ACSIS

Enhancing the UK’s capability to detect, attribute and predict changes in the North Atlantic Climate System

ACSIS will improve the UK’s capability to detect, explain and predict changes in the North Atlantic Climate System. Led by NCAS, in partnership with CPOM, NOC, BAS, PML and NCEO, ACSIS will exploit expertise in observing and simulating atmospheric composition, the ocean, the cryosphere, and the fully coupled climate system.  The observational component will bring together records from ground- and space-based platforms with a focus on the sustained observations that are necessary to measure changes on multi-year timescales.  The modelling component will involve core simulations with cutting-edge atmosphere, ocean, sea ice, chemistry and aerosol models, as well as bespoke experiments. ACSIS will also work closely with the UKESM to produce new long-term observational datasets, syntheses, modelling capabilities and simulations.

CPOM role: provision of Earth Observation (EO) data and model simulations

CPOM’s input, led by Danny Feltham, will include sea ice volume estimates based on satellite observations of freeboard height.  This will then be converted to thickness and volume to give a continuous ongoing record of Arctic sea ice and Greenland volume change (Alan Muir/Andy Ridout).

Variable
Satellite Instrument Time Span Resolution
Temporal Horizontal Vertical
Land ice and sea ice elevation
CryoSat-2 2010-present 369-day, 30-day sub cycle 0.3 (along track) x 1 (across track) km < 4 cm
ERS1&2 1992-2011 35-day 10 km < 10 cm
EnviSat 2002-2012 35-day 10 km < 10 cm

Model simulations (David Schroeder) will be carried out using CICE (the Los Alamos Sea Ice model).  This will include delivery of ¼ degree ice-ocean simulations using latest CPOM CICE model.  In addition, CPOM will provide a diagnosis of trends and variability in Arctic sea ice with analysis of energy and mass budgets to determine proximate cause of changes; and attribution of changes in Arctic sea ice in both the observations and simulations.