WE PROPOSE TO EXTEND AND SUBSTANTIALLY IMPROVE THE COMPREHENSIVE RECORD OF THICKNESS VELOCITY AND ICE DISCHARGE FOR GREENLAND S MARINE-TERMINATING OUTLET GLACIERS IN ORDER TO CONSTRAIN ICE SHEET AND OCEAN MODELS AND BETTER UNDERSTAND CHANGES IN ICE DYNAMICS FRESHWATER FLUX MASS BALANCE AND CONTRIBUTION TO SEA LEVEL RISE. PREDICTIONS OF THE FUTURE BEHAVIOR OF GREENLAND S FAST-FLOWING OUTLET GLACIERS REMAIN HIGHLY UNCERTAIN DUE TO THEIR COMPLEX AND VARIABLE DYNAMICS. EXISTING ICE-SHEET WIDE RECORDS OF GLACIER VELOCITY DISCHARGE AND FRESHWATER FLUX COVER TOO SHORT A PERIOD AND ARE TOO COARSE IN TEMPORAL RESOLUTION TO PROVIDE ADEQUATE CONSTRAINTS FOR NUMERICAL ICE SHEET MODELS AND EFFORTS TO QUANTIFY FRESHWATER FORCING ON OCEAN CIRCULATION. RECENT EXPANSIONS IN OBSERVATIONAL CAPACITY FROM AIR AND SPACE NEW DATA ACCESS IMPROVED DATA PROCESSING METHODS AND ENHANCED SURFACE MASS BALANCE MODELING NOW ENABLE BACKWARD EXPANSION OF THESE RECORDS TO MID 1980 S WITH SEASONAL TO DAILY TEMPORAL RESOLUTION. WE WILL MERGE OBSERVATIONS FROM A WIDE RANGE OF EARTH OBSERVING SENSORS UTILIZING NASA PRODUCTS FROM THE MEASURES GREENLAND ICE MAPPING PROJECT AND OPERATION ICEBRIDGE AS WELL AS SUB-METER RESOLUTION IMAGERY FROM DIGITALGLOBE. THE LATTER OFFERS THE TRANSFORMATIVE POTENTIAL TO BRIDGE THE MEASUREMENT GAP BETWEEN GROUND OBSERVATIONS AND REMOTE SENSING BY ENABLING ~DAILY RESOLUTION ICE VELOCITY OBSERVATIONS OVER LARGE AREAS. WE WILL ALSO UTILIZE HIGH RESOLUTION REANALYSIS MODEL ESTIMATES OF SURFACE MASS BALANCE AND MELT RUNOFF TO DETERMINE GLACIER/ FJORD SCALE FRESHWATER FLUXES. WE WILL USE OUR IMPROVED RECORD TO ASSESS VARIABILITY IN ICE DYNAMICS DISCHARGE AND FRESHWATER FLUX AT A RANGE OF TIMESCALES FROM SHORT-TERM CHANGES DUE TO ICEBERG CALVING AND SEA ICE CONDITIONS TO MULTI-DECADAL SHIFTS DUE TO LONG-TERM CLIMATE AND OCEAN TRENDS. OUR PROJECT INCLUDES COLLABORATORS WHO WILL USE THESE OBSERVATIONS TO CONSTRAIN NUMERICAL ICE SHEET MODELS AND QUANTIFY FRESHWATER FORCING ON OCEAN CIRCULATION OFFERING IMMEDIATE AND WIDE-RANGING SCIENCE RETURN. OUR PROPOSAL RESPONDS TO SEVERAL OF THE OBJECTIVES OF THE NRA INCLUDING TO DETERMINE THE MECHANISMS CONTROLLING MASS BALANCE AND DYNAMICS OF THE GREENLAND ADVANCE UNDERSTANDING OF LAND-ICE PROCESSES ESPECIALLY CONNECTIONS AMONG THE WARMING OCEAN AND INCREASES IN GLACIAL FLOW RATES CHARACTERIZE LAND ICE PROPERTIES... AND PHYSICAL PROCESSES SUCH THAT THEY CAN BE INCORPORATED INTO MODELS AND USE REMOTE SENSING DATA TO VALIDATE AND IMPROVE MODELS OF LAND-BASED ICE AND THEIR CONTRIBUTIONS TO SEA-LEVEL CHANGE . OUR OBSERVATIONS WILL CROSS-VALIDATE AND IMPROVE MEASUREMENTS OBTAINED FROM THE NASA GRACE AND UPCOMING ICESAT-2 MISSIONS.
$378,838FY2020National Aeronautics and Space AdministrationNASA
Ohio State University, The, Columbus OH