EGU21-4880
https://doi.org/10.5194/egusphere-egu21-4880
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Global Teleconnections to the Indian Summer Monsoon in CFSv2 model: Tropics vs. Midlatitude

Priyanshi Singhai1,2, Arindam Chakraborty1,2, Kavirajan Rajendran3, and Sajani Surendran3
Priyanshi Singhai et al.
  • 1Centre for Atmospheric and Oceanic Science, Indian Institute of Science, Bengaluru, India (priyanshis@iisc.ac.in, arch@iisc.ac.in)
  • 2Divecha Centre for Climate Change, Indian Institute of Science, Bengaluru, India (priyanshis@iisc.ac.in, arch@iisc.ac.in)
  • 3CSIR Fourth Paradigm Institute, Bengaluru, India (rajend@csir4pi.in, sajani@csir4pi.in)

Traditionally, monsoon teleconnections are measured in terms of the strength of a simultaneous linear relationship. Such associative metrics do not quantify precipitation variations through physical parameters directly related to the moisture budget of the atmosphere. In this study, for the first time, we develop a linear model for the Indian summer monsoon rainfall (ISMR) based on surface pressure over regions surrounding it and sea surface temperature (SST) forcing from tropics and midlatitude. This surface pressure acts as a dynamical link between SST forcing and convective processes over the Indian region, which was missing in previous studies. We also use this novel approach to understand the ISMR prediction skill in the National Centers for Environmental Prediction (NCEP) Climate Forecast System version 2 (CFSv2). We find that the interannual variability of ISMR does not rely solely on tropical processes, but the midlatitude phenomenon also plays a crucial role in modulating it. The model, however, derived most of its variability from the ENSO mode. The understated midlatitude forcing in the model can be attributed to its low prediction skill. 

How to cite: Singhai, P., Chakraborty, A., Rajendran, K., and Surendran, S.: Global Teleconnections to the Indian Summer Monsoon in CFSv2 model: Tropics vs. Midlatitude, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-4880, https://doi.org/10.5194/egusphere-egu21-4880, 2021.

Corresponding presentation materials formerly uploaded have been withdrawn.