ALBERT

Description: LADCP measurements were performed on all research cruises that concentrated on open ocean areas (see Table C3) while on cruises that worked mostly in shallow waters, ocean current measurements by the shipboard ADCP (see section 4.1.8) were deemed sufficient. GEOMAR used a two-instrument configuration with two Teledyne RDI 300 kHz workhorse ADCPs mounted in down- and up-looking positions. Data collection and processing was performed according to recommendations in the GO-SHIP manual (Thurnherr et al., 2010).

Description: Ocean turbulence measurement programs were carried out during 22 cruises to quantify the dissipation rate of turbulent kinetic energy and infer rates of turbulent mixing (see Table C6). The used shipboard microstructure profiling systems 165 (MSS) were manufactured by Sea & Sun Technology and consisted of a profiler (MSS90-D, S/N 26, 32 and 73), a winch having 500-1000 m of cable and a data interface. All profilers were equipped with three microstructure shear sensors, a fast- response temperature sensor (PF07), an acceleration sensor and two tilt sensors as well as conductivity (Sea & Sun Tech.), temperature (Sea & Sun Tech.), pressure (Keller), turbidity (Seapoint) and oxygen sensors sampling with a lower response time. The profilers were optimized to sink at a rate of 0.5-0.6 m s-1. Standard processing procedures were used to determine 170 the rate of kinetic energy dissipation of turbulence in the water column (see Schafstall et al. (2010) for a detailed description). Additionally, during several autonomous glider missions, a microstructure probe was mounted to the top of the gliders. These probes (MicroRider) were manufactured by Rockland Scientific and carried two microstructure shear and temperature sensors as well as pressure, accelerometer and tilt sensors. The data processing is detailed in Foltz et al. (2020).

Description: CTDO measurements were acquired on the major research cruises performed as part of the SFB 754 or other projects . Seabird 911plus systems equipped with dual temperature-conductivity-oxygen sensors were employed. All systems had a 24-bottle water sampling rosette with 10 l Niskin bottles. On some cruises only 22 bottles were mounted to accommodate a lowered Acoustic Doppler Current Profiler for deep ocean current observations. Water sampling, processing, and calibration followed GO-SHIP recommendations (Swift, 2010; McTaggart et al., 2010; Uchida et al., 2010) and included the recommended steps Data Conversion, Sensor Time-Alignment, Creation of Bottle Files, Outlier Removal, Pressure Sensor Filtering, Conductivity Cell Thermal Mass Correction, Ship Roll Correction and Deck Offset Correction by Loop Editing, as well as Derivation of Calculated Properties. After these steps, conductivity and oxygen readings were calibrated against values determined with salinometry and Winkler titration , respectively. Finally, the downcast data was averaged over 1 dbar wide intervals. An independent upcast calibration was used to obtain calibrated CTDO values coincident with the discrete water samples.

Description: During the second funding phase (2012-2015) a new CTD system became available that could be deployed from a moving 185 ship. First a Teledyne Oceanscience UCTD and later a Teledyne Oceanscience Rapidcast system were acquired and deployed successfully on several cruises (see Table C8). They allowed for the sampling of water masses at high horizontal resolution (ranging from less than 1 km for the Rapidcast system to 10 km for deep UCTD casts) with good accuracy of the pressure, temperature, and conductivity sensors. Processing of the data involved mostly the fall-rate dependent correction of the thermal lag of the conductivity sensor and followed the approach described by Ullman and David (2014). Subsequently 190 the corrected data was calibrated against the calibrated coincident Thermosalinograph and the calibrated nearby CTD data. The typical accuracies of the final pressure, temperature, and salinity data are 1 dbar, 0.01 °C, and 0.01 g/kg, respectively.

Description: The SFB 754 also made a contribution to the global ARGO float program. In 2009, 2911, and 2014 several floats equipped with additional Aanderaa oxygen sensors were deployed off Peru to study the effects of mesoscale eddies on the flow field 200 and the water masses (see Table C10; Czeschel et al., 2018). A number of floats was deployed in the tropical Atlantic to accompany a tracer release experiment (see section 4.2.3). Additionally several of the cruises were used to deploy regular ARGO floats on behalf of the German Hydrographic Office.

Description: 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.

Description: Nutrient, transient tracer and N2O water column measurements

Description: Continuous measurements of the climate-relevant trace gases carbon dioxide (CO2), nitrous oxide (N2O), and carbon monoxide (CO) in the surface ocean and overlying atmosphere were conducted during 9 SFB 754 cruises (see Table C14) spanning the North, South and equatorial Atlantic, as well as the South and equatorial Pacific. To this end, laser spectroscopy-based gas analyzers coupled to air-water equilibration chambers were used. For details of the analytical systems the reader is referred to the descriptions provided by Arévalo-Martínez et al. (2013) and Arévalo-Martínez et al. (2019). All trace gas measurements were quality-controlled to achieve the international standards for marine CO2 (Bender et al., 2002), N2O (Bange et al., 2019), and atmospheric CO (Zellweger et al., 2019; to date there is no accepted standard for seawater measurements). The final quality-controlled data is available through the Surface Ocean CO2 Atlas (SOCAT, https://www.socat.info/) and the Marine CH4-N2O database (MEMENTO, https://memento.geomar.de/) as well as on Pangaea

Description: Particulate organic matter (POM) distribution in the water column as on several cruises determined after filtration onto pre-combusted, acid-washed GF/F filters (Franz et al., 2012a). Particulate organic phosphorus (POP) collected on GF/F filters was determined colorimetrically. Samples for phytoplankton pigment concentrations were collected by filtration of seawater from the CTD/rosette through GF/F filters, and stored at -80°C immediately after filtration. Transparent exopolymer particles (TEP) and Coomassie stainable particles were filtered under low pressure (〈 150 mbar) onto 25 mm Nuclepore membrane filters (0.4 μm pore size, Whatman Ltd.) and stained with Alcian Blue and Coomassie Brilliant Blue, respectively. Export flux of was characterized using surface-tethered sediment traps (Engel et al., 2017), with Particle Interceptor-Traps (PIT) following Knauer et al. (1979).

Description: Dissolved Organic Matter, Cell Abundance and Extracellular Enzyme Rates and Bacterial Production from several cruises and experiments from 2008-2018