HCl and ClO profiles inside the Antarctic vortex as observed by SMILES in November 2009: comparisons with MLS and ACE-FTS instruments
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 p...
| Main Authors: | , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2013-11-01
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| Series: | Atmospheric Measurement Techniques |
| Online Access: | http://www.atmos-meas-tech.net/6/3099/2013/amt-6-3099-2013.pdf |
| Summary: | 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 450 K and 500 K 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 (Cl<sub>y</sub>),
defined as Cl<sub>y</sub> ≃ HCl + ClO + chlorine nitrate (ClONO<sub>2</sub>), 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-à-vis the partitioning of
Cl<sub>y</sub>, 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 575 K 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
700 K 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 500 K and 650 K with
the ClO values less than 0.2 ppbv. ClONO<sub>2</sub> values as measured by ACE-FTS
also reveal 0.2 ppbv at 475–500 K level, resulting in the HCl / Cl<sub>y</sub> ratios of
0.91–0.95. The HCl / Cl<sub>y</sub> ratios derived from each retrieval
agree to within −5 to 8 % with regard to their averages. The high HCl values
and HCl / Cl<sub>y</sub> ratios observed by the three instruments in the lower
stratospheric Antarctic vortex are consistent with previous observations in
late Austral spring. |
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| ISSN: | 1867-1381 1867-8548 |