Carbon - trace metal interactions in the oceanic twilight zone

The oceanic Biological Carbon Pump (BCP), consisting of surface production and subsequent sinking and remineralisation of organic matter, is a crucial component of the global carbon cycle. In addition to carbon, organic matter is composed of a wide range of nutrient elements, including trace metals such as iron (Fe), which can become limiting in surface regions of the ocean, exerting a significant control on production and ultimately the efficiency of the BCP. Although surface ocean interactions between the trace metal and carbon cycles have been relatively well studied, little work has been performed on the (de-)coupling of these cycles within the oceanic mesopelagic (the so-called 'twilight zone'). For example, carbon is remineralised differently to trace metals such as Fe, while the possibility for trace metal availability to influence microbial metabolism in the twilight zone is almost completely unexplored. Ultimately such processes could have a strong influence on atmospheric CO2 through multiple feedbacks, including influences on the depth of carbon remineralization, or the potential for different nutrients to become limiting either locally or, through interactions with the large scale oceanic circulation, remotely and/or globally.

COMICS will ultimately result in improved predictions of future ocean carbon storage, hence contributing essential knowledge for evidence based policy-making. This project has been designed to provide an immediate and direct benefit to the ongoing development of the NERC-Met Office UK Earth System Model (ESM) which is the UK's platform for future IPCC assessments. COMICS will establish a pipeline for new insights from our in situ work to be translated through into recommendations for novel model parameterisations for a key component of the global carbon cycle, which will then be incorporated in the UK-ESM. This will build on work currently funded under the NERC Process Based Model Evaluation programme, which is part of the UKESM development strategy. To ensure that the results from our observational programme are translated into practical parameterisations for climate models, Prof Colin Jones (Head of the UKESM project) will sit on our project advisory board.

In addition to the Met Office, we have engaged stakeholders in Cefas (an executive Defra agency) which is responsible for delivering evidence-based advice on marine management issues. Our proposed work on marine environment modelling and predicting the marine impacts of climate change are directly relevant to Cefas. COMICS will ensure a direct link to Cefas/Defra through the inclusion on our programme advisory board of Dr Robert Thorpe (Fisheries Scientist) who will also provide a route to policy makers via the Marine Climate Change Centre.

COMICS will contribute to the UK's international standing, and capacity building in developing nations. One output of this project will be computationally efficient new parameterisations for carbon remineralisation which can be incorporated into any suitable global biogeochemical climate model. COMICS thus has the potential to influence future climate models at the international level. We will also contribute to capacity building in developing nations by proposing researcher exchange programmes and mentoring development of early career researchers.

COMICS also includes a programme of public engagement activities, targeting both the general public and the next generation of marine scientists. These activities aim to increase awareness of the importance of ocean carbon uptake for regulating Earth's climate in an era of increasing greenhouse gas emissions.

These goals will be achieved through a dedicated impact effort, through dedicated staff time from NOC's communications office and the COMICS programme manager, with input from all members of the COMICS team.

Our impact programme includes funds for: a targeted stakeholder event that will be held at the end of year 3 in London to present our results from the specific standpoint of policy makers; design and distribution of glossy literature aimed at stakeholders and the general public; development of a programme website including professional graphic design; development of display materials for public events, such as science fairs.

Proposed additional impact activities for which we do not request NERC funds include: a Royal Society scientific programme meeting to which both stakeholders and the broader academic community will be invited (to take place in year 4); a collaborative researcher exchange programme with South African colleagues via the Newton Fund; supporting development of early career researchers from developing countries through the POGO fellowship scheme; daily cruise blog from on board the ship; Twitter feed (#comicscarbon), including two live Twitter Q&A events during the cruises; articles aimed at the interested public in Planet Earth; editorial feature in a popular science magazine; regular media
releases associated with cruises, journal articles, events etc.