Impact of data quality and surface-to-column representativeness on the PM<sub>2.5</sub> / satellite AOD relationship for the contiguous United States
Satellite-derived aerosol optical depth (AOD) observations have been used to estimate particulate matter smaller than 2.5 μm (PM<sub>2.5</sub>). However, such a relationship could be affected by the representativeness of satellite-derived AOD to surface aerosol particle mass concentratio...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2014-06-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/14/6049/2014/acp-14-6049-2014.pdf |
| Summary: | Satellite-derived aerosol optical depth (AOD) observations have been used to
estimate particulate matter smaller than 2.5 μm (PM<sub>2.5</sub>). However,
such a relationship could be affected by the representativeness of
satellite-derived AOD to surface aerosol particle mass concentration and
satellite AOD data quality. Using purely measurement-based methods, we have
explored the impacts of data quality and representativeness on the AOD-inferred
PM<sub>2.5</sub> / AOD relationship for the contiguous United States
(CONUS). This is done through temporally and spatially collocated data sets of
PM<sub>2.5</sub> and AOD retrievals from Aqua/Terra Moderate Resolution Imaging
Spectroradiometer (MODIS), Multi-angle Imaging Spectroradiometer (MISR), and
Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP). These analyses
show that improving data quality of satellite AOD, such as done with data
assimilation-grade retrievals, increases their correlation with PM<sub>2.5</sub>.
However, overall correlation is relatively low across the CONUS. Also,
integrated extinction observed within 500 m above ground level (a.g.l.),
as measured by CALIOP, is not well representative of the total column AOD.
Surface aerosol in the eastern CONUS is better correlated with total column AOD than in the western
CONUS. The best correlation values are found for estimated dry mass CALIOP
extinction at 200–300 m a.g.l. and PM<sub>2.5</sub>, but additional work is
needed to address the ability of using actively sensed AOD as a proxy for
PM<sub>2.5</sub> concentrations. |
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| ISSN: | 1680-7316 1680-7324 |