Authors: Hai Wang Qinyu Liu
Publish Date: 2014/05/15
Volume: 31, Issue: 4, Pages: 916-925
Abstract
Experimental outputs of 11 Atmospheric Model Intercomparison Project AMIP models from phase 5 of the Coupled Model Intercomparison Project CMIP5 are analyzed to assess the atmospheric circulation anomaly over Northern Hemisphere induced by the anomalous rainfall over tropical Pacific and Indian Ocean during boreal winter The analysis shows that the main features of the interannual variation of tropical rainfall anomalies especially over the Central Pacific CP 5°S5°N 175°E135°W and Indowestern Pacific IWP 20°S20°N 110°–150°E are well captured in all the CMIP5/AMIP models For the IWP and western Indian Ocean WIO 10°S10°N 45°–75°E the anomalous rainfall is weaker in the 11 CMIP5/AMIP models than in the observation During El Niño/La Niña mature phases in boreal winter consistent with observations there are geopotential height anomalies known as the Pacific North American PNA pattern and Indowestern Pacific and East Asia IWPEA pattern in the upper troposphere and the northwestern Pacific anticyclone cyclone NWPA in the lower troposphere in the models Comparison between the models and observations shows that the ability to simulate the PNA and NWPA pattern depends on the ability to simulate the anomalous rainfall over the CP while the ability to simulate the IWPEA pattern is related to the ability to simulate the rainfall anomaly in the IWP and WIO as the SST anomaly is same in AMIP experiments It is found that the tropical rainfall anomaly is important in modeling the impact of the tropical IndoPacific Ocean on the extratropical atmospheric circulation anomaly
Keywords: