PLEASE POST


 

MMM      SEMINAR      NCAR


 

 

Observations and Analyses of Mesoscale Convective Vortices from BAMEX

 

Chris Davis, NCAR

 

 

       During the Bow-echo and MCV Experiment (BAMEX) in 2003 aircraft and surface observing facilities sampled more than 20 mesoscale convective systems or mesoscale convective vortices (MCVs) produced by such systems. In this talk, we review the motivation for and design of BAMEX, summarize briefly the events sampled and present results from an initial analysis of MCVs observed during the project. Both developing MCVs within convective systems and mature MCVs, persisting beyond the decay of convection which formed the vortex, will be discussed. Dropsondes, spaced 50-100 km apart and wind profilers allow unprecedented documentation of the vorticity and vertical motion within mature MCVs. This, in turn, allows us to answer questions about what allows mature MCVs to persist and initiates new convection within their circulations.

It appears that lower-tropospheric ascent occurs predominantly downshear from the vortex center (and descent upshear), in agreement with theory, but there are significant asymmetries in some cases that help localize subsequent rainfall. Future research opportunities presented by the combination of BAMEX data (airborne pseudo-dual-Doppler data, in situ aircraft observations, soundings, etc.) with the background operational data will also be discussed.

 

 

Thursday, April 8, 2004, 3:30 PM

Refreshments 3:15 PM

NCAR-Foothills Laboratory

3450 Mitchell Lane

Bldg 2, Rm 1001