GEORGE will be at the ICOS Science Conference 2026, taking place on 15–17 September 2026 in Lund, Sweden and online.
We are convening a dedicated session on “Advancing marine CO₂ observations through next-generation sensors, integration and platform innovation”, which will take place on 15 September at 16:30-18:00.
The session brings together research infrastructures, projects and institutes working on autonomous marine CO₂ observations, from novel sensors and samplers to integrated observing platforms and operational networks such as ICOS, EMSO and Euro-Argo.
The conference registration remains open throughout the event. Read more and register here.
Parallel session 7: Advancing marine CO₂ observations through next-generation innovations
15.09. 16:30 – 18:00
Källarsalen
367: An autonomous lab-on-chip sensor for ocean carbonate system characterisation
Anthony Lucio, Wahida Bhuiyan, Martin Arundell, Allison Schaap, Pablo Trucco-Pignata, Stathys Papadimitriou, Socratis Loucaides
The ocean plays a central role in the global carbon cycle, currently absorbing ca. a quarter of anthropogenic carbon dioxide (CO2) emissions, which is having a significant impact on marine organisms. Constraining this uptake, and the associated changes in ocean carbonate chemistry, requires accurate, reliable and autonomous sensing technologies. Investigation of the marine carbonate system requires data from at least two of the four measurable carbonate parameters i.e., partial pressure of CO2, pH, total alkalinity (TA), and dissolved inorganic carbon (DIC). At present there is a lack of sensors that can provide the spatial and temporal requirements needed, and developing this technology is key to address knowledge gaps in our understanding of the global carbon cycle. To address this need, we developed a novel combined TA-DIC sensor based on lab-on-chip (LOC) technology, which offers miniaturisation and automation of high-performance reagent-based analytical techniques. An early prototype LOC TA-DIC sensor was successfully deployed and validated during a five-day mission on the Autosub Long Range in 2024.
This contribution will focus on our latest research and development efforts into LOC-based TA-DIC sensors (e.g., sensor operation, calibration/validation efforts, preliminary field tests, and learnt experience to-date of integrating these sensors onto gliders and floats). The work is being advanced within the EU-funded TRICUSO and UK-funded MaSCOt projects, where integration of LOC carbonate sensors on floats and gliders aims to strengthen sustained, high-quality observations of the marine carbonate system in support of European research infrastructures and the UK’s Future Marine Research Infrastructure (FMRI), respectively.
526: Estimating the bias of pH measurements from biogeochemical Argo floats in high latitude
Tobias Steinhoff, Cathy Wimart-Rousseau, Henry Bittig, Birgit Klein, Arne Körtzinger
The development of pH sensors for ocean applications has the potential to increase the observations of the marine carbon cycle by using biogeochemical Argo floats. In order to make them a suitable addition for the observation of ocean carbon dynamics, a thorough evaluation in different parts of the ocean is needed. Recently, Wimart-Rousseau et al. (2024) examined adjustment techniques for float-based pH measurements using data from a pH–O₂ float pilot array in the subpolar North Atlantic Ocean and highlighted biases among commonly used correction methods. Comparisons with independent discrete and underway pH measurements reveal discrepancies at the surface ocean suggesting that the target accuracy of 0.01 pH units for deriving surface ocean pCO₂ cannot consistently be achieved.
We further extend this analysis by evaluating uncertainties in float pH measurements from the same region using an expanded dataset that includes additional float observations as well as a larger set of independent reference measurements in the upper 2000 m. The results found similar offsets like those reported by Wimart-Rousseau et al. (2024) and further reinforce the conclusion that a single deep reference depth for pH correction is insufficient in the studied region.
We therefore propose including an additional independent pH reference near the ocean surface and adopting adapted correction strategies in dynamically complex regions such as the subpolar North Atlantic to improve quality control and enhance the reliability of air-sea CO2 flux estimates. This could lead to adjusted calibration routines, which need to be tested in the field during future studies.
92: Surface Slicks Decouple the Air–Sea CO₂ Gradient and Bias Flux Estimates
Mariana Ribas Ribas, Oliver Wurl, Edgar Fernando Cortés-Espinoza
Accurate quantification of air–sea carbon dioxide (CO₂) exchange requires resolving small-scale variability at the ocean–atmosphere interface. Still, most flux calculations assume vertically well-mixed boundary layers and rely on CO₂ partial pressures (pCO₂) measured meters above and below the sea surface. Here, we present results from a July 2024 field campaign in the German North Sea, where we deployed two observing platforms to examine how near-surface stratification influences CO₂ flux estimates. We measured the difference between oceanic and atmospheric pCO₂ (ΔpCO₂) at 100 cm above and below the surface (meter-scale interface) and at 20 cm (centimeter-scale interface), allowing a direct comparison between traditional and high-resolution methods.
Slicks are surface phenomena where capillary waves are damped by accumulated organic carbon. We identified Non-slick and Slick Scenarios with clear differences: under Non-slick conditions, both ΔpCO₂ approaches were similar, producing comparable CO₂ fluxes. In contrast, Slick Scenarios caused a persistent increase of more than 100 µatm in pCO₂ at 20 cm above the surface, decoupling the near-surface atmosphere from the meter-scale gradient. As a result, near-surface ΔpCO₂ exceeded the meter-scale estimate by more than 100 µatm, leading to significant differences in calculated CO₂ fluxes (up to −35.6 mmol m⁻² d⁻¹), which influenced both magnitude and direction. These findings show that slick-induced stratification can bias meter-scale flux calculations and emphasize the importance of centimeter-scale, high-frequency CO₂ measurements using innovative, non-intrusive sensors and integrated observing platforms. Accurately resolving near-surface ΔpCO₂ is essential for improving flux estimates and advancing next-generation marine CO₂ monitoring systems.
129: Measuring air-sea CO₂ fluxes using an innovative instrumented ocean gliders approach
Paco STIL, Louise DELAIGUE, Felix MARGIRIER, Rémi EMMETIERE, Tobias STEINHOFF, Socratis LOUCAIDES, Susan HARTMAN, Anita FLOHR, Andrew GATES, Laurent COPPOLA
Air-sea carbon dioxide (CO₂) exchange is a key variable of the Earth’s climate system. Over 2014-2023, the ocean is estimated to have absorbed 3.2 ± 0.4 GtC yr⁻¹, around one third of anthropogenic CO₂ emissions. Yet, substantial gaps persist between estimates based on global ocean biogeochemistry models and observation-based surface fCO₂ products, largely because in situ CO₂ measurements remain sparse and seasonally biased. These limitations are especially important at high latitudes, where fCO₂ reconstructions may overstate variability by up to ~30%. Expanding autonomous observations is therefore critical to reduce uncertainty in the ocean carbon sink. For the first time, wz deployed a Sea-Explorer glider (ALSEAMAR) integrating a membrane-based Pro-Oceanus Mini CO₂ sensor together with an acoustic wind sensor (Purpoise). This configuration enabled co-located measurements of the key variables (fCO2 and wind speed) needed to estimate air-sea CO₂ fluxes while simultaneously profiling the upper ocean to 1000 m depth. Field trials at the DYFAMED site (2024/2025) assessed Purpoise wind measurements against the DYFAMED buoy and evaluated Mini CO₂ observations through intercomparison with CTD-calibrated water-column measurements. A second deployment at the Porcupine Abyssal Plain site (June 2025) tested the near-surface performance of the Mini CO₂ sensor against the GO CO₂ system operated aboard RRS James Cook. Results demonstrate the technical feasibility of deriving glider-based air-sea CO₂ flux estimates and highlight the value of multi-sensor autonomous platforms to complement existing observing networks, improve spatiotemporal coverage, and ultimately reduce uncertainties in the global ocean carbon budget.
210: The CAPASOS instrument: ∆pCO₂ measurements from USVs
Ute Schuster, Witold Tatkiewicz, Luke Home
The CAPASOS instrument was designed and built at the University of Exeter (UoE, UK) to address the scientific community’s need for a low-cost, reliable system capable of collecting high-quality ∆pCO₂ data in remote ocean regions. The instrument consists of two main components: a dry compartment (the Core Unit) housing custom electronic PCBs, sensors, valves, pumps, etc.; and a wet section (the Equilibrator) where air–sea gas exchange occurs. A key design principle was minimisation of size and power consumption (3W average, up to 12W during start-up) to facilitate integration into Uncrewed Surface Vehicles (USVs). The result is a compact, flexible, and energy-efficient device suitable for autonomous deployments.
Within the framework of the HORIZON EUROPE GEORGE project, UoE and Offshore Sensing AS (Norway) collaborate to integrate the instrument into the SailBuoy surface uncrewed vehicle (USV). The integrated system was deployed from, and recovered again at, the Irish coast in July and August 2025, completing a 60-day mission, travelling over 1,000 km to and from the Porcupine Abyssal Plain – Sustained Observatory (PAP-SO). Post-recovery assessment of hardware and data analysis are continuing, with improvements being identified.
Current efforts focus on resolving identified issues and preparing for three planned deployments: 1) Northern Mediterranean Sea, summer 2026 (2nd demo in the GEORGE project), 2) Southern Ocean, autumn 2026 (TRICUSO project), and 3) Southern Ocean, autumn 2027 (TRICUSO project).
We will present details of the completed deployments and experiences of the development and improvement process.
Poster sessions
Explore GEORGE related posters below.
363 An interoperability challenge: The Porcupine Abyssal Plain ( PAP) demo mission as a test case for multi-RI marine carbon observations
Lucía Gutiérrez-Loza1,2,3*, Romain Cancouët4, Simo Cusi5, Delphine Dobler4, Clara C. Douglas4, Anita Flohr6, Thanos Gkritzalis7, Susan Hartman6, Aljaz Maslo5, Socratis Loucaides6, Janne-Markus Rintala8, Ute Schuster9
Coordinated and sustained efforts for ocean observing have become essential in the face of growing challenges for science, society, and policy making. Integrated ocean observations are crucial for understanding and monitoring ocean carbon dynamics, quantifying the global ocean carbon sink, and assessing the impacts of climate change in marine ecosystems.
A mission at the PAP Sustained Observatory in the northeast Atlantic during 2025/2026 has served as a demonstration of a state-of-the-art, multi-platform observing network. Leveraging the capabilities of three research infrastructures (RIs: ICOS, Argo, and EMSO), the setup includes co-located, multi-platform observations for a full characterisation of the marine carbonate system. This demo mission originated from the need to test and intercompare measurements in-situ, including both surface and at-depth observations, locally and regionally. Utilizing moorings, autonomous vehicles, and ship-borne observations, it was designed to enhance coordination and advance interoperability. As such, it offers an ideal setup for the intercomparison of instruments and methodologies, and for evaluating the long-term performance of the deployed technologies.
The PAP demo is the first of two missions organised under the GEORGE Project aiming to advance technology and interoperability towards an optimal array for marine carbon observations. Here, we showcase the PAP site as a test case for demonstrating multi-platform interoperability, advancing carbon observation methodologies, and contributing to the understanding and monitoring of global climate indicators like air-sea flux of greenhouse gases and ocean acidification. The lessons learned from these efforts will inform the development of more effective observational networks and ocean carbon monitoring strategies.
461 Deriving and assessing seawater pCO₂ (partial pressure of CO2) estimates from an Argo float across eddy‑scale and 10‑day sampling modes in the North Atlantic
Clara Celestine Douglas1*, Romain Cancouët1, Delphine Dobler1, Anita Flohr2, Lucía Gutiérrez-Loza3,4,5, Susan Hartman2, Socratis Loucaides2, Virginie Racapé6, Catherine Schmechtig7, Pablo Trucco Pignata2
The partial pressure of carbon dioxide in seawater (pCO2) is a key variable for climate science as it is vital for calculating estimates of air-sea CO2 fluxes. The Argo float array is a global network of profiling floats that provide continuous in situ, depth-resolving measurements of the oceans. However, there is currently no operational way to obtain direct measurements of pCO2 from these platforms. Presently, floats equipped with pH sensors can be used to estimate pCO₂ by combining interpolation methods (to calculate total alkalinity) with carbonate‑system calculations. With pCO₂ and wind reanalysis products, air-sea CO₂ fluxes can be derived. Meanwhile, the development and testing of pCO2 sensors and acoustic wind sensors for Argo floats is ongoing through the EU GEORGE and TRICUSO projects. These will improve calculations of flux estimates and provide validation for current methods.
A pH-equipped float was recently deployed at the Porcupine Abyssal Plain Sustained Observatory (North Atlantic) as part of GEORGE, initially profiling on a daily basis and circling an eddy for over a month. The results of Delayed Mode Quality Control (DMQC) processing of the float’s dissolved oxygen and pH measurements will be presented, with comparison to other in situ measurements. Estimates of pCO2 will also be presented alongside an assessment of uncertainties. These uncertainties stem from the settings and methods used for the DMQC adjustments and derivation of pCO2. The product presented here will contribute to an inter-comparison of data derived from other GEORGE CO2 system sensors, supporting a multi-platform observing framework.
512 Assessment of the Baltic Sea ecosystem through the combination and technical expansion of European infrastructures
Gregor Rehder1,2*, Henry C. Bittig1, Michael Glockzin1, Nadja Kinski3, Sebastian Neubert1, Stefan Otto1, Bernd Sadkowiak1, Katharina Seelmann3, Max Steinberg1
Nearly two decades of data acquisition on DE-SOOP Finnmaid have considerably fostered our understanding of production and mineralization patterns in the Baltic Sea, leading to e.g. a pCO2 climatology, or a complete textbook on Baltic Sea biogeochemistry.
However, questions concerning processes below the surface, such as the role of deep Chla maxima or the depth of mineralization, have not yet been investigated in sufficient detail. Recent advances in using BGC Argo floats, enhanced with pCO2 measurement capabilities, demonstrate the potential for obtaining vertical information on the fate of carbon at depth. Combining data from Ship-of-Opportunities (SOOPs) and Argo profiling floats provides a more complete 4D understanding of carbon dynamics in the Baltic Sea. Data integration from both platforms helps to better (i) quantify CO2 air-sea flux, uptake and release, ii) track CO2 cycling below the surface, and (iii) understand the drivers behind their dynamics.
The Baltic Sea, with its strong salinity and redox gradients, is an ideal setting to investigate the coastal dynamics of other (non-CO2) greenhouse gases, and to test new instrumentation for the use in European Research Infrastructures. By installing state-of-the-art continuous CH4 and N2O surface water measurements as part of ICOS and setting up a test field for additional commercially available sensors and sensors developed as part of the Horizon Europe project GEORGE, we are attempting to improve the capacity for biogeochemical observations of greenhouse gases in coastal areas within the framework of ICOS, BGC-Argo, and JERICO.
Interested in other ocean-related sessions at ICOS Science Conference 2026?
Explore the sessions below.
Session 1: How big is the open ocean carbon sink?
Session 2: Marine Carbon Dioxide Removal – What have we learned and what are the emerging challenges for MRV confidence
Session 3: Blue carbon and seaweed: reforestation and cultivation
Session 4: Carbon cycling in the land ocean aquatic continuum
Session 6: Carbon cycle in the Mediterranean region: from the local to the regional scale
Session 20: Unmanned autonomous vehicles and proximal sensing in greenhouse gas research and monitoring