Local-time variabilities of march equinox daytime SABER CO2 in the upper mesosphere and lower thermosphere region

Results show that daytime SABER CO2 in the upper mesosphere between latitudes 30°S and 50°N is lower in the morning than in the afternoon.

The same was found in the lower thermosphere but between latitudes 50°S and 50°N. The opposite was found in the upper mesosphere between 50°S and 30°S. These results are compared to simulations of CO2 by the Whole Atmosphere Community Climate Model-eXtended. It was found that the local-time variations of Whole Atmosphere Community Climate Model–eXtended CO2 are weaker than SABER CO2. Model diagnostics indicated that these local-time variations in the model are driven primarily (secondarily) by strong vertical (meridional) gradients in Upper Mesosphere and Lower Thermosphere CO2 volume mixing ratios and strong local-time variations in vertical (meridional) winds.