The industrious grad student realizes, as nice as approximations are, that the truth measurement must be lidar. There happens to be a Micro Pulse Lidar at Goddard, which shows several faint contrails between 11 km and 12 km prior to 1805z, followed by the cirrus over DC in the Dec 22 MODIS image, which was between 8 km and 10 km.
Posted by Ray Rogers at December 24, 2005 11:31 PM