Yvon-Lewis Shari

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Last Name
Yvon-Lewis
First Name
Shari
ORCID
0000-0003-1378-8434

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Now showing 1 - 3 of 3
  • Article
    A comprehensive estimate for loss of atmospheric carbon tetrachloride (CCl4) to the ocean
    (Copernicus Publications on behalf of the European Geosciences Union, 2016-09-01) Butler, James H. ; Yvon-Lewis, Shari ; Lobert, Jurgen M. ; King, Daniel B. ; Montzka, Stephen ; Bullister, John L. ; Koropalov, Valentin ; Elkins, James W. ; Hall, Bradley D. ; Hu, Lei ; Liu, Yina
    Extensive undersaturations of carbon tetrachloride (CCl4) in Pacific, Atlantic, and Southern Ocean surface waters indicate that atmospheric CCl4 is consumed in large amounts by the ocean. Observations made on 16 research cruises between 1987 and 2010, ranging in latitude from 60° N to 77° S, show that negative saturations extend over most of the surface ocean. Corrected for physical effects associated with radiative heat flux, mixing, and air injection, these anomalies were commonly on the order of −5 to −10 %, with no clear relationship to temperature, productivity, or other gross surface water characteristics other than being more negative in association with upwelling. The atmospheric flux required to sustain these undersaturations is 12.4 (9.4–15.4) Gg yr−1, a loss rate implying a partial atmospheric lifetime with respect to the oceanic loss of 183 (147–241) yr and that  ∼  18 (14–22)  % of atmospheric CCl4 is lost to the ocean. Although CCl4 hydrolyzes in seawater, published hydrolysis rates for this gas are too slow to support such large undersaturations, given our current understanding of air–sea gas exchange rates. The even larger undersaturations in intermediate depth waters associated with reduced oxygen levels, observed in this study and by other investigators, strongly suggest that CCl4 is ubiquitously consumed at mid-depth, presumably by microbiota. Although this subsurface sink creates a gradient that drives a downward flux of CCl4, the gradient alone is not sufficient to explain the observed surface undersaturations. Since known chemical losses are likewise insufficient to sustain the observed undersaturations, this suggests a possible biological sink for CCl4 in surface or near-surface waters of the ocean. The total atmospheric lifetime for CCl4, based on these results and the most recent studies of soil uptake and loss in the stratosphere is now 32 (26–43) yr.
  • Dataset
    Carbonate chemistry, nutrient concentration, and dissolved oxygen concentration for discreet water samples collected during multiple cruises between June 2017 to Sept 2018 within Galveston Bay, TX
    (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2022-10-04) Shamberger, Kathryn E.F. ; Hicks, Tacey L. ; Fitzsimmons, Jessica N. ; Yvon-Lewis, Shari ; DiMarco, Steven
    These data include carbonate chemistry, nutrient concentration, and dissolved oxygen concentration for discreet water samples collected within Galveston Bay, TX. Eight single day cruises were conducted quarterly aboard the R/V Lithos or R/V Trident from June 2017 through September 2018. In addition, discreet water samples were collected at sites 10 - 60 km outside the mouth of the bay and up to 15m deep to characterize incoming seawater to the bay. These samples were collected on three cruises (WTX1 - R/V Manta, WTX3 - R/V Manta, WTX4 - R/V Pelican) in June, August, and November 2017. Discreet water samples were collected for total alkalinity and dissolved inorganic carbon, dissolved oxygen, and dissolved nutrients. CTD profiles were collected at each sampling site. Stochastic coastal acidification events in response to high volume rainfall and runoff that often accompanies tropical cyclone events has the potential to represent a significant threat to valuable calcifying reef ecosystems. Understanding acidification response and recovery to such events is critical to improving conservation and protection of coastal ecosystems, like oyster and coral reefs, particularly as climate change continues and tropical cyclone rainfall intensity increases. These data assess the impact of the rainfall and runoff from Hurricane Harvey on the acidification levels in Galveston Bay, TX. Samples were collected and analyzed primarily by Tacey Hicks, with assistance from other students in Dr. Katie Shamberger ’s research group, at Texas A&M University. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/881549
  • Dataset
    Carbonate chemistry, nutrient concentration, and dissolved oxygen concentration for discreet water samples collected during multiple cruises between June 2017 to Sept 2018 within Galveston Bay, TX
    (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2022-10-04) Shamberger, Kathryn E.F. ; Fitzsimmons, Jessica N. ; Yvon-Lewis, Shari ; DiMarco, Steven
    These data include carbonate chemistry, nutrient concentration, and dissolved oxygen concentration for discreet water samples collected within Galveston Bay, TX. Eight single day cruises were conducted quarterly aboard the R/V Lithos or R/V Trident from June 2017 through September 2018. In addition, discreet water samples were collected at sites 10 - 60 km outside the mouth of the bay and up to 15m deep to characterize incoming seawater to the bay. These samples were collected on three cruises (WTX1 - R/V Manta, WTX3 - R/V Manta, WTX4 - R/V Pelican) in June, August, and November 2017. Discreet water samples were collected for total alkalinity and dissolved inorganic carbon, dissolved oxygen, and dissolved nutrients. CTD profiles were collected at each sampling site. Stochastic coastal acidification events in response to high volume rainfall and runoff that often accompanies tropical cyclone events has the potential to represent a significant threat to valuable calcifying reef ecosystems. Understanding acidification response and recovery to such events is critical to improving conservation and protection of coastal ecosystems, like oyster and coral reefs, particularly as climate change continues and tropical cyclone rainfall intensity increases. These data assess the impact of the rainfall and runoff from Hurricane Harvey on the acidification levels in Galveston Bay, TX. Samples were collected and analyzed primarily by Tacey Hicks, with assistance from other students in Dr. Katie Shamberger ’s research group, at Texas A&M University. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/881549