How aerosol size matters in aerosol optical depth (AOD) assimilation and the optimization using the Ångström exponent
Satellite-based aerosol optical depth (AOD) has gained popularity as a powerful data source for calibrating aerosol models and correcting model errors through data assimilation. However, simulated airborne particle mass concentrations are not directly comparable to satellite-based AODs. For this, an...
Published in: | Atmospheric Chemistry and Physics |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2023
|
Subjects: | |
Online Access: | https://doi.org/10.5194/acp-23-1641-2023 https://doaj.org/article/41b1612c647a4016a692112cccbc8e21 |
id |
ftdoajarticles:oai:doaj.org/article:41b1612c647a4016a692112cccbc8e21 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:41b1612c647a4016a692112cccbc8e21 2023-05-15T13:06:34+02:00 How aerosol size matters in aerosol optical depth (AOD) assimilation and the optimization using the Ångström exponent J. Jin B. Henzing A. Segers 2023-01-01T00:00:00Z https://doi.org/10.5194/acp-23-1641-2023 https://doaj.org/article/41b1612c647a4016a692112cccbc8e21 EN eng Copernicus Publications https://acp.copernicus.org/articles/23/1641/2023/acp-23-1641-2023.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 doi:10.5194/acp-23-1641-2023 1680-7316 1680-7324 https://doaj.org/article/41b1612c647a4016a692112cccbc8e21 Atmospheric Chemistry and Physics, Vol 23, Pp 1641-1660 (2023) Physics QC1-999 Chemistry QD1-999 article 2023 ftdoajarticles https://doi.org/10.5194/acp-23-1641-2023 2023-01-29T01:26:24Z Satellite-based aerosol optical depth (AOD) has gained popularity as a powerful data source for calibrating aerosol models and correcting model errors through data assimilation. However, simulated airborne particle mass concentrations are not directly comparable to satellite-based AODs. For this, an AOD operator needs to be developed that can convert the simulated mass concentrations into model AODs. The AOD operator is most sensitive to the input of the particle size and chemical composition of aerosols. Furthermore, assumptions regarding particle size vary significantly amongst model AOD operators. More importantly, satellite retrieval algorithms rely on different size assumptions. Consequently, the differences between the simulations and observations do not always reflect the actual difference in aerosol amount. In this study, the sensitivity of the AOD operator to aerosol properties has been explored. We conclude that, to avoid inconsistencies between the AOD operator and retrieved properties, a common understanding of the particle size is required. Accordingly, we designed a hybrid assimilation methodology ( hybrid AOD assimilation) that includes two sequentially conducted procedures. First, aerosol size in the model operator has been brought closer to the assumption of the satellite retrieval algorithm via assimilation of Ångström exponents. This ensures that the model AOD operator is more consistent with the AOD retrieval. The second step in the methodology concerns optimization of aerosol mass concentrations through direct assimilation of AOD ( standard AOD assimilation). The hybrid assimilation method is tested over the European domain using Moderate Resolution Imaging Spectroradiometer (MODIS) Deep Blue products. The corrections made to the model aerosol size information are validated through a comparison with the ground-based Aerosol Robotic Network (AERONET) optical product. The increments in surface aerosol mass concentration that occur due to either the standard AOD assimilation analysis or the ... Article in Journal/Newspaper Aerosol Robotic Network Directory of Open Access Journals: DOAJ Articles Atmospheric Chemistry and Physics 23 2 1641 1660 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Physics QC1-999 Chemistry QD1-999 |
spellingShingle |
Physics QC1-999 Chemistry QD1-999 J. Jin B. Henzing A. Segers How aerosol size matters in aerosol optical depth (AOD) assimilation and the optimization using the Ångström exponent |
topic_facet |
Physics QC1-999 Chemistry QD1-999 |
description |
Satellite-based aerosol optical depth (AOD) has gained popularity as a powerful data source for calibrating aerosol models and correcting model errors through data assimilation. However, simulated airborne particle mass concentrations are not directly comparable to satellite-based AODs. For this, an AOD operator needs to be developed that can convert the simulated mass concentrations into model AODs. The AOD operator is most sensitive to the input of the particle size and chemical composition of aerosols. Furthermore, assumptions regarding particle size vary significantly amongst model AOD operators. More importantly, satellite retrieval algorithms rely on different size assumptions. Consequently, the differences between the simulations and observations do not always reflect the actual difference in aerosol amount. In this study, the sensitivity of the AOD operator to aerosol properties has been explored. We conclude that, to avoid inconsistencies between the AOD operator and retrieved properties, a common understanding of the particle size is required. Accordingly, we designed a hybrid assimilation methodology ( hybrid AOD assimilation) that includes two sequentially conducted procedures. First, aerosol size in the model operator has been brought closer to the assumption of the satellite retrieval algorithm via assimilation of Ångström exponents. This ensures that the model AOD operator is more consistent with the AOD retrieval. The second step in the methodology concerns optimization of aerosol mass concentrations through direct assimilation of AOD ( standard AOD assimilation). The hybrid assimilation method is tested over the European domain using Moderate Resolution Imaging Spectroradiometer (MODIS) Deep Blue products. The corrections made to the model aerosol size information are validated through a comparison with the ground-based Aerosol Robotic Network (AERONET) optical product. The increments in surface aerosol mass concentration that occur due to either the standard AOD assimilation analysis or the ... |
format |
Article in Journal/Newspaper |
author |
J. Jin B. Henzing A. Segers |
author_facet |
J. Jin B. Henzing A. Segers |
author_sort |
J. Jin |
title |
How aerosol size matters in aerosol optical depth (AOD) assimilation and the optimization using the Ångström exponent |
title_short |
How aerosol size matters in aerosol optical depth (AOD) assimilation and the optimization using the Ångström exponent |
title_full |
How aerosol size matters in aerosol optical depth (AOD) assimilation and the optimization using the Ångström exponent |
title_fullStr |
How aerosol size matters in aerosol optical depth (AOD) assimilation and the optimization using the Ångström exponent |
title_full_unstemmed |
How aerosol size matters in aerosol optical depth (AOD) assimilation and the optimization using the Ångström exponent |
title_sort |
how aerosol size matters in aerosol optical depth (aod) assimilation and the optimization using the ångström exponent |
publisher |
Copernicus Publications |
publishDate |
2023 |
url |
https://doi.org/10.5194/acp-23-1641-2023 https://doaj.org/article/41b1612c647a4016a692112cccbc8e21 |
genre |
Aerosol Robotic Network |
genre_facet |
Aerosol Robotic Network |
op_source |
Atmospheric Chemistry and Physics, Vol 23, Pp 1641-1660 (2023) |
op_relation |
https://acp.copernicus.org/articles/23/1641/2023/acp-23-1641-2023.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 doi:10.5194/acp-23-1641-2023 1680-7316 1680-7324 https://doaj.org/article/41b1612c647a4016a692112cccbc8e21 |
op_doi |
https://doi.org/10.5194/acp-23-1641-2023 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
23 |
container_issue |
2 |
container_start_page |
1641 |
op_container_end_page |
1660 |
_version_ |
1766011371729715200 |