Ocean Colour Remote Sensing in Polar Seas

Co-Chairs:

Dr. Marcel Babin
Canada Excellence Research Chair in “Remote Sensing of Canada’s New Arctic Frontier”
Joint International Laboratory (Université Laval, Canada & CNRS, France), “Takuvik” (UMI 3376)
Université Laval, Québec, Canada
Email: marcel.babin@takuvik.ulaval.ca

Dr. Kevin Arrigo
Stanford University, CA
USA
Email: arrigo@stanford.edu

Dr. Simon Bélanger
Université du Québec à Rimouski,
Canada
Email: simon_belanger@uqar.qc.ca

Scientific and programmatic background and rationale

Ocean colour remote sensing has often been used to study polar seas, especially in Antarctica where the optical properties of the upper ocean are not as complex as they are in the Arctic (e.g. Comiso et al. 1990, 1993, Sullivan et al. 1993, Arrigo et al. 1998, Stramski et al. 1999, Arrigo et al. 2008a). These data suggest that primary production in Antarctic waters has changed little over the last 14 years (Arrigo et al. 2008a). In contrast, spectacular impacts of climate change have been observed recently in the Arctic Ocean, including the receding of the summer ice cover by 30% over the last 3 decades (Comiso et al. 2008). It is predicted that it will disappear almost completely by the end of the current century (Holland et al. 2006, Serreze et al. 2007) and perhaps much earlier (Wand and Overland 2009). As a consequence of perennial ice receding, the pan-Arctic primary production, as well as the photooxidation of colored dissolved organic matter, seem to be increasing (Bélanger et al. 2006, Pabi et al. 2008, Arrigo et al. 2008b). The annual maximum phytoplankton biomass is now reached earlier in several Arctic seas (Kahru et al. 2010). As the extent of the seasonal ice zone will increase (difference between the annual maximum and minimum extents), ice-edge blooms may play an increasing role (Perrette et al. 2010).

The ongoing changes within the context of accelerating climate change call for a vastly improved understanding of the polar ecosystems based on an intensive observation program. In situ observations from ships are however inherently sparse in space and time, especially in the inaccessible Arctic Ocean. Ocean colour remote sensing is certainly one of the most appropriate tools to extensively monitor marine ecosystems, and it provides recurrent pan-Arctic and pan-Antarctic observations at relatively low cost.

The use of ocean colour remote sensing in polar regions is, however, impeded by a number of difficulties and intrinsic limitations including the prevailing low solar elevations, the impact of ice on remotely-sensed reflectance, the deep chlorophyll maximum (DCM), the peculiar phytoplankton photosynthetic parameters, the optical complexity of seawater especially over the Arctic shelves and, persistence of clouds and fog (click here for further details).