The analysis of the morphology of tropical convective systems has received much attention mainly thanks to the advent of geostationary infrared data. Statistics on the size, duration, propagation of the systems as well as the link to the thermodynamical and dynamical environment is readily acquired. Climatology of the tropical systems morphology is now built from roughly 25 years of continuous observations (e.g., Fiolleau et al., 2007).
On the other hand most of our knowledge on the life cycle of the tropical systems from a physical point of view (rainfall distribution, latent heating and radiation cooling rate vertical distribution, water transport, shear etc…) mainly arises from individual observational campaigns heavily based on ground radar observations and CRM modelling. Use of event-based approach exploiting the TRMM/PR data improves greatly the situation (Liu et al, 2008). The Megha-Tropiques mission, thanks to its sampling offers the possibility to further bridge the numerous individual case study physical observations and the climatological morphological approach (e.g. Kondo et al. 2006, Futyan and Del Genio, 2007).
The present product introduces a compositing technique aiming at such endeavor.
Level-2 product: Tracking of the Convective Cloud Systems
Composites are formed for each season over a suite of regions that cover the rainfall seasonal variability. For each regional box, cloud systems composite are constructed separating the land, ocean and coastal systems. The figure below illustrates the product.
Figure 2: Example of the final composite product constructed here over many seasons of TRMM/TMI and METEOSAT observations.
An in-depth description of the product is available here. For more information, contact fiolleau@lmd.polytechnique.fr and roca@lmd.jussieu.fr.
References:
Arnaud Y, Desbois M, Maizi J, 1992. Automatic tracking and characterization of African convective systems on meteosat pictures, Journal of Applied Meteorology, 31: 443-453.
Fiolleau et al, A climatology of Mesoscale Convective Systems from 23-years of METEOSAT first generation observations, AMMA conference, november 26,30 2009; article to be submitted
Futyan and Del Genio,2007, Deep Convective System Evolution over Africa and the Tropical Atlantic, J Climate, pp 5041-5060, DOI: 10.1175/JCLI4297.1
Kondo, Y, A. Higuchi and K. Nakamura, 2006: small-scale cloud activity over the maritime continent and the western Pacific as revealed by satellite data. Mon. Wea. Rev., 134, 1581-1599.
Liu, C., E.J. Zipser, D.J. Cecil, S.W. Nesbitt, and S. Sherwood, 2008: A Cloud and Precipitation Feature Database from Nine Years of TRMM Observations. J. Appl. Meteor. Climatol., 47, 2712-2728.
Mathon V, Laurent H. Life cycle of Sahelian mesoscale convective cloud systems. Quart J Roy Meteor Soc 2001 ; 72 : 105-10