Optical, structural and kinematic characteristics of freshwater plumes under landfast sea ice during the spring freshet in the Alaskan coastal Arctic

• Published in: Journal of Geophysical Research: Oceans
• Main Authors: Okkonen, Stephen R., Laney, Samuel R.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: American Geophysical Union 2021
• Subjects: arctic; estuarine; carbon; optics; rivers; sea ice; Arctic; Stefansson; Stefansson Sound; Prudhoe Bay; Sea ice; Alaska
• Online Access: https://hdl.handle.net/1912/28076

Author Posting. © American Geophysical Union, 2021. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 126(12),(2021): e2021JC017549, https://doi.org/10.1029/2021JC017549. Rivers deliver freshwater and entrained terrestrial materials into the coastal ocean from adjacent continental landmasses. In the coastal Arctic, a large fraction of terrestrially sourced dissolved and particulate organic carbon (DOC and POC) is delivered by snowpack meltwaters of the spring freshet, when many coastal ocean regions remain covered by landfast ice. Here we report on an array of moored sensors and telemetering ice buoys deployed in advance of the 2018 spring freshet in Stefansson Sound near Prudhoe Bay, Alaska. This instrumented array monitored temporal and spatial variations in hydrographic properties before and during the freshet, as well as optical properties that serve as proxies for DOC and POC contained in the freshet plumes. The temporal evolution of these optical signals occurred in five stages, each associated with characteristic water column structural and kinematic characteristics. Spatial differences among fluorescent dissolved organic matter (FDOM) and optical backscatter (OBS) signals across the ice buoy array, evident later during the freshet, allowed identification of plume waters sourced from the Kuparuk, Sagavanirktok, and Shaviovik drainage basins. This work was funded by the National Aeronautics and Space Administration's Carbon Cycle and Ecosystems program (NNX17AI72G). This is contribution #11 from the Scholarly Union of Bio-Physical Arctic Researchers. 2022-05-25