Ecosystem functions controlled by sea ice and light in a changing Arctic (Eco-Light)

SUMMARY

The Arctic is warming more than twice as fast as any other region of our planet. This warming has led to quantifiable changes right across the Arctic; land, ocean and atmosphere. However, the most dramatic changes are possibly those associated with Arctic sea ice. For example satellite records have revealed a significant decrease in sea ice extent in all months, especially in summer. There has been a reduction in summer sea ice extent from about 7 million square kilometres in the late 1970s to around 3.4 million square kilometres in 2012; a reduction of over 50%. Time-series analysis of submarine records concluded that the mean thickness has declined by more than 40%, and taken together that these changes have led to a fundamental shift in the ice regime in the Arctic. The Arctic is no longer a region dominated by a thick multi-year ice (MYI), but it is a regime controlled by thinner, more dynamic, first year ice (FYI). In fact complex computer models predict that the Arctic Ocean is on track to become mostly ice free in summer within a few decades, if not earlier.

Our understanding of the functioning of the Arctic marine ecosystem has been overwhelmingly derived from a MYI setting, rather than the FYI dominated Arctic of recent years. As a result, our current state of knowledge of these processes and the validity of many of the parameterisations presently embedded in computer models becomes more questionable. For example, recent studies revealed that that the transition from MYI to FYI summer ice cover corresponds to an increase of 200% in light transmittance into the upper ocean. Light is one of the critical ingredients that controls primary production under sea ice, and in addition recent modelling studies have shown that the sea-ice algal blooms are triggered by light availability. Therefore if we are to understand and predict ecosystem function in this 'new Arctic', we must understand and correctly parameterise the light climate under this new FYI environment we find ourselves in today, and for the foreseeable future. To do this correctly we need a holistic approach that seamlessly brings biology, optics, sea ice and ocean physics, together with satellite remote sensing and cutting-edge modelling.

This programme, Eco-Light, does this by utilising the modelling and observational expertise of the United Kingdom and Germany to better understand the influence of changing Arctic sea ice on ecosystem function. This is achieved by observationally constraining and improving the parameterisations of processes of light transmission in this 'new' Arctic, and by doing so we will better understand its influence on ecosystem function. This information will be used to resolve euphotic depths for primary productivity, and to predict the effects of changing snow-ice-ocean constituents on the underwater light climate.

Eco-Light will undoubtedly produce a strong legacy for UK and Germany leadership in key aspects of Arctic observational science, ecosystem dynamics, and predictive modelling.

IMPACT SUMMARY

Arctic change presents opportunities, but it also presents regional and global challenges and risks. Although Germany and UK are not Arctic nations, both play a proactive role on international Arctic bodies, such as our observer status in the Arctic Council. Over the past 12 months policy makers, businesses leaders and philanthropists have all been involved in meetings dedicated to the Arctic. A good example is the White House Science Ministerial which brought together leaders from around the world, with the aim to expand joint collaborations focused on Arctic science. The Arctic has impact.

To ensure our programme's impact goes beyond catchy headlines we will work in close contact with our Partners, and with the UK and German Arctic Office, to ensure the widest dissemination, and the involvement of a broad range of stakeholders. We will implement a range of activities with the aim of achieving the greatest potential for knowledge dissemination and socio-economic impact. We list some examples below:

Press office network:
The press offices at BAS, UCL, and AWI have a wide expertise in communicating with the media and public, as well as assisting and training staff in doing so. In order to attain a broader communication strategy, we will build on our established working relationship between our institutions. By doing so we are able to keep our press offices fully abreast of our project, and to facilitate communication to a wider audience, as well to co-ordinate 'on message' media activities. We appropriate we will actively pursue a reputable scientific journalist (BBC or similar) to participate and record our cruise and scientific discoveries.

Workshop
In the later stages of our project we will run a 2-day international impact workshop on Ecosystem function in the Arctic. Beside our international invitees we will provide dedicated space for key UK and German modelling and observational groups. This workshop will consolidate current understanding and include the new insight from this project, and identify the pathways to incorporating the new parameterisations in earth system models.

Outreach
Wider interest groups include school children, students and the general public. We will engage with them via outreach channels available to BAS, UCL, and AWI, including the press offices, websites and publications such as NERC's Planet Earth magazine, and presentations to the local community. Our cruise blogs will be of particular interest, as will our real time imagery from our autonomous platforms. We will use the knowledge gained within our project to develop new and innovative outreach activities to educate and enthuse a broad range of audiences about the importance of the Arctic in the climate system.

Website:
The website is the central point for gathering, redistributing, disseminating and enhancing project information and provides information on different aspects of the project, its topics, education and data accessibility. Additional impact will be achieved through, blogs, real-time data feeds from our drifting platforms, a Press Room for journalists, and more.

Training and Education:
Training and education within our programme will mostly be delivered through partner institutions via their post-graduate schemes, such as the course on 'Communicating science to the public'. Because of the nature of this project (UK-German collaboration) we will fund a minimum one month exchange between our early-career scientists so they can experience work at our respective organisations. The purpose of the exchange is to encourage these scientists to interact with institutes beyond their home counties and establish lifelong collaborations both nationally and internationally.