Large Scale Gravity Waves Perturbations in Mesopause Region

Wednesday, November 23, 2016

To investigate the Gravity Wave (GW) in the mid-latitude mesopause region during boreal equinox, 433 hours of continuous full diurnal cycle temperature measurements in September between 2011 and 2015. These observations are from a Na Doppler/Temperature lidar, operating at Utah State University (42°N, 112°W), are utilized to derive the climatological profiles of GW induced temperature variance, and the potential energy density (PED).

Gravity wave image
The 5 year Utah State University Na Lidar September monthly climatology of a) temperature variance and b) potential energy density (PED) of gravity waves obtained from fitting the 24-hour observations (black) and the fit for Nightly Linear Fit (NLF) (red).

As the only GW perturbations investigation based upon full diurnal cycle temperature observations, this study reveals severe GW dissipation near 90 km, where both parameters drop to their minima. To derive the precise temperature perturbations, a new tidal removal algorithm, suit for all ground based observations, is developed to distill the GW induced perturbations from the hourly lidar temperature measurements. It removes the tidal perturbations completely, thus, provides the most accurate GW perturbations for the ground based observations. This algorithm is validated by its application on the most recent mesoscale-resolving simulations results from Whole Atmosphere Community Climate Model (WACCM), along with the comparison to the true GW perturbations revealed by the zonal wavenumber removal algorithm in the model data.

Full title: Large Scale Gravity Waves perturbations in mesopause region above northern hemisphere mid-latitude during Autumnal equinox: A joint study.

Submitted to Geophysical Research Letters on November 3, 2016