A dynamical study of the winter mid-latitude mesopause region (80–105KM) based on initial simultaneous lidar measurements of temperature and winds over Fort Collins, CO (41N 105W) Original Research Article

In January–February, 2002, the Colorado State Na lidar was configured for nighttime simultaneous observation of temperatures, zonal and meridional winds in the mesopause region (80 and 105 km). A total of 7 nights of observation were conducted, with data length ranging between 9 hours and 12 hours per night. Winter wave activity is evident in the data, which contains regions of instability throughout the campaign. The 70 profiles of temperature, zonal and meridional wind used to derive atmospheric stability statistics are also presented, as are wind shear amplitude and altitude distributions. Our results show that large wind and wind gradients are common in the mesopause region, in agreement with a recent study based on four decades of rocket-borne chemical release measurements. Our lidar data is also used to assess the extent of convective and dynamic atmospheric stability. We report that in the time scale of one hour and vertical resolution of 2km, somewhere in the region between 80 and 105km, there is a 22% chance that the atmosphere may be dynamically unstable, with Richardson number less than 0.25, and a 4% chance that it is convectively unstable.