 |
| Titel |
Improved satellite retrievals of NO2 and SO2 over the Canadian oil sands and comparisons with surface measurements |
| VerfasserIn |
C. A. McLinden, V. Fioletov, K. F. Boersma, S. K. Kharol, N. Krotkov, L. Lamsal, P. A. Makar, R. V. Martin, J. P. Veefkind, K. Yang |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 14, no. 7 ; Nr. 14, no. 7 (2014-04-09), S.3637-3656 |
| Datensatznummer |
250118579
|
| Publikation (Nr.) |
 copernicus.org/acp-14-3637-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
| Satellite remote sensing is increasingly being used to monitor air quality
over localized sources such as the Canadian oil sands. Following an initial
study, significantly low biases have been identified in current NO2 and
SO2 retrieval products from the Ozone Monitoring Instrument (OMI)
satellite sensor over this location resulting from a combination of its rapid
development and small spatial scale. Air mass factors (AMFs) used to convert
line-of-sight "slant" columns to vertical columns were re-calculated for
this region based on updated and higher resolution input information
including absorber profiles from a regional-scale
(15 km × 15 km resolution) air quality model, higher spatial and
temporal resolution surface reflectivity, and an improved treatment of snow.
The overall impact of these new Environment Canada (EC) AMFs led to
substantial increases in the peak NO2 and SO2 average vertical
column density (VCD), occurring over an area of intensive surface mining, by
factors of 2 and 1.4, respectively, relative to estimates made with previous
AMFs. Comparisons are made with long-term averages of NO2 and SO2
(2005–2011) from in situ surface monitors by using the air quality model to
map the OMI VCDs to surface concentrations. This new OMI-EC product is able
to capture the spatial distribution of the in situ instruments (slopes of
0.65 to 1.0, correlation coefficients of >0.9). The
concentration absolute values from surface network observations were in
reasonable agreement, with OMI-EC NO2 and SO2 biased low by roughly
30%. Several complications were addressed including correction for the
interference effect in the surface NO2 instruments and smoothing and
clear-sky biases in the OMI measurements. Overall these results highlight the
importance of using input information that accounts for the spatial and
temporal variability of the location of interest when performing retrievals. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|