Multi-Year Elevation Changes Near the West Margin of the Greenland Ice Sheet from Satellite Radar Altimetry

• Main Authors: Lingle, Craig S., Brenner, Anita C., Zwally, H. J., DiMarzio, John P.
• Other Authors: ALASKA UNIV FAIRBANKS GEOPHYSICAL INST
• Format: Text
• Language: English
• Published: 1992
• Subjects: Snow; Ice and Permafrost; Cartography and Aerial Photography; Meteorology; *ELEVATION; *HEIGHT FINDING; *ICE; *SATELLITE PHOTOGRAPHY; GREENLAND; HEIGHT; MEAN; MEASUREMENT; OCEAN SURFACE; ORBITS; SURFACES; RADAR; GREENHOUSE EFFECT; ENVIRONMENTAL IMPACT; *Global climate change; Component Reports; *Greenland ice sheet; Geosat exact repeat mission; Satellite radar altimetry; Greenland; Ice; Ice Sheet; permafrost
• Online Access: http://www.dtic.mil/docs/citations/ADP007265; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADP007265

Mean changes in the surface elevation near the west margin of the Greenland ice sheet are measured using Seasat altimetry and altimetry from the Geosat Exact Repeat Mission (ERM). The Seasat data extend from early July through early October 1978. The ERM data extend from winter 1986-87 through fall 1988. Both seasonal and multi-year changes are measured using altimetry referenced to GEM T2 orbits. The possible effects of orbit error are minimized by adjusting the orbits into a common ocean surface. Seasonal mean changes in the surface height are recognizable during the Geosat ERM. The multi-year measurements indicate the surface was lower by 0.4 +/- 0.4 m on average in late summer 1987 than in late summer 1978. The surface was lower by 0.2 +/- 0.5 m on average in late summer 1988 than in late summer 1978. As a control case, the computations are also carried out using altimetry referenced to orbits not adjusted into a common ocean surface.