Oceanography and Atmospheric Sciences and Meteorology Commons^™

Identifying The Microphysical Sensitivities Of Mesoscale And Synoptic Precipitation Using An Ensemble Framework, Lauriana Gaudet

Legacy Theses & Dissertations (2009 - 2024)

Through ensemble sensitivity analysis, this dissertation aims to identify the amount of forecast uncertainty that stems from the representation of mixed-phase cloud microphysics within the Weather Research and Forecasting Model (WRF). The first research thrust focuses on how the evolution of ice crystal shape and choice of ice nucleation parameterization in the Adaptive Habit Microphysics Model (AHM) influences the lake-effect storm that occurred during Intensive Operating Period 4 (IOP4) of the Ontario Winter Lake Effect Systems (OWLeS) Field Campaign. This localized snowstorm produced total liquid-equivalent precipitation amounts up to 17.92 mm during a 16-hour time period, providing a natural laboratory …

The Sensitivity Of Convection To Boundary Layer Parameterization In Hurricanes Harvey And Irma 2017, Dylan Card

Legacy Theses & Dissertations (2009 - 2024)

Tropical cyclones (TCs) pose a significant threat to life and property, and exhibit many severe weather hazards as they make landfall, such as storm surge, strong winds, flooding rains, and tornadoes. TC convection is associated with nearly all of these hazards, which can extend hundreds of kilometers inland; thus, understanding the characteristics and organization of convective cells is important to mitigating risk. Observational studies have noted that TC convection tends to organize downshear and that rotating thunderstorms tend to occur in the downshear-right quadrant of the TC. Modeling studies have also shown that convective cells tend to form upshear right …

Aerosol And Terrain Effects On Winter Cloud And Precipitation Over New York State, Yuyi Du

Legacy Theses & Dissertations (2009 - 2024)

Prediction of regional weather and climate regarding precipitation for a region such as the Northeast US with its complex terrain and aerosol environment constitutes a major challenge. Furthermore, complex thermodynamic structures occur in and around New York State (NYS) owing to its complex topography paired with its coastal regions, ultimately affecting cloud and precipitation microphysics. The microphysical processes within the weather systems that produce orographic precipitation are not fully understood. These processes include, but are not limited to, liquid-ice interactions, ice growth through vapor deposition, riming, and aggregation, cloud-aerosol interactions, and melting and refreezing upon sedimentation to the surface. These …

An Examination Of The Arctic Environment And Arctic Cyclones During Periods Of Low And High Forecast Skill Of The Synoptic-Scale Flow, Kevin Biernat

Legacy Theses & Dissertations (2009 - 2024)

This dissertation compares Arctic environmental conditions and Arctic cyclones (ACs) between periods of low and high forecast skill of the synoptic-scale flow over the Arctic during summer, hereafter referred to as low-skill periods and high-skill periods, respectively. This dissertation also examines features and processes influencing the evolution and forecast skill of selected categories of ACs.

Physical Characteristics And Microphysical Processing Of Atmospheric Aerosol In Rural And Urban New York State, Joseph Marto

Legacy Theses & Dissertations (2009 - 2024)

Atmospheric aerosol has profound impacts on air quality, though particles of differing sizes can have profoundly different characteristics which are understated when measurements are reported as a single parameter (typically number concentration or total mass). To address some of these concerns and to better understand the nature of atmospheric aerosol, continuous particle size distributions have been measured at two sites in New York State. Measurement was performed for particle diameters between 7.6nm - 20µm at Pinnacle State Park (Addison, New York; March 2017-April 2018) and Queens College (May 2018-September 2019) at a 5-minute time resolution. At Pinnacle State Park, aerosol …

Process-Based Evaluation Of Stochastic Perturbed Parameterization Tendencies On Ensemble Forecasts Of Heavy Rainfall Events, Kevin Michael Lupo

Legacy Theses & Dissertations (2009 - 2024)

Stochastic model error schemes, such as the stochastic perturbed parameterization tendencies (SPPT) and independent SPPT (iSPPT) schemes, have become an increasingly utilized method to represent model error associated with uncertain subgrid-scale processes in ensemble prediction systems (EPSs). While much of the current literature focuses on how stochastic methods influence ensemble skill, relatively less attention is given to the processes by which these schemes lead to forecast variability. In this vein, this dissertation examines the physical processes by which the application of SPPT and iSPPT to the microphysics, planetary boundary layer (PBL), and radiation parameterization schemes yields rainfall forecast variability. These …

Evaluating The Performance Of National Water Model Snow Simulations In The Northeastern United States Using Advanced Mesonet Observations, Patrick William Naple

Legacy Theses & Dissertations (2009 - 2024)

Snow is a critical component in the hydrologic cycle and critical to runoff in many regions. While not as deep or persistent as snow in the Western United States (WUS) , snow in the Northeastern US (NEUS) is critical to water resource management and flood forecasting. For hydrological applications, snow is simulated using coupled hydrology models . These models couple numerical weather models, land surface models, and channel routing models that simulate water transport. One such coupled hydrology model is the NOAA National Water Model (NWM), implemented in 2016. The NWM runs a specific configuration of the WRF-Hydro community model. …

A Comparison Of The Upscale Influence Of Various Planetary Boundary Layer Turbulence Parameterizations On The Evolution Of Extratropical Cyclones, Matthew Vaughan

Legacy Theses & Dissertations (2009 - 2024)

Subgrid-scale turbulence in numerical weather prediction models is typically handled by a PBL parameterization. These schemes attempt to represent turbulent mixing processes occurring below the resolvable scale of the model grid in the vertical direction, and they act upon temperature, moisture, and momentum within the boundary layer. This dissertation utilizes idealized and full-physics numerical model simulations to understand how variations in turbulent mixing parameterizations may influence sensible weather forecasts of baroclinic cyclones across a variety of spatial and temporal scales. Furthermore, a primary pathway through which PBL turbulence projects upscale during baroclinic cyclone events is identified using a combination of …

Pesticide Occurrence And Persistence Entering Recreational Lakes In Watersheds Of Varying Land Uses, Jessica Satiroff, Tiffany Messer, Aaron R. Mittelstet, Daniel D. Snow

Nebraska Water Center: Faculty Publications

Currently little is known of newer pesticide classes and their occurrence and persistence in recreational lakes. Therefore, the objectives of this study were to (1) assess average pesticide concentrations and loadings entering recreational lakes in three mixed land use watersheds throughout the growing season, (2) evaluate pesticide persistence longitudinally within the lakes, and (3) perform an ecotoxicity assessment. Six sampling campaigns were conducted at three lakes from April through October 2018 to measure the occurrence and persistence during pre, middle, and post growing season. Polar organic chemical integrative samplers (POCIS) were placed in streams near lake inlets and monthly samples …

Occurrence Of Arsenite In Surface And Groundwater Associated With A Perennial Stream Located In Western Nebraska, Usa, Arindam Malakar, Rajesh Singh, Jeffrey Westrop, Karrie A. Weber, Christopher N. Elofson, Manish Kumar, Daniel D. Snow

Nebraska Water Center: Faculty Publications

Dissolved arsenic typically results from chemical weathering of arsenic rich sediments and is most often found in oxidized forms in surface water. The mobility of arsenic is controlled by its valence state and also by its association with iron oxides minerals, the forms of which are both influenced by abiotic and biotic processes in aqueous environment. In this study, speciation methods were used to measure and confirm the presence of reduced arsenic species in the surface water of Frenchman creek, a gaining stream that crosses the Colorado- Nebraska border. Selective extraction analysis of aquifer and stream bed sediments shows that …

Droughtscape, Winter 2021, National Drought Mitigation Center

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

DroughtScape, Winter 2021

Climate Change Impacts On Wind Energy Generation In Ireland, Eadaoin Doddy Clarke, Conor Sweeney, Frank Mcdermott, Seánie Griffin, Joao Monteiro Correia, Paul Nolan, Laura Cooke

Articles

An ensemble of high-resolution regional climate model simulation data is used to examine the impacts of climate change on offshore and onshore wind energy genera- tion in Ireland. Two Representative Concentration Pathway (RCP) scenarios (RCP 4.5 and 8.5) are analysed for the mid-term (2041–2060) and the long-term (2081–2100) future. Wind energy is projected to decrease (≤2%) overall in future climate scenarios. Changes are evident by mid-century and are more pronounced by late 21st century, particularly for RCP 8.5 offshore. Seasonally, wind energy is projected to decrease by less than 6% in summer and to increase slightly in winter (up to …

A Novel Binary Pipette Splitting Sediment Subsampling Method For Improving Reproducibility In Laser-Diffraction Particle-Size Analysis, Zhixiong Shen, Nicholas Conway, Till J.J. Hanebuth

Marine Science

Laser-diffraction analysis has been established as one of the standard methods for particle-size distribution (PSD) measurement. However, the uncertainty when analyzing naturally heterogeneous sediment is poorly constrained for the lack of control on one of its largest error sources simply originating from subsampling. Here, we introduce a novel subsampling method, binary pipette splitting (BPS), and verify its precision by using sediment samples from ten flood-layer deposits that have formed in the wake of Hurricane Florence (2018). The BPS approach avoids extracting from only a fixed part of the suspended fluid but considers all the suspended sediment, resulting in the generation …

Naturally Occurring Rock Type Influences The Settlement Of Fucus Spiralis L. Zygotes, William G. Ambrose, Paul E. Renaud, David C. Adler, Robert L. Vadas

Marine Science

The settlement of spores and larvae on hard substrates has been shown to be influenced by many factors, but few studies have evaluated how underlying bedrock may influence recruitment. The characteristics of coastal rock types such as color, heat capacity, mineral size, and free energy have all been implicated in settlement success. We examined the influence of naturally occurring rock types on the initial attachment of zygotes of the brown alga Fucus spiralis Linnaeus 1753. We also assessed the dislodgment of zygotes on four bedrock types after initial attachment in laboratory experiments using wave tanks. Settling plates were prepared from …

Aquatic Macrophyte Communities In Five Sibley County (Minnesota) Lakes And The Factors That Affect Their Distribution, Samuel A. Schmid

All Graduate Theses, Dissertations, and Other Capstone Projects

The purposes of this study are to 1) quantify the shifts in the macrophyte community structure of five lakes in Sibley County, and 2) to assess the relationships between the macrophyte communities and abiotic factors in these five lakes. In both the early and late growing season of 2019, point-intercept surveys were conducted on High Island Lake, Titlow Lake, Schilling Lake, Silver Lake, and Clear Lake. At each point, water depth was recorded, and all macrophytes sampled were identified and recorded as “present.” There was not a late season survey conducted for High Island Lake in 2019 due to a …

Factors Determining Seagrass Blue Carbon Across Bioregions And Geomorphologies, Ines Mazarrasa, Paul Lavery, Carlos M. Duarte, Anna Lafratta, Catherine E. Lovelock, Peter I. Macreadie, Jimena Samper-Villarreal, Cristian Salinas, Christian J. Sanders, Stacey Trevathan-Tackett, Mary Young, Andy Steven, Oscar Serrano

Research outputs 2014 to 2021

Seagrass meadows rank among the most significant organic carbon (C_org) sinks on earth. We examined the variability in seagrass soil C_org stocks and composition across Australia and identified the main drivers of variability, applying a spatially hierarchical approach that incorporates bioregions and geomorphic settings. Top 30 cm soil C_org stocks were similar across bioregions and geomorphic settings (min-max: 20–26 Mg C_org ha⁻¹), but meadows formed by large species (i.e., Amphibolis spp. and Posidonia spp.) showed higher stocks (24–29 Mg C_org ha⁻¹) than those formed by smaller species (e.g., Halodule, Halophila, …

Eddy-Driven Transport Of Particulate Organic Carbon-Rich Coastal Water Off The West Antarctic Peninsula, Renato M. Castelao, Michael S. Dinniman, Caitlin M. Amos, John M. Klinck, Patricia M. Medeiros

CCPO Publications

The Southern Ocean is characterized by high eddy activity and high particulate organic carbon (POC) content during summer, especially near Antarctica. Because it encircles the globe, it provides a pathway for inter‐basin exchange. Here, we use satellite observations and a high‐resolution ocean model to quantify offshore transport of coastal water rich in POC off the West Antarctic Peninsula. We show that nonlinear cyclonic eddies generated near the coast often trap coastal water rich in POC during formation before propagating offshore. As a result, cyclones found offshore that were generated near the coast have on average higher POC content in their …

Riverine Carbon Cycling Over The Past Century In The Mid‐Atlantic Region Of The United States, Yuanzi Yao, Hanqin Tian, Shufen Pan, Raymond G. Najjar, Marjorie A.M. Friedrichs, Zihao Bian, Hong-Yi Li, Eileen E. Hofmann

CCPO Publications

The lateral transport and degassing of carbon in riverine ecosystems is difficult to quantify on large spatial and long temporal scales due to the relatively poor representation of carbon processes in many models. Here, we coupled a scale‐adaptive hydrological model with the Dynamic Land Ecosystem Model to simulate key riverine carbon processes across the Chesapeake and Delaware Bay Watersheds from 1900 to 2015. Our results suggest that throughout this time period riverine CO₂ degassing and lateral dissolved inorganic carbon fluxes to the coastal ocean contribute nearly equally to the total riverine carbon outputs (mean ± standard deviation: 886 ± …

Impacts Of Multiple Environmental Changes On Long‐Term Nitrogen Loading From The Chesapeake Bay Watershed, Shufen Pan, Zihao Bian, Hanqin Tian, Yuanzhi Yao, Raymond G. Najjar, Marjorie A.M. Friedrichs, Eileen E. Hofmann, Rongting Xu, Bowen Zhang

CCPO Publications

Excessive nutrient inputs from land, particularly nitrogen (N), have been found to increase the occurrence of hypoxia and harmful algal blooms in coastal ecosystems. To identify the main contributors of increased N loading and evaluate the efficacy of water pollution control policies, it is essential to quantify and attribute the long‐term changes in riverine N export. Here, we use a state‐of‐the‐art terrestrial–aquatic interface model to examine how multiple environmental factors may have affected N export from the Chesapeake Bay watershed since 1900. These factors include changes in climate, carbon dioxide, land use, and N inputs (i.e., atmospheric N deposition, animal …

Global Connectivity Of Southern Ocean Ecosystems, Eugene J. Murphy, Nadine M. Johnston, Eileen E. Hofmann, Richard A. Phillips, Jennifer A. Jackson, Andrew J. Constable, Sian F. Henley, Jessica Melbourne-Thomas, Rowan Trebilco, Rachel D. Cavanagh, Geraint A. Tarling, Ryan A. Saunders, David K.A. Barnes, Daniel P. Costa, Stuart P. Corney, Ceridwen I. Fraser, Juan Höfer, Kevin A. Hughes, Chester J. Sands, Sally E. Thorpe, Philip N. Trathan, José C. Xavier

CCPO Publications

Southern Ocean ecosystems are globally important. Processes in the Antarctic atmosphere, cryosphere, and the Southern Ocean directly influence global atmospheric and oceanic systems. Southern Ocean biogeochemistry has also been shown to have global importance. In contrast, ocean ecological processes are often seen as largely separate from the rest of the global system. In this paper, we consider the degree of ecological connectivity at different trophic levels, linking Southern Ocean ecosystems with the global ocean, and their importance not only for the regional ecosystem but also the wider Earth system. We also consider the human system connections, including the role of …

Confronting Racism To Advance Our Science, Peter Zeitler, Ana P. Barros, Thorsten W. Becker, Eric A. Davidson, Bethany L. Ehlmann, Nicholas Gruber, Eileen E. Hofmann, Mary K. Hudson, Tissa H. Illangasekare, Sarah M. Kang, Paola Malanotte-Rizzoli, Margaret Moerchen, Francis Nimmo, Tom Parsons, Vincent J.M. Salters, Bjorn Stevens, Susan Trumbore, Donald J. Wuebbles, Tong Zhu

CCPO Publications

As individuals serving on the AGU Advances editorial board, we condemn racism, affirm that Black Lives Matter, and recognize that inequality is built into the systems that have allowed us to prosper. We aim to persistently foster discussion about racism, inequity, and the need to make our community more diverse and inclusive. This will help AGU Advances do a better job in publishing important science that inclusively reflects the ideas and contributions of all in our community.

Thank You To Our 2020 Peer Reviewers, Susan Trumbore, Ana P. Barros, Thorsten W. Becker, Eric A. Davidson, Bethany L. Ehlmann, Nicolas Gruber, Eileen Hofmann, Mary K. Hudson, Tissa H. Illangasekare, Sarah Kang, Paola Malanotte-Rizzoli, Alberto Montanari, Francis Nimmo, Tom Parsons, Vincent J.M. Salters, David Schimel, Bjorn Stevens, Donald Wuebbles, Peter Zeitler, Tong Zhu

CCPO Publications

No abstract provided.

Measuring Winds From Space To Reduce The Uncertainty In The Southern Ocean Carbon Fluxes: Science Requirements And Proposed Mission, Joellen L. Russell, David G. Long, Paul Chang, Madeline Cowell, Enrique Curchitser, Michael S. Dinniman, Charles Fellows, Paul Goodman, Eileen Hofmann, Zorana Jelenak, John Klinck, John P. Krasting, Nicole Suzanne Lovenduski, Marcus Lofverstrom, Matthew R. Mazloff, Shelley Petroy, Anjani Polit, Ernesto Rodriguez, Oscar Schofield, Ad Stoffelen, Ronald J. Stouffer, Rik Wanninkhof, Carl Weimer, Xubin Zeng

CCPO Publications

Strong winds in Southern Ocean storms drive air-sea carbon and heat fluxes. These fluxes are integral to the global climate system and the wind speeds that drive them are increasing. The current scatterometer constellation measuring vector winds remotely undersamples these storms and the higher winds within them, leading to potentially large biases in Southern Ocean wind reanalyses and the fluxes that derive from them. This observing system design study addresses these issues in two ways. First, we describe an addition to the scatterometer constellation, called Southern Ocean Storms -- Zephyr, to increase the frequency of independent observations, better constraining high …

Coral Oxygen Isotopic Records Capture The 2015/2016 El Niño Event In The Central Equatorial Pacific, Gemma K. O'Connor, Kim M. Cobb, Hussein R. Sayani, Alyssa R. Atwood, Pamela R. Grothe, Samantha Stevenson, Et. Al.

Earth and Environmental Sciences

Coral oxygen isotopes (δ18O) from the central equatorial Pacific provide monthly resolved records of El Niño-Southern Oscillation activity over past centuries to millennia. However, calibration studies using in situ data to assess the relative contributions of warming and freshening to coral δ18O records are exceedingly rare. Furthermore, the fidelity of coral δ18O records under the most severe thermal stress events is difficult to assess. Here, we present six coral δ18O records and in situ temperature, salinity, and seawater δ18O data from Kiritimati Island (2°N, 157°W) spanning the very strong 2015/16 El Niño event. Local sea surface temperature (SST) anomalies of …

Carbonaceous Matter In The Atmosphere And Glaciers Of The Himalayas And The Tibetan Plateau: An Investigative Review, Chaoliu Li, Fangping Yan, Shichang Kang, Caiqing Yan, Zhaofu Hu, Pengfei Chen, Shaopeng Gao, Chao Zhang, Cenlin He, Susan Kaspari, Aron Stubbins

Geological Sciences Faculty Scholarship

Carbonaceous matter, including organic carbon (OC) and black carbon (BC), is an important climate forcing agent and contributes to glacier retreat in the Himalayas and the Tibetan Plateau (HTP). The HTP – the so-called “Third Pole” – contains the most extensive glacial area outside of the polar regions. Considerable research on carbonaceous matter in the HTP has been conducted, although this research has been challenging due to the complex terrain and strong spatiotemporal heterogeneity of carbonaceous matter in the HTP. A comprehensive investigation of published atmospheric and snow data for HTP carbonaceous matter concentration, deposition and light absorption is presented, …

Examining Co2 Model Observation Residuals Using Act-America Data, Tobias Gerken, Sha Feng, Klaus Keller, Thomas Lauvaux, Joshua P. Digangi, Yonhoon Choi, Bianca Baier, Kenneth J. Davis

School of Integrated Sciences - Faculty Scholarship

An edited version of this paper was published by AGU. Copyright (2021) American Geophysical Union.

Please refer to:
Gerken, Tobias, Sha Feng, Klaus Keller, Thomas Lauvaux, Joshua P. DiGangi, Yonghoon Choi, Bianca Baier, and Kenneth J. Davis. Examining CO2 Model Observation Residuals Using ACT-America Data. Journal of Geophysical Research: Atmospheres 126, no.18 (2021): e2020JD034481. https://doi.org/10.1029/2020JD034481

Atmospheric CO₂ inversion typically relies on the specification of prior flux and atmospheric model transport errors, which have large uncertainties. Here, we used ACT-America airborne observations to compare CO₂ model-observation mismatch in the eastern U.S. and during four climatological seasons for the mesoscale …

Influence Of Iceberg-Discharge Events On The Climate And Circulation Of The Central North Atlantic Ocean During The Last Glaciation, Ava Mcilvaine

Scripps Senior Theses

The repeated occurrence of episodic iceberg-discharge events and abrupt climate change in the North Atlantic Ocean is well-documented for the late Quaternary period. However, much of the evidence for these periods known as Heinrich Events comes from the subpolar region, where deposition can be dominated by ice-rafted debris (IRD) and overwhelm other oceanographic and climatic indicators. Thus, the following analysis of coarse sediment from Integrated Ocean Drilling Program (IODP) Core Site U1313 (41°0.0'N, 32°57.42'W) evaluated ocean cooling related to ice-rafting, water mass migration, and climate change over the approximate last 100,000 years. Site U1313 is located near the North Atlantic …

Development Of Environmental Metabarcoding Analysis For Use In Ecological Studies Of Aquatic Fungal And Oomycete Communities Using Nanopore Sequencing, Douglas Bennett

All Master's Theses

One of several factors contributing to amphibian decline are organisms called water molds (oomycetes), which parasitize and kill amphibian and fish eggs, larvae, and occasionally adults. Amphibian decline is one of the most difficult issues facing ecologists and conservationists to date; half of amphibian species are in severe decline and one third of amphibian species are facing extinction, threatening the stability of ecosystems globally. Multiple oomycete species are known to cause the disease saprolegniasis and contribute to amphibian decline; however, the full range of species involved is not presently known. This study evaluated the Oxford Nanopore minION DNA sequencer (R9.2 …

Effects Of Hydrological And Climatic Variables On Cyanobacterial Blooms In Four Large Shallow Lakes Fed By The Yangtze River, Jian Huang, Qiujin Xu, Xixi Wang, Hao Ji, Edward J. Quigley, Mohamadali Sharbatmaleki, Simeng Li, Beidou Xi, Biao Sun, Caole Li

Civil & Environmental Engineering Faculty Publications

Shallow lakes, one of the most widespread water bodies in the world, are easily shifted to a new trophic state due to external interferences. Shifting hydrologic conditions and climate change can cause cyanobacterial harmful algal blooms (CyanoHABs) in shallow lakes, which pose serious threats to ecological integrity and human health. This study analyzed the effects of hydrologic and meteorological variables on cyanobacterial blooms in Yangtze-connected lakes (Lake Dongting and Poyang) and isolated lakes (Lake Chao and Tai). The results show that (i) chlorophyll-a (Chl-a) concentration tends to decrease exponentially with increasing relative lake level fluctuations (RLLF) and precipitation, but to …

Changes In The Philippine Coastal Environment, Karl H. Szekielda, Ma. Aileen Leah G. Guzman

Environmental Science Faculty Publications

Global warming is progressing at a faster speed than has been estimated earlier in climate forecasting, and the ocean responds rather quickly to global temperature increase. This study uses remotely sensed data that were accessed from the System for Multidisciplinary Research and Applications (NASA Giovanni) to study environmental change in the Philippines’ coast. Monthly averaged sea surface temperature series from around the Philippines indicate that the Philippines follow the global trend in ocean temperature increase and show the increase of about 0.50C within two decades. Despite the high variability in temperature, the linear regressions displayed for all seasons show an …