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| Titel |
Optical characterisation of suspended particles in the Mackenzie River plume (Canadian Arctic Ocean) and implications for ocean colour remote sensing |
| VerfasserIn |
D. Doxaran, J. Ehn, S. Bélanger, A. Matsuoka, S. Hooker, M. Babin |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 9, no. 8 ; Nr. 9, no. 8 (2012-08-22), S.3213-3229 |
| Datensatznummer |
250007244
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| Publikation (Nr.) |
 copernicus.org/bg-9-3213-2012.pdf |
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| Zusammenfassung |
Climate change significantly impacts Arctic shelf regions in terms of air
temperature, ultraviolet radiation, melting of sea ice, precipitation,
thawing of permafrost and coastal erosion. Direct consequences have been
observed on the increasing Arctic river flow and a large amount of organic
carbon sequestered in soils at high latitudes since the last glacial maximum
can be expected to be delivered to the Arctic Ocean during the coming
decade. Monitoring the fluxes and fate of this terrigenous organic carbon is
problematic in such sparsely populated regions unless remote sensing
techniques can be developed and proved to be operational.
The main objective of this study is to develop an ocean colour algorithm to
operationally monitor dynamics of suspended particulate matter (SPM) on the
Mackenzie River continental shelf (Canadian Arctic Ocean) using satellite
imagery. The water optical properties are documented across the study area
and related to concentrations of SPM and particulate organic carbon (POC).
Robust SPM and POC : SPM proxies are identified, such as the light
backscattering and attenuation coefficients, and relationships are
established between these optical and biogeochemical parameters. Following a
semi-analytical approach, a regional SPM quantification relationship is
obtained for the inversion of the water reflectance signal into SPM
concentration. This relationship is reproduced based on independent field
optical measurements. It is successfully applied to a selection of MODIS
satellite data which allow estimating fluxes at the river mouth and
monitoring the extension and dynamics of the Mackenzie River surface plume
in 2009, 2010 and 2011. Good agreement is obtained with field observations
representative of the whole water column in the river delta zone where
terrigenous SPM is mainly constrained (out of short periods of maximum river
outflow). Most of the seaward export of SPM is observed to occur within the
west side of the river mouth.
Future work will require the validation of the developed SPM regional
algorithm based on match-ups with field measurements, then the routine
application to ocean colour satellite data in order to better estimate the
fluxes and fate of SPM and POC delivered by the Mackenzie River to the
Arctic Ocean. |
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