Slide 1Slide 2Slide 3Slide 4A-Train instruments make it possible to observe both raining and anvil componentsSlide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Anvil structure shown by CloudSatSlide 16Slide 17Multi-sensor Analysis of Tropical Mesoscale Convective SystemsJian Yuan and R. A. Houze [J. Clim., J. Atmos. Sci.]NASA A-Train Symposium, New Orleans, 27 October 2010Example of mesoscale convective systems“MCSs”Large areasof cold top1458GMT 13 May 2004ConvectivePrecipitationStratiformPrecipitationRadar Echoes in the 3 MCSsLarge rainareasNon-precipitating “anvil clouds” of MCSs have not been studied very muchExtensively studiedNeed to understand how anvil is related to the raining regionMesoscale Convective SystemA-Train instruments make it possible to observe both raining and anvil components1 2 3Three steps of analysis of multi-sensor data(TB11)(GEOPROF-2B)(RAIN)MODIS TB11 + AMSR-Ecombined to find“cold centers” & “raining areas”Use 260 K thresholdLocate 1st closed contourUse 1 mm/h threshold for rain rateAssociate pixels with nearest cold centerUse 6 mm/h threshold for heavy rainDefine criteria for MCS that are reasonable for all these regionsMCS CriteriaSystems whose raining cores have•Area > 2000 km2•Min TB11 ≤ 220 PDF of rain amount as a function of raining core propertiesSize of raining coreMin TB11 over raining coreMust have one dominant core •with intense cells, and•accounting for >70% rain area56% all tropical rain2000 km2220°CMCSs Over the Whole TropicsSmallest 25% (<12,000 km2)Largest 25% (>40,000 km2)“Superclusters”MODIS/AMSR-E identifies MCSs separates out the anvil componentCloudSat structure of the anvilsFrequency of MCS anvils over tropicsBulk Properties of MCS anvils •identified by 3 A-Train instruments•bulk width & thickness seen by CloudSatAfricaIndian OceanHeight (km)Internal MCS anvil structure seen by CloudSatAnvil 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 oceanConclusionsCOMBINING 3 A-TRAIN INSTRUMENTS•Identifies MCS•Separates them into raining and anvil components•Allows anvils to be analyzed relative to raining componentLEADS 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 identifiedEndThis research was supported by NASA grantsNNX07AQ89G and
View Full Document
Unlocking...