The effect of resolution on high latitude cloud track winds produced from AVHRR imagery

Sequences of images from geostationary satellites have been used for some time to track clouds and so produce an estimate of the wind at cloud height (see/1/ and /2/). However, in the polar regions the resolution of geostationary imagery is normally too poor to allow the tracking of cloud features. Fortunately at high latitudes the swaths from the imaging instruments aboard polar orbiting satellites overlap. This means that the NOAA series of polar orbiting satellites can be used to obtain cloud track winds in the polar regions using both automatic and manual tracking. The tracking is best if full resolution (1km) imagery is used rather than 4km Global Area Coverage imagery.