Open AccessDynamics of pCO 2 and related air‐ice CO 2 fluxes in the Arctic coastal zone (Amundsen Gulf, Beaufort Sea)
Author(s) -
Geilfus N.X.,
Carnat G.,
Papakyriakou T.,
Tison J.L.,
Else B.,
Thomas H.,
Shadwick E.,
Delille B.
Publication year - 2012
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2011jc007118
Subject(s) - sea ice , meltwater , oceanography , brine , melt pond , arctic ice pack , arctic , carbon dioxide , environmental science , seawater , geology , antarctic sea ice , chemistry , snow , geomorphology , organic chemistry
We present an Arctic seasonal survey of carbon dioxide partial pressure (pCO 2 ) dynamics within sea ice brine and related air‐ice CO 2 fluxes. The survey was carried out from early spring to the beginning of summer in the Arctic coastal waters of the Amundsen Gulf. High concentrations of pCO 2 (up to 1834 μ atm) were observed in the sea ice in early April as a consequence of concentration of solutes in brines, CaCO 3 precipitation and microbial respiration. CaCO 3 precipitation was detected through anomalies in total alkalinity (TA) and dissolved inorganic carbon (DIC). This precipitation seems to have occurred in highly saline brine in the upper part of the ice cover and in bulk ice. As summer draws near, the ice temperature increases and brine pCO 2 shifts from a large supersaturation (1834 μ atm) to a marked undersaturation (down to almost 0 μ atm). This decrease was ascribed to brine dilution by ice meltwater, dissolution of CaCO 3 and photosynthesis during the sympagic algal bloom. The magnitude of the CO 2 fluxes was controlled by ice temperature (through its control on brine volume and brine channels connectivity) and the concentration gradient between brine and the atmosphere. However, the state of the ice‐interface clearly affects air‐ice CO 2 fluxes.