Aerosol layer height (ALH) retrievals from oxygen absorption bands: intercomparison and validation among different satellite platforms, GEMS, EPIC, and TROPOMI
<p>The vertical distribution of aerosols is crucial for assessing surface air quality and its impact on the climate. Although aerosol vertical structures can be complex, assuming a certain shape for the aerosol vertical profile allows for the retrieval of a single parameter – aerosol layer hei...
Saved in:
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2025-01-01
|
| Series: | Atmospheric Measurement Techniques |
| Online Access: | https://amt.copernicus.org/articles/18/327/2025/amt-18-327-2025.pdf |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1832592602204995584 |
|---|---|
| author | H. Kim H. Kim X. Chen X. Chen J. Wang J. Wang J. Wang J. Wang Z. Lu Z. Lu Z. Lu M. Zhou G. R. Carmichael G. R. Carmichael S. S. Park J. Kim |
| author_facet | H. Kim H. Kim X. Chen X. Chen J. Wang J. Wang J. Wang J. Wang Z. Lu Z. Lu Z. Lu M. Zhou G. R. Carmichael G. R. Carmichael S. S. Park J. Kim |
| author_sort | H. Kim |
| collection | DOAJ |
| description | <p>The vertical distribution of aerosols is crucial for assessing surface air quality and its impact on the climate. Although aerosol vertical structures can be complex, assuming a certain shape for the aerosol vertical profile allows for the retrieval of a single parameter – aerosol layer height (ALH) – from passive remote sensing measurements. In this study, we evaluate ALH products retrieved using oxygen absorption measurements from multiple satellite platforms: the Geostationary Environment Monitoring Spectrometer (GEMS) focusing on Asia, the Earth Polychromatic Imaging Camera (EPIC) in deep space, and the polar-orbiting TROPOspheric Monitoring Instrument (TROPOMI). We use the extinction-weighted aerosol optical centroid height (AOCH) derived from aerosol extinction profiles of Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) as the ground truth. The differences due to the inconsistent definitions of ALH in various retrieval algorithms are investigated and eliminated before comparison. We select multiple dust and smoke cases under ideal observational conditions, referred to as “golden days”, for the evaluation. Given the significant role of aerosol optical depth (AOD) in ALH retrieval, we first evaluate the AOD from these retrievals against the ground-based AErosol RObotic NETwork (AERONET). Results show that the GEMS AOD at 440 nm has better agreement with the AERONET AOD of the <span class="inline-formula">∼</span> 0.9 correlation coefficient (<span class="inline-formula"><i>R</i></span>) than that at 680 nm, both of which underestimate with a negative bias. In contrast, EPIC and TROPOMI tend to overestimate AOD by 0.33 and 0.23 for dust cases, while the bias for smoke plumes is small. Evaluation of ALH against CALIOP demonstrates that the EPIC/TROPOMI ALH has good consistency (<span class="inline-formula"><i>R</i></span> <span class="inline-formula">></span> 0.7) with CALIOP but is overestimated by approximately 0.8 km. The GEMS ALH displays minimal bias (0.1 km) but a slightly lower correlation (<span class="inline-formula"><i>R</i></span> <span class="inline-formula">=</span> 0.64). Intercomparisons between three passive retrievals indicate that GEMS retrievals have a limited consistency with EPIC and TROPOMI of 0.3–0.4 <span class="inline-formula"><i>R</i></span>, while GEMS underestimates with ALHs of <span class="inline-formula">∼</span> 0.3 and <span class="inline-formula">∼</span> 0.6 km compared with TROPOMI and EPIC, respectively. The correlations improve under conditions of higher absorbing aerosols (UVAI <span class="inline-formula">≥</span> 3), as the signal in the oxygen absorption band (O<span class="inline-formula"><sub>2</sub></span>–O<span class="inline-formula"><sub>2</sub></span> used by GEMS) is enhanced. Although the ALH diurnal cycle from EPIC and GEMS shows some differences, they both demonstrate ALH descent in the afternoon, which might be related to the boundary layer process. Case<span id="page328"/> studies show that the EPIC ALH indicates a morning ascent to around 4.5 km, while the GEMS ALH remains stable before descending to below 3 km in the afternoon.</p> |
| format | Article |
| id | doaj-art-d75caeba10a14db69853294eeac3932e |
| institution | Kabale University |
| issn | 1867-1381 1867-8548 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Measurement Techniques |
| spelling | doaj-art-d75caeba10a14db69853294eeac3932e2025-01-21T06:54:16ZengCopernicus PublicationsAtmospheric Measurement Techniques1867-13811867-85482025-01-011832734910.5194/amt-18-327-2025Aerosol layer height (ALH) retrievals from oxygen absorption bands: intercomparison and validation among different satellite platforms, GEMS, EPIC, and TROPOMIH. Kim0H. Kim1X. Chen2X. Chen3J. Wang4J. Wang5J. Wang6J. Wang7Z. Lu8Z. Lu9Z. Lu10M. Zhou11G. R. Carmichael12G. R. Carmichael13S. S. Park14J. Kim15Department of Chemical and Biochemical Engineering, The University of Iowa, Iowa City, IA 52242, USACenter for Global and Regional Environmental Research (CGRER), The University of Iowa, Iowa City, IA 52242, USADepartment of Chemical and Biochemical Engineering, The University of Iowa, Iowa City, IA 52242, USACenter for Global and Regional Environmental Research (CGRER), The University of Iowa, Iowa City, IA 52242, USADepartment of Chemical and Biochemical Engineering, The University of Iowa, Iowa City, IA 52242, USACenter for Global and Regional Environmental Research (CGRER), The University of Iowa, Iowa City, IA 52242, USAIowa Technology Institute, The University of Iowa, Iowa City, IA 52242, USAInterdisciplinary Graduate Program in Informatics, The University of Iowa, Iowa City, IA 52242, USACenter for Global and Regional Environmental Research (CGRER), The University of Iowa, Iowa City, IA 52242, USAIowa Technology Institute, The University of Iowa, Iowa City, IA 52242, USAInterdisciplinary Graduate Program in Informatics, The University of Iowa, Iowa City, IA 52242, USAGoddard Earth Sciences Technology and Research (GESTAR) II, University of Maryland – Baltimore County, Baltimore, MD 21228, USADepartment of Chemical and Biochemical Engineering, The University of Iowa, Iowa City, IA 52242, USACenter for Global and Regional Environmental Research (CGRER), The University of Iowa, Iowa City, IA 52242, USASchool of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of KoreaDepartment of Atmospheric Sciences, Yonsei University, Seoul 03722, South Korea<p>The vertical distribution of aerosols is crucial for assessing surface air quality and its impact on the climate. Although aerosol vertical structures can be complex, assuming a certain shape for the aerosol vertical profile allows for the retrieval of a single parameter – aerosol layer height (ALH) – from passive remote sensing measurements. In this study, we evaluate ALH products retrieved using oxygen absorption measurements from multiple satellite platforms: the Geostationary Environment Monitoring Spectrometer (GEMS) focusing on Asia, the Earth Polychromatic Imaging Camera (EPIC) in deep space, and the polar-orbiting TROPOspheric Monitoring Instrument (TROPOMI). We use the extinction-weighted aerosol optical centroid height (AOCH) derived from aerosol extinction profiles of Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) as the ground truth. The differences due to the inconsistent definitions of ALH in various retrieval algorithms are investigated and eliminated before comparison. We select multiple dust and smoke cases under ideal observational conditions, referred to as “golden days”, for the evaluation. Given the significant role of aerosol optical depth (AOD) in ALH retrieval, we first evaluate the AOD from these retrievals against the ground-based AErosol RObotic NETwork (AERONET). Results show that the GEMS AOD at 440 nm has better agreement with the AERONET AOD of the <span class="inline-formula">∼</span> 0.9 correlation coefficient (<span class="inline-formula"><i>R</i></span>) than that at 680 nm, both of which underestimate with a negative bias. In contrast, EPIC and TROPOMI tend to overestimate AOD by 0.33 and 0.23 for dust cases, while the bias for smoke plumes is small. Evaluation of ALH against CALIOP demonstrates that the EPIC/TROPOMI ALH has good consistency (<span class="inline-formula"><i>R</i></span> <span class="inline-formula">></span> 0.7) with CALIOP but is overestimated by approximately 0.8 km. The GEMS ALH displays minimal bias (0.1 km) but a slightly lower correlation (<span class="inline-formula"><i>R</i></span> <span class="inline-formula">=</span> 0.64). Intercomparisons between three passive retrievals indicate that GEMS retrievals have a limited consistency with EPIC and TROPOMI of 0.3–0.4 <span class="inline-formula"><i>R</i></span>, while GEMS underestimates with ALHs of <span class="inline-formula">∼</span> 0.3 and <span class="inline-formula">∼</span> 0.6 km compared with TROPOMI and EPIC, respectively. The correlations improve under conditions of higher absorbing aerosols (UVAI <span class="inline-formula">≥</span> 3), as the signal in the oxygen absorption band (O<span class="inline-formula"><sub>2</sub></span>–O<span class="inline-formula"><sub>2</sub></span> used by GEMS) is enhanced. Although the ALH diurnal cycle from EPIC and GEMS shows some differences, they both demonstrate ALH descent in the afternoon, which might be related to the boundary layer process. Case<span id="page328"/> studies show that the EPIC ALH indicates a morning ascent to around 4.5 km, while the GEMS ALH remains stable before descending to below 3 km in the afternoon.</p>https://amt.copernicus.org/articles/18/327/2025/amt-18-327-2025.pdf |
| spellingShingle | H. Kim H. Kim X. Chen X. Chen J. Wang J. Wang J. Wang J. Wang Z. Lu Z. Lu Z. Lu M. Zhou G. R. Carmichael G. R. Carmichael S. S. Park J. Kim Aerosol layer height (ALH) retrievals from oxygen absorption bands: intercomparison and validation among different satellite platforms, GEMS, EPIC, and TROPOMI Atmospheric Measurement Techniques |
| title | Aerosol layer height (ALH) retrievals from oxygen absorption bands: intercomparison and validation among different satellite platforms, GEMS, EPIC, and TROPOMI |
| title_full | Aerosol layer height (ALH) retrievals from oxygen absorption bands: intercomparison and validation among different satellite platforms, GEMS, EPIC, and TROPOMI |
| title_fullStr | Aerosol layer height (ALH) retrievals from oxygen absorption bands: intercomparison and validation among different satellite platforms, GEMS, EPIC, and TROPOMI |
| title_full_unstemmed | Aerosol layer height (ALH) retrievals from oxygen absorption bands: intercomparison and validation among different satellite platforms, GEMS, EPIC, and TROPOMI |
| title_short | Aerosol layer height (ALH) retrievals from oxygen absorption bands: intercomparison and validation among different satellite platforms, GEMS, EPIC, and TROPOMI |
| title_sort | aerosol layer height alh retrievals from oxygen absorption bands intercomparison and validation among different satellite platforms gems epic and tropomi |
| url | https://amt.copernicus.org/articles/18/327/2025/amt-18-327-2025.pdf |
| work_keys_str_mv | AT hkim aerosollayerheightalhretrievalsfromoxygenabsorptionbandsintercomparisonandvalidationamongdifferentsatelliteplatformsgemsepicandtropomi AT hkim aerosollayerheightalhretrievalsfromoxygenabsorptionbandsintercomparisonandvalidationamongdifferentsatelliteplatformsgemsepicandtropomi AT xchen aerosollayerheightalhretrievalsfromoxygenabsorptionbandsintercomparisonandvalidationamongdifferentsatelliteplatformsgemsepicandtropomi AT xchen aerosollayerheightalhretrievalsfromoxygenabsorptionbandsintercomparisonandvalidationamongdifferentsatelliteplatformsgemsepicandtropomi AT jwang aerosollayerheightalhretrievalsfromoxygenabsorptionbandsintercomparisonandvalidationamongdifferentsatelliteplatformsgemsepicandtropomi AT jwang aerosollayerheightalhretrievalsfromoxygenabsorptionbandsintercomparisonandvalidationamongdifferentsatelliteplatformsgemsepicandtropomi AT jwang aerosollayerheightalhretrievalsfromoxygenabsorptionbandsintercomparisonandvalidationamongdifferentsatelliteplatformsgemsepicandtropomi AT jwang aerosollayerheightalhretrievalsfromoxygenabsorptionbandsintercomparisonandvalidationamongdifferentsatelliteplatformsgemsepicandtropomi AT zlu aerosollayerheightalhretrievalsfromoxygenabsorptionbandsintercomparisonandvalidationamongdifferentsatelliteplatformsgemsepicandtropomi AT zlu aerosollayerheightalhretrievalsfromoxygenabsorptionbandsintercomparisonandvalidationamongdifferentsatelliteplatformsgemsepicandtropomi AT zlu aerosollayerheightalhretrievalsfromoxygenabsorptionbandsintercomparisonandvalidationamongdifferentsatelliteplatformsgemsepicandtropomi AT mzhou aerosollayerheightalhretrievalsfromoxygenabsorptionbandsintercomparisonandvalidationamongdifferentsatelliteplatformsgemsepicandtropomi AT grcarmichael aerosollayerheightalhretrievalsfromoxygenabsorptionbandsintercomparisonandvalidationamongdifferentsatelliteplatformsgemsepicandtropomi AT grcarmichael aerosollayerheightalhretrievalsfromoxygenabsorptionbandsintercomparisonandvalidationamongdifferentsatelliteplatformsgemsepicandtropomi AT sspark aerosollayerheightalhretrievalsfromoxygenabsorptionbandsintercomparisonandvalidationamongdifferentsatelliteplatformsgemsepicandtropomi AT jkim aerosollayerheightalhretrievalsfromoxygenabsorptionbandsintercomparisonandvalidationamongdifferentsatelliteplatformsgemsepicandtropomi |