Modeled variations of precipitation over the Greenland Ice Sheet

Journal Article · Thu Jul 01 04:00:00 EDT 1993 · Journal of Climate; (United States)

DOI:https://doi.org/10.1175/1520-0442(1993)006<1253:MVOPOT>2.0.CO;2· OSTI ID:5572145

Bromwich, D H; Robasky, F M; Bolzan, J F ^[1]; Keen, R A

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1. Ohio State Univ., Columbus, OH (United States)

A parameterization of the synoptic activity at 500 hPa and a simple orographic scheme are used to model the spatial and temporal variations of precipitation over the Greenland Ice Sheet for 1963-88 from information from the National Meteorological Center (NMC). Most major spatial characteristics of the observed accumulation distribution are reproduced. The modeled time-averaged total precipitation amount over Greenland is within the range of values determined by other investigators from surface-based observations. A downward trend in simulated ice sheet precipitation over the 26 years is found, supported by a number of lines of evidence. This negative precipitation trend would mean that the Greenland Ice Sheet, depending on its 1963 mass balance state, has over the 1963-88 period either decreased its negative, or increased its positive, contribution to recently observed global sea level rise. Superimposed on the declining simulated precipitation rate for the entire ice sheet is a pronounced 3-5-yr periodicity. This is prominent in the observed and modeled precipitation time series from Summit, Greenland. This cycle shows some aspects in common with the Southern Oscillation. Some deficiencies in the NMC analyses were highlighted by this work. A large jump in simulated precipitation amounts at Summit around 1962, which is not verified by accumulation data, is inferred to be due to an artificial increase in cyclonic activity at 500 hPa associated with the NMC change from manual to numerical analyses. The activity of the storm track along the west coast of Greenland appears to be anomalously low in the NMC analyses, perhaps due to mesoscale cyclogenesis that is not resolved by the NMC analysis scheme. 71 refs., 21 figs., 1 tab.

• OSTI ID: 5572145
• Journal Information: Journal of Climate; (United States), Journal Name: Journal of Climate; (United States) Vol. 6:7; ISSN JLCLEL; ISSN 0894-8755
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540110*
ANNUAL VARIATIONS
ATMOSPHERIC PRECIPITATIONS
GREENLAND
MATHEMATICAL MODELS
VARIATIONS