Hydrologic controls on coastal suspended sediment plumes around the Greenland Ice Sheet
- 1Department of Geography, University of California, Los Angeles, 1255 Bunche Hall, 951524, Los Angeles, CA 90095, USA
- 2Department of Geography, Rutgers, The State University of New Jersey, 54 Joyce Kilmer Avenue, Piscataway, New Jersey 08854, USA
- 3Department of Geography, University of Utah, 260 S. Central Campus Dr., Salt Lake City, UT 84112, USA
- 4Department of Geography, The Ohio State University, 1036 Derby Hall, 154 North Oval Mall, Columbus, OH 43210, USA
- 5Byrd Polar Research Center, The Ohio State University, 1090 Carmack Rd., Columbus, OH 43210, USA
Abstract. Rising sea levels and increased surface melting of the Greenland ice sheet have heightened the need for direct observations of meltwater release from the ice edge to ocean. Buoyant sediment plumes that develop in fjords downstream of outlet glaciers are controlled by numerous factors, including meltwater runoff. Here, Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery is used to average surface suspended sediment concentration (SSC) in fjords around ∼80% of Greenland from 2000–2009. Spatial and temporal patterns in SSC are compared with positive-degree-days (PDD), a proxy for surface melting, from the Polar MM5 regional climate model. Over this decade significant geographic covariance occurred between ice sheet PDD and fjord SSC, with outlet type (land- vs. marine-terminating glaciers) also important. In general, high SSC is associated with high PDD and/or a high proportion of land-terminating glaciers. Unlike previous site-specific studies of the Watson River plume at Kangerlussuaq, temporal covariance is low, suggesting that plume dimensions best capture interannual runoff dynamics whereas SSC allows assessment of meltwater signals across much broader fjord environments around the ice sheet. Remote sensing of both plume characteristics thus offers a viable approach for observing spatial and temporal patterns of meltwater release from the Greenland ice sheet to the global ocean.