Carbon Dioxide and Energy Exchanges in the Coastal Zone of Hudson Bay.

摘要

An eddy covariance system and micrometeorological station was deployed at two locations along the coastline of Hudson Bay during the summers of 2005 and 2006 to document and to understand mass and energy fluxes in high-latitude intertidal and near-shore environments. Despite the proximity of these two zones, it was found that they exhibited distinctly different characteristics. The near-shore zone was a sink for CO2 with an average uptake of -0.11 mumol˙m-2˙s-1 and the intertidal zone tended to be a source of CO2 with an average efflux of 0.04 mumol˙m-2˙s-1 with considerable variability due to the action of the tides. Sensible heat fluxes in the near-shore zone tended to be small and negative and both latent and sensible heat fluxes were significantly enhanced in the intertidal zone. Significantly, increasing wind velocities did not appear to play a role in the enhancement of these fluxes and onshore winds were observed to be unusually dry. As such, key differences were observed that stood in contrast to the results and the conclusions of other flux studies conducted in similar high-latitude coastal-marine environments. It is suggested that these differences could only be understood in the context of the proximity of these areas of living and dead kelp, their respective differences in water depth and the occasional occurrence of a sea-breeze effect that may have implications for the observed fluxes in these areas.