1. Bigyani Das and Phil Durbin Adnet Systems Inc./GSFC
Comparison of Column Ozone from OMI with Ground-based Measurements at Three USA Sites
Bigyani Das and Phil Durbin
Adnet Systems Inc./GSFC
OMI Science Team Meeting, Helsinki, June 24-27, 2008

2. OMI Science Team Meeting, Helsinki, June 24-27, 2008
Overview
Question: How do OMI ozone column data compare with ground-based
instruments?
Answer: OMI data does compare well
Method: 3 USA Sites – Houston, Bondville, Raleigh
Ground-based Instruments
USDA (UV network)
NOAA-EPA (NewBrew)
Results: Daily Column Ozone, Monthly Averages, Bias –
All Sky Conditions, Year 2007 (All),
(Bondville & Raleigh versus USDA)
Average Bias (%) Table for [ Bias =1/n ∑(OMI-GB)/GB * 100 ]
USDA-TOMS
USDA-DOAS
NewBrew-TOMS
NewBrew-DOAS
Houston
3.49
3.45
-1.06
-1.03
Bondville
0.31
0.93
0.62
1.27
Raleigh
4.0
4.18
-4.38
-4.20
OMI Science Team Meeting, Helsinki, June 24-27, 2008

3. Ground Based Instruments
USDA UV-B Monitoring and Research Program
(UV-MFRSR) – Ultraviolet Multifilter Rotating
Shadow-band Radiometer
NewBrew - NOAA-EPA Brewer UV and Ozone network (Brewer MkIV Spectrophotometer)
Measurement Sites
Houston, TX (Lat: N, Lon: W)
Bondville, IL (Lat: N, Lon: W)
Raleigh, NC (Lat: N, Lon: W)
OMI Science Team Meeting, Helsinki, June 24-27, 2008

4. Houston – Lat: 29.718(N), Lon: 95.341(W)
OMI Science Team Meeting, Helsinki, June 24-27, 2008

5. Bondville, IL – Lat: 40.053 (N), Lon: 88.372(W)
OMI Science Team Meeting, Helsinki, June 24-27, 2008

6. Raleigh, NC - Lat: 35.728(N), Lon: 78.68(W)
OMI Science Team Meeting, Helsinki, June 24-27, 2008

7. OMI Science Team Meeting, Helsinki, June 24-27, 2008
Bias Comparison
OMI Science Team Meeting, Helsinki, June 24-27, 2008

8. OMI Science Team Meeting, Helsinki, June 24-27, 2008
Bias Comparison:
OMI Science Team Meeting, Helsinki, June 24-27, 2008

9. OMI Science Team Meeting, Helsinki, June 24-27, 2008
Summary
Daily Column Ozone values show good agreement with ground-based measurements
The bias values are site dependent
Maximum bias and average bias have different characteristics.
Maximum bias is less with NewBrew data than USDA data at all 3 sites.
Maximum bias is more at Bondville and Houston than Raleigh when compared with USDA– Reason ?
OMI Science Team Meeting, Helsinki, June 24-27, 2008