NOTE: The reorganization of working groups is planned during the CARINA conference in Gran Canaria in February 2003.

Several ad-hoc working groups emerged from the discussions. The topics and the names of those, who expressed interest, are listed in the following. The list of topics is not meant to be comprehensive as also the name list is not exclusive.

A number of cross-over points exist for the North Atlantic data collection, mainly at the intersection of meridional and zonal transects. These points are to be identified and hydrographic data (T,S) are to be compared first. At depth horizons, where no obvious change in the water mass composition can be detected, values of carbon parameters (CT, AT, pCO2) and other available parameters (nutrients, oxygen, CFCs) shall be compared to identify possible offsets between cruises.

(Alex Kozyr, Nathalie Lefèvre, Ludger Mintrop, Taro Takahashi, Rik Wanninkhof)

Many measurements have been made along the 20°W meridian, starting with the BOFS cruises (1989) and including cruises in May 1992 (METEOR 21/3), August 1993 (OACES-NATL), July 1996 (METEOR 36/2) and April 1998 and further cruises from the British AMT (Atlantic Meridional Transect) program. These data could be favorably used to i) cross-check deep water values, ii) analyze seasonal changes is surface and mixed layer samples, iii) monitor long term changes in CO2-properties.

(Iris Aristegui, Arne Körtzinger, Nathalie Lefèvre, Ludger Mintrop, Denise Smythe-Wright, Helmuth Thomas, Rik Wanninkhof)

Several methods exist for the calculation of anthropogenic CO2 from total dissolved inorganic carbon concentrations. The all involve certain assumptions, require additional measured parameters and rely on water mass properties and water mass circulation characteristics. For the North Atlantic as an area of water mass formation, the determination of preformed values should be especially important to address a comparison of different approaches.

(Iris Aristegui, Nick Bates, Catherine Goyet, Arne Körtzinger, Ludger Mintrop, Jon Olafsson, Aida Rios, Denise Smythe-Wright, Doug Wallace)

In order to monitor, document and understand possible changes in oceanic CO2 inventories, we need to observe changes in CO2 and related properties (such as pCO2, CT, AT, nutrients, oxygen and isotopes of carbon) in key areas of the region. The areas of special interest certainly include the overturning regimes, where convection links surface and deep ocean. These areas are the GIN seas, the Iceland-Scotland Sill / Rockall Trough area, the Iceland-Greenland Sill and Irminger Sea, and the Labrador Sea and Deep Western Boundary Current area.

(Leif Anderson, Iris Aristegui, Peter Jones, Arne Körtzinger, Liliane Merlivat, Jon Olafsson)

In analogue to the transport calculation of heat, also the carbon transport can be calculated using data from (preferentially) zonal transects. This approach had been followed in the South Atlantic and the data coverage available for the North Atlantic makes a similar calculation for this ocean promising. This approach also includes interpolation of carbon concentrations from multi-parameter fits.

(Catherine Goyet, Jürgen Holfort, Aida Rios, Doug Wallace)

The amount of pCO2 data has increased substantially during the last few years ,also by making use of VOS observations. This will very much improve the mapping of DpCO2 in the North Atlantic by season or even by month. Data gaps may be closed by coordination of future field studies.

(Nick Bates, Catherine Goyet, Arne Körtzinger, Nathalie Lefèvre, Liliane Merlivat, Aida Rios, Bernd Schneider, Taro Takahashi)

The use of merchant vessels for unattended measurements of surface parameters (mainly pCO2) has been introduced as a VOS (voluntary observing ship) program since a few years. Selection of ships and routes and the coordination of individual programs as well as cooperation in sensor development and improvement shall be a topic for a CARINA workgroup. This may also include method developments for buoy based systems.

(Arne Körtzinger, Nathalie Lefèvre, Denise Smythe-Wright, Michel Stoll, Rik Wanninkhof)