SFB754 Moorings 2006-2018

lmost all long-term moored observations of the SFB 754 were conducted in the tropical Atlantic between the equator and 18° N, except for one mooring that was deployed in the tropical South Pacific (see Table C4). Moorings were typically equipped with instruments recording pressure, temperature, conductivity, dissolved oxygen and current velocity. The moorings at 17.6° N, 24.2° W which have been deployed in the same location for several periods were additionally equipped with biogeochemical sensors recording variables such as partial pressure of CO2 (pCO2), fluorescence, and particle fluxes. Instruments with pressure, temperature, conductivity and oxygen sensors were calibrated in situ immediately prior to and after a mooring deployment period by attaching them to the CTD frame during CTDO casts. Correction terms were then developed from the difference between the sensor readings and the calibrated CTDO data during several minute long calibration stops. These correction terms were then applied to the full deployment periods. This ensured best data quality with recognition of potential sensor drifts and also allowed for the estimation of calibration and measurement errors (Hahn et al. 2014, Bittig et al. 2018, Berx et al. 2019). Moored Acoustic Doppler Current Profiler bin depths were corrected using the sound speed at instrument depth following the approach by Shcherbina et al. (2005). Velocities were not corrected, but respective measurement errors were assumed as described in Hahn et al. (2014). For all instruments within a mooring that did not record pressure, full deployment pressure time series were estimated by linearly interpolating between the instruments having a pressure sensor.