A diagnostic method for computing the surface wind from the geostrophic wind including the effects of baroclinity

A diagnostic procedure to compute the surface wind from the geostrophic wind, including the effects of baroclinity, is designed and tested. Expressions are derived to calculate the similarity functions A and B for use when only the surface geostrophic wind V sub(g) sub(0) and its vertical derivative delta V sub(g) / delta z are known (i.e., no atmospheric boundary layer winds are available). The cross-isobaric angle of the surface wind has a maximum for delta = 122 deg and a minimum for delta = 300 deg, where delta is the angle counterclockwise from V sub(g) sub(0) to delta V sub(g) / delta z. The surface wind speed is highest for delta = 30 deg and lowest for delta = 210 deg. The results are compared with observations, and the agreement is good.