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Oceanography
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Derivation of Aerosol Optical Thickness over the East Asian Oceans
with ROCSAT-1 OCI Imagery
4. Conclusion
From the comparison of SeaWiFS data, the results of this study have high correlation with those of SeaDAS. The AOT also agrees with the AERONET in situ data. We will find more data pairs of OCI and AERONET measurements to validate our algorithm in the future. However, the algorithm developed in this study is capable to retrieve the AOT. According to our result, the seasonal fluctuation of AOT can be revealed clearly with OCI data. The serious aerosol will occur in spring and fall. It shows that the Mainland's dust storm may affect the atmosphere constituent around Taiwan area. Because of its 35° inclination and on-board memory space limitation, ROCSAT-1 OCI can not take image in same area during short period. Hence, we will try to map the aerosol distribution and monthly aerosol variation with multi-temporal OCI images in next study.
Acknowledgements
The SeaWiFS data, used in this study, were provided by the Goddard DAAC, NASA, USA. The OCI data were provided by the OCI Data Distribution Center, NSPO, Taiwan. This study was supported by the NSPO, NSC, with the grant of NSC89-NSPO-A-OCI-019-01-02.
References
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Ignatov, A. M., L.L. Stowe, S. M. Sakerin, and G.K. Korotaev, 1995: Validation of the NOAA/NESDIS satellite aerosol product over the North Atlantic in 1989. J. Geophy. Res. Vol. 100, No. D3, pp.5123-5132.
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Table 1. The observation time of OCI images covering Taiwan area.
| Date |
UTC |
Date |
UTC |
| 1999/3/26 |
0205z |
2000/2/19 |
0215z |
| 1999/5/17 |
0211z |
2000/3/22 |
0411z |
| 1999/6/8 |
2321z |
2000/3/29 |
0115z |
| 1999/7/13 |
0710z |
2000/5/5 |
0754z |
| 1999/8/19 |
0713z |
2000/5/8 |
0707z |
| 1999/9/2 |
0122z |
2000/6/4 |
0139z |
| 1999/10/10 |
0717z |
2000/6/26 |
0831z |
Figure 1. The Comparison of aerosol optical thickness derived from SeaWiFS data by the OCITRAN and the SeaDAS models.
aeronet oberved AOT
Figure 2. The comparison of aerosol optical thickness at 865nm band derived from OCI data and Aeronet data observed on Southern Korea (Corrcoef=0.995, std=0.0069).
date
Figure 3. The variation of averaged aerosol optical thickness retrieved from OCI 865nm band around Penghu (23N, 119E).
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