Posters

Poster Session 2, Tuesday,  October  4, 10:40–12:40

Poster 70

Mackenzie River Discharge and Effects on Arctic Sea Ice, Biological, and Biogeochemical Processes in the Littoral Zone of the Beaufort Sea in the Arctic Ocean

River discharge into the Arctic Ocean increased since the 1960s with a mean annual discharge from 72 rivers totaling >2.5 trillion m 3 . Using satellite data from optical/multispectral sensors on MODIS and Sentinel-2 and radars on Sentinel-1A/1B, together with aircraft observations (e.g., ALAR) and ocean buoys (e.g., IABP, SPOT, LIMB), we examine effects of river discharge from the Mackenzie River into the coastal Beaufort Sea. Sea ice mapping shows that ice breakup recurs along the 25-m isobath in multiple years. After breakup, the relatively warm and fresh river waters rise on the surface and contribute to reduce the sea ice cover in the Mackenzie littoral zone. This increases the surface temperature while releasing chlorophyll-a and particulate organic carbon hundreds of km into the Beaufort Sea. Moreover, vapor plumes and sea spray aerosols from open leads and polynyas affect both the dynamics and composition in the atmospheric boundary layer, including cloud cover. Thus, pollutants (e.g., mercury, a bioaccumulative neurotoxin) can be from both air and river sources. With daily satellite microwave radiometer data (e.g., AMSR, GPM, SMAP), we monitor river flows and the timing of river ice break-up along the river length that is important to estimate the duration when the river water can absorb continental heat and load materials from runoff. A similar methodology can be applied to the Yukon River that discharges into the Bering Sea. These approaches will advance our understanding of interactions involving riverine, sea ice, biological, biogeochemical, and boundary layer chemical and physical processes in the Arctic.

Son Nghiem, NASA Jet Propulsion Laboratory, California Institute of Technology, [email protected], 0000-0002-4592-2979 

G. Robert Brakenridge, Institute of Arctic and Alpine Research, University of Colorado, Boulder, Colorado, USA, [email protected] 

Thomas Douglas, US Army Cold Regions Research & Engineering Laboratory, Fort Wainwright, Alaska, USA, [email protected] 

Dorothy Hall, Earth System Science Interdisciplinary Center, University of Maryland, College Park, Maryland, USA, [email protected]

Zsofia Kugler, Department of Photogrammetry and Geoinformatics, Budapest University of Technology and Economics, Budapest, Hungary, [email protected] 

Patricia Matrai, Air-Sea Exchange Laboratory, Bigelow Laboratory for Ocean Sciences, East Boothbay, Maine, USA, [email protected] 

Daniel Obrist, Department of Environmental, Earth and Atmospheric Sciences, University of Massachusetts, Lowell, Massachusetts, USA, [email protected] 

Donald Perovich, Dartmouth Engineering, Thayer School, Dartmouth College, Hanover, New Hampshire, USA, [email protected] 

Ignatius Rigor, Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, Washington, USA, [email protected] 

Paul Shepson, School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, New York, USA, [email protected] 

Alexandra Steffen, Air Quality Research Division, Science and Technology Branch, Environment and Climate Change Canada, Toronto, Canada, [email protected]