We describe the OceanFlux Greenhouse Gases methodology for creating an ocean surface CO2 climatology. In situ measurements valid for instantaneous sea surface temperature (SST) were recomputed using a more consistent and averaged SST. The results were normalised to year 2010, averaged by month, and interpolated onto a global 1°×1° grid. The 12 monthly distributions of ocean surface CO2 (see supplement) can be used in air-sea gas flux calculations together with climatologies of other variables.

In this paper, we used combines two existing methods (i.e. self-organizing maps and multiple linear regression) to estimate the ocean surface partial pressure of CO2 in the Baltic Sea from the remotely sensed sea surface temperature, chlorophyll, coloured dissolved organic matter, net primary production, and mixed-layer depth. The outputs of this research have a horizontal resolution of 4km and cover the 1998–2011 period. These outputs give a monthly map of the Baltic Sea.

Our article presents successful gas exchange measurements obtained in a large-scale wind-wave tank. The adopted box model methodology, experimental produce and instrumentation are described in detail. For the first time, parallel measurements of total transfer velocities for 14 individual gases within a wide range of solubility have been achieved. Various wind speed conditions and the effect of surfactant layers have been investigated providing exciting results.

A comparative study of simultaneous heat and gas exchange measurements was performed in the large annular Heidelberg Air-Sea Interaction Facility, the Aeolotron, under homogeneous water surface conditions, including the measurement of the Schmidt number exponent. Provided the Schmidt number exponent is known and that the heated patch is large enough to reach the thermal equilibrium, it is possible to scale heat transfer velocities measured by active thermography to gas transfer velocities.