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dc.contributor.authorEspedal, Heidi A.eng
dc.contributor.authorJohannessen, Ola M.eng
dc.contributor.authorJohannessen, Johnny A.eng
dc.contributor.authorDano, E.eng
dc.contributor.authorLyzenga, D. R.eng
dc.contributor.authorKnulst, Johaneng
dc.date.accessioned2005-10-03T08:15:49Z
dc.date.available2005-10-03T08:15:49Z
dc.date.issued1998-10-15eng
dc.identifier.citationJournal of Geophysical Research: Oceans, 103(C11): 24969-24982en
dc.identifier.issn0148-0227eng
dc.identifier.urihttp://hdl.handle.net/1956/810
dc.description.abstractOcean mesoscale phenomena such as eddies and current convergence zones can often be seen in synthetic aperture radar (SAR) images due to characteristic patterns caused by natural film induced damping of the waves. Such films have also been found to exert a significant effect on air-sea gas exchange, which may be important for the global scale climate system. Satellite SAR may prove very useful to quantify the extent of natural film. To investigate the composition of these films and their effect on radar return, we compared samples of the sea surface with ERS 1/2 SAR images of coastal ocean areas during the COASTWATCH’95 experiment. Simultaneous observations were made with a shipmounted C band dual-polarized Doppler radar, and surface drifters were deployed to investigate the surface current variations in the vicinity of different slicks (areas where the short surface waves sensed by a radar are damped). One confirmed case of natural film was thus verified to be caused by a convergence zone. The study also showed that the films investigated during COASTWATCH’95 were generally less concentrated and originated from marine organisms, compared to the films with terrestrial influences found in a previous experiment in a fjord [Espedal et al., 1996]. The dependence of the existence of the films on wind speed is also investigated, and an estimate of natural film distribution during the experiment period is given, using a total of 71 ERS 1/2 SAR images collected over the same coastal area under a variety of wind conditions. Up to 40% natural film coverage was found for 2.5 m/s wind speeds, while already at 5–10 m/s all SAR imagery had under 5% film coverage.en
dc.format.extent6423690 byteseng
dc.format.mimetypeapplication/pdfeng
dc.language.isoengeng
dc.publisherAmerican Geophysical Unioneng
dc.relation.ispartofseries
dc.subjectOceanographyeng
dc.subjectRemote sensingeng
dc.titleCOASTWATCH´95: ERS 1/2 SAR detection of natural film on the ocean surfaceeng
dc.typeJournal articleeng
dc.typePeer reviewedeng
dc.rights.holderCopyright 1998 American Geophysical Union
bora.peerreviewedPeer reviewedeng
bibo.doihttp://dx.doi.org/10.1029/98JC01660eng
dc.identifier.doihttp://dx.doi.org/10.1029/98JC01660


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