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Proceedings Paper

Speckles of satellite chlorophyll-a concentration data and removal process optimized to the East Japan Sea
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Paper Abstract

Characteristics of speckle errors of Sea-viewing Wide Field-of-view Sensor (SeaWiFS) chlorophyll-a concentration were analyzed, and its removal process was presented in the East Japan Sea from September 1997 to December 2007. Level-3 data of SeaWiFS chlorophyll-a concentration provided by NASA showed significant speckle errors in the East Japan Sea. The speckles with anomalously high concentrations were randomly distributed and showed remarkably high bias, compared with their neighboring pixels. The speckles tended to appear frequently in winter, which might be related to cloud distribution. Ten-year averaged cloudiness of winter was much higher over the southeastern part, with frequent speckles, than the northwestern part of the East Japan Sea. Statistical analysis results showed that the number of the speckles was increased as cloudiness increased. Herein, we present a methodology of how to remove the speckles with highly anomalous chlorophyll concentration data using Level-2 data and how to composite the chlorophyll-a data to generate Level-3 data. Considering seasonal variations of the speckles and their statistical characteristics, dynamic threshold methods were given. Additional methodology for high values during spring bloom was also developed by considering the chlorophyll-a concentration frontal zone. After applying the methodology to ten-year Level-2 data, data composite of Level-2 was carried out to produce Level-3 product and compared with the NASA product. The results showed that most speckles were disappeared and more than 10% errors of 5°×5° mean values were reduced at speckle regions in the southeast East/Japan Sea. This study raised the issue about speckle errors in chlorophyll-a concentration composite from SeaWiFS data in the East Japan Sea for the first time and presented regionally-optimized composite method for more reliable chlorophyll-a data in oceanic application researches.

Paper Details

Date Published: 3 November 2010
PDF: 5 pages
Proc. SPIE 7858, Remote Sensing of the Coastal Ocean, Land, and Atmosphere Environment, 78581G (3 November 2010); doi: 10.1117/12.873239
Show Author Affiliations
Hwa-Jeong Chae, Seoul National Univ. (Korea, Republic of)
Kyung-Ae Park, Seoul National Univ. (Korea, Republic of)

Published in SPIE Proceedings Vol. 7858:
Remote Sensing of the Coastal Ocean, Land, and Atmosphere Environment
Robert J. Frouin; Hong Rhyong Yoo; Joong-Sun Won; Aiping Feng, Editor(s)

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