Technical note: Evaluation of profile retrievals of aerosols and trace gases for MAX-DOAS measurements under different aerosol scenarios based on radiative transfer simulations
<p>Ground-based Multi-AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) is a state-of-the-art remote sensing technique for deriving vertical profiles of trace gases and aerosols. However, MAX-DOAS profile inversions under aerosol pollution scenarios are challenging because of the co...
| Main Authors: | , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2021-08-01
|
| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/21/12867/2021/acp-21-12867-2021.pdf |
| _version_ | 1818722658194292736 |
|---|---|
| author | X. Tian X. Tian Y. Wang Y. Wang S. Beirle P. Xie P. Xie P. Xie P. Xie T. Wagner J. Xu A. Li S. Dörner B. Ren B. Ren X. Li |
| author_facet | X. Tian X. Tian Y. Wang Y. Wang S. Beirle P. Xie P. Xie P. Xie P. Xie T. Wagner J. Xu A. Li S. Dörner B. Ren B. Ren X. Li |
| author_sort | X. Tian |
| collection | DOAJ |
| description | <p>Ground-based Multi-AXis Differential Optical Absorption
Spectroscopy (MAX-DOAS) is a state-of-the-art remote sensing technique for
deriving vertical profiles of trace gases and aerosols. However, MAX-DOAS
profile inversions under aerosol pollution scenarios are challenging because
of the complex radiative transfer and limited information content of the
measurements. In this study, the performances of two inversion algorithms
were evaluated for various aerosol pollution scenarios based on synthetic
slant column densities (SCDs) derived from radiative transfer simulations.
Compared to previous studies, in our study, much larger ranges of aerosol optical depth (AOD) and
NO<span class="inline-formula"><sub>2</sub></span> vertical column densities (VCDs) are covered. One inversion algorithm is based on optimal
estimation; the other uses a parameterized approach. In this analysis, three
types of profile shapes for aerosols and NO<span class="inline-formula"><sub>2</sub></span> were considered:
exponential, Boltzmann, and Gaussian. First, the systematic deviations of
the retrieved aerosol profiles from the input profiles were investigated.
For most cases, the AODs of the retrieved profiles were found to be
systematically lower than the input values, and the deviations increased
with increasing AOD. In particular for the optimal estimation algorithm and for
high AOD, these findings are consistent with the results in previous studies.
The assumed single scattering albedo (SSA) and asymmetry parameter (AP) have a systematic
influence on the aerosol retrieval. However, for most cases the influence of
the assumed SSA and AP on the retrieval results are rather small (compared
to other uncertainties). For the optimal estimation algorithm, the agreement
with the input values can be improved by optimizing the covariance matrix of
the a priori uncertainties. Second, the aerosol effects on the NO<span class="inline-formula"><sub>2</sub></span> profile
retrieval were tested. Here, especially for the optimal estimation
algorithm, a systematic dependence on the NO<span class="inline-formula"><sub>2</sub></span> VCD was found, with a
strong relative overestimation of the retrieved results for low NO<span class="inline-formula"><sub>2</sub></span>
VCDs and an underestimation for high NO<span class="inline-formula"><sub>2</sub></span> VCDs. In contrast, the
dependence on the aerosol profiles was found to be rather low.
Interestingly, the results for both investigated wavelengths (360 and 477 nm) were found to be rather similar, indicating that the differences in the
radiative transfer between both wavelengths have no strong effect. In
general, both inversion schemes can retrieve<span id="page12868"/> the near-surface values of
aerosol extinction and trace gas concentrations well.</p> |
| first_indexed | 2024-12-17T20:58:07Z |
| format | Article |
| id | doaj.art-553a78d5d82e4de381366f3d5ee3428b |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-17T20:58:07Z |
| publishDate | 2021-08-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-553a78d5d82e4de381366f3d5ee3428b2022-12-21T21:32:48ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242021-08-0121128671289410.5194/acp-21-12867-2021Technical note: Evaluation of profile retrievals of aerosols and trace gases for MAX-DOAS measurements under different aerosol scenarios based on radiative transfer simulationsX. Tian0X. Tian1Y. Wang2Y. Wang3S. Beirle4P. Xie5P. Xie6P. Xie7P. Xie8T. Wagner9J. Xu10A. Li11S. Dörner12B. Ren13B. Ren14X. Li15Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, Hefei, 230601, ChinaKey Laboratory of Environmental Optical and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Science, Hefei, 230031, ChinaMax Planck Institute for Chemistry, 55128 Mainz, Germanynow at: EUMETSAT, Darmstadt, GermanyMax Planck Institute for Chemistry, 55128 Mainz, GermanyKey Laboratory of Environmental Optical and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Science, Hefei, 230031, ChinaCAS Center for Excellence in Urban Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, ChinaUniversity of Chinese Academy of Sciences, Beijing, 100049, ChinaSchool of Environmental Science and Optoelectronic Technology, University of Science and Technology of China, Hefei, 230026, ChinaMax Planck Institute for Chemistry, 55128 Mainz, GermanyKey Laboratory of Environmental Optical and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Science, Hefei, 230031, ChinaKey Laboratory of Environmental Optical and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Science, Hefei, 230031, ChinaMax Planck Institute for Chemistry, 55128 Mainz, GermanyKey Laboratory of Environmental Optical and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Science, Hefei, 230031, ChinaSchool of Environmental Science and Optoelectronic Technology, University of Science and Technology of China, Hefei, 230026, ChinaKey Laboratory of Environmental Optical and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Science, Hefei, 230031, China<p>Ground-based Multi-AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) is a state-of-the-art remote sensing technique for deriving vertical profiles of trace gases and aerosols. However, MAX-DOAS profile inversions under aerosol pollution scenarios are challenging because of the complex radiative transfer and limited information content of the measurements. In this study, the performances of two inversion algorithms were evaluated for various aerosol pollution scenarios based on synthetic slant column densities (SCDs) derived from radiative transfer simulations. Compared to previous studies, in our study, much larger ranges of aerosol optical depth (AOD) and NO<span class="inline-formula"><sub>2</sub></span> vertical column densities (VCDs) are covered. One inversion algorithm is based on optimal estimation; the other uses a parameterized approach. In this analysis, three types of profile shapes for aerosols and NO<span class="inline-formula"><sub>2</sub></span> were considered: exponential, Boltzmann, and Gaussian. First, the systematic deviations of the retrieved aerosol profiles from the input profiles were investigated. For most cases, the AODs of the retrieved profiles were found to be systematically lower than the input values, and the deviations increased with increasing AOD. In particular for the optimal estimation algorithm and for high AOD, these findings are consistent with the results in previous studies. The assumed single scattering albedo (SSA) and asymmetry parameter (AP) have a systematic influence on the aerosol retrieval. However, for most cases the influence of the assumed SSA and AP on the retrieval results are rather small (compared to other uncertainties). For the optimal estimation algorithm, the agreement with the input values can be improved by optimizing the covariance matrix of the a priori uncertainties. Second, the aerosol effects on the NO<span class="inline-formula"><sub>2</sub></span> profile retrieval were tested. Here, especially for the optimal estimation algorithm, a systematic dependence on the NO<span class="inline-formula"><sub>2</sub></span> VCD was found, with a strong relative overestimation of the retrieved results for low NO<span class="inline-formula"><sub>2</sub></span> VCDs and an underestimation for high NO<span class="inline-formula"><sub>2</sub></span> VCDs. In contrast, the dependence on the aerosol profiles was found to be rather low. Interestingly, the results for both investigated wavelengths (360 and 477 nm) were found to be rather similar, indicating that the differences in the radiative transfer between both wavelengths have no strong effect. In general, both inversion schemes can retrieve<span id="page12868"/> the near-surface values of aerosol extinction and trace gas concentrations well.</p>https://acp.copernicus.org/articles/21/12867/2021/acp-21-12867-2021.pdf |
| spellingShingle | X. Tian X. Tian Y. Wang Y. Wang S. Beirle P. Xie P. Xie P. Xie P. Xie T. Wagner J. Xu A. Li S. Dörner B. Ren B. Ren X. Li Technical note: Evaluation of profile retrievals of aerosols and trace gases for MAX-DOAS measurements under different aerosol scenarios based on radiative transfer simulations Atmospheric Chemistry and Physics |
| title | Technical note: Evaluation of profile retrievals of aerosols and trace gases for MAX-DOAS measurements under different aerosol scenarios based on radiative transfer simulations |
| title_full | Technical note: Evaluation of profile retrievals of aerosols and trace gases for MAX-DOAS measurements under different aerosol scenarios based on radiative transfer simulations |
| title_fullStr | Technical note: Evaluation of profile retrievals of aerosols and trace gases for MAX-DOAS measurements under different aerosol scenarios based on radiative transfer simulations |
| title_full_unstemmed | Technical note: Evaluation of profile retrievals of aerosols and trace gases for MAX-DOAS measurements under different aerosol scenarios based on radiative transfer simulations |
| title_short | Technical note: Evaluation of profile retrievals of aerosols and trace gases for MAX-DOAS measurements under different aerosol scenarios based on radiative transfer simulations |
| title_sort | technical note evaluation of profile retrievals of aerosols and trace gases for max doas measurements under different aerosol scenarios based on radiative transfer simulations |
| url | https://acp.copernicus.org/articles/21/12867/2021/acp-21-12867-2021.pdf |
| work_keys_str_mv | AT xtian technicalnoteevaluationofprofileretrievalsofaerosolsandtracegasesformaxdoasmeasurementsunderdifferentaerosolscenariosbasedonradiativetransfersimulations AT xtian technicalnoteevaluationofprofileretrievalsofaerosolsandtracegasesformaxdoasmeasurementsunderdifferentaerosolscenariosbasedonradiativetransfersimulations AT ywang technicalnoteevaluationofprofileretrievalsofaerosolsandtracegasesformaxdoasmeasurementsunderdifferentaerosolscenariosbasedonradiativetransfersimulations AT ywang technicalnoteevaluationofprofileretrievalsofaerosolsandtracegasesformaxdoasmeasurementsunderdifferentaerosolscenariosbasedonradiativetransfersimulations AT sbeirle technicalnoteevaluationofprofileretrievalsofaerosolsandtracegasesformaxdoasmeasurementsunderdifferentaerosolscenariosbasedonradiativetransfersimulations AT pxie technicalnoteevaluationofprofileretrievalsofaerosolsandtracegasesformaxdoasmeasurementsunderdifferentaerosolscenariosbasedonradiativetransfersimulations AT pxie technicalnoteevaluationofprofileretrievalsofaerosolsandtracegasesformaxdoasmeasurementsunderdifferentaerosolscenariosbasedonradiativetransfersimulations AT pxie technicalnoteevaluationofprofileretrievalsofaerosolsandtracegasesformaxdoasmeasurementsunderdifferentaerosolscenariosbasedonradiativetransfersimulations AT pxie technicalnoteevaluationofprofileretrievalsofaerosolsandtracegasesformaxdoasmeasurementsunderdifferentaerosolscenariosbasedonradiativetransfersimulations AT twagner technicalnoteevaluationofprofileretrievalsofaerosolsandtracegasesformaxdoasmeasurementsunderdifferentaerosolscenariosbasedonradiativetransfersimulations AT jxu technicalnoteevaluationofprofileretrievalsofaerosolsandtracegasesformaxdoasmeasurementsunderdifferentaerosolscenariosbasedonradiativetransfersimulations AT ali technicalnoteevaluationofprofileretrievalsofaerosolsandtracegasesformaxdoasmeasurementsunderdifferentaerosolscenariosbasedonradiativetransfersimulations AT sdorner technicalnoteevaluationofprofileretrievalsofaerosolsandtracegasesformaxdoasmeasurementsunderdifferentaerosolscenariosbasedonradiativetransfersimulations AT bren technicalnoteevaluationofprofileretrievalsofaerosolsandtracegasesformaxdoasmeasurementsunderdifferentaerosolscenariosbasedonradiativetransfersimulations AT bren technicalnoteevaluationofprofileretrievalsofaerosolsandtracegasesformaxdoasmeasurementsunderdifferentaerosolscenariosbasedonradiativetransfersimulations AT xli technicalnoteevaluationofprofileretrievalsofaerosolsandtracegasesformaxdoasmeasurementsunderdifferentaerosolscenariosbasedonradiativetransfersimulations |