Evaluation of downwelling diffuse attenuation coefficient algorithms in the Red Sea

Handle URI:
http://hdl.handle.net/10754/618016
Title:
Evaluation of downwelling diffuse attenuation coefficient algorithms in the Red Sea
Authors:
Tiwari, Surya Prakash ( 0000-0001-8833-132X ) ; Yellepeddi, Sarma B. ( 0000-0003-3727-434X ) ; Jones, Burton ( 0000-0002-9599-1593 )
Abstract:
Despite the importance of the optical properties such as the downwelling diffuse attenuation coefficient for characterizing the upper water column, until recently no in situ optical measurements were published for the Red Sea. Kirby et al. used observations from the Coastal Zone Color Scanner to characterize the spatial and temporal variability of the diffuse attenuation coefficient (Kd(490)) in the Red Sea. To better understand optical variability and its utility in the Red Sea, it is imperative to comprehend the diffuse attenuation coefficient and its relationship with in situ properties. Two apparent optical properties, spectral remote sensing reflectance (Rrs) and the downwelling diffuse attenuation coefficient (Kd), are calculated from vertical profile measurements of downwelling irradiance (Ed) and upwelling radiance (Lu). Kd characterizes light penetration into water column that is important for understanding both the physical and biogeochemical environment, including water quality and the health of ocean environment. Our study tests the performance of the existing Kd(490) algorithms in the Red Sea and compares them against direct in situ measurements within various subdivisions of the Red Sea. Most standard algorithms either overestimated or underestimated with the measured in situ values of Kd. Consequently, these algorithms provided poor retrieval of Kd(490) for the Red Sea. Random errors were high for all algorithms and the correlation coefficients (r2) with in situ measurements were quite low. Hence, these algorithms may not be suitable for the Red Sea. Overall, statistical analyses of the various algorithms indicated that the existing algorithms are inadequate for the Red Sea. The present study suggests that reparameterizing existing algorithms or developing new regional algorithms is required to improve retrieval of Kd(490) for the Red Sea. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
KAUST Department:
Red Sea Research Center (RSRC)
Citation:
Surya Prakash Tiwari ; Y. V. B. Sarma and Burton H. Jones " Evaluation of downwelling diffuse attenuation coefficient algorithms in the Red Sea ", Proc. SPIE 9878, Remote Sensing of the Oceans and Inland Waters: Techniques, Applications, and Challenges, 987804 (May 7, 2016); doi:10.1117/12.2222823; http://dx.doi.org/10.1117/12.2222823
Publisher:
SPIE-Intl Soc Optical Eng
Journal:
Remote Sensing of the Oceans and Inland Waters: Techniques, Applications, and Challenges
Conference/Event name:
Remote Sensing of the Oceans and Inland Waters: Techniques, Applications, and Challenges
Issue Date:
7-May-2016
DOI:
10.1117/12.2222823
Type:
Conference Paper
Sponsors:
This study is supported by the King Abdullah University of Science and Technology (KAUST), Kingdom of Saudi Arabia. We thank the operator, master, and crew of R/V Thuwal. We would also thanks to M. Ouhssain, B. Kurten, and several other colleagues provided significant help during field work.
Additional Links:
http://proceedings.spiedigitallibrary.org/proceeding.aspx?doi=10.1117/12.2222823
Appears in Collections:
Conference Papers

Full metadata record

DC FieldValue Language
dc.contributor.authorTiwari, Surya Prakashen
dc.contributor.authorYellepeddi, Sarma B.en
dc.contributor.authorJones, Burtonen
dc.date.accessioned2016-08-07T11:00:34Z-
dc.date.available2016-08-07T11:00:34Z-
dc.date.issued2016-05-07-
dc.identifier.citationSurya Prakash Tiwari ; Y. V. B. Sarma and Burton H. Jones " Evaluation of downwelling diffuse attenuation coefficient algorithms in the Red Sea ", Proc. SPIE 9878, Remote Sensing of the Oceans and Inland Waters: Techniques, Applications, and Challenges, 987804 (May 7, 2016); doi:10.1117/12.2222823; http://dx.doi.org/10.1117/12.2222823en
dc.identifier.doi10.1117/12.2222823-
dc.identifier.urihttp://hdl.handle.net/10754/618016-
dc.description.abstractDespite the importance of the optical properties such as the downwelling diffuse attenuation coefficient for characterizing the upper water column, until recently no in situ optical measurements were published for the Red Sea. Kirby et al. used observations from the Coastal Zone Color Scanner to characterize the spatial and temporal variability of the diffuse attenuation coefficient (Kd(490)) in the Red Sea. To better understand optical variability and its utility in the Red Sea, it is imperative to comprehend the diffuse attenuation coefficient and its relationship with in situ properties. Two apparent optical properties, spectral remote sensing reflectance (Rrs) and the downwelling diffuse attenuation coefficient (Kd), are calculated from vertical profile measurements of downwelling irradiance (Ed) and upwelling radiance (Lu). Kd characterizes light penetration into water column that is important for understanding both the physical and biogeochemical environment, including water quality and the health of ocean environment. Our study tests the performance of the existing Kd(490) algorithms in the Red Sea and compares them against direct in situ measurements within various subdivisions of the Red Sea. Most standard algorithms either overestimated or underestimated with the measured in situ values of Kd. Consequently, these algorithms provided poor retrieval of Kd(490) for the Red Sea. Random errors were high for all algorithms and the correlation coefficients (r2) with in situ measurements were quite low. Hence, these algorithms may not be suitable for the Red Sea. Overall, statistical analyses of the various algorithms indicated that the existing algorithms are inadequate for the Red Sea. The present study suggests that reparameterizing existing algorithms or developing new regional algorithms is required to improve retrieval of Kd(490) for the Red Sea. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.en
dc.description.sponsorshipThis study is supported by the King Abdullah University of Science and Technology (KAUST), Kingdom of Saudi Arabia. We thank the operator, master, and crew of R/V Thuwal. We would also thanks to M. Ouhssain, B. Kurten, and several other colleagues provided significant help during field work.en
dc.publisherSPIE-Intl Soc Optical Engen
dc.relation.urlhttp://proceedings.spiedigitallibrary.org/proceeding.aspx?doi=10.1117/12.2222823en
dc.rightsCopyright 2016 Society of Photo Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.en
dc.titleEvaluation of downwelling diffuse attenuation coefficient algorithms in the Red Seaen
dc.typeConference Paperen
dc.contributor.departmentRed Sea Research Center (RSRC)en
dc.identifier.journalRemote Sensing of the Oceans and Inland Waters: Techniques, Applications, and Challengesen
dc.conference.dateApril 04, 2016en
dc.conference.nameRemote Sensing of the Oceans and Inland Waters: Techniques, Applications, and Challengesen
dc.conference.locationNew Delhi, Indiaen
dc.eprint.versionPublisher's Version/PDFen
kaust.authorTiwari, Surya Prakashen
kaust.authorYellepeddi, Sarma B.en
kaust.authorJones, Burtonen
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