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Title: Low-frequency aspects of the large-scale circulation and West Coast United States temperature/precipitation fluctuations in a simplified general circulation model

Abstract

Behavior of regional precipitation and temperature over the West Coast of the United States was examined in a long perpetual winter simulation from a simplified global general circulation model. The model, a simplified version of the U.S. National Weather Service global operational forecast model, was run over a series of 568 winters, complete with geopotential, precipitation, and near-surface temperature. In spite of the fixed climatological boundary conditions, the simulated winter-mean precipitation and temperature anomalies have a fairly realistic low-frequency regional variability. Both synoptic-scale events and seasonal average behavior are produced quite realistically by the model. Like observations, the regional surface variations can be related to the large-scale low-frequency circulation. Four regional temperature/precipitation extremes - namely, warm/dry, cool/wet, cool/dry, and warm/wet - can be identified from the simulated winter-mean series over the West Coast. Associated with these four regional extremes, model Northern Hemisphere 500-mb height composites exhibit distinct planetary-scale circulation patterns. An empirical orthogonal function analysis further reveals that the first and third modes of the 500-mb height anomalies are primary contributors to these four regional extremes. The first mode largely governs the regional temperature variation, whereas the third mode largely determines the precipitation variation. 37 refs., 14 figs., 2 tabs.

Authors:
;  [1]
  1. Univ. of California, San Diego, La Jolla, CA (United States)
Publication Date:
OSTI Identifier:
54336
Resource Type:
Journal Article
Journal Name:
Journal of Climate
Additional Journal Information:
Journal Volume: 7; Journal Issue: 11; Other Information: PBD: Nov 1994
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; 99 MATHEMATICS, COMPUTERS, INFORMATION SCIENCE, MANAGEMENT, LAW, MISCELLANEOUS; GENERAL CIRCULATION MODELS; SEASONAL VARIATIONS; US WEST COAST; ATMOSPHERIC PRECIPITATIONS; AMBIENT TEMPERATURE; BOUNDARY CONDITIONS

Citation Formats

Chen, S C, and Cayan, D R. Low-frequency aspects of the large-scale circulation and West Coast United States temperature/precipitation fluctuations in a simplified general circulation model. United States: N. p., 1994. Web. doi:10.1175/1520-0442(1994)007<1668:LFAOTL>2.0.CO;2.
Chen, S C, & Cayan, D R. Low-frequency aspects of the large-scale circulation and West Coast United States temperature/precipitation fluctuations in a simplified general circulation model. United States. doi:10.1175/1520-0442(1994)007<1668:LFAOTL>2.0.CO;2.
Chen, S C, and Cayan, D R. Tue . "Low-frequency aspects of the large-scale circulation and West Coast United States temperature/precipitation fluctuations in a simplified general circulation model". United States. doi:10.1175/1520-0442(1994)007<1668:LFAOTL>2.0.CO;2.
@article{osti_54336,
title = {Low-frequency aspects of the large-scale circulation and West Coast United States temperature/precipitation fluctuations in a simplified general circulation model},
author = {Chen, S C and Cayan, D R},
abstractNote = {Behavior of regional precipitation and temperature over the West Coast of the United States was examined in a long perpetual winter simulation from a simplified global general circulation model. The model, a simplified version of the U.S. National Weather Service global operational forecast model, was run over a series of 568 winters, complete with geopotential, precipitation, and near-surface temperature. In spite of the fixed climatological boundary conditions, the simulated winter-mean precipitation and temperature anomalies have a fairly realistic low-frequency regional variability. Both synoptic-scale events and seasonal average behavior are produced quite realistically by the model. Like observations, the regional surface variations can be related to the large-scale low-frequency circulation. Four regional temperature/precipitation extremes - namely, warm/dry, cool/wet, cool/dry, and warm/wet - can be identified from the simulated winter-mean series over the West Coast. Associated with these four regional extremes, model Northern Hemisphere 500-mb height composites exhibit distinct planetary-scale circulation patterns. An empirical orthogonal function analysis further reveals that the first and third modes of the 500-mb height anomalies are primary contributors to these four regional extremes. The first mode largely governs the regional temperature variation, whereas the third mode largely determines the precipitation variation. 37 refs., 14 figs., 2 tabs.},
doi = {10.1175/1520-0442(1994)007<1668:LFAOTL>2.0.CO;2},
journal = {Journal of Climate},
number = 11,
volume = 7,
place = {United States},
year = {1994},
month = {11}
}