Presentation on theme: "Dynamical processes at the storm top PAO K. WANG DEPARTMENT OF ATMOSPHERIC AND OCEANIC SCIENCES UNIVERSITY OF WISCONSIN-MADISON MADISON, WISCONSIN, USA."— Presentation transcript:
Dynamical processes at the storm top PAO K. WANG DEPARTMENT OF ATMOSPHERIC AND OCEANIC SCIENCES UNIVERSITY OF WISCONSIN-MADISON MADISON, WISCONSIN, USA RESEARCH CENTER FOR ENVIRONMENTAL CHANGES ACADEMIA SINICA TAIPEI, TAIWAN 2014-04-08 EUMETSAT CWG WORKSHOP, ZAGREB, CROATIA
collaborators Kai-Yuan Cheng Tempei Hashino Martin Setvak Maria Putsay Zdenek Charvat
Satellite observed features of storm tops The features shown at the top of a storm is the combined result of many different physical processes If we can explain the formation of these features, we can understand better the development of thunderstorms We can also use such knowledge to nowcast the storm behavior
Some storm top features recently examined Above anvil cirrus plumes Cold-U(V) Cold area (CA) Closed-in warm area (CWA) Warm-cold couplet Cold rings Warm trenches Ship waves
Basic dynamic processes of deep convection Air parcel rapidly rises from the boundary layer to the tropopause level, and often overshoot, to release the instability Part of the KE carried by the parcel is used to excite internal gravity waves (IGW) near the storm top when the parcel encounters the stable stratosphere The interaction among updraft, ambient wind, and IGW is largely responsible for most storm top features as observed by meteorological satellites.
Above anvil cirrus plumes Instability and Wave Breaking Convection-induced instability and gravity wave breaking at the storm top send H 2 O through the tropopause to enter the stratosphere. Overshooting top plumes Anvil wave breaking Wang (2007)
Implications Cbs with radial cirrus features possibly have two or more overshooting tops The IGW caused by different OTs interfere which causes the quasi-radial pattern Interference enhances wave amplitude, hence stronger CAT above the storm may be expected Above storm layer is possibly more humid than previously thought Do the presence of multiple OTs indicate a more intense storm?