Climate Commons^™

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 …

Dynamical Downscaling Projections Of Late 21st Century U.S. Landfalling Hurricane Activity, Thomas R. Knutson, Joseph J. Sirutis, Morris A. Bender, Robert E. Tuleya

CCPO Publications

U.S. landfalling tropical cyclone (TC) activity was projected for late 21st century conditions using a two-step dynamical downscaling framework. A regional atmospheric model, run for 27 seasons, generated tropical storm cases. Each storm case was re-simulated (up to 15 days) using the higher resolution GFDL hurricane model. Thirteen CMIP3 or CMIP5 modeled climate change projections were explored as scenarios. Robustness of projections was assessed using statistical significance tests and comparing the sign of changes derived from different models. The proportion of TCs (tropical storms and hurricanes) making U.S. landfall increases for the warming scenarios (by order 50% or more). For …

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 ± …

Constraining 20th‐Century Sea‐Level Rise In The South Atlantic Ocean, Thomas Frederikse, Surendra Adhikari, Tim J. Daley, Sönke Dangendorf, Roland Gehrels, Felix Landerer, Marta Marcos, Thomas L. Newton, Graham Rush, Aimée B.A. Slangen, Guy Wöppelmann

OES Faculty Publications

Sea level in the South Atlantic Ocean has only been measured at a small number of tide-gauge locations, which causes considerable uncertainty in 20th-century sea-level trend estimates in this basin. To obtain a better-constrained sea-level trend in the South Atlantic Ocean, this study aims to answer two questions. The first question is: can we combine new observations, vertical land motion estimates, and information on spatial sampling biases to obtain a likely range of 20th-century sea-level rise in the South Atlantic? We combine existing observations with recovered observations from Dakar and a high-resolution sea-level reconstruction based on salt-marsh sediments from the …

Effects Of Tidal Flooding On Estuarine Biogeochemistry: Quantifying Flood-Driven Nitrogen Inputs In An Urban, Lower Chesapeake Bay Sub-Tributary, Alfonso Macías-Tapia, Margaret R. Mulholland, Corday R. Selden, J. Derek Loftis, Peter W. Bernhardt

OES Faculty Publications

Sea level rise has increased the frequency of tidal flooding even without accompanying precipitation in many coastal areas worldwide. As the tide rises, inundates the landscape, and then recedes, it can transport organic and inorganic matter between terrestrial systems and adjacent aquatic environments. However, the chemical and biological effects of tidal flooding on urban estuarine systems remain poorly constrained. Here, we provide the first extensive quantification of floodwater nutrient concentrations during a tidal flooding event and estimate the nitrogen (N) loading to the Lafayette River, an urban tidal sub-tributary of the lower Chesapeake Bay (USA). To enable the scale of …

An Assessment Of Regional Icesat-2 Sea-Level Trends, Brett Buzzanga, Eduard Heijkoop, Benjamin D. Hamlington, R. Steven Nerem, Alex Gardner

OES Faculty Publications

Sea-level rise is an important indicator of ongoing climate change and well observed by satellite altimetry. However, observations from conventional altimetry degrade at the coast where regional sea-level changes can deviate from the open-ocean and impact local communities. With the 2018 launch of the laser altimeter onboard ICESat-2, new high-resolution observations of ice, land, and ocean elevations are available. Here we assess the potential benefits of sea level measured by ICESat-2 by comparing to data from Jason-3 and tide gauges. We find good agreement in the linear rates computed from the independent observations, with an absolute average residual of 3.60 …

Seasonal Dispersal Of Fjord Meltwaters As An Important Source Of Iron And Manganese To Coastal Antarctic Phytoplankton, Kiefer O. Forsch, Lisa Hahn-Woernle, Robert M. Sherrell, Vincent J. Roccanova, Kaixuan Bu, David Burdige, Maria Vernet, Katherine A. Barbeau

OES Faculty Publications

Glacial meltwater from the western Antarctic Ice Sheet is hypothesized to be an important source of cryospheric iron, fertilizing the Southern Ocean, yet its trace-metal composition and factors that control its dispersal remain poorly constrained. Here we characterize meltwater iron sources in a heavily glaciated western Antarctic Peninsula (WAP) fjord. Using dissolved and particulate ratios of manganese to iron in meltwaters, porewaters, and seawater, we show that surface glacial melt and subglacial plumes contribute to the seasonal cycle of iron and manganese within a fjord still relatively unaffected by climate-change-induced glacial retreat. Organic ligands derived from the phytoplankton bloom and …

Central Equatorial Pacific Cooling During The Last Glacial Maximum, Minda Moriah Monteagudo, Jean Lynch-Stieglitz, Thomas M. Marchitto, Matthew W. Schmidt

OES Faculty Publications

Establishing tropical sea surface temperature (SST) during the Last Glacial Maximum (LGM) is important for constraining equilibrium climate sensitivity to radiative forcing. Until now, there has been little data from the central equatorial Pacific in global compilations, with foraminiferal assemblage‐based estimates suggesting the region was within 1°C of modern temperatures during the LGM. This is in stark contrast to multi‐proxy evidence from the eastern and western Pacific and model simulations which support larger cooling. Here we present the first estimates of glacial SST in the central equatorial Pacific from Mg/Ca in Globigerinoides ruber. Our results show that the central Pacific …

Diatom Hotspots Driven By Western Boundary Current Instability, Hilde Oliver, Weifeng G. Zhang, Walker O. Smith Jr., Philip Alatalo, P. Dreux Chappell, Andrew J. Hirzel, Corday R. Selden, Heidi M. Sosik, Rachel H.R. Stanley, Yifan Zhu, Dennis J. Mcgillicuddy Jr.

OES Faculty Publications

Abstract Climatic changes have decreased the stability of the Gulf Stream (GS), increasing the frequency at which its meanders interact with the Mid-Atlantic Bight (MAB) continental shelf and slope region. These intrusions are thought to suppress biological productivity by transporting low-nutrient water to the otherwise productive shelf edge region. Here we present evidence of widespread, anomalously intense subsurface diatom hotspots in the MAB slope sea that likely resulted from a GS intrusion in July 2019. The hotspots (at ∼50 m) were associated with water mass properties characteristic of GS water (∼100 m); it is probable that the hotspots resulted from …

A Kernel-Based Change Detection Method To Map Shifts In Phytoplankton Communities Measured By Flow Cytometry, Corinne Jones, Sophie Clayton, François Ribalet, E. Virginia Armbrust, Zaid Harchaoui

OES Faculty Publications

1. Automated, ship-board flow cytometers provide high-resolution maps of phytoplankton composition over large swaths of the world's oceans. They therefore pave the way for understanding how environmental conditions shape community structure. Identification of community changes along a cruise transect commonly segments the data into distinct regions. However, existing segmentation methods are generally not applicable to flow cytometry data, as these data are recorded as ‘point cloud’ data, with hundreds or thousands of particles measured during each time interval. Moreover, nonparametric segmentation methods that do not rely on prior knowledge of the number of species are desirable to map community shifts. …

Marine Phytoplankton Functional Types Exhibit Diverse Responses To Thermal Change, S. I. Anderson, A. D. Barton, Sophie Clayton, S. Dutkiewicz, T. A. Rynearson

OES Faculty Publications

Marine phytoplankton generate half of global primary production, making them essential to ecosystem functioning and biogeochemical cycling. Though phytoplankton are phylogenetically diverse, studies rarely designate unique thermal traits to different taxa, resulting in coarse representations of phytoplankton thermal responses. Here we assessed phytoplankton functional responses to temperature using empirically derived thermal growth rates from four principal contributors to marine productivity: diatoms, dinoflagellates, cyanobacteria, and coccolithophores. Using modeled sea surface temperatures for 1950-1970 and 2080-2100, we explored potential alterations to each group's growth rates and geographical distribution under a future climate change scenario. Contrary to the commonly applied Eppley formulation, our …

Life In Hampton Roads Survey Press Release #7: Perceptions Of Flooding, Hurricane Evacuation, & Sheltering During Covid-19, Social Science Research Center, Old Dominion University

Life in Hampton Roads Survey Report

Life in Hampton Roads 2021 - Flooding, Hurricane Evacuation, & Sheltering During COVID-19

The changing climate and rising sea levels touch nearly every aspect of life in Hampton Roads, with some neighborhoods and communities experiencing it more acutely. But, overall, how persistent is recurrent flooding as perceived by Hampton Roads residents? This year’s survey finds that nearly 23% of respondents state that recurrent flooding is a problem in their neighborhood, a number broadly consistent with the responses seen since this question was first asked in 2013 when 23% of respondents also indicated that recurrent flooding was a problem in their …

Evaluation Of A Low-Cost Uas And Phenocams For Measuring Grapevine Greenness, Timothy J. Hoheneder

Graduate Theses, Dissertations, and Problem Reports (ETD)

Unpersoned aerial systems (UAS) could provide winegrowers with the potential to monitor vineyard productivity with ultra-high-resolution imagery and low operational costs. This ability could prove particularly valuable in the challenging cool-climate viticultural areas of Appalachia. Especially in this mountainous region of increasingly variable microclimates, there could be of great value from an ability to use UAS-measured greenness to monitor wine grape phenology and predict harvest quality and quantity. In this study, I assess how UAS-measured greenness relates to three complementary measures of field-based: leaf angle measurements, phenocam measured greenness, and leaf spectral measurements of greenness. After correlating these field-based measures …

Anticipating And Adapting To The Future Impacts Of Climate Change On The Health, Security And Welfare Of Low Elevation Coastal Zone (Lecz) Communities In Southeastern Usa, Thomas Allen, Joshua Behr, Anamaria Bukvic, Ryan S.D. Calder, Kiki Caruson, Charles Connor, Christopher D'Elia, David Dismukes, Robin Ersing, Rima Franklin, Jesse Goldstein, Jonathon Goodall, Scott Hemmerling, Jennifer Irish, Steven Lazarus, Derek Loftis, Mark Luther, Leigh Mccallister, Karen Mcglathery, Molly Mitchell, William Moore, Charles Reid Nichols, Karinna Nunez, Matthew Reidenbach, Julie Shortridge, Robert Weisberg, Robert Weiss, Lynn Donelson Wright, Meng Xia, Kehui Xu, Donald Young, Gary Zarillo, Julie C. Zinnert

Political Science & Geography Faculty Publications

Low elevation coastal zones (LECZ) are extensive throughout the southeastern United States. LECZ communities are threatened by inundation from sea level rise, storm surge, wetland degradation, land subsidence, and hydrological flooding. Communication among scientists, stakeholders, policy makers and minority and poor residents must improve. We must predict processes spanning the ecological, physical, social, and health sciences. Communities need to address linkages of (1) human and socioeconomic vulnerabilities; (2) public health and safety; (3) economic concerns; (4) land loss; (5) wetland threats; and (6) coastal inundation. Essential capabilities must include a network to assemble and distribute data and model code to …

Inference Of Surface Velocities From Oblique Time Lapse Photos And Terrestrial Based Lidar At The Helheim Glacier, Franklyn T. Dunbar Ii

Graduate Student Theses, Dissertations, & Professional Papers

Using time dependent observations derived from terrestrial LiDAR and oblique
time-lapse imagery, we demonstrate that a Bayesian approach to glacial motion es-
timation provides a concise way to incorporate multiple data products into a single
motion estimation procedure effectively producing surface velocity estimates with
an associated uncertainty. This approach brings both improved computational effi-
ciency, and greater scalability across observational time-frames when compared to
existing methods. To gauge efficacy, we apply these methods to a set of observa-
tions from the Helheim Glacier, a critical actor in contemporary mass loss trends
observed in the Greenland Ice Sheet. We find that …

Predicting The Impacts Of Climate Change On The Great Lakes Water Levels Using A Fully Coupled 3d Regional Modeling System, Miraj Kayastha

Dissertations, Master's Theses and Master's Reports

The Great Lakes of North America are the largest surface freshwater system in the world and many ecosystems, industries, and coastal processes are sensitive to the changes in their water levels. The recent changes in the Great Lakes climate and water levels have particularly highlighted the importance of water level prediction. The water levels of the Great Lakes are primarily governed by the net basin supplies (NBS) of each lake which are the sum of over-lake precipitation and basin runoff minus lake evaporation. Recent studies have utilized Regional Climate Models (RCMs) with a fully coupled one-dimensional (1D) lake model to …

Wave Climate Associated With Changing Water Level And Ice Cover In Lake Michigan, Chenfu Huang, Longhuan Zhu, Gangfeng Ma, Guy A. Meadows, Pengfei Xue

Civil & Environmental Engineering Faculty Publications

Detailed knowledge of wave climate change is essential for understanding coastal geomorphological processes, ecosystem resilience, the design of offshore and coastal engineering structures and aquaculture systems. In Lake Michigan, the in-situ wave observations suitable for long-term analysis are limited to two offshore MetOcean buoys. Since this distribution is inadequate to fully represent spatial patterns of wave climate across the lake, a series of high-resolution SWAN model simulations were performed for the analysis of long-term wave climate change for the entirety of Lake Michigan from 1979 to 2020. Model results were validated against observations from two offshore buoys and 16 coastal …

Characterizing Seagrass Effects On Hydrodynamics Of Waves And Currents Through Field Measurements And Computational Modelling, Ramin Familkhalili, Navid Tahvildari

Civil & Environmental Engineering Faculty Publications

Low-lying coastal and estuarine areas are among the most populated regions globally, have high economic significance, and are increasingly threatened by climate change, sea level rise, nuisance flooding, and extreme storms. Nature-based coastal protections are sustainable and sea-level resilient alternatives compared to traditional solutions such as dikes and seawalls. Submerged aquatic vegetation (SAV) or seagrasses can provide coastal flood and erosion protection by attenuating storm wave and current energy and stabilizing seabed sediments. However, more research is needed to understand the interactions between flow, SAVs, and sediments. These dynamic interactions affect flow at different scales and seagrass productivity. In this …

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 …

2020 - Tennessee Annual Climate Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Monthly Reports

No abstract provided.