On Using Lagrangian Drift Simulations to Aid Interpretation of in situ Monitoring Data

The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fmars.2021.666653/full#supplementary-materia

Extreme Flood Impact on Estuarine and Coastal Biogeochemistry: the 2013 Elbe Flood

Within the context of predicted and observed increase in droughts and floods with climate change, large summer floods are likely to become more frequent. These extreme events can alter typical biogeochemical patterns in coastal systems. The extreme Elbe River flood in June, 2013 not only caused major damages in several European countries, but also generated large scale biogeochemical changes in the Elbe Estuary and the adjacent German Bight. Due to a number of well documented and unusual atmospheric conditions, the early summer of 2013 in Central and Eastern Europe was colder and wetter than usual, with saturated soils, and higher than average cumulative precipitation. Additional precipitation at the end of May, and beginning of June, 2013, caused widespread floods within the Danube and Elbe Rivers, as well as billions of euros in damages. The floods generated the largest summer discharge on record within the last 140 years. The high-frequency monitoring network in the German Bight available within the Coastal Observing System for Northern and Arctic Seas (COSYNA) captured the flood influence on the German Bight. Monitoring data from a FerryBox station in the Elbe Estuary (Cuxhaven) and from a FerryBox platform aboard the M/V Funny Girl Ferry (traveling between Büsum and Helgoland) documented the salinity changes on the German Bight, which persisted for about 2 months after the peak discharge. The flood generated a large influx of nutrients, dissolved and particulate organic carbon on the coast. These conditions subsequently led to the onset of a chlorophyll bloom within the German Bight, observed by dissolved oxygen supersaturation, and higher than usual pH in surface coastal waters. The prolonged stratification also led to widespread bottom water dissolved oxygen depletion, unusual for the south eastern German Bight in the summer

Exploring ocean biogeochemistry using a lab-on-chip phosphate analyser on an underwater glider

The ability to make measurements of phosphate (PO43–) concentrations at temporal and spatial scales beyond those offered by shipboard observations offers new opportunities for investigations of the marine phosphorus cycle. We here report the first in situ PO43– dataset from an underwater glider (Kongsberg Seaglider) equipped with a PO43– Lab-on-Chip (LoC) analyser. Over 44 days, a 120 km transect was conducted in the northern North Sea during late summer (August and September). Surface depletion of PO43– (<0.2 μM) was observed above a seasonal thermocline, with elevated, but variable concentrations within the bottom layer (0.30–0.65 μM). Part of the variability in the bottom layer is attributed to the regional circulation and across shelf exchange, with the highest PO43– concentrations being associated with elevated salinities in northernmost regions, consistent with nutrient rich North Atlantic water intruding onto the shelf. Our study represents a significant step forward in autonomous underwater vehicle sensor capabilities and presents new capability to extend research into the marine phosphorous cycle and, when combined with other recent LoC developments, nutrient stoichiometry

Intertidal regions changing coastal alkalinity: The Wadden Sea-North Sea tidally coupled bioreactor

In this study, we successfully implemented a total alkalinity (TA) analyzer in a flow‐through setup, in combination with a FerryBox. The high‐frequency (10 min) measurements along our ship's route revealed that in coastal systems, where carbon fluxes are dynamic, TA can differ significantly (by up to 100 μmol kg−1) between the nearshore and adjacent coastal regions. Even though this study could not account for the net yearly TA production in the coastal region, it demonstrated that there was a seasonal increase in TA of 100–150 μmol kg−1 in coastal waters of the North Sea, equivalent to TA production of 11.7–26.8 mmol m−2 d−1 during the spring and summer months. This seasonal change could not be accounted for by riverine contributions, but instead was probably related to seasonal organic matter production and processing in coastal and nearshore regions. Bottom sediments and the tidally coupled biogeochemical reactor between coastal (North Sea) and nearshore (Wadden Sea) regions are mediating this TA change, and the ~ 4 months lag between the seasonal increase in alkalinity and the peak organic matter production could be explained by the supply of (labile) organic matter and its temperature‐dependent remineralization via both aerobic and anaerobic pathways.publishedVersio

Nitrogen turnover in the Ems estuary 2020

We measured dissolved and particular inorganic nitrogen and dissolved nitrous oxide concentration in the Ems estuary (Germany). The sampling campaign was conducted on two consecutive days in June 2020 (11.06.2020– 12.06.2020) on board of the German research vessel Ludwig Prandtl. Water samples were taken approximately every 20 min during ebb tide from the North Sea around the island Borkum upstream to Papenburg. The discrete water samples were used to measure dissolved inorganic nutrient, nitrate stable isotope composition, suspended particular matter (SPM) concentration, particular carbon and nitrogen content of SPM and nitrogen stable isotope composition of SPM. An onboard membrane pump provided the on-line in situ FerryBox system with water from 2 m below the surface. It continuously measured oxygen, salinity, and temperature during our cruise. A N2O analyzer coupled (Model 914-0022, Los Gatos Res. Inc., San Jose, CA, USA) with a sea water/gas equilibrator using off-axis cavity output spectroscopy continuously detected dry mole fraction of dissolved nitrous oxide along the estuary. The aims of the study were 1) to investigate spatial dynamics in nitrogen turnover processes along the Ems estuary, 2) to identify their relation to nitrous oxide production and 3) to unravel controlling factors of the nitrogen circle

FerryBox-integrated membrane-based pCO2, temperature and salinity sensor measurements from Cargo Ship MAGNOLIA SEAWAYS (August/September 2019)

The submitted dataset contain surface seawater partial pressure of carbon dioxide (pCO2) values measured with Kongsberg Contros/4H-Jena HydroC-FT membrane-based sensors. These sensors were integrated on the FerryBoxes installed on commercial vessels travelling in the North Sea and maintained by the Institute of Coastal Ocean Dynamics at the Helmholtz-Zentrum Hereon, Germany. The pCO2 data were reprocessed from the raw data and corrected for sensor post-calibration where this was available. The instrument produces a result every second. 20-second averages are used for calculations and reported. Temperature and salinity results are also provided where available. These were measured from the underway with Falmouth Scientific Instruments / Teledyne Instruments sensors also integrated with the FerryBox. The sensors were regularly maintained and occasionally replaced. Each sensor replacement results in a new dataset within this publication series

FerryBox-integrated membrane-based pCO2, temperature and salinity sensor measurements from Cargo Ship LYSBRIS SEAWAYS (December 2015- December 2016)

The submitted datasets contain surface seawater partial pressure of carbon dioxide (pCO2) values measured with Kongsberg Contros/4H-Jena HydroC-FT membrane-based sensors. These sensors were integrated on the FerryBox installed on the commercial vessel Lysbris Seaways (DFDS Seaways shipping company) travelling in the North Sea and maintained by the Coastal Research group at the Helmholtz-Zentrum Geesthacht, Germany. The pCO2 data were reprocessed from the raw data and corrected for sensor post-calibration where this was available. The instrument produces a result every second. 20-second averages are used for calculations and reported. Temperature and salinity results are also provided where available. These were measured from the underway with Falmouth Scientific Instruments/ Teledyne Instruments sensors also integrated with the FerryBox. The sensors were regularly maintained and occasionally replaced

Ship-of-Opportunity, FerryBox-integrated, membrane-based sensor pCO2, temperature and salinity measurements in the surface North Sea since 2013

The submitted datasets contain surface seawater partial pressure of carbon dioxide (pCO2) values measured with Kongsberg Contros/4H-Jena HydroC-FT membrane-based sensors. These sensors were integrated on the FerryBoxes installed on commercial vessels travelling in the North Sea and maintained by the Institute of Coastal Ocean Dynamics at the Helmholtz-Zentrum Hereon, Germany. The pCO2 data were reprocessed from the raw data and corrected for sensor post-calibration where this was available. The instrument produces a result every second. 20-second averages are used for calculations and reported. Temperature and salinity results are also provided where available. These were measured from the underway with Falmouth Scientific Instruments / Teledyne Instruments sensors also integrated with the FerryBox. The sensors were regularly maintained and occasionally replaced. Each sensor replacement results in a new dataset within this publication series. The files are named using the ship name and date of the first measurement

FerryBox-integrated membrane-based pCO2, temperature and salinity sensor measurements from Cargo Ship HAFNIA SEA (January-October 2016)

The submitted datasets contain surface seawater partial pressure of carbon dioxide (pCO2) values measured with Kongsberg Contros/4H-Jena HydroC-FT membrane-based sensors. These sensors were integrated on the FerryBox installed on the commercial vessel Hafnia Sea (DFDS Seaways shipping company) travelling in the North Sea and maintained by the Coastal Research group at the Helmholtz-Zentrum Geesthacht, Germany. The pCO2 data were reprocessed from the raw data and corrected for sensor post-calibration where this was available. The instrument produces a result every second. 20-second averages are used for calculations and reported. Temperature and salinity results are also provided where available. These were measured from the underway with Falmouth Scientific Instruments / Teledyne Instruments sensors also integrated with the FerryBox. The sensors were regularly maintained and occasionally replaced