MISR & CLOUD RADAR CLOUD HEIGHTS COMPARISON

OVER THE NORTH SLOPE OF ALASKA ARM SITE

The filled circles indicate the most probable values for the MISR stereo cloud heights and cloud radar cloud heights. The 10% and 90% cloud height quartile values for each instrument occur at the endpoints of the plotted lines. The MISR cloud heights come from a 10 km2 box centered on the NSA site (1.1 km resolution regridded to 275 m) and the cloud radar cloud heights come from a 30-minute time window centered on the estimated time of the MISR overpass. The cloud radar data are at a 10-second time resolution. While the most probable values for the two respective cloud heights don't always closely agree, for six of the seven cases, the MISR and cloud radar cloud heights occur within each other's 10% to 90% quartile ranges. This general agreement is subjectively supported by the larger-scale spatial (MISR) and temporal (cloud radar) variability seen in their respective data. The one case that shows clear disagreement occurs on July 7. On this day, the cloud radar detected three separate broken cloud layers. Large changes in the top cloud height occurred throughout the day. It is difficult for MISR to perform a robust stereo reference in such a situation.