Formation and Development of Diabatic Rossby Vortices in a 10-Year Climatology

摘要

A diabatic Rossby vortex (DRV) is a short-scale, diabatically dominated, moist baroclinic disturbance that forms and grows in the absence of discernible upper tropospheric forcing. The overarching goal of this work is to expand on the limited amount of DRV research by examining the general characteristics of real-world DRVs that have been identified in an automated 10-year DRV climatology. The identified 314 DRVs form preferentially over warm ocean currents. All DRVs track to the east northeast. While more DRVs form during the warm season, a larger fraction of storms that explosively deepen occur during the cold season. Composite analyses bear strong resemblance to DRV structural plots in the published literature, confirming that moisture, baroclinicity and the diabatic generation of eddy available potential energy are essential to DRV formation and development. Upon inspection of the interaction between DRVs and the dynamic tropopause (DT), nine (30%) of the 31 explosively deepened DRVs are subjectively determined (based on how the DRVs interacted with DT to bomb) to be of type A development (as defined by Petterssen and Smebye [1971], so-called bottom-up development). The remaining 22 (70%) are subjectively identified as type C development (mutual interaction of pre-existing upper and lower tropospheric disturbances, as defined by Deveson et al. [2002]).