BEPSII Science Plan 2025–2035

1. Introduction

Sea ice is more than frozen ocean water: it is a dynamic, biogeochemically active interface between the ocean and atmosphere that regulates exchanges of gases, nutrients, mass, and energy across the polar regions. These processes underpin unique ecosystems and contribute to global biogeochemical cycles. As the Arctic and Antarctic undergo rapid environmental change, sea-ice habitats are shrinking, thinning, and transforming, with cascading consequences for climate, ecosystems, and societies.

Since its inception, BEPSII has built a vibrant international community dedicated to understanding the biogeochemistry of sea ice and its role in the Earth system. Over the past decade, BEPSII has:

• coordinated field and laboratory intercalibration efforts,
  
  

• advanced methods and best practices for sea-ice biogeochemical observations,
  
  

• produced influential syntheses and datasets that underpin model development,
  
  

• and actively engaged with early-career researchers (ECRs) and policymakers.
  
  

Despite these efforts, major challenges persist: Observations remain sparse and uneven; process-level understanding is still fragmented; and representation of sea-ice biogeochemistry in Earth System Models is only just beginning. At the same time, rapid advances in autonomous technologies, data science, and international initiatives (e.g., Antarctica InSync, the forthcoming 5th International Polar Year in 2033) create unprecedented opportunities.

The BEPSII Science Plan 2025–2035 lays out our roadmap for the next ten years. Our goals are to:

1. Consolidate and expand methodologies for consistent and high-quality data collection.
   
   

2. Harness new technologies for autonomous, large-scale, and multi-parameter observations.
   
   

3. Strengthen global data collation, accessibility, and FAIR standards.
   
   

4. Advance understanding of small- and large-scale processes through coordinated studies.
   
   

5. Improve representation of sea-ice biogeochemistry in models across scales.
   
   

6. Synthesize knowledge to address “big picture” questions, including climate interventions.
   
   

7. Communicate the vulnerability of the sea-ice ecosystem to stakeholders, policymakers, and the public.
   
   

The following sections outline the scope and activities of BEPSII’s seven task groups (TGs), which form the backbone of our scientific coordination.

2. Task Groups

TG1. Methodologies (Karley Campbell and Daiki Nomura)

Observations over recent decades suggest that sea ice plays a significant role in global biogeochemical cycles, providing an active biogeochemical interface at the ocean-atmosphere boundary. However, a pressing need exists to perform methodological inter-comparison experiments in sea ice in order to obtain reliable measurements of basic biogeochemical properties. With newly emerging techniques and pressed by rapid changes in the sea ice environment, the time has come to evaluate and improve our approach to studying sea-ice systems. 

In 2016, the Scientific Committee on Oceanic Research (SCOR) launched Working Group 152 on Measuring Essential Climate Variables in Sea Ice (ECV-Ice). The working group conducted inter-comparison exercises in the sea ice area during several campaigns and involving different facilities (e.g., Saroma-ko Lagoon, Cambridge Bay, MOSAiC, Roland Von Glasgow Air-Sea-Ice Chamber), and designed and coordinated new experiments for sea ice melting treatment, sea ice primary production, light, gases, and gas flux measurement over the sea ice. After finishing ECV-Ice (end of 2023), the BEPSII methodological task group was established to continue the above activities.

Our ultimate goal is to provide the international community with a comprehensive manual of best practices (e.g., standard operating procedure: SOP) for sea-ice biogeochemistry based on the results of past and future inter-comparison exercises. Furthermore, we will establish the effectiveness of metadata/documentation file format and structure, communication tools between field scientists and modellers, and new designs for field campaigns such as IPY and sea ice tank experiments. These tasks will directly serve a long-term community goal of understanding variations in polar marine environments severely affected by ongoing global change.

TG2. New Technologies (Klaus Meiners and Emiliano Cimoli)

Measuring biogeochemical processes at the air–sea-ice–ocean interfaces is inherently complex, especially in polar regions where harsh environmental conditions and logistical challenges significantly hinder research efforts. These processes often require the measurement of multiple parameters across different physical states—solid ice, liquid water, and gaseous air—which must be captured simultaneously to provide meaningful flux estimations and a mechanistic understanding of coupled systems. Achieving this has historically been challenging, especially given the heterogeneity of sea ice and the limitations of traditional sampling methods.

However, the rapid advances in sensor technology present unprecedented opportunities to overcome these challenges and maximize the efforts of the community in unique ways. Modern autonomous systems (e.g., under-ice buoys), underwater and aerial unoccupied vehicles (e.g., ROVs, UAVs, and drones), ice-tethered observatories, and in-situ or ship-borne marine sensor arrays now demonstrate the ability for concurrent and continuous acquisition of critical parameters across increasing spatial and temporal scales. Animal-borne sensor data have also emerged as a complementary technology for oceanographic and biological studies, particularly in ice-covered regions that are difficult to access and are extremely data-poor. These tools, if properly utilized, can drastically reduce long-term monitoring costs while enabling higher sampling frequency, extended durations, and improved spatial resolution and accessibility in periods that were previously extremely data-poor. Simultaneously, the emergence of big data from new satellite platforms (e.g., hyperspectral and thermal imaging) and advances in AI algorithms provide powerful opportunities to extrapolate in situ observations to broader spatial scales and link local processes to regional and global phenomena.

As a research community, there is an urgent need to synthesize, evaluate, and advance these emerging approaches to maximize their potential. Task Group 2 of BEPSII is dedicated to addressing this need by routinely summarizing the latest technological advancements from a biogeochemical parameter-specific perspective. Through quarterly information sessions, targeted literature and perspective reviews, and planned intercalibration exercises at upcoming field schools, such as Saroma 2026 in Japan, the community can collectively evaluate new tools, refine methodologies, and promote the adoption of advanced monitoring technologies. Strategic linkages with expert groups (e.g., SCAR-ASPeCt) will further enable cross-disciplinary knowledge transfer and support the development of collaborative proposals for infrastructure investment and shared access to existing platforms. These efforts aim to build a robust network of state-of-the-art tools, particularly in preparation for major international initiatives such as Antarctica InSync (2027–2030) and the IPY 2033. By pooling expertise and resources, the community can accelerate progress in polar research, expand observational capacity, and train the next generation of sea-ice biogeochemical scientists while generating high-quality datasets essential for understanding processes and advancing modelling efforts.

TG3. Data Collation and Reviewing (Jacqueline Stefels and Bruno Delille)

Despite significant progress, our understanding of marine biogeochemistry in the sea ice zone is still limited. Observations are sparse due to technical and logistical limitations, and satellite remote sensing is only appropriate for the retrieval of a limited number of sea-ice biogeochemical parameters. In addition, not all available historical observations have been conducted in comparable ways, nor compiled into consistent and easily-accessible databases. As a consequence, the representation of sea-ice zone biogeochemical processes in regional and Earth System Models (ESMs) remains extremely simple, and our confidence in understanding either the current importance of these processes or how they will respond to climatic change is limited.

Since the founding of BEPSII, considerable efforts have been put into collating and reviewing data on sea-ice-associated biogeochemical parameters. This implies the evaluation of sampling methods, the conversion of data into comparable and consistent databases, and the review of observed patterns, with the aim of producing consistent and reproducible climatologies, thereby improving the usefulness and efficacy of observational data for models.

Examples of past data collations are: Chlorophyll a in Antarctic pack ice (Meiners et al. 2012), Iron in Antarctic ice (Lannuzel et al. 2016, Tedesco and Lannuzel, 2023), Microalgal community structure and production in Arctic and Antarctic sea ice (van Leeuwe et al. 2018), Macronutrients in Antarctic land-fast sea ice (Henley et al. 2023), and net community production in Antarctic sea ice (Dalman et al. 2024). Efforts currently in progress are on Arctic and Antarctic air-ice CO2 fluxes, Arctic sea-ice chlorophyll-a and macronutrients, Arctic and Antarctic sea-ice DIC/TA, and 18O-H2O. 

As a community of researchers, BEPSII continues to pursue its initial work on historical data collation and analysis. Through our network, the international community is invited to contribute to data collations, which result in co-authorship of the final publication. 

Foci for the coming years are:

• Continue to pursue the initial work on historical data collation and analysis, differentiated into fast vs pack ice and Arctic vs Antarctic. A list of activities and responsible persons is given in the annex.

• Extend collations to new ice types: thin ice, frazil ice, and platelet ice.

• Improve the functionality of the data collation protocol to support both coordinated data reporting of International large-scale efforts, such as Antarctica In-Sync and the IPY, as well as data reporting of specific collation activities. The current protocol compiles raw data into the ASPeCT-bio spreadsheet, followed by the “BEPSII ice-core analyzer”, a Matlab routine to analyze and graph the data. With current new and online tools for data evaluation, there is a need for a simpler and more versatile format that can be used in different analytical languages, such as R or Python. 

TG4. Process Studies and Coupling with Neighbouring Environments (Sebastien Moreau and Ilka Pekeen, Pat Wongpan (rotating))

One of the objectives of BEPSII is to investigate the coupling of sea ice biology and biogeochemistry with its neighbouring environments and across its different interfaces, for a better understanding of biogeochemical cycles. Biological transformation processes, including at the atmosphere-sea ice-ocean interface, are assessed by determining the rates of key species, e.g., for primary production and gas production/fluxes. For the analyses of sympagic-pelagic coupling, the role of sea ice melt on the stratification of the upper ocean and its nutrient source will be investigated. The configuration and evolution of the coastal icescape, including sea ice, fast ice, and icebergs, modify the physical and biogeochemical properties of the ocean. In particular, the role of coastal fast ice for seeding phytoplankton - both in the Antarctic and the Arctic - will be investigated. The influence of freshwater ice, dirty ice, cryosphere-ocean interactions, and coastal processes, including freshening and their impact on sea ice properties, such as permeability and ecosystem, will be studied within the land-sea ice continuum. The coupling with higher trophic levels will highlight the importance of sea ice for these groups but also show the role of biogeochemical feedbacks of the higher trophic level, for e.g. phytoplankton blooms.  Deep-sea export and cryo-benthic coupling, particularly in shelf regions, will be studied to represent the effects of sea ice changes on benthic communities. For the export of carbon to the deep sea, the coupling between the biology of sea ice and the importance of mineral precipitation (e.g. gypsum) will be investigated using data from sediment traps, EIAs, and BGC Argo floats.

TG5. Processes Across Scales (Nadja Steiner and Giulia Castellani)

Primary production, ice algal standing stocks, and other biogeochemical processes are highly variable throughout the Polar regions and exhibit various levels of sensitivity to changing environmental conditions. To understand the effects that climate change and other environmental changes have on polar ecosystems both qualitatively and quantitatively, we need to parameterize and run models with key biogeochemical processes and interactions on larger scales. This can be achieved by large-scale model development and simulations, and by comprehensive data compilations supporting gridded data products. It is the aim of TG5 to coordinate these efforts to produce current and future projections of Arctic and Southern ocean biogeochemical variables in and near sea-ice, as well as compile large-scale maps from existing sea-ice biogeochemical data.

One example is the production of prognostic model outputs for future sea-ice algal productivity. This can be achieved by implementing sea-ice algae and other sea-ice biogeochemical variables into regional and global models that can simulate present and future scenarios. For CMIP7, sea-ice biogeochemical output variables have been identified in the hope of encouraging implementation and simulations with sea-ice biogeochemistry. Within TG5, we will also take part and coordinate model intercomparisons with the aim of producing a synthesis of models available on large scales. Connections with other groups (e.g., CAMAS) complement the work done within TG5.

TG5 also aims at improving the accessibility and applicability of sea-ice biogeochemical model output, including projections for a large audience. This includes efforts/projects with Arctic Indigenous peoples. For example, we aim to relate sea-ice conditions and sympagic production to habitat suitability assessments relevant to harvesting activities for communities living in the Arctic.  

Cross-cutting task team on Light. Light is a key driver for ecosystem phenology. Therefore, changes in light availability can have a significant impact on Arctic primary production. Within BEPSII we established a new task group on light, which will be coordinated by TG5 and will act across TGs. This cross-cutting task team will aim to collect and summarise existing data and existing knowledge on light transmission through sea ice. This includes data compilation to create large-scale maps of under-ice light that can be used for model evaluation. Another goal is to revise parameterizations for light transmission through sea ice used in different sea-ice models, including CMIP6. Finally, this cross-cutting TG aims at evaluating the implications for ecosystems of a changing light field as a consequence of sea ice reduction.

TG6. Syntheses (Lisa Miller and Odile Crabeck)

By integrating the activities of task groups 1 through 5, we aim to produce a coherent understanding of sea-ice biogeochemistry, its functions and ongoing changes, as well as its critical role in the Earth system. Task group 6, dedicated to Syntheses, is intended to provide comprehensive assessments of current knowledge and identify unresolved “big picture” questions. This task group bridges all the others but focuses notably on the dissemination of our growing understanding and knowledge to scientists studying other Earth system components and policy-makers who must consider the broad implications of their decisions and agreements. 

Key to such an integrated perspective is a full-system conceptual model of the role of sea ice within the vertical profile of the planet’s surface active layers, extending from the stratosphere to ocean sediments. By understanding these interconnections, we can deliver concrete warnings and guidance on the potential consequences of changes within the system, including the impacts of climate change, the implications of climate mitigation or intervention policies, and the repercussions of local development or conservation activities. Thus, key activities of this task group include: major reviews that integrate across disciplines; policy-relevant syntheses and briefings in digestible, plain language; and evaluations of intervention strategies to restore sea ice and/or the global climate.

Example specific activities (for implementation plan annex):

• Position analysis on “Implications of Antarctic sea-ice changes for biogeochemical cycles and ice-associated ecosystems”. Ongoing, intended for submission to Nature Communications or a similar journal. Lead: K. Meiners

• Evaluations and assessments of climate intervention proposals. Assure that sea-ice biogeochemistry is taken into consideration in sea-ice restoration, marine carbon dioxide removal, and radiative balance modification activities. Collate community reviews of climate intervention assessments, such as the Arctic Sea Ice Roadmap prepared by Ocean Visions, and  Climate Intervention Expert Assessments prepared by the University of the Arctic. Contribute to the development of governance structures for climate intervention research in collaboration with international bodies, such as the World Climate Research Programme and local communities. 

• An integrated analysis of the connections between ice physics and ecosystem structure in carbon export via both physical and biological pumps, based on a new data collation on carbon content and export from TG3. In close collaboration with ASPeCt. 

• Development of ecosystem health indices. Define indicator species and thresholds for biomarkers and key drivers in different sea-ice regions. 

• Workshops on best practices for collaborations between modelers and observationalists. Evaluation of lessons learned from recent major expeditions in polar regions: what worked and what did not; how can communications between groups be improved to assure that different needs and priorities are met.  

• Cross-cutting task team on Light. Integrating activities within all other task groups targeting light measurements, processes controlling light fields, numerical parameterizations, and implications of changing light.

• Commentary on environmental ethics of our work, with regard to carbon footprints and environmental impacts, led by early career scientists.

TG7. Outreach and Communication (Letizia Tedesco, Emelia Chamberlain, Laura Dalman, Josephine Rapp, Eeva Eronen-Rasimus)

In response to changing sea-ice conditions, human activities such as subsistence harvesting, commercial fisheries, tourism, resource extraction, and shipping have been changing and will continue to do so. BEPSII wants to advocate for the sea-ice ecosystem and aims to communicate sea-ice changes and consequences not only to scientists but also to a wider audience.

BEPSII is committed to guiding stakeholders and policymakers through its involvement in the Arctic Council’s Arctic Monitoring and Assessment Program (AMAP), the International Arctic Science Committee (IASC), and the Scientific Committee on Antarctic Research (SCAR). BEPSII also contributes by producing policy briefs and actively organizing and participating in international climate forums, including the Conference of the Parties (COP) conferences.

Building capacity, BEPSII strongly supports early-career researchers (ECRs) through initiatives such as biennial exchange awards, field schools, educational videos, and travel support to annual meetings. Also, BEPSII encourages ECRs to take on leadership roles in synthesizing data and research within their areas of expertise, all while receiving mentorship from senior scientists. Additionally, BEPSII is committed to making science accessible to younger (elementary to high school) audiences through initiatives like publications in Frontiers for Young Minds.

The dissemination of BEPSII outcomes targets both the scientific community and broader audiences. These outcomes are widely shared via the BEPSII mailing list and website (https://www.bepsii.org). BEPSII is also expanding its engagement through a dedicated YouTube channel. 

In addition to continuing the activities mentioned above, BEPSII aims to broaden its outreach efforts over the next ten years by:

• Organizing a quarterly BEPSII newsletter and seminar series to foster ongoing scientific discussions and to reach out to anyone with a scientific interest in sea ice (from scientists to policymakers).

• Increasing communication within the scientific community by hosting open meetings for the different BEPSII TGs.

• Strengthening ties with funding agencies and other networks to enhance research collaborations (i.e., SCAR, CLiC, SOLAS).

• Increasing the visibility of BEPSII members and activities by producing short videos, interviews, and profiles of researchers to share on the website and over social media, and launching an Instagram profile to engage the general public.

• Collaborating with other outreach networks and exploring funding opportunities, such as the United Nations (UN) Decade for Cryospheric Sciences initiative.

3. Implementation

BEPSII will achieve this plan through:

• Annual meetings with strong ECR leadership.
  
  

• Special issues, conference sessions, and workshops.
  
  

• Collaborative proposals for funding and infrastructure.
  
  

• Advocacy and coordination for Antarctica InSync and IPY2033.
  
  

• Active engagement with underrepresented communities and global networks.