GEOTRACES Standards and Intercalibration Committee met to review Atlantic Ocean data

The Committee has now examined more than 8000 data points

The GEOTRACES Standards and Intercalibration Committee (G. Cutter, Chair; P. Andersson, L. Codispoti, P. Croot, R. Francois, M. Lohan, H. Obata, and M. van der Loeff) met 1-3 May 2013 at the Swedish Museum of Natural History in Stockholm, Sweden to review Atlantic Ocean crossover station results and discuss several issues of relevance to the committee; the meeting was hosted by Per Andersson. It is important to remember that the S&I Committee’s charge is to ensure that accurate and precise data are generated in the GEOTRACES Program through the use of appropriate sampling protocols, analytical standards and certified reference materials, and the active sharing of methods and results, with this last item being intercalibration.

International GEOTRACES Standards and Intercalibration Committee members at their May 2013 meeting at the Swedish Museum of Natural History in Stockholm. L-R: Greg Cutter, Roger Francois, Maeve Lohan, Lou Codispoti, Peter Croot, Hajime Obata, Michiel van der Loeff, and Per Andersson who hosted the meeting.

Of course there are few reference materials that actually represent real ocean waters, so as much as possible GEOTRACES cruises occupy stations along their transects that have been occupied by another GEOTRACES cruise, thus creating the “crossover” stations. At these crossovers data, particularly those in deeper waters, can be directly compared and if statistically significant differences are found, the investigators who generated the data can work together to resolve any underlying issues, for example differences in calibration or blanking. To date the S&I Committee has now examined more than 8000 data for trace elements and isotopes, mainly in the Atlantic Ocean, and water column hydrography (temperature, salinity, nutrients, and oxygen concentrations as a function of depth). Much of the data reviewed will be incorporated into the 2014 GEOTRACES Intermediate Data Product. Notices on the S&I Committee evaluations have been sent to all the data suppliers, and the Committee will meet again in late September 2013 for a re-evaluation of results that have been resubmitted after a thorough intercalibration by the cruises’ participants.