Global distributions of nitric acid from IASI/MetOP measurements
This paper presents the first global distributions of HNO3 total columns acquired by the Infrared Atmospheric Sounding Interferometer (IASI) instrument, launched onboard the MetOp platform in October 2006. IASI is an infrared nadir-looking Fourier transform spectrometer providing atmospheric radianc...
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ftunivbruxelles:oai:dipot.ulb.ac.be:2013/75240 2023-05-15T14:02:22+02:00 Global distributions of nitric acid from IASI/MetOP measurements Wespes, Catherine Hurtmans, Daniel Clerbaux, Cathy Santee, M.L. Martin, R.V. Coheur, Pierre 2009 1 full-text file(s): application/pdf http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/75240 https://dipot.ulb.ac.be/dspace/bitstream/2013/75240/1/wespes_acp_2009.pdf en eng uri/info:scp/71149107086 https://dipot.ulb.ac.be/dspace/bitstream/2013/75240/1/wespes_acp_2009.pdf http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/75240 1 full-text file(s): info:eu-repo/semantics/closedAccess Atmospheric chemistry and physics, 9 Chimie Spectroscopie [électromagnétisme optique acoustique] Télédétection Aéronomie Environnement et pollution info:eu-repo/semantics/article info:ulb-repo/semantics/articlePeerReview info:ulb-repo/semantics/openurl/article 2009 ftunivbruxelles 2022-06-12T22:05:25Z This paper presents the first global distributions of HNO3 total columns acquired by the Infrared Atmospheric Sounding Interferometer (IASI) instrument, launched onboard the MetOp platform in October 2006. IASI is an infrared nadir-looking Fourier transform spectrometer providing atmospheric radiance spectra at 0.5 cm?1 spectral resolution, from which temperature and infrared absorbing gas concentration profiles are retrieved with global Earth coverage twice a day. A first analysis of the IASI measurements in terms of information content demonstrates the possibility of retrieving a total column for HNO3 at all latitudes with a maximal sensitivity in the middle stratosphere. The retrievals are performed from IASI spectra in the atmospheric window using a fast radiative transfer model and inversion software (FORLI) relying on the Optimal Estimation Method. The operational processing of HNO3 total columns is achieved since March 2008. We show that FORLI-HNO3 performs well at all latitudes (RMS of the spectral residuals around 2.3×10?6 W/m2 srm?1) and provides HNO3 total columns with on average statistical errors of about 12%, reaching the threshold value of 32% at the equatorial belt. The global distributions of the retrieved total columns for one year (from March 2008 to February 2009) are presented and discussed with emphasis given to seasonal and interhemispheric variations. Local seasonal variations at 6 specific locations are also described and discussed in comparison with MLS volume mixing ratios at 46.5 hPa. The seasonal cycle observedin Polar regions is highlighted, with maxima observed in fallwinter and minima during spring-summer. The denitrification inside the Antarctic polar vortex during winter is clearly revealed with unprecedented horizontal resolution: HNO 3 columns decreasing down to about 1×cm?2 are observed, which is consistent with the lower values of temperature observed between 50 and 15 hPa (∼20-25 km) and the resulting formation and sedimentation of polar stratospheric clouds. During the ... Article in Journal/Newspaper Antarc* Antarctic DI-fusion : dépôt institutionnel de l'Université libre de Bruxelles (ULB) Antarctic The Antarctic |
institution |
Open Polar |
collection |
DI-fusion : dépôt institutionnel de l'Université libre de Bruxelles (ULB) |
op_collection_id |
ftunivbruxelles |
language |
English |
topic |
Chimie Spectroscopie [électromagnétisme optique acoustique] Télédétection Aéronomie Environnement et pollution |
spellingShingle |
Chimie Spectroscopie [électromagnétisme optique acoustique] Télédétection Aéronomie Environnement et pollution Wespes, Catherine Hurtmans, Daniel Clerbaux, Cathy Santee, M.L. Martin, R.V. Coheur, Pierre Global distributions of nitric acid from IASI/MetOP measurements |
topic_facet |
Chimie Spectroscopie [électromagnétisme optique acoustique] Télédétection Aéronomie Environnement et pollution |
description |
This paper presents the first global distributions of HNO3 total columns acquired by the Infrared Atmospheric Sounding Interferometer (IASI) instrument, launched onboard the MetOp platform in October 2006. IASI is an infrared nadir-looking Fourier transform spectrometer providing atmospheric radiance spectra at 0.5 cm?1 spectral resolution, from which temperature and infrared absorbing gas concentration profiles are retrieved with global Earth coverage twice a day. A first analysis of the IASI measurements in terms of information content demonstrates the possibility of retrieving a total column for HNO3 at all latitudes with a maximal sensitivity in the middle stratosphere. The retrievals are performed from IASI spectra in the atmospheric window using a fast radiative transfer model and inversion software (FORLI) relying on the Optimal Estimation Method. The operational processing of HNO3 total columns is achieved since March 2008. We show that FORLI-HNO3 performs well at all latitudes (RMS of the spectral residuals around 2.3×10?6 W/m2 srm?1) and provides HNO3 total columns with on average statistical errors of about 12%, reaching the threshold value of 32% at the equatorial belt. The global distributions of the retrieved total columns for one year (from March 2008 to February 2009) are presented and discussed with emphasis given to seasonal and interhemispheric variations. Local seasonal variations at 6 specific locations are also described and discussed in comparison with MLS volume mixing ratios at 46.5 hPa. The seasonal cycle observedin Polar regions is highlighted, with maxima observed in fallwinter and minima during spring-summer. The denitrification inside the Antarctic polar vortex during winter is clearly revealed with unprecedented horizontal resolution: HNO 3 columns decreasing down to about 1×cm?2 are observed, which is consistent with the lower values of temperature observed between 50 and 15 hPa (∼20-25 km) and the resulting formation and sedimentation of polar stratospheric clouds. During the ... |
format |
Article in Journal/Newspaper |
author |
Wespes, Catherine Hurtmans, Daniel Clerbaux, Cathy Santee, M.L. Martin, R.V. Coheur, Pierre |
author_facet |
Wespes, Catherine Hurtmans, Daniel Clerbaux, Cathy Santee, M.L. Martin, R.V. Coheur, Pierre |
author_sort |
Wespes, Catherine |
title |
Global distributions of nitric acid from IASI/MetOP measurements |
title_short |
Global distributions of nitric acid from IASI/MetOP measurements |
title_full |
Global distributions of nitric acid from IASI/MetOP measurements |
title_fullStr |
Global distributions of nitric acid from IASI/MetOP measurements |
title_full_unstemmed |
Global distributions of nitric acid from IASI/MetOP measurements |
title_sort |
global distributions of nitric acid from iasi/metop measurements |
publishDate |
2009 |
url |
http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/75240 https://dipot.ulb.ac.be/dspace/bitstream/2013/75240/1/wespes_acp_2009.pdf |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
Atmospheric chemistry and physics, 9 |
op_relation |
uri/info:scp/71149107086 https://dipot.ulb.ac.be/dspace/bitstream/2013/75240/1/wespes_acp_2009.pdf http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/75240 |
op_rights |
1 full-text file(s): info:eu-repo/semantics/closedAccess |
_version_ |
1766272597952036864 |