Open AccessA linear diagnosis of the coupled extratropical ocean–atmosphere system in the GFDL GCM
Author(s) -
Newman Matthew,
Alexander Michael A.,
Winkler Christopher R.,
Scott James D.,
Barsugli Joseph J.
Publication year - 2000
Publication title -
atmospheric science letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.951
H-Index - 45
ISSN - 1530-261X
DOI - 10.1006/asle.2000.0002
Subject(s) - barotropic fluid , extratropical cyclone , climatology , gcm transcription factors , forcing (mathematics) , climate model , environmental science , atmosphere (unit) , atmospheric model , geophysical fluid dynamics , general circulation model , atmospheric sciences , geology , climate change , meteorology , oceanography , geography
Abstract Diagnosing a coupled system with linear inverse modelling (LIM) can provide insight into the nature and strength of the coupling. This technique is applied to the cold season output of the GFDL GCM, forced by observed tropical Pacific SSTs and including a slab mixed layer ocean model elsewhere. It is found that extratropical SST anomalies act to enhance atmospheric thermal variability and diminish barotropic variability over the east Pacific in these GCM runs, in agreement with other theoretical and modelling studies. North‐west Atlantic barotropic variability is also enhanced. However, all these feedbacks are very weak. LIM results also suggest that North Pacific extratropical SST anomalies in this model would rapidly decay without atmospheric forcing induced by tropical SST anomalies. Copyright © 2000 Royal Meteorological Society.