Intercalibration in Chemical Oceanography.[Webpage]

Abstract

This Special Issue, the first of its kind for the journal, is devoted to the topic of intercalibration as applied to chemical measurements in the ocean. Rather than giving a formal metrological definition of intercalibration, it is simply the open sharing of data and expertise by analysts to obtain the same, and hopefully accurate, value for a given parameter such as the concentration, isotopic composition, or chemical speciation of a trace element. Laboratories are said to be intercalibrated when they all get the same values within the experimental errors. It is important to note that this does not mean that each individual laboratory needs to be using the same analytical techniques or even sampling methods, it only is the final results that count; this will be evident in the special issue papers that follow. Most of the papers in this issue are a result of the intercalibration phase of GEOTRACES, an international program to examine the biogeochemistry of trace elements and isotopes (TEIs) in the world s oceans. As so many countries are participating in GEOTRACES and sampling all oceans, it was essential that intercalibration included sampling and sample handling in addition to the analytical steps. Moreover, GEOTRACES studies TEIs in the dissolved and particulate phases, and their chemical forms or speciation, so these add even more to the complexity of performing an intercalibration. All of these aspects of intercalibration in the real ocean are touched upon in this special issue.