Mobile mini-DOAS measurement of the outflow of NO2 [NO subscript 2] and HCHO from Mexico City
We here present the results from mobile measurements using two ground-based zenith viewing Differential Optical Absorption Spectroscopy (DOAS) instruments. The measurement was performed in a cross-section of the plume from the Mexico City Metropolitan Area (MCMA) on 10 March 2006 as part of the...
| Main Authors: | , , , , , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
European Geosciences Union / Copernicus
2011
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| Online Access: | http://hdl.handle.net/1721.1/65361 https://orcid.org/0000-0002-3596-5334 |
| Summary: | We here present the results from mobile measurements
using two ground-based zenith viewing Differential
Optical Absorption Spectroscopy (DOAS) instruments. The
measurement was performed in a cross-section of the plume
from the Mexico City Metropolitan Area (MCMA) on 10
March 2006 as part of the MILAGRO field campaign. The
two instruments operated in the UV and the visible wavelength
region respectively and have been used to derive the
differential vertical columns of HCHO and NO2 [NO subscript 2] above the
measurement route. This is the first time the mobile mini-
DOAS instrument has been able to measure HCHO, one of
the chemically most important and interesting gases in the
polluted urban atmosphere.
Using a mass-averaged wind speed and wind direction
from the WRF model the instantaneous flux of HCHO and
NO2 [NO subscript 2] has been calculated from the measurements and the results
are compared to the CAMx chemical model. The calculated
flux through the measured cross-section was 1.9 (1.5–
2.2) kg/s of HCHO and 4.4 (4.0–5.0) kg/s of NO2 [NO subscript 2] using the
UV instrument and 3.66 (3.63–3.73) kg/s of NO2 [NO subscript 2] using the
visible light instrument. The modeled values from CAMx
for the outflow of both NO2 [NO subscript 2] and HCHO, 1.1 and 3.6 kg/s,
respectively, show a reasonable agreement with the measurement
derived fluxes. |
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