Development of a land surface heating index—based method to locate regions of potential mesoscale circulation formation

摘要

A new method is developed to create a land surface heating index (HI) that has the potential to identify preferred source regions of convective initiation (CI) on a daily basis. The method employs remotely sensed land surface characteristics of vegetation and soil moisture, as well as GOES-derived insolation, to develop the HI. Strong gradients in land surface heating can lead to the development of mesoscale circulations, resembling inland sea breezes, which under synoptically calm conditions may lead to the development of CI. By using the proposed HI to locate areas of strong differential surface heating, the source regions of these circulations may be identified hours before any convection forms. The HI has many advantages over most current methods of CI nowcasting, because it is not dependent upon the extrapolation of observed radar and satellite trends, nor does it rely upon complex numerical weather prediction modeling. Also, by incorporating a variety of high-resolution data fields, it has the ability to mitigate some of the drawbacks of existing remotely sensed land surface products. The goal of this paper is to describe the development of the method, with the application and verification of the procedures to follow in a subsequent study.