1. Randall Martin Mid-July
USE OF GEOS-CHEM BY SMITHSONIAN ASTROPHYSICAL OBSERVATORY AND DALHOUSIE UNIVERSITY
Randall Martin
Mid-July
Halifax, Nova Scotia
SAO

2. Typical resolution (km)
RETRIEVAL AND INTERPRETATION OF SATELLITE OBSERVATIONS OF THE TROPOSPHERE
Instrument
Coverage
Typical resolution (km)
GOME
1995-
40x320
SCIAMACHY
2002-
30x60
OMI
2004-
13x24
NO2, HCHO, O3, SO2, BrO

3. GEOS-CHEM MODEL IDENTIFIES FAVORABLE REGIONS TO DETERMINE STRATOSPHERIC COLUMN AND INSTRUMENT BIASES
Martin et al., 2002

4. SLANT COLUMNS OF TROPOSPHERIC NO2 FROM GOME
1996
Martin et al., 2002

5. USE GEOS-CHEM TO CALCULATE AMFs FOR NO2 and HCHO FOR EVERY SATELLITE VIEWING SCENE
GEOS-CHEM GLOBAL 3-D MODEL
OF TROPOSPHERIC CHEMISTRY:
provides shape factors
LIDORT
RAD.TRANSFER MODEL:
provides scattering weights
AMF
spectral
fit
SATELLITE
DATA
SLANT
COLUMN
VERTICAL
COLUMN
Best information applied to each scene
Consistency in comparing model and observed columns
ADVANTAGES OF
3-D MODEL APPROACH
FOR COMPUTING AMFs

6. OPTIMIZE INVENTORY USING A PRIORI BOTTOM-UP AND GOME TOP-DOWN INFORMATION
Determine NOx Emissions from GOME Observations Using GEOS-CHEM to Provide Information on the NOx/NO2 Ratio and NOx Lifetime
GOME Tropospheric NO2
GEOS-CHEM Tropospheric NO2
Martin et al., 2003
1015 molecules cm-2

7. IN THE QUEUE: GEOS-CHEM NOX EMISSIONS WILL REFLECT ADDITIONAL GOME INFORMATION
Annual mean ratio (A posteriori / A priori)
Martin et al., 2003

8. EXAMINE SEASONAL VOC EMISSIONS USING GOME AND GEOS-CHEM HCHO COLUMNS: SAO Role in Retrieval, AMFs, and Model Simulation
MAR
JUL
APR
AUG
MAY
SEP
JUN
OCT
Abbot et al., 2003

9. EL NINO INTERANNUAL VARIABILITY IN OZONE: DIFFERENCE BETWEEN OCT 97 AND OCT 96
TOMS
Chandra et al. [2002]

10. Dobson Units for March, April, May
TOMS/MLS TROPOSPHERIC OZONE PROVIDES FURTHER EVIDENCE THAT OZONE IS TOO HIGH OVER INDIA
30 N
Dobson Units for March, April, May
TOMS/MLS
30 S
30 N
GEOS-CHEM
Chandra et al., 2003
30 S

11. OPERATIONAL HCHO RETRIEVAL ALGORITHM FOR OMI
Uses Monthly Mean HCHO Shape Factors from GEOS-CHEM
SUPPORT FOR GMI
Provide GEOS-CHEM results for various simulations (i.e. with and without aerosols)
Assist interpretation of model results
EVALUATE GEOS-CHEM SIMULATION OF NOX
With In Situ NO2 Measurements from SOS (1999) and TEXAQS (2000)

12. FUTURE USE OF GEOS-CHEM AT DALHOUSIE
Likely local platforms:
8-Processor 1.2 GHz Sun Fire (Works!, credit Yantosca)
20-Processor 700 MHz SGI Origin 350
Continued support for GMI Real-time HCHO and NO2 Retrievals from SCIAMACHY for INTEX Use Shape Factors from GEOS-CHEM Retrieval and Interpretation of HCHO, NO2, SO2, O3, BrO, CO from TOMS / GOME / SCIAMACHY / OMI Interpretation of satellite observations from MOPITT, MODIS, TES, … and aircraft missions such as INTEX, ITCT-2K4, …