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Articles 601 - 630 of 773

Full-Text Articles in Other Oceanography and Atmospheric Sciences and Meteorology

Early Miocene Antarctic Glacial History: New Insights From Heavy Mineral Analysis From Andrill And–2a Drill Core Sediments, Francesco Iacoviello, Giovanna Giorgetti, Isabella Turbanti Memmi, Sandra Passchier Apr 2015

Early Miocene Antarctic Glacial History: New Insights From Heavy Mineral Analysis From Andrill And–2a Drill Core Sediments, Francesco Iacoviello, Giovanna Giorgetti, Isabella Turbanti Memmi, Sandra Passchier

ANDRILL Research and Publications

The present study deals with heavy mineral analysis of late Early Miocene marine sediments recovered in the McMurdo Sound region (Ross Sea, Antarctica) during the ANDRILL— SMS Project in 2007. The main objective is to investigate how heavy mineral assemblages reflect different source rocks and hence different provenance areas. These data contribute to a better understanding of East Antarctica ice dynamics in the Ross Sea sector during the Early Miocene (17.6–20.2 Ma), a time of long-term global warming and sea level rise. The AND-2A drill core recovered several stratigraphic intervals that span from Early Miocene to Pleistocene and it collected …


Sfa Weather Station-March 2015, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University Mar 2015

Sfa Weather Station-March 2015, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University

Weather Station Data

No abstract provided.


Sfa Weather Station-February 2015, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University Feb 2015

Sfa Weather Station-February 2015, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University

Weather Station Data

No abstract provided.


Multi-Scale Evaluation Of Light Use Efficiency In Modis Gross Primary Productivity For Croplands In The Midwestern United States, Qinchuan Xin, Mark Broich, Andrew E. Suyker, Le Yu, Peng Gong Jan 2015

Multi-Scale Evaluation Of Light Use Efficiency In Modis Gross Primary Productivity For Croplands In The Midwestern United States, Qinchuan Xin, Mark Broich, Andrew E. Suyker, Le Yu, Peng Gong

School of Natural Resources: Faculty Publications

Satellite remote sensing provides continuous observations of land surfaces, thereby offering opportunities for large-scale monitoring of terrestrial productivity. Production Efficiency Models (PEMs) have been widely used in satellite-based studies to simulate carbon exchanges between the atmosphere and ecosystems. However, model parameterization of the maximum light use efficiency (ε*GPP) varies considerably for croplands in agricultural studies at different scales. In this study, we evaluate cropland ε*GPP in the MODIS Gross Primary Productivity (GPP) model (MOD17) using in situ measurements and inventory datasets across the Midwestern US. The site-scale calibration using 28 site-years tower measurements derives ε*GPP values …


Dimethylsulfide Gas Transfer Coefficients From Algal Blooms In The Southern Ocean, T. G. Bell, Warren J. De Bruyn, Christa A. Marandino, S. D. Miller, C. S. Law, Eric S. Saltzman Jan 2015

Dimethylsulfide Gas Transfer Coefficients From Algal Blooms In The Southern Ocean, T. G. Bell, Warren J. De Bruyn, Christa A. Marandino, S. D. Miller, C. S. Law, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Air-sea dimethylsulfide (DMS) fluxes and bulk air-sea gradients were measured over the Southern Ocean in February-March 2012 during the Surface Ocean Aerosol Production (SOAP) study. The cruise encountered three distinct phytoplankton bloom regions, consisting of two blooms with moderate DMS levels, and a high biomass, dinoflagellate-dominated bloom with high seawater DMS levels (> 15 nM). Gas transfer coefficients were considerably scattered at wind speeds above 5 m s(-1). Bin averaging the data resulted in a linear relationship between wind speed and mean gas transfer velocity consistent with that previously observed. However, the wind-speed-binned gas transfer data distribution at all wind …


On Underestimation Of Global Vulnerability To Tree Mortality And Forest Die-Off From Hotter Drought In The Anthropocene, Craig D. Allen, David D. Breshears, Nate G. Mcdowell Jan 2015

On Underestimation Of Global Vulnerability To Tree Mortality And Forest Die-Off From Hotter Drought In The Anthropocene, Craig D. Allen, David D. Breshears, Nate G. Mcdowell

United States Geological Survey: Staff Publications

Patterns, mechanisms, projections, and consequences of tree mortality and associated broadscale forest die-off due to drought accompanied by warmer temperatures—‘‘hotter drought’’, an emerging characteristic of the Anthropocene—are the focus of rapidly expanding literature. Despite recent observational, experimental, and modeling studies suggesting increased vulnerability of trees to hotter drought and associated pests and pathogens, substantial debate remains among research, management and policy-making communities regarding future tree mortality risks. We summarize key mortalityrelevant findings, differentiating between those implying lesser versus greater levels of vulnerability. Evidence suggesting lesser vulnerability includes forest benefits of elevated [CO2] and increased water-use efficiency; observed and modeled increases …


The Simulation & Evaluation Of Surge Hazard Using A Response Surface Method In The New York Bight, Michael H. Bredesen Jan 2015

The Simulation & Evaluation Of Surge Hazard Using A Response Surface Method In The New York Bight, Michael H. Bredesen

UNF Graduate Theses and Dissertations

Atmospheric features, such as tropical cyclones, act as a driving mechanism for many of the major hazards affecting coastal areas around the world. Accurate and efficient quantification of tropical cyclone surge hazard is essential to the development of resilient coastal communities, particularly given continued sea level trend concerns. Recent major tropical cyclones that have impacted the northeastern portion of the United States have resulted in devastating flooding in New York City, the most densely populated city in the US. As a part of national effort to re-evaluate coastal inundation hazards, the Federal Emergency Management Agency used the Joint Probability Method …


Comparison Of Isotope-Based Biomass Pathways With Groundfish Community Structure In The Eastern Gulf Of Mexico, Sheri Ann Huelster Jan 2015

Comparison Of Isotope-Based Biomass Pathways With Groundfish Community Structure In The Eastern Gulf Of Mexico, Sheri Ann Huelster

USF Tampa Graduate Theses and Dissertations

This study compared traditional community analysis with stable-isotope trophic analysis to define process-based trophic elements of community structure in the eastern Gulf of Mexico, and developed a predictive capability regarding changes to fish community structure that would be expected from increasing eutrophication. Specifically, it used an existing trawl survey program (SEAMAP) to compare invertebrate herbivore (sponge and sea urchin) isotopes with groundfish isotopes, and then compared the resulting spatial patterns with spatial variation in community structure, as identified by cluster analysis. The comparison was applied to seven NMFS survey zones that extended offshore from the Caloosahatchee River, FL northwest to …


The Non-Lethal Effects Of Climate Change On The Territoriality Of Lottia Gigantea, Tracey Gunanto, Christina Chavez, Jessica Martinez, William G. Wright Dec 2014

The Non-Lethal Effects Of Climate Change On The Territoriality Of Lottia Gigantea, Tracey Gunanto, Christina Chavez, Jessica Martinez, William G. Wright

Student Scholar Symposium Abstracts and Posters

The intertidal zone has been described as ground zero for global warming. Here, the owl limpet, Lottia gigantea, adapted to the cool ocean temperatures, must withstand a few hours of baking sun during day-time low tides. This hardship is predicted to increase in frequency and severity in the future as the globe warms. Our research hypothesized that heat events compromise territorial behavior of L. gigantea. All observations and experiments were performed at Inspiration Point near Newport Beach, California. We measured the natural radiant temperature of tagged limpets during day-time low tides using a field-calibrated infrared “thermogun”. We also …


Long Term Ground Based Precipitation Data Analysis: Spatial And Temporal Variability, Luciano Rodriguez, Cyril S. Rakovski, Hesham El-Askary, Mohamed Allali Dec 2014

Long Term Ground Based Precipitation Data Analysis: Spatial And Temporal Variability, Luciano Rodriguez, Cyril S. Rakovski, Hesham El-Askary, Mohamed Allali

Student Scholar Symposium Abstracts and Posters

California is an area of diverse topography and has what many scientists call a Mediterranean climate. Various precipitation patterns exist due to El Niño Southern Oscillation (ENSO) which can cause abnormal precipitation or droughts. As temperature increases mainly due to the increase of CO2 in the atmosphere, it is rapidly changing the climate of not only California but the world. An increase in temperature is leading to droughts in certain areas as other areas are experiencing heavy rainfall/flooding. Droughts in return are providing a foundation for fires harming the ecosystem and nearby population. Various natural hazards can be induced due …


Sfa Weather Station-December 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University Dec 2014

Sfa Weather Station-December 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University

Weather Station Data

No abstract provided.


Sfa Weather Station-November 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University Nov 2014

Sfa Weather Station-November 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University

Weather Station Data

No abstract provided.


Sfa Weather Station-October 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University Oct 2014

Sfa Weather Station-October 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University

Weather Station Data

No abstract provided.


Sfa Weather Station-September 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University Sep 2014

Sfa Weather Station-September 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University

Weather Station Data

No abstract provided.


Climate Change And Its Implications For The Insurance Industry, Adam Liska, Eric Holley Sep 2014

Climate Change And Its Implications For The Insurance Industry, Adam Liska, Eric Holley

Adam Liska Papers

Climate change will lead to a probable increase in the occurrence of weather-related disaster events. These events could lead to declining revenue in the insurance industry, the world’s largest economic sector, with revenue of $4.6 trillion per year, or 7% of the global economy (Mills, 2012). Climatic events have accounted for 72% of global insurance claims and insured losses from 1980 to 2012, totaling $0.97 trillion (Munich Re, 2013). Estimated losses are ~0.5% of global Gross Domestic Product (GDP) and losses are increasing at ~6% a year in real terms (Lomborg, 2010). The United Nations Framework Convention on Climate Change …


Sfa Weather Station-August 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University Aug 2014

Sfa Weather Station-August 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University

Weather Station Data

No abstract provided.


Sfa Weather Station-July 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University Jul 2014

Sfa Weather Station-July 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University

Weather Station Data

No abstract provided.


Aerosol Association With Severe Weather In The Great Plains, Gabriel A. Lojero Jul 2014

Aerosol Association With Severe Weather In The Great Plains, Gabriel A. Lojero

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Aerosols particles may serve as cloud condensation nuclei (CCN) and therefore play an important role in modulating cloud microphysics, to the point where convective storm intensity may be altered. The purpose of this study is to determine the impacts of biomass burning aerosols on convective storms over the Great Plains, especially the southern Great Plains, and to show synoptic regimes characterizing differing aerosol concentrations. A new technique to identify days with a high concentration of biomass burning aerosols was developed by using organic carbon, potassium, zinc, and bromine as the predominant tracers. An eleven-year climatology (2002-2012) for the biomass burning …


Sfa Weather Station-June 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F Austin State University Jun 2014

Sfa Weather Station-June 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F Austin State University

Weather Station Data

No abstract provided.


Marine Viral Diversity And Spatiotemporal Variability, Dawn Goldsmith May 2014

Marine Viral Diversity And Spatiotemporal Variability, Dawn Goldsmith

USF Tampa Graduate Theses and Dissertations

Marine viruses are the most numerous biological entities in the ocean, with an estimated abundance of 4 x 1030. They merit study not only because of their sheer abundance, but also because of the role they play in the Earth's biogeochemical cycles. Viral lysis of bacteria redirects the flow of nutrients among marine microbes, which ultimately affects the efficiency of the biological pump. Viral diversity is important because most viruses are host-specific. In preying on a certain type of bacteria, viruses affect the diversity and structure of the bacterial community, leading to changes in carbon and nutrient flows. …


Sfa Weather Station-May 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University May 2014

Sfa Weather Station-May 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University

Weather Station Data

No abstract provided.


Sfa Weather Station-May 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University May 2014

Sfa Weather Station-May 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University

Weather Station Data

No abstract provided.


Spatial And Temporal Extent Of A Subsurface Hydrocarbon Intrusion Following The Deepwater Horizon Blowout, Kathleen Watson May 2014

Spatial And Temporal Extent Of A Subsurface Hydrocarbon Intrusion Following The Deepwater Horizon Blowout, Kathleen Watson

USF Tampa Graduate Theses and Dissertations

The Deepwater Horizon (DWH) oil spill in the Gulf of Mexico (GoM) released an estimated 4.9 million barrels of oil between April 20, 2010 and July 15, 2010. An estimated 36% of the oil formed a neutrally buoyant intrusion, containing both dissolved compounds and oil microdroplets, between 1000 and 1300 m depth. This study used geographic information systems software, and data from water samples that were collected as part of the National Resource Damage Assessment (NRDA), to determine that an area of at least 1,600 km2 was exposed to DWH oil. Toxic BTEX (benzene, toluene, ethylbenzene, and …


Improving Spectrophotometric Carbon System Measurements, Mark Patsavas Apr 2014

Improving Spectrophotometric Carbon System Measurements, Mark Patsavas

USF Tampa Graduate Theses and Dissertations

This work provides improved procedures for spectrophotometric carbon system measurements. Indicator dyes used for routine spectrophotometric pH measurements in seawater suffer from impurity issues, which introduce vendor-specific systematic errors in pH determinations. The magnitude of these errors for several vendors was investigated for meta Cresol Purple (mCP) and Cresol Red (CR). Flash chromatography procedures were developed to obtain purified mCP and CR on a bulk scale in order to supply the oceanographic research community with the indicators. Easy access to the purified indicators ensures global intercomparability of spectrophotometric pH determinations.

Internal consistency of marine inorganic carbon system measurements was studied …


Sfa Weather Station-April 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University Apr 2014

Sfa Weather Station-April 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University

Weather Station Data

No abstract provided.


Influence Of Diet On Element Incorporation In The Shells Of Two Bivalve Molluscs: Argopecten Irradians Concentricus And Mercenaria Mercenaria, William Noland Elsaesser Mar 2014

Influence Of Diet On Element Incorporation In The Shells Of Two Bivalve Molluscs: Argopecten Irradians Concentricus And Mercenaria Mercenaria, William Noland Elsaesser

USF Tampa Graduate Theses and Dissertations

Recently, biogenic carbonates have received much attention as potential proxies of environmental change; however, a major pathway of elemental incorporation is often overlooked when making interpretations or designing experiments. This research experimentally examines the influence of diet on elemental composition in juvenile shells of the bay scallop, Argopecten irradians concentricus, and the northern quahog, Mercenaria mercenaria.

Exploratory trials were conducted using Argopecten irradians concentricus juveniles fed different algal diets: Isochrysis, Chaetoceros, Pavlova, Tetraselmis, or a mix of all four in a 2:1:2:2 ratio. No differences between the left and right valves were revealed, thus, subsequent analysis of the dietary influence …


Epibenthic Mobile Invertebrates Along The Florida Reef Tract: Diversity And Community Structure, Kristin Netchy Mar 2014

Epibenthic Mobile Invertebrates Along The Florida Reef Tract: Diversity And Community Structure, Kristin Netchy

USF Tampa Graduate Theses and Dissertations

Benthic mobile invertebrates are important components of coral-reef diversity and community structure, though, in most cases, their ecological contributions are poorly known. Baseline information on their diversity, prevalence, assemblages, and ecological roles is needed to aid in the conservation of coral-reef habitats. The objectives of this study are to 1) describe diversity and assemblages of epibenthic, mobile invertebrates in shallow water coral-reef communities in Florida, 2) evaluate their ecological roles by reviewing published literature on diet, and 3) measure the degree of linear dependence between mobile invertebrates and scleractinian corals. Underwater surveys were conducted in the summer of 2013 at …


Sfa Weather Station-March 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University Mar 2014

Sfa Weather Station-March 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University

Weather Station Data

No abstract provided.


Sfa Weather Station-February 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University Feb 2014

Sfa Weather Station-February 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University

Weather Station Data

No abstract provided.


Data-Driven Diagnostics Of Terrestrial Carbon Dynamics Over North America, Jingfeng Xiao, Scott V. Ollinger, Steve Frolking, George Hurtt, David Y. Hollinger, Kenneth J. Davis, Yude Pan, Xiaoyang Zhang, Feng Deng, Jiquan Chen, Dennis D. Baldocchi, Beverly E. Law, M. Altaf Arain, Ankur R. Desai, Andrew D. Richardson, Ge Sun, Brian Amiro, Hank Margolis, Lianhong Gu, Russell L. Scott, Peter D. Blanken, Andrew E. Suyker Jan 2014

Data-Driven Diagnostics Of Terrestrial Carbon Dynamics Over North America, Jingfeng Xiao, Scott V. Ollinger, Steve Frolking, George Hurtt, David Y. Hollinger, Kenneth J. Davis, Yude Pan, Xiaoyang Zhang, Feng Deng, Jiquan Chen, Dennis D. Baldocchi, Beverly E. Law, M. Altaf Arain, Ankur R. Desai, Andrew D. Richardson, Ge Sun, Brian Amiro, Hank Margolis, Lianhong Gu, Russell L. Scott, Peter D. Blanken, Andrew E. Suyker

School of Natural Resources: Faculty Publications

The exchange of carbon dioxide is a key measure of ecosystem metabolism and a critical intersection between the terrestrial biosphere and the Earth’s climate. Despite the general agreement that the terrestrial ecosystems in North America provide a sizeable carbon sink, the size and distribution of the sink remain uncertain. We use a data-driven approach to upscale eddy covariance flux observations from towers to the continental scale by integrating flux observations, meteorology, stand age,aboveground biomass, and a proxy for canopy nitrogen concentrations from AmeriFlux and Fluxnet-Canada Research Network as well as a variety of satellite data streams from the MODIS sensors. …