Stereo observations of polar stratospheric clouds

We present the first observations of polar stratospheric clouds (PSCs) within near-infrared (NIR) satellite images by using the Multi-angle Imaging SpectroRadiometer (MISR) to stereoscopically identify clouds with altitudes above the tropopause. Rather than using the operational MISR stereo product, a tailored stereo height algorithm operating upon MISR’s most oblique viewing cameras is employed to identify PSC. Cloud top heights retrieved by this algorithm for scenes observed during the 2003 Antarctic Spring exhibit bias relative to the satellite-borne lidar, GLAS, of -0.60 ± 1.71 km for low (1 –5 km altitude) tropospheric clouds, -0.35 ± 1.48 km for high (>5 km altitude) tropospheric clouds, and 0.77 ± 1.86 km for low (<18 km altitude) stratospheric clouds. During this period, MISR captured a Sep. 30th intensification of PSC spanning over 1 million sq. km and occurring as the apparent result of synoptic scale isentropic uplift associated with a potential vorticity anomaly tied to planetary waves, but likely also strengthened by a nearby tropospheric depression.