At the end of 2018 and beginning of 2019, NIVA hosted two Transnational Access (TNA) activities at NIVA’s Research Station at Solbergstrand (NRS). NRS is located about 40 km south of Oslo on the eastern rocky shores of the Oslo fjord. Nearby is the small coastal village of Drøbak – sleepy during the winter and bustling during the long, warm days of summer. There are 10 laboratories at NRS that include one recently refurbished wet lab which hosted both TNA activities: Intercomparison of instruments for carbonate system measurements (INTERCARBO) and In-situ comparison of nitrate sensors (NitrateComp).
INTERCARBO was a week-long international activity led by Lauri Laakso from the Finnish Meteorological Institute (FMI) who was joined by colleagues from Finland, Germany, Italy, and France. In sum, there were nearly 20 instruments that measured different variables of the carbonate system: carbon dioxide, pH, and total alkalinity. The goal of the activity was to compare measurements made by different labs using different sensors on the same seawater samples. During the activity, measurements using the various instruments were carried out in 1 m3 tanks that were filled with seawater at salinity 5, 20, and 35 and carbon dioxide values at approximately 200, 400, and 800 parts per million (ppm). The measurements were made on seawater at 10 °C as well as 20 °C. The lab air temperature was held at the same temperature as the seawater temperature, so the conditions in the lab for the first half of the week were quite cool! In all, the group managed to create and make measurements on 17 unique combinations of salinity, temperature, and carbon dioxide concentrations! Most nights included a group dinner in the meeting room at NRS which was followed by late night measurements in the wet lab!
During INTERCARBO, the NitrateComp TNA activity began with a visit from Mario Esposito from GEOMAR Helmholtz Centre for Ocean Research in Kiel, Germany. This activity, which is six months in length, installed two different types of sensors for the measuring nitrate – an important nutrient for algae in the ocean. The two sensors that were installed were a miniature lab-on-a-chip nitrate analyzer and an optical nitrate sensor called an OPUS (manufactured by TriOS). The sensors were mounted in a seawater tank continuously filled from a 60 m intake pipe in the Oslo Fjord. In addition to measuring nitrate, salinity and temperature is also being continuously measured. Surface seawater from the Oslo fjord will also be measured later in the activity to test the performance of the two sensors during spring/summer when biologically activity is high and nitrate concentrations are expected to be more dynamic.
Please visit the TNA page for the NIVA Research Station for more information.