1 / 14

Evaluation of Tropospheric Ozone Using Scan Angle Geometry Method (SAM)

This study evaluates the effectiveness of SAM in deriving tropospheric ozone levels from TOMS measurements. Findings show correlations with CO levels and improvements in detection. SAM provides insight into ozone distribution patterns and shows discrepancies with CCD data. Multiangle Scanning Spectrometer may offer enhanced resolution for ozone monitoring.

winona
Download Presentation

Evaluation of Tropospheric Ozone Using Scan Angle Geometry Method (SAM)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Evaluation of Tropospheric Ozone Derived from Scan Angle Geometry Method (SAM) Jae H. Kim1, Sunmi Na1, and Mike Newchurch2 1; Department of Atmospheric Science, Pusan Nat’l University 2; Department of Atmospheric Science, University of Alabama, Huntsville

  2. Scan-Angle Method Algorithm Weighting function of Diff Tropospheric ozone  scaling factor x Diff + 30DU (scaling factor = 6.7) Problem Diff can not directly apply to TOMS because measurements do not occurs simultaneous both at nadir and at high scan position.

  3. Scan-Angle Method How to apply to TOMS • Orbital drift causes FOV at nadir position to overlap closely with the FOV at high scan position about two days later. • Select a box with 15 degree longitude and 2 degree latitude • Diff is sum of retrieval efficiency difference and stratospheric ozone • difference between two scan positions. • => this method can only applicable where daily stratospheric • ozone variation is relatively small and smooth => tropics.

  4. Scan-Angle Method Improvement EP-only SAM ADEOS-EP SAM

  5. SAM & Aerosol Index The correlation between diff & AI

  6. SAM GEOS-CHEM CCD Fire Counts Carbon Monoxide Comparison (Dec-Jan-Feb)

  7. SAM GEOS-CHEM CCD Fire Counts Carbon Monoxide Comparison (Mar-Apr-May)

  8. SAM GEOS-CHEM CCD Fire Counts Carbon Monoxide Comparison (Jun-Jul-Aug)

  9. SAM GEOS-CHEM CCD Fire Counts Carbon Monoxide Comparison (Sep-Oct-Nov)

  10. Comparison Abidjan (5ºN 4 º W)

  11. Comparison Madras (13 º N 80 º E)

  12. Comparison Bangkok (14 º N 101 º E)

  13. Evaluation • The correlation between the SAM results and CO is higher for the December-February period corresponding to the northern burning season. • The correlation between the CCD results and CO is higher during the October-November period corresponding to the southern burning season. • The correlation between the SAM and CCD results shows a disagreement for December-February period, the northern burning season.

  14. Conclusions • Tropospheric ozone signal can be detected by using TOMS error depending on scan angle geometery. • Number of data sampling give an improvement for ozone derivation from SAM => Multiangle Scanning Spectrometer may be able to provide tropospheric ozone derivation with a better temporal and spatial resolution. • The SAM observes the elevated ozone over northern equatorial Africa during the northern burning season (Dec-Feb), which is consistent with fire counts and CO measurements. However, the feature is not reported by the CCD results.On the contrary, the CCD shows elevated ozone always over southern Africa. • The seasonal variation of ozone distribution from SAM agrees well with those from MOZAIC and GEOS-CHEM at Abidjan, Madras, and Bangkok. However, not from CCD.

More Related