The Indian Easterly Jet During the pre-monsoon season in India

Croad, H. L., Shonk, J. K. P., Chevuturi, A. ORCID: https://orcid.org/0000-0003-2815-7221, Turner, A. G. ORCID: https://orcid.org/0000-0002-0642-6876 and Hodges, K. I. ORCID: https://orcid.org/0000-0003-0894-229X (2023) The Indian Easterly Jet During the pre-monsoon season in India. Geophysical Research Letters, 50 (23). e2023GL105400. ISSN 0094-8276 doi: 10.1029/2023GL105400

Abstract/Summary

We identify for the first time an Indian Easterly Jet (IEJ) in the mid-troposphere during the pre-monsoon using reanalysis data. The IEJ is weaker and smaller than the African Easterly Jet over West Africa, with a climatological location of 10°N, 60–90°E, 700 hPa, and strength 6–7 m s−1 during March–May. The IEJ is a thermal wind associated with low-level meridional gradients in temperature (positive) and moisture (negative), resulting from equatorward moist convection and poleward dry convection. The IEJ is associated with a negative meridional potential vorticity gradient, therefore satisfying the Charney-Stern necessary condition for instability. However, no wave activity is detected, suggesting that the potential for combined barotropic-baroclinic instability is not often realized. IEJ strong (weak) years feature increased (reduced) near-surface temperatures and drier (wetter) conditions over India. This study provides an introduction to the IEJ's role in pre-monsoon dynamics, and a platform for further research.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/114235
Identification Number/DOI	10.1029/2023GL105400
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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