Evaluation of Multiangle Imaging Spectroradiometer cloud motion vectors using NOAA radar wind profiler data

Abstract

Cloud motion vectors obtained stereoscopically by the Multiangle Imaging Spectroradiometer (MISR) are evaluated. The reference data for this assessment is taken from 23 sites in NOAA's radar wind profiler network located across the central United States. Agreement between the two data sets is appraised as a function of cloud top height, MISR wind retrieval quality estimates, and version of the stereoscopic retrieval algorithm. For “Best Winds” retrievals, the comparison between matched MISR and NOAA profiler wind components yields biases of about 1.3 m s−1 with standard deviations of 4–6 m s−1. Comparisons are better for winds retrieved close to the surface than at high altitudes. Updates to the MISR stereoscopic retrieval algorithm have improved the level of agreement over time. Tightening of MISR data quality standards has also improved agreement, but at the expense of decreasing the number of available MISR wind vector estimates.