Open Access. Powered by Scholars. Published by Universities.®

Earth Sciences

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 931 - 960 of 3306

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Developing Multispectral Imaging Techniques To Determine Canopy Coverage And Carbon Storage Of Seagrasses In The Gulf Of Mexico, Ivy Michelle Hinson Aug 2019

Developing Multispectral Imaging Techniques To Determine Canopy Coverage And Carbon Storage Of Seagrasses In The Gulf Of Mexico, Ivy Michelle Hinson

Theses and Dissertations

Although seagrass beds provide global ecosystem services, coverage is in rapid decline, with the capacity of seagrasses to sequester carbon of special concern. Current seagrass monitoring methods are labor intensive and may not offer a complete picture of coverage. Remote sensing offers the ability to oversee landscapes but water in coastal environments presents challenges, as the commonly used near-infrared wavelength dissipates in water.

This project aimed to provide reliable methodology to assess seagrass coverage using multispectral imagery taken from an unmanned aerial vehicle and to provide evidence for the link between seagrass coverage and stored belowground carbon for common seagrasses …


Changes In Mammalian Abundance Through The Eocene–Oligocene Climate Transition In The White River Group Of Nebraska, Usa, Robert Gillham Jul 2019

Changes In Mammalian Abundance Through The Eocene–Oligocene Climate Transition In The White River Group Of Nebraska, Usa, Robert Gillham

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

Marine records show major cooling during the Eocene-Oligocene Climate Transition (EOCT). Most proxy studies in the White River Group suggest drying across the EOCT, and some suggest cooling. The lower resolution continental record has hindered a direct correlation of the marine climate record to Nebraska. I explore various correlation schemes and what they imply for faunal changes. This study compiles and analyzes data from 4,875 specimens in the University of Nebraska State Museum (UNSM) collection to test the hypothesis that climate change across the Eocene-Oligocene (E-O) boundary caused significant abundance changes in mammals. A series of binning schemes was created. …


Management Regime And Habitat Response Influence Abundance Of Regal Fritillary (Speyeria Idalia) In Tallgrass Prairie, K. Mccullough, G. Albanese, D.A. Haukos, A.M. Ricketts, S. Stratton Jul 2019

Management Regime And Habitat Response Influence Abundance Of Regal Fritillary (Speyeria Idalia) In Tallgrass Prairie, K. Mccullough, G. Albanese, D.A. Haukos, A.M. Ricketts, S. Stratton

United States Geological Survey: Staff Publications

The >2,570,000-ha Flint Hills ecoregion of Kansas, USA, harbors the largest remaining contiguous tract of tallgrass prairie in North America, a unique system, as the remainder of North America’s tallgrass prairie has succumbed to development and conversion. Consequently, the loss and degradation of tallgrass prairie has reduced populations of many North American prairie-obligate species including the regal fritillary (Speyeria idalia) butterfly. Population abundance and occupied range of regal fritillary have declined >99%, restricting many populations to isolated, remnant patches of tallgrass prairie. Such extensive decline has resulted in consideration of the regal fritillary for protection under the Endangered Species Act. …


Perchlorate Behavior In The Context Of Black Carbon And Metal Cogeneration Following Fireworks Emission At Oak Lake, Lincoln, Nebraska, Usa, Manish Kumar, Daniel D. Snow, Yusong Li, Patrick Shea Jul 2019

Perchlorate Behavior In The Context Of Black Carbon And Metal Cogeneration Following Fireworks Emission At Oak Lake, Lincoln, Nebraska, Usa, Manish Kumar, Daniel D. Snow, Yusong Li, Patrick Shea

Nebraska Water Center: Faculty Publications

The imprints of fireworks displays on the adjacent water body were investigated from the perspective of cogeneration of black carbon, metals and perchlorate (ClO4–). In particular, the mixing and dissipation of ClO4– were studied at Oak Lake, Lincoln, Nebraska, following fireworks displays in 2015 and 2016. Following the display, ClO4– concentration in the water increased up to 4.3 μg/L and 4.0 μg/L in 2015 and 2016, respectively. A first-order model generally provided a good fit to the measured perchlorate concentrations from which the rate of dissipation was estimated as 0.07 d–1 in …


An Estimation Of Lower Tropospheric Mixing Derived From Inverse Modeling Of Boundary Layer Water Vapor Isotopologues On Graciosa Island, Azores, Jacquelyn M. Delp Jul 2019

An Estimation Of Lower Tropospheric Mixing Derived From Inverse Modeling Of Boundary Layer Water Vapor Isotopologues On Graciosa Island, Azores, Jacquelyn M. Delp

Earth and Planetary Sciences ETDs

Recent studies have shown water vapor isotopologues to be sensitive tracers of mixing processes that govern low-cloud feedback in climate models. In this study, we develop an inverse model (MBL Mix inverse model) that uses one year of isotope and humidity observations from Graciosa Island, Azores to estimate mixing for four seasons. We show the dry end-member of the model, the lower free troposphere (LFT), can be represented using Rayleigh fractionation. Isotope observations from Graciosa Island are compared to other field locations to discuss controls on isotopic variability other than mixing. Output from the MBL Mix inverse model shows the …


Drought Analyses Of The Horn´E PoˇZitavie Region (Slovakia) In The Period 1966–2013, Jaroslav Vido, Paulina Nalevankova, Jan Valach, Zbysek Sustek, Tsegaye Tadesse Jul 2019

Drought Analyses Of The Horn´E PoˇZitavie Region (Slovakia) In The Period 1966–2013, Jaroslav Vido, Paulina Nalevankova, Jan Valach, Zbysek Sustek, Tsegaye Tadesse

National Drought Mitigation Center: Faculty Publications

+is study focuses on the characterization of historical drought occurrences in the Horn´e Poˇzitavie region of Slovakia over the period 1966–2013 using Standardized Precipitation-Evapotranspiration Index (SPEI). Trend analyses were evaluated by the Mann–Kendall (MK) test as well as cumulative sum of rank difference (CRD) test. +e results showed that drought occurs in the region regularly (recurrent climate feature), while the trend analysis indicated the trend toward more arid climatic conditions. However, CRD trend analyses showed that the subtrend changed direction toward less drier conditions in the late 1980s and early 1990s. Analyses of SPEI trends in individual months showed a …


Evaluating Future Reservoir Storage In The Rio Grande Using Normalized Climate Projections And A Water Balance Model, Nolan T. Townsend Jul 2019

Evaluating Future Reservoir Storage In The Rio Grande Using Normalized Climate Projections And A Water Balance Model, Nolan T. Townsend

Earth and Planetary Sciences ETDs

We develop and implement new tools for assessing the future of surface water supplies in downstream reaches of the Rio Grande, for which Elephant Butte Reservoir is the major storage reservoir. First, a normalization procedure is developed to adjust natural Rio Grande streamflows simulated by dynamical models in downstream reaches. The normalization accounts for upstream anthropogenic impairments to flow that are not considered in the model, thereby yielding downstream flows closer to observed values and more appropriate for use in assessments of future flows in downstream reaches. The normalization is applied to assess the potential effects of climate change on …


Evaluating Fluid Fluxes From Deep-Sea Seepage Habitats, Leigha E. Peterson Jul 2019

Evaluating Fluid Fluxes From Deep-Sea Seepage Habitats, Leigha E. Peterson

Electronic Theses and Dissertations

The permanently dark deep-sea, located at oceanic water depths greater than 200 m, represents the largest potential habitat space on Earth. The physicochemical conditions of the planet’s largest biome are tightly coupled to the exchange of matter and energy from terrestrial and sea-floor end-members. In fact, global ocean and climate systems are significantly impacted by deep-sea processes. Seafloor vents and seeps appear to act as geologic exchange conduits, returning recycled materials to the hydrosphere to sustain another generation of life. Despite submarine seepage having control on global elemental cycling, it is estimated that less than 1% of the deep-sea has …


An Estimation Of Lower Tropospheric Mixing Derived From Inverse Modeling Of Boundary Layer Water Vapor Isotopologues On Graciosa Island, Azores, Jacquelyn M. Delp Jul 2019

An Estimation Of Lower Tropospheric Mixing Derived From Inverse Modeling Of Boundary Layer Water Vapor Isotopologues On Graciosa Island, Azores, Jacquelyn M. Delp

Earth and Planetary Sciences ETDs

Recent studies have shown water vapor isotopologues to be sensitive tracers of mixing processes that govern low-cloud feedback in climate models. In this study, we develop an inverse model (MBL Mix inverse model) that uses one year of isotope and humidity observations from Graciosa Island, Azores to estimate mixing for four seasons. We show the dry end-member of the model, the lower free troposphere (LFT), can be represented using Rayleigh fractionation. Isotope observations from Graciosa Island are compared to other field locations to discuss controls on isotopic variability other than mixing. Output from the MBL Mix inverse model shows the …


Sources And Chemical Stability Of Soil Organic Carbon Along A Salinity Gradient And A Chronosequence Of Created Brackish Marshes In Coastal Louisiana, Megan L. Kelsall Jul 2019

Sources And Chemical Stability Of Soil Organic Carbon Along A Salinity Gradient And A Chronosequence Of Created Brackish Marshes In Coastal Louisiana, Megan L. Kelsall

LSU Master's Theses

Tidal marshes have been recognized for providing a number of important ecological services including soil carbon sequestration. However, the loss of tidal marsh habitat due to climate change and anthropogenic stressors exposes previously stored soil organic carbon (SOC) to oxidation. The vulnerability of SOC to oxidation depends on its chemical stability and environmental conditions limiting decomposition. Labile organic carbon (LC), decomposes quickly unless abiotic conditions limit decomposition. Recalcitrant organic carbon (RC) decomposes slower and is stored for longer time periods. Predicting long-term storage of SOC is complicated by the potential for multiple SOC sources, differences in chemical stability, and variation …


Sediment Monitoring To Support Modeling A Reservoir Sediment Flush On A Sand-Bed River In Northern Nebraska, Nathaniel J. Schaepe, Paul M. Boyd Jul 2019

Sediment Monitoring To Support Modeling A Reservoir Sediment Flush On A Sand-Bed River In Northern Nebraska, Nathaniel J. Schaepe, Paul M. Boyd

United States Geological Survey: Water Reports and Publications

The United States Geological Survey (USGS) in cooperation with the United States Army Corps of Engineers (USACE), monitored a sediment flush event from Spencer Dam located on the Niobrara River near Spencer, Nebraska, during the fall of 2014. Data collected during the flush was used to validate a one-dimensional sediment transport model developed by the USACE. The USACE surveyed 26 cross sections within the reservoir and as far as 1 kilometer (km) upstream from the reservoir pool to about 10 km downstream from the dam before and after the flushing event to measure erosion and deposition. They also collected surficial …


The Prairie Post Quarterly Newsletter Of The High Plains Regional Climate Center- July 2019, Natalie Umphlett, Rezaul Mamood, Paul Flanagan, Emily Brown, Gannon Rush, Crystal J. Stiles Jul 2019

The Prairie Post Quarterly Newsletter Of The High Plains Regional Climate Center- July 2019, Natalie Umphlett, Rezaul Mamood, Paul Flanagan, Emily Brown, Gannon Rush, Crystal J. Stiles

Prairie Post: Quarterly Newsletter of the High Plains Regional Climate Center

Inside this issue:

Message from the director........................................1

Staff spotlight...........................1

Spirit Lake workshop..............2

Product highlight....................3

Outreach events......................3

Research highlight..................4

Update on regional climate conditions..................................4

Northern Plains drought assessment................................5

Recent and upcoming travel and activities.............................6


Droughtscape, Fall 2019, Cory Matteson Jul 2019

Droughtscape, Fall 2019, Cory Matteson

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Contents

From the Director

Quarterly drought summary

Quarterly drought impacts

Ranchers delayed response to drought

Drought Monitor celebrates 20 years

Drought Monitor state impact tables

Directorcontributesto U.N.droughtproject

Updated Drought Risk Atlas

New fact sheet lists recovery resources


Lipid Biomarkers Of Bering And Chukchi Sea Euphausiids And Their Application To Diet History, Rachel L. Pleuthner Jul 2019

Lipid Biomarkers Of Bering And Chukchi Sea Euphausiids And Their Application To Diet History, Rachel L. Pleuthner

OES Theses and Dissertations

In the eastern Bering Sea, Thysanoessa raschii are the most abundant krill species and a keystone trophic member that serve as both an important grazer and link to upper level consumers. In this system krill experience large annual variation in food resources, especially during ice advance and retreat; multiple lipid classes are used to temper the effects of those fluctuations, as well as to fuel reproduction and growth. Two shipboard feeding experiments that occurred during late spring and early summer of 2010, respectively, monitored the lipid retention in adult T. raschii and examined the fluctuation of specific lipid biomarkers under …


The Evolution Of The El Niño-Southern Oscillation And Tropical Pacific Climate Across The Last Deglaciation, Ryan Hunter Glaubke Jul 2019

The Evolution Of The El Niño-Southern Oscillation And Tropical Pacific Climate Across The Last Deglaciation, Ryan Hunter Glaubke

OES Theses and Dissertations

The El Niño – Southern Oscillation (ENSO) is the largest interannual component of Earth’s climate system, capable of exerting significant influence over global climate patterns that affect communities around the globe. Nevertheless, a comprehensive understanding of the ENSO system and its relationship to tropical Pacific climate dynamics remains unclear. Although new paleoceanographic proxies have shown promise in in their ability to constrain past ENSO change, little is known about how ENSO varied in response to millennial-scale climate events over the last 25,000 years. Here, I present new records of tropical Pacific mean state and ENSO variability over the last 25,000 …


Droughtscape, Summer 2019, Cory Matteson Jul 2019

Droughtscape, Summer 2019, Cory Matteson

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Contents

From the Director

Quarterly drought summary

Quarterly drought impacts

NDMC welcomes African visitors

Ready for Drought game debuts

U.S. Virgin Islands added to USDM

Australian programmer visits NDMC

Upcoming events

Partnerships with NDMC extended


Major And Trace Element Analyses For Studying Oceanic Crustal Construction And Ridge Morphology Along The Kane–Atlantis Supersegment Of The Mid-Atlantic Ridge, Yitong Lyu Jul 2019

Major And Trace Element Analyses For Studying Oceanic Crustal Construction And Ridge Morphology Along The Kane–Atlantis Supersegment Of The Mid-Atlantic Ridge, Yitong Lyu

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

Faulting style along slow-spreading ridge segments exerts a major control over oceanic crustal construction and ridge morphology. Seafloor spreading along slow-spreading ridges is classified into asymmetrical detachment faulting and symmetrical spreading styles. Magma supply variations may influence the formation of symmetric versus asymmetric segments, but the factors that derive such variations remain unclear. We present U and Th concentration data by isotope dilution for basalts from 24 to 30 oN MAR, of which 18 samples were retrieved from detachment faulted and 10 from symmetrical segments. The U-Th concentration results from this study are further compiled with prior published data …


Evaluation Of Viirs Nightfire Product And Comparison With Modis And Viirs Active Fire Products In A Russian Gas Flaring Region, Ambrish Sharma Jul 2019

Evaluation Of Viirs Nightfire Product And Comparison With Modis And Viirs Active Fire Products In A Russian Gas Flaring Region, Ambrish Sharma

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

Gas flaring is a commonly used practice for disposing of waste gases emerging from industrial oil drilling and production processes. It is a serious environmental and economic hazard with adverse impacts on air quality, climate, and the public health. Accurate determination of flare locations and estimation of associated emissions are therefore of prime importance. Recently developed Visible Infrared Imaging Radiometer Suite (VIIRS) Nightfire product (VNF) has shown remarkable efficiency in detecting gas flares globally, owing primarily to its use of Shortwave Infrared (SWIR) band in its detection algorithm. This study compares and contrast nocturnal hot source detection by VNF to …


Investigation Of Grace-Derived Information On Forest Drought Stress Across The Contiguous Us, Beichen Zhang Jul 2019

Investigation Of Grace-Derived Information On Forest Drought Stress Across The Contiguous Us, Beichen Zhang

School of Natural Resources: Dissertations, Theses, and Student Research

This research derives z-score monthly groundwater storage (GWS) anomalies and z-score monthly root zone soil moisture (RZSM) anomalies from products of Gravity Recovery and Climate Experiment Data Assimilation (GRACE-DA). Z-score monthly GWS and RZSM anomalies are compared to two drought indicators: Standardized Precipitation Index (SPI) and Standardized Precipitation-Evapotranspiration Index (SPEI) to investigate the usefulness of GRACE-DA information to detect drought conditions at tree-ring sites. This study also compares z-score monthly GWS and RZSM anomalies with the Tree Ring Standardized Growth Index (TRSGI) that is resampled by bootstrapping to investigate the capability of monitoring forest drought stress. Finally, this research uses …


Groundwater Movement And Interaction With Surface Water Near The Confluence Of The Platte And Elkhorn Rivers, Nebraska, 2016–18, Christopher M. Hobza, Mason J. Johnson, Paul W. Woodward, Kellan R. Strauch, Aaron R. Schepers Jun 2019

Groundwater Movement And Interaction With Surface Water Near The Confluence Of The Platte And Elkhorn Rivers, Nebraska, 2016–18, Christopher M. Hobza, Mason J. Johnson, Paul W. Woodward, Kellan R. Strauch, Aaron R. Schepers

United States Geological Survey: Water Reports and Publications

Document abstract

The State of Nebraska requires a sustainable balance between long-term water supplies and uses of groundwater and surface water and requires Natural Resources Districts to include the effect of groundwater use on surface-water systems as part of their respective integrated management plans. Recent droughts in Nebraska (2000–6; 2012–13) have amplified concerns about the long-term sustainability of groundwater and surface-water resources in the state, and concerns about the effect of groundwater irrigation on both streamflow and the water supplies needed to meet wildlife, recreational, and municipal needs. The lower Platte River provides nearly 100 percent of drinking-water supplies to …


Hourly Precipitation Climatology Of The Southeast United States, Vincent Brown Jun 2019

Hourly Precipitation Climatology Of The Southeast United States, Vincent Brown

LSU Doctoral Dissertations

Precipitation changes are one of the most important potential outcomes of a warming climate because of how essential it is to society and ecosystems. Sub-daily precipitation time series provide more information on precipitation characteristics, particularly frequency, intensity, and duration compared to daily data. In a series of four peer-reviewed manuscripts, this research investigates sub-daily precipitation characteristics from a climatological perspective. The first study introduces a climatology of hourly precipitation for four first-order weather stations across Louisiana, explores possible changes in the hourly precipitation distribution, and links winter Gulf of Mexico sea surface temperatures to the frequency of hours with precipitation. …


The Antiquity Of The Sahara Desert: New Evidence From The Mineralogy And Geochemistry Of Pliocene Paleosols On The Canary Islands, Spain, Daniel R. Muhs, Joaquín Meco, James R. Budahn, Gary L. Skipp, Juan F. Betancort, Alejandro Lomoschitz Jun 2019

The Antiquity Of The Sahara Desert: New Evidence From The Mineralogy And Geochemistry Of Pliocene Paleosols On The Canary Islands, Spain, Daniel R. Muhs, Joaquín Meco, James R. Budahn, Gary L. Skipp, Juan F. Betancort, Alejandro Lomoschitz

United States Geological Survey: Staff Publications

The Sahara is the largest warm desert in the world, but its age has been controversial, with estimates ranging from Miocene to Holocene. Mineralogical and geochemical data show that paleosols of Pliocene to mid- Pleistocene age on Fuerteventura and Gran Canaria in the Canary Islands have developed in part from inputs of dust from Africa. These paleosols contain quartz and mica, minerals that are abundant in African dust but are rare in the basaltic rocks that dominate the Canary Islands. Trace elements with minimal mobility, Sc, Cr, Hf, Th, and Ta as well as the rare earth elements, show that …


Climate Change Impacts On Winter Wheat Yield In Northern China, Xiu Geng, Fang Wang, Wei Ren, Zhixin Hao Jun 2019

Climate Change Impacts On Winter Wheat Yield In Northern China, Xiu Geng, Fang Wang, Wei Ren, Zhixin Hao

Plant and Soil Sciences Faculty Publications

Exploring the impacts of climate change on agriculture is one of important topics with respect to climate change. We quantitatively examined the impacts of climate change on winter wheat yield in Northern China using the Cobb–Douglas production function. Utilizing time-series data of agricultural production and meteorological observations from 1981 to 2016, the impacts of climatic factors on wheat production were assessed. It was found that the contribution of climatic factors to winter wheat yield per unit area (WYPA) was 0.762–1.921% in absolute terms. Growing season average temperature (GSAT) had a negative impact on WYPA for the period of 1981–2016. A …


Incorporating Antecedent Soil Moisture Into Streamflow Forecasting, Abdoul Oubeidillah, Glenn Tootle, Thomas Piechota Jun 2019

Incorporating Antecedent Soil Moisture Into Streamflow Forecasting, Abdoul Oubeidillah, Glenn Tootle, Thomas Piechota

Mathematics, Physics, and Computer Science Faculty Articles and Research

This study incorporates antecedent (preceding) soil moisture into forecasting streamflow volumes within the North Platte River Basin, Colorado/Wyoming (USA). The incorporation of antecedent soil moisture accounts for infiltration and can improve streamflow predictions. Current Natural Resource Conservation Service (NRCS) forecasting methods are replicated, and a comparison is drawn between current NRCS forecasts and proposed forecasting methods using antecedent soil moisture. Current predictors used by the NRCS in regression-based streamflow forecasting include precipitation, streamflow persistence (previous season streamflow volume) and snow water equivalent (SWE) from SNOTEL (snow telemetry) sites. Proposed methods utilize antecedent soil moisture as a predictor variable in addition …


Umphlett Qci June 2019, Natalie Umphlett Jun 2019

Umphlett Qci June 2019, Natalie Umphlett

High Plains Regional Climate Center: Staff Publications

Highlights for the Basin

Temperature and Precipitation Anomalies

Soil Moisture Conditions

Delayed/Prevented Planting

Impacts to Cattle

Damage to Infrastructure

Temperature

Precipitation


An Analysis Of Differential Reflectivity Arc Characteristics In 109 Supercell Storms, Matthew Wilson Jun 2019

An Analysis Of Differential Reflectivity Arc Characteristics In 109 Supercell Storms, Matthew Wilson

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

Differential reflectivity (ZDR)arcs are one of the most prominent dual-polarization features of supercell storms, and are manifest as an arc-shaped area of high ZDR along a supercell’s forward flank reflectivity gradient. Since previous modelling studies have hypothesized that the magnitude of the drop-size sorting by the storm-relative wind which creates the arc signature is related to the strength of the low-level shear and SRH in a storm’s environment, the presence of a strong ZDR arc is often said to indicate that a storm may have the potential to develop strong low-level rotation and potentially become tornadic. …


Next-Generation Rainfall Idf Curves For The Virginian Drainage Area Of Chesapeake Bay, Xixi Wang, Xiaomin Yang, Zhaoyi Cai Jun 2019

Next-Generation Rainfall Idf Curves For The Virginian Drainage Area Of Chesapeake Bay, Xixi Wang, Xiaomin Yang, Zhaoyi Cai

Civil & Environmental Engineering Faculty Publications

Probability-based intensity-duration-frequency IDF curves are needed but currently lacking for Department of Defense DoD to construct and manage its infrastructure in changing climate. The objectives of this project were to 1 develop an innovative approach for considering rainfall non-stationarity in developing such IDF curves and 2 apply this approach to the state of Virginia. In this regard, the observed data on 15-min rainfall at 57 gauges and the precipitations projected by twelve pairs of Regional Climate Model RCM and Global Circulation Model GCM were used. For a given gauge or watershed, in terms of fitting the empirical exceedance probabilities, a …


Assessment Of Agricultural Drought Considering The Hydrological Cycle And Crop Phenology In The Korean Peninsula, Chul-Hee Lim, Seung Hee Kim, Jong Ahn Chun, Menas Kafatos, Woo-Kyun Lee May 2019

Assessment Of Agricultural Drought Considering The Hydrological Cycle And Crop Phenology In The Korean Peninsula, Chul-Hee Lim, Seung Hee Kim, Jong Ahn Chun, Menas Kafatos, Woo-Kyun Lee

Mathematics, Physics, and Computer Science Faculty Articles and Research

Hydrological changes attributable to global warming increase the severity and frequency of droughts, which in turn affect agriculture. Hence, we proposed the Standardized Agricultural Drought Index (SADI), which is a new drought index specialized for agriculture and crops, and evaluated current and expected droughts in the Korean Peninsula. The SADI applies crop phenology to the hydrological cycle, which is a basic element that assesses drought. The SADI of rice and maize was calculated using representative hydrological variables (precipitation, evapotranspiration, and runoff) of the crop growing season. In order to evaluate the effectiveness of SADI, the three-month Standardized Precipitation Index, which …


Numerical Modeling Of Wave Dynamics And Sediment Transport Near The Mississippi Birdfoot Delta And Barataria Estuary, Soroush Sorourian May 2019

Numerical Modeling Of Wave Dynamics And Sediment Transport Near The Mississippi Birdfoot Delta And Barataria Estuary, Soroush Sorourian

LSU Doctoral Dissertations

The Barataria Basin is a large estuarine system in Southeastern Louisiana, connected to the Gulf of Mexico through a number of inlets, the most important of which is the Barataria Pass. This research examines, during April-June 2010 including both cold front passage and calm summer-time wind regimes, the wave dynamics in this basin and in its major inlets, morphological evolution near the Barataria Pass, and the budgeting and dispersal of the Mississippi River sediment in the birdfoot delta region. An unstructured grid, terrain following, high resolution coupled FVCOM-SWAVE-SED model is employed and validated in this study. The numerical model results …


Land – Atmosphere – Meteorological Coupling Associated With The 2015 Gorkha (M 7.8) And Dolakha (M 7.3) Nepal Earthquakes, Feng Jing, Ramesh P. Singh, Xuhui Shen May 2019

Land – Atmosphere – Meteorological Coupling Associated With The 2015 Gorkha (M 7.8) And Dolakha (M 7.3) Nepal Earthquakes, Feng Jing, Ramesh P. Singh, Xuhui Shen

Mathematics, Physics, and Computer Science Faculty Articles and Research

Multiple parameters (brightness temperature, soil moisture, surface latent heat flux, surface air temperature and carbon monoxide) before and after the 2015 Nepal M7.8 Gorkha main earthquake and M7.3 Dolakha aftershock were analysed using satellite observation data. The thermal anomalies from optical and microwave data appear about two months prior to the 2015 Gorkha earthquake. Some of the parameters show anomalous changes at different altitudes about 20 days prior to the main earthquake event and 10 days prior to the strong aftershock. Our results show that pre-earthquake anomalous signals propagate from the in situ to the top of atmosphere, and the …