Ecoinformatics Problems of the World Ocean - New Ecoinformatics Tools in Environmental Science: Applications and Decision-making - page 269

atmosphere. These values are non-uniformly distributed over the water surface and
strongly vary in time. The characteristic place in the CO 2 exchange is occupied by
the Arctic Ocean, whose low temperatures determine a high absolute content of
CO 2 dissolved in the surface layer in any season. On the average, in the summer,
the arctic waters mainly assimilate CO 2 and emit O 2 to the atmosphere, whereas in
winter they emit CO 2 and assimilate O 2 . This clearly expressed seasonal change is
smoothed down in the basins of the North Atlantic seas where a decrease of the ice
cover, an increase of the period of photosynthetic activity and the existing fall-
winter vertical convection lead to an intensi

cation of the gas exchange with the

10 9 tC/
year of the amount of CO 2 assimilated from the atmosphere. The contribution of the
arctic water basins into the removal of excess carbonic acid from the atmosphere is
small compared to the total assimilation of CO 2 by the World Ocean, which is
estimated at 5.2

atmosphere towards prevailing of the H 3

fl flux. Carbon constitutes 0.18 ×

10 9 tC/year, (Table 4.2 ). However, this assessment is rather
underestimated, considering the results obtained by Kelley (1987). The average
estimates show that the partial pressure of CO 2 in the atmosphere exceeds that in
the arctic seas by 110 ppm. The CO 2 de

6.6 ×

-

cit in the marine medium takes place
mainly during springtime blossoming and is estimated at 450 gC/m 2 . This means *

that the CO 2 fl flux from the atmosphere into the marine medium can vary from 1.5 to

4.0 gC/m 2 /day. This assessment changes considerably as a function of longitude.
For instance, the Norwegian Sea has a de

cit of the CO 2 partial pressure between

20 and 50 ppm, and the Bering Sea 70 ppm. A clear linear correlation is

observed with the proportion coefficient 10 ppm CO 2 per

ʔ p CO2 ≅

° C between the CO 2

content in the sea water and its temperature.

Table 4.2 Annual budget of CO 2 exchange with the atmosphere for water bodies of the Arctic
Basin and northern seas (10 6 tC/year) (McGuire et al. 2010)

Region of the
ocean

Summer Winter Year

Assimilation Emission Balance Assimilation Emission Balance

Arctic Basin 4.4 0.0 +4.4 +4.4

- - -

Arctic Seas
East Sibrian
Sea

1.0 2.1 − 1.1 0.0 0.7 − 0.7 − 1.8

Kara Sea 11.4 2.4 +9.0 0.0 0.2 − 0.2 +8.8

Laptev Sea 2.4 3.6 − 1.2 0.0 2.9 − 2.9 − 4.1

Chuckchee
Sea

11.2 0.0 +11.2 0.0 0.6 − 0.6 +10.6

Total 26.0 8.1 +17.9 0.0 4.4 − 4.4 +13.5

North Atlantic Seas
Barents Sea

71.9 0.0 +71.9 0.0 0.0 0.0 +71.9

Greenland Sea 19.1 0.0 +19.1 8.7 0.0 +8.7 +27.8

Norwegian
Sea

64.8 0.0 +64.8 0.0 6.0 +6.0 +5.8

Total 155.8 0.0 +155.8 8.7 6.0 +2.7 +158.5

Arctic Ocean
on the whole

186.2 8.1 +178.1 8.7 10.4 − 1.7 +176.4