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DO WE KNOW HOW STORMS WILL CHANGE IN A WARMING CLIMATE?. William B. Rossow NOAA CREST at The City College of New York June 2013. Mythical Answer : YES Because T↑ => Q ↑ => Clouds & Precip ↑ Fantasy Answer : YES Because the Models say so Best Answer : NO. Prior Questions.
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DO WE KNOW HOW STORMS WILL CHANGE IN A WARMING CLIMATE? William B. Rossow NOAA CREST at The City College of New York June 2013
Mythical Answer: YES Because T↑ => Q ↑ => Clouds & Precip↑ • Fantasy Answer: YES Because the Models say so • Best Answer: NO
Prior Questions • What is the current day distribution of storm strengths? • Only recently completed surveys now revealing key details • What causes the rarer stronger storms? • Better precipitation & radiation datasets now allow diagnosis • How are weak and strong storms coupled to the general circulation? • Different heating but not known -- here is an approach
HEAT TRANSPORT IMPLIED BY RADIATIVE IMBALANCE BY OCEAN BY ATMOSPHERE
CloudSat and tropical cyclones -- So far we have intersected the eyes of 4 different tropical cyclones 20 Eye 20 10 Height (km) 0 -10 -20 -30 0 B Hurricane Ileana MODIS 12 µm (Channel 32) 23 Aug 2006 2100 UTC A A B CloudSat Radar Reflectivity (dBZ) 10
COMPARISON OF ORDINARYTO ORGANIZED CONVECTION WS3 WS1 CLOUDSAT VIEW
LW CRE at Surface & TOAAtmospheric Heating/Cooling Cooling Cooling Heating Heating
Composite of Diabatic Heating of Atmosphere with Cyclone Strength PRECIP RAD
SO WE KNOW THAT STORMS HEAT THE ATMOSPHERE • WE KNOW THAT THERE IS A WIDE RANGE OF STORM TYPES AND STRENGTHS • WE DON’T KNOW HOW THESE DIFFERENT STORMS ARE COUPLED TO THE GENERAL CIRCULATION • SO WE DON’T KNOW HOW THEY WILL CHANGE IN A WARMING CLIMATE • BUT HERE IS WHAT WE CAN DO
Analysis Approaches • Tropics: Track Mesoscale Convective Systems, Develop Convective Classification, Investigate Convection Initiation & Dynamics (High Time Resolution), Develop Lagrangian Correspondence of Environment & Convective Types, Conduct Large-Domain CRM & GCM Experiments • Midlatitudes: Track Cyclones, Develop Cyclone Classification, Diagnose Diabatic Heating Processes, Investigate Internal (Lagrangian) Heating & Dynamics, Conduct GCM Experiments • Global: Global Weather States & Properties, Indices of Strength of General Circulation, Investigate GWS Distributions & Changes with Circulation Strength, Conduct GCM Experiments
ISCCP GLOBAL WEATHER STATES ISCCP GLOBAL WEATHER STATES