Partial Pressure of CO_2 in the Near-Water Air Layer along the Transatlantic Section in November-December 2000

摘要

Along the transatlantic section running from 57~° N to 60~° S,which was executed from November 7 to December 19,2000,from on board the R/V Horizont II,the concentrations of CO_2 were measured in the near-water layer of the air and the differences between the partial pressures in the water and the air in various climatic zones were calculated.It was shown that the variations of the CO_2 concentrations in the near-water layer of the air and those of the values of the water-air partial pressure difference were from 324 x 10~(-6) to 426 x 10~(-6) and from -150 x 10~(-6) to 100 x l0~(-6) atm,respectively.The maximum value of the CO_2 partial pressure in the air in the near-water layer (426 x 10~(-6) atm) was noted at 45~°-7~° N;the minimum of 324 x 10~(-6) atm was found in Antarctica at 59~° S.For the time considered,the maximum value of the CO_2 partial pressure difference in the water and air (-150 x 10~(-6) atm) was observed at 45~°-48~° N;the maximum flux in this case was directed from the atmosphere to the water.The maximum value of the CO_2 partial pressure difference in the water and air for the flux directed from the ocean to the air (100 x 10~(-6) atm) was observed at 59~°-60~° S.The comparison of the calculated values of the partial pressure difference in the water and the air with the previous data points to a more intense exchange of CO_2 between the ocean and atmosphere during the survey period considered.In so doing,judging from the values of the CO_2 partial pressure difference in the air and water as compared to 1975,the exchange intensity in the Northern Hemisphere (absorption from the atmosphere) increased.A well-pronounced latitudinal effect of the distribution of the CO_2 partial pressure in the air was observed.Along the vessel route,variations in the CO_2 concentrations in the zones of water divergence and convergence were registered.