Helgoland 2025: Eddy Covariance Air-Sea CO2 Flux and Water-Side Measurements

Between June 1 and September 13, 2025, high-frequency eddy covariance and water-side sensors measured air-sea CO2 exchange and oceanographic conditions off the northern shore of Helgoland island. The dataset includes 10 Hz atmospheric measurements scaled to 10 m height, in-situ water CO2 and CTD data from a nearby site, and water current profiles from an ADCP. Air-side CO2 concentrations were supplemented by a nearby ICOS station located 800 meters from the primary measurement site.

Use Cases

• Quantifying net air-sea CO2 flux dynamics in a coastal North Sea environment using eddy covariance measurements.
• Analyzing the relationship between wind speed (U10), water-side pCO2, and CO2 exchange rates.
• Investigating the impact of biological fouling on sensor data quality by examining trimmed salinity records.
• Correlating high-frequency atmospheric turbulence data with concurrent water current profiles from the ADCP.
• Calibrating or validating regional carbon cycle models with co-located meteorological and hydrographic observations.

Strengths

• Provides concurrent, high-frequency (10 Hz) atmospheric and water-side measurements from a defined period (June 1 to September 13, 2025).
• Includes quality control procedures, such as the trimming of spurious salinity values and regular sensor maintenance by divers.
• Data is cross-referenced with an independent ICOS station (HEL) for air-side CO2 concentrations, adding validation.
• Released under a permissive CC-BY-4.0 license, facilitating reuse.

Limitations

• Column names and a precise row count are not provided in the available metadata, limiting immediate understanding of data structure.
• The dataset description is truncated mid-sentence regarding the ADCP collection interval.
• A period of biological fouling in late September to early October required data trimming, which may create gaps.

Provenance

Source

Bryce Van Dam. Associated with the Alfred Wegener Institute (AWI) via the MARGATE site.

Collection Method

Field measurements using eddy covariance systems, in-situ CO2 sensors, CTDs, ADCP, and supporting meteorological stations.

Time Range

2025-06-01 to 2025-09-13

Freshness

Last updated on 2026-03-18.

Geography

Northern shore of Helgoland island, southern North Sea. Specific coordinates for the ICOS station: Lat: 54.1804, Lon: 7.8833.