A NOTE COMPARING l-KM VERTICAL WIND SHEARS DERIVED FROM SIMULTANEOUS AN/GMD-IA & AN/GMD-2 WINDS-ALOFT OBSERVATIONS

摘要

Winds-aloft observations that were taken simultaneously by the AN/GMD-1A and AN/GMD-2 rawin sets during field trials of the new AN/GMD-2 at Andrews AFB, Maryland are analyzed and compared. For wind-speed differences for approximately one kilometer of ascent (actually three minutes) equal to and greater than 20 mps as observed by the GMD-2, the distribution of the differences as observed by the GMD-1A is presented. The maximum wind differences for the positive shear (wind increasing with height) and the negative shear (wind decreasing with height) as observed by the GMD-l A are compared with the simul¬taneous differences reported by the GMD-2. These latter differences give the approximate true shears. Comparison of the two sets of verti¬cal wind shears (wind-speed differences) makes it possible to obtain a quantitative estimate of the exaggeration in the vertical wind shears in¬dicated by operational GMD-1A soundings.