Evaluation of Satellite Retrievals of Chlorophyll-a in the Arabian Gulf
The Arabian Gulf is a highly turbid, shallow sedimentary basin whose coastal areas have been classified as optically complex Case II waters (where ocean colour sensors have been proved to be unreliable). Yet, there is no such study assessing the performance and quality of satellite ocean-colour data...
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| Format: | Article |
| Language: | English |
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MDPI AG
2017-03-01
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| Series: | Remote Sensing |
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| Online Access: | http://www.mdpi.com/2072-4292/9/3/301 |
| _version_ | 1818997372816982016 |
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| author | Noora Al-Naimi Dionysios E. Raitsos Radhouan Ben-Hamadou Yousria Soliman |
| author_facet | Noora Al-Naimi Dionysios E. Raitsos Radhouan Ben-Hamadou Yousria Soliman |
| author_sort | Noora Al-Naimi |
| collection | DOAJ |
| description | The Arabian Gulf is a highly turbid, shallow sedimentary basin whose coastal areas have been classified as optically complex Case II waters (where ocean colour sensors have been proved to be unreliable). Yet, there is no such study assessing the performance and quality of satellite ocean-colour datasets in relation to ground truth data in the Gulf. Here, using a unique set of in situ Chlorophyll-a measurements (Chl-a; an index of phytoplankton biomass), collected from 24 locations in four transects in the central Gulf over six recent research cruises (2015–2016), we evaluated the performance of VIIRS and other merged satellite datasets, for the first time in the region. A highly significant relationship was found (r = 0.795, p < 0.001), though a clear overestimation in satellite-derived Chl-a concentrations is evident. Regardless of this constant overestimation, the remotely sensed Chl-a observations illustrated adequately the seasonal cycles. Due to the optically complex environment, the first optical depth was calculated to be on average 6–10 m depth, and thus the satellite signal is not capturing the deep chlorophyll maximum (DCM at ~25 m). Overall, the ocean colour sensors’ performance was comparable to other Case II waters in other regions, supporting the use of satellite ocean colour in the Gulf. Yet, the development of a regional-tuned algorithm is needed to account for the unique environmental conditions of the Gulf, and ultimately provide a better estimation of surface Chl-a in the region. |
| first_indexed | 2024-12-20T21:44:36Z |
| format | Article |
| id | doaj.art-43a482d9552d46c488436ae755467bb0 |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-12-20T21:44:36Z |
| publishDate | 2017-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-43a482d9552d46c488436ae755467bb02022-12-21T19:25:42ZengMDPI AGRemote Sensing2072-42922017-03-019330110.3390/rs9030301rs9030301Evaluation of Satellite Retrievals of Chlorophyll-a in the Arabian GulfNoora Al-Naimi0Dionysios E. Raitsos1Radhouan Ben-Hamadou2Yousria Soliman3Environmental Science Center (ESC), Qatar University (QU), P.O. Box 2317, Doha, QatarPlymouth Marine Laboratory (PML), Prospect Place, The Hoe, Plymouth PL1 3DH, UKDepartment of Biological and Environmental Science, Qatar University (QU), P.O. Box 2317, Doha, QatarDepartment of Biological and Environmental Science, Qatar University (QU), P.O. Box 2317, Doha, QatarThe Arabian Gulf is a highly turbid, shallow sedimentary basin whose coastal areas have been classified as optically complex Case II waters (where ocean colour sensors have been proved to be unreliable). Yet, there is no such study assessing the performance and quality of satellite ocean-colour datasets in relation to ground truth data in the Gulf. Here, using a unique set of in situ Chlorophyll-a measurements (Chl-a; an index of phytoplankton biomass), collected from 24 locations in four transects in the central Gulf over six recent research cruises (2015–2016), we evaluated the performance of VIIRS and other merged satellite datasets, for the first time in the region. A highly significant relationship was found (r = 0.795, p < 0.001), though a clear overestimation in satellite-derived Chl-a concentrations is evident. Regardless of this constant overestimation, the remotely sensed Chl-a observations illustrated adequately the seasonal cycles. Due to the optically complex environment, the first optical depth was calculated to be on average 6–10 m depth, and thus the satellite signal is not capturing the deep chlorophyll maximum (DCM at ~25 m). Overall, the ocean colour sensors’ performance was comparable to other Case II waters in other regions, supporting the use of satellite ocean colour in the Gulf. Yet, the development of a regional-tuned algorithm is needed to account for the unique environmental conditions of the Gulf, and ultimately provide a better estimation of surface Chl-a in the region.http://www.mdpi.com/2072-4292/9/3/301Arabian GulfphytoplanktonChlorophyll-aocean colourremote sensingOC-CCI |
| spellingShingle | Noora Al-Naimi Dionysios E. Raitsos Radhouan Ben-Hamadou Yousria Soliman Evaluation of Satellite Retrievals of Chlorophyll-a in the Arabian Gulf Remote Sensing Arabian Gulf phytoplankton Chlorophyll-a ocean colour remote sensing OC-CCI |
| title | Evaluation of Satellite Retrievals of Chlorophyll-a in the Arabian Gulf |
| title_full | Evaluation of Satellite Retrievals of Chlorophyll-a in the Arabian Gulf |
| title_fullStr | Evaluation of Satellite Retrievals of Chlorophyll-a in the Arabian Gulf |
| title_full_unstemmed | Evaluation of Satellite Retrievals of Chlorophyll-a in the Arabian Gulf |
| title_short | Evaluation of Satellite Retrievals of Chlorophyll-a in the Arabian Gulf |
| title_sort | evaluation of satellite retrievals of chlorophyll a in the arabian gulf |
| topic | Arabian Gulf phytoplankton Chlorophyll-a ocean colour remote sensing OC-CCI |
| url | http://www.mdpi.com/2072-4292/9/3/301 |
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