Publications des scientifiques de l'IRD

Dupouy Cécile, Wattelez G., Martias C., Juillot J., Andréoli R., Lille D., Murakami H., Frouin R. (2018). Rain-derived particles and CDOM distribution along the east coast of New Caledonia. Bellingham : SPIE, no 107780K [11 p.]. (Proceedings of SPIE Conferences ; 10778). Remote Sensing of the Open and Coastal Ocean and Inland Waters : SPIE Asia-Pacific Remote Sensing Conference, Honolulu (USA), 2018/09. ISSN 0277-786X.

Titre du document
Rain-derived particles and CDOM distribution along the east coast of New Caledonia
Année de publication
2018
Type de document
Ouvrage
Auteurs
Dupouy Cécile, Wattelez G., Martias C., Juillot J., Andréoli R., Lille D., Murakami H., Frouin R.
Source
Bellingham : SPIE, 2018, no 107780K [11 p.] (Proceedings of SPIE Conferences ; 10778). ISSN 0277-786X
Colloque
Remote Sensing of the Open and Coastal Ocean and Inland Waters : SPIE Asia-Pacific Remote Sensing Conference, Honolulu (USA), 2018/09
Shortly after strong rains or tropical storms, chlorophyll-a concentration (Chla), turbidity, and colored dissolved organic matter (CDOM) in the lagoon of New Caledonia may be tripled. This effect is visible as far as 50 km offshore. The Eastern Coast of New Caledonia is more impacted than the Western Coast because of its geomorphological structure. Higher frequency and intensity of the rains, and the dominance of highly erosive lateritic formations resulted from deep weathering of ultramafic rocks. At the deeper parts of the lagoon (> 20 m), increases of Chla, turbidity, and CDOM absorption can be detected by satellite imagery with their plumes extending off shore as a result of wind-driven circulation in the lagoon. Such increases agree with the oceanographic measurements of Chla, absorption, backscattering, turbidity and CDOM during extensive cruises. Satellite and in situ measurements allow tracing of particulates and dissolved matter in lagoon waters and up to the coral barrier reefs. The largest particles settle at a short distance from the coast influencing the sediments not far from the river outflows. Fine particles (< 10 µm), colloids and/or CDOM are exported to reefs where they can be beneficial through protection from high UV illumination (colloids) and feeding of the corals (CDOM). Phytoplankton and associated detritus, when not dominated by toxic filamentous cyanobacteria, can also feed coral reefs. Finally, the export of fine particles associated with colloids and/or CDOM can also contribute to the distribution of trace metals to the barrier reefs of the East Coast and offshore. The question whether this input of trace metals has an overall positive or negative effect on the coral reefs is still under debate.
Plan de classement
Milieux physico-chimique [032MILPHY] ; Océanographie [126TELAPP05]
Descripteurs
LAGON ; RECIF CORALLIEN ; CYCLE BIOGEOCHIMIQUE ; QUALITE DE L'EAU ; MATIERE ORGANIQUE DISSOUTE ; TURBIDITE ; REFLECTANCE ; IMAGE SATELLITE ; PHYTOPLANCTON
Description Géographique
NOUVELLE CALEDONIE ; PACIFIQUE ; ZONE TROPICALE
Localisation
Fonds IRD [F B010074698]
Identifiant IRD
fdi:010074698
Contact