HR: 1340h
AN: A13E-1605    [Abstracts]
TI: Analysis of the Synoptic Forcing for Precipitation Over Greenland From 1961 to 1999
AU: * Schuenemann, K C
EM: schuenem@colorado.edu
AF: Cooperative Institute for Research in Environmental Sciences and Department of Atmospheric and Oceanic Sciences at the University of Colorado, 216 UCB, Boulder, CO 80309, United States
AU: Cassano, J J
EM: cassano@cires.colorado.edu
AF: Cooperative Institute for Research in Environmental Sciences and Department of Atmospheric and Oceanic Sciences at the University of Colorado, 216 UCB, Boulder, CO 80309, United States
AB: Studying the synoptic climatology and precipitation patterns over the North Atlantic region is necessary in order to better understand the atmospheric input to the mass balance of the Greenland ice sheet. The self-organizing map (SOM) technique is applied to ERA-40 average daily sea-level pressure (SLP) data from 1961 to 1999 to objectively identify synoptic SLP patterns over the North Atlantic region. A total of 35 different SLP patterns were identified. Analysis of precipitation patterns associated with each SLP pattern revealed the various forcings for precipitation over portions of Greenland. In most cases the largest precipitation events are associated with passing cyclones, which create onshore flow, allowing for the air to be lifted orographically by the ice sheet. The southern portion of Greenland received the largest magnitudes of precipitation due to its extreme topography and its location near open water and, therefore, moist air. Each portion of Greenland has its own preferred synoptic pattern for receiving precipitation. The frequency and efficiency of these patterns to bring precipitation to Greenland were the focus of a trend analysis revealing that a slight increasing trend in precipitation from 1961 to 1999 was due to both circulation changes and thermodynamic changes near Greenland. This analysis will be repeated for 15 climate model predictions for the reanalysis period in order to evaluate the ability of the various climate models to reproduce the synoptic climatology of the North Atlantic region. The models that perform the best over the reanalysis period will be used to create a synoptic climatology for the twenty-first century for studying future trends in synoptic patterns and precipitation over Greenland.
DE: 0726 Ice sheets
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
DE: 3309 Climatology (1616, 1620, 3305, 4215, 8408)
DE: 3349 Polar meteorology
DE: 3364 Synoptic-scale meteorology
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting