 |
| Titel |
A Novel Method to Estimate Surface NO2 Concentrations from the Space-borne Ozone Monitoring Instrument |
| VerfasserIn |
Yanshun Li, Qiang Zhang, Guannan Geng, Yixuan Zheng, Jianping Guo |
| Konferenz |
EGU General Assembly 2017
|
| Medientyp |
Artikel
|
| Sprache |
en
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250142426
|
| Publikation (Nr.) |
 EGU/EGU2017-6047.pdf |
|
|
|
|
|
| Zusammenfassung |
| Atmospheric NO2near the surface has notable health effects and is precursor of tropospheric
ozone. In this work, we propose a novel method to estimate daily surface NO2 concentrations
from the Ozone Monitoring Instrument (OMI) with improved accuracy. Two chemical
transport models GEOS-Chem and WRF/CMAQ are used to simulate converting factors
between OMI column densities and surface concentrations. GEOS-Chem is found to better
capture the distribution of converting factors, while CMAQ has advantage in simulating the
magnitude. We combine the two models to calculate optimal values of converting
factors and further constrain them by using colocated boundary layer heights (BLH)
derived from fine-resolution sounding observations made at OMI overpass time.
Calculated converting factors over Chinese Mainland vary by more than three orders of
magnitude (10−18 ∼10−15 μg⋅cm−1⋅molecule−1), indicating complexity of NO2
vertical structure over large spatial extent. We generate a map of surface NO2 mass
concentrations during June 2013 from OMI retrievals at 0.1˚ ×0.1˚ grids. Estimated
concentrations from our novel method show reasonable spatial agreement with in
situ chemiluminescent measurements (R = 0.70, Slope = 0.58, N = 353), which
significantly outperform estimations using only GEOS-Chem (R = 0.60, Slope =
0.20, N = 353) or WRF/CMAQ (R = 0.19, Slope = 0.52, N = 353) to simulate the
converting factor. Preliminary results show that the novel method developed in this study
could improve capability of satellite sensors to quantify surface NO2 pollution. |
|
|
|
|
|
|