The main hypothesis in the project is that the AMO is an intrinsic oceanic mode and that the associated SST anomalies in Atlantic Ocean can impact the Indian Summer Monsoon through teleconnection.

In order to test our hypothesis, we will use the re-analysis and observed data as well as IPCC/CMIP5 simulations to explore the decadal to multi-decadal variability of Indian Summer Monsoon and the teleconnection with AMO.

Data: For the observed and re-analysis data, the surface air temperature data NansenSAT (1900-2006; Kuzmina et al., 2005) (in-house at the coordinating institute), 140-year historical data on Indian summer rainfall (Parthaasarathy et al., 1994),  the Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP) data (1979-2009) (Xie and Arkin, 1997), and the Hadley Centre sea ice and sea surface temperature (SST) data set (HadlSST, 1870-2100, Rayner et al., 2003) will be used. Furthermore, we will also use the re-analysis data such as ERA-Interim40 (1989-2002; Dee and Oppala, 2009), NCEP-NCAR (1948-2010; Kalnay et al., 1996) and the newly-developed century long atmospheric reanalysis data set (1900-2010; Compo et al. 2010).  Finally, the reconstructed Asian Monsoon Drought Index over the last millennium (Cook et al., 2010) and the reconstructed North Atlantic Oscillation (NAO) over the past 600 years (Cook et al., 2002) will be used for validating the models. 

Model tool: It should be emphasized that the global climate models are skilful to simulate the variability of Indian Monsoon Rainfall (IMR), in particular on the decadal time scale (Kucharski, et al., 2009). The pre-industry control simulation of BCM has been used to explore the teleconnetcion between the ISM and the AMO (Luo et al., 2009). We plan to use IPCC/CMIP5 simulations (Taylor et al., 2011, http://cmip-pcmdi.llnl.gov/cmip5/getting_started_CMIP5_ experiment.html) performed with the advanced Coupled Climate Models (CCMs) and Earth System Models (ESMs).  The coupled climate and Earth System Models will be validated using the above mentioned data and a few realistic models out of more than 40 models will be selected.

Analysis: Statistical methods will be used to study the output from the selected coupled and Earth System Models to identify decadal to multi-decadal variations and identify and understand potential teleconnection mechanism between AMO and AMDI in order to contribute to better prediction of IMR.