Interpretation of short-term ice-sheet elevation changes inferred from satellite altimetry

摘要: Satellite altimetry offers means of directly measuring changes in surface elevation over the polar ice sheets Greenland and Antarctica. By relating these to variations mass, it becomes possible detect short-term Earth's sheets. However, is not immediately obvious that are indicative any (long-term) trend mass. An increase thickness may very well reflect response glacier random fluctuations precipitation. The spectrum this dominated by low frequencies, with majority variance contained longer time scales. As a result, ice-thickness record exhibit trends have no climatic significance, but due low-frequency forcing. A simple model for interpretation observed developed applied measurements made Ice Sheet. It appears be unlikely difference between rate thickening derived Zwally others (1989) using repeat satellite altimetry, significantly smaller previous estimates, can explained as being sheet forcing or attributed recent accumulation rate.