As they propagate through the middle atmosphere, gravity waves interact with other waves, tides, and mean winds. These waves are primarily generated in the troposphere and propagate upward in the atmosphere. Inertial gravity (or buoyancy) waves, with periods from several minutes to several hours and vertical wavelengths on order of kilometers, have been recognized as a major contribution to the general circulation of the middle atmosphere since the 1970s ( Houghton 1978). Investigation of the mesosphere has been prompted by the fact that the region is maintained far from radiative equilibrium by dynamic and chemical heating effects ( Andrews et al. The results are discussed in terms of current lidar measurements and proposed measurements at high-latitude sites. While during winter at midday the 3.5-m system yields biases in their heat flux measurements that are less than 10% of the geophysical value, during summer at midday all of the systems yield flux biases that are greater than the geophysical value of the heat flux. During winter, at night, the three telescope systems yield biases in their heat flux measurements that are less than 10% of the reported value of the heat flux and during summer, at night, the 1.8- and 3.5-m systems yield biases in their heat flux measurements that are less than 10% of the geophysical value.

It is also found that the biases vary from −4 × 10 −3 K m s −1 for wintertime measurements at night with a 3.5-m telescope to −61 K m s −1 for summertime measurements at midday with a 1-m telescope. A cross-correlation coefficient of 2%–7% between the lidar wind and temperature estimates is found.

The expected biases in vertical heat flux measurements at a resolution of 480 m and 150 s are determined and compared to Gardner and Yang’s reported geophysical values of 2.3 K m s −1. The CSU lidar measurements are scaled, based on a 35-cm-diameter receiver telescope, to the use of large-aperture telescopes (i.e., 1-, 1.8-, and 3.5-m diameters). The authors use data from the Colorado State University (CSU) sodium Doppler wind-temperature lidar, acquired at a midlatitude site, to define the statistics of the lidar measurements in different seasons under both daytime and nighttime conditions. A statistical study is presented of the errors in sodium Doppler lidar measurements of wind and temperature in the mesosphere that arise from the statistics of the photon-counting process that is inherent in the technique.

Maui doppler