Title: Satellite%20Remote%20Sensing%20of%20Ozone-NOx-VOC%20Sensitivity
1Satellite Remote Sensing of Ozone-NOx-VOC
Sensitivity
Randall Martin Aaron Van Donkelaar
Arlene Fiore
2Ozone Control Strategies Require Independent
Information on Effectiveness of Reducing NOx or
VOCs
HCHO/NOy Ratio Used as Indicator Would like to
Observe from Space
(ppbv)
NOx-Saturated
NOx-Sensitive
Sillman and He, 2002
3Conduct Three Simulations With GEOS-CHEM Model
- Base Case
- Reduce Anthropogenic NOx Emissions by 50
- Reduce Anthropogenic VOC Emissions by 50
4Tropospheric HCHO/NO2 Column Ratio Is an
Indicator of the Sensitivity of Afternoon Surface
Ozone to NOx and VOC Emissions in a Well-mixed
EnvironmentGEOS-CHEM Model Calculation For
Polluted Regions, Mar-Nov
NOx Saturated
NOx Sensitive
5Tropospheric NO2 and HCHO Columns Largely
Confined Near the SurfaceAlso Closely Related to
NOx and VOC Emissions
Tropospheric NO2 column ENOx Tropospheric HCHO
column EVOC
Boundary Layer
CO
NO2
NO
HCHO
hours
NO/NO2 ? ? W ALTITUDE
OH
HO2
hours
VOC
hours
HNO3
Emission
Emission
Nitrogen Oxides (NOx)
Volatile Organic Compounds (VOC)
6Retrieve Tropospheric NO2 and HCHO Columns from
GOMELargest Errors (from AMF) Cancel in the Ratio
Solar Io
Backscattered intensity IB
Spectral Fit (UV/Vis)
Total HCHO NO2 Slant Column
Remove Stratosphere
Tropospheric NO2 Slant Column
Scattering by Earth surface and by atmosphere
Calculate AMF
Tropospheric NO2 HCHO Column
7GOME Observations Show NOx-Sensitive Conditions
Over Most Polluted Regions During AugustMajor
Industrial Areas are Clear Exceptions
White areas indicate clouds or data below the
GOME detection limit
August
8Biomass Burning Emissions are Clearly
NOx-Sensitive, In Contrast with NOx-Saturated
Conditions Over the Industrial Highveld
Also observe plume evolution
August
9Seasonal Evolution from NOx-Sensitive to
NOx-Saturated Conditions in Fall
10GOME Observations Provide Confidence in a Recent
Model Prediction NOx-Sensitive in the South and
NOx-Saturated in the North in Fall
Seasonal Maximum in Surface Ozone in Urban China
Occurs in Fall (More High-Pressure Systems)
GOME
Model
Luo et al., JGR, 2000
11Conclusions
- Satellite Observations of the Tropospheric
HCHO/NO2 Column Indicate Ozone-NOx-VOC
Sensitivity - Errors in Ratio Less Than for Individual Species
- Sensitive Tool for Ozone Model Evaluation
- OMI Will Be Launched in June
- 40 Times Higher Spatial Resolution
- Less sub-grid scale variation
- Afternoon observation time