Convective genesis of cirrus clouds above the Asian monsoon tropopause from StratoClim airborne measurements, satellite observations and meteorological analysis - INSU - Institut national des sciences de l'Univers Accéder directement au contenu
Communication Dans Un Congrès Année : 2020

Convective genesis of cirrus clouds above the Asian monsoon tropopause from StratoClim airborne measurements, satellite observations and meteorological analysis

Sergey Khaykin

Résumé

Deployment of the high-altitude M55-Geophysica aircraft in Kathmandu within the StratoClim campaign in Summer 2017 has yielded a wealth of unique high-resolution measurements in the lower stratosphere above the Asian Monsoon Anticyclone (AMA). We combine the airborne measurements of clouds, water vapour and other convective tracers with satellite observations of cloud tops and high-resolution meteorological analysis by ECMWF Integrated Forecasting System to explore the convective influence on the formation and physical properties of the clouds above the AMA tropopause. We provide evidence for the stratospheric clouds of different genesis: convectively-injected clouds, secondary clouds condensing from a convectively-moistened patch of air, and in situ clouds forming at background levels of water vapour and modulated by orographic and/or convective gravity waves. Special attention is given to a particular flight, in which the aircraft flew through active stratospheric overshoots and sampled convective outflows above the tropopause minutes to hours old. The measurements reveal up to 2500 ppmv of ice water above 17 km in large aggregates measuring up to 750 μm in diameter. The tracer measurements show striking perturbations reflecting vigorous vertical motions and provide evidence for rapid mixing of tropospheric and stratospheric air around the tropopause. Our analysis suggests that the climatological maximum of stratospheric cirrus above AMA during August is a result of two concurrent processes: i) hydration by overshooting convection in the subtropical parts of AMA and ii) tropopause cooling induced by large-scale organized convective systems above Southern Asia. We discuss the dehydration potential of different types of clouds as well as the role of gravity waves in modulation of the three-dimensional cloud structure.
Fichier non déposé

Dates et versions

insu-04462383 , version 1 (16-02-2024)

Identifiants

Citer

Sergey Khaykin, M. Krämer, E. J. Moyer, A. Lykov, S. Bucci, et al.. Convective genesis of cirrus clouds above the Asian monsoon tropopause from StratoClim airborne measurements, satellite observations and meteorological analysis. American Geophysical Union, Fall Meeting 2020, Dec 2020, Online, Unknown Region. pp.abstract #A140-02. ⟨insu-04462383⟩
3 Consultations
0 Téléchargements

Partager

Gmail Facebook X LinkedIn More