Variation of HO2 and HCl in MLT (mesosphere and lower thermosphere) region
Abstract
Chemical and Dynamical behavior of HO2 radical, a key atmospheric oxidant, and HCl, oxidant depleting species, has an important role for the chemistry in the mesosphere and lower thermosphere (MLT) region. There has been no observation evidence for the vertical behavior of HO2 and HCl simultaneously near the mesopause region. We retrieve vertical profile of HO2 and HCl up to about 100km with new algorithm from spectra measured using the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on the Japanese Experiment Module (JEM) of the International Space Station (ISS) between 12 October 2009 and 21 April 2010. We improved the internal consistency between vertical profile of atmospheric species, temperature/pressure, and altitude to use of "one" atmosphere for from ground to upper thermosphere from the model named GAIA (Ground-to-topside model of Atmosphere and Ionosphere for Aeronomy) for the retrieval calculation. New products are named SMILES NICT level 2 product version 3.0.0 (L2 ver. 3.0.0). The quality of the L2 ver.3.0.0 were assessed t by comparing with several model calculations. We for the first time revealed a diurnal variation of HO2 in the mesosphere and mesopause. The interesting chemical mechanism of HO2 in mesopause is explained by comparing with simple 1D model calculations by us, qualitatively. We also found the cause of latitudinal and seasonal variation of HCl in the lower thermosphere is due to various dynamical process in the MLT region, including semi-annual oscillation and intraseasonal oscillation.
- Publication:
-
42nd COSPAR Scientific Assembly
- Pub Date:
- July 2018
- Bibcode:
- 2018cosp...42E1880K