Unique roll clouds along the flow path of the Indian summer monsoon low-level jet over the Arabian sea.

ABSTRACT: Unique boundary layer roll clouds in the form of parallel straight lines are formed along the flow path of the Arabian Sea branch (ASB) of the Indian summer monsoon low-level jet. An attempt has been made in this study to understand the mechanism behind their formation using high-resolution NOAA-20 satellite imageries and ECMWF reanalysis data. Thermal and dynamical instabilities generated by the ASB of the low-level jet in the atmospheric boundary layer produce eddies in the primary flow of the ASB which organize themselves as counter rotating roll vortices. Roll clouds form over ascending regions of these vortices and clear-sky condition prevails over descending regions. Bulk Richardson number computed between 1000 hPa and 975 hPa levels highlight the instability regimes that support the

SUBMITTER: Swathi B 

PROVIDER: S-EPMC11994763 | biostudies-literature | 2025 Apr

REPOSITORIES: biostudies-literature