Reply to Comment by E. T. Swenson, D. Das, and J. Shukla on “Unraveling the Mystery of Indian Summer Monsoon Prediction: Improved Estimate of Predictability Limit”

Abstract

(hereafter SN20) raise some technical issues on observed correlations between the synoptic variances and the seasonal mean of area averaged (all-India or central India) Indian summer monsoon rainfall (ISMR) reported in Saha et al. (2019,

Role of Microphysics and Convective Autoconversion for the Better Simulation of Tropical Intraseasonal Oscillations (MISO and MJO)

“…(2021) and S. K. Saha et al. (2019, 2020) study. The same methodology was also used in Swenson et al.…”

“…The proper combination of both “autoconversion” coefficients ( C MA and C CA ) can help to encapsulate the synoptic activity (e.g., lows, depression, cyclones, etc. ), which in turn affects the seasonal mean ISMR (S. K. Saha et al., 2020). These are the large rain‐bearing systems (i.e., lows, depressions, and cyclones), which primarily passed through central India (recognized as a homogeneous rainfall region) and determines the seasonal accumulated rainfall (Goswami, 1998; Goswami et al., 2003).…”

“…MJO) induces a local transient Hadley circulation, which further modulates the monsoon. Previous studies (Lau & Chan, 1988; Lau & Shen, 1988; Weickmann, 1991) demonstrated that eastward propagation of MJO convective activities can modulate the evolution of ENSO, which again modulates ISO as well as synoptic activity of ISM through teleconnection mechanisms (S. Saha et al., 2021; S. K. Saha et al., 2019, 2020). Hence, it is important to better simulate these two tropical oscillations (ISO and MJO) in Coupled Global Climate Models (CGCM) which will complement each other to improve the skill of dynamical models (Goswami & Goswami, 2017; Hendon et al., 2000; Jiang et al., 2015; Ling et al., 2017; Rajeevan et al., 2012; Yang & Wang, 2019).…”

Interplay Between Subseasonal Rainfall and Global Predictors in Modulating Interannual to Multidecadal Predictability of the ISMR

“…Some recent studies suggest that ISMR may be more predictable than it was thought before (Dwivedi et al, 2015;Saha et al, 2019Saha et al, , 2020. In general, we seek a linear relationship between the predictors and predictand to estimate the signal or predictable component.…”

Role of mean, variability and teleconnection of clouds behind Indian summer monsoon rainfall

“…The active and break spells are also influenced by the spatial clustering of synoptic activities during ISM (Goswami et al, 2003). Later, Saha et al (2019, 2020, 2021) have also showed that the synoptic variance of rainfall is strongly coupled with mean ISMR and also likely to be predictable due to its association with large‐scale predictors (e.g., ENSO). Ganai et al (2016) have also pointed out that the improved understanding of the parameterization scheme in the CFS model may lead to the proper simulation of observed diurnal variability in active and break phases.…”