HCI and CIO Profiles Inside the Antarctic Vortex as Observed by Smiles in November 2009: Comparisons with MLS and ACE-FTS Instruments

• Published in: Atmospheric Measurement Techniques
• Main Authors: Sugita, T., Kasai, Y., Terao, Y., Hayashida, S., Manney, G. L., Daffer, W. H., Sagawa, H., Suzuki, M., Shiotani, M., Walker, K. A., Boone, C. D., Bernath, P. F.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: ODU Digital Commons 2013
• Subjects: Microwave limb sounder; Fourier transform spectrometer; Stratospheric polar vortex; Large (CO)-C-13 deficit; Ozone hole chemistry; Mean age; Chlorine reservoirs; Arctic vortex; Validation; Model; Atmospheric Sciences; Chemistry; Arctic; Antarctic; The Antarctic; Austral; Antarc*
• Online Access: https://digitalcommons.odu.edu/chemistry_fac_pubs/28; https://doi.org/10.5194/amt-6-3099-2013; https://digitalcommons.odu.edu/context/chemistry_fac_pubs/article/1034/viewcontent/Sugita_2013_HCl_and_ClO_profiles.pdf

We present vertical profiles of hydrogen chloride (HCl) and chlorine monoxide (ClO) as observed by the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on the International Space Station (ISS) inside the Antarctic vortex on 19-24 November 2009. The SMILES HCl value reveals 2.8-3.1 ppbv between 450K and 500K levels in potential temperature (PT). The high value of HCl is highlighted since it is suggested that HCl is a main component of the total inorganic chlorine Cly, defined as Cly similar or equal to HCl + ClO + chlorine nitrate ClONO2, inside the Antarctic vortex in spring, owing to low ozone values. To confirm the quality of two SMILES level 2 (L2) data products provided by the Japan Aerospace Exploration Agency (JAXA) and Japan's National Institute of Information and Communications Technology (NICT), vis-a-vis the partitioning of Cly, comparisons are made using other satellite data from the Aura Microwave Limb Sounder (MLS) and Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS). HCl values from the SMILES NICT L2 product agree to within 10% (0.3 ppbv) with the MLS HCl data between 450 and 575K levels in PT and with the ACE-FTS HCl data between 425 and 575 K. The SMILES JAXA L2 product is 10 to 20% (0.2-0.5 ppbv) lower than that from MLS between 400 and 700K and from ACE-FTS between 500 and 700 K. For ClO in daytime, the difference between SMILES (JAXA and NICT) and MLS is less than ±0.05 ppbv (100 %) between 500K and 650K with the ClO values less than 0.2 ppbv. ClONO2 values as measured by ACE-FTS also reveal 0.2 ppbv at 475-500K level, resulting in the HCl/Cly ratios of 0.91-0.95. The HCl/Cly ratios derived from each retrieval agree to within -5 to 8% with regard to their averages. The high HCl values and HCl/Cly ratios observed by the three instruments in the lower stratospheric Antarctic vortex are consistent with previous observations in late Austral spring.