Tropospheric Emission Spectrometer (TES) satellite observations of ammonia, methanol, formic acid, and carbon monoxide over the Canadian oil sands: validation and model evaluation
The wealth of air quality information provided by satellite infrared observations of ammonia (NH<sub>3</sub>), carbon monoxide (CO), formic acid (HCOOH), and methanol (CH<sub>3</sub>OH) is currently being explored and used for a number of applications, especially at regional...
Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2015-12-01
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Series: | Atmospheric Measurement Techniques |
Online Access: | http://www.atmos-meas-tech.net/8/5189/2015/amt-8-5189-2015.pdf |
Summary: | The wealth of air quality information provided by satellite infrared
observations of ammonia (NH<sub>3</sub>), carbon monoxide (CO), formic acid
(HCOOH), and methanol (CH<sub>3</sub>OH) is currently being explored and used for
a number of applications, especially at regional or global scales. These
applications include air quality monitoring, trend analysis, emissions, and
model evaluation. This study provides one of the first direct validations of
Tropospheric Emission Spectrometer (TES) satellite-retrieved profiles of
NH<sub>3</sub>, CH<sub>3</sub>OH, and HCOOH through comparisons with coincident aircraft
profiles. The comparisons are performed over the Canadian oil sands region
during the intensive field campaign (August–September, 2013) in support of
the Joint Canada–Alberta Implementation Plan for Oil Sands Monitoring
(JOSM). The satellite/aircraft comparisons over this region during this
period produced errors of (i) +0.08 ± 0.25 ppbv for NH<sub>3</sub>, (ii) +7.5 ± 23 ppbv for CO, (iii) +0.19 ± 0.46 ppbv for HCOOH, and
(iv) −1.1 ± 0.39 ppbv for CH<sub>3</sub>OH. These values mostly agree with
previously estimated retrieval errors; however, the relatively large
negative bias in CH<sub>3</sub>OH and the significantly greater positive bias for
larger HCOOH and CO values observed during this study warrant further
investigation. Satellite and aircraft ammonia observations during the field
campaign are also used in an initial effort to perform preliminary
evaluations of Environment Canada's Global Environmental Multi-scale –
Modelling Air quality and CHemistry (GEM-MACH) air quality modelling system
at high resolution (2.5 × 2.5 km<sup>2</sup>). These initial results indicate a
model underprediction of ~ 0.6 ppbv (~ 60 %)
for NH<sub>3</sub>, during the field campaign period. The TES/model CO
comparison differences are ~ +20 ppbv (~ +20 %), but given that under these conditions the TES/aircraft comparisons
also show a small positive TES CO bias indicates that the overall model
underprediction of CO is closer to ~ 10 % at 681 hPa
(~ 3 km) during this period. |
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ISSN: | 1867-1381 1867-8548 |