Extended Abstract (68K)4B.2
Spurious divergence within objective analyses with application to TOGA COARE heat and moisture budgets
Patrick T. Haertel, Colorado State University, Ft Collins, CO
When applied to pseudo-observations of non-divergent horizontal winds, objective-analysis techniques often produce wind fields that have divergence. Examples of such spurious divergence will be presented for several objective-analysis techniques and a variety of input wind fields.
Patterns of spurious divergence are sensitive to the geometries of both the observation points and the wind field being observed. Since the latter in general varies with respect to height, so does spurious divergence, and techniques to mass-balance divergence profiles generally over-correct for spurious divergence at some levels while under-correcting at other levels.
Spurious divergence is evident in gridded analyses of TOGA COARE wind observations. It is highly correlated with budget-derived precipitation estimates supporting the idea that it is causing errors in such estimates. The extent to which spurious divergence impacts TOGA COARE heat and moisture budgets as a whole will be discussed, as will techniques for minimizing its effects.
Session 4B, Convection III (Parallel with Sessions 4A, 4C, & 4D)
Tuesday, 30 April 2002, 8:30 AM-10:30 AM
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