| Session Details | |
| Section | AS - Atmospheric Sciences |
| Session Title | Hydroxyl Layer on Earth and Other Planets |
| Main Convener | Dr. Mykhaylo Grygalashvyly (Leibniz-Institute of Atmospheric Physics, Germany) |
| Co-convener(s) | Prof. William Ward (University of New Brunswick, Canada) Dr. Grandhi Kishore Kumar (Research Institute for Sustainable Humanosphere (RISH), Japan) Prof. Orhan Sen (Istanbul Technical University (ITU) Faculty of Aeronautics and Astronautics, Turkey) |
| Session Description | The airglow measurements in the Meinel band of excited hydroxyl is a tool extensively used to infer temperatures at mesopause height and information about dynamical processes, such as gravity waves, planetary waves, and tides. Moreover, the observation of emission from OH* Meinel bands is used to determine atomic oxygen, ozone, and atomic hydrogen which are very difficult to measure by other methods, and, in perspective, can be used to retrieve the chemical heating rate from the most significant exothermic reaction in the mesopause. A number of investigations are focused on temperature trends obtained from measurements of the relative intensities of two lines in one of the vibrational-rotational bands. Recently, OH* Meinel band emissions were detected on Mars and Venus that give rise new interest to OH*- layers. In spite of large application, less attention was devoted to parameters of the layer such as thickness, altitude, and number density. Concerning the OH*-layer and its behavior a number of questions arise. How does the altitude of OH* change? How does the intensity (number density) of OH* change? Which variations in temperature corresponds to OH* variations? How does the variation in OH* depend on the Lyman-alpha variation? How much of the variation is dependent on chemistry, dynamics and the Lyman-alpha, respectively? How does the OH* variation depend on the vibrational number? What is the relative behavior for OH* with different vibrational numbers? What is the dependence between the height and intensity of the emission (number density) of the layer? These questions can be asked about the variation of height, number density, thickness, and corresponding temperature in the framework of seasonal-latitudinal, short-term, and long-term variability. The questions on formation-relaxation processes of OH* are represent an additional field related to hydroxyl layer. In frame of the session we intend to collect some theoretical, modelling and experimental works on these questions. |