Summary
Meteorological nd glaciological analyses are integrated to examine the precipitation trends during the last three decades over the ice sheets covering Antarctica nd Greenland. For Antarctica, the best data source is provided by glaciologically-measured trends of snow accumulation, and for limited se...
| Main Authors: | , |
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| Other Authors: | |
| Format: | Text |
| Language: | English |
| Published: |
1993
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| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.668.7461 http://polarmet.osu.edu/PMG_publications/bromwich_robasky_map_1993.pdf |
| Summary: | Meteorological nd glaciological analyses are integrated to examine the precipitation trends during the last three decades over the ice sheets covering Antarctica nd Greenland. For Antarctica, the best data source is provided by glaciologically-measured trends of snow accumulation, and for limited sectors of East Antarctica consistency with precipitation amounts calculated from the atmospheric water balance quation is obtained. For Greenland, precipitation rates parameterized from atmospheric analyses yield the only comprehensive depiction. The precipitation rate over Antarctica ppears to have increased by about 5 % over a time period spanning the accumulation means for the 1955-65 to 1965-75 periods, while over Greenland it has decreased by about 15 % since 1963 with a secondary increase over the southern part of the ice sheet starting in 1977. At the end of the 10-year overlapping period, the global sea-level impact of the precipitation changes over Antarctica dominates that for Greenland and yields a net ice-sheet precipitation contribution of roughly-0.2mmyr-~. These changes are likely due to marked variations in the cyclonic forcing affecting the ice sheets, but are only weakly reflected in the temperature r gime, con-sistent with the episodic nature of cyclonic precipitation. These conclusions are not founded on high quality data bases. The importance of such changes for understanding global sea-level variations argues for a modest research effort to collect simultaneous meteorological nd glaciological observations in order to describe and understand the current precipitation variations over both ice sheets. Some sugges-tions are offered for steps that could be taken. 1. |
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