Multi sensor Analysis of Tropical Mesoscale Convective Systems Jian Yuan and R A Houze J Clim J Atmos Sci NASA A Train Symposium New Orleans 27 October 2010 Example of mesoscale convective systems MCSs Large areas of cold top Radar Echoes in the 3 MCSs 1458GMT 13 May 2004 Large rain areas Stratiform Precipitation Convective Precipitation Non precipitating anvil clouds of MCSs have not been studied very much Mesoscale Convective System Extensively studied Need to understand how anvil is related to the raining region A Train instruments make it possible to observe both raining and anvil components Three steps of analysis of multi sensor data 1 TB11 2 RAIN 3 GEOPROF 2B MODIS TB11 AMSR E combined to find cold centers raining areas Locate 1st closed contour Use 260 K threshold Use 1 mm h threshold for rain rate Associate pixels with nearest cold center Use 6 mm h threshold for heavy rain Define criteria for MCS that are reasonable for all these regions PDF of rain amount as a function of raining core properties Min TB11 over raining core MCS Criteria Systems whose raining cores have Area 2000 km2 Min TB11 220 Must have one dominant core with intense cells and accounting for 70 rain area 220 C 2000 km2 Size of raining core 56 all tropical rain MCSs Over the Whole Tropics Smallest 25 12 000 km2 Largest 25 40 000 km2 Superclusters MODIS AMSR E identifies MCSs separates out the anvil component CloudSat structure of the anvils Frequency of MCS anvils over tropics Bulk Properties of MCS anvils identified by 3 A Train instruments bulk width thickness seen by CloudSat Height km Internal MCS anvil structure seen by CloudSat Africa Indian Ocean Anvil structure shown by CloudSat Width and depth differs between land and ocean Reflectivity distribution suggests larger particles dominate at lower levels smaller aloft Reflectivity distribution weakens with distance from rain more quickly over land Anvil structure far from raining cores similar everywhere Anvil structure close to raining cores differs land to ocean Conclusions COMBINING 3 A TRAIN INSTRUMENTS Identifies MCS Separates them into raining and anvil components Allows anvils to be analyzed relative to raining component LEADS TO UNPRECEDENTED ANALYSES OF MCSs Global MCS climatology obtained Different categories of MCSs identified Anvil width depth and interior structure quantified Differences between land and ocean anvils identified End This research was supported by NASA grants NNX07AQ89G and NNX10AM28G
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