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A new perspective on MST radar observations of stratospheric intrusions into‐troposphere associated with tropical cyclone
Author(s) -
Das Siddarth Shankar
Publication year - 2009
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2009gl039184
Subject(s) - troposphere , tropical cyclone , climatology , stratosphere , environmental science , perspective (graphical) , geology , atmospheric sciences , atlantic hurricane , tropical cyclone rainfall forecasting , radar , meteorology , cyclone (programming language) , geography , field programmable gate array , computer science , computer hardware , telecommunications , artificial intelligence
This paper presents the first ever evidence of stratospheric intrusion into troposphere during the passage of tropical cyclone using mesosphere‐stratosphere‐troposphere (MST) radar located at Gadanki (13.5°N, 79.2°E). The most significant and new observation is the enhanced signal‐to‐noise ratio (SNR) of thickness ∼1 km, extended from 16–13 km, when the cyclone is located close to the radar site. Small‐scale turbulence and strong downdraft followed by weak updraft are also observed from spectral‐width and vertical velocity, respectively. Further analysis of global data shows low out‐going long wave radiation (<170 W m −2 ), low tropopause temperature (<191 K), enhanced potential vorticity (∼1 PVU) in the upper/middle troposphere, and low specific humidity (∼2 × 10 −4 kg/kg) at 300 hPa pressure level, occurs over the radar site. These observations clearly indicate the evidence of stratospheric intrusion into troposphere during the passage of tropical cyclone. The results are presented and discussed in the light of present understanding.