Major changes are occurring across the North Atlantic climate system: in ocean and atmosphere temperatures and circulation, in sea ice thickness and extent, and in key atmospheric constituents such as ozone, methane and particles known as aerosols. Many observed changes are unprecedented in instrumental records. Changes in the North Atlantic directly affect the UK’s climate, weather and air quality, with major economic impacts on agriculture, fisheries, water, energy, transport and health.
The North Atlantic also has global importance, since changes here drive changes in climate, hazardous weather and air quality further afield, such as in North America, Africa and Asia. ACSIS is a 5 year strategic research programme that brings together and exploits a wide range of capabilities and expertise in the UK environmental science community. It’s goal is to enhance the UK’s capability to detect, attribute (i.e. explain the causes of) and predict changes in the North Atlantic Climate System. ACSIS will deliver new understanding of the NA climate system by integrating new and old observations of atmospheric physics and chemistry, of the ocean state and of Arctic Ice. The observations will be complemented by detailed data analysis and numerical simulations. Observations will come from existing networks, from NERC’s own observational sites in the North Atlantic, and from space. Seasonal surveys using the NCAS FAAM aeroplane will further enhance our observational strategy. A key dimension of the observational opportunity is that data records of sufficient length, for multiple variables, are becoming available for the first time. The modelling component will involve core numerical simulations with cutting-edge atmosphere, ocean, sea ice, chemistry and aerosol models using the latest parameterizations and unprecedented spatial detail, as well as bespoke experiments to investigate specific time periods or to explore and explain particular observations. ACSIS will provide advances in understanding and predicting changes in the NA climate system that can be exploited to assess the impact of these changes on the UK and other countries – for example in terms of the consequences for hazardous weather risk, the environment and businesses. ACSIS outputs will also inform policy on climate change adaptation and air quality.