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374 results on '"Wethey, David S."'

6. Validation and Application of Satellite-Derived Sea Surface Temperature Gradients in the Bering Strait and Bering Sea.

Author

Vazquez-Cuervo, Jorge, Steele, Michael, Wethey, David S., Gómez-Valdés, José, García-Reyes, Marisol, Spratt, Rachel, and Wang, Yang

Subjects
REMOTE sensing, SEA ice, MICROWAVE remote sensing, EXTREME weather, ROOT-mean-squares
Abstract

The Arctic is one of the most important regions in the world's oceans for understanding the impacts of a changing climate. Yet, it is also difficult to measure because of extreme weather and ice conditions. In this work, we directly compare four datasets from the Group for High-Resolution Sea Surface Temperature (GHRSST) with a NASA Saildrone deployment along the Alaskan Coast and the Bering Sea and Bering Strait. The four datasets used are the Remote Sensing Systems Microwave Infrared Optimally Interpolated (MWIR) product, the Canadian Meteorological Center (CMC) product, the Daily Optimally Interpolated Product (DOISST), and the Operational Sea Surface Temperature and Ice Analysis (OSTIA) product. Spatial sea surface temperature (SST) gradients were derived for both the Saildrone deployment and GHRSST products, with the GHRSST products collocated with the Saildrone deployment. Overall, statistics indicate that the OSTIA product had a correlation of 0.79 and a root mean square difference of 0.11 °C/km when compared with Saildrone. CMC had the highest correlation of 0.81. Scatter plots indicate that OSTIA had the slope closest to one, thus best reproducing the magnitudes of the Saildrone gradients. Differences increased at latitudes > 65°N where sea ice would have a greater impact. A trend analysis was then performed on the gradient fields. Overall, positive trends in gradients occurred in areas along the coastal regions. A negative trend occurred at approximately 60°N. A major finding of this study is that future work needs to revolve around the impact of changing ice conditions on SST gradients. Another major finding is that a northward shift in the southern ice edge occurred after 2010 with a maxima at approximately 2019. This indicates that the shift of the southern ice edge is not gradual but has dramatically increased over the last decade. Future work needs to revolve around examining the possible causes for this northward shift. [ABSTRACT FROM AUTHOR]

Published
2024
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19. The stress response of the seagrass Zostera noltei and three commercial clam species to low salinity associated with heavy rainfall.

Author

Román, Salvador, Vázquez, Elsa, Román, Marta, Viejo, Rosa M, Weidberg, Nicolás, Troncoso, Jesús S, Woodin, Sarah A, Wethey, David S, and Olabarria, Celia

Subjects
ZOSTERA, MANILA clam, SEAGRASSES, SALINITY, CLAMS, SHELLFISH, SPECIES
Abstract

The maintenance of stocks of estuarine species strongly depends on the ability of the species to cope with environmental stress. In NW Spain, commercial clam beds, which are usually co-occupied by the seagrass Zostera noltei , are often exposed to reduced salinity caused by intense rainfalls. Our goals were to evaluate the effects of low salinity events on both juvenile clams and Z. noltei , including their interactions. A mesocosm experiment was performed to simulate three salinity decreases (35–35, 25–10, and 20–5), and several indicators of clam and seagrass performance were measured after 3 and 6 days of exposure and again after a recovery period of 4 days. No differences were observed in the non-native clam Ruditapes philippinarum , while oxygen consumption, clearance rate and growth decreased significantly in the native clams R. decussatus and Venerupis corrugata in response to low salinity stress. Zostera noltei indicators did not vary in response to low salinity exposure, except the sucrose content, which decreased. Moreover, the seagrass buffered juvenile clams from salinity fluctuations in the short term, although the interactions were weak. The species-specific sensitivity to low salinity should be a major concern in future management plans for the shellfish beds in the context of climate change. [ABSTRACT FROM AUTHOR]

Published
2024
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21. Bioirrigation

Author

Volkenborn, Nils, primary, Woodin, Sarah A., additional, Wethey, David S., additional, and Polerecky, Lubos, additional

Published
2019
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27. Sea Surface Temperature Gradients Estimation Using Top-of-Atmosphere Observations from the ESA Earth Explorer 10 Harmony Mission: Preliminary Studies

Author

Ciani, Daniele (author), Sabatini, Mattia (author), Buongiorno Nardelli, Bruno (author), Lopez Dekker, F.J. (author), Rommen, Björn (author), Wethey, David S. (author), Yang, Chunxue (author), Liberti, Gian Luigi (author), Ciani, Daniele (author), Sabatini, Mattia (author), Buongiorno Nardelli, Bruno (author), Lopez Dekker, F.J. (author), Rommen, Björn (author), Wethey, David S. (author), Yang, Chunxue (author), and Liberti, Gian Luigi (author)

Abstract

The Harmony satellite mission was recently approved as the next European Space Agency (ESA) Earth Explorer 10. The mission science objectives cover several applications related to solid earth, the cryosphere, upper-ocean dynamics and air–sea interactions. The mission consists of a constellation of two satellites, flying with the Copernicus Sentinel 1 (C or D) spacecraft, each hosting a C-band receive-only radar and a thermal infrared (TIR) payload. From an ocean dynamics/air–sea interaction perspective, the mission will provide the unique opportunity to observe simultaneously the signature of submesoscale upper-ocean processes via synthetic aperture radar and TIR imagery. The TIR imager is based on microbolometer technology and its acquisitions will rely on four channels: three narrow-band channels yielding observations at a ≃1 km spatial sampling distance (SSD) and a panchromatic (PAN, 8–12 (Formula presented.) m) channel characterized by a ≃300 m SSD. Our study investigates the potential of Harmony in retrieving spatial features related to sea surface temperature (SST) gradients from the high-resolution PAN channel, relying on top-of-atmosphere (TOA) observations. Compared to a standard SST gradient retrieval, our approach does not require atmospheric correction, thus avoiding uncertainties due to inter-channel co-registration and radiometric consistency, with the possibility of exploiting the higher resolution of the PAN channel. The investigations were carried out simulating the future Harmony TOA radiances (TARs), as well as relying on existing state-of-the-art level 1 satellite products. Our approach enables the correct description of SST features at the sea surface avoiding the generation of spurious features due to atmospheric correction and/or instrumental issues. In addition, analyses based on existing satellite products suggest that the clear-sky TOA observations, in a typical mid-latitude scene, allow the reconstruction of up to 85% of the gradient ma, Mathematical Geodesy and Positioning

Published
2023
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41. Impacts of sublethal and lethal high temperatures on clams exploited in European fisheries

Author

Macho, Gonzalo, Woodin, Sarah A., Wethey, David S., and Vazquez, Elsa

Subjects
Clams -- Environmental aspects -- Health aspects, Atmospheric temperature -- Environmental aspects -- Health aspects, Biological sciences, Zoology and wildlife conservation
Abstract

ABSTRACT In Galicia, three venerid bivalves are exploited in the intertidal zone by local fishery guilds: Venerupis corrugata, Ruditapes philippinarum, and Rudilapes decussatus. The precise effects of the duration and [...]

Published
2016
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