Oceanography and Atmospheric Sciences and Meteorology Commons^™

Variations Of Global Ocean Salinity From Multiple Gridded Argo Products, Chao Liu

USF Tampa Graduate Theses and Dissertations

Salinity is one of the fundamental ocean state variables. Variations of ocean salinity can be used to infer changes in the global water cycle and air-sea freshwater exchange. Many institutions have developed gridded Argo products of global coverage. However, the existing gridded salinity products have not yet been dedicatedly intercompare and assessed. In this study, the mean state, annual and interannual variabilities, and decadal changes of ocean salinity from five Argo-based gridded salinity products, available from UK Met Office, JAMSTEC, Scripps Institution of Oceanography, China Second Institute of Oceanography, and International Pacific Research Center, are examined and compared for their …

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

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 …

Circulation, Vol. 24, No. 3, Center For Coastal Physical Oceanography, Eileen Hofmann, Brynn Pecher, Margaret Mulholland

CCPO Circulation

Summer 2019 issue of CCPO Circulation featuring article, "Combining Forces to Understand Harmful Algal Bloom Dynamics," by Eileen Hofmann, Brynn Pecher, and Margie Mulholland.

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

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

Aviation Weather Products In General Aviation : Interpretability And Usability Research Trends, Jacqueline Mcsorley, Jayde King, Beth Blickensderfer

General Aviation Weather Display Interpretation

• Introduction
• Current Study
• Trends
• Summary
• Conclusion

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

Where People Meet The Muck: An Integrated Assessment Of Beach Muck And Public Perception At The Bay City State Recreation Area, Saginaw Bay, Lake Huron, Donna R. Kashian, Avik Basu, Joseph Depinto, Jason Duvall, Ray Fahlsing, Darrin Hunt, Frank Lupi, Bretton Joldersma

Biological Sciences Faculty Research Publications

In several regions of the Great Lakes, including Saginaw Bay, the proliferation of muck, decaying organics largely from aquatic plants such as Cladophora, has washed ashore, and is blamed for negatively affecting water quality and economic losses in the region. The current view is that excess nutrient loading into the system is a leading cause of this type of organic debris, though changes in food web dynamics may also be a contributing factor. Through an Integrated Assessment (IA) framework, we summarized the current state of knowledge on the causes and consequences of muck conditions at the Bay City State Recreation …

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

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

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 …

Leading-Edge Vortices Over Swept-Back Wings With Varying Sweep Geometries, William B. Lambert, Mathew J. Stanek, Roi Gurka, Erin E. Hackett

Marine Science

Micro air vehicles are used in a myriad of applications, such as transportation and surveying. Their performance can be improved through the study of wing designs and lift generation techniques including leading-edge vortices (LEVs). Observation of natural fliers, e.g. birds and bats, has shown that LEVs are a major contributor to lift during flapping flight, and the common swift (Apus apus) has been observed to generate LEVs during gliding flight. We hypothesize that nonlinear swept-back wings generate a vortex in the leadingedge region, which can augment the lift in a similar manner to linear swept-back wings (i.e. delta wing) during …

The Effects Of Economic Factors And Groundwater Policies On The Timing Of Well Drilling, Qianyu Zhang

Department of Agricultural Economics: Dissertations, Theses, and Student Research

Understanding the factors that affect farmers’ irrigation decisions is critical for a better groundwater management. This study addresses the question of how economic, agronomic, and policy variables affect the timing of irrigation adoption in Nebraska. The key contribution of this paper is to identify farmers’ strategic responses to a particular type of policy intervention, a moratorium on well drilling. Our results estimate how farmers respond when a moratorium is announced but not enforced yet, and when neighboring areas implement a moratorium, which we refer as pre-regulation effect and policy spillover effect, respectively. Results show that farmers are more likely to …

2019 July - Tennessee Monthly Climate Report, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Monthly Reports

No abstract provided.

The Role Of The Southern Ocean On Global Ocean Circulation And Climate, Brady Scott Ferster

Theses and Dissertations

The Southern Ocean (SO) is a unique and highly dynamic region with strong temperature and salinity gradients. A comparison between satellite-derived salinity and observations indicates strong differences along coastal boundaries, areas of low temperature, and regions of strong currents. Although differences throughout much of the SO are shown to be negligible, resolution and smoothing in the products create large biases in horizontal gradients and errors in estimating the water cycle. The three-dimensional movement of water within the SO plays an important role in the global Meridional Overturning Circulation (MOC), where the Southern Hemisphere westerlies drive both zonal and meridional transports …

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 …

Nutrient Controls Over Cyanobacterial Synthesis Of The Neurotoxin Β-N-Methylamino-L-Alanine (Bmaa) And Its Potential Accumulation In The Blue Crab (Callinectes Sapidus), Madeline M. Hummel

OES Theses and Dissertations

Cyanobacteria are known to produce a variety of toxins that negatively impact both aquatic and terrestrial organisms. One putative neurotoxic compound is the non-protein amino acid β-N-methylamino-L-alanine (BMAA), which has epidemiological linkages to the development of several human neurological diseases. Three cyanobacterial species thought to produce BMAA —Microcystis aeruginosa, Synechococcus bacillaris, and Nostoc sp. —were grown in nutrient replete cultures to examine its synthesis and cellular distribution over a growth cycle. Production of BMAA was also examined in nutrient (nitrogen and phosphorus) deplete cultures of Microcystis aeruginosa. In addition, natural assemblages of phytoplankton dominated by …

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 …

Application Of The Optimal Estimation Method (Oem) To Retrieve Relative Humidity From Raman Lidar Backscatter Measurements., Shayamila N. Mahagammulla Gamage, Robert Sica, Alexander Haefele

Western Research Forum

Accurate measurements of relative humidity (RH) vertical profiles in the atmosphere is important for understanding the earth's weather and the climate system. RH represent the current state of the water vapor in the atmosphere with respect to the ambient air related to saturation. Even minor changes of the RH in the lower atmosphere has a large impact of the global circulation and cloud formation. Due to its high variability RH measurements in the lower atmosphere is significantly challenging. Raman lidar is one of the potential tools that can provide vertical profiles of RH. Typically, temperature and water vapor mixing ratios …