q 1998 American Meteorological Society Polar Climate Simulation of the NCAR CCM3*,1

• Main Authors: Bruce P. Briegleb, David H. Bromwich
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1997
• Subjects: Antarctic; Arctic; Arctic Ocean; The Antarctic; Antarc*
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.670.2789; http://polarmet.osu.edu/PMG_publications/briegleb_bromwich_jc_1998-2.pdf

Present-day Arctic and Antarctic climate of the National Center for Atmospheric Research (NCAR) Community Climate Model version 3 (CCM3) is presented. The CCM3 simulation is from a prescribed and interannually varying sea surface temperature integration from January 1979 through August 1993. Observations from a variety of sources, including the European Centre for Medium-Range Weather Forecasts analyses, rawinsonde, and surface station data, are used for validation of CCM3’s polar climate during this period. Overall, CCM3 can simulate many important polar climatic features and in general is an incremental improvement over CCM2. The 500-hPa polar vortex minima are too deep by 50–100 m and too zonally symmetric. The Arctic sea level pressure maximum is displaced poleward, while the Icelandic region minimum is extended toward Europe, and the Aleutian region minimum is extended toward Asia. The Antarctic circumpolar trough of low sea level pressure is slightly north of the observed position and is 2–3 hPa too low. Antarctic katabatic winds are similar to observations in magnitude and regional variation. The Antarctic surface wind stress is estimated to be 30%– 50 % too strong in some regions. Polar tropospheric temperatures are 28–48C colder than observations, mostly in the summer season. Low-level winter inversions over the Arctic Ocean are only 38–48C, rather than the observed 108C. In the Antarctic midcontinent they are around 258–308C (about 58 stronger than observed) and