The importance of the horizontal distribution of heating during extratropical cyclone development

Diagnostic and modeling results reveal that atmospheric heating typically acts to intensify extratropical cyclones. In addition, both the Petterssen-Sutcliffe and Zwack-Okossi development equations reveal that this relationship depends on the proportionality that exists between surface geostrophic vorticity tendency and the negative of the horizontal Laplacian of atmospheric heating. Because of this Laplacian relationship, the impact of a heating field with a given magnitude and vertical distribution depends on its horizontal distribution. This paper will show how horizontal heating distributions that differ by relatively small amounts over their entire extent can yield vorticity tendency responses that could contribute to either development or decay of an underlying cyclone.