Characteristics of Bay of Bengal monsoon depressions in the 21st Century

Rastogi, D., Ashfaq, M., Leung, L. R., Ghosh, S., Saha, A., Hodges, K. ORCID: https://orcid.org/0000-0003-0894-229X and Evans, K. (2018) Characteristics of Bay of Bengal monsoon depressions in the 21st Century. Geophysical Research Letters, 45 (13). pp. 6637-6645. ISSN 0094-8276 doi: 10.1029/2018GL078756

Abstract/Summary

We show that 21st century increase in radiative forcing does not significantly impact the frequency of South Asian summer monsoon depressions (MDs) or their trajectories in the Coupled Model Intercomparison Project Phase 5 general circulation models (GCMs). A significant relationship exists between the climatological occurrences of MDs and the strength of the background upper (lower) tropospheric meridional (zonal) winds and tropospheric moisture in the core genesis region of MDs. Likewise, there is a strong relationship between the strength of the meridional tropospheric temperature gradient in the GCMs and the trajectories of MDs over land. While monsoon dynamics progressively weakens in the future, atmospheric moisture exhibits a strong increase, limiting the impact of changes in dynamics on the frequency of MDs. Moreover, the weakening of meridional tropospheric temperature gradient in the future is substantially weaker than its inherent underestimation in the GCMs. Our results also indicate that future increases in the extreme wet events are dominated by nondepression day occurrences, which may render the monsoon extremes less predictable in the future.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/78092
Item Type	Article
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > NCAS Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	American Geophysical Union
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