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Full-Text Articles in Physical Sciences and Mathematics

Atmospheric Input And Seasonal Inventory Of Dissolved Iron In The Sargasso Sea: Implications For Iron Dynamics In Surface Waters Of The Subtropical Ocean, Peter N. Sedwick, Bettina M. Sohst, K. N. Buck, S. Caprara, R. J. Johnson, D. C. Ohnemus, L. E. Sofen, A. Tagliabue, B. S. Twining, Tara E. Williams Jan 2023

Atmospheric Input And Seasonal Inventory Of Dissolved Iron In The Sargasso Sea: Implications For Iron Dynamics In Surface Waters Of The Subtropical Ocean, Peter N. Sedwick, Bettina M. Sohst, K. N. Buck, S. Caprara, R. J. Johnson, D. C. Ohnemus, L. E. Sofen, A. Tagliabue, B. S. Twining, Tara E. Williams

OES Faculty Publications

Constraining the role of dust deposition in regulating the concentration of the essential micronutrient iron in surface ocean waters requires knowledge of the flux of seawater-soluble iron in aerosols and the replacement time of dissolved iron (DFe) in the euphotic zone. Here we estimate these quantities using seasonally resolved DFe data from the Bermuda Atlantic Time-series Study region and weekly-scale measurements of iron in aerosols and rain from Bermuda during 2019. In response to seasonal changes in vertical mixing, primary production and dust deposition, surface DFe concentrations vary from ∼0.2 nM in early spring to >1 nM in late summer, …


Assessing Phytoplankton Nutritional Status And Potential Impact Of Wet Deposition In Seasonally Oligotrophic Waters Of The Mid-Atlantic Bight, P. N. Sedwick, P. W. Bernhardt, M. R. Mulholland, R. G. Najjar, L. M. Blumen, B. M. Sohst, C. Sookhdeo, Brittany Widner Apr 2018

Assessing Phytoplankton Nutritional Status And Potential Impact Of Wet Deposition In Seasonally Oligotrophic Waters Of The Mid-Atlantic Bight, P. N. Sedwick, P. W. Bernhardt, M. R. Mulholland, R. G. Najjar, L. M. Blumen, B. M. Sohst, C. Sookhdeo, Brittany Widner

OES Faculty Publications

To assess phytoplankton nutritional status in seasonally oligotrophic waters of the southern Mid-Atlantic Bight, and the potential for rain to stimulate primary production in this region during summer, shipboard bioassay experiments were performed using natural seawater and phytoplankton collected north and south of the Gulf Stream. Bioassay treatments comprised iron, nitrate, iron + nitrate, iron + nitrate + phosphate, and rainwater. Phytoplankton growth was inferred from changes in chlorophyll a, inorganic nitrogen, and carbon-13 uptake, relative to unamended control treatments. Results indicated the greatest growth stimulation by iron + nitrate + phosphate, intermediate growth stimulation by rainwater, modest growth …


Wet And Dry Atmospheric Deposition Of Nutrients And Bioactive Trace Metals To Coastal Waters Of The Mid-Atlantic Bight, Christine Sookhdeo Jan 2018

Wet And Dry Atmospheric Deposition Of Nutrients And Bioactive Trace Metals To Coastal Waters Of The Mid-Atlantic Bight, Christine Sookhdeo

OES Theses and Dissertations

Atmospheric deposition provides a significant source of nutrients and bioactive trace metals to the surface ocean, including the seasonally oligotrophic waters of the Mid-Atlantic Bight. These atmospherically derived nutrients and trace metals enter the surface ocean via dry deposition of aerosols and wet deposition in rain. To estimate the aeolian input of nutrients and trace metals to coastal waters east of the Delmarva Peninsula, wet and dry atmospheric deposition samples were collected over a one-year time series at the Anheuser-Busch Coastal Research Center, Oyster, Virginia. Weekly composite samples were collected from May 2014 through June 2015. Nutrient species examined were …


Nitrous Oxide In The Atmosphere: First Measurements Of A Lower Thermospheric Source, Patrick E. Sheese, Kaley A. Walker, Chris D. Boone, Peter F. Bernath, Bernd Funke Mar 2016

Nitrous Oxide In The Atmosphere: First Measurements Of A Lower Thermospheric Source, Patrick E. Sheese, Kaley A. Walker, Chris D. Boone, Peter F. Bernath, Bernd Funke

Chemistry & Biochemistry Faculty Publications

Nitrous oxide (N2O) is an important anthropogenic greenhouse gas, as well as one of the most significant anthropogenic ozone-depleting substances in the stratosphere. The satellite-based instrument Atmospheric Chemistry Experiment-Fourier Transform Spectrometer has been observing the Earth's limb since 2004 and derives profiles of N2O volume mixing ratios in the upper troposphere to the lower thermosphere. The resulting climatology shows that N2O is continuously produced in the lower thermosphere via energetic particle precipitation and enhanced N2O is present at all latitudes, during all seasons. The results are consistent with an N2O …


Fossil And Contemporary Aerosol Particulate Organic Carbon In The Eastern United States: Implications For Deposition And Inputs To Watersheds, Andrew S. Wozniak, James E. Bauer, Rebecca M. Dickhut Jan 2011

Fossil And Contemporary Aerosol Particulate Organic Carbon In The Eastern United States: Implications For Deposition And Inputs To Watersheds, Andrew S. Wozniak, James E. Bauer, Rebecca M. Dickhut

Chemistry & Biochemistry Faculty Publications

Atmospheric particulate matter samples were collected from mid-Atlantic and northeastern U. S. (Virginia and New York, respectively) sites to assess the fossil versus contemporary sources contributing to aerosol organic carbon (OC) and the implications for its deposition to watersheds. Mean particulate matter total OC (TOC) deposition rates (wet + dry deposition) were calculated to be 1.6 and 2.4 mg C m-2 d-1 for the Virginia and New York sites, respectively. Wet deposition of particulate TOC was determined to be the dominant depositional mode, accounting for >65% (Virginia) and >80% (New York) of total aerosol TOC deposition. Isotopic mass …