Properties of deep convection in tropical continental, monsoon, and oceanic rainfall regimes

• Published in: Geophysical research letters Vol. 39; no. 7
• Main Authors: Xu, Weixin, Zipser, Edward J.
• Format: Journal Article
• Language: English
• Published: Washington, DC Blackwell Publishing Ltd 01.04.2012; American Geophysical Union; John Wiley & Sons, Inc
• Subjects: and oceanic regimes; Atmospheric sciences; continental; continental, monsoon, and oceanic regimes; convective structures; Earth sciences; Earth, ocean, space; Exact sciences and technology; Freezing; Lightning; mixed-phase processes; monsoon; monsoon actives and breaks; Monsoons; Oceanic convection; Precipitation; Rainfall; Remote sensing; TRMM climatology; tropical deep convection; Updraft; rainfall; Water drop; atmospheric precipitation; Space remote sensing; Regional scope; tropical zone; Satellite observation; ice; Modeling; intensity; Snow pellets; freezing; raindrops; separation; Lightning; Icing; TRMM satellite; monsoons; Radar echo; storms; Atmospheric electricity
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2012GL051242

This study compares vertical structures and properties of deep convection for continental, monsoonal, and oceanic rainfall regimes based on 13‐yr TRMM measurements. There is evident regime separation in convective structures and properties of deep convection: continental and oceanic regimes are at two ends of the spectrum, with monsoon regimes intermediate between them. For example, most of the continental rainfall (70–80%) is contributed by storms having 40‐dBZ radar echoes reaching above 6‐km, strong ice scattering signature, and lightning flashes. This indicates that continental convection is dominated by robust mixed‐phase processes such as freezing of raindrops or riming of graupel supported by strong updrafts. In contrast, less monsoon rainfall (∼40%) or very limited oceanic rainfall (∼10%) involves these vigorous microphysical processes in mixed‐phase regions. Though monsoons are intermediate in convective intensity, both current and previous studies show that their active periods are closer to oceanic regimes and their break periods are slightly closer to continental regimes. In short, this study offers novel guidance for categorization of convective properties of three regime archetypes and will be important for future regional, climatological, and modeling studies. Key Points Clear regime separation exists among continent, monsoon, and oceanic convection Regime variations are most evident in mixed‐phase precipitation processes Monsoon actives (breaks) are slightly more continental (oceanic) in nature