25 Years of Height Resolved Cloud Motion Vector Winds from MISR Reveal Details About Atmospheric Dynamics

By utilizing multiple camera views and fast image matching algorithms to identify common features and determine feature motion, the MISR instrument on NASA’s Terra satellite has now collected more than 24 years of height-resolved cloud motion vector winds using a single, globally consistent algorithm. The MISR cloud motion vectors are reported on domains of 17.6 km x 17.6 km and referenced to stereoscopically derived heights above the earth ellipsoid, which have a nominal vertical resolution of approximately 500 m. Importantly, from the standpoint of working with such a long-term dataset, the stereo height assignments and wind retrievals are largely insensitive to instrument calibration changes. Comparisons have been made with other wind datasets, including geostationary atmospheric motion vectors, scatterometer ocean surface winds, and reanalysis model winds. These all demonstrate the quality and utility of the MISR cloud motion vector product.

We will further describe insights gained into the global wind system provided by this unique dataset. These include visualizations of the zonal mean zonal winds, the Hadley circulation and accompanying seasonal shifts in the location of the intertropical convergence zone (ITCZ). MISR cloud motion vectors also provide new perspectives on the Madden-Julian Oscillation (MJO) and the structure of the El Niño Southern Oscillation (ENSO).