The effect of doubled CO2 and model basic state biases on the monsoon‐ENSO system. I: Mean response and interannual variability

The impact of doubled CO2 concentration on the Asian summer monsoon is studied using a coupled ocean‐atmosphere model. Both the mean seasonal precipitation and interannual monsoon variability are found to increase in the future climate scenario presented. Systematic biases in current climate simulat...

Full description

Saved in:
Bibliographic Details
Published in:Quarterly journal of the Royal Meteorological Society 2007-07, Vol.133 (626), p.1143-1157
Main Authors: Turner, A. G., Inness, P. M., Slingo, J. M.
Format: Article
Language:English
Subjects:
Earth, ocean, space
El Niño
Exact sciences and technology
External geophysics
India
interdecadal variability
Meteorology
Physics of the high neutral atmosphere
predictability
systematic error
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The impact of doubled CO2 concentration on the Asian summer monsoon is studied using a coupled ocean‐atmosphere model. Both the mean seasonal precipitation and interannual monsoon variability are found to increase in the future climate scenario presented. Systematic biases in current climate simulations of the coupled system prevent accurate representation of the monsoon‐ENSO teleconnection, of prime importance for seasonal prediction and for determining monsoon interannual variability. By applying seasonally varying heat flux adjustments to the tropical Pacific and Indian Ocean surface in the future climate simulation, some assessment can be made of the impact of systematic model biases on future climate predictions. In simulations where the flux adjustments are implemented, the response to climate change is magnified, with the suggestion that systematic biases may be masking the true impact of increased greenhouse gas forcing. The teleconnection between ENSO and the Asian summer monsoon remains robust in the future climate, although the Indo‐Pacific takes on more of a biennial character for long periods of the flux‐adjusted simulation. Assessing the teleconnection across interdecadal timescales shows wide variations in its amplitude, despite the absence of external forcing. This suggests that recent changes in the observed record cannot be distinguished from internal variations and as such are not necessarily related to climate change. Copyright © 2007 Royal Meteorological Society
ISSN:0035-9009
1477-870X
DOI:10.1002/qj.82