Journal Article

FZJ-2021-03043

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png The impact of COVID-19 lockdown measures on the Indian summer monsoon

Fadnavis, S. (Corresponding author) ; Sabin, T. P. ; Rap, A. ; Müller, R.FZJ* ; Kubin, A. ; Heinold, B.

2021
IOP Publ. Bristol

This record in other databases:    

Please use a persistent id in citations: http://hdl.handle.net/2128/28254  doi:10.1088/1748-9326/ac109c

Abstract: Aerosol concentrations over Asia play a key role in modulating the Indian summer monsoon (ISM)rainfall. Lockdown measures imposed to prevent the spread of the COVID-19 pandemic led tosubstantial reductions in observed Asian aerosol loadings. Here, we use bottom-up estimates ofanthropogenic emissions based on national mobility data from Google and Apple, along withsimulations from the ECHAM6-HAMMOZ state-of-the-art aerosol-chemistry-climate model toinvestigate the impact of the reduced aerosol and gases pollution loadings on the ISM. We showthat the decrease in anthropogenic emissions led to a 4 W m−2 increase in surface solar radiationover parts of South Asia, which resulted in a strengthening of the ISM. Simultaneously, whilenatural emission parameterizations are kept the same in all our simulations, the anthropogenicemission reduction led to changes in the atmospheric circulation, causing accumulation of dustover the Tibetan plateau (TP) during the pre-monsoon and monsoon seasons. This accumulateddust has intensified the warm core over the TP that reinforced the intensification of the Hadleycirculation. The associated cross-equatorial moisture influx over the Indian landmass led to anenhanced amount of rainfall by 4% (0.2 mm d−1) over the Indian landmass and 5%–15%(0.8–3 mm d−1 ) over central India. These estimates may vary under the influence of large-scalecoupled atmosphere–ocean oscillations (e.g. El Nino Southern Oscillation, Indian Ocean Dipole).Our study indicates that the reduced anthropogenic emissions caused by the unprecedentedCOVID-19 restrictions had a favourable effect on the hydrological cycle over South Asia, which hasbeen facing water scarcity during the past decades. This emphasizes the need for stringentmeasures to limit future anthropogenic emissions in South Asia for protecting one of the world’smost densely populated regions.

---

Contributing Institute(s):

1. Stratosphäre (IEK-7)

Research Program(s):

1. 2112 - Climate Feedbacks (POF4-211) (POF4-211)

Appears in the scientific report 2021

---

Database coverage:
; ; ; ; Article Processing Charges ; Clarivate Analytics Master Journal List ; Current Contents - Agriculture, Biology and Environmental Sciences ; Current Contents - Physical, Chemical and Earth Sciences ; DOAJ Seal ; Essential Science Indicators ; Fees ; IF >= 5 ; JCR ; Nationallizenz ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

---