Radiometers operating at L-band (1.4 GHz) are used to retrieve sea surface salinity over ice-free oceans and have been used recently to study the cryosphere. One hindrance of their use in the high latitudes is the preponderance of mixed scenes, where seawater and sea ice are both present in the sensor's field of view (FOV). Accurately characterizing the scene is crucial for oceanographic and cryospheric applications. To that end, a sea ice fraction model, composed of passive microwave sea ice concentration retrievals and an instrument simulator that integrates radiative power coming from all around the antenna, is used. We investigate the model currently used operationally to derive the ice fraction affecting the Aquarius observations and show that it can be significantly improved. On the one hand, the current model tends to overestimate sea ice fraction in the marginal ice zone where observations are used for salinity retrievals. On the other hand, the current model underestimates ice fraction within the ice pack where observations are used to derive sea ice properties. For the northern hemisphere, we also find evidence of the sea ice type impact on L-band radiometric observations. We present a model to derive sea ice fractions that are in better agreement with Aquarius radiometric observations using the Advanced Microwave Scanning Radiometer 2 Bootstrap algorithm for sea ice concentration and using high-resolution integration over the sensor's FOV.
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http://dx.doi.org/10.1109/TGRS.2016.2622011 | DOI Listing |
Sci Total Environ
December 2024
Ministry of Natural Resources Key Laboratory for Polar Sciences, Polar Research Institute of China, NO.451, Jinqiao Road, Shanghai, 200136, China; Zhejiang University of Water Resources and Electric Power, NO. 508, Second Avenue, Hangzhou, Zhejiang, 310018, China. Electronic address:
We investigate the spatial distribution and potential ecological impact of Currently Used Organophosphorus Pollutants (CUOPPs) in the Arctic Ocean, focusing on the East Siberian Sea, Laptev Sea, and high Arctic regions. Analyzing surface water samples collected during a scientific expedition aboard the "Xuelong 2" in August and September 2021, we detected 38 out of 83 targeted CUOPPs, including Phorate, Paraoxon, and Azinphos-ethyl, with concentrations exhibiting significant geographical variance. The results reveal a pronounced increase in CUOPP concentrations towards the Arctic poles, diverging markedly from the patterns observed in the East China Sea, thereby highlighting distinct regional pollution profiles and environmental interactions.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Cooperative Institute for Climate, Ocean, and Ecosystem Studies, University of Washington, Seattle, WA 98105.
The Atlantic Meridional Overturning Circulation (AMOC) is a key component of the global climate that is projected to weaken under future anthropogenic climate change. While many studies have investigated the AMOC's response to different levels and types of forcing in climate models, relatively little attention has been paid to the AMOC's sensitivity to the rate of forcing change, despite it also being highly uncertain in future emissions scenarios. In this study, I isolate the AMOC's response to different rates of CO increase in a state-of-the-art global climate model and find that the AMOC undergoes more severe weakening under faster rates of CO change, even when the magnitude of CO change is the same.
View Article and Find Full Text PDFPolar Biol
December 2024
Department of Geography, Durham University, South Road, Durham, DH1 3LE UK.
Knowledge of the spatial distribution of many polar seabird species is incomplete due to the remoteness of their breeding locations. Here, we compiled a new database of published and unpublished records of all known snow petrel breeding sites. We quantified local environmental conditions at sites by appending indices of climate and substrate, and regional-scale conditions by appending 30 year mean (1992-2021) sea-ice conditions within accessible foraging areas.
View Article and Find Full Text PDFSci Data
December 2024
University of Oslo, Department of Geosciences, Oslo, 0313, Norway.
Sea ice is a key element of the global Earth system, with a major impact on global climate and regional weather. Unfortunately, accurate sea ice modeling is challenging due to the diversity and complexity of underlying physics happening there, and a relative lack of ground truth observations. This is especially true for the Marginal Ice Zone (MIZ), which is the area where sea ice is affected by incoming ocean waves.
View Article and Find Full Text PDFSci Data
December 2024
Center for Coastal and Ocean Mapping, University of New Hampshire, Durham, NH, USA.
Knowledge about seafloor depth, or bathymetry, is crucial for various marine activities, including scientific research, offshore industry, safety of navigation, and ocean exploration. Mapping the central Arctic Ocean is challenging due to the presence of perennial sea ice, which limits data collection to icebreakers, submarines, and drifting ice stations. The International Bathymetric Chart of the Arctic Ocean (IBCAO) was initiated in 1997 with the goal of updating the Arctic Ocean bathymetric portrayal.
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