Title:
Influence of irregular temperature variations caused by gravity waves on the infrared radiative cooling/ heating of the mesosphere/lower thermosphere
Principial investigator:
Prof. Dr. Adalbert W. A. Pauldrach
Ludwig-Maximilians-Universität
Institut für Astronomie und Astrophysik
Scheinerstraße 1
81679 München
uh10107@
usm.lmu.de
Summary:
The Mesosphere and lower thermosphere region (MLT) is the gateway between the Earth’s environment and space. It is highly sensitive both to variations of the solar input and the impact from the lower atmosphere. Modeling the reaction of the MLT at various time scales to the solar variability requires correct accounting for the infrared radiative cooling/heating of the MLT in the molecular ro-vibrational bands of trace gases. We propose a novel study to investigate radiative cooling/heating effects in the MLT due to small-scale irregular temperature fluctuations caused by gravity waves. These persistent fluctuations are not resolved by modern general circulation models, but their effect on the radiative driving of the MLT is significant. We aim to develop a statistical model of gravity wave-induced variations and apply it to large-scale temperature profiles corresponding to different latitudes and seasons. For the first time, global distributions of the cooling/heating rate errors associated with the neglect of the irregular temperature structures in the infrared radiative calculations will be compiled. These distributions will be applied to develop a parameterization of the effect for implementation in general circulation models.