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

TOA NET RADIATION & CLOUD EFFECTS

SRF NET RADIATION & CLOUD EFFECTS

HEAT TRANSPORT IMPLIED BY RADIATIVE IMBALANCE BY ATMOSPHERE BY OCEAN

ATM NET LW RAD & CLOUD EFFECTS

Hurricane Ileana A B MODIS 12 µm (Channel 32) 23 Aug UTC 10 CloudSat Radar Reflectivity (dBZ) AB Height (km) 20 0 Eye CloudSat and tropical cyclones -- So far we have intersected the eyes of 4 different tropical cyclones

Tropical Weather States

COMPARISON OF ORDINARY TO ORGANIZED CONVECTION CLOUDSAT VIEW WS3WS1

Distribution of Tropical Precipitation by Weather State

LW CRE at Surface & TOA Atmospheric Heating/Cooling Heating Cooling Heating

THE PERFECT STORM

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

Lifecycle of Tropical Convective System

Level of Neutral Buoyancy

ISCCP GLOBAL WEATHER STATES

CVS DISTRIBUTIONS FOR GLOBAL WEATHER STATES

500 MB VERTICAL VELOCITY DISTRIBUTIONS FOR GWS