First Remote Sensing Observations Of Trifluoromethane (Hfc-23) In The Upper Troposphere And Lower Stratosphere,
2012
Old Dominion University
First Remote Sensing Observations Of Trifluoromethane (Hfc-23) In The Upper Troposphere And Lower Stratosphere, Jeremy J. Harrison, Christopher D. Boone, Alexander T. Brown, Nicholas D. C. Allen, Geoffrey C. Toon, Peter F. Bernath
Chemistry & Biochemistry Faculty Publications
This work reports the first remote sensing measurements of atmospheric HFC-23 (CHF3) using solar occultation measurements made by the Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS) and the Jet Propulsion Laboratory Mark IV (MkIV) balloon interferometer. A total of 8809 ACE occultations measured between 2004 and 2010 have been processed, along with 24 MkIV occultations measured between 1989 and 2007. ACE data (yearly averages over the 10-25 km altitude range) in the tropics/subtropics (40°S-40°N) reveal a trend of 4.0 ± 1.6% per year in the growth of HFC-23 for 2004-2009 (or 3.9 ± 1.2% per year for 2004-2010), …
Analysis Of Iasi Tropospheric O₃ Data Over The Arctic During Polarcat Campaigns In 2008,
2012
Old Dominion University
Analysis Of Iasi Tropospheric O₃ Data Over The Arctic During Polarcat Campaigns In 2008, M. Pommier, C. Clerbaux, K. S. Law, G. Ancellet, P. Bernath, P.-F. Coheur, J. Hadji-Lazaro, D. Hurtmans, P. Nédélec, J.-D. Paris, F. Ravetta, T. B. Ryerson, H. Schlager, A. J. Weinheimer
Chemistry & Biochemistry Faculty Publications
Ozone data retrieved in the Arctic region from infrared radiance spectra recorded by the Infrared Atmospheric Sounding Interferometer (IASI) on board the MetOp-A European satellite are presented. They are compared with in situ and lidar observations obtained during a series of aircraft measurement campaigns as part of the International Polar Year POLARCAT activities in spring and summer 2008. Different air masses were sampled during the campaigns including clean air, polluted plumes originating from anthropogenic sources, forest fire plumes from the three northern continents, and stratospheric-influenced air masses. The comparison between IASI O3 [0–8 km], [0–12 km] partial columns and …
Standardized Precipitation Index: User Guide,
2012
University of Nebraska - Lincoln
Standardized Precipitation Index: User Guide, Mark Svoboda, Michael Hayes, Deborah Wood
National Drought Mitigation Center: Faculty Publications
Over the years, there has been much discussion on what drought indices should be used in a particular climate and for what application. Many drought definitions and indices have been developed and attempts have been made to provide some guidance on this issue. With this in mind, the Interregional Workshop on Indices and Early Warning Systems for Drought was organized and held at the University of Nebraska-Lincoln, United States of America, from 8 to 11 December 2009. It was jointly sponsored by the School of Natural Resources (SNR) of the University of Nebraska, the United States National Drought Mitigation Center …
Implications Of Decade Time Scale Arctic Plant Community Change On Ecosystem Function,
2012
University of Texas at El Paso
Implications Of Decade Time Scale Arctic Plant Community Change On Ecosystem Function, Mark Jason Lara
Open Access Theses & Dissertations
Almost half the global soil organic carbon pool is found in northern high latitudes. The majority of this soil carbon is stored in a greenhouse inert state within permafrost. As pronounced warming of high northern latitudes ensues, there is a strong likelihood that this substantial soil organic carbon pool will be mobilized to the atmosphere where it is likely to positively enhance greenhouse warming. Modeling studies suggest this positive feedback could alter future climate states of the Arctic and the globe, and affect how humans may need to adapt to climate change. Accordingly, understanding the patterns and controls and the …
Recent Changes In The Growth And Nutrient Limitation Of Benthic And Pelagic Algae In Arctic Tundra Ponds,
2012
University of Texas at El Paso
Recent Changes In The Growth And Nutrient Limitation Of Benthic And Pelagic Algae In Arctic Tundra Ponds, Christina Hernandez
Open Access Theses & Dissertations
Arctic ponds are a dominant feature in Barrow, Alaska. Ponds may function as carbon sinks during the growing season from production of photosynthetic organisms like algae; however, little work has been done on this topic. Environmental changes have been occurring in the Arctic stemming from climate change and human perturbations. The focus of this study was to assess a historically studied region for changes in algal primary production that may have been produced due to increases in temperature over the past 40 years and increased human development. Additionally, this study aimed to determine nutrient limitation of algal production in the …
Analysis Of Aerosol Particle Size Distributions Observed During Aerose V Campaign,
2012
University of Texas at El Paso
Analysis Of Aerosol Particle Size Distributions Observed During Aerose V Campaign, Mariana Guereque
Open Access Theses & Dissertations
The African continent is the principal contributor of mineral aerosols into the atmosphere. It is also a significant source of carbonaceous aerosols resulting from rampant biomass burning activities. Both aerosol types have a profound impact on climate change and are an important factor in climate modeling, regional weather forecasting, as well as health-impact studies. Due to their importance, it is beneficial to characterize the transport and evolution of these aerosols from their origins in Africa, across the Atlantic Ocean and into the Americas. In-situ aerosol number distributions were collected during the 2009 Aerosols and Ocean Science Expeditions (AEROSE) V campaign, …
High-Order Central Finite-Volume Schemes For Atmospheric Modeling,
2012
University of Texas at El Paso
High-Order Central Finite-Volume Schemes For Atmospheric Modeling, Kiran Kumar Katta
Open Access Theses & Dissertations
Atmospheric numerical modeling has been going through drastic changes over the past decade, mainly to utilize the massive computing capability of the petascale systems. This obliges the modelers to develop grid systems and numerical algorithms that facilitate exceptional level of scalability on these systems. The numerical algorithms that can address these challenges should have the local properties such as the high on-processor operation count and minimum parallel communication i.e., high parallel efficiency. They should also satisfy the following properties such as inherent local and global conservation, high-order accuracy, geometric flexibility, non-oscillatory advection and positivity preservation properties. The goal of this …
Net Ecosystem Production (Nep) Of The Great Plains, United States,
2012
U.S. Geological Survey
Net Ecosystem Production (Nep) Of The Great Plains, United States, Daniel Howard, Tagir Gilmanov, Yingxin Gu, Bruce Wylie, Li Zhang
Natural Resource Management Faculty Publications
Gross primary production (GPP) and ecosystem respiration (Re) are the fundamental environmental characteristics that promote carbon exchanges with the atmosphere (Chapin and others, 2009), although other exchanges of carbon, such as direct oxidation (Lovett and others, 2006), can modify net ecosystem production (NEP). The accumulation of carbon in terrestrial ecosystems results in systems in which soil organic matter (SOM) carbon often exceeds biomass carbon (Post and Kwon, 2000). This SOM pool exists at a steady state between GPP and Re in ecosystems unless drivers change or the ecosystem endures environmental perturbations (for example, climatic). As indicated by Wilhelm and others …
Fall 2012,
2012
Nova Southeastern University
Synergistic Use Of Remote Sensing And Modeling For Tracing Dust Storms In The Mediterranean,
2012
Sharda University, India
Synergistic Use Of Remote Sensing And Modeling For Tracing Dust Storms In The Mediterranean, D. G. Kaskaoutis, Anup K. Prasad, P. G. Kosmopoulos, P. R. Sinha, S. K. Kharol, P. Gupta, Hesham El-Askary, Menas Kafatos
Mathematics, Physics, and Computer Science Faculty Articles and Research
This study focuses on the detection of the dust source region and monitoring of the transport of the dust plume from its primary outflow to final deposition. The application area is the Sahara desert and the eastern Mediterranean, where two dust events occurred during the period 4–6 February 2009, an unusual event for a winter period. The Aqua-MODIS and OMI observations clearly define the spatial distribution of the dust plumes, while the CALIPSO observations of total attenuated backscatter (TAB) at 532 nm, depolarization ratio (DR), and attenuated color ratio (1064/532 nm) on 5 February 2009 provide a clear view and …
Fog- And Cloud-Induced Aerosol Modification Observed By The Aerosol Robotic Network (Aeronet),
2012
Universities Space Research Association
Fog- And Cloud-Induced Aerosol Modification Observed By The Aerosol Robotic Network (Aeronet), T. F. Eck, B. N. Holben, J. S. Reid, D. M. Giles, M. A. Rivas, Ramesh P. Singh, S. N. Tripathi, C. J. Bruegge, S. Platnick, G. T. Arnold, N. A. Krotkov, S. A. Carn, A. Sinyuk, O. Dubovik, A. Arola, J. S. Schafer, P. Artaxo, A. Smirnov, H. Chen, P. Goloub
Mathematics, Physics, and Computer Science Faculty Articles and Research
Large fine mode-dominated aerosols (submicron radius) in size distributions retrieved from the Aerosol Robotic Network (AERONET) have been observed after fog or low-altitude cloud dissipation events. These column-integrated size distributions have been obtained at several sites in many regions of the world, typically after evaporation of low-altitude cloud such as stratocumulus or fog. Retrievals with cloud-processed aerosol are sometimes bimodal in the accumulation mode with the larger-size mode often similar to 0.4-0.5 mu m radius (volume distribution); the smaller mode, typically similar to 0.12 to similar to 0.20 mu m, may be interstitial aerosol that were not modified by incorporation …
Process-Evaluation Of Tropospheric Humidity Simulated By General Circulation Models Using Water Vapor Isotopic Observations: 2. Using Isotopic Diagnostics To Understand The Mid And Upper Tropospheric Moist Bias In The Tropics And Subtropics,
2012
Old Dominion University
Process-Evaluation Of Tropospheric Humidity Simulated By General Circulation Models Using Water Vapor Isotopic Observations: 2. Using Isotopic Diagnostics To Understand The Mid And Upper Tropospheric Moist Bias In The Tropics And Subtropics, Camille Risi, David Noone, John Worden, Christian Frankenberg, Gabriele Stiller, Michael Kiefer, Bernd Funke, Kaley Walker, Peter Bernath, Matthias Schneider, Sandrine Bony, Jeonghoon Lee, Derek Brown, Christophe Sturm
Chemistry & Biochemistry Faculty Publications
Evaluating the representation of processes controlling tropical and subtropical tropospheric relative humidity (RH) in atmospheric general circulation models (GCMs) is crucial to assess the credibility of predicted climate changes. GCMs have long exhibited a moist bias in the tropical and subtropical mid and upper troposphere, which could be due to the mis-representation of cloud processes or of the large-scale circulation, or to excessive diffusion during water vapor transport. The goal of this study is to use observations of the water vapor isotopic ratio to understand the cause of this bias. We compare the three-dimensional distribution of the water vapor isotopic …
Catastrophe And The Life Span Of Coral Reefs,
2012
Florida Institute of Technology
Catastrophe And The Life Span Of Coral Reefs, Richard B. Aronson, William F. Precht, Ian G. Macintyre, Lauren T. Toth
Ocean Engineering and Marine Sciences Faculty Publications
A strong earthquake in the western Caribbean in 2009 had a catastrophic impact on uncemented, unconsolidated coral reefs in the central sector of the shelf lagoon of the Belizean barrier reef. In a set of 21 reef sites that had been observed prior to the earthquake, the benthic assemblages of 10 were eradicated, and one was partially damaged, by avalanching of their slopes. Ecological dynamics that had played out over the previous 23 years, including the mass mortalities of two sequentially dominant coral species and a large increase in the cover of an encrusting sponge, were instantaneously rendered moot in …
Power Estimates Associated With Internal Tides From The Monterey Bay Area,
2012
Florida Institute of Technology
Power Estimates Associated With Internal Tides From The Monterey Bay Area, Steven M. Jachec
Ocean Engineering and Marine Sciences Faculty Publications
Numerical modeling has proven to be a useful method for simulating internal tides within the coastal ocean. Monterey Bay is a location that experiences energetic semidiurnal internal tides, and they are pronounced within Monterey Submarine Canyon. Numerical simulations and field measurements indicate that the baroclinic energy fluxes there are spatially variable, leading to locations of positive and negative baroclinic energy flux divergences. Results derived from a SUNTANS (Stanford Unstructured Nonhydrostatic Terrain-following Adaptive Navier-Stokes Simulator) model simulation show that Monterey Submarine Canyon’s baroclinic power is net dissipative (–8.3 MW). However, sources and sinks exist throughout the canyon, and they permeate the …
Gene Transcription In Sea Otters (Enhydra Lutris); Development
Of A Diagnostic Tool For Sea Otter And Ecosystem Health,
2012
Western Ecological Research Center
Gene Transcription In Sea Otters (Enhydra Lutris); Development Of A Diagnostic Tool For Sea Otter And Ecosystem Health, Lizabeth Bowen, A. Keith Miles, Michael Murray, Martin Haulena, Judy Tuttle, William Van Bonn, Lance Adams, James L. Bodkin, Brenda Ballachey, James A. Estes, M. Tim Tinker, Robin Keister, Jeffrey L. Stott
United States Geological Survey: Staff Publications
Gene transcription analysis for diagnosing or monitoring wildlife health requires the ability to distinguish pathophysiological change from natural variation. Herein, we describe methodology for the development of quantitative real-time polymerase chain reaction (qPCR) assays to measure differential transcript levels of multiple immune function genes in the sea otter (Enhydra lutris); sea otter-specific qPCR primer sequences for the genes of interest are defined. We establish a ‘reference’ range of transcripts for each gene in a group of clinically healthy captive and free-ranging sea otters. The 10 genes of interest represent multiple physiological systems that play a role in immuno-modulation, …
Do Bioclimate Variables Improve Performance Of Climate Envelope Models?,
2012
University of Florida
Do Bioclimate Variables Improve Performance Of Climate Envelope Models?, James I. Watling, Stephanie S. Romanach, David N. Bucklin, Carolina Speroterra, Laura A. Brandt, Leonard G. Pearlstine, Frank J. Mazzotti
United States Geological Survey: Staff Publications
Climate envelope models are widely used to forecast potential effects of climate change on species distributions. A key issue in climate envelope modeling is the selection of predictor variables that most directly influence species. To determine whether model performance and spatial predictions were related to the selection of predictor variables, we compared models using bioclimate variables with models constructed from monthly climate data for twelve terrestrial vertebrate species in the southeastern USA using two different algorithms (random forests or generalized linear models), and two model selection techniques (using uncorrelated predictors or a subset of user-defined biologically relevant predictor variables). There …
Global Air Temperature
Variability Independent Of
Sea-Surface Temperature
Influences,
2012
University of Arizona
Global Air Temperature Variability Independent Of Sea-Surface Temperature Influences, Andrew C. Comrie, Gregory J. Mccabe
United States Geological Survey: Staff Publications
Mean global surface air temperature (SAT) and sea surface temperature (SST) display substantial variability on timescales ranging from annual to multi-decadal. We review the key recent literature on connections between global SAT and SST variability. Although individual ocean influences on SAT have been recognized, the combined contributions of worldwide SST variability on the global SAT signal have not been clearly identified in observed data.Weanalyze these relations using principal components of detrended SST, and find that removing the underlying combined annual, decadal, and multi-decadal SST variability from the SAT time series reveals a nearly monotonic global warming trend in SAT since …
Gonadal Abnormalities In Frogs (Lithobates Spp.) Collected From Managed Wetlands
In An Agricultural Region Of Nebraska, Usa,
2012
U.S. Geological Survey
Gonadal Abnormalities In Frogs (Lithobates Spp.) Collected From Managed Wetlands In An Agricultural Region Of Nebraska, Usa, Diana M. Papoulias, Matt S. Schwarz, Lourdes Mena
United States Geological Survey: Staff Publications
Nebraska’s Rainwater Basin (RWB) provides important wetland habitat for North American migratory birds. Concern exists that pesticide and nutrient runoff from surrounding row-crops enters wetlands degrading water quality and adversely affecting birds and wildlife. Frogs may be especially vulnerable. Plains leopard (Lithobates blairi) metamorphs from RWB wetlands with varying concentrations of pesticides were evaluated for a suite of biomarkers of exposure to endocrine active chemicals. Froglets had ovarian dysgenesis, high rates of testicular oocytes, and female-biased sex ratios however, there was no clear statistical association between pesticide concentrations and biomarkers. Data interpretation was hindered because timing and duration …
History And Evaluation Of National-Scale Geochemical Data Sets For The United
States,
2012
U.S. Geological Survey, Denver Federal Center
History And Evaluation Of National-Scale Geochemical Data Sets For The United States, David B. Smith, Steven M. Smith, John D. Horton
United States Geological Survey: Staff Publications
Six national-scale, or near national-scale, geochemical data sets for soils or stream sediments exist for the United States. The earliest of these, here termed the ‘Shacklette’ data set, was generated by a U.S. Geological Survey (USGS) project conducted from 1961 to 1975. This project used soil collected from a depth of about 20 cm as the sampling medium at 1323 sites throughout the conterminous U.S. The National Uranium Resource Evaluation Hydrogeochemical and Stream Sediment Reconnaissance (NUREHSSR) Program of the U.S. Department of Energy was conducted from 1975 to 1984 and collected either stream sediments, lake sediments, or soils at more …
Remote Sensing Of Evapotranspiration For Operational Drought
Monitoring Using Principles Of Water And Energy Balance,
2012
U.S. Geological Survey
Remote Sensing Of Evapotranspiration For Operational Drought Monitoring Using Principles Of Water And Energy Balance, Gabriel B. Senay, Stefanie Bohms, James P. Verdin
United States Geological Survey: Staff Publications
Evapotranspiration (ET) is an important component of the hydrologic budget because it reflects the exchange of mass and energy between the soil–water–vegetation system and the atmosphere. Prevailing weather conditions influence potential or reference ET through variables such as radiation, temperature, wind, and relativity humidity. In addition to these weather variables, actual ET (ETa) is also affected by land cover type and condition, as well as soil moisture. The dependence of ETa on land cover and soil moisture, and its direct relationship with carbon dioxide assimilation in plants, makes it an important variable for monitoring drought, crop yield, …
