Cloud/Cryosphere Interactions
Major objectives included investigating cryospheric dynamics, particularly relationships and feedbacks between clouds and the cryosphere when snow cover is forming or dissipating, and assessing algorithms and climatologies used in A.F. operational snow and cloud cover products. Study results have le...
Main Authors: | , |
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Format: | Text |
Language: | English |
Published: |
1989
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Online Access: | http://www.dtic.mil/docs/citations/ADA208377 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA208377 |
Summary: | Major objectives included investigating cryospheric dynamics, particularly relationships and feedbacks between clouds and the cryosphere when snow cover is forming or dissipating, and assessing algorithms and climatologies used in A.F. operational snow and cloud cover products. Study results have led to increased understanding of: 1) seasonal and interannual variations in snow and cloud cover, 2) dynamics of the onset of melt season in arctic regions, 3) performance of A.F. nephanalyses in marginal cryosphere regions, and 4) performance of the A.F. SNODEP model. Project results include: 1) Cloud cover in the Arctic Basin has a late May-early June maximum in extent and thickness, followed by a period of less extensive and thinner cover extending into early August. Cloud conditions are associated with the distribution of surface pressure and the flow of air into the Basin at the surface and aloft. 2) Over arctic lands and sea ice, the timing and duration of the snow melt season, which strongly influence surface mobility of personnel and machinery, vary geographically within a year and across the region from year to year. 3) Increased spring cloudiness and onset of the melt season over sea ice coincide, suggesting that both are related to northward transport of moist air into the Basin by synoptic disturbances, rather than one solely driving the other. Results over arctic lands are less conclusive. Varying conditions of snow pack, surface albedo, seasonal and latitudinal distribution of solar insolation reaching the top of the atmosphere are among other factors influencing melt. 4) A southward shift in the mid-winter snow line was found over the central U.S. in the past 50 years. |
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