2005: High resolution regional climate simulations over Iceland using Polar MM5

High-resolution regional climate simulations of Iceland for 1991–2000 have been performed using the fifth-generation Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) Mesocale Model (MM5) modified for use in polar regions (Polar MM5) with three nested domains and shor...

Full description

Bibliographic Details
Main Authors: David H. Bromwich, Lesheng Bai
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Subjects:
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.668.1103
http://polarmet.osu.edu/PMG_publications/bromwich_bai_mwr_2005.pdf
Description
Summary:High-resolution regional climate simulations of Iceland for 1991–2000 have been performed using the fifth-generation Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) Mesocale Model (MM5) modified for use in polar regions (Polar MM5) with three nested domains and short-duration integrations. The simulated results are compared with monthly mean surface observations from Iceland for 1991–2000 to demonstrate the high level of model performance; correlation coefficients exceed 0.9 for most variables considered. The simulation results are used to analyze the near-surface climate over Iceland. The simulated near-surface winds in winter are primarily katabatic. The land–sea-breeze circulation is clearly evident in sum-mer. The land is colder than the ocean during winter, with a strong (weak) temperature gradient along the southern (northern) coast. This temperature pattern over the sloping terrain forces the katabatic wind. The diurnal cycle of near-surface air temperature is marked in summer over the land areas, which drives the land–sea breeze. The near-surface climate variations for extremes of the North Atlantic Oscillation (NAO) index during winter and summer result from the large-scale atmospheric advection conditions. The time-averaged mesoscale precipitation distribution over Iceland is reasonably well simulated by