Air-sea CO2 exchange in the Gulf of Bothnia, Baltic Sea

作者：Loeffler Annekatrin; Schneider Bernd; Perttila Matti; Rehder Gregor

来源：Continental Shelf Research, 2012, 37: 46-56.

DOI：10.1016/j.csr.2012.02.002

• Carbon dioxide
• Partial pressure
• Gas exchange
• Air-sea-fluxes
• Gulf of Bothnia
• Baltic Sea

The surface water CO2 partial pressure, pCO(2), was measured during nine cruises in the Gulf of Bothnia at different seasons between 1999 and 2010, with continuous recording during most of the cruises using a bubble-type equilibrator and infrared CO2 detection. The data were used to construct the mean seasonality of the pCO(2) in characteristic sub-areas. The low pCO(2) measured in spring/summer and the high pCO(2) measured in fall/winter indicated that biological production, stratification, mineralization and deep mixing, controlled the seasonal pCO(2) cycle in both the Bothnian Bay and the Bothnian Sea. To calculate CO2 exchange with the atmosphere, the gas exchange transfer velocity was computed as a function of wind speed according to Wanninkhof et al. (2009). Based on the mean seasonal pCO(2) distribution. CO2 fluxes were calculated, taking into account the differing wind conditions and the varying ice coverage. The resulting mean annual flux of +140 mmol m(-2) yr(-1) in the Bothnian Bay indicated that this area is a weak source for atmospheric CO2. In contrast, the Bothnian Sea was found to act as a sink for atmospheric CO2, with a mean flux of -730 mmol m(-2) yr(-1).

• 出版日期2012-4-1