HR: 14:56h
AN: OS43B-05    [Abstracts]
TI: Carbon Dioxide Exchange and Sea Water Optical Properties in the Coastal Arctic Ocean
AU: * Makshtas, A
EM: maksh@aari.nw.ru
AF: Arctic and Antarctic Research Institute, 38 Bering Str., St. Petersburg, 199397 Russian Federation
AU: Vlasenkov, R
EM: vlasenkov@list.ru
AF: Arctic and Antarctic Research Institute, 38 Bering Str., St. Petersburg, 199397 Russian Federation
AU: Semiletov, I
EM: igorsm@iarc.uaf.edu
AF: IARC/UAF, 930 Koyukuk Dr., Fairbanks, AK 99775 United States
AB: Based on climatic data consisting of routine measurements of carbon dioxide concentration at Barrow, Alaska, satellite data about sea ice area in the eastern part of the Arctic Ocean, and ship observations of pCO2 and sea water optical properties the hypotheses about influence of ice conditions and transparency of sea water for photosynthetic active radiation (PAR) in the Arctic Ocean is elaborated. It is found that surface seawater in the ice-free Arctic shelf seas is mostly unsaturated in CO2 and therefore serves as a sink for atmospheric CO2. In contrast, during winter when the seas are ice-covered, the water beneath sea ice is strongly oversaturated by CO2 and, respectively, reverses CO2 flux to atmosphere. Same time the coastal areas, strongly influenced by coastal erosion and river input of terrestrial carbon and particulate materials (suspended and dissolved), and as result owing the low transparency for PAR are the sources of CO2 into the atmosphere year-round. During field measurements on fast ice near Barrow in early summer the absorption of atmospheric CO2 by the ice-covered ocean dominates, especially through melt ponds. The first results of continuous direct pCO2 measurements beneath ice indicate the possible role of early photosynthesis on pCO2 decline.
DE: 0428 Carbon cycling (4806)
DE: 1030 Geochemical cycles (0330)
DE: 1615 Biogeochemical cycles, processes, and modeling (0412, 0414, 0793, 4805, 4912)
DE: 4217 Coastal processes
DE: 4264 Ocean optics (0649)
SC: Ocean Sciences [OS]
MN: Fall Meeting 2005