ocOC - from Ocean Colour to Organic Carbon

• Main Authors: Heim, Birgit, Doerffer, Roland, Overduin, Pier Paul, Lantuit, Hugues, Hoelemann, Jens, Kassens, Heidi, Wegner, Carolyn
• Format: Conference Object
• Language: unknown
• Published: 2011
• Subjects: Arctic; Laptev Sea; IPY; laptev; lena river
• Online Access: https://epic.awi.de/id/eprint/25357/; http://www.conferences.earsel.org/abstract/show/2399; https://hdl.handle.net/10013/epic.38427

The terrigenous carbon export into the Arctic shelf systems is a major component of the Arctic Organic Carbon (OC) cycle. Mac Guire et al. in their review on the Arctic Carbon Cycle recommendate to strengthen observations and design the research sector of 'scaling' that is a key challenge to link the processes observed and understood on fine scales to larger scales, e.g., needed for modeling. Here, remote sensing observations can become important tools. Recent development of satellite ocean color sensors such as MODIS, SeaWiFS, MERIS has been accompanied by an increased effort to establish Ocean Colour (OC) algorithms (e.g., for chlorophyll, suspended matter, coloured dissolved organic matter). The ‘OCoc-from Ocean Colour to Organic Carbon’ project (IPY-project 1176), funded by the German Research Foundation (DFG), is an Ocean Colour study joined with the Arctic Coastal Dynamics ACD network and Arctic Circum-polar Coastal Observatory Network ACCO-Net (IPY-project 90). OCoc uses MERIS data for synoptical monitoring of terrigenous suspended and organic matter in the late-summer ice-free waters of the Laptev See region. MERIS Reduced Resolution (RR)-LIB data are processed towards optical aquatic parameters using Beam-Visat4.2 and the MERIS case2 regional processor for coastal application (C2R). Calculated aquatic parameters are optical coefficients and calculated concentrations of chlorophyll, total suspended matter and coloured dissolved organic matter absorption from the water leaving reflectances. The Laptev Sea is characterized by a very shallow topography and considerable Regions of Fresh water Influence ROFIs. The maximum river discharge of the Lena River, the second largest Arctic river in terms of annual fresh water discharge happens during the spring ice-breakup in June. Fluvial systems serve as point sources for high fluxes of dissolved and particulate terrigenous materials. The Laptev Sea coast is a highly dynamic mainly sedimentary ice-rich system that delivers vast amounts of interstorage carbon and old carbon from syncryogenic deposits. Initial comparisons with expedition data (cDOM, transparency, SPM, turbidity, chlorophyll) from the German-Russian TRANSDRIFT expeditions and from German-Russian expeditions at the Laptev Sea Coast (2008 to 2010) are presented. MERIS-C2R optical parameters such as the first attenuation depth, ’Z90’, seem adequately to represent true conditions. Whereas the derived concentration parameters seem to be overestimated. The synoptic information of the optical MERIS-C2R parameters offers an immediate wealth of information. The spatial patterns of the processed MERIS C2R time series show the inter-annual scale of the atmospherically driven large-scale circulation patterns. On event scales, we need to investigate if weather patterns potentially contribute to short pulses and circulation patterns.