On the build-up of dust aerosols and possible indirect effect during Indian summer monsoon break spells using recent satellite observations of aerosols and cloud properties

Exacerbation of Indian Summer Monsoon Breaks by the Indirect Effect of Regional Dust Aerosols

“…The aerosol buildup over central India and the northern parts of MCZ in the break phase is conspicuous in CNTL‐PD (Figure S1 in Supporting Information ), as observed by Arya et al. (2021).…”

“…The aerosol buildup over central India and the northern parts of MCZ in the break phase is conspicuous in CNTL‐PD (Figure S1 in Supporting Information ), as observed by Arya et al. (2021). Anomalous westerly winds during the break phase lead to the transport of dust aerosols from the desert regions of West Asia and the Thar desert eastwards into the MCZ and result in enhanced aerosol loading represented as aerosol optical depth (AOD), over all of central India (Figure 2 and Figure S1 in Supporting Information ).…”

“…In turn, AOD and rain have links to cloud‐microphysics. Mineral dust is a dominant natural aerosol species, besides sea salt and its production is sensitive to winds, precipitation and surface characteristics. During the breaks, dust aerosols are observed to constitute the major part of total aerosols due to the abundance of mineral dust and the transport of desert dust (e.g., Arya et al., 2021). Consistently, in CNTL‐PD, a large fraction of the total AOD (AOD TOTAL ) is contributed by dust aerosols over India particularly over central India and MCZ (more than 50%) as can be gleaned from Figure S2 in Supporting Information .…”

“…Many observational studies examined the indirect effect of aerosols over India on monsoon rainfall and its variability (e.g., Harikishan et al., 2015; Manoj et al., 2012). The large‐scale circulation associated with the break phase was found to be instrumental in transporting dust to India (e.g., Arya et al., 2021; Prijith et al., 2013). However, a comprehensive understanding of the impacts of regional aerosols on ISM intraseasonal variability remains a goal per se because of the vast heterogeneity of aerosol types, their spatio‐temporal variations and the complex mechanisms involved, besides the interplay among various monsoon processes.…”

“…During break spells, the anomalous transport results in the buildup of absorbing aerosols or dust over India (e.g., Arya et al, 2021). Such buildup can cause changes in atmospheric heating through indirect impacts as hypothesized by Arya et al (2021) through the composite analysis of all the break spells during 2000-2020 using a suite of satellite observations of aerosol and cloud properties. Hence, it is imperative to investigate how the regional dust aerosols affect the monsoon ISV in particular the break spells using global aerosol distributions and associated dynamics.…”