Climate and Dynamics
Modulation of ISOs by land-atmosphere feedback and contribution to the interannual variability of Indian summer monsoon
Article first published online: 3 JUL 2012
©2012. American Geophysical Union. All Rights Reserved.
Journal of Geophysical Research: Atmospheres (1984–2012)
Volume 117, Issue D13, 16 July 2012
How to Cite
2012), Modulation of ISOs by land-atmosphere feedback and contribution to the interannual variability of Indian summer monsoon, J. Geophys. Res., 117, D13101, doi:10.1029/2011JD017291., , , and (
- Issue published online: 3 JUL 2012
- Article first published online: 3 JUL 2012
- Manuscript Accepted: 22 MAY 2012
- Manuscript Revised: 21 MAY 2012
- Manuscript Received: 8 DEC 2011
- land-atmosphere interaction;
- monsoon ISOs
 A mechanism of internal variability of Indian summer monsoon through the modulation of intraseasonal oscillation (ISO) by land-atmosphere feedback is proposed. Evidence of feedback between surface soil moisture and ISOs is seen in the soil moisture data from GSWP-2 and rainfall data from observations. Using two sets of internal simulation by a regional climate model (RCM), it is shown that internally generated anomalous soil moisture interacts with the following ISO and generates interannual variability. To gain further insight, 27 years of sensitivity experiment by prescribing wet (dry) soil moisture condition during break (active) period along with a control simulation are carried out. The sensitivity experiment reveals the large-scale nature of soil moisture and ISO feedback which takes place through the changes in atmospheric stability by altering lower-level atmospheric conditions. The feedback is inherent to the monsoon system and a part of it acts through the intraseasonal varying memory of soil moisture. The RCM used to test the hypothesis is constrained by one-way interactions at the lateral boundary. Experiments with a much larger domain upheld the findings and hence suggest the true nature of soil moisture and ISO feedback present in the monsoon system.