The influence of Atlantic variability on Asian summer climate is sensitive to the pattern of the sea surface temperature anomaly

Ratna, Satyaban B., Osborn, Timothy J., Joshi, Manoj and Luterbacher, Jürg (2020) The influence of Atlantic variability on Asian summer climate is sensitive to the pattern of the sea surface temperature anomaly. Journal of Climate, 33 (17). 7567–7590. ISSN 0894-8755

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We simulate the response of Asian summer climate to AMO-like (Atlantic Multidecadal Oscillation) sea surface temperature (SST) anomalies using an Intermediate complexity General Circulation Model (IGCM4). Experiments are performed with seven individual AMO SST anomalies obtained from CMIP5/PMIP3 global climate models as well as their multi-model mean, globally and over the North Atlantic Ocean only, for both the positive and negative phases of the AMO. During the positive (warm) AMO phase, a Rossby wave train propagates eastward, causing a high pressure and warm and dry surface anomalies over eastern China and Japan. During the negative (cool) phase of the AMO, the mid-latitude Rossby wave train is less robust, but the model does simulate a warm and dry South Asian monsoon, associated with the movement of the Intertropical Convergence Zone in the tropical Atlantic. The circulation response and associated temperature and precipitation anomalies are sensitive to the choice of AMO SST anomaly pattern. A comparison between global SST and North Atlantic SST perturbation experiments indicates that East Asian climate anomalies are forced from the North Atlantic region, whereas South Asian climate anomalies are more strongly affected by the AMO-related SST anomalies outside the North Atlantic region. Experiments conducted with different amplitudes of negative and positive AMO nomalies show that the temperature response is linear with respect to SST anomaly, but the precipitation response is nonlinear.

Item Type: Article
Additional Information: Data Availability Statement. The composite mean AMO SST patterns and the model-simulated data used for this manuscript are available at the Centre for Environmental Data Analysis (CEDA) archive at
Faculty \ School: Faculty of Science > School of Environmental Sciences
Depositing User: LivePure Connector
Date Deposited: 17 Jun 2020 00:13
Last Modified: 31 Aug 2020 23:54
DOI: 10.1175/JCLI-D-20-0039.1

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