NSIDC IceBridge Value Added Data Products

1. NSIDC IceBridgeValue Added Data Products Ted Scambos, Bruce Raup, Susan Rogers, Mary-Jo Brodzik

2. IceBridge Value Added Data Products from NSIDC • NSIDC was asked to include production of value added, science-targeted products in its data management proposal. • We are working on two basic types of products: –updates to ice sheet gridded data sets, such as ice surface elevation and bed topography. –flightlinealong-track profile data sets, combining instrument data sets for specific studies. • These value-added products will be produced in conjunction with the Ice Bridge Science Team members, Instrument Team members, and the SWG • The first products we aredeveloping are multi-data-set DEM for Greenland, dH/dt for Greenland (w/B. Csatho), and two along-flight profile data sets: ice sheet ice dynamics andsurface properties

3. Gridded Product: Rapid Update of Greenland Multi-instrument DEM and dH/dt • B. Csatho and G. Babonis (SUNY Buffalo) have been developing dH/dt relationship for all ICESat-1 cross-over and ATM-ICESat cross-over points (6000 points). Elevations at the crossovers are fit to a 3rd-order polynomial. -this will be updated with each IceBridge campaign • B. Raup will create a merged Greenland DEM using Bamber DEM, ASTER photogrammetric elevation grids, and MODIS-derived photoclinometry of the Greenland interior (T. Haran). B. Raup will also develop a rapid re-gridding tool. • A time-corrected ‘best’ DEM will be produced, as well as a means of rapid updating of the DEM, by NSIDC/Csatho, e.g. an ice-sheet wide elevation grid referenced to 2005 (mid ICESat-1 –time) or 2011 (latest available). • Both the dH/dt grid and the merged corrected DEM will be distributed by NSIDC under IceBridge

4. Along-Track Products: Ice Sheet, Sea Ice, and Surface Properties Multi-instrument ‘Tables’ • We will combine groups of measurements from the instruments for science-topic specific applications. In assembling the data, we propose cross-checking, quality control and derived product generation. • Along-flight-track data format will be (eventually) ‘meta-tables’: Embedded links and images, etc. • Two NSIDC Along-Track Products at present: (all are based on the NASA P-3 or DC-8 platforms) – Ice Sheet Data Product Set: ATM Nadir Elevation and Slope, MCORDS Bed Elev, Ice Thickness, Bed Refl. Strength, radar traces, SANDER Free Air Gravity, DMS images, stereo DEM – Surface Properties Data Product Set: ATM Swath Elev, Slope, Roughness, Snow Radar, DMS images, stereo DEM, Surface Skin Temp – Sea Ice Data Product Set (Laura Koenig et al., NASA GSFC): ATM Elevation, RMS Roughness, Ku Radar, DMS images, Surface Skin Temp ( )

6. Gridded Product: Greenland Multi-instrument DEM and dH/dt

7. Gridded Product: Greenland Multi-instrument DEM and dH/dt Scambos DEM (upper left) +interpolated ICESat residual (lower left)= new DEM (right) NASA PARCA/Polar Research Meeting Pasedena, CA January 29-31, 2007

8. Gridded Products: Improvements to bedrock maps • Create similar system for updating gridded bed elevation data; • Mass continuity: surface topography (DEM) and ice flow speed (MEaSURES data) to infer topography • Use gravimeter data to extend/refine ice thickness measurements from radar;

9. Currently assembling the tables, assessing offsets, errors, quality parameters Along-Flight Track Data Set Ice Sheet Product Profile OIB 10.18.2009 Antarctica TSK1 Mission ATM Input A/C Orientation Gravity Input MCORDS Input

10. Along-Flight Track Data Set Ice Sheet Product Profile OIB 10.18.2009 Antarctica TSK1 Mission MCORDS Input, data source DMS Image link

11. The ATM data sample rate is 0.25 seconds and the GRAV data is 0.5 seconds. The Table requires that the minimum absolute value of the time error between ATM and Gravimeter data to be less than 0.25 seconds. The MCoRDS data does not have a static sample rate; it varies near 0.17 seconds. The Table requires that the minimum absolute value of the time error between ATM and MCoRDS data to be less than 0.17 seconds. LAT/LON TIME IGGRV1B & ILATM2 IRMCR2 & ILATM2

12. 200 km

13. Where to take the along-track data sets next? – Ice Sheet Data Product Set: ATM Nadir Elevation and Slope, MCORDS Ice Thickness, and Radar Traces, SANDER Free Air Gravity, DMS images, stereo DEM •Combine ATM/DMS slope (at ~2 km avg) and ice thickness and report local driving stress; •Combine MCORDS Ice Thickness and Gravity and report nominal near-surf. bedrock density; (or quality control MCORDS bedrock elevation/ice thickness pick) – Sea Ice Data Product Set: ATM FreeboardElev, Surface Roughness*, Ku Radar, DMS images, stereo DEM, Surface Skin Temp •Re-calculate Qfit (ATM) and/or DMS stereo DEM elevation statistics for ice type information; – Surface Properties Data Product Set: ATM Swath Elev, Slope, Roughness*, Snow Radar, DMS images, stereo DEM;Surface Skin Temperature •surface snow grain size (from DMS w/modifications); •combine gridded products (outside IceBridge), radar, others to infer accumulation rate.

14. NSIDC IceBridge Gridded Product Projection Selections: Arctic/Greenland Polar Stereographic 70°N plane of projection 135°E up, 45°W down WGS84 ellipsoid Antarctica Polar Stereographic 71°S plane of projection 0° up, 180°down WGS84 ellipsoid 100 m SAR Radarsat-1 mosaic (Kwok) MODIS Mosaic of Greenland (MOG, shown above) MEaSURESInSAR ice velocity data sets 1-km ICESat Greenland DEM (Zwally) 5km Radar Altimetry Greenland DEM (y=39°N) NSIDC Passive Microwave Data (Hughes ellip.) 25 m RAMP and MAMM Radarsat products (Jezek) MODIS Mosaic of Antarctica (MOA, shown above) MEaSURESInSAR ice velocity data sets 1-km ICESat+Radar Alt DEM (Bamber) AVHRR and LIMA mosaics (USGS, Bindschdlr) ICESat 500m DEM (70°S, Hughes Ellips.) NSIDC Passive Microwave Data (70°S, Hughes ellip.)