Meeting:Abstract 2011 CSDMS meeting-068

From CSDMS


Browse  abstracts

CSDMS all hands meeting 2011

Combining MODIS imagery and PLUME modeling to estimate discharge of freshwater from the Greenland Ice Sheet to the coast

Ben Hudson, CSDMS Boulder Colorado, . Benjamin.Hudson@colorado.edu
Irina Overeem, CSDMS - INSTAAR, Univ. of Colorado Boulder Colorado, United States. irina.overeem@colorado.edu
Daniel McGrath, Cires, Univ. of Colorado Boulder Colorado, United States.
James Syvitski, CSDMS - INSTAAR, Univ. of Colorado Boulder Colorado, United States. james.syvitski@colorado.edu


[[Image:|300px|right|link=File:]]Very few in-situ measurements of runoff from the Greenland Ice Sheet (GrIS) exist, though melt water runoff from the GrIS is important to global eustatic sea level, ocean salinity, thermohaline circulation and sea ice dynamics and the transport of sediment and nutrients to fjords and the ocean. We continue to develop the use of NASA MODIS imagery to gauge river discharge of sediment and freshwater into fjords hydrologically linked to the GrIS.

Essential to this remote sensing proxy are accurate models of fjord and plume dynamics. We compare Hutton and Syvitski’s PLUME model results to in situ oceanographic and sedimentological measurements of Greenlandic river sediment/freshwater plumes towards the end goal of exploring the suitability of inverting the PLUME model and combining it with remotely sensed MODIS imagery to estimate river discharge.

Within our study fjords a range of estuarine conditions present a robust test for our plume method, and in turn conditions present a range of complexities to test the suitability of inverting the PLUME model. Fjord conditions range from ocean to river dominated. Some plumes mix very quickly from fresh to near full ocean salinities (22 – 28 PSU). Other plumes maintain low salinities (0 – 10 PSU) to depths exceeding six meters and down fjord over 65 km. Fjord geometries, tidal range, and other conditions impact sediment plume dynamics. These dynamics must be accounted for to link plume imagery to discharge into fjords.