Comparison of Na Doppler lidar and MF radar measurements of meridional winds in the mesosphere above Urbana, IL

Simultaneous medium frequency (MF) radar and Na Doppler lidar measurements of meridional winds in the mesosphere (84-96 km) were collected at Urbana, IL in September and October, 1996. Comparisons on time scales of 1 h and longer and with height resolution of 3 km show that the two instruments measure winds that agree to within tolerances established by statistical estimation errors at night. but reveal large differences that cannot be explained by estimation errors in the daytime. After removing the altitude-independent component of both data sets, the wind estimates are shown to agree to within expectations based on measurement uncertainty at all times of the day. The most likely explanation for differences between the two data sets is determined to be undetected/uncorrected wavelength shifts in the lid ar, which would introduce offsets into the measured winds at all altitudes. (C) 2001 Elsevier Science Ltd. All rights reserved.