitions to an Atlantic pattern in spring. The positive NAO is a transient feature of this evolving wave train, but a center of significant positive 200 hPa geopotential heights is entrenched over the southeast U.S. throughout the February to May time period and is manifested as high pressure at the surface. The southern flank of this system increases the speeds of the trade winds and leads to a cooling of the Caribbean sea surface temperatures and, thus, convection suppression and reduced precipitation. Thus, this study advances our understanding of the climate of the greater Caribbean by using climate teleconnections to relate the MJO to rainfall in the region.

  6. Optimal Initial Perturbations for Ensemble Prediction of the Madden-Julian Oscillation during Boreal Winter

    NASA Technical Reports Server (NTRS)

    Ham, Yoo-Geun; Schubert, Siegfried; Chang, Yehui

    2012-01-01

    An initialization strategy, tailored to the prediction of the Madden-Julian oscillation (MJO), is evaluated using the Goddard Earth Observing System Model, version 5 (GEOS-5), coupled general circulation model (CGCM). The approach is based on the empirical singular vectors (ESVs) of a reduced-space statistically determined linear approximation of the full nonlinear CGCM. The initial ESV, extracted using 10 years (1990-99) of boreal winter hindcast data, has zonal wind anomalies over the western Indian Ocean, while the final ESV (at a forecast lead time of 10 days) reflects a propagation of the zonal wind anomalies to the east over the Maritime Continent an evolution that is characteristic of the MJO. A new set of ensemble hindcasts are produced for the boreal winter season from 1990 to 1999 in which the leading ESV provides the initial perturbations. The results are compared with those from a set of control hindcasts generated using random perturbations. It is shown that the ESV-based predictions have a systematically higher bivariate correlation skill in predicting the MJO compared to those using the random perturbations. Furthermore, the improvement in the skill depends on the phase of the MJO. The ESV is particularly effective in increasing the forecast skill during those phases of the MJO in which the control has low skill (with correlations increasing by as much as 0.2 at 20 25-day lead times), as well as during those times in which the MJO is weak.

  7. Modulation of Global Fire Probability by the Madden-Julian Oscillation

    NASA Astrophysics Data System (ADS)

    Zhang, Chidong

    2014-05-01

    The Madden-Julian Oscillation (MJO) is an atmospheric phenomenon that dominates the subseasonal (20 - 90 day) variability in the tropics. Its main feature includes an eastward moving large-scale center of deep convection from the Indian Ocean to the western and central Pacific Ocean. As its convection center moves eastward, the MJO exerts influences on many weather, climate and other phenomena in the Earth system, both in the tropics and extratropics. Satellite-based global fire data sets (MODIS, ATSR) have revealed that probability of fire in many regions of the world undergoes systematic changes through the life cycle of the MJO. For example, when MJO convection center is located over the Indian Ocean, fire probability is anomalous high in West Africa and northern Australia, but anomalously low in central Africa, the Amazonia, and Alaska. In the tropics, such changes are directly related to rainfall fluctuations of the MJO itself in the eastern hemisphere, and are consequences of atmospheric equatorial waves excited by MJO convection that propagate into the western hemisphere. In the extratropics, the changes are mainly due to teleconnection patterns in the atmosphere established by anomalous convection of the MJO. Simultaneous perturbations in rainfall, surface temperature and humidity suggest that no single meteorological variable can fully explain the modulation of fire probability by the MJO. Current efforts are being made to related wild fire to lightening frequencies, which are also modulated by the MJO.

  8. Future change in the Madden-Julian oscillation using CMIP5 simulations

    NASA Astrophysics Data System (ADS)

    Song, E. J.; Seo, K. H.; Lee, H. J.; Kim, G. U.

    2014-12-01

    Future changes in the Madden-Julian oscillation (MJO) have been examined using CMIP5 simulations. To represent future MJO change, historical experiment data from 1979 to 2005 and representative concentration pathway 8.5 (RCP 8.5) run data from 2071 to 2100 are compared. Several changes and associated processes are investigated: 1) MJO will strengthen. For this, the following three aspects are presented. First, in wavenumber-frequency power spectrum analysis for 30-90 days filtered precipitation over [15°S-15°N], spectral power tends to increase significantly. Second, the explained variance of combined EOF1 and EOF2 using 30-90 days filtered zonal winds at 200 and 850 hPa and OLR increases from 46% to 54%. Lastly, the days of MJO index (defined as the amplitude of PC1 and 2 in combined EOF) that is larger than 1.0 increase. 2) Changes in the MJO phase speed are unclear, because different models in CMIP5 show different results. The main process for controlling the phase speed of the MJO will be examined using two and half layer model. Other characteristics of the MJO will be discussed through the moist static energy and moisture budget analyses.

  9. Respective roles of shallow convection and stratiform rainfall on the simulation of Madden-Julian Oscillation.

    SciTech Connect

    Fu, Joshua Xiouhua [IPRC Wang, Bin [IPRC&DM Yeh, Hsi-Chyi

    2010-03-15

    Respective Roles of Shallow Convection and Stratiform Rainfall on the Simulation of Madden Julian Oscillation Joshua Xiouhua Fu IPRC, SOEST, University of Hawaii The IPRC/UH Hybrid-coupled GCM (HcGCM), which combined ECHAM-4 AGCM with UH intermediate ocean model, produces robust Tropical Intra-Seasonal Oscillations including the boreal-winter MJO and boreal-summer Monsoon Intra-Seasonal Oscillation. In this study, two sets of sensitivity experiments (i.e., short-term retrospective forecast of one MJO event observed during TOGA COARE and long-term free integrations) have been carried out to understand the respective roles of shallow-convection and stratiform rainfall on the simulations and predictions of the MJO. Major findings are summarized as following: Shallow-convection ahead of MJO deep convection moistens the lower-troposphere and preconditions the movement of the MJO. Present study shows that this process is very important to the eastward propagating speed of the MJO. A significant fraction of stratiform rainfall (~30%; stratiform part vs. total rainfall) is needed for ECHAM-4 to have a robust MJO. The above findings suggest that in addition to deep convection, shallow convection and stratiform rainfall needs to be well represented in conventional GCMs to ensure a robust model MJO.

  10. Global-scale convective aggregation: Implications for the Madden-Julian Oscillation

    NASA Astrophysics Data System (ADS)

    Arnold, Nathan P.; Randall, David A.

    2015-12-01

    Previous work has shown that convection will self-organize in cloud-system-resolving model simulations of radiative-convective equilibrium, and it has been suggested that the convective envelope of the Madden-Julian oscillation (MJO) may be organized by similar processes on a much larger scale. Here we present support for that hypothesis based on simulations with SP-CAM with globally uniform SST. Without rotation, convection self-organizes into large (˜4000 km) clusters surrounded by dry regions, while with Earth-like rotation the model produces a robust MJO. The nonrotating aggregation and MJO are found to have similar budgets of moist static energy, both being supported by diabatic feedbacks, particularly cloud-longwave interaction. Mechanism denial experiments show that longwave heating anomalies associated with high clouds are essential to the nonrotating aggregation, and amplify the MJO. Simulations using the conventional CAM show a weaker MJO and a much weaker tendency for nonrotating aggregation, and both MJO activity and aggregation intensity are found to increase with the entrainment rate in the deep convection parameterization.

  11. Detail isotopic stratigraphy of snowpack - case study from Julian Alps (Slovenia)

    NASA Astrophysics Data System (ADS)

    Vreča, P.; Brenčič, M.; Sinjur, I.; Sokratov, S.

    2012-04-01

    In temperate humid catchments the storage of precipitation in snowpack, and the subsequent melting, both highly variable in space and time, substantially impacts the water cycle. Recent climate warming and changes in atmospheric circulation patterns have resulted in reductions in the duration of the snow cover season, the amount of water stored in the snowpack, as well as a widespread trend toward earlier melt. Comparison of water balance for periods 1961-90 and 1971-2000 showed that in Slovenia average precipitation amount remained the same in both periods while runoff decreased and the evaporation increased recently. The area of Julian Alps (NW Slovenia) represents the upper catchment area of river Sava. The area is locally characterised as one with the highest annual precipitation amount in Europe, rapid runoffs and low evaporation. Snow cover is regular, starts to accumulate in late autumn and lasts more than 100 days, at the upper tree line usually more than 150 days. Due to positive air temperature trend snow cover period is changing and consequently the discharge regime is affected. Spatial and temporal variability of snow, as well as snow cover contribution to the water balance in Julian Alps remains poorly investigated. Isotopes of O and H have been used to study snow deposition and the subsequent alteration of snowpack and its influence on runoff. Despite their potential, environmental isotopes were only rarely used in investigations of water cycle in mountain areas of Slovenia in the past. To improve the knowledge on snowpack isotope characteristics and processes in it, and consequently to enable better understanding of water balance with emphasize on recharge of important Slovene aquifers, in 2011 at selected site in the area of Triglav National Park (Planina Javornik) the first isotope research of snowpack has been started. We performed detail sampling of snowpack at two locations with different canopy structures (e.g. clearing and forest stand

  12. Analysis of extreme rainfall in South America associated with Madden-Julian Oscillation

    NASA Astrophysics Data System (ADS)

    Leutwiler Silva, Elaine; Siqueira Silva, Maria Elisa

    2014-05-01

    Since the early Twentieth Century, the scientific community has recorded the observation of atmospheric and oceanic oscillations related to climatic behavior in remote areas with influence on intraseasonal, interannual and decadal scales, as indicated by [Walker, (1924); Bjerkness (1969); Gutzler and Wallace (1981); Rogers and Van Loon (1978, 1979)]. On the intraseasonal scale, Madden-Julian Oscillation (MJO) plays a key role in the modulation of rainfall in the tropics and subtropics (Kayano et al., 2009) being characterized by an east shift in a zonal large-scale and thermally direct cell on the Pacific Ocean. This oscillation was first detected in the work of Madden and Julian (1971, 1972) through the application of spectral analysis on daily radiosonde data provided by the National Center for Atmospheric Research (NCAR), for the stations at Canton island. The analysis allowed the detection and documentation of oscillations with periods from 40 to 50 days with strong associations between the surface pressure, zonal wind and temperature at different atmospheric levels. Although Souza and Ambrizzi (2006) indicate that South America (SA) has its convective activity altered due to the passage of the MJO, at the present moment, the existing models of climate prediction have not been able to correctly reproduce the propagation of the MJO. This study aims to analyze the periods of occurrence of extreme precipitation and drought in SA associated with OMJ and check the ability of Regional Circulation Model (RegCM4) to simulate this climate variability both diagnostically and prognostically. Daily rainfall data compiled by Liebmann and Allured (2005) will be used for the period 1978-2005 for the detection of MJO influence on SA precipitation. The analysis of atmospheric fields (wind at 200 and 850 hPa and omega at 500 and 850 hPa) of the Reanalysis I data set (Kalnay, 1996) obtained from the Physical Sciences Division (PSD) will be performed in order to verify the

  13. Influence of the Madden Julian Oscillation on precipitation and surface air temperature in South America

    NASA Astrophysics Data System (ADS)

    Alvarez, Mariano S.; Vera, C. S.; Kiladis, G. N.; Liebmann, B.

    2016-01-01

    The regional influence of the Madden-Julian oscillation (MJO) on South America is described. Maps of probability of weekly-averaged rainfall exceeding the upper tercile were computed for all seasons and related statistically with the phase of the MJO as characterized by the Wheeler-Hendon real-time multivariate MJO (RMM) index and with the OLR MJO Index. The accompanying surface air temperature and circulation anomalies were also calculated. The influence of the MJO on regional scales along with their marked seasonal variations was documented. During December-February when the South American monsoon system is active, chances of enhanced rainfall are observed in southeastern South America (SESA) region mainly during RMM phases 3 and 4, accompanied by cold anomalies in the extratropics, while enhanced rainfall in the South Atlantic Convergence Zone (SACZ) region is observed in phases 8 and 1. The SESA (SACZ) signal is characterized by upper-level convergence (divergence) over tropical South America and a cyclonic (anticyclonic) anomaly near the southern tip of the continent. Impacts during March-May are similar, but attenuated in the extratropics. Conversely, in June-November, reduced rainfall and cold anomalies are observed near the coast of the SACZ region during phases 4 and 5, favored by upper-level convergence over tropical South America and an anticyclonic anomaly over southern South America. In September-November, enhanced rainfall and upper-level divergence are observed in the SACZ region during phases 7 and 8. These signals are generated primarily through the propagation of Rossby wave energy generated in the region of anomalous heating associated with the MJO.

  14. Thermodynamics in the Suppressed Phase of the Madden-Julian Oscillation Using a Multiplatform Strategy

    NASA Technical Reports Server (NTRS)

    Roberts, J. Brent; Robertson, Franklin R.; Clayson, Carol Anne; Taylor, Patrick

    2014-01-01

    The Madden-Julian Oscillation (MJO) represents a prominent mode of intraseasonal tropical variability. It is manifest by coherent large-scale changes in atmospheric circulation, convection, and thermodynamic processes. Preconditioning of the environment prior to the active phase of the MJO has been noted, but the balance of theorized mechanisms to accomplish this process remains unresolved. Further, there is a lack of consensus on the means by which primary initiation of an MJO event occurs. Observational and modeling efforts have recently been undertaken to advance our understanding of the physical underpinnings governing MJO development. However these intensive studies are often limited in space and/or time and are potentially subject to model deficiencies. Satellite observations, especially those providing vertical resolution of temperature and moisture, provide an opportunity to expand our knowledge of processes critical to MJO initiation and preconditioning. This work will provide an analysis of suppressed phase thermodynamics with an emphasis on the use of a complementary suite of satellite observations including AIRS/AMSU-A profiles, CERES radiative fluxes, and cloud properties observed by MODIS. Emphasis of this work will regard the distribution of cloud regimes, their radiative-convective effects, and their relationship to moist static energy during the recharge and suppressed stages of MJO initiation and eastward propagation. The analyses will make use of cloud regimes from MODIS observations to provide a compositing technique that enables the identification of systematic connections between different cloud regimes and the larger scale environment. Within these cloud regimes, the relationship between the associated cloud-radiative effects observed by CERES, vertically-resolved and vertically-integrated thermodynamics using AIRS/AMSU-A observations, and atmospheric boundary layer fluxes will be demonstrated.

  15. Thermodynamics in the Suppressed Phase of the Madden-Julian Oscillation Using a Multiplatform Strategy

    NASA Astrophysics Data System (ADS)

    Roberts, J. B.; Robertson, F. R.; Clayson, C. A.; Taylor, P. C.

    2014-12-01

    The Madden-Julian Oscillation (MJO) represents a prominent mode of intraseasonal tropical variability. It is manifest by coherent large-scale changes in atmospheric circulation, convection, and thermodynamic processes. Preconditioning of the environment prior to the active phase of the MJO has been noted, but the balance of theorized mechanisms to accomplish this process remains unresolved. Further, there is a lack of consensus on the means by which primary initiation of an MJO event occurs. Observational and modeling efforts have recently been undertaken to advance our understanding of the physical underpinnings governing MJO development. However these intensive studies are often limited in space and/or time and are potentially subject to model deficiencies. Satellite observations, especially those providing vertical resolution of temperature and moisture, provide an opportunity to expand our knowledge of processes critical to MJO initiation and preconditioning. This work will provide an analysis of suppressed phase thermodynamics with an emphasis on the use of a complementary suite of satellite observations including AIRS/AMSU-A profiles, CERES radiative fluxes, and cloud properties observed by MODIS. Emphasis of this work will regard the distribution of cloud regimes, their radiative-convective effects, and their relationship to moist static energy during the recharge and suppressed stages of MJO initiation and eastward propagation. The analyses will make use of cloud regimes from MODIS observations to provide a compositing technique that enables the identification of systematic connections between different cloud regimes and the larger scale environment. Within these cloud regimes, the relationship between the associated cloud-radiative effects observed by CERES, vertically-resolved and vertically-integrated thermodynamics using AIRS/AMSU-A observations, and atmospheric boundary layer fluxes will be demonstrated.

  16. Realistic initiation and dynamics of the Madden-Julian Oscillation in a coarse resolution aquaplanet GCM

    NASA Astrophysics Data System (ADS)

    Ajayamohan, R. S.; Khouider, Boualem; Majda, Andrew J.

    2013-12-01

    The main mechanisms for the initiation and propagation of the Madden-Julian Oscillation (MJO) are still widely debated. The capacity of operational global climate models (GCMs) to correctly simulate the MJO is hindered by the inadequacy of the underlying cumulus parameterizations. Here we show that a coarse resolution GCM, coupled to a simple multicloud model parameterization mimicking the observed dynamics and physical structure of organized tropical convection, simulates the MJO in an idealized setting of an aquaplanet without ocean dynamics. We impose a fixed nonhomogeneous sea-surface temperature replicating the Indian Ocean/Western Pacific warm pool. This results in a succession of MJOs with realistic phase speed, amplitude, and physical structure. Each MJO event is initiated at a somewhat random location over the warm pool and dies sometimes near the eastern boundary of the warm pool and sometimes at a random location way beyond the warm pool. Also occasionally the MJO events stall at the center of maximum heating. This is reminiscent of the fact that in nature some MJOs stall over the maritime continent while others reach the central Pacific Ocean and beyond. The initiation mechanism in the model is believed to be a combination of persistent intermittent convective events interacting with observed large-scale flow patterns and internal tropical dynamics. The large-scale flow patterns are associated with planetary-scale dry Kelvin waves that are triggered by preceding MJO events and circle the globe, while congestus cloud decks on the flanks of the warm pool are believed to force Rossby gyres which then funnel moisture toward the equatorial region.

  17. A Multi-Scale Interaction Model for Madden-Julian Oscillation

    NASA Astrophysics Data System (ADS)

    Wang, B.; Liu, F.

    2010-12-01

    Madden-Julian oscillation (MJO) is an equatorial, planetary scale circulation system coupled with a multi-scale convective complex. The nature and roles of multi-scale interaction (MSI) on MJO dynamics has not been well understood. Here we formulate a prototype theoretical model to advance our understanding the MSI in MJO. The model integrates three essential elements: a) large scale equatorial wave dynamics driven by boundary layer frictional convergence instability (FCI), b) effects of multi-cloud heating and an instability arising from synoptic system-induced convective momentum transfer (CMT), and c) interaction between the planetary and synoptic systems. We show that the CMT mechanism tends to yield a growing stationary mode with a quadrupole-vortex horizontal structure (enhanced Rossby wave component); whereas the FCI favors a fast eastward-moving mode with a Gill-Pattern structure (enhanced Kelvin wave response). The MSI instability can stem from either FCI or CMT mechanisms or both, depending on the ratio of deep convective versus stratiform/congestus heating. With increasing stratiform/congestus heating, the FCI weakens while the CMT becomes more effective. A growing MSI mode has a mixed horizontal structure of CMT and FCI and prefers slow eastward propagation. The FCI sets the eastward propagation, and CMT plays a vital role in slowing down the propagation speed. These results encourage further observational diagnosis of multi-cloud structure and heating profiles in the MJO convective complex and improvement of models’ capability in reproducing correct partitioning of cloud amounts between deep convective and stratiform/congestus clouds.

  18. Analysis of rainfall characteristics of the Madden Julian oscillation using TRMM satellite data

    NASA Astrophysics Data System (ADS)

    Morita, Juntaro; Takayabu, Yukari N.; Shige, Shoichi; Kodama, Yasumasa

    2006-12-01

    Rainfall characteristics of the Madden-Julian oscillation (MJO) are analyzed primarily using tropical rainfall measuring mission (TRMM) precipitation radar (PR), TRMM microwave imager (TMI) and lighting imaging sensor (LIS) data. Latent heating structure is also examined using latent heating data estimated with the spectral latent heating (SLH) algorithm. The zonal structure, time evolution, and characteristic stages of the MJO precipitation system are described. Stratiform rain fraction increases with the cloud activity, and the amplitude of stratiform rain variation associated with the MJO is larger than that of convective rain by a factor of 1.7. Maximum peaks of both convective rain and stratiform rain precede the minimum peak of the outgoing longwave radiation (OLR) anomaly which is often used as a proxy for the MJO convection. Stratiform rain remains longer than convective rain until ˜4000 km behind the peak of the mature phase. The stratiform rain contribution results in the top-heavy heating profile of the MJO. Associated with the MJO, there are tri-pole convective rain top heights (RTH) at 10-11, ˜7 and ˜3 km, corresponding to the dominance of afternoon showers, organized systems, and shallow convections, respectively. The stratiform rain is basically organized with convective rain, having similar but slightly lower RTH and slightly lags the convective rain maximum. It is notable that relatively moderate (˜7 km) RTH is dominant in the mature phase of the MJO, while very tall rainfall with RTH over 10 km and lightning frequency increase in the suppressed phase. The rain-yield-per flash (RPF) varies about 20-100% of the mean value of ˜2-10 × 10 9 kg fl -1 over the tropical warm ocean and that of ˜2-5 × 10 9 kg fl -1 over the equatorial Islands, between the convectively suppressed phase and the active phase of MJO, in the manner that RPF is smaller in the suppressed phase and larger in the active phase.

  19. The effect of atmospheric radiative heating by clouds on the Madden-Julian Oscillation

    NASA Astrophysics Data System (ADS)

    Crueger, Traute; Stevens, Bjorn

    2015-06-01

    This article explores how atmospheric radiative heating, due to the presence of clouds, influences the Madden-Julian Oscillation (MJO) as simulated by four comprehensive atmosphere general circulation models. Simulations in which clouds are transparent to electromagnetic radiation ("clouds-off") are compared with control simulations in which clouds are allowed to interact with radiation ("clouds-on"). Making clouds transparent to radiation leads to robust changes of the mean state: the westerly winds in the equatorial Indo-Pacific area weaken and the precipitation reveals a shift from single to double Intertropical Convergence Zones. These changes are accompanied by weaker MJOs. Also, the moisture sensitivity of precipitation changes, however not consistently within our group of models. Further analyses show that within the active phase of intraseasonal variability, cloud-radiative effects amplify the heating profiles compared to clouds-off. Heating from nonradiative processes is dominated by the parameterized convection, but large-scale heating associated with cloud microphysical processes acting on the grid-scale modifies the shape of the heating profile, leading to a top-heaviness when cloud-radiative effects are accounted for. The radiative heating due to clouds slows down the phase speed of the MJO. Averaged over the entire MJO life cycle, the column-integrated radiative heating due to clouds lags the vertically integrated moist static energy by 40°-60° of longitude (equivalently 7-10 days assuming a period of 60 days). All four models studied reveal more pronounced Kelvin waves when clouds are transparent to radiation, suggesting that cloud-radiative effects on large-scale heating profiles damp smaller scale, or faster, Kelvin waves and amplify MJO-like disturbances.

  20. The impact of cloud radiative heating on the Madden-Julian Oscillation

    NASA Astrophysics Data System (ADS)

    Crueger, Traute; Stevens, Bjorn

    2015-04-01

    We explore how atmospheric radiative heating, due to the presence of clouds, influences the Madden-Julian-Oscillation (MJO) as simulated by four comprehensive atmosphere general circulation models. For that reason we compare simulations in which clouds are transparent to electromagnetic radiation ('clouds-off') with control simulations in which clouds are allowed to interact with radiation ('clouds-on"). Making clouds transparent to radiation leads to robust changes of the mean state and the MJO: tropical precipitation in the Indian ocean is displaced off the equator, leading to two symmetric bands of precipitation in this basin. In addition, in clouds-off, the MJO weakens compared to clouds-on. Within the MJO cloud radiative effects lead to stronger convective heating profiles. Heating from non-radiative processes is dominated by the parameterized convection, but large-scale heating associated with cloud microphysical processes acting on the grid-scale, modifies the shape of the profile, leading to a top-heaviness when cloud radiative effects are accounted for. The radiative heating due to clouds slows down the phase speed of the MJO. Averaged over the entire MJO life-cycle the column-integrated radiative heating due to clouds lags the vertically integrated moist static energy by 40° to 60° of longitude (equivalently 7 to 10 days assuming a period of 60 days). All four models studied reveal more pronounced Kelvin waves when clouds are transparent to radiation (clouds-off) suggesting that cloud-radiative effects on large-scale heating profiles acts to damp smaller scale, or faster, Convectively Coupled Equatorial Waves and amplify MJO-like disturbances.

  1. Links Between the Madden-Julian Oscillation and Severe Convective Storms in the U.S.

    NASA Astrophysics Data System (ADS)

    Barrett, B.

    2015-12-01

    Recent research has shown a tendency for severe convective storms to vary intraseasonally, including by phase of the Madden-Julian Oscillation (MJO). The MJO is the leading mode of atmospheric intraseasonal variability and is characterized by large regions (1000-5000 km) of anomalous convective activity that generally propagate eastward along the equator. Anomalous upper-troposphere heating associated with this convection generates poleward-propagating Rossby waves that interact with the preexisting extratropical circulation. The projection of this interaction onto the synoptic scale - via the favoring of troughs and ridges at certain positions - is the hypothesized mechanism by which the MJO modulates severe convection. However, one unexplored aspect of this modulation is the extent to which severe convection in winter and early-spring months, especially Jan-Mar, may be influenced by different phases of the MJO. While climatologically rarer than events later in spring, severe thunderstorms in winter and early spring still have potential to be high-impact weather events, especially as they often occur in populated areas of the southeast U.S. that have shown more vulnerability than other regions such as the southern or central plains. Results from other studies (not necessarily focused on the question of severe convective storms) have indicated statistically significant modulation of upper- and mid-tropospheric circulation (from 200 hPa to 700 hPa), surface temperature, and sea level pressure. Thus, it is possible that the MJO's influence also extends to severe storms, as these are ingredients known to affect the likelihood of convective activity in the U.S. Using a methodology similar to other recent MJO studies, the impacts of the MJO on tornado, hail, and wind activity from Jan-Mar will be tested as part of this larger project to understand intraseasonal variability of severe storms.

  2. Characteristics of Precipitation, Cloud, and Latent Heating Associated with the Madden-Julian Oscillation

    NASA Technical Reports Server (NTRS)

    Lau, K-M.; Wu, H-T.

    2010-01-01

    This study investigates the evolution of cloud and rainfall structures associated with Madden Julian oscillation (MJO) using Tropical Rainfall Measuring Mission (TRMM) data. Two complementary indices are used to define MJO phases. Joint probability distribution functions (PDFs) of cloud-top temperature and radar echo-top height are constructed for each of the eight MJO phases. The genesis stage of MJO convection over the western Pacific (phases 1 and 2) features a bottom-heavy PDF, characterized by abundant warm rain, low clouds, suppressed deep convection, and higher sea surface temperature (SST). As MJO convection develops (phases 3 and 4), a transition from the bottom-heavy to top-heavy PDF occurs. The latter is associated with the development of mixed-phase rain and middle-to-high clouds, coupled with rapid SST cooling. At the MJO convection peak (phase 5), a top-heavy PDF contributed by deep convection with mixed-phase and ice-phase rain and high echo-top heights (greater than 5 km) dominates. The decaying stage (phases 6 and 7) is characterized by suppressed SST, reduced total rain, increased contribution from stratiform rain, and increased nonraining high clouds. Phase 7, in particular, signals the beginning of a return to higher SST and increased warm rain. Phase 8 completes the MJO cycle, returning to a bottom-heavy PDF and SST conditions similar to phase 1. The structural changes in rain and clouds at different phases of MJO are consistent with corresponding changes in derived latent heating profiles, suggesting the importance of a diverse mix of warm, mixed-phase, and ice-phase rain associated with low-level, congestus, and high clouds in constituting the life cycle and the time scales of MJO.

  3. Prediction skill of the Madden and Julian Oscillation in dynamical extended range forecasts

    NASA Astrophysics Data System (ADS)

    Jones, C.; Waliser, D. E.; Schemm, J.-K. E.; Lau, W. K. M.

    The Madden and Julian Oscillation (MJO) is the most prominent mode of intraseasonal variations in the tropical region. It plays an important role in climate variability and has a significant influence on medium-to-extended ranges weather forecasting in the tropics. This study examines the forecast skill of the oscillation in a set of recent dynamical extended range forecasts (DERF) experiments performed by the National Centers for Environmental Prediction (NCEP). The present DERF experiments were done with the reanalysis version of the medium range forecast (MRF) model and include 50-day forecasts, initialized once-a-day (0Z) with reanalyses fields, for the period between 1 January, 1985, and 31 December, 1989. The MRF model shows large mean errors in representing intraseasonal variations of the large-scale circulation, especially over the equatorial eastern Pacific Ocean. A diagnostic analysis has considered the different phases of the MJO and the associated forecast skill of the MRF model. Anomaly correlations on the order of 0.3 to 0.4 indicate that skillful forecasts extend out to 5 to 7 days lead-time. Furthermore, the results show a slight increase in the forecast skill for periods when convective anomalies associated with the MJO are intense. By removing the mean errors, the analysis shows systematic errors in the representation of the MJO with weaker than observed upper level zonal circulations. The examination of the climate run of the MRF model shows the existence of an intraseasonal oscillation, although less intense (50-70%) and with faster (nearly twice as fast) eastward propagation than the observed MJO. The results indicate that the MRF model likely has difficulty maintaining the MJO, which impacts its forecast. A discussion of future work to improve the representation of the MJO in dynamical models and assess its prediction is presented.

  4. OP09STEREOTACTIC RADIOSURGERY FOR BRAIN METASTASES AT THE CHRISTIE AT SALFORD ROYAL HOSPITAL: OUR TWO-YEAR EXPERIENCE

    PubMed Central

    Helbrow, J.; McBain, C.; Gattamaneni, R.; Tran, A.; McCarthy, C.; Edwards, R.; Redikin, J.; Handley, J.; O'Hara, C.; Kennedy, J.; Mills, S.; Soh, C.; Leggate, J.; Whitfield, G.

    2014-01-01

    INTRODUCTION: Stereotactic radiosurgery (SRS) for brain metastases (BMs) commenced at The Christie at Salford in Dec 11 using the Novalis TxTM and BrainLab ExacTrac® system. We report our first 2 years' data. METHOD: Patients meeting NHS commissioning criteria were referred via MDT for assessment and if suitable consent. We used the BrainLab mask, CT and MRI. Gross tumour volumes (GTVs) were grown by 2mm if <4cm3 and by 1mm if >4cm3 to a planning target volume. The dose to the 80% isodose was 21Gy/1 fraction(#), 18Gy/1# and 25.5Gy/3# alternate days for PTVs <7cm3, 7-13cm3 and >13cm3 respectively and 30Gy/5# on alternate days to the 90% isodose in critical locations or where organ at risk constraints were exceeded. Follow up was 3-monthly with MRI and clinic review. Radiological response was classified as complete, unequivocal, enlargement consistent with treatment, enlargement suspicious of progression or unequivocal progression. RESULTS: Between Dec 11-Jan 14, 89 patients were consented, 51% female. Median age was 61 years (range 16-81). Primaries included lung (34%), breast (22%) and melanoma (15%), which was controlled in 67%; 42% had no extracranial metastases. A total of 170 BMs were treated (1 a retreat); per course a median of 2 (1-5) BMs were treated with median total GTV 4.87cm3 (0.05-29.9cm3). Prescribed dose was 21Gy/1# in 101 BMs, 18Gy/1# in 43, 25.5Gy/3# in 10 and 30Gy/5# in 16. One year survival from first SRS was: overall 48% (95% CI 34%-60%), lung 39% (18%-59%), breast 89% (62%-97%) and melanoma 44% (10%-75%). CONCLUSION: Overall survival results are encouraging and suggest appropriate patient selection. More detailed analysis including toxicity and time to intracranial progression will be presented.

  5. Precursor Environmental Conditions Associated with the Termination of Madden-Julian Oscillation Events

    NASA Astrophysics Data System (ADS)

    Stachnik, J. P.; Waliser, D. E.; Majda, A.

    2014-12-01

    Current generations of global climate models continue to struggle with simulating many of the observed features of the Madden-Julian oscillation (MJO) and suffer from low skill regarding initiation forecasts. While recent work has focused on those mechanisms thought to be important for MJO initiation, fewer studies have examined the large-scale conditions associated with quiescent periods of the MJO and the decay of existing events. Understanding these mechanisms may provide a valuable context toward improving simulations of MJO initiation and propagation in climate and operational weather forecast models. This study presents an analysis of the precursor environmental conditions related to the termination of MJO events. A simple climatology is created using a real-time MJO monitoring index, documenting the locations and frequencies of MJO decay. Lead-lag composites of several atmospheric variables including temperature, moisture, and intraseasonal wind anomalies are generated from three reanalyses. Long-term, lower tropospheric moisture deficits over the local domain best identify terminating events over the Indian Ocean, with a northward shift of the Intertropical Convergence Zone (ITCZ) and corresponding lead times as much as 20 days prior to MJO decay. Statistically significant differences are also identified more than 10 days in advance of MJO termination events in the west Pacific, though the vertical velocity and moisture anomalies are more symmetric about the equator. We also present results for those MJOs that terminate over the maritime continent. Unlike the Indian Ocean and west Pacific, the likelihood of an MJO to cross the maritime continent appears related to its own intensity, rather than the upstream environmental conditions, with only the strongest MJOs propagating into the warm pool region. Finally, a budget analysis is performed on the three-dimensional moisture advection equation in order to better elucidate what time-scales and physical

  6. The Madden-Julian oscillation in ECHAM4 coupled and uncoupled general circulation models

    DOE PAGESBeta

    Sperber, Kenneth R.; Gualdi, Silvio; Legutke, Stephanie; Gayler, Veronika

    2005-06-29

    The Madden-Julian oscillation (MJO) dominates tropical variability on timescales of 30–70 days. During the boreal winter/spring, it is manifested as an eastward propagating disturbance, with a strong convective signature over the eastern hemisphere. The space–time structure of the MJO is analyzed using simulations with the ECHAM4 atmospheric general circulation model run with observed monthly mean sea-surface temperatures (SSTs), and coupled to three different ocean models. The coherence of the eastward propagation of MJO convection is sensitive to the ocean model to which ECHAM4 is coupled. For ECHAM4/OPYC and ECHO-G, models for which ~100 years of daily data is available, Montemore » Carlo sampling indicates that their metrics of eastward propagation are different at the 1% significance level. The flux-adjusted coupled simulations, ECHAM4/OPYC and ECHO-G, maintain a more realistic mean-state, and have a more realistic MJO simulation than the nonadjusted scale interaction experiment (SINTEX) coupled runs. The SINTEX model exhibits a cold bias in Indian Ocean and tropical West Pacific Ocean sea-surface temperature of ~0.5°C. This cold bias affects the distribution of time-mean convection over the tropical eastern hemisphere. Furthermore, the eastward propagation of MJO convection in this model is not as coherent as in the two models that used flux adjustment or when compared to an integration of ECHAM4 with prescribed observed SST. This result suggests that simulating a realistic basic state is at least as important as air–sea interaction for organizing the MJO. While all of the coupled models simulate the warm (cold) SST anomalies that precede (succeed) the MJO convection, the interaction of the components of the net surface heat flux that lead to these anomalies are different over the Indian Ocean. The ECHAM4/OPYC model in which the atmospheric model is run at a horizontal resolution of T42, has eastward propagating zonal wind anomalies and latent heat

  7. The Madden-Julian Oscillation in ECHAM4 Coupled and Uncoupled GCMs

    SciTech Connect

    Sperber, K R; Gualdi, S; Legutke, S; Gayler, V

    2004-10-13

    The Madden-Julian Oscillation (MJO) dominates tropical variability on timescales of 30-70 days. During the boreal winter/spring it is manifested as an eastward propagating disturbance, with a strong convective signature over the eastern hemisphere. The space-time structure of the MJO is analyzed using simulations with the ECHAM4 atmospheric general circulation model run with observed monthly mean sea-surface temperatures, and coupled to three different ocean models. The coherence of the eastward propagation of MJO convection is sensitive to the ocean model to which ECHAM4 is coupled. For ECHAM4/OPYC and ECHO-G, models for which {approx}100 years of daily data is available, Monte Carlo sampling indicates that their metrics of eastward propagation are different at the 1% significance level. The flux-adjusted coupled simulations, ECHAM4/OPYC and ECHO-G, maintain a more realistic mean-state, and have a more realistic MJO simulation than the non-adjusted SINTEX coupled runs. The SINTEX model exhibits a cold bias in Indian Ocean and tropical West Pacific Ocean sea-surface temperature of {approx}0.5 C. This cold bias affects the distribution of time-mean convection over the tropical Eastern Hemisphere. Furthermore, the eastward propagation of MJO convection in this model is not as coherent as in the two models that used flux adjustment or compared to an integration of ECHAM4 with prescribed observed SST. This result suggests that simulating a realistic basic state is at least as important as air-sea interaction for organizing the MJO. While all of the coupled models simulate the warm (cold) SST anomalies that precede (succeed) the MJO convection, the interaction of the components of the net surface heat flux that lead to these anomalies are different over the Indian Ocean. The ECHAM4/OPYC model, in which the atmospheric model is run at a horizontal resolution of T42, has eastward propagating zonal wind anomalies and latent heat flux anomalies. However, the integrations

  8. The Madden-Julian oscillation in ECHAM4 coupled and uncoupled general circulation models

    SciTech Connect

    Sperber, Kenneth R.; Gualdi, Silvio; Legutke, Stephanie; Gayler, Veronika

    2005-06-29

    The Madden-Julian oscillation (MJO) dominates tropical variability on timescales of 30–70 days. During the boreal winter/spring, it is manifested as an eastward propagating disturbance, with a strong convective signature over the eastern hemisphere. The space–time structure of the MJO is analyzed using simulations with the ECHAM4 atmospheric general circulation model run with observed monthly mean sea-surface temperatures (SSTs), and coupled to three different ocean models. The coherence of the eastward propagation of MJO convection is sensitive to the ocean model to which ECHAM4 is coupled. For ECHAM4/OPYC and ECHO-G, models for which ~100 years of daily data is available, Monte Carlo sampling indicates that their metrics of eastward propagation are different at the 1% significance level. The flux-adjusted coupled simulations, ECHAM4/OPYC and ECHO-G, maintain a more realistic mean-state, and have a more realistic MJO simulation than the nonadjusted scale interaction experiment (SINTEX) coupled runs. The SINTEX model exhibits a cold bias in Indian Ocean and tropical West Pacific Ocean sea-surface temperature of ~0.5°C. This cold bias affects the distribution of time-mean convection over the tropical eastern hemisphere. Furthermore, the eastward propagation of MJO convection in this model is not as coherent as in the two models that used flux adjustment or when compared to an integration of ECHAM4 with prescribed observed SST. This result suggests that simulating a realistic basic state is at least as important as air–sea interaction for organizing the MJO. While all of the coupled models simulate the warm (cold) SST anomalies that precede (succeed) the MJO convection, the interaction of the components of the net surface heat flux that lead to these anomalies are different over the Indian Ocean. The ECHAM4/OPYC model in which the atmospheric model is run at a horizontal resolution of T42, has eastward propagating zonal wind anomalies and latent heat flux

  9. Assessment of Madden-Julian oscillation simulations with various configurations of CESM

    NASA Astrophysics Data System (ADS)

    Li, Xiaojing; Tang, Youmin; Zhou, Lei; Chen, Dake; Yao, Zhixiong; Islam, Siraj Ul

    2016-01-01

    This paper presents an assessment of the Madden-Julian oscillation (MJO) simulated in five experiments using the Community Earth System Model under different model settings. The analysis focused on the effects of air-sea coupling, resolution and atmospheric physics on the basic characteristics of the MJO, including intraseasonal variance, wavenumber-frequency characteristics and eastward propagation, using outgoing longwave radiation (OLR), zonal winds at 850 hPa (U850) and at 200 hPa (U200). Five experiments are conducted for this purpose including one atmospheric model—Community Atmosphere model version 4 (CAM4), two coupled models with CAM4 or Community Atmosphere model version 5 (CAM5) as the atmospheric component at a low resolution (CLP4_2d, CPL5_2d) and two the same coupled model with a high resolution (CPL4_1d and CLP5_1d). The results show that all models have better intraseasonal characteristics in U850 than in OLR. The uncoupled model CAM4 has lower fidelity than the coupled models in characterizing MJO basic features including the temporal and spatial intraseasonal variability and the eastward propagation. With ocean feedback, the coherence of convection and circulation is improved in the coupled models. The higher resolution is helpful in improving ISV spatial distribution and eliminating low frequency bias in the frequency-wavenumber spectra although it has little improvement to MJO-band variance (power) in frequency-wavenumber spectra. The new shallow convection scheme in CAM5 improves the moisture process of the lower troposphere so that CPL5_2d and CPL5_1d have more realistic eastward propagation speed in the boreal winter and better northward propagation in the boreal summer than other models. However, the strength of the convective MJO signal in CPL5_2d and CPL5_1d are weaker than other models and observations, which is probably one of the most spurious features in CPL5_2d and CPL5_1d experiments, suggesting that the CAM5 has a weaker

  10. Influence of Madden-Julian Oscillation (MJO) on Rainfall Variability over West Africa at Intraseasonal Timescale

    NASA Astrophysics Data System (ADS)

    Niang, C.

    2015-12-01

    Intraseasonal variability of rainfall over West Africa plays a significant role in the economy of the region and is highly linked to agriculture and water resources. This research study aims to investigate the relationship between Madden Julian Oscillation (MJO) and rainfall over West Africa during the boreal summer in the the state-of-the-art Atmospheric Model Intercomparison Project (AMIP) type simulations performed by Atmosphere General Circulation Models (GCMs) forced with prescribed Sea Surface Temperature (SST). It aims to determine the impact of MJO on rainfall and convection over West Africa and identify the dynamical processes which are involved in the state-of-the-art climate simulations. The simulations show in general good skills in capturing its main characteristics as well as its influence on rainfall over West Africa. On the global scale, most models simulated an eastward spatio-temporal propagation of enhanced and suppressed convection similar to the observed. However, over West Africa the MJO signal is weak in few of the models although there is a good coherence in the eastward propagation. The influence on rainfall is well captured in both Sahel and Guinea regions thereby adequately producing the transition between positive and negative rainfall anomalies through the different phases as seen in the observation. Furthermore, the results show that strong active convective phase is clearly associated with the African Easterly Jet (AEJ) but the weak convective phase is associated with a much weaker AEJ particularly over coastal Ghana. In assessing the mechanisms which are involved in the above impacts the convectively equatorial coupled waves (CCEW) are analysed separately. The analysis of the longitudinal propagation of zonal wind at 850hPa and outgoing longwave radiation (OLR) shows that the CCEW are very weak and their extention are very limited beyong West African region. It was found that the westward coupled equatorial Rossby waves are needed to

  11. Madden-Julian oscillation and sea surface temperature interactions in a multi-scale framework

    NASA Astrophysics Data System (ADS)

    Zhou, Lei

    2009-12-01

    The ocean-atmosphere coupling can play a role in initiating and sustaining the Madden-Julian Oscillations (MJOs), which are the major intraseasonal oscillations in the atmosphere. In this thesis, the oceanic influence on MJOs is studied with reanalysis products, numerical models, and idealized theoretical models. The energy sources for MJOs are calculated with NCEP reanalysis. The perturbed potential energy is found to be the most important energy source for most MJO events. In some MJO events, the sea surface is warmed due to the reduced latent heat flux during the suppressed phase of MJOs. As a result, warm sea surface temperature anomalies (SSTAs) occur, which appear to prolong the life time of these MJO events. In a minority of the MJO events, warm SSTAs can drive the atmosphere actively and trigger MJO events. In these events, the warm SSTAs are attributable to the internal oceanic processes influenced by the warm Indonesian Throughflow (ITF), which spreads from the southeastern Indian Ocean to the western Indian Ocean and modifies the subtle balance between stratification and mixing in the western Indian Ocean. In addition, during the transit period between monsoon seasons, a few MJO events are sustained by the energy obtained from the mean kinetic energy. Since the MJO events have different energy sources, their mechanisms should be considered in the context of these energy sources. While the spatial scale of the SSTAs in the Indian Ocean is only of order 100 km, the scale of MJOs is of order 1000 km, raising the potential for interactions between the oceanic and the atmospheric oscillations with different scales and this is demonstrated to be possible with analytical solutions to idealized linear governing equations. With a reasonable choice of parameters, the meso-scale oceanic and the large-scale atmospheric oscillations can interact with each other and lead to unstable waves in the intraseasonal band in this linear coupled model. The coupling and

  12. Vertical Structure and Physical Processes of the Madden-Julian Oscillation: A Model Evaluation Project

    NASA Astrophysics Data System (ADS)

    Woolnough, S. J.; Waliser, D. E.; Klingaman, N. P.; Jiang, X.; Petch, J.; Xavier, P. K.

    2014-12-01

    The fundamental physics of the generation, maintenance and propagation of the Madden-Julian Oscillation are intensely debated. Many theories focus on instabilities arising from interactions between components of the vertical diabatic heating from convection and the large-scale circulation. Most general circulation models (GCMs) exhibit biases in diabatic-heating profiles against observed or reanalysis products, but those products also exhibit considerable discrepancies with one another. The Vertical structure and physical processes of the MJO project is a novel model-evaluation project, designed to assess relationships between diabatic processes in GCMs and their representations of the MJO. A key advantage of the project is the acquisition of temperature, moisture and momentum tendencies from each of the model sub-grid physics schemes. The project has three components, designed to take advantage of known links between biases in short-range forecasts and climate simulations: (1) 20-year AMIP-type simulations to assess the representation of the MJO in each GCM; (2) 2-day hindcasts of two YoTC MJO events to investigate the timestep-level behaviour of physical parameterisations; (3) 20-day hindcasts of the same events to identify links between degradations in forecast skill and the representation of diabatic processes. Analysis of the three component has identified several over-arching conclusions. First, many process-oriented MJO diagnostics derived from past studies using one or several GCMs fail to distinguish between the GCMs in this project that simulate the MJO well and those that do so poorly, whether for initialised hindcasts or 20-year simulations. Second, there is little correlation between GCM hindcast skill for these cases and the fidelity of the MJO representation in climate simulations. Third, all three components have demonstrated that a reliable representation of the moistening profile, particularly lower- and mid-tropospheric moistening during the

  13. A Momentum Budget Analysis of Westerly Wind Events Associated with the Madden-Julian Oscillation during DYNAMO

    NASA Astrophysics Data System (ADS)

    Oh, Ji-Hyun; Jiang, Xianan; Waliser, Duane; Moncrieff, Mitchell; Johnson, Richard; Ciesielski, Paul

    2016-04-01

    Three Madden-Julian Oscillation events during Dynamics of the Madden-Julian Oscillation (DYNAMO) field campaign were investigated to understand the contributions of the dynamical processes involved in the wind evolution associated with the MJO over the Indian Ocean (IO). The DYNAMO field campaign was conducted from October 2011 to February 2012 over the IO to shed light on the initiation of the MJO. Based on European Centre for Medium-Range Weather Forecasts analysis, a momentum budget analysis of three MJOs that occurred in late October, late November, and late December shows that westerly acceleration at lower levels associated with the MJO active phase generally appears to be maintained by the pressure gradient force (PGF), which could be partly canceled by meridional advection of the zonal wind. Westerly acceleration in the midtroposphere tends to be mostly attributable to vertical advection. In particular, the dynamical contribution of synoptic-scale equatorial waves to the WWEs is illuminated by diagnosing the MJO in November (MJO2), accompanied by two WWEs (WWE1 and WWE2) spaced a few days apart. Unlike other WWEs during DYNAMO, horizontal advection is more responsible for the westerly acceleration in the lower troposphere for WWE2 than the PGF. Different interactions between the MJO2 envelope and convectively coupled waves (CCWs) can be responsible for different developing processes among WWEs.

  14. Geometry of the Paleo-Nueces River Incised-Valley, Corpus Christi Bay, Texas as it Relates to Quaternary Sea Level History

    NASA Astrophysics Data System (ADS)

    Lugrin, L.; Gulick, S. S.; Goff, J. A.

    2012-12-01

    CHIRP subbottom seismic data were collected on the 2009 and 2011 Marine Geophysics Field courses at the University of Texas at Austin within the Corpus Christi Bay along the central Texas coast in order to study the geometry of the ancestral Nueces River incised valley and its evolution over Quaternary sea level history. Since the late Pleistocene, the Nueces River valley experienced a gradual infill due to sea level rise, interrupted by two major flooding events that represent periods of rapid sediment influx. These flooding events are recognizable based on abrupt changes in seismic facies. Discontinuous, chaotic fluvial lag deposits present underneath a fairly continuous, stratified, sub-horizontal estuarine coastal plain facies mark what is interpreted to be the Pleistocene/Holocene unconformity. Above the P/H boundary, oyster reefs thrive within the estuary until capped by a strong reflector, marking the second flooding surface that allowed enough incoming sediment to discontinue oyster reef growth. The estuarine deposits within the paleo-Nueces river valley exhibit a landward migration as the Holocene transgression proceeded. As infill continued, the bay-head delta prograded seaward and the flood-tidal delta extended progressively further up the estuary until the central estuarine basin was capped. The earlier flooding events provide strong reflectors that can be linked to the draining of Lake Agassiz around 8.2 k.a.. This event flooded the Gulf of Mexico with freshwater, and interrupted the estuarine infilling of the Nueces paleo-channel. Cores from previous studies have found at least two species of oyster reefs in Corpus Christi Bay: euryhaline species Crassostrea virginica, and Ostrea equestris, a species known to thrive in higher salinity waters. The presence of both species at the flooding boundary suggests the sudden pulse of freshwater mixed with higher salinity oceanic water. The second flooding surface is interpreted to be associated with an increase

  15. Delineation of marsh types of the Texas coast from Corpus Christi Bay to the Sabine River in 2010

    USGS Publications Warehouse

    Enwright, Nicholas M.; Hartley, Stephen B.; Brasher, Michael G.; Visser, Jenneke M.; Mitchell, Michael K.; Ballard, Bart M.; Parr, Mark W.; Couvillion, Brady R.; Wilson, Barry C.

    2014-01-01

    Coastal zone managers and researchers often require detailed information regarding emergent marsh vegetation types for modeling habitat capacities and needs of marsh-reliant wildlife (such as waterfowl and alligator). Detailed information on the extent and distribution of marsh vegetation zones throughout the Texas coast has been historically unavailable. In response, the U.S. Geological Survey, in cooperation and collaboration with the U.S. Fish and Wildlife Service via the Gulf Coast Joint Venture, Texas A&M University-Kingsville, the University of Louisiana-Lafayette, and Ducks Unlimited, Inc., has produced a classification of marsh vegetation types along the middle and upper Texas coast from Corpus Christi Bay to the Sabine River. This study incorporates approximately 1,000 ground reference locations collected via helicopter surveys in coastal marsh areas and about 2,000 supplemental locations from fresh marsh, water, and “other” (that is, nonmarsh) areas. About two-thirds of these data were used for training, and about one-third were used for assessing accuracy. Decision-tree analyses using Rulequest See5 were used to classify emergent marsh vegetation types by using these data, multitemporal satellite-based multispectral imagery from 2009 to 2011, a bare-earth digital elevation model (DEM) based on airborne light detection and ranging (lidar), alternative contemporary land cover classifications, and other spatially explicit variables believed to be important for delineating the extent and distribution of marsh vegetation communities. Image objects were generated from segmentation of high-resolution airborne imagery acquired in 2010 and were used to refine the classification. The classification is dated 2010 because the year is both the midpoint of the multitemporal satellite-based imagery (2009–11) classified and the date of the high-resolution airborne imagery that was used to develop image objects. Overall accuracy corrected for bias (accuracy

  16. Impact of Sea Level Rise on the Attenuation of Hurricane Storm Surge by Wetlands in Corpus Christi, TX

    NASA Astrophysics Data System (ADS)

    Ferreira, C.; Irish, J. L.; Olivera, F.

    2011-12-01

    Celso Ferreira1, Jennifer L. Irish2, Francisco Olivera3 1 Graduate Research Assistant, Department of Civil Engineering, Texas A&M University, College Station, TX 77843, email: celsoferreira@tamu.edu. 2 Associate Professor, Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA 24061, email: jirish@vt.edu 3 Associate Professor, Department of Civil Engineering, Texas A&M University, College Station, TX 77843, email: folivera@civil.tamu.edu. Texas has historically faced severe hurricanes with Ike being the most recent major storm example. It is believed that coastal wetlands might reduce the impact of the storm surge on coastal areas, acting as a natural protection against hurricane flooding, especially for small hurricanes and tropical storms. Considering the expected rise in the mean sea level, wetland composition and spatial distribution are also expected to change as the environmental conditions change along the coast. We analyzed a range of Intergovernmental Panel on Climate Change (IPCC) projections for sea level rise (SLR) to simulate wetland alterations and evaluate their impact on hurricane storm surge. The analyses was conducted for Corpus Christi Bay using a pre-validated, physically based, hydrodynamic model (ADCIRC) and a wind and pressure field model (PBL) representing the physical properties of historical hurricane Bret. The calculations were performed using an unstructured numerical grid with 3.3 million nodes covering part of the Atlantic Ocean and the entire Gulf of Mexico (resolution from 2000 km to 50 meters at the coast). Wetlands are represented in the numerical model through their influence on the frictional resistance proprieties and bathymetric changes. To characterize the wetland types and their spatial distribution along the coast, we used six different land use databases from the National Land Cover Dataset (NLCD) (1992, 2001), the National Wetlands Inventory (NWI) (1993) and the Coastal Change Analysis Program (C

  17. Madden Julian Oscillation impact on South America precipitation and its associated teleconnections

    NASA Astrophysics Data System (ADS)

    Grimm, A. M.

    2013-12-01

    The anomalies in daily precipitation and in the frequency of its extreme events associated with the different phases of the Madden Julian Oscillation (MJO) are calculated with unprecedented temporal and spatial coverage for South America. These anomalies are shown to be produced by tropics-tropics and tropics-extratropics teleconnections. Besides, teleconnections are detected between intraseasonal precipitation anomalies in South America and southern Africa. The observational analysis of the MJO impact is based on daily precipitation station data over South America in the period 1979-2009, gridded to 1 degree, and submitted to a bandpass Lanczos filter, which retains intraseasonal oscillations in the 20-90 day band. The main modes of rainfall variability in this time scale are consistent with the anomalies during the different phases of the MJO, which are determined through indices based on the first two empirical orthogonal functions of the combined fields of zonal wind at 850 hPa and 200 hPa and OLR, between 15S e 15N, after removal of the annual cycle and interannual variability. Composites of anomalies in precipitation and in the frequency of extreme events are made for each phase, and their significance is assessed. The associated composites of global streamfunction, velocity potential and OLR anomalies give insights on the mechanisms of the impact. Teleconnections responsible for the impact are searched with the help of influence functions (IFs) of a vorticity equation model that includes the divergence of the basic state and the advection by anomalous divergent wind. The IFs are calculated for the action centers of wavetrains associated with the highest impact on South America, and indicate the regions in which upper level anomalous divergence associated with anomalous tropical convection is most efficient in producing the observed wavetrains. These source regions contain significant MJO-related OLR anomalies in the central subtropical southern Pacific

  18. Precipitation microstructure in different Madden-Julian Oscillation phases over Sumatra

    NASA Astrophysics Data System (ADS)

    Marzuki; Hashiguchi, Hiroyuki; Kozu, Toshiaki; Shimomai, Toyoshi; Shibagaki, Yoshiaki; Takahashi, Yukihiro

    2016-02-01

    Intraseasonal variations of precipitation and its microstructure are investigated using measurements of the Equatorial Atmospheric Radar (EAR) facilities at Kototabang, west Sumatra, Indonesia (0.20°S, 100.32°E, 864 m above sea level). Raindrop size distribution (DSD) observations are obtained from a 2D-Video Disdrometer (2DVD) with a near continuous record of operation over eight consecutive years (2003-2010). Precipitation types are classified using 1.3-GHz wind profiler observation, and are partitioned according to active and inactive convective phases of Madden-Julian Oscillation (MJO). It is found that precipitation systems during the inactive phase are more continental in nature than those during the active phase. Cloud propagation from brightness temperature data indicates that Sumatra receives the rainfall mainly from maritime clouds during the active phase, while it is mainly from the continental clouds (land-based convection) during the inactive phase. Other remarkable differences between active and inactive phase precipitation systems are also observed from the vertical structure of precipitation. The precipitation during the inactive phase has deeper storms, a higher reflectivity aloft, more lightning activity and less stratiform characteristics, as compared to the active phase. Assessment of cloud effective radius of the Moderate Resolution Imaging Spectroradiometer (MODIS) data also shows a slight difference in the cloud droplet between the active and the inactive MJO phases. Different convective storms in different MJO phases lead to different DSD characteristics and Z-R relationships. The DSD during the inactive phase tends to have a higher concentration of medium and large-size drops than the active counterpart, consistent with the previous study during the first campaign of Coupling Processes in the Equatorial Atmosphere project. Although the DSD parameters and coefficient of Z-R relationships fall within the range of tropical maritime

  19. A Smart ALEC Threatens Public Education

    ERIC Educational Resources Information Center

    Underwood, Julie; Mead, Julie F.

    2012-01-01

    Public education has historically been in the public and political eye. Then came 2011 and the high profile and well televised protests in Wisconsin, Ohio and Indiana. In each case Republican Governors and Republican controlled state legislatures had introduced substantially similar bills that sought sweeping changes to each state's collective…

  20. Walter Max Dale (formerly Deutsch) (1894-1969): pioneer and eminent radiobiochemist at the Christie Hospital and Holt Radium Institute, Manchester.

    PubMed

    Shreeve, David R

    2010-05-01

    The political upheaval in Germany in 1933 and subsequent movement of medical scholars with the support of the Rockefeller Foundation allowed Manchester to benefit from the arrival of Dr Walter Deutsch, later known as Dr Walter Dale. His research background enabled him to develop a radiobiochemistry laboratory at the Christie Hospital and Holt Radium Institute where he became a world authority on the effects of X-rays on enzymes and also the protective effect of additional solutes. In 1959 he initiated and then edited the International Journal of Radiation Biology. By the time of his retirement in 1962 the strength of his research resulted in his laboratory being recognized by the Medical Research Council. PMID:20519710

  1. Interannual variability of the Madden-Julian Oscillation and its impact on the North Atlantic Oscillation in the boreal winter

    NASA Astrophysics Data System (ADS)

    Lin, Hai; Brunet, Gilbert; Yu, Bin

    2015-07-01

    Interannual variability of the Madden-Julian Oscillation (MJO) and its influence on the extratropical teleconnection are analyzed. It is found that there is an interannual shift of the MJO activity between the Indian Ocean and the western central Pacific. This is reflected by the year-to-year changes in the occurrence frequency of individual MJO phases. The leading mode of an empirical orthogonal function analysis of occurrence frequency of MJO phases shows an out-of-phase relationship between MJO phase 7 and phases 3-5. During winters when the MJO convection occurs more frequently in the Indian Ocean (phases 3-5), a winter mean positive North Atlantic Oscillation (NAO) tends to occur. These results indicate that the seasonal mean convection activity over the Indian Ocean related to the MJO is a possible driving forcing for the seasonal mean NAO variability in the boreal winter.

  2. Surprising Resilience of the Madden-Julian Oscillation to Extreme Climate Cooling in the Superparameterized Community Atmosphere Model.

    NASA Astrophysics Data System (ADS)

    Pritchard, M. S.; Yang, D.

    2014-12-01

    We test the hypothesis that radiative convective equilibrium (RCE) self-aggregation is a good metaphor for the maintenance of the Madden-Julian Oscillation by imposing extreme cooling in the Superparameterized Community Atmosphere Model (SPCAM) v. 3.0 in a uniform SST configuration. The expectation is that - like RCE self-aggregation - SPCAM's simulated MJO should shut down at sea surface temperatures significantly less than 25 degrees Celsius. Remarkably, the MJO in SPCAM is resilient to extreme cooling down to one degree Celsius. With cooling, the simulated MJO becomes more barotropic and its zonal wavelength decreases. The amplitude decrease and horizontal scale contraction are consistent with the theoretical prediction from Yang and Ingersoll (2014, GRL).

  3. A mechanism-denial study on the Madden-Julian Oscillation with reduced interference from mean state changes

    NASA Astrophysics Data System (ADS)

    Ma, D.; Kuang, Z.

    2016-03-01

    Mechanism-denial experiments using Superparameterized Community Atmosphere Model are conducted to investigate the importance of extratropical and circumnavigating waves, wind-evaporation feedback, and radiative-convective feedback to the Madden-Julian Oscillation (MJO). A common issue with mechanism-denial studies is the interference from mean state changes when processes are turned off in the model. Here time-invariant forcing and nudging on effective timescales longer than the intraseasonal timescale are implemented to maintain the mean state. The MJO activity remains largely unchanged with suppressed extratropical and circumnavigating waves when the mean state is maintained to be close to that of the control run, suggesting that excitation of MJO by extratropical and circumnavigating waves is not necessary for the existence of MJO in this model. It is also shown that the wind-evaporation feedback slows down eastward propagation of the MJO, and the radiative-convective feedback amplifies the MJO.

  4. The Madden-Julian oscillation wind-convection coupling and the role of moisture processes in the MM5 model

    NASA Astrophysics Data System (ADS)

    Monier, Erwan; Weare, Bryan C.; Gustafson, William I.

    2010-08-01

    The Madden-Julian oscillation (MJO) produced by a mesoscale model is investigated using standardized statistical diagnostics. Results show that upper- and lower-level zonal winds display the correct MJO structure, phase speed (8 m s-1) and space-time power spectrum. However, the simulated free atmosphere moisture, outgoing longwave radiation and precipitation do not exhibit any clear MJO signal. Yet, the boundary layer moisture, moist static energy and atmospheric instability, measured using a moist static energy instability index, have clear MJO signals. A significant finding is the ability of the model to simulate a realistic MJO phase speed in the winds without reproducing the MJO wind-convection coupling or a realistic propagation in the free atmosphere water vapor. This study suggests that the convergence of boundary layer moisture and the discharge and recharge of the moist static energy and atmospheric instability may be responsible for controlling the speed of propagation of the MJO circulation.

  5. The Madden-Julian oscillation wind-convection coupling and the role of moisture processes in the MM5 model

    NASA Astrophysics Data System (ADS)

    Monier, E.; Weare, B. C.; Gustafson, W. I.

    2009-12-01

    The Madden-Julian oscillation (MJO) produced by a mesoscale model is investigated using standardized statistical diagnostics. Results show that upper- and lower-level zonal winds display the correct MJO structure, phase speed (8 m/s) and space-time power spectrum. However, the simulated free atmosphere moisture, outgoing longwave radiation and precipitation do not exhibit any clear MJO signal. Yet, the boundary layer moisture, moist static energy and atmospheric instability, measured using a moist static energy instability index, have clear MJO signals. A significant finding is the ability of the model to simulate a realistic MJO phase speed in the winds without reproducing the MJO wind-convection coupling or a realistic propagation in the free atmosphere water vapor. This study suggests that the convergence of boundary layer moisture and the discharge and recharge of the moist static energy and atmospheric instability may be responsible for controlling the speed of propagation of the MJO circulation.

  6. Advection, Moistening, and Shallow-to-deep Convection Transitions During the Initiation and Propagation of Madden-Julian Oscillation

    SciTech Connect

    Hagos, Samson M.; Feng, Zhe; Landu, Kiranmayi; Long, Charles N.

    2014-09-11

    Using observations from the 2011 AMIE/DYNAMO field campaign over the Indian Ocean and a high-resolution regional model simulation, the processes that lead to the rapid shallow-to-deep convection transitions associated with the initiation and eastward propagation of the Madden-Julian Oscillation (MJO) are examined. By tracking the evolution of the depth of several thousand individual model simulated precipitation features, the role of and the processes that control the observed midtropospheric moisture buildup ahead of the detection of deep convection are quantified at large and convection scales. The frequency of shallow-to-deep convection transitions is found to be sensitive to this midlevel moisture and large-scale uplift. This uplift along with the decline of large-scale drying by equator-ward advection causes the moisture buildup leading to the initiation of the MJO. Convection scale moisture variability and uplift, and large-scale zonal advection play secondary roles.

  7. On the role of anomalous ocean surface temperatures for promoting the record Madden-Julian Oscillation in March 2015

    NASA Astrophysics Data System (ADS)

    Marshall, Andrew G.; Hendon, Harry H.; Wang, Guomin

    2016-01-01

    A Madden-Julian Oscillation (MJO) event dramatically amplified at the beginning of March 2015 as the convective phase traversed an unusually warm central Pacific Ocean. This record amplification also resulted in record amplitude of the MJO based on index measurements since 1974. We explore the possible role of the anomalously high ocean surface temperatures in the equatorial central Pacific for promoting the extraordinary amplification of this MJO event. Forecast sensitivity experiments with the Predictive Ocean Atmosphere Model for Australia show that the enhanced growth of the MJO resulted from amplification of the convective anomaly as it encountered the unusually warm central Pacific. Our results indicate that anomalous sea surface temperature (SST) at the onset of El Niño 2015 promoted the intensification of the MJO. We suggest a two-way interaction whereby initial SST anomalies promoted enhanced MJO activity which then possibly led to enhanced El Niño development.

  8. The impact of the Madden-Julian oscillation on polar surface air temperature

    NASA Astrophysics Data System (ADS)

    Yoo, Changhyun

    This dissertation investigates the impact of the Madden-Julian Oscillation (MJO) on the extratropical surface air temperature (SAT). The underlying idea of this study is that tropical convective heating is linked to the extratropical circulation and SAT through poleward propagating Rossby waves. Given this perspective, two questions are addressed. One is the extent to which the MJO contribute to interdecadal time scale polar amplification of SAT (Chapters 2 and 3) and the other is the mechanism by which the MJO alters the intraseasonal time scale extratropical SAT change (Chapters 4 and 5). Polar amplification, i.e., interdecadal time-scale SAT increase being greatest at high latitudes, is one of prominent features of current climate change. Numerous observational and modeling studies have documented this phenomenon. However, its cause remains uncertain. The surface albedo feedback, which is associated with retreats in snow and ice cover and hence increases in surface albedo with a warmer climate, is the most prominent explanation. However, one of important characteristics of polar amplification is that its maximum amplitude is retained during the winter season when incoming solar radiation is minimal. In Chapters 2 and 3, we show that polar amplification during the 1979--2008 winters is tropically excited. More specifically, we show evidence that polar amplification is linked to interdecadal time scale change in the MJO phase frequency of occurrence. We present both the extended boreal winter (November to March) and austral winter (May to September), with our focus being on winter Hemisphere, where the MJO has strong influence. First, during the 30-year boreal winter, MJO phases 4--6 have occurred with an increased frequency of occurrence while phases 1 and 2 have showed a moderate decrease in their frequency of occurrence. Using lagged composites of the SAT, we show that Arctic warming takes place 1--2 weeks after MJO passes its phases 4--6. Similarly, MJO phases

  9. Monitoring and assessment of anthropogenic activities in mountain lakes: a case of the Fifth Triglav Lake in the Julian Alps.

    PubMed

    Ravnikar, Tina; Bohanec, Marko; Muri, Gregor

    2016-04-01

    The Fifth Triglav Lake is a remote mountain lake in the Julian Alps. The area of the Julian Alps where the lake is situated is protected by law and lies within the Triglav National Park. Mountain lakes in Slovenia were considered for a long time as pristine, unpolluted lakes, but analyses in the last decade revealed considerable human impact even in such remote places. Eutrophication or excessive accumulation of nutrients is the main problem of most lakes in the temperate climatic zone, also in Slovenia. Since the introduction of fish in 1991, the lake is going through a series of changes for which we do not know exactly where they lead, so the monitoring and assessment of anthropogenic activities are of great importance. For this purpose, a qualitative multiattribute decision model was developed with DEX method to assess ecological effects on the lake. The extent of the ecological effects on the lake is assessed using four main parameters: the trophic state, lake characteristics, environmental parameters, and anthropogenic stressors. Dependence of environmental impact on various external factors beyond human control, such as temperature, precipitation, retention time, and factors on which we have influence, such as the amount of wastewater and the presence of fish in the lake, were also evaluated. The following data were measured: chlorophyll a, nutrients, TP, oxygen, C/N ratio, nutrients in sediment, temperature, precipitation, retention time, and volume. We made assumptions about fish and wastewater, which we could not measure. The main contributions of this work are the designed model and the obtained findings for the Fifth Triglav Lake that can help not only scientists in understanding the complexity of lake-watershed systems and interactions among system components but also local authorities to manage and monitor the lake aquatic environment in an effective and efficient way. The model is flexible and can be also used for other lakes, assuming that the used

  10. Monitoring and assessment of anthropogenic activities in mountain lakes: a case of the Fifth Triglav Lake in the Julian Alps.

    PubMed

    Ravnikar, Tina; Bohanec, Marko; Muri, Gregor

    2016-03-01

    The Fifth Triglav Lake is a remote mountain lake in the Julian Alps. The area of the Julian Alps where the lake is situated is protected by law and lies within the Triglav National Park. Mountain lakes in Slovenia were considered for a long time as pristine, unpolluted lakes, but analyses in the last decade revealed considerable human impact even in such remote places. Eutrophication or excessive accumulation of nutrients is the main problem of most lakes in the temperate climatic zone, also in Slovenia. Since the introduction of fish in 1991, the lake is going through a series of changes for which we do not know exactly where they lead, so the monitoring and assessment of anthropogenic activities are of great importance. For this purpose, a qualitative multiattribute decision model was developed with DEX method to assess ecological effects on the lake. The extent of the ecological effects on the lake is assessed using four main parameters: the trophic state, lake characteristics, environmental parameters, and anthropogenic stressors. Dependence of environmental impact on various external factors beyond human control, such as temperature, precipitation, retention time, and factors on which we have influence, such as the amount of wastewater and the presence of fish in the lake, were also evaluated. The following data were measured: chlorophyll a, nutrients, TP, oxygen, C/N ratio, nutrients in sediment, temperature, precipitation, retention time, and volume. We made assumptions about fish and wastewater, which we could not measure. The main contributions of this work are the designed model and the obtained findings for the Fifth Triglav Lake that can help not only scientists in understanding the complexity of lake-watershed systems and interactions among system components but also local authorities to manage and monitor the lake aquatic environment in an effective and efficient way. The model is flexible and can be also used for other lakes, assuming that the used

  11. Influence of the Madden-Julian oscillation on Tibetan Plateau snow cover at the intraseasonal time-scale.

    PubMed

    Li, Wenkai; Guo, Weidong; Hsu, Pang-Chi; Xue, Yongkang

    2016-01-01

    The Tibetan Plateau (TP), known as the third pole of the Earth, has snow cover with intraseasonal to decadal variability that affects weather and climate both inside and outside the TP. However, the factors that generate the TP snow cover (TPSC) anomalies at the intraseasonal time-scale are unclear. This report reveals the influence of the Madden‒Julian oscillation (MJO), which is the most dominant component of the tropical intraseasonal variability, on TPSC. We focus on wintertime snow cover over the central and eastern TP, where the intraseasonal variability is large. TPSC increases/decreases in the MJO phases 8‒1/4-5, when the eastward-propagating MJO suppressed/enhanced convection locates over the Maritime Continent. Such a change in TPSC leads to the most dominant positive/negative anomalies of TPSC in the following phases 2‒3/6‒7 due to the non-significant change of TPSC in these phases. There is anomalous moisture advection over the upstream of the TP caused by MJO-excited large-scale atmospheric circulation. The advection process generates the low-frequency eastward-propagating anomalous water vapour from upstream to the TP that influences precipitation and, eventually, TPSC. PMID:27464569

  12. Regulation of H2O and CO in Tropical Tropopause Layer by the Madden-Julian Oscillation

    NASA Technical Reports Server (NTRS)

    Wong, Sun; Dessler, Andrew E.

    2007-01-01

    Impacts of the Madden-Julian oscillation (MJO) on the water vapor (H2O) and carbon monoxide (CO) abundances in the tropical tropopause layer (TTL) are investigated using Aura Microwave Limb Sounder (MLS) data for November 2004 to May 2005. The effects of the eastward propagation of MJO on H2O and CO abundances in the TTL are evident. Deep convection transports H20 into the upper troposphere up to about the 355-365 K level. Around the 365-375 K level, a dry anomaly is collocated with a cold anomaly, which is above a warm anomaly located near the region of convection enhancement. Tropical mean H20 at 375 K is regulated by the MJO through convection enhancement and coherent with the local MJO-related temperature variation. The locations of dehydration follow the eastward propagation of convection enhancement and its area extent depends on the phase of the MJO. Enhancement of deep convection associated with the MJO also injects CO from the lower troposphere to the TTL up to 375 K. However, tropical mean CO at 375 K responds instantaneously to the large injection event occurring over the African continent.

  13. Aquarius surface salinity and the Madden-Julian Oscillation: The role of salinity in surface layer density and potential energy

    NASA Astrophysics Data System (ADS)

    Guan, Bin; Lee, Tong; Halkides, Daria J.; Waliser, Duane E.

    2014-04-01

    Sea surface salinity (SSS) data from the Aquarius satellite are analyzed along with auxiliary data to investigate the SSS signature of the Madden-Julian Oscillation (MJO) in the equatorial Indian and Pacific Oceans, the effect of evaporation-minus-precipitation (E-P), the implication for the role of ocean dynamics, and the SSS influence on surface density and potential energy. MJO-related SSS changes are consistent with E-P forcing in the western Indian Ocean throughout the MJO cycle and in the central Indian Ocean during the wet phase of the MJO cycle. However, SSS changes cannot be explained by E-P in the central Indian Ocean during the dry phase and in the eastern Indian and western Pacific Oceans throughout the MJO cycle, implying the importance of ocean dynamics. SSS has an overall larger contribution to MJO-related surface density and potential energy anomalies than SST. It partially offsets the SST effect in the western-to-central Indian Ocean and reinforces the SST effect in the eastern Indian and western Pacific Oceans. Ocean modeling and assimilation need to properly account for salinity effects in order to correctly represent mixed layer variability associated with the MJO. Our results also clarify some discrepancy in previous studies about the E-P effect on MJO-related SSS variations.

  14. Influence of the Madden–Julian oscillation on Tibetan Plateau snow cover at the intraseasonal time-scale

    NASA Astrophysics Data System (ADS)

    Li, Wenkai; Guo, Weidong; Hsu, Pang-Chi; Xue, Yongkang

    2016-07-01

    The Tibetan Plateau (TP), known as the third pole of the Earth, has snow cover with intraseasonal to decadal variability that affects weather and climate both inside and outside the TP. However, the factors that generate the TP snow cover (TPSC) anomalies at the intraseasonal time-scale are unclear. This report reveals the influence of the Madden‒Julian oscillation (MJO), which is the most dominant component of the tropical intraseasonal variability, on TPSC. We focus on wintertime snow cover over the central and eastern TP, where the intraseasonal variability is large. TPSC increases/decreases in the MJO phases 8‒1/4–5, when the eastward-propagating MJO suppressed/enhanced convection locates over the Maritime Continent. Such a change in TPSC leads to the most dominant positive/negative anomalies of TPSC in the following phases 2‒3/6‒7 due to the non-significant change of TPSC in these phases. There is anomalous moisture advection over the upstream of the TP caused by MJO-excited large-scale atmospheric circulation. The advection process generates the low-frequency eastward-propagating anomalous water vapour from upstream to the TP that influences precipitation and, eventually, TPSC.

  15. Effective control parameters in deep convection scheme for the improved simulation of the Madden-Julian Oscillation

    NASA Astrophysics Data System (ADS)

    CHOI, J.; Seo, K. H.

    2015-12-01

    This work seeks for the most effective parameters in a deep convection scheme (relaxed Arakawa-Schubert convection scheme) of the National Centers for Environmental Prediction Climate Forecast System model for the improved simulation of the Madden-Julian Oscillation (MJO). A suite of sensitivity experiments are performed in a coupled free run format. Two parameters are found to lead to a significant improvement: a threshold of relative humidity of the boundary layer and a fraction of re-evaporation of convective precipitation. Increasing the strength of these two parameters increases a supply of water vapor and condensate from deep cumulus ensembles to environment in the lower troposphere (especially, 700 hPa), and reduces light rainfall amount that prevents complete organization of convective system. Under a more humid environment (or positive moisture-convection feedback), the space-time spectral signal, eastward propagation, tilted vertical structure of dynamic and thermodynamic variables associated with the MJO are more comparable to observations and a recharge-discharge theory.

  16. Assessing the Importance of the Evaporation-Wind Feedback Mechanism in the Modulation of Simulated Madden-Julian Oscillations

    NASA Technical Reports Server (NTRS)

    Colon, Edward; Lindesay, James; Suarez, Max J.

    1998-01-01

    An examination of simulated Madden-Julian Oscillation (MJO) response to active and suppressed air-sea interactions is made using an aquaplanet model employing a realistic representation of the hydrologic cyle. In general, the evaporation-wind feedback (EWF) results from a coupling between tropical zonal surface wind stresses and evaporation anomalies. Recent observational and theoretical studies have questioned the significance of EWF in sustaining the predominantly wavenumber 1 eastward propagating mode commonly attributed to the interaction between large scale convergence and cumulus-scale convection (conditional instability of the second kind, CISK). To ascertain the nature of the EWF dependence on lower boundary conditions and thus quantify its effect on MJO development, a series of numerical experiments were conducted employing various zonally symmetric sea surface temperature (SST) distributions with active and suppressed EWF mechanisms. Results suggest that a correlation exists between tropical SSTs and the efficacy of the EWF in vertically redistributing heat acquired through surface wind stresses. It has been determined that the removal of the EWF is not a crucial factor in the dampening of the simulated MJO at high equatorial SSTs. The additional energy fed into the developing convective mode by the EWF selectively amplifies higher order wave modes in all numerical experiments thus boosting overall variances in oscillatory responses.

  17. Effective control parameters in a deep convection scheme for improved simulation of the Madden-Julian oscillation

    NASA Astrophysics Data System (ADS)

    Choi, Jin-Ho; Seo, Kyong-Hwan

    2016-07-01

    This work seeks to find the most effective parameters in a deep convection scheme (relaxed Arakawa-Schubert scheme) of the National Centers of Environmental Prediction Climate Forecast System model for improved simulation of the Madden-Julian Oscillation (MJO). A suite of sensitivity experiments are performed by changing physical components such as the relaxation parameter of mass flux for adjustment of the environment, the evaporation rate from large-scale precipitation, the moisture trigger threshold using relative humidity of the boundary layer, and the fraction of re-evaporation of convective (subgrid-scale) rainfall. Among them, the last two parameters are found to produce a significant improvement. Increasing the strength of these two parameters reduces light rainfall that inhibits complete formation of the tropical convective system or supplies more moisture that help increase a potential energy to large-scale environment in the lower troposphere (especially at 700 hPa), leading to moisture preconditioning favorable for further development and eastward propagation of the MJO. In a more humid environment, more organized MJO structure (i.e., space-time spectral signal, eastward propagation, and tilted vertical structure) is produced.

  18. Extended-range forecast of spring rainfall in southern China based on the Madden-Julian Oscillation

    NASA Astrophysics Data System (ADS)

    Li, Wenkai; Hsu, Pang-chi; He, Jinhai; Zhu, Zhiwei; Zhang, Wenjun

    2016-06-01

    Spring (March-May) rainfall after a dry period in winter has a substantial impact on agriculture and water management in populous southern China. The occurrence of low-frequency spring rainfall anomalies has been linked with the tropical Madden-Julian Oscillation (MJO) through its modulation of large-scale circulation and moisture supply over southern China. Using the spatial and temporal information of the MJO as a predictor, an empirical model for extended-range forecasting of spring rainfall in southern China was constructed. We first obtained the coupled patterns between the preceding MJO evolutions (real-time multivariate MJO index) and the succeeding rainfall variability in southern China based on singular value decomposition analysis. Then, a prediction was carried out by projecting the predictor onto the spatiotemporal coupled patterns. Useful skill, in terms of the temporal correlation coefficient (TCC) between the predicted and observed rainfall over southern China, persisted up to a forecast lead-time of six pentads. The forecast amplitude bias in terms of root-mean-square error was around 1.0 standard deviation. Also, the forecast skill was highly dependent on the strength of the MJO signal. During active MJO periods, the TCC skill was around twofold larger than that during weak MJO periods. The current statistical model shows encouraging ability, but additional work is required to improve its forecasting skill.

  19. Madden–Julian Oscillation prediction skill of a new-generation global model demonstrated using a supercomputer

    PubMed Central

    Miyakawa, Tomoki; Satoh, Masaki; Miura, Hiroaki; Tomita, Hirofumi; Yashiro, Hisashi; Noda, Akira T.; Yamada, Yohei; Kodama, Chihiro; Kimoto, Masahide; Yoneyama, Kunio

    2014-01-01

    Global cloud/cloud system-resolving models are perceived to perform well in the prediction of the Madden–Julian Oscillation (MJO), a huge eastward -propagating atmospheric pulse that dominates intraseasonal variation of the tropics and affects the entire globe. However, owing to model complexity, detailed analysis is limited by computational power. Here we carry out a simulation series using a recently developed supercomputer, which enables the statistical evaluation of the MJO prediction skill of a costly new-generation model in a manner similar to operational forecast models. We estimate the current MJO predictability of the model as 27 days by conducting simulations including all winter MJO cases identified during 2003–2012. The simulated precipitation patterns associated with different MJO phases compare well with observations. An MJO case captured in a recent intensive observation is also well reproduced. Our results reveal that the global cloud-resolving approach is effective in understanding the MJO and in providing month-long tropical forecasts. PMID:24801254

  20. Influence of the Madden–Julian oscillation on Tibetan Plateau snow cover at the intraseasonal time-scale

    PubMed Central

    Li, Wenkai; Guo, Weidong; Hsu, Pang-chi; Xue, Yongkang

    2016-01-01

    The Tibetan Plateau (TP), known as the third pole of the Earth, has snow cover with intraseasonal to decadal variability that affects weather and climate both inside and outside the TP. However, the factors that generate the TP snow cover (TPSC) anomalies at the intraseasonal time-scale are unclear. This report reveals the influence of the Madden‒Julian oscillation (MJO), which is the most dominant component of the tropical intraseasonal variability, on TPSC. We focus on wintertime snow cover over the central and eastern TP, where the intraseasonal variability is large. TPSC increases/decreases in the MJO phases 8‒1/4–5, when the eastward-propagating MJO suppressed/enhanced convection locates over the Maritime Continent. Such a change in TPSC leads to the most dominant positive/negative anomalies of TPSC in the following phases 2‒3/6‒7 due to the non-significant change of TPSC in these phases. There is anomalous moisture advection over the upstream of the TP caused by MJO-excited large-scale atmospheric circulation. The advection process generates the low-frequency eastward-propagating anomalous water vapour from upstream to the TP that influences precipitation and, eventually, TPSC. PMID:27464569

  1. Extended-range forecast of spring rainfall in southern China based on the Madden-Julian Oscillation

    NASA Astrophysics Data System (ADS)

    Li, Wenkai; Hsu, Pang-chi; He, Jinhai; Zhu, Zhiwei; Zhang, Wenjun

    2015-11-01

    Spring (March-May) rainfall after a dry period in winter has a substantial impact on agriculture and water management in populous southern China. The occurrence of low-frequency spring rainfall anomalies has been linked with the tropical Madden-Julian Oscillation (MJO) through its modulation of large-scale circulation and moisture supply over southern China. Using the spatial and temporal information of the MJO as a predictor, an empirical model for extended-range forecasting of spring rainfall in southern China was constructed. We first obtained the coupled patterns between the preceding MJO evolutions (real-time multivariate MJO index) and the succeeding rainfall variability in southern China based on singular value decomposition analysis. Then, a prediction was carried out by projecting the predictor onto the spatiotemporal coupled patterns. Useful skill, in terms of the temporal correlation coefficient (TCC) between the predicted and observed rainfall over southern China, persisted up to a forecast lead-time of six pentads. The forecast amplitude bias in terms of root-mean-square error was around 1.0 standard deviation. Also, the forecast skill was highly dependent on the strength of the MJO signal. During active MJO periods, the TCC skill was around twofold larger than that during weak MJO periods. The current statistical model shows encouraging ability, but additional work is required to improve its forecasting skill.

  2. Sources of suspended-sediment loads in the lower Nueces River watershed, downstream from Lake Corpus Christi to the Nueces Estuary, south Texas, 1958–2010

    USGS Publications Warehouse

    Ockerman, Darwin J.; Heitmuller, Franklin T.; Wehmeyer, Loren L.

    2013-01-01

    The HSPF model was calibrated to simulate suspended sediment using suspended-sediment data collected at the Mathis, Bluntzer, and Calallen gages during 2006-7. Model simulated suspended-sediment loads at the Calallen gage were within 5 percent of loads that were estimated, by regression, from suspended-sediment sample analysis and measured streamflow. The calibrated watershed model was used to estimate streamflow and suspended-sediment loads for 1958-2010, including loads transported to the Nueces Estuary. During 1958-2010, on average, an estimated 288 tons per day (tons/d) of suspended sediment were delivered to the lower Nueces River; an estimated 278 tons/d were delivered to the estuary. The annual suspended-sediment load was highly variable, depending on the occurrence of runoff events and high streamflows. During 1958-2010, the annual total sediment loads to the estuary varied from an estimated 3.8 to 2,490 tons/d. On average, 113 tons/d, or about 39 percent of the estimated annual suspended-sediment contribution, originated from cropland in the study watershed. Releases from Lake Corpus Christi delivered an estimated 94 tons/d of suspended sediment or about 33 percent of the 288 tons/d estimated to have been delivered to the lower Nueces River. Erosion of stream-channel bed and banks accou

  3. Vertical structure and physical processes of the Madden-Julian Oscillation: Biases and uncertainties at short range

    NASA Astrophysics Data System (ADS)

    Xavier, Prince K.; Petch, Jon C.; Klingaman, Nicholas P.; Woolnough, Steve J.; Jiang, Xianan; Waliser, Duane E.; Caian, Mihaela; Cole, Jason; Hagos, Samson M.; Hannay, Cecile; Kim, Daehyun; Miyakawa, Tomoki; Pritchard, Michael S.; Roehrig, Romain; Shindo, Eiki; Vitart, Frederic; Wang, Hailan

    2015-05-01

    An analysis of diabatic heating and moistening processes from 12 to 36 h lead time forecasts from 12 Global Circulation Models are presented as part of the "Vertical structure and physical processes of the Madden-Julian Oscillation (MJO)" project. A lead time of 12-36 h is chosen to constrain the large-scale dynamics and thermodynamics to be close to observations while avoiding being too close to the initial spin-up of the models as they adjust to being driven from the Years of Tropical Convection (YOTC) analysis. A comparison of the vertical velocity and rainfall with the observations and YOTC analysis suggests that the phases of convection associated with the MJO are constrained in most models at this lead time although the rainfall in the suppressed phase is typically overestimated. Although the large-scale dynamics is reasonably constrained, moistening and heating profiles have large intermodel spread. In particular, there are large spreads in convective heating and moistening at midlevels during the transition to active convection. Radiative heating and cloud parameters have the largest relative spread across models at upper levels during the active phase. A detailed analysis of time step behavior shows that some models show strong intermittency in rainfall and differences in the precipitation and dynamics relationship between models. The wealth of model outputs archived during this project is a very valuable resource for model developers beyond the study of the MJO. In addition, the findings of this study can inform the design of process model experiments, and inform the priorities for field experiments and future observing systems.

  4. Tropical Atlantic Dust and Smoke Aerosol Variabilities Related to the Madden-Julian Oscillation in MODIS and MISR Observations

    NASA Technical Reports Server (NTRS)

    Guo, Yanjuan; Tian, Baijun; Kahn, Ralph A.; Kalashnikova, Olga; Wong, Sun; Waliser, Duane E.

    2012-01-01

    In this study, MODIS fine mode fraction and MISR non-spherical fraction are 2used to derive dust and smoke AOT components (tau(sub dust) and tau(sub smoke)) over the tropical Atlantic, and their variabilities related to the Madden-Julian Oscillation (MJO) are then investigated. Both MODIS and MISR show a very similar dust and smoke winter climatology. tau(sub dust) is found to be the dominant aerosol component over the tropical Atlantic while tau(sub smoke) is significantly smaller than tau(sub dust). The daily MODIS and MISR tau(sub dust) are overall highly correlated, with the correlation coefficients typically about 0.7 over the North Atlantic. The consistency between the MODIS and MISR dust and smoke aerosol climatology and daily variations give us confidence to use these two data sets to investigate their relative contributions to the total AOT variation associated with the MJO. However, unlike the MISR dust discrimination, which is based on particle shape retrievals, the smoke discrimination is less certain, based on assumed partitioning of maritime aerosol for both MISR and MODIS. The temporal evolution and spatial patterns of the tau(sub dust) anomalies associated with the MJO are consistent between MODIS and MISR. The tau(sub dust) anomalies are very similar to those of tau anomalies, and are of comparable magnitude. In contrast, the MJO-related tau(sub smoke) anomalies are rather small, and the tau(sub mar) anomalies are negligible. The consistency between the MODIS and MISR results suggests that dust aerosol is the dominant component on the intra-seasonal time scale over the tropical Atlantic Ocean.

  5. Storm track activity over the North Pacific associated with the Madden-Julian Oscillation under ENSO conditions during boreal winter

    NASA Astrophysics Data System (ADS)

    Takahashi, Chiharu; Shirooka, Ryuichi

    2014-09-01

    The present study investigates modulation by the Madden-Julian Oscillation (MJO) of storm track activity (STA) over the North Pacific (NP) during boreal winter for El Niño and La Niña periods. STA defined by vertically averaged synoptic eddy kinetic energy (EKE) greatly intensifies over the western North Pacific (WNP) and central eastern North Pacific during La Niña and El Niño years, respectively, when the MJO convection is located over the central Indian Ocean (IO)-Maritime Continent. When the MJO moves into the western central Pacific, the STA in La Niña years is suppressed (enhanced) at higher (lower) latitudes than in El Niño years. Diagnoses of EKE and eddy available potential energy budgets indicate that the difference in STA over the WNP for the MJO phases between El Niño-Southern Oscillation (ENSO) years is mainly contributed by baroclinic energy conversion and potential energy conversion between background and eddy (BCPE). We reveal that BCPE is mainly attributed to intraseasonal baroclinicity and eddy heat flux (EHF) anomalies and their interactions with strong winter mean baroclinic fields in the WNP. Through the EHF, synoptic eddies act to counterbalance an intraseasonal temperature that is primarily caused by the anomalous horizontal advection of mean temperature by MJO-related flow. The intraseasonal circulation and associated temperature and EHF anomalies dominate in northwest (southeast) portion of the NP during La Niña (El Niño), leading to BCPE difference. Changes in the spatial pattern and strength of the NP circulation and STA are caused by dominance of strong MJO amplification over the IO (central Pacific) during La Niña (El Niño).

  6. Tropical Atlantic Dust and Smoke Aerosol Variations Related to the Madden-Julian Oscillation in MODIS and MISR Observations

    NASA Technical Reports Server (NTRS)

    Guo, Yanjuan; Tian, Baijun; Kahn, Ralph A.; Kalashnikova, Olga; Wong, Sun; Waliser, Duane E.

    2013-01-01

    In this study, Moderate Resolution Imaging Spectroradiometer (MODIS) fine mode fraction and Multi-angle Imaging SpectroRadiometer (MISR) nonspherical fraction data are used to derive dust and smoke aerosol optical thickness (T(sub dust) and T(sub smoke)) over the tropical Atlantic in a complementary way: due to its wider swath, MODIS has 3-4 times greater sampling than MISR, but MISR dust discrimination is based on particle shape retrievals, whereas an empirical scheme is used for MODIS. MODIS and MISR show very similar dust and smoke winter climatologies. T(sub dust) is the dominant aerosol component over the tropical Atlantic, accounting for 40-70 percent of the total aerosol optical thickness (AOT), whereas T(sub smoke) is significantly smaller than T(sub dust). The consistency and high correlation between these climatologies and their daily variations lends confidence to their use for investigating the relative dust and smoke contributions to the total AOT variation associated with the Madden-Julian Oscillation (MJO). The temporal evolution and spatial patterns of the tdus anomalies associated with the MJO are consistent between MODIS and MISR: the magnitude of MJO-realted T(sub dust) anomalies is comparable to or even larger than that of the total T, while the T(sub smoke) anomaly represents about 15 percent compared to the total, which is quite different from their relative magnitudes to the total T on the climatological time scale. This suggests that dust and smoke are not influenced by the MJO in the same way. Based on correlation analysis, dust is strongly influenced by the MJO-modulated trade wind and precipitation anomalies, and can last as long as one MJO phase, whereas smoke is less affected.

  7. Vertical structure and physical processes of the Madden-Julian oscillation: Exploring key model physics in climate simulations

    NASA Astrophysics Data System (ADS)

    Jiang, Xianan; Waliser, Duane E.; Xavier, Prince K.; Petch, Jon; Klingaman, Nicholas P.; Woolnough, Steven J.; Guan, Bin; Bellon, Gilles; Crueger, Traute; DeMott, Charlotte; Hannay, Cecile; Lin, Hai; Hu, Wenting; Kim, Daehyun; Lappen, Cara-Lyn; Lu, Mong-Ming; Ma, Hsi-Yen; Miyakawa, Tomoki; Ridout, James A.; Schubert, Siegfried D.; Scinocca, John; Seo, Kyong-Hwan; Shindo, Eiki; Song, Xiaoliang; Stan, Cristiana; Tseng, Wan-Ling; Wang, Wanqiu; Wu, Tongwen; Wu, Xiaoqing; Wyser, Klaus; Zhang, Guang J.; Zhu, Hongyan

    2015-05-01

    Aimed at reducing deficiencies in representing the Madden-Julian oscillation (MJO) in general circulation models (GCMs), a global model evaluation project on vertical structure and physical processes of the MJO was coordinated. In this paper, results from the climate simulation component of this project are reported. It is shown that the MJO remains a great challenge in these latest generation GCMs. The systematic eastward propagation of the MJO is only well simulated in about one fourth of the total participating models. The observed vertical westward tilt with altitude of the MJO is well simulated in good MJO models but not in the poor ones. Damped Kelvin wave responses to the east of convection in the lower troposphere could be responsible for the missing MJO preconditioning process in these poor MJO models. Several process-oriented diagnostics were conducted to discriminate key processes for realistic MJO simulations. While large-scale rainfall partition and low-level mean zonal winds over the Indo-Pacific in a model are not found to be closely associated with its MJO skill, two metrics, including the low-level relative humidity difference between high- and low-rain events and seasonal mean gross moist stability, exhibit statistically significant correlations with the MJO performance. It is further indicated that increased cloud-radiative feedback tends to be associated with reduced amplitude of intraseasonal variability, which is incompatible with the radiative instability theory previously proposed for the MJO. Results in this study confirm that inclusion of air-sea interaction can lead to significant improvement in simulating the MJO.

  8. The global response to vertical diabatic heating structures associated with the Madden-Julian oscillation derived from TRMM estimates

    NASA Astrophysics Data System (ADS)

    Taylor, J.; Woolnough, S.; Inness, P.

    2013-12-01

    The anomalous global atmospheric circulation associated with the Madden-Julian oscillation (MJO) is examined using composite vertical anomalous diabatic heating structures based on Tropical Rainfall Measuring Mission (TRMM) estimates and reanalysis datasets and integrating a primitive equations model. Variations in the dynamical response from the observational and reanalysis products are investigated in relation to the detailed structure of the vertical structure of heating of the MJO, with specific focus of the role of the westward tilting with altitude in the heating, clearly evident in three reanalysis heating structures but is less well pronounced in the TRMM heating structures. It was found that the atmospheric response to the reanalysis heatings were far more consistent compared to the responses from the TRMM heating estimates. Examination of the moisture flux during the main active phase of the MJO revealed a surplus in moisture convergence ahead of the anomalous heating from each of the reanalysis integrations, which was found to be directly attributed to the vertical tilt in heating structure. In contrast, the response to the TRMM heatings showed no phase shift in moisture convergence in relation to the convective heating and was understood to be a consequence of the weaker representation of vertical tilting in heating structure. It was suggested that the westward tilt in heating could therefore play an important role in promoting convection east of the main heating region. The dynamical response to composite vertical diabatic heating structures associated with the MJO from simulations with Unified Model (UM) HadGEM3 with standard and enhanced (x1.5) entrainment rates are also examined to investigate the relationship between the dynamical response to the heating profile and quality of MJO simulations.

  9. Vertical structure and physical processes of the Madden-Julian Oscillation: Biases and uncertainties at short range

    SciTech Connect

    Xavier, Prince K.; Petch, Jon C.; Klingaman, Nicholas P.; Woolnough, Steve J.; Jiang, Xianan; Waliser, Duane E.; Caian, Mihaela; Cole, Jason; Hagos, Samson M.; Hannay, Cecile; Kim, Daehyun; Miyakawa, Tomoki; Pritchard, Michael S.; Roehrig, Romain; Shindo, Eiki; Vitart, Frederic; Wang, Hailan

    2015-05-26

    We present an analysis of diabatic heating and moistening processes from 12 to 36 h lead time forecasts from 12 Global Circulation Models as part of the “Vertical structure and physical processes of the Madden-Julian Oscillation (MJO)” project. A lead time of 12–36 h is chosen to constrain the large-scale dynamics and thermodynamics to be close to observations while avoiding being too close to the initial spin-up of the models as they adjust to being driven from the Years of Tropical Convection (YOTC) analysis. A comparison of the vertical velocity and rainfall with the observations and YOTC analysis suggests that the phases of convection associated with the MJO are constrained in most models at this lead time although the rainfall in the suppressed phase is typically overestimated. Although the large-scale dynamics is reasonably constrained, moistening and heating profiles have large intermodel spread. In particular, there are large spreads in convective heating and moistening at midlevels during the transition to active convection. Radiative heating and cloud parameters have the largest relative spread across models at upper levels during the active phase. A detailed analysis of time step behavior shows that some models show strong intermittency in rainfall and differences in the precipitation and dynamics relationship between models. In conclusion, the wealth of model outputs archived during this project is a very valuable resource for model developers beyond the study of the MJO. Additionally, the findings of this study can inform the design of process model experiments, and inform the priorities for field experiments and future observing systems.

  10. Vertical structure and physical processes of the Madden-Julian Oscillation: Biases and uncertainties at short range

    DOE PAGESBeta

    Xavier, Prince K.; Petch, Jon C.; Klingaman, Nicholas P.; Woolnough, Steve J.; Jiang, Xianan; Waliser, Duane E.; Caian, Mihaela; Cole, Jason; Hagos, Samson M.; Hannay, Cecile; et al

    2015-05-26

    We present an analysis of diabatic heating and moistening processes from 12 to 36 h lead time forecasts from 12 Global Circulation Models as part of the “Vertical structure and physical processes of the Madden-Julian Oscillation (MJO)” project. A lead time of 12–36 h is chosen to constrain the large-scale dynamics and thermodynamics to be close to observations while avoiding being too close to the initial spin-up of the models as they adjust to being driven from the Years of Tropical Convection (YOTC) analysis. A comparison of the vertical velocity and rainfall with the observations and YOTC analysis suggests thatmore » the phases of convection associated with the MJO are constrained in most models at this lead time although the rainfall in the suppressed phase is typically overestimated. Although the large-scale dynamics is reasonably constrained, moistening and heating profiles have large intermodel spread. In particular, there are large spreads in convective heating and moistening at midlevels during the transition to active convection. Radiative heating and cloud parameters have the largest relative spread across models at upper levels during the active phase. A detailed analysis of time step behavior shows that some models show strong intermittency in rainfall and differences in the precipitation and dynamics relationship between models. In conclusion, the wealth of model outputs archived during this project is a very valuable resource for model developers beyond the study of the MJO. Additionally, the findings of this study can inform the design of process model experiments, and inform the priorities for field experiments and future observing systems.« less

  11. Evidence for a modulation of the intraseasonal summer temperature in Eastern Patagonia by the Madden-Julian Oscillation

    NASA Astrophysics Data System (ADS)

    Jacques-Coper, Martín.; Brönnimann, Stefan; Martius, Olivia; Vera, Carolina S.; Cerne, S. Bibiana

    2015-08-01

    We describe the relationship between the intraseasonal component of surface air temperature (SAT) variability in Eastern Patagonia and the Madden-Julian Oscillation (MJO) during austral summer based on ~50 years of daily instrumental records, the Twentieth Century Reanalysis, and a century-long MJO index reconstruction. Our results show that the summer SAT variability in Patagonia is highly driven by the intraseasonal activity (~80%), especially by that associated with the MJO. The active MJO phases modulate the spatial mean intraseasonal temperature signal in Eastern Patagonia with ~1.5°C of amplitude. In most of the region, the warmest (coldest) conditions are found during active phase 8 (4). These opposite states of the temperature perturbations are related to almost inverse midlevel circulation anomalies over southern South America and the southwest Atlantic, which are part of a large-scale Rossby-like wave train of alternating circulation anomalies extended along the South Pacific. The corresponding outgoing longwave radiation anomalies suggest that these structures may be triggered by anomalous convection in the tropics. Furthermore, we show that intraseasonal heat waves in southeastern Patagonia tend to occur during active MJO phase 8. These events are also induced by a wave train pattern over the South Pacific, associated with other intraseasonal variability sources. Hence, as shown in a case study, circulation anomalies over the South Pacific triggered, in general, by tropical convection variability and, in particular, by the MJO activity may constructively interact with circulation patterns resulting from the extratropical dynamics, eventually leading to intraseasonal heat waves in southeastern Patagonia.

  12. Satellite measurements of the Madden-Julian oscillation in wintertime stratospheric ozone over the Tibetan Plateau and East Asia

    NASA Astrophysics Data System (ADS)

    Zhang, Yuli; Liu, Yi; Liu, Chuanxi; Sofieva, V. F.

    2015-11-01

    We investigate the Madden-Julian Oscillation (MJO) signal in wintertime stratospheric ozone over the Tibetan Plateau and East Asia using the harmonized dataset of satellite ozone profiles. Two different MJO indices—the all-season Real-Time multivariate MJO index (RMM) and outgoing longwave radiation-based MJO index (OMI)—are used to compare the MJO-related ozone anomalies. The results show that there are pronounced eastward-propagating MJO-related stratospheric ozone anomalies (mainly within 20-200 hPa) over the subtropics. The negative stratospheric ozone anomalies are over the Tibetan Plateau and East Asia in MJO phases 4-7, when MJO-related tropical deep convective anomalies move from the equatorial Indian Ocean towards the western Pacific Ocean. Compared with the results based on RMM, the MJO-related stratospheric column ozone anomalies based on OMI are stronger and one phase ahead. Further analysis suggests that different sampling errors, observation principles and retrieval algorithms may be responsible for the discrepancies among different satellite measurements. The MJO-related stratospheric ozone anomalies can be attributed to the MJO-related circulation anomalies, i.e., the uplifted tropopause and the northward shifted westerly jet in the upper troposphere. Compared to the result based on RMM, the upper tropospheric westerly jet may play a less important role in generating the stratospheric column ozone anomalies based on OMI. Our study indicates that the circulation-based MJO index (RMM) can better characterize the MJO-related anomalies in tropopause pressure and thus the MJO influence on atmospheric trace gases in the upper troposphere and lower stratosphere, especially over subtropical East Asia.

  13. Linkages between the Madden Julian Oscillation, process-level diagnostics and GCM parameterization behavior in YOTC simulations

    NASA Astrophysics Data System (ADS)

    Neale, R. B.; Hannay, C.

    2014-12-01

    The simulation of the Madden Julian Oscillation (MJO) remains a significant challenge in climate models. The primary difficulty lies in relating MJO skill to parameterized physical processes - the main access point for model development. One theory of the MJO relies on scale-interactions from small to large scales. The expectation is that GCMs should reproduce the correct relationships at the smallest resolved scales and this will translate through increasing scales and lead to a skillful simulation of the MJO. So-called 'process-based' diagnostics have recently been applied to simple model fields in order to relate accurate simulation of the MJO to accurate, small-scale process-level relationships (Kim et al., 2014). In this presentation we will take this technique further to provide greater insight into how the underlying physical parameterizations in the Community Atmosphere Model (CAM) conspire to provide the process-level responses in the model, particularly as it relates to precipitation and humidity dependent processes. This provides the potential for a range of dependencies between parameterization tendencies and MJO skill. Furthermore, these dependencies are examined to quantify the effect of model biases. This entails performing the same process-level analysis on simply initialized and nudged CAM simulations that make use of YOTC analysis. These techniques enable diagnosis of the relationship between degrading model simulation (basic state and MJO) and changes in the parameterized response at the process level. In summary, this talk will show the most promising relationships between MJO simulation performance and the fidelity with which the parameterized physics produce observed process-scale relationships.

  14. Response to Julian et al. (2015) "comment on and reinterpretation of Gabriel et al. (2014) 'fish mercury and surface water sulfate relationships in the everglades protection area'".

    PubMed

    Gabriel, Mark C; Axelrad, Don; Orem, William; Osborne, Todd Z

    2015-06-01

    The purpose of this forum is to respond to a rebuttal submitted by Julian et al., Environ Manag 55:1-5, 2015 where they outlined their overall disagreement with the data preparation, methods, and interpretation of results presented in Gabriel et al. (Environ Manag 53:583-593, 2014). Here, we provide background information on the research premise presented in Gabriel et al. (Environ Manag 53:583-593, 2014) and provide a defense for this work using five themes. In spite of what Julian et al. perceive as limitations in the sampling methods and analytical tools used for this work, the relationships found between fish total mercury and surface water sulfate concentrations in Gabriel et al. (Environ Manag 53:583-593, 2014) are comparable to relationships between pore water methylmercury (MeHg) and pore water sulfate found in past studies indicating that sulfate is important to MeHg production and bioaccumulation in the Everglades. Julian et al. state "…there is no way to justify any ecosystem-wide sulfur strategy as a management approach to reduce mercury risk in the (Everglades) as suggested by Gabriel et al. (Environ Manag 53:583-593, 2014), Corrales et al. (Sci Tot Environ 409:2156-2162, 2011) and Orem et al. (Rev Environ Sci Technol 41 (S1):249-288, 2011)." We disagree, and having stated why sulfate input reduction to the Everglades may be the most effective means of reducing mercury in Everglades fish, it is important that research on sulfur and mercury biogeochemistry continues. If further studies support the relationship between sulfate loading reduction and MeHg reduction, sulfur mass balance studies should commence to (1) better quantify agricultural and connate seawater sulfate inputs and (2) define opportunities to reduce sulfate inputs to the Everglades ecosystem. PMID:25860595

  15. Response to Julian et al. (2015) "Comment on and Reinterpretation of Gabriel et al. (2014) `Fish Mercury and Surface Water Sulfate Relationships in the Everglades Protection Area'"

    NASA Astrophysics Data System (ADS)

    Gabriel, Mark C.; Axelrad, Don; Orem, William; Osborne, Todd Z.

    2015-06-01

    The purpose of this forum is to respond to a rebuttal submitted by Julian et al., Environ Manag 55:1-5, 2015 where they outlined their overall disagreement with the data preparation, methods, and interpretation of results presented in Gabriel et al. (Environ Manag 53:583-593, 2014). Here, we provide background information on the research premise presented in Gabriel et al. (Environ Manag 53:583-593, 2014) and provide a defense for this work using five themes. In spite of what Julian et al. perceive as limitations in the sampling methods and analytical tools used for this work, the relationships found between fish total mercury and surface water sulfate concentrations in Gabriel et al. (Environ Manag 53:583-593, 2014) are comparable to relationships between pore water methylmercury (MeHg) and pore water sulfate found in past studies indicating that sulfate is important to MeHg production and bioaccumulation in the Everglades. Julian et al. state "…there is no way to justify any ecosystem-wide sulfur strategy as a management approach to reduce mercury risk in the (Everglades) as suggested by Gabriel et al. (Environ Manag 53:583-593, 2014), Corrales et al. (Sci Tot Environ 409:2156-2162, 2011) and Orem et al. (Rev Environ Sci Technol 41 (S1):249-288, 2011)." We disagree, and having stated why sulfate input reduction to the Everglades may be the most effective means of reducing mercury in Everglades fish, it is important that research on sulfur and mercury biogeochemistry continues. If further studies support the relationship between sulfate loading reduction and MeHg reduction, sulfur mass balance studies should commence to (1) better quantify agricultural and connate seawater sulfate inputs and (2) define opportunities to reduce sulfate inputs to the Everglades ecosystem.

  16. Comment on "Methodology and results of calculating Central California surface temperature trends: evidence of human-induced climate change?" by Christy et al. (2006)

    SciTech Connect

    Bonfils, C; Duffy, P; Lobell, D

    2006-03-28

    Understanding the causes of observed regional temperature trends is essential to projecting the human influences on climate, and the societal impacts of these influences. In their recent study, Christy et al. (2006, hereinafter CRNG06) hypothesized that the presence of irrigated soils is responsible for rapid warming of summer nights occurring in California's Central Valley over the last century (1910-2003), an assumption that rules out any significant effect due to increased greenhouse gases, urbanization, or other factors in this region. We question this interpretation, which is based on an apparent contrast in summer nighttime temperature trends between the San Joaquin Valley ({approx} +0.3 {+-} 0.1 C/decade) and the adjacent western slopes of the Sierra Nevada (-0.25 {+-} 0.15 C/decade), as well as the amplitude, sign and uncertainty of the Sierra nighttime temperature trend itself. We, however, do not dispute the finding of other Sierra and Valley trends. Regarding the veracity of the apparent Sierra nighttime temperature trend, CRNG06 generated the Valley and Sierra time-series using a meticulous procedure that eliminates discontinuities and isolates homogeneous segments in temperature records from 41 weather stations. This procedure yields an apparent cooling of about -0.25 {+-} 0.15 C/decade in the Sierra region. However, because removal of one of the 137 Sierra segments, from the most elevated site (Huntington Lake, 2140m), causes an increase in nighttime temperature trend as large as the trend itself (of +0.25 C/decade, CH06), and leads to a zero trend, the apparent cooling of summer nights in the Sierra regions seems, in fact, largely uncertain.

  17. The Modulation of Tropical Storm Activity in the Western North Pacific by the Madden-Julian Oscillation in GEOS-5 AGCM Experiments

    NASA Technical Reports Server (NTRS)

    Kim, Dongmin; Lee, Myong-In; Kim, Hye-Mi; Schubert, Siegfried D.; Yoo, Jin H.

    2014-01-01

    This study examines the influence of the Madden-Julian Oscillation (MJO) on tropical storm (TS) activity in the western North Pacific, using observations and GEOS-5 simulations at 50-km horizontal resolution. While GEOS-5 produces an MJO of faster propagation and weaker amplitude, it nevertheless reproduces the observed modulation of TS activity by the MJO with the highest TS genesis and increased track density in the active phases of MJO. The study suggests that the simulation of the sub-seasonal variability of TS activity could be improved by improving the simulations of the MJO in climate models.

  18. Role of the Atmospheric Mean State on the Initiation of the Madden-Julian Oscillation in a Tropical Channel Model

    SciTech Connect

    Ray, Pallav; Zhang, Chidong; Moncrieff, Mitch; Dudhia, Jimy; Caron, Julie M.; Leung, Lai-Yung R.; Bruyere, Cindy

    2010-06-08

    Tropical channel models, defined as models that are global in the zonal direction but bounded in the meridional direction, are particularly useful for simulating the Madden-Julian oscillation (MJO) and understanding its physical and dynamical basis. Influences from the extratropics through the lateral boundaries have been found to be essential to the reproduction of the initiation of certain MJO events. This led to a hypothesis that multi-year simulations using a tropical channel model would reproduce reasonable MJO statistics under the influence of prescribed lateral boundary conditions derived from global reanalyses. Interestingly, the MJO statistics in such a multi-year simulation by a high-resolution tropical channel model are not better than those from global climate models. The error in the atmospheric mean state is found to be a possible reason for the poor MJO statistics in the simulation. Nevertheless, even with a large error in the mean state, the multi-year simulation captures two MJO events previously found to be initiated by extratropical influences. However, the model does not reproduce a third event, whose initiation is not directly influenced by the extratropics. This implies that in the absence of dynamical interactions between the MJO and the lateral boundary conditions, the error in the mean state could be sufficient to prevent the MJO initiation. To explore this third MJO event further, a series of sensitivity tests are conducted. These tests show that the simulation of this event is neither critically influenced by the cumulus parameterization employed, nor the initial conditions when the model is integrated 2 weeks prior to the MJO initiation. The model captures this event when the MJO signal is already present in the initial conditions. The use of highresolution sea surface temperature does not improve the simulation of the third MJO event. A higher-resolution nested domain covering the Indo-Pacific warm pool region and including a cloud

  19. Response to ?A Madden-Julian Oscillation Event Realistically Simulated by a Global Cloud-Resolving Model?

    SciTech Connect

    Sperber, K R

    2007-12-18

    I agree with the authors that forecasting the Madden-Julian Oscillation (MJO) in a high resolution global model is important for numerous reasons, including improved weather forecast skill beyond 10 days, and resolving small scale features embedded in the MJO that coarse resolution ({approx}100-300km horizontal grid spacing) climate models do not (e.g., tropical cyclones). Unfortunately, the authors promote the (incorrect) overall impression that coarse resolution climate models cannot simulate the MJO by (a) only discussing aspects of works that indicate the poor ability of coarse resolution climate models to simulate the MJO, and (b) by promoting the use of higher resolution models, and the use of embedded two-dimensional cloud resolving models embedded in coarse resolution climate models as the principal methods for realistically representing the MJO because of the difficulty of coarse resolution models 'to estimate the vertical redistribution of heat and moisture by unresolved convective clouds'. Regarding items (a) and (b), I have co-authored two of the works cited by Miura et al. that bemoan the poor ability of coarse resolution climate models to simulate the MJO, and indeed simulating the MJO in coarse resolution climate models is a grand challenge. However, I would like to draw to their attention to work that has demonstrated that two different coarse resolution climate models, using conventional parameterizations of convection and clouds, can represent the MJO with high fidelity. In the later study, where more complete model diagnostics were available, important aspects of the MJO that were realistically represented included the relationship between convection and low-level moisture convergence, surface fluxes, the vertical structure of winds and divergence, and important air-sea interactions. Additionally, regarding item (b), convection is certainly of central importance in representing the MJO, but it is the interaction of convection (parameterized or

  20. AMIE (ARM MJO Investigation Experiment): Observations of the Madden-Julian Oscillation for Modeling Studies Science Plan

    SciTech Connect

    Long, C; Del Genio, A; Gustafson, W; Houze, R; Jakob, C; Jensen, M; Klein, S; Leung, L Ruby; Liu, X; Luke, E; May, P; McFarlane, S; Minnis, P; Schumacher, C; Vogelmann, A; Wang, Y; Wu, X; Xie, S

    2010-03-22

    Deep convection in the tropics plays an important role in driving global circulations and the transport of energy from the tropics to the mid-latitudes. Understanding the mechanisms that control tropical convection is a key to improving climate modeling simulations of the global energy balance. One of the dominant sources of tropical convective variability is the Madden-Julian Oscillation (MJO), which has a period of approximately 30–60 days. There is no agreed-upon explanation for the underlying physics that maintain the MJO. Many climate models do not show well-defined MJO signals, and those that do have problems accurately simulating the amplitude, propagation speed, and/or seasonality of the MJO signal. Therefore, the MJO is a very important modeling target for the ARM modeling community geared specifically toward improving climate models. The ARM MJO Investigation Experiment (AMIE) period coincides with a large international MJO initiation field campaign called CINDY2011 (Cooperative Indian Ocean experiment on intraseasonal variability in the Year 2011) that will take place in and around the Indian Ocean from October 2011 to January 2012. AMIE, in conjunction with CINDY2011 efforts, will provide an unprecedented data set that will allow investigation of the evolution of convection within the framework of the MJO. AMIE observations will also complement the long-term MJO statistics produced using ARM Manus data and will allow testing of several of the current hypotheses related to the MJO phenomenon. Taking advantage of the expected deployment of a C-POL scanning precipitation radar and an ECOR surface flux tower at the ARM Manus site, we propose to increase the number of sonde launches to eight per day starting in about mid-October of the field experiment year, which is climatologically a period of generally suppressed conditions at Manus and just prior to the climatologically strongest MJO period. The field experiment will last until the end of the MJO

  1. Physical Mechanisms for the Maintenance of GCM-Simulated Madden-Julian Oscillation over the Indian Ocean and Pacific

    SciTech Connect

    Deng, Liping; Wu, Xiaoqing

    2011-05-05

    The kinetic energy budget is conducted to analyze the physical processes responsible for the improved Madden-Julian Oscillation (MJO) simulated by the Iowa State University general circulation models (ISUGCM). The modified deep convection scheme that includes the revised convection closure, convection trigger condition and convective momentum transport (CMT) enhances the equatorial (10oS-10oN) MJO-related perturbation kinetic energy (PKE) in the upper troposphere and leads to more robust and coherent eastward propagating MJO signal. In the MJO source region-the Indian Ocean (45oE-120oE), the upper-tropospheric MJO PKE is maintained by the vertical convergence of wave energy flux and the barotropic conversion through the horizontal shear of mean flow. In the convectively active region-the western Pacific (120oE-180o), the upper-tropospheric MJO PKE is supported by the convergence of horizontal and vertical wave energy fluxes. Over the central-eastern Pacific (180o-120oW), where convection is suppressed, the upper-tropospheric MJO PKE is mainly due to the horizontal convergence of wave energy flux. The deep convection trigger condition produces stronger convective heating which enhances the perturbation available potential energy (PAPE) production and the upward wave energy fluxes, and leads to the increased MJO PKE over the Indian Ocean and western Pacific. The trigger condition also enhances the MJO PKE over the central-eastern Pacific through the increased convergence of meridional wave energy flux from the subtropical latitudes of both hemispheres. The revised convection closure affects the response of mean zonal wind shear to the convective heating over the Indian Ocean and leads to the enhanced upper-tropospheric MJO PKE through the barotropic conversion. The stronger eastward wave energy flux due to the increase of convective heating over the Indian Ocean and western Pacific by the revised closure is favorable to the eastward propagation of MJO and the

  2. Geomorphological map and preliminary analysis of Quaternary sediments in the Planica-Tamar valley (Julian Alps, NW Slovenia)

    NASA Astrophysics Data System (ADS)

    Novak, Andrej; Šmuc, Andrej

    2016-04-01

    The Planica-Tamar valley is located in the Julian Alps in north-west Slovenia. The Planica-Tamar valley represents typical mountain glacial valley bounded by steep, mainly carbonate cliffs with some glacial deposits still preserved. The valley is currently being filled with numerous Holocene sediments deposited by rock falls, landslides, mass gravity flows and fluvial flows. These deposits are forming active or inactive interfingering talus slopes, alluvial and debris-flow fans, all of them with a complex history of sedimentation and erosion forming unconformity bounded sedimentary units. In order to make a thorough analysis of these deposits a detailed geomorphological map in a scale of 1:10 000 has been made. Six different types of sedimentary deposits were defined and mapped. These are moraines, lacustrine sediments, fluvio-glacial deposits, talus slopes, debris fans and alluvial fans. Other mapped features also include shape of ravines, their depths, ridges and direction of sedimentary flow. Additionally areas of active, semi-active and inactive sedimentation were marked. Moraines forms a ridge in the bottom of the valleys and are composed of unconsolidated, poorly sorted, subangular grains ranging from clay size to a few cubic meters big blocks. Lacustrine sediments are represented by laminated well sorted sand and silt, while fluvio-glacial deposits are composed of washed out subrounded sands and gravels. Talus slope deposits are characterised by clast-supported poorly sorted very angular gravel. Debris flow fans are represented by extremely poorly sorted matrix-supported gravels with grain size ranging from clay to few cubic meters big blocks. Alluvial fans are composed by variety of sedimentary textures. Sediments at the fan apex are clast-supported poorly sorted very angular gravels with up to a few cubic meters big block. In the middle part of the fan the sieve deposits are common, while in the distal parts a few centimeters thick layers of sand and

  3. On the predictability of the interannual behaviour of the Madden-Julian oscillation and its relationship with El Nino

    SciTech Connect

    Sperber, K.R., LLNL

    1998-03-01

    The Madden-Julian Oscillation (MJO) is the dominant mode of tropical variability at intraseasonal timescales. It displays substantial interannual variability in intensity which may have important implications for the predictability of the coupled system. The reasons for this interannual variability are not understood. The aim of this paper is to investigate whether the interannual behavior of the MJO is related to tropical sea surface temperature (SST) anomalies, particularly El Nino, and hence whether it is predictable. The interannual behavior of the MJO has been diagnosed initially in the 40-year NCEP/ NCAR Reanalysis. The results suggest that prior to the mid-1970s the activity of the MJO was consistently lower than during the latter part of the record. This may be related to either inadequacies in the data coverage, particularly over the tropical Indian Ocean prior to the introduction of satellite observations, or to the real effects of a decadal timescale warming in the tropical SSTs. The teleconnection patterns between interannual variations in MJO activity and SST show only a weak, barely significant, influence of El Nino in which the MJO is more active during the cold phase. As well as the NCEP/NCAR Reanalysis, a 4-member ensemble of 45 year integrations with the Hadley Centre climate model (HadAM2a), forced by observed SSTs for 1949-93, has been used to investigate the relationship between MJO activity and SST. HadAM2a is known to give a reasonable simulation of the MJO and the extended record provided by this ensemble of integrations allows a more robust investigation of the predictability of MJO activity than was possible with the 40-year NCEP/NCAR Reanalysis. The results have shown that, for the uncoupled system, with the atmosphere being driven by imposed SSTS, there is no reproducibility for the activity of the MJO from year to year. The interannual behavior of the MJO is not controlled by the phase of El Nino and would appear to be chaotic in

  4. Exploring the Utility of the Planned CYGNSS Mission for Investigating the Initiation and Development of the Madden-Julian Oscillation

    NASA Technical Reports Server (NTRS)

    Lang, Timothy; Mecikalski, John; Li, Xuanli; Chronis, Themis; Brewer, Alan; Churnside, James; Rutledge, Steve

    2014-01-01

    CYGNSS is a planned constellation consisting of multiple micro-satellites that leverage the Global Positioning System (GPS) to provide rapidly updated, high resolution (approx. 15-50 km, approx. 4 h) surface wind speeds (via bi-static scatterometry) over the tropical oceans in any weather condition, including heavy rainfall. The approach of the work to be presented at this conference is to utilize a limited-domain, cloud-system resolving model (Weather Research and Forecasting or WRF) and its attendant data assimilation scheme (Three-Dimensional Variational Assimilation or 3DVAR) to investigate the utility of the CYGNSS mission for helping characterize key convectiveto- mesoscale processes - such as surface evaporation, moisture advection and convergence, and upscale development of precipitation systems - that help drive the initiation and development of the Madden-Julian Oscillation (MJO) in the equatorial Indian Ocean. The proposed work will focus on three scientific objectives. Objective 1 is to produce a high-resolution surface wind dataset resolution (approx. 0.5 h, approx. 1-4 km) for multiple MJO onsets using WRF-assimilated winds and other data from the DYNAmics of the MJO (DYNAMO) field campaign, which took place during October 2011 - March 2012. Objective 2 is to study the variability of surface winds during MJO onsets at temporal and spatial scales of finer resolution than future CYGNSS data. The goal is to understand how sub-CYGNSS-resolution processes will shape the observations made by the satellite constellation. Objective 3 is to ingest simulated CYGNSS data into the WRF model in order to perform observing system simulation experiments (OSSEs). These will be used to test and quantify the potential beneficial effects provided by CYGNSS, particularly for characterizing the physical processes driving convective organization and upscale development during the initiation and development of the MJO. The proposed research is ideal for answering important

  5. Evaluation of convection-permitting model simulations of cloud populations associated with the Madden-Julian Oscillation using data collected during the AMIE/DYNAMO field campaign

    SciTech Connect

    Hagos, Samson M.; Feng, Zhe; Burleyson, Casey D.; Lim, Kyo-Sun; Long, Charles N.; Wu, Di; Thompson, Gregory

    2014-11-12

    Regional cloud permitting model simulations of cloud populations observed during the 2011 ARM Madden Julian Oscillation Investigation Experiment/ Dynamics of Madden-Julian Experiment (AMIE/DYNAMO) field campaign are evaluated against radar and ship-based measurements. Sensitivity of model simulated surface rain rate statistics to parameters and parameterization of hydrometeor sizes in five commonly used WRF microphysics schemes are examined. It is shown that at 2 km grid spacing, the model generally overestimates rain rate from large and deep convective cores. Sensitivity runs involving variation of parameters that affect rain drop or ice particle size distribution (more aggressive break-up process etc) generally reduce the bias in rain-rate and boundary layer temperature statistics as the smaller particles become more vulnerable to evaporation. Furthermore significant improvement in the convective rain-rate statistics is observed when the horizontal grid-spacing is reduced to 1 km and 0.5 km, while it is worsened when run at 4 km grid spacing as increased turbulence enhances evaporation. The results suggest modulation of evaporation processes, through parameterization of turbulent mixing and break-up of hydrometeors may provide a potential avenue for correcting cloud statistics and associated boundary layer temperature biases in regional and global cloud permitting model simulations.

  6. Evaluation of convection-permitting model simulations of cloud populations associated with the Madden-Julian Oscillation using data collected during the AMIE/DYNAMO field campaign

    NASA Astrophysics Data System (ADS)

    Hagos, Samson; Feng, Zhe; Burleyson, Casey D.; Lim, Kyo-Sun Sunny; Long, Charles N.; Wu, Di; Thompson, Greg

    2014-11-01

    Regional convection-permitting model simulations of cloud populations observed during the 2011 Atmospheric Radiation Measurement (ARM) Madden-Julian Oscillation Investigation Experiment/Dynamics of the Madden-Julian Oscillation Experiment (AMIE/DYNAMO) field campaign are evaluated against ground-based radar and ship-based observations. Sensitivity of model simulated reflectivity, surface rain rate, and cold pool statistics to variations of raindrop breakup/self-collection parameters in four state-of-the-art two-moment bulk microphysics schemes in the Weather Research and Forecasting (WRF) model is examined. The model simulations generally overestimate reflectivity from large and deep convective cells, and underestimate stratiform rain and the frequency of cold pools. In the sensitivity experiments, introduction of more aggressive raindrop breakup or decreasing the self-collection efficiency increases the cold pool occurrence frequency in all of the simulations, and slightly reduces the reflectivity and precipitation statistics bias in some schemes but has little effect on the overall mean surface precipitation. Both the radar observations and model simulations of cloud populations show an approximate power law relationship between convective echo-top height and equivalent convective cell radius.

  7. Moist static energy and the Madden-Julian oscillation: Understanding initiation, maintenance and propagation through the application of novel diagnostics

    NASA Astrophysics Data System (ADS)

    Wolding, Brandon

    As the dominant mode of tropical intraseasonal variability, the Madden-Julian Oscillation (MJO) has enormous societal impacts. Despite four decades of research motivated by these impacts, the processes that drive the initiation, maintenance and propagation of the MJO are still poorly understood. The development of large scale moisture anomalies plays an important role in many recent theories of the MJO, including moisture mode theory. This study identifies processes that support the development, maintenance and propagation of moisture anomalies associated with the MJO. A new set of objective MJO diagnostics, obtained as an extension of CEOF analysis, are introduced. These diagnostics provide useful measures of previously overlooked information yielded by CEOF analysis, including an objective measure that allows geographically disparate locations to be compared and contrasted throughout a reference MJO lifecycle. Compositing techniques based on this measure are applied to the MJO in an attempt to determine key physical processes affecting the MSE budget, identify prominent geographical variability of these processes, and highlight changes in the mean state winds and moisture field that explain this variability. The MSE budget reveals that variations in MSE associated with the MJO are largely the result of variations in column integrated moisture content (~90%), the majority of which occur between 850-500 hPa (~75%). Easterly(westerly) low level wind anomalies to the east(west) of the MJO result in a reduction(enhancement) of drying due to horizontal advection, which is only partially offset by a reduction(enhancement) of surface latent heat flux. In the deep tropics (5°N-5°S) of the eastern hemisphere, anomalous horizontal advection is primarily the result of the anomalous winds acting on the mean state moisture gradient. Over the broader tropics (15°N-15°S), the anomalous horizontal advection appears to result primarily from the modulation of synoptic scale

  8. The 'Vertical Structure and Diabatic Processes of the Madden-Julian Oscillation' model evaluation project: Overview and key results (Invited)

    NASA Astrophysics Data System (ADS)

    Klingaman, N. P.; Jiang, X.; Xavier, P.; Petch, J.; Waliser, D. E.; Woolnough, S.

    2013-12-01

    The Madden-Julian oscillation (MJO) is the dominant mode of tropical sub-seasonal (30-60 day) variability. By modulating regional monsoon circulation and precipitation, interacting with ENSO and influences modes of extra-tropical variability (e.g., the NAO), the MJO provides a key source of weekly and monthly predictability globally. Despite this, most weather and climate models exhibit large biases in their simulations of the MJO. We will introduce a model evaluation project, endorsed by YoTC and GASS, designed to identify and reduce sources of error in the models' MJO representations. A key advantage of this project over previous intercomparisons is that temperature, moisture and momentum tendencies have been requested from all sub-grid parameterization schemes. This allows detailed analysis of the links between biases in MJO activity and biases in the vertical profiles of diabatic heating, moistening and momentum. The project comprises three components: 20-year simulations, from which the overall level of MJO activity can be assessed; serial 2-day hindcasts of two strong events in winter 2009-2010, in which the behavior of model parameterizations can be evaluated close to the initial, observed state; and serial 20-day hindcasts of the same two MJO events, which bridge the gap between the other two components by permitting analysis of the degradation of the simulated MJO from the initial state towards the model's climatology. Analysis of the 20-year simulations suggests that many proposed process-oriented MJO metrics, such as the relationship between precipitation and the vertical structure of relative humidity, do not sufficiently distinguish between those models that simulate the MJO well and those that simulate it poorly. It is assumed that the processes described by these metrics are necessary, but not sufficient, for an adequate simulation of the MJO in GCMs. Analysis of the 2-day hindcasts demonstrates that models develop substantial biases in upper

  9. [Julian Kosiński (1833-1914)--especially meritorious surgeon for the development of otorhinolaryngology. His achievements in therapy of ear, nose, throat and borderland diseases].

    PubMed

    Kierzek, Andrzej

    2008-01-01

    The professional and scientific activities of Julian Kosiński (1833-1914), an eminent Varsovian surgeon, his thorough medical education in various European countries is shortly outlined. He was the versatile surgeon, the head of Surgical Clinic in the Main School and in the Imperial Warsaw University. Kosiński was the creator of "Varsovian surgical school". Kosiński's successful surgical treatment of otorhinopharyngeal diseases and the borderland (such as auricle's fibroma, keloid and periauricular atheroma, carcinomas of nasi and other parts of face, sarcomas of nasopharyngeal cavity and pharynx and maxillary sinus, syphilis of face, tuberculous ulceration of tongue, osteomas of palate and pharynx, foreign bodies of oesophagus, inflammations of parotid gland and other) are described in some more detail. The surgical therapy in that region such as plastic reconstruction of face, oesophagotomy was performed according to contemporary world-wide standards. PMID:18637452

  10. The self-organizing map, a new approach to apprehend the Madden-Julian Oscillation influence on the intraseasonal variability of rainfall in the southern African region

    NASA Astrophysics Data System (ADS)

    Oettli, Pascal; Tozuka, Tomoki; Izumo, Takeshi; Engelbrecht, Francois A.; Yamagata, Toshio

    2014-09-01

    The Madden-Julian Oscillation (MJO) is the major mode of intraseasonal variability (30-60 days) in the tropics, having large rainfall impacts globally, and possibly on southern Africa. However, the latter impact is not well understood and needs to be further explored. The life cycle of the MJO, known to be asymmetric, has been nevertheless analyzed usually through methods constrained by both linearity and orthogonality, such as empirical orthogonal function analysis. Here we explore a non-linear classification method, the self-organizing map (SOM), a type of artificial neural network used to produce a low-dimensional representation of high-dimensional datasets, to capture more accurately the life cycle of the MJO and its global impacts. The classification is applied on intraseasonal anomalies of outgoing longwave radiation within the tropical region over the 1980-2009 period. Using the SOM to describe the MJO is a new approach, complimentary to the usual real-time multivariate MJO index. It efficiently captures this propagative phenomenon and its seasonality, and is shown to provide additional temporal and spatial information on MJO activity. For each node, the subtropical convection is analyzed, with a particular focus on the southern Africa region. Results show that the convection activity over the central tropical Indian Ocean is a key factor influencing the intraseasonal convective activity over the southern African region. Enhanced (suppressed) convection over the central Indian Ocean tends to suppress (enhance) convection over the southern African region with a 10-day lag by modulating the moisture transport.

  11. A Critical Role of Dry Air Intrusion for Propagation of the Madden-Julian Oscillation Based on Multi-model Simulations

    NASA Astrophysics Data System (ADS)

    Jiang, X.

    2015-12-01

    The Madden-Julian Oscillation (MJO) exerts pronounced influences on global climate and extreme weather systems. Our current general circulation models (GCMs), however, exhibit rather limited capability in representing this prominent tropical variability mode. Meanwhile, fundamental physics of the MJO are still elusive. In this presentation, by analyzing 27 climate models that participated in the WCRP-WWRP/THORPEX YOTC MJO Task Force and GEWEX GASS global MJO model inter-comparison project, key processes responsible for realistic MJO simulations are explored based on budget analysis of moist static energy (MSE). Results suggest that horizontal advection of MSE, particularly the dry air intrusion from the west of the MJO convection, plays a crucial role for realistic eastward propagation of the MJO in GCM simulations. Due to model deficiencies in simulating both the MJO circulation and spatial distribution of background MSE, the horizontal advection of MSE is greatly underestimated in the poor MJO models, and largely offset by effects from radiative and surface fluxes, leading to rather weak eastward or even westward propagation of MJO convection in those models.

  12. Overview of Proposal on High Resolution Climate Model Simulations of Recent Hurricane and Typhoon Activity: The Impact of SSTs and the Madden Julian Oscillation

    NASA Technical Reports Server (NTRS)

    Schubert, Siegfried; Kang, In-Sik; Reale, Oreste

    2009-01-01

    This talk gives an update on the progress and further plans for a coordinated project to carry out and analyze high-resolution simulations of tropical storm activity with a number of state-of-the-art global climate models. Issues addressed include, the mechanisms by which SSTs control tropical storm. activity on inter-annual and longer time scales, the modulation of that activity by the Madden Julian Oscillation on sub-seasonal time scales, as well as the sensitivity of the results to model formulation. The project also encourages companion coarser resolution runs to help assess resolution dependence, and. the ability of the models to capture the large-scale and long-terra changes in the parameters important for hurricane development. Addressing the above science questions is critical to understanding the nature of the variability of the Asian-Australian monsoon and its regional impacts, and thus CLIVAR RAMP fully endorses the proposed tropical storm simulation activity. The project is open to all interested organizations and investigators, and the results from the runs will be shared among the participants, as well as made available to the broader scientific community for analysis.

  13. The vertical structure of diabatic heating associated with the Madden-Julian oscillation simulated by the Goddard Laboratory for Atmospheres climate model

    NASA Technical Reports Server (NTRS)

    Chen, Tsing-Chang; Yen, Ming-Cheng; Pfaendtner, James; Sud, Y. C.

    1993-01-01

    The diabatic heating structure of the nine-layer Goddard Laboratory for Atmospheres model of the Madden-Julian oscillation (MJO) is illustrated with composite charts made for those times when this low-frequency mode reaches its maximum and minimum amplitudes. These composite charts compare the vertically integrated diabatic heating with potential functions, the vertical distribution of diabatic heating with the east-west mass flux function in the tropics, and the vertical profiles of diabatic heating at the centers of maximum and minimum MJO amplitude. Three interesting features of the model MJO's diabatic heating are revealed: (1) the maximum heating rate of this low-frequency mode is located over the Asian monsoon region and its amplitude is about a half of the maximum value of the seasonal mean heating rate in this region, (2) the vertical diabatic heating rate profile has a maximum at 500 mbar and resembles the seasonal mean total heating profile, and (3) the total diabatic heating is for the most part composed of the latent heat released by cumulus convection.

  14. The Madden-Julian Oscillation in the National Center for Atmospheric Research Community Atmospheric Model-2 with the Tiedtke Convective Scheme

    SciTech Connect

    Liu, P; Wang, B; Sperber, K R; Li, T; Meehl, G A

    2004-07-26

    The boreal winter Madden-Julian oscillation (MJO) remains very weak and irregular in structure in the National Center for Atmospheric Research (NCAR) Community Atmosphere Model version 2 (CAM2) as in its direct predecessor, the Community Climate Model version 3 (CCM3). The standard version of CAM2 uses the deep convective scheme of Zhang and McFarlane (1995), as in CCM3, with the closure dependent on convective available potential energy (CAPE). Here, sensitivity tests using several versions of the Tiedtke (1989) convective scheme are conducted. Typically, the Tiedtke convection scheme gives an improved mean state, intraseasonal variability, space-time power spectra, and eastward propagation compared to the standard version of the model. Coherent eastward propagation of MJO related precipitation is also much improved, particularly over the Indian-western Pacific Oceans. Sensitivity experiments show that enhanced downdrafts in the Tiedtke scheme reduces the amplitude of the MJO but to a lesser extent than when this scheme is closed on CAPE to represent deep convections. A composite life cycle of the model MJO indicates that over the Indian Ocean wind induced surface heat exchange functions, while over the western/central Pacific Ocean aspects of frictional moisture convergence are evident in the maintenance and eastward propagation of the oscillation.

  15. Rap and Orality in a Post-NCLB/ALEC World

    ERIC Educational Resources Information Center

    Paul, Dierdre Glenn

    2013-01-01

    Rigid foci on accountability, accreditation, and customer service pose significant challenges for literacy educators today. The most consequential identified as the snuffing out of scholastic innovation and erosion of academic freedom. This article recounts a recent experience that occurred while the author prepared a lesson for an undergraduate…

  16. Follow up of premature babies treated with artificial surfactant (ALEC).

    PubMed Central

    Morley, C J; Morley, R

    1990-01-01

    Of 235 survivors who had taken part in a randomised trial of artificial surfactant and who were born in Cambridge, follow up information was available for 231 (98%) infants. In 12 cases information came from local doctors; all others were assessed at 9 and 18 months (n = 212) or 9 months only (n = 7). There was no difference between those who had been treated with surfactant and control babies in the incidence of neurological impairment, mental impairment, respiratory infections, allergies, or hospital admissions up to 18 months after full term. In those born before 30 weeks' gestation (where surfactant most improves survival) the number of surviving randomised children who were normal was 35 of 61 in the treated group (57%) compared with 25 of 61 in the control group (41%). Improved neonatal survival after prophylactic surfactant treatment is not associated with an increased incidence of neurodevelopmental impairment. PMID:2201266

  17. Simulation of streamflow and suspended-sediment concentrations and loads in the lower Nueces River watershed, downstream from Lake Corpus Christi to the Nueces Estuary, South Texas, 1958-2008

    USGS Publications Warehouse

    Ockerman, Darwin J.; Heitmuller, Franklin T.

    2010-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Army Corps of Engineers-Fort Worth District, City of Corpus Christi, Guadalupe-Blanco River Authority, San Antonio River Authority, and San Antonio Water System, developed, calibrated, and tested a Hydrological Simulation Program ? FORTRAN (HSPF) watershed model to simulate streamflow and suspended-sediment concentrations and loads during 1958-2008 in the lower Nueces River watershed, downstream from Lake Corpus Christi to the Nueces Estuary in South Texas. Data available to simulate suspended-sediment concentrations and loads consisted of historical sediment data collected during 1942-82 in the study area and suspended-sediment concentration data collected periodically by the USGS during 2006-07 at three USGS streamflow-gaging stations, Nueces River near Mathis, Nueces River at Bluntzer, and Nueces River at Calallen. The Nueces River near Mathis station is downstream from Wesley E. Seale Dam, completed in 1958 to impound Lake Corpus Christi. Suspended-sediment data collected before and after completion of Wesley E. Seale Dam provide insights to the effects of the dam and reservoir on suspended-sediment loads transported by the lower Nueces River from downstream of the dam to the Nueces Estuary. Annual suspended-sediment loads at a site near the Nueces River at Mathis station were considerably lower, for a given annual mean discharge, after the dam was completed than before the dam was completed. Most of the suspended sediment transported by the Nueces River downstream from Wesley E. Seale Dam occurred during high-flow releases from the dam or during floods. During October 1964-September 1971, about 532,000 tons of suspended sediment were transported by the Nueces River near Mathis. Of this amount, about 473,000 tons, or about 89 percent, were transported by large runoff events (mean streamflow exceeding 1,000 cubic feet per second). To develop the watershed model to simulate suspended

  18. Evaluation of the impacts of the Madden-Julian Oscillation on rainfall and hurricanes in Central and South America and the Atlantic Ocean using ICI-RAFT

    NASA Astrophysics Data System (ADS)

    Giovannettone, J. P.

    2013-12-01

    Based on the method of Regional Frequency Analysis (RFA) and L-moments (Hosking & Wallis, 1997), a tool was developed to estimate the frequency/intensity of a rainfall event of a particular duration using ground-based rainfall observations. Some of the code used to develop this tool was taken from the FORTRAN code provided by Hosking & Wallis and rewritten in Visual Basic 2010. This tool was developed at the International Center for Integrated Water Resources Management (ICIWaRM) and is referred to as the ICIWaRM Regional Analysis of Frequency Tool (ICI-RAFT) (Giovannettone & Wright, 2012). In order to study the effectiveness of ICI-RAFT, three case studies were selected for the analysis. The studies take place in selected regions within Argentina, Nicaragua, and Venezuela. Rainfall data were provided at locations throughout each country; total rainfall for specific periods were computed and analyzed with respect to several global climate indices using lag times ranging from 1 to 6 months. Each analysis attempts to identify a global climate index capable of predicting above or below average rainfall several months in advance, qualitatively and using an equation that is developed. The index that had the greatest impact was the MJO (Madden-Julian Oscillation), which is the focus of the current study. The MJO is considered the largest element of intra-seasonal (30 - 90 days) variability in the tropical atmosphere and, unlike other indices, is characterized by the eastward propagation of large areas of convective anomalies near the equator, propagating from the Indian Ocean east into the Pacific Ocean. The anomalies are monitored globally using ten different indices located on lines of longitude near the equator, with seven in the eastern hemisphere and three in the western hemisphere. It has been found in previous studies that the MJO is linked to summer rainfall in Southeast China (Zhang et al., 2009) and southern Africa (Pohl et al., 2007) and to rainfall patterns

  19. Effects of moisture feedback in a frictional coupled Kelvin-Rossby wave model and implication in the Madden-Julian oscillation dynamics

    NASA Astrophysics Data System (ADS)

    Liu, Fei; Wang, Bin

    2016-03-01

    The authors extend the original frictional wave dynamics and implement the moisture feedback (MF) to explore the effects of planetary boundary layer (PBL) process and the MF on the Madden-Julian Oscillation (MJO). This new system develops the original frictional wave dynamics by including the moisture tendency term (or the MF mode), along with a parameterized precipitation based on the Betts-Miller scheme. The linear instability analysis of this model provides solutions to elucidate the behaviors of the "pure" frictional convergence (FC) mode and the "pure" MF mode, respectively, as well as the behaviors of the combined FC-MF mode or the dynamical moisture mode. These results show that without the PBL frictional moisture convergence, the MF mode is nearly stationary and damped. Not only does the PBL frictional feedback make the damping MF mode grow with preferred planetary scale but it also enables the nearly stationary MF mode to move eastward slowly, resulting in an oscillation with a period of 30-90 days. This finding suggests the important role of the frictional feedback in generating eastward propagating unstable modes and selecting the preferred planetary scales. The MF process slows down the eastward-propagating short-wave FC mode by delaying the occurrence of deep convection and by enhancing the Rossby wave component. However, the longest wave (wavenumber one) is insensitive to the MF or the convective adjustment time, indicating that the unstable longest wave is primarily controlled by PBL frictional feedback process. Implications of these theoretical results in MJO simulation in general circulation models are discussed.

  20. Variation of tropical cyclone activity in the South Indian Ocean: El Niño-Southern Oscillation and Madden-Julian Oscillation effects

    NASA Astrophysics Data System (ADS)

    Ho, Chang-Hoi; Kim, Joo-Hong; Jeong, Jee-Hoon; Kim, Hyeong-Seog; Chen, Deliang

    2006-11-01

    The present study examines variation of tropical cyclone (TC) activity in the South Indian Ocean (SIO) during TC seasons (December-March) for the period 1979-2004. The impact of the El Niño-Southern Oscillation and the Madden-Julian Oscillation (MJO) on the variation is revealed through a composite analysis. During El Niño periods TC genesis was shifted westward, enhancing the formation west of 75°E and reducing it east of 75°E. These changes in the genesis correspond to a westward shift of convection. It may be explained by a remote effect on the SIO; that is, the increase in sea surface temperature in the central eastern Pacific alters the Walker circulation and forms an anomalous anticyclonic circulation in the east SIO during El Niño. The spatial difference in TC passages between El Niño and La Niña shows a significant decrease to the southeast of Madagascar but a moderate increase in the central midlatitude SIO, indicating that TCs move farther east during El Niño. This change is possibly due to the anomalous southwesterlies east of Madagascar. Variation of TC activity also depends on various MJO phases: frequent TC passages for phases 2-4 (strong convective activity straddles along the equatorial Indian Ocean) versus infrequent TC passages for other phases. TC tracks tend to be more south oriented in phase 3 compared with those in phases 2 and 4. This is possibly caused by the increased steering northerlies which are a part of the anticyclonic Rossby wave of Gill type in response to the suppressed MJO-related convection in the maritime continent.

  1. Influence of Madden-Julian Oscillation on water budget transported by the Somali low-level jet and the associated Indian summer monsoon rainfall

    NASA Astrophysics Data System (ADS)

    Ordonez, Paulina; Ribera, Pedro; Gallego, David; Pena-Ortiz, Cristina

    2013-10-01

    Recent studies suggest that there is a strong linkage between the moisture uptake over the equatorial area of the Somali low level jet (SLLJ) and the rainfall variability over most of continental India. Additionally, the Madden-Julian Oscillation (MJO) strongly modulates the intraseasonal variability of the Indian summer monsoon rainfall, since the northward propagation of the boreal summer MJO is closely associated with the active and break phases of monsoon rainfall. But a question remains open: is there a relationship between the moisture transported by the SLLJ and the MJO evolution? In this paper, a Lagrangian approach is used to track the evaporation minus precipitation (E - P) evolution along trajectories of particles initially situated over the equatorial region of SLLJ. The impact of the MJO on the water budget transport of the SLLJ is examined by making composites of the obtained (E-P) fields for the different MJO phases. The spatial structures of the boreal summer intraseasonal oscillation are revealed in our results, which strongly suggest that the main responsible for the rainfall variability associated to the MJO in these regions are the changes in the moisture advected by the SLLJ. In order to assess the MJO-SLLJ interaction, an analysis of the total-column mass and the total-column specific humidity transported by the SLLJ during the MJO life cycle is performed. While a systematic difference between air mass advected to India during active and break phases of MJO is not detected, changes in the moisture of particles are found, with wet (dry) anomalies over enhanced (suppressed) convection region. This result implicitly leads to assume air-sea interaction processes.

  2. The response of the equatorial tropospheric ozone to the Madden-Julian Oscillation in TES satellite observations and CAM-chem model simulation

    NASA Astrophysics Data System (ADS)

    Sun, W.; Hess, P.; Tian, B.

    2014-06-01

    The Madden-Julian Oscillation (MJO) is the dominant form of the atmospheric intra-seasonal oscillation, manifested by slow eastward movement (about 5 m s-1) of tropical deep convection. This study investigates the MJO's impact on equatorial tropospheric ozone (10° N-10° S) in satellite observations and chemical transport model (CTM) simulations. For the satellite observations, we analyze the Tropospheric Emission Spectrometer (TES) level-2 ozone profile data for the period of January 2004 to June 2009. For the CTM simulations, we run the Community Atmosphere Model with chemistry (CAM-chem) driven by the GOES-5 analyzed meteorological fields for the same data period as the TES measurements. Our analysis indicates that the behavior of the Total Tropospheric Column (TTC) ozone at the intraseasonal time scale is different from that of the total column ozone, with the signal in the equatorial region comparable with that in the subtropics. The model simulated and satellite measured ozone anomalies agree in their general pattern and amplitude when examined in the vertical cross section (the average spatial correlation coefficient among the 8 phases is 0.63), with an eastward propagation signature at a similar phase speed as the convective anomalies (5 m s-1). The ozone anomalies on the intraseasonal time scale are about five times larger when lightning emissions of NOx are included in the simulation than when they are not. Nevertheless, large-scale advection is the primary driving force for the ozone anomalies associated with the MJO. The variability related to the MJO for ozone reaches up to 47% of the total variability (ranging from daily to interannual), indicating the MJO should be accounted for in simulating ozone perturbations in the tropics.

  3. Modulation of equatorial Pacific westerly/easterly wind events by the Madden-Julian oscillation and convectively-coupled Rossby waves

    NASA Astrophysics Data System (ADS)

    Puy, Martin; Vialard, J.; Lengaigne, M.; Guilyardi, E.

    2016-04-01

    Synoptic wind events in the equatorial Pacific strongly influence the El Niño/Southern Oscillation (ENSO) evolution. This paper characterizes the spatio-temporal distribution of Easterly (EWEs) and Westerly Wind Events (WWEs) and quantifies their relationship with intraseasonal and interannual large-scale climate variability. We unambiguously demonstrate that the Madden-Julian Oscillation (MJO) and Convectively-coupled Rossby Waves (CRW) modulate both WWEs and EWEs occurrence probability. 86 % of WWEs occur within convective MJO and/or CRW phases and 83 % of EWEs occur within the suppressed phase of MJO and/or CRW. 41 % of WWEs and 26 % of EWEs are in particular associated with the combined occurrence of a CRW/MJO, far more than what would be expected from a random distribution (3 %). Wind events embedded within MJO phases also have a stronger impact on the ocean, due to a tendency to have a larger amplitude, zonal extent and longer duration. These findings are robust irrespective of the wind events and MJO/CRW detection methods. While WWEs and EWEs behave rather symmetrically with respect to MJO/CRW activity, the impact of ENSO on wind events is asymmetrical. The WWEs occurrence probability indeed increases when the warm pool is displaced eastward during El Niño events, an increase that can partly be related to interannual modulation of the MJO/CRW activity in the western Pacific. On the other hand, the EWEs modulation by ENSO is less robust, and strongly depends on the wind event detection method. The consequences of these results for ENSO predictability are discussed.

  4. Comparison of Moist Static Energy and Budget between the GCM-Simulated Madden–Julian Oscillation and Observations over the Indian Ocean and Western Pacific

    SciTech Connect

    Wu, Xiaoqing; Deng, Liping

    2013-07-01

    The moist static energy (MSE) anomalies and MSE budget associated with the Madden–Julian oscillation (MJO) simulated in the Iowa State University General Circulation Model (ISUGCM) over the Indian and Pacific Oceans are compared with observations. Different phase relationships between MJO 850-hPa zonal wind, precipitation, and surface latent heat flux are simulated over the Indian Ocean and western Pacific, which are greatly influenced by the convection closure, trigger conditions, and convective momentum transport (CMT). The moist static energy builds up from the lower troposphere 15–20 days before the peak of MJO precipitation, and reaches the maximum in the middle troposphere (500–600 hPa) near the peak of MJO precipitation. The gradual lower-tropospheric heating and moistening and the upward transport of moist static energy are important aspects of MJO events, which are documented in observational studies but poorly simulated in most GCMs. The trigger conditions for deep convection, obtained from the year-long cloud resolving model (CRM) simulations, contribute to the striking difference between ISUGCM simulations with the original and modified convection schemes and play the major role in the improved MJO simulation in ISUGCM. Additionally, the budget analysis with the ISUGCM simulations shows the increase in MJO MSE is in phase with the horizontal advection of MSE over the western Pacific, while out of phase with the horizontal advection of MSE over the Indian Ocean. However, the NCEP analysis shows that the tendency of MJO MSE is in phase with the horizontal advection of MSE over both oceans.

  5. Multi-Reanalysis Comparison of Variability in Analysis Increment of Column-Integrated Water Vapor Associated with Madden-Julian Oscillation

    NASA Astrophysics Data System (ADS)

    Yokoi, S.

    2014-12-01

    This study conducts a comparison of three reanalysis products (JRA-55, JRA-25, and ERA-Interim) in representation of Madden-Julian Oscillation (MJO), focusing on column-integrated water vapor (CWV) that is considered as an essential variable for discussing MJO dynamics. Besides the analysis fields of CWV, which exhibit spatio-temporal distributions that are quite similar to satellite observations, CWV tendency simulated by forecast models and analysis increment calculated by data assimilation are examined. For JRA-55, it is revealed that, while its forecast model is able to simulate eastward propagation of the CWV anomaly, it tends to weaken the amplitude, and data assimilation process sustains the amplitude. The multi-reanalysis comparison of the analysis increment further reveals that this weakening bias is probably caused by excessively weak cloud-radiative feedback represented by the model. This bias in the feedback strength makes anomalous moisture supply by the vertical advection term in the CWV budget equation too insensitive to precipitation anomaly, resulting in reduction of the amplitude of CWV anomaly. ERA-Interim has a nearly opposite feature; the forecast model represents excessively strong feedback and unrealistically strengthens the amplitude, while the data assimilation weakens it. These results imply the necessity of accurate representation of the cloud-radiative feedback strength for a short-term MJO forecast, and may be evidence to support the argument that this feedback is essential for the existence of MJO. Furthermore, this study demonstrates that the multi-reanalysis comparison of the analysis increment will provide useful information for identifying model biases and, potentially, for estimating parameters that are difficult to estimate solely from observation data, such as gross moist stability.

  6. MM5 Modeling of the Madden-Julian Oscillation in the Indian and West Pacific Oceans: Model Description and Control Run Results

    SciTech Connect

    Gustafson, William I.; Weare, B. C.

    2004-03-01

    A new methodology to study the Madden-Julian Oscillation (MJO) is introduced. While previous MJO studies typically have involved highly simplified mathematical models or general circulation models, this new approach seeks to reproduce the MJO using a regional model with prescribed boundary conditions. This paper reports initial control run results for this methodology using the Fifth Generation Pennsylvania State/NCAR Mesoscale Model (MM5) for a domain extending from the western Indian Ocean to the Dateline. The control run boundaries are forced using the NCEP/NCAR Reanalysis (NRA) data set for a 24 month time period. The climatology for the 24 month period is examined to establish the robustness of the MM5 model for this region. Results indicate good agreement in the mean winds between the model and the forcing data set. The primary differences are an easterly bias at 850 hPa and altered flow patterns in the Indian monsoon region. Mean OLR results are good for the model interior with larger discrepancies near the western and eastern boundaries. These discrepancies lead to a reversal of the OLR gradient along the equator. Thirty to seventy day bandpassed data is examined to determine how MM5 reproduces the MJO. The modeled and comparison data 30–70 day zonal wind and OLR have similar MJO periodicities, exhibit eastward propagation, and possess the observed seasonal character and vertical structure of the MJO. The “Matthews EOF” technique reveals good similarity between the model and observed OLR. Analysis of vertical profiles of 30-70 day zonal wind reveals lower tropospheric winds blow in the opposite direction of upper level winds for both the model and NRA. Vertical profiles of 30-70 day moist static energy exhibit a peak near the top of the boundary layer. Differences between the model simulated and observed MJO events are a tendency for the OLR to be relatively noisy and for peak OLR intensity to occur in the west Indian Ocean in the model as opposed to

  7. MM5 Modeling of the Madden Julian Oscillation in the Indian and West Pacific Oceans: Implications of 30 70-Day Boundary Effects on MJO Development.

    NASA Astrophysics Data System (ADS)

    Gustafson, William I., Jr.; Weare, Bryan C.

    2004-03-01

    The results of an experiment designed to isolate the initiation phase of the Madden Julian oscillation (MJO) from 30 70-day boundary effects is presented. The technique used to accomplish this involves employing the fifth-generation Pennsylvania State University National Center for Atmospheric Research (PSU NCAR) Mesoscale Model (MM5), as first presented in the companion paper to this paper. Two runs, each 2 yr long, are integrated forward from 1 June 1990. The first run, called the control, uses the unmodified National Centers for Environmental Prediction (NCEP) NCAR reanalysis (NRA) dataset for boundary conditions. The second run, called the notched, uses the same NRA dataset for the boundary conditions, with the exception that all signals with periodicities in the 30 70-day range have been removed. Any signals in the 30 70-day range subsequently generated by the notched run are then solely due to signals generated from within the model domain or from signals entering through the domain boundaries with frequencies outside of the MJO band. Comparisons between 2-yr means from each run indicate that filtering the boundaries does not significantly modify the model climatology. The mean wind structure, thermodynamic state, and outgoing longwave radiation (OLR) are almost identical in the control and notched runs. A 30 70-day bandpass filter is used to isolate MJO-like signals in the runs. Comparisons of 30 70-day bandpassed zonal wind, moist static energy (MSE), and OLR reveal that the notched run develops many of the expected characteristics of MJO episodes, but with a weaker signal. Large-scale, organized structures develop that possess seasonal shifts in amplitude, mirroring observed MJO activity, have opposite wind directions in the upper and lower troposphere, and propagate eastward during most strong episodes. The results suggest that neither remnants from previous MJO episodes nor extratropical feedbacks within the MJO time band are necessary for MJO initiation

  8. H. Julian Allen: An Appreciation

    NASA Astrophysics Data System (ADS)

    Vincenti, Walter G.; Boyd, John W.; Bugos, Glenn E.

    2007-01-01

    Harvey Allen is best known as the genius behind the blunt-body concept, published in 1953, which enables spacecraft to return safely home through Earth's dense atmosphere. He was also an extraordinary research leader, who led a world-class research program in hypersonics at the NACA Ames Aeronautical Laboratory. This paper reviews his career as one of America's leading theorists and experimenters, including his engineering education at Stanford, his work on the inverse problem of calculating the airfoil profile to obtain a desired pressure distribution, his hand in constructing wind tunnels and experimental facilities at Ames, and his pioneering and wide-ranging work on atmospheric re-entry. It concludes with an appreciation of his uniquely inspirational style of research management, and of his magnetic personality.

  9. Modelling the Madden Julian Oscillation

    SciTech Connect

    Slingo, J M; Inness, P M; Sperber, K R

    2004-05-21

    The MJO has long been an aspect of the global climate that has provided a tough test for the climate modelling community. Since the 1980s there have been numerous studies of the simulation of the MJO in atmospheric general circulation models (GCMs), ranging from Hayashi and Golder (1986, 1988) and Lau and Lau (1986), through to more recent studies such as Wang and Schlesinger (1999) and Wu et al. (2002). Of course, attempts to reproduce the MJO in climate models have proceeded in parallel with developments in our understanding of what the MJO is and what drives it. In fact, many advances in understanding the MJO have come through modeling studies. In particular, failure of climate models to simulate various aspects of the MJO has prompted investigations into the mechanisms that are important to its initiation and maintenance, leading to improvements both in our understanding of, and ability to simulate, the MJO. The initial focus of this chapter will be on modeling the MJO during northern winter, when it is characterized as a predominantly eastward propagating mode and is most readily seen in observations. Aspects of the simulation of the MJO will be discussed in the context of its sensitivity to the formulation of the atmospheric model, and the increasing evidence that it may be a coupled ocean-atmosphere phenomenon. Later, we will discuss the challenges regarding the simulation of boreal summer intraseasonal variability, which is more complex since it is a combination of the eastward propagating MJO and the northward propagation of the tropical convergence zone. Finally some concluding remarks on future directions in modeling the MJO and its relationship with other timescales of variability in the tropics will be made.

  10. On the roles of the northeast cold surge, the Borneo vortex, the Madden-Julian Oscillation, and the Indian Ocean Dipole during the extreme 2006/2007 flood in southern Peninsular Malaysia

    NASA Astrophysics Data System (ADS)

    Tangang, Fredolin T.; Juneng, Liew; Salimun, Ester; Vinayachandran, P. N.; Seng, Yap Kok; Reason, C. J. C.; Behera, S. K.; Yasunari, T.

    2008-05-01

    The mid-December 2006 to late January 2007 flood in southern Peninsular Malaysia was the worst flood in a century and was caused by three extreme precipitation episodes. These extreme precipitation events were mainly associated with strong northeasterly winds over the South China Sea. In all cases, the northeasterlies penetrated anomalously far south and followed almost a straight trajectory. The elevated terrain over Sumatra and southern Peninsular Malaysia caused low-level convergence. The strong easterly winds near Java associated with the Rossby wave-type response to Madden-Julian Oscillation (MJO) inhibited the counter-clockwise turning of the northeasterlies and the formation of the Borneo vortex, which, in turn, enhanced the low-level convergence over the region. The abrupt termination of the Indian Ocean Dipole (IOD) in December 2006 played a secondary role as warmer equatorial Indian Ocean helped in the MJO formation.

  11. Obituary: Thomas Julian Ahrens (1936-2010)

    NASA Astrophysics Data System (ADS)

    Jeanloz, Raymond; Asimow, Paul

    2011-12-01

    Thomas J. Ahrens, a leader in the use of shock waves to study planetary interiors and impact phenomena, died at his home in Pasadena, California on November 24, 2010, at the age of 74. He was the California Institute of Technology's Fletcher Jones Professor of Geophysics, formally emeritus since 2005 but professionally active to the end. Tom was a pioneer in experimental and numerical studies of the effects of hypervelocity impact, arguably the most important geophysical process in the formation, growth and - in many cases - surface evolution of planets. As a professor at Caltech, he established the foremost university laboratory for shock wave experiments, where students and research associates from around the world pursued basic research in geophysics, planetary science and other disciplines. Previously, high-pressure shock experiments were primarily conducted in national laboratories, where they were initially associated with development of nuclear weapons. The shock wave laboratory at Caltech was noted for key measurements addressing major questions in planetary geophysics. Equation-of-state studies on silicate melts showed that magma deep in Earth's mantle could be denser than the coexisting crystals, implying downward transport of melts (and associated heat) rather than the upward eruption of lavas observed in volcanic regions at Earth's surface. Shock-melting experiments on iron at pressures of Earth's core provide a crucial constraint on the temperature at the center of our planet. And studies of hydrous, carbonate and sulphate minerals under shock compression document how climate-altering molecules can be released by major impacts, such as the K/T event associated with the most recent mass extinction of biota in Earth history. In addition, Tom was a leader in numerical simulation of cratering, bringing the most recent laboratory measurements into the modeling of planetary impacts. Tom's training was in geophysics and applied experimental physics, as exemplified by the ultrasonic wave-velocity measurements of his Ph.D. research at Rensselaer Polytechnic Institute (geophysics Ph.D. in 1962, following a B.S. in geology and geophysics from Massachusetts Institute of Technology in 1957, and M.S. in geophysics from Caltech in 1958). He served in the U.S. Army (1959-60) and was employed at Stanford Research Institute (1962-67), where he conducted shock wave experiments, before joining the faculty at Caltech in 1967. With such a broad background, Tom combined condensed-matter physics, continuum mechanics, petrology and seismology, for instance in characterizing polymorphic phase transformations in Earth's mantle (1967 J. Geophys. Res. Paper with Y. Syono); using shock wave measurements to interpret seismological data on Earth's deep interior (1969 Rev. Geophysics paper with D. L. Anderson and A. E. Ringwood); modeling geodynamic effects of phase-transition kinetics (1975 Rev. Geophysics paper with G. Shubert); characterizing the effects of gravity and crustal strength on crater formation (1981 Rev. Geophysics paper with J. D. O'Keefe); and quantifying impact erosion of terrestrial planetary atmospheres (1993 Annual Review of Earth and Planetary Sciences). The span of his science was also reflected in collaborations with - among others - Paul D. Asimow, George R. Rossman and Edward M. Stolper at Caltech, as well as Arthur C. Mitchell and William J. Nellis at Lawrence Livermore National Laboratory. His accomplishments included conducting the first shock-wave experiments on lunar samples and solid hydrogen; measuring the first absorption spectra of minerals under shock loading; discovering major phase changes in CaO, FeO, KAlSi3O8, and KFeS2; measuring shock temperatures in silicates, metals, and oxides; conducting the first planetary cratering calculations for mass of melted and vaporized material, and mass and energy of ejecta as a function of planetary escape velocity; experimentally documenting shock vaporization on volatile-bearing minerals, and applying the results to understanding the formation of oceans and atmospheres; conducting the first dynamic-compression experiments on molten silicates, with applications to characterizing the maximum depth of volcanism on terrestrial planets, as well as the crystallization sequence of magma oceans; performing the first thermodynamic calculations delineating the impact-shock conditions for melting and vaporization of planetary materials; carrying out the first smoothed particle hydrodynamic calculations to investigate energy partitioning upon impact in self-gravitating planetary systems; and conducting the first quantitative tensile failure studies for brittle media, relating crack-density to elastic velocity deficits and the onset of damage. Tom was also Co-Investigator on the NASA Cosmic Dust Analyzer Experiment, and the NASA/ESA Cassini Mission to Saturn. Honors included the AGU Hess Medal, Geological Society of America Day Medal, Meteoritical Society Barringer Medal, APS Shock Compression of Condensed Matter' Topical Groups's Duvall Medal and AAAS Newcomb-Cleveland Prize. He had been President of AGU's Tectonophysics Section, Editor of Journal of Geophysical Research, founding member of both the Mineral and Rock Physics and Study of Earth's Deep Interior focus groups, and Editor - more like key driving force - for AGU's Handbook of Physical Constants. He was a fellow of the AGU, American Academy of Arts and Sciences, American Association for the Advancement of Science, and Geochemical Society; and member of the U.S. National Academy of Sciences, as well as Foreign Associate of the Russian Academy of Sciences. Main-belt asteroid 4739 Tomahrens (1985 TH1) was named after him. Tom made it clear, however, that it was his students (more than 30), research associates (15 or more) and many collaborators who were the real mark of success. No doubt driven by the need to sustain a major, expensive research facility, as well as to satisfy an inner drive, he maintained a daunting work schedule - including evenings, weekends and holidays - that challenged and stimulated so many around him, perhaps even frightening or frustrating some. He could play as hard as he worked, enjoying sailing, skiing and other outdoor activities over the years.

  12. Obituary: Thomas Julian Ahrens (1936-2010)

    NASA Astrophysics Data System (ADS)

    Jeanloz, Raymond; Asimow, Paul

    2011-12-01

    Thomas J. Ahrens, a leader in the use of shock waves to study planetary interiors and impact phenomena, died at his home in Pasadena, California on November 24, 2010, at the age of 74. He was the California Institute of Technology's Fletcher Jones Professor of Geophysics, formally emeritus since 2005 but professionally active to the end. Tom was a pioneer in experimental and numerical studies of the effects of hypervelocity impact, arguably the most important geophysical process in the formation, growth and - in many cases - surface evolution of planets. As a professor at Caltech, he established the foremost university laboratory for shock wave experiments, where students and research associates from around the world pursued basic research in geophysics, planetary science and other disciplines. Previously, high-pressure shock experiments were primarily conducted in national laboratories, where they were initially associated with development of nuclear weapons. The shock wave laboratory at Caltech was noted for key measurements addressing major questions in planetary geophysics. Equation-of-state studies on silicate melts showed that magma deep in Earth's mantle could be denser than the coexisting crystals, implying downward transport of melts (and associated heat) rather than the upward eruption of lavas observed in volcanic regions at Earth's surface. Shock-melting experiments on iron at pressures of Earth's core provide a crucial constraint on the temperature at the center of our planet. And studies of hydrous, carbonate and sulphate minerals under shock compression document how climate-altering molecules can be released by major impacts, such as the K/T event associated with the most recent mass extinction of biota in Earth history. In addition, Tom was a leader in numerical simulation of cratering, bringing the most recent laboratory measurements into the modeling of planetary impacts. Tom's training was in geophysics and applied experimental physics, as exemplified by the ultrasonic wave-velocity measurements of his Ph.D. research at Rensselaer Polytechnic Institute (geophysics Ph.D. in 1962, following a B.S. in geology and geophysics from Massachusetts Institute of Technology in 1957, and M.S. in geophysics from Caltech in 1958). He served in the U.S. Army (1959-60) and was employed at Stanford Research Institute (1962-67), where he conducted shock wave experiments, before joining the faculty at Caltech in 1967. With such a broad background, Tom combined condensed-matter physics, continuum mechanics, petrology and seismology, for instance in characterizing polymorphic phase transformations in Earth's mantle (1967 J. Geophys. Res. Paper with Y. Syono); using shock wave measurements to interpret seismological data on Earth's deep interior (1969 Rev. Geophysics paper with D. L. Anderson and A. E. Ringwood); modeling geodynamic effects of phase-transition kinetics (1975 Rev. Geophysics paper with G. Shubert); characterizing the effects of gravity and crustal strength on crater formation (1981 Rev. Geophysics paper with J. D. O'Keefe); and quantifying impact erosion of terrestrial planetary atmospheres (1993 Annual Review of Earth and Planetary Sciences). The span of his science was also reflected in collaborations with - among others - Paul D. Asimow, George R. Rossman and Edward M. Stolper at Caltech, as well as Arthur C. Mitchell and William J. Nellis at Lawrence Livermore National Laboratory. His accomplishments included conducting the first shock-wave experiments on lunar samples and solid hydrogen; measuring the first absorption spectra of minerals under shock loading; discovering major phase changes in CaO, FeO, KAlSi3O8, and KFeS2; measuring shock temperatures in silicates, metals, and oxides; conducting the first planetary cratering calculations for mass of melted and vaporized material, and mass and energy of ejecta as a function of planetary escape velocity; experimentally documenting shock vaporization on volatile-bearing minerals, and applying the results to understanding the formation of oceans and atmosph

  13. Observations of the temporal variability in aerosol properties and their relationships to meteorology in the summer monsoonal South China Sea/East Sea: the role of monsoonal flows, the Madden-Julian Oscillation, tropical cyclones, squall lines and cold pools

    NASA Astrophysics Data System (ADS)

    Reid, J. S.; Lagrosas, N. D.; Jonsson, H. H.; Reid, E. A.; Sessions, W. R.; Simpas, J. B.; Uy, S. N.; Boyd, T. J.; Atwood, S. A.; Blake, D. R.; Campbell, J. R.; Cliff, S. S.; Holben, B. N.; Holz, R. E.; Hyer, E. J.; Lynch, P.; Meinardi, S.; Posselt, D. J.; Richardson, K. A.; Salinas, S. V.; Smirnov, A.; Wang, Q.; Yu, L. E.; Zhang, J.

    2014-08-01

    In a joint NRL/Manila Observatory mission, as part of the 7 SouthEast Asian Studies program (7SEAS), a two-week, late September~2011 research cruise in the northern Palawan Archipelago was undertaken to observe the nature of southwest monsoonal aerosol particles in the South China Sea/East Sea (SCS/ES) and Sulu Sea region. Previous analyses suggested this region as a~receptor for biomass burning from Borneo and Sumatra for boundary layer air entering the monsoonal trough. Anthropogenic pollution and biofuel emissions are also ubiquitous, as is heavy shipping traffic. Here, we provide an overview of the regional environment during the cruise, a time series of key aerosol and meteorological parameters, and their interrelationships. Overall, this cruise provides a~narrative of the processes that control regional aerosol loadings and their possible feedbacks with clouds and precipitation. While 2011 was a moderate El Nino/Southern Oscillation (ENSO) La Nina year, higher burning activity and lower precipitation was more typical of neutral conditions. The large-scale aerosol environment was modulated by the Madden-Julian Oscillation (MJO) and its associated tropical cyclone (TC) activity in a manner consistent with the conceptual analysis performed by Reid et al. (2012). Advancement of the MJO from phase 3 to 6 with accompanying cyclogenesis during the cruise period strengthened flow patterns in the SCS/ES that modulated aerosol lifecycle. TC inflow arms of significant convection sometimes span from Sumatra to Luzon, resulting in very low particle concentrations (minimum condensation nuclei CN < 150 cm-3, non-sea salt PM2.5=1μg m-3). However, elevated carbon monoxide levels were occasionally observed suggesting passage of polluted air masses whose aerosol particles had been rained out. Conversely, two drier periods occurred with higher aerosol particle concentrations originating from Borneo and Southern Sumatra (CN > 3000 cm-3 and non-sea salt PM2.510-25 μg m-3). These

  14. "You Don't Want a Smart Alec": Selecting Examiners to Assess Doctoral Dissertations

    ERIC Educational Resources Information Center

    Kiley, Margaret

    2009-01-01

    The use of external examiners in the doctoral assessment process is seen as a quality assurance process in most higher education systems. This article suggests that the selection of examiners is a critical aspect of that process. Interview analysis highlights the professional/academic considerations involved in selecting suitable examiners, as…

  15. Christi Makes Sense of Sixth-Grade Mathematics.

    ERIC Educational Resources Information Center

    Ridlon, Candice L.

    2000-01-01

    Discusses experiences using a new mathematics curriculum with sixth grade students for nine weeks. Presents a student's discovery of her power in mathematics through this problem-centered curriculum. (ASK)

  16. 76 FR 18395 - Safety Zone; Naval Air Station Corpus Christi Air Show, Oso Bay, Corpus Christi, TX

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-04

    ... necessary to provide for the safety of other vessels and users of the waterway. Persons and vessels would be...: The owners or operators of vessels intending to transit the affected waterway during the time of...., specifications of materials, performance, design, or operation; test methods; sampling procedures; and...

  17. Madden-Julian Oscillation simulated in BCC climate models

    NASA Astrophysics Data System (ADS)

    Zhao, Chongbo; Ren, Hong-Li; Song, Lianchun; Wu, Jie

    2015-12-01

    This study evaluates the ability of four versions BCC (Beijing Climate Center or National Climate Center) models (BCC_AGCM2.1, BCC_AGCM2.2, BCC_CSM1.1 and BCC_CSM1.1m) in simulating the MJO phenomenon using the outputs of the AMIP (Atmospheric Model Intercomparison Project) and historical runs. In general, the models can simulate some major characteristics of the MJO, such as the intensity, the periodicity, the propagation, and the temporal/spatial evolution of the MJO signals in the tropics. There are still some biases between the models and the observation/reanalysis data, such as the overestimated total intraseasonal variability, but underestimated MJO intensity, shorter significant periodicity, and excessive westward propagation. The differences in the ability of simulating the MJO between AMIP and historical experiments are also significant. Compared to the AMIP runs, the total intraseasonal variability is reduced and more realistic, however the ratio between the MJO and its westward counterpart decreases in the historical runs. This unrealistic simulation of the zonal propagation might have been associated with the greater mean precipitation over the Pacific and corresponded to the exaggeration of the South Pacific Convergence Zone structure in precipitation mean state. In contrast to the T42 versions, the improvement of model resolution demonstrate more elaborate topography, but the enhanced westward propagation signals over the Arabia Sea followed. The underestimated (overestimated) MJO variability over eastern Indian Ocean (Pacific) was assumed to be associated with the mean state. Three sets of sensitive experiments using BCC_CSM1.1m turn out to support this argument.

  18. Observations of the temporal variability in aerosol properties and their relationships to meteorology in the summer monsoonal South China Sea/East Sea: the scale-dependent role of monsoonal flows, the Madden-Julian Oscillation, tropical cyclones, squall lines and cold pools

    NASA Astrophysics Data System (ADS)

    Reid, J. S.; Lagrosas, N. D.; Jonsson, H. H.; Reid, E. A.; Sessions, W. R.; Simpas, J. B.; Uy, S. N.; Boyd, T. J.; Atwood, S. A.; Blake, D. R.; Campbell, J. R.; Cliff, S. S.; Holben, B. N.; Holz, R. E.; Hyer, E. J.; Lynch, P.; Meinardi, S.; Posselt, D. J.; Richardson, K. A.; Salinas, S. V.; Smirnov, A.; Wang, Q.; Yu, L.; Zhang, J.

    2015-02-01

    In a joint NRL/Manila Observatory mission, as part of the Seven SouthEast Asian Studies program (7-SEAS), a 2-week, late September 2011 research cruise in the northern Palawan archipelago was undertaken to observe the nature of southwest monsoonal aerosol particles in the South China Sea/East Sea (SCS/ES) and Sulu Sea region. Previous analyses suggested this region as a receptor for biomass burning from Borneo and Sumatra for boundary layer air entering the monsoonal trough. Anthropogenic pollution and biofuel emissions are also ubiquitous, as is heavy shipping traffic. Here, we provide an overview of the regional environment during the cruise, a time series of key aerosol and meteorological parameters, and their interrelationships. Overall, this cruise provides a narrative of the processes that control regional aerosol loadings and their possible feedbacks with clouds and precipitation. While 2011 was a moderate El Niño-Southern Oscillation (ENSO) La Niña year, higher burning activity and lower precipitation was more typical of neutral conditions. The large-scale aerosol environment was modulated by the Madden-Julian Oscillation (MJO) and its associated tropical cyclone (TC) activity in a manner consistent with the conceptual analysis performed by Reid et al. (2012). Advancement of the MJO from phase 3 to 6 with accompanying cyclogenesis during the cruise period strengthened flow patterns in the SCS/ES that modulated aerosol life cycle. TC inflow arms of significant convection sometimes span from Sumatra to Luzon, resulting in very low particle concentrations (minimum condensation nuclei CN < 150 cm-3, non-sea-salt PM2.5 < 1 μg m-3). However, elevated carbon monoxide levels were occasionally observed suggesting passage of polluted air masses whose aerosol particles had been rained out. Conversely, two drier periods occurred with higher aerosol particle concentrations originating from Borneo and Southern Sumatra (CN > 3000 cm-3 and non-sea-salt PM2.5 10-25 μg m

  19. 76 FR 18391 - Safety Zone; Texas International Boat Show Power Boat Races; Corpus Christi Marina, Corpus...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-04

    ... zone will be implemented for the 15 minutes before each race or race heat. The same methods of... safety zone approximately 15 minutes following the conclusion of each race or race heat when the power... race heat. Vessels may transit through the safety zone with permission from the Captain of the...

  20. Delineation of marsh types from Corpus Christi Bay, Texas, to Perdido Bay, Alabama, in 2010

    USGS Publications Warehouse

    Enwright, Nicholas M.; Hartley, Stephen B.; Couvillion, Brady R.; Michael G. Brasher; Jenneke M. Visser; Michael K. Mitchell; Bart M. Ballard; Mark W. Parr; Barry C. Wilson

    2015-01-01

    This study incorporates about 9,800 ground reference locations collected via helicopter surveys in coastal wetland areas. Decision-tree analyses were used to classify emergent marsh vegetation types by using ground reference data from helicopter vegetation surveys and independent variables such as multitemporal satellite-based multispectral imagery from 2009 to 2011, bare-earth digital elevation models based on airborne light detection and ranging (lidar), alternative contemporary land cover classifications, and other spatially explicit variables. Image objects were created from 2010 National Agriculture Imagery Program color-infrared aerial photography. The final classification is a 10-meter raster dataset that was produced by using a majority filter to classify image objects according to the marsh vegetation type covering the majority of each image object. The classification is dated 2010 because the year is both the midpoint of the classified multitemporal satellite-based imagery (2009–11) and the date of the high-resolution airborne imagery that was used to develop image objects. The seamless classification produced through this work can be used to help develop and refine conservation efforts for priority natural resources.

  1. "Cisneros v. CCISD" the Desegregation of the Corpus Christi Independent School District

    ERIC Educational Resources Information Center

    Trevino, John Albert

    2010-01-01

    The purpose of this historical case study was to add to the literature an analysis of the landmark legal case of Jose Cisneros v. CCISD. The outcome of this case established Mexican Americans as an ethnic minority and set the legal precedent that the 1954 Brown v. Board of Education Topeka ruling could be extended to other minorities beyond…

  2. The Living and the Dead in Education: Commentary on Julian Williams

    ERIC Educational Resources Information Center

    Jones, Peter E.

    2011-01-01

    Jean Lave and Ray McDermott (2002) did a service with their powerful reading of Marx's 1844 essay on "Estranged Labour" (Marx, 1964). In reworking Marx's critique of "alienated labour" in terms of "alienated learning," they reminded everyone of Marx's own impassioned revolt against the inhumanity of the capitalist order and found a novel way of…

  3. Characteristics Associated with the Madden-Julian Oscillation at Manus Island

    SciTech Connect

    Deng, Liping; McFarlane, Sally A.; Flaherty, Julia E.

    2013-05-15

    Ground-based high temporal and vertical resolution datasets from 2002 to 2008 of observations at the Atmospheric Radiation Measurement (ARM) Tropical Western Pacific (TWP) site on Manus Island, Papua New Guinea are used to examine the evolution of clouds and rainfall associated with the MJO life cycle. A composite MJO event is developed based on the NOAA MJO Index 4 using 13 events. The analysis shows that the cloud evolution during the composited MJO life cycle depicts a two-phase structure consisting of a development phase and a mature phase. During the development phase, congestus is the most important cloud type; during the mature phase, deep convection is the dominant cloud type. Consistent with this two-phase structure, the heavy rainfall frequency also shows a two-peak structure during the MJO life cycle. Light rainfall does not show a clear relation to the MJO life cycle, but shows variability on shorter time scales. From the development phase to the mature phase, the MJO structure shifts from the Type I to Type II structure, showing a different phase relationship between convection and dynamic fields (or wave motion) in the development and mature phases. During the shift, mid-level clouds play an important role in moving moisture to the mid-troposphere and preparing the atmosphere for the following deep convection. The discharge-recharge theory explains some of observed features of the MJO evolution at the ARM TWP Manus Island site.

  4. Interaction of deep and shallow convection is key to Madden-Julian Oscillation simulation

    NASA Astrophysics Data System (ADS)

    Zhang, Guang J.; Song, Xiaoliang

    2009-05-01

    This study investigates the role of the interaction between deep and shallow convection in MJO simulation using the NCAR CAM3. Two simulations were performed, one using a revised Zhang-McFarlane convection scheme for deep convection and the Hack scheme for shallow convection, and the other disallowing shallow convection below 700 mb in the tropical belt. The two simulations produce dramatically different MJO characteristics. While the control simulation produces realistic MJOs, the simulation without shallow convection has very weak MJO signals in the Indian Ocean and western Pacific. Composite analysis finds that shallow convection serves to precondition the lower troposphere by moistening it ahead of deep convection. It also produces enhanced low-level mass convergence below 850 mb ahead of deep convection. This work, together with previous studies, suggests that a correct simulation of the interaction between deep and shallow convection is key to MJO simulation in global climate models.

  5. Application of terrestrial photogrammetry for the mass balance calculation on Montasio Occidentale Glacier (Julian Alps, Italy)

    NASA Astrophysics Data System (ADS)

    Piermattei, Livia; Carturan, Luca; Calligaro, Simone; Blasone, Giacomo; Guarnieri, Alberto; Tarolli, Paolo; Dalla Fontana, Giancarlo; Vettore, Antonio

    2014-05-01

    Digital elevation models (DEMs) of glaciated terrain are commonly used to measure changes in geometry and hence infer the mass balance of glaciers. Different tools and methods exist to obtain information about the 3D geometry of terrain. Recent improvements on the quality and performance of digital cameras for close-range photogrammetry, and the development of automatic digital photogrammetric processing makes the 'structure from motion' photogrammetric technique (SfM) competitive for high quality 3D models production, compared to efficient but also expensive and logistically-demanding survey technologies such as airborn and terrestrial laser scanner (TLS). The purpose of this work is to test the SfM approach, using a consumer-grade SLR camera and the low-cost computer vision-based software package Agisoft Photoscan (Agisoft LLC), to monitor the mass balance of Montasio Occidentale glacier, a 0.07km2, low-altitude, debris-covered glacier located in the Eastern Italian Alps. The quality of the 3D models produced by the SfM process has been assessed by comparison with digital terrain models obtained through TLS surveys carried out at the same dates. TLS technique has indeed proved to be very effective in determining the volume change of this glacier in the last years. Our results shows that the photogrammetric approach can produce point cloud densities comparable to those derived from TLS measurements. Furthermore, the horizontal and vertical accuracies are also of the same order of magnitude as for TLS (centimetric to decimetric). The effect of different landscape characteristics (e.g. distance from the camera or terrain gradient) and of different substrata (rock, debris, ice, snow and firn) was also evaluated in terms of SfM reconstruction's accuracy vs. TLS. Given the good results obtained on the Montasio Occidentale glacier, it can be concluded that the terrestrial photogrammetry, with the advantageous features of portability, ease of use and above all low costs, allows to obtain high-resolution DEMs which enable good mass balance estimations on glaciers with similar characteristics.

  6. Variability of Madden Julian Oscillations (MJO) observed over southern India using radiosonde observations

    NASA Astrophysics Data System (ADS)

    Leena, P. P.; Ratnam, M. Venkat; Krishna Murthy, B. V.; Bhaskara Rao, S. Vijaya

    2016-05-01

    In the present work, characteristics of 30-50 day oscillations (referred to as the MJO) in tropospheric and lower stratospheric wind and temperature have been studied using long-term high resolution radiosonde observations at a tropical station, Gadanki (13.5°N, 79.2°E) for the period 2006-2012. Wind and temperature perturbations showed clear features of the MJO with higher amplitudes between 10 and 18 km altitude. Interestingly, the MJO signal is confined vertically to different altitudes in different seasons. Variability in the perturbations of wind and temperature similar to that of outgoing long-wave radiation (OLR) with a few cases showing an out of phase relation. The amplitudes of these oscillations are larger in the winter and pre-monsoon seasons than in the monsoon season where the largest amplitudes are confined below the Tropical Easterly Jet (~16 km). There also exists a large inter-annual variability in the MJO. Spatio-temporal variability of OLR not only showed the features of the MJO but also northward and eastward propagation in the monsoons and winter seasons, respectively, in a few cases. It is found that convection leads the MJO in the zonal wind by 8-12 days in all the seasons except in winter. One intriguing result observed is the vitiation of the MJO pattern by the presence of strong wind shears during monsoon season. We expect this study would be helpful in representing the MJO features in the vertical in the general circulation models (GCMs) which is still a major challenge.

  7. Contribution of the maritime continent convection during the preconditioning stage of the Madden-Julian Oscillation

    NASA Astrophysics Data System (ADS)

    Kubota, H.; Yoneyama, K.; Nasuno, T.; Hamada, J.

    2013-12-01

    During the international field experiment 'Cooperative Indian Ocean experiment on intraseasonal variability in the Year 2011 (CINDY2011)', the preconditioning process of the MJO was observed. In this study, the contribution of the maritime continent convection was focused on the preconditioning process of the third MJO. During the preconditioning stage of the MJO, westward propagating disturbances were observed from Sumatera Island to the central Indian Ocean and moistened the atmosphere. Convections over the Sumatera Island were activated around December 15th when the moist air mass reached from South China Sea. The origin of the moist air mass was tropical cyclone which was formed in South China Sea in December 10th. The high moisture associated with tropical cyclone activated the convection over Sumatera Island, promoted westward propagating disturbances, and acted a favorable environment for the preconditioning of the MJO. This preconditioning stage of the MJO is simulated by Nonhydrostatic ICosahedral Atmospheric Model (NICAM) and investigated the moistening process.

  8. Archive of digital and digitized analog boomer seismic reflection data collected during USGS cruise 96CCT02 in Copano, Corpus Christi, and Nueces Bays and Corpus Christi Bayou, Texas, July 1996

    USGS Publications Warehouse

    Harrison, Arnell S.; Dadisman, Shawn V.; Kindinger, Jack G.; Morton, Robert A.; Blum, Mike D.; Wiese, Dana S.; Subiño, Janice A.

    2007-01-01

    In June of 1996, the U.S. Geological Survey conducted geophysical surveys from Nueces to Copano Bays, Texas. This report serves as an archive of unprocessed digital boomer seismic reflection data, trackline maps, navigation files, GIS information, cruise log, and formal FGDC metadata. Filtered and gained digital images of the seismic profiles and high resolution scanned TIFF images of the original paper printouts are also provided. The archived trace data are in standard Society of Exploration Geophysicists (SEG) SEG-Y format (Barry and others, 1975) and may be downloaded and processed with commercial or public domain software such as Seismic Unix (SU). Example SU processing scripts and USGS software for viewing the SEG-Y files (Zihlman, 1992) are also provided.

  9. Regular and Novel Metonymy: Can You Curl up with a Good Agatha Christie in Your Second Language?

    ERIC Educational Resources Information Center

    Slabakova, Roumyana; Cabrelli Amaro, Jennifer; Kyun Kang, Sang

    2016-01-01

    This article presents results of two off-line comprehension tasks investigating the acceptability of unconventional and conventional metonymy by native speakers of Korean and Spanish who speak English as a second language. We are interested in discovering whether learners differentiate between conventional and unconventional metonymy, and whether…

  10. 33 CFR 3.40-35 - Sector Corpus Christi Marine Inspection Zone and Captain of the Port Zone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the junction of the sea and the east bank of the Colorado River at latitude 28°35′44″ N, longitude 95°58′48″ W, proceeding north along the east bank of the Colorado River to Colorado County, TX; thence... boundaries of Colorado, Fayette, Bastrop, Travis, Burnet, Llano, Mason, Menard, Schletcher, Irion,...

  11. 33 CFR 3.40-35 - Sector Corpus Christi Marine Inspection Zone and Captain of the Port Zone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... the junction of the sea and the east bank of the Colorado River at latitude 28°35′44″ N, longitude 95°58′48″ W, proceeding north along the east bank of the Colorado River to Colorado County, TX; thence... boundaries of Colorado, Fayette, Bastrop, Travis, Burnet, Llano, Mason, Menard, Schletcher, Irion,...

  12. 33 CFR 3.40-35 - Sector Corpus Christi Marine Inspection Zone and Captain of the Port Zone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... the junction of the sea and the east bank of the Colorado River at latitude 28°35′44″ N, longitude 95°58′48″ W, proceeding north along the east bank of the Colorado River to Colorado County, TX; thence... boundaries of Colorado, Fayette, Bastrop, Travis, Burnet, Llano, Mason, Menard, Schletcher, Irion,...

  13. 78 FR 13015 - Foreign-Trade Zone 122-Corpus Christi, Tx; Application for Reorganization Under Alternative Site...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-26

    ... February 20, 2013. FTZ 122 was approved by the Board on September 5, 1985 (Board Order 310, 50 FR 38020, 9/19/1985) and expanded on December 6, 1991 (Board Order 545, 56 FR 65884, 12/19/1991), and on September 1, 1995 (Board Order 764, 60 FR 47149, 9/11/1995). The current zone includes the following...

  14. Convective Characteristics of the Madden-Julian Oscillation over the Central Indian Ocean Observed by Shipborne Radar during DYNAMO

    NASA Astrophysics Data System (ADS)

    Xu, W.; Rutledge, S. A.

    2013-12-01

    This study is motivated to quantify cloud population and convective properties throughout different MJO phases, and examine their relationships with the environment (e.g., moisture, SST, and CAPE). This study is based on C-band shipborne radar observations during the 2011-2012 international DYNAMO field campaign (collected on board the R/V Roger Revelle). In this study, we provide information about the MJO convection such as the cloud morphology (both height and size), convective intensity, rainfall contributions by different cloud type (including convective and stratiform), and lightning frequency. In addition, variability of all convective quantities as a function of MJO phase will be further related to environmental changes, e.g., sea surface temperature (SST), tropospheric humidity and CAPE. These high-resolution radar measurements collected on the R/V Revelle located ~600 km to the east of the Gan Island. Hence we can also examine the regional variability of convective population within the MJO initiation key area by comparing with studies based on the Gan Island radars deployed for DYNAMO. Preliminary results indicate close relations among changes of atmospheric moisture, SST, and the convective population. For example, the moistening of the lower troposphere from the suppressed stage (phase 5-7) to inactive pre-onset stage (phase 8-1) coincides with the growth of shallow or isolated convection. Similarly, significant mid-to-upper troposphere moistening occurs immediately after the onset of the deep convective phase (phase 2). The upper troposphere becomes the moistest during the phase 2 when number of deep convective cells, the population of MCSs and total precipitation reach their peak. At phase 3 (still active phase), though large MCSs are still prevailing, convection becomes slightly shallower and stratiform precipitation is dominating. These findings are generally consistent to the conceptual model of MJO initiation and those findings in the literature. The convective structures and relationships with the atmospheric and upper ocean conditions in different MJO phase will be analyzed in more depth.

  15. Simulated effects of projected pumping on the availability of freshwater in the Evangeline Aquifer in an area southwest of Corpus Christi, Texas

    USGS Publications Warehouse

    Groschen, G.E.

    1985-01-01

    This study is an investigation of the continued availability of freshwater in the Evangeline aquifer along the Texas Gulf Coast and the potential for degradation of the water quality by saline water intrusion. Recharge to the aquifer occurs by the infiltration of precipitation in the outcrop area and by cross-formational flow from deeper aquifers. The pre-development recharge rate is about 6 to 8 cu ft/sec. Discharge, under natural conditions, is upward into the Chicot aquifer and to the Nueces River or Gulf of Mexico. Intensive pumping by irrigators, industries, and municipalities over the last 80 yr has created a cone of depression as deep as 219 ft below sea level under the city of Kingsville in Kleberg County. The total rate of pumpage in 1982 was 29.6 cu ft/sec. A mathematical model of the flow and water quality in the Evangeline aquifer was developed using available data to simulate the historical effect of pumping on the potentiometric surface and water quality, and to simulate the effect of projected pumping on the potentiometric surface and water quality to the year 2020. The water quality in the aquifer is only marginally suitable for drinking water. The chloride concentration before development in the 1930 's and 1940's, ranged from 9 to 1,971 mg/L. The mean chloride concentration was 353 (standard deviation 262) mg/L. The potential sources of water quality degradation on a regional scale are: saline water intrusion from under the Gulf of Mexico; movement of poor quality water within outlying sections of the aquifer; and downward leakage from the overlying Chicot aquifer. Leakage from the Chicot is the most likely to cause serious regional water quality degradation. The simulations and the sensitivity tests of the aquifer properties, conditions, and assumptions indicate that vertical conductivity of the Chicot aquifer is the most sensitive and least well known part of the system. Two simulations of the projected pumping--a low estimate , as much as 46.2 cu ft/sec during 2011-20; and a high estimate, as much as 60.0 cu ft/sec during the same period--indicate that no further regional water quality deterioration is likely to occur. (Author 's abstract)

  16. 33 CFR 165.809 - Security Zones; Port of Port Lavaca-Point Comfort, Point Comfort, TX and Port of Corpus Christi...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) PORTS AND WATERWAYS SAFETY REGULATED NAVIGATION AREAS AND LIMITED ACCESS AREAS Specific Regulated Navigation Areas and Limited Access Areas Eighth Coast Guard District § 165.809 Security Zones; Port of Port.... The Captain of the Port may be contacted via VHF Channel 16 or via telephone at (361) 888-3162 to...

  17. Step 1: Learn About Diabetes | NIH MedlinePlus the Magazine

    MedlinePlus

    ... from prediabetes to type 2 diabetes in 2013. Photo By: Frazer Harrison In 1995, singer Patti LaBelle ... manages the disease with healthy foods and exercise. Photo By: Frazer Harrison When Alec Baldwin was diagnosed ...

  18. Book Review: The end of time: the next revolution in our understanding of the universe. Julian Barbour, Weidenfeld and Nicholson, London, 384 pp., 16.95, ISBN 0195145925

    NASA Astrophysics Data System (ADS)

    Ellis, G. F. R.

    In the early part of this century, physicists, led notably by Albert Einstein and the pioneers of quantum theory-in particular Neils Bohr, Werner Heisenberg, and Paul Dirac-discovered that the underlying nature of physical reality is stranger than anyone had ever imagined. A series of brilliant insights led to the realisation, on the one hand, of the relative nature of space and time measurements, and hence of our basic concepts of space and time (ultimately leading to the discovery of nuclear energy), and on the other hand, of the quantum nature of matter, with its associated quantum statistics and uncertainty of prediction (leading to transistors and lasers). Combining these views ultimately led to a realisation of the necessity of the existence of anti-matter, and of the dynamic nature of the vacuum. Further developments led to an understanding of the existence of symmetries characterising the various families of elementary particles, and of the unified nature of the fundamental interactions when described as gauge theories with forces mediated by exchange of gauge bosons. These properties have all been confirmed by carefully controlled experiments.

  19. Drug Prevention, Rehabilitation, Interdiction, and Law Enforcement (Corpus Christi, TX). Hearing before the Select Committee on Narcotics Abuse and Control. House of Representatives, Ninety-Eighth Congress, First Session (December 12 and 13, 1983).

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. House Select Committee on Narcotics Abuse and Control.

    This document provides transcripts of two consecutive days of Congressional hearings on narcotics abuse and control. Opening statements from Representatives Benjamin A. Gilman, Kent Hance, and Solomon P. Ortiz are presented. Testimony and prepared statements of 61 counselors and administrators in the field of substance abuse, public officials, law…

  20. 3. Historic American Buildings Survey L. D. Andrew, Photographer Dec. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Historic American Buildings Survey L. D. Andrew, Photographer Dec. 30, 1936 VIEW FROM CORNER OF WHITAKER AND ST JULIAN SHOWING NORTH FACADE - Gibbons Block, Congress, Saint Julian, Barnard, Whitaker Streets, Savannah, Chatham County, GA

  1. Students in Austin, Texas Learn About Space Exploration and Science

    NASA Video Gallery

    From NASA's International Space Station Mission Control Center, Christie Sauers, Orion Cockpit Working Group Deputy, participates in a Digital Learning Network (DLN) event with students at the Ann ...

  2. 33 CFR 165.801 - Annual fireworks displays and other events in the Eighth Coast Guard District requiring safety...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... marker 172.4 to 170.3.2 on the Ohio River. (See 33 CFR 100). Sector UpperMississippi River Date Sponsor... 3rd Louisville Bats Baseball Club/Louisville Bats Fireworks Louisville, KY Ohio River Mile 603.0-604.0... Hooks Baseball Team/Friday Night Fireworks Corpus Christi Ship Channel, Corpus Christi, TX All...

  3. Nature Study: A Science Curriculum for Three and Four-Year-Olds.

    ERIC Educational Resources Information Center

    McDonald, JoAnn Montes; McDonald, Robert B.

    This chapter is a part of a book that recounts the year's work at the Early Childhood Development Center (ECDC) at Texas A & M University-Corpus Christi. Rather than an "elitist" laboratory school for the children of university faculty, the dual-language ECDC is a collaboration between the Corpus Christi Independent School District and the…

  4. Developing Partnerships for Adult Literacy Training: College/Community Cooperation.

    ERIC Educational Resources Information Center

    Flores, Agnes L.; And Others

    The Corpus Christi Literacy Council (CCLC) is an independent, non-profit educational organization operating through joint partnership and grant activities with Del Mar College (DMC) and community and government organizations in the Corpus Christi (Texas) area. The major purposes of the council are to establish comprehensive reading programs for…

  5. Early Childhood Literacy: Programs & Strategies To Develop Cultural, Linguistic, Scientific and Healthcare Literacy for Very Young Children & their Families, 2001 Yearbook.

    ERIC Educational Resources Information Center

    Cassidy, Jack, Ed.; Garrett, Sherrye D., Ed.

    This yearbook recounts the work in 2001 at the Early Childhood Development Center (ECDC) at Texas A & M University-Corpus Christi. Rather than an "elitist" laboratory school for the children of university faculty, the ECDC is a collaboration between the Corpus Christi Independent School District and the university, with an enrollment…

  6. 77 FR 58368 - Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-20

    ... Energy Regulatory Commission Notice of Application Corpus Christi Liquefaction, LLC Docket No. CP12-507... 77002, filed with the Federal Energy Regulatory Commission (Commission) an application in Docket No... terminal. In the same application, Cheniere Corpus Christi Pipeline, L.P. (CCP) (together Corpus...

  7. America Reads Reading Recovery Right To Read = Quality Tutoring. A Pilot Program.

    ERIC Educational Resources Information Center

    Cassidy, Jack; Linton, Thomas

    This chapter is part of a book that recounts the year's work at the Early Childhood Development Center (ECDC) at Texas A & M University-Corpus Christi. Rather than an "elitist" laboratory school for the children of university faculty, the dual-language ECDC is a collaboration between the Corpus Christi Independent School District and the…

  8. A University Lab School for the 21st Century: The Early Childhood Development Center.

    ERIC Educational Resources Information Center

    Cassidy, Jack; Sanders, Jana

    This chapter is part of a book that recounts the year's work at the Early Childhood Development Center (ECDC) at Texas A & M University-Corpus Christi. Rather than an "elitist" laboratory school for the children of university faculty, the ECDC is a collaboration between the Corpus Christi Independent School District and the university with an…

  9. A School Healthcare Program for Low Income Families of Very Young Children.

    ERIC Educational Resources Information Center

    Joyce, Esperanza Villanueva

    This chapter is part of a book that recounts the year's work at the Early Childhood Development Center (ECDC) at Texas A & M University-Corpus Christi. Rather than an "elitist" laboratory school for the children of university faculty, the dual-language ECDC is a collaboration between the Corpus Christi Independent School District and the…

  10. A Bibliometric Analysis of the Academic Influences of and on Evaluation Theorists' Published Works

    ERIC Educational Resources Information Center

    Heberger, Anne E.; Christie, Christina A.; Alkin, Marvin C.

    2010-01-01

    As is the case with other fields, there is motivation for studying the impact that the body of evaluation theory literature has within and outside the field. The authors used journal articles written by theorists included on the evaluation theory tree by Alkin and Christie (2004; Christie & Alkin, 2008) and published in the Web of Science, an…