NO<sub>2</sub> vertical profiles and column densities from MAX-DOAS measurements in Mexico City

<p>We present a new numerical code, Mexican MAX-DOAS Fit (MMF), developed to retrieve profiles of different trace gases from the network of MAX-DOAS instruments operated in Mexico City. MMF uses differential slant column densities (dSCDs) retrieved with the QDOAS <span class="cit"...

Full description

Bibliographic Details
Main Authors: M. M. Friedrich, C. Rivera, W. Stremme, Z. Ojeda, J. Arellano, A. Bezanilla, J. A. García-Reynoso, M. Grutter
Format: Article
Language:English
Published: Copernicus Publications 2019-05-01
Series:Atmospheric Measurement Techniques
Online Access:https://www.atmos-meas-tech.net/12/2545/2019/amt-12-2545-2019.pdf
id doaj-9da9753d72404b11994151f332dc1958
record_format Article
spelling doaj-9da9753d72404b11994151f332dc19582020-11-24T21:25:47ZengCopernicus PublicationsAtmospheric Measurement Techniques1867-13811867-85482019-05-01122545256510.5194/amt-12-2545-2019NO<sub>2</sub> vertical profiles and column densities from MAX-DOAS measurements in Mexico CityM. M. Friedrich0M. M. Friedrich1C. Rivera2C. Rivera3W. Stremme4Z. Ojeda5J. Arellano6A. Bezanilla7J. A. García-Reynoso8M. Grutter9Centro de Ciencias de la Atmósfera, Universidad Nacional Autónoma de México, Mexico City, MexicoBelgian Institute for Space Aeronomie (BIRA-IASB), Brussels, BelgiumCentro de Ciencias de la Atmósfera, Universidad Nacional Autónoma de México, Mexico City, MexicoFacultad de Química, Universidad Nacional Autónoma de México, Mexico City, MexicoCentro de Ciencias de la Atmósfera, Universidad Nacional Autónoma de México, Mexico City, MexicoCentro de Ciencias de la Atmósfera, Universidad Nacional Autónoma de México, Mexico City, MexicoCentro de Ciencias de la Atmósfera, Universidad Nacional Autónoma de México, Mexico City, MexicoCentro de Ciencias de la Atmósfera, Universidad Nacional Autónoma de México, Mexico City, MexicoCentro de Ciencias de la Atmósfera, Universidad Nacional Autónoma de México, Mexico City, MexicoCentro de Ciencias de la Atmósfera, Universidad Nacional Autónoma de México, Mexico City, Mexico<p>We present a new numerical code, Mexican MAX-DOAS Fit (MMF), developed to retrieve profiles of different trace gases from the network of MAX-DOAS instruments operated in Mexico City. MMF uses differential slant column densities (dSCDs) retrieved with the QDOAS <span class="cit" id="xref_paren.1">(<a href="#bib1.bibx9">Danckaert et al.</a>, <a href="#bib1.bibx9">2013</a>)</span> software. The retrieval is comprised of two steps, an aerosol retrieval and a trace gas retrieval that uses the retrieved aerosol profile in the forward model for the trace gas. For forward model simulations, VLIDORT is used <span class="cit" id="xref_paren.2">(e.g., <a href="#bib1.bibx44">Spurr et al.</a>, <a href="#bib1.bibx44">2001</a>; <a href="#bib1.bibx42">Spurr</a>, <a href="#bib1.bibx42">2006</a>, <a href="#bib1.bibx43">2013</a>)</span>. Both steps use constrained least-square fitting, but the aerosol retrieval uses Tikhonov regularization and the trace gas retrieval optimal estimation. Aerosol optical depth and scattering properties from the AERONET database, averaged ceilometer data, WRF-Chem model data, and temperature and pressure sounding data are used for different steps in the retrieval chain.</p> <p>The MMF code was applied to retrieve <span class="inline-formula">NO<sub>2</sub></span> profiles with 2 degrees of freedom (DOF&thinsp;<span class="inline-formula">=</span>&thinsp;2) from spectra of the MAX-DOAS instrument located at the Universidad Nacional Autónoma de México (UNAM) campus. We describe the full error analysis of the retrievals and include a sensitivity exercise to quantify the contribution of the uncertainties in the aerosol extinction profiles to the total error. A data set comprised of measurements from January 2015 to July 2016 was processed and the results compared to independent surface measurements. We concentrate on the analysis of four single days and additionally present diurnal and annual variabilities from averaging the 1.5 years of data. The total error, depending on the exact counting, is 14&thinsp;%–20&thinsp;% and this work provides new and relevant information about <span class="inline-formula">NO<sub>2</sub></span> in the boundary layer of Mexico City.</p>https://www.atmos-meas-tech.net/12/2545/2019/amt-12-2545-2019.pdf
collection DOAJ
language English
format Article
sources DOAJ
author M. M. Friedrich
M. M. Friedrich
C. Rivera
C. Rivera
W. Stremme
Z. Ojeda
J. Arellano
A. Bezanilla
J. A. García-Reynoso
M. Grutter
spellingShingle M. M. Friedrich
M. M. Friedrich
C. Rivera
C. Rivera
W. Stremme
Z. Ojeda
J. Arellano
A. Bezanilla
J. A. García-Reynoso
M. Grutter
NO<sub>2</sub> vertical profiles and column densities from MAX-DOAS measurements in Mexico City
Atmospheric Measurement Techniques
author_facet M. M. Friedrich
M. M. Friedrich
C. Rivera
C. Rivera
W. Stremme
Z. Ojeda
J. Arellano
A. Bezanilla
J. A. García-Reynoso
M. Grutter
author_sort M. M. Friedrich
title NO<sub>2</sub> vertical profiles and column densities from MAX-DOAS measurements in Mexico City
title_short NO<sub>2</sub> vertical profiles and column densities from MAX-DOAS measurements in Mexico City
title_full NO<sub>2</sub> vertical profiles and column densities from MAX-DOAS measurements in Mexico City
title_fullStr NO<sub>2</sub> vertical profiles and column densities from MAX-DOAS measurements in Mexico City
title_full_unstemmed NO<sub>2</sub> vertical profiles and column densities from MAX-DOAS measurements in Mexico City
title_sort no<sub>2</sub> vertical profiles and column densities from max-doas measurements in mexico city
publisher Copernicus Publications
series Atmospheric Measurement Techniques
issn 1867-1381
1867-8548
publishDate 2019-05-01
description <p>We present a new numerical code, Mexican MAX-DOAS Fit (MMF), developed to retrieve profiles of different trace gases from the network of MAX-DOAS instruments operated in Mexico City. MMF uses differential slant column densities (dSCDs) retrieved with the QDOAS <span class="cit" id="xref_paren.1">(<a href="#bib1.bibx9">Danckaert et al.</a>, <a href="#bib1.bibx9">2013</a>)</span> software. The retrieval is comprised of two steps, an aerosol retrieval and a trace gas retrieval that uses the retrieved aerosol profile in the forward model for the trace gas. For forward model simulations, VLIDORT is used <span class="cit" id="xref_paren.2">(e.g., <a href="#bib1.bibx44">Spurr et al.</a>, <a href="#bib1.bibx44">2001</a>; <a href="#bib1.bibx42">Spurr</a>, <a href="#bib1.bibx42">2006</a>, <a href="#bib1.bibx43">2013</a>)</span>. Both steps use constrained least-square fitting, but the aerosol retrieval uses Tikhonov regularization and the trace gas retrieval optimal estimation. Aerosol optical depth and scattering properties from the AERONET database, averaged ceilometer data, WRF-Chem model data, and temperature and pressure sounding data are used for different steps in the retrieval chain.</p> <p>The MMF code was applied to retrieve <span class="inline-formula">NO<sub>2</sub></span> profiles with 2 degrees of freedom (DOF&thinsp;<span class="inline-formula">=</span>&thinsp;2) from spectra of the MAX-DOAS instrument located at the Universidad Nacional Autónoma de México (UNAM) campus. We describe the full error analysis of the retrievals and include a sensitivity exercise to quantify the contribution of the uncertainties in the aerosol extinction profiles to the total error. A data set comprised of measurements from January 2015 to July 2016 was processed and the results compared to independent surface measurements. We concentrate on the analysis of four single days and additionally present diurnal and annual variabilities from averaging the 1.5 years of data. The total error, depending on the exact counting, is 14&thinsp;%–20&thinsp;% and this work provides new and relevant information about <span class="inline-formula">NO<sub>2</sub></span> in the boundary layer of Mexico City.</p>
url https://www.atmos-meas-tech.net/12/2545/2019/amt-12-2545-2019.pdf
work_keys_str_mv AT mmfriedrich nosub2subverticalprofilesandcolumndensitiesfrommaxdoasmeasurementsinmexicocity
AT mmfriedrich nosub2subverticalprofilesandcolumndensitiesfrommaxdoasmeasurementsinmexicocity
AT crivera nosub2subverticalprofilesandcolumndensitiesfrommaxdoasmeasurementsinmexicocity
AT crivera nosub2subverticalprofilesandcolumndensitiesfrommaxdoasmeasurementsinmexicocity
AT wstremme nosub2subverticalprofilesandcolumndensitiesfrommaxdoasmeasurementsinmexicocity
AT zojeda nosub2subverticalprofilesandcolumndensitiesfrommaxdoasmeasurementsinmexicocity
AT jarellano nosub2subverticalprofilesandcolumndensitiesfrommaxdoasmeasurementsinmexicocity
AT abezanilla nosub2subverticalprofilesandcolumndensitiesfrommaxdoasmeasurementsinmexicocity
AT jagarciareynoso nosub2subverticalprofilesandcolumndensitiesfrommaxdoasmeasurementsinmexicocity
AT mgrutter nosub2subverticalprofilesandcolumndensitiesfrommaxdoasmeasurementsinmexicocity
_version_ 1725982850127233024