Climate Science Programme
The context for our climate programme is the very high level of uncertainty that characterises current climate predictions. This uncertainty reflects both weaknesses in climate models and weaknesses in understanding. NCAS has particular strengths in analysis and understanding of the processes that govern climate variability and change. As illustrated, there is a very close link between advances in process understanding and advances in climate models and prediction systems. In this context, our partnership with the Met Office Hadley Centre is a key element of our strategy. We will work with the Met Office, and with the wider NERC community, “To ensure, in areas of common interest, that the UK maintains and strengthens its leading international position in climate science, and hence in climate forecasting and provision of advice for climate policy”.1 We will also build partnerships with other organisations, where we have complementary aims and capabilities.
Frontiers of climate model development and evaluation
Through projects such as HiGEM, UJCC, UKCA, QESM and CASCADE2, NCAS has played a pioneering role in advancing the frontiers of climate modelling in the UK. In partnership with the Met Office we will improve these capabilities further through increases in horizontal and vertical (including stratospheric) resolution, improved parametrisations, and incorporation of new processes (e.g. new interactions between climate and composition, and earth system feedbacks). We will focus especially on process-based evaluation against observations of the benefits that arise from specific model developments, developing our partnership with the National Centre for Earth Observation Where appropriate (e.g. CASCADE) we will use regional models to understand processes and guide the development of global models.
Processes governing global and regional changes in climate and composition
Many processes influence the climate response to forcing by anthropogenic (e.g. greenhouse gases, ozone, aerosols) and natural (e.g. volcanoes, solar variability) factors, e.g. changes in: atmospheric circulation; clouds and the hydrological cycle; and interactions between the atmosphere, ocean and land surface (including Earth-system feedbacks). We will undertake research to determine the responses of global and regional climates to different forcing factors.
NCAS has made a major contribution to the ECMWF ERA-interim reanalysis project, with particular focus on the development and dissemination of diagnostics. We will seek to build on this activity, e.g. developing new diagnostics and analysis tools, and will carry out research to identify the causes of (attribute) - where possible at a process level - specific observed changes in climate and climate events (e.g. July 2007 floods).
NCAS has made major contributions to the international assessments by IPCC and WMO/UNEP of chemistry/climate interactions. We will continue to play a leading role in this area, exploiting our chemistry-aerosol-climate model, UKCA, by contributing scientific understanding to assessments of the state of the stratospheric ozone layer, the oxidizing capacity of the troposphere and changes in air quality at global and regional scales.
Natural climate variability and high impact events
Confidence in climate predictions must be built on understanding of the processes that control the underlying time-mean climate in different regions, and its natural internal variability. We will undertake research to understand and quantify the processes underlying variability in the tropics (e.g. El Nino Southern Oscillation, Madden Julian Oscillation, Monsoon active/break cycles), higher latitudes (e.g. storm-track, North Atlantic Oscillation, Atlantic Multi-decadal Oscillation), and in the stratosphere (e.g. sudden warmings, Quasi-Biennial Oscillation). We will collaborate with the NCAS Weather programme to determine the consequences of natural climate variability, and anthropogenic climate change, for the occurrence of high impact weather and climate events, including research to explore the potential of regional climate modelling for impact assessment, and research to develop statistical modelling approaches for high impact events. We will evaluate, and work to improve, the representation of natural climate variability in climate models.
Climate prediction and predictability
The development of capabilities for predictions of climate that are initialised with observations is a major opportunity to advance climate science, offering in particular a new approach for testing models against observations at a process level. In collaboration with others (notably the Met Office, NCEO, ECMWF) we will work to develop and exploit capabilities for initialised monthly-to-decadal climate predictions. These capabilities include the new Met Office climate prediction system that – building on research by NCAS and others – includes, for the first time, a proper representation of the stratosphere. In partnership with the Met Office we will make major contributions to the CMIP5 project that is being conducted to inform the IPCC fifth assessment report, contributing initialised hindcasts with the high resolution HiGEM model, and simulations to examine the impact of stratospheric resolution on past and future climate change. The execution, diagnosis and interpretation of these and other CMIP5 simulations will be a major activity. We will also carry out research on: the use of observations with models to constrain climate predictions; quantifying the limits of climate predictability; the design of ensembles for climate predictions.
Climate Change Impacts
Assessments of climate change impacts must be informed by the best possible knowledge of the underlying processes. We will build partnerships with research, government and commercial organisations to assess the consequences of climate variability and change for high impact weather events (e.g. tropical cyclones, wind storms), wider climate impacts (e.g. on water resources and crop productivity), and adaptation options.
1 This statement is the overarching goal of the NERC – Met Office Joint Climate Research Programme, launched in March 2009.
2 HiGEM: UK High resolution climate modelling programme; UJCC: UK-Japan Climate Collaboration; UKCA: UK Chemistry and Aerosol programme; QESM: QUEST Earth System Modelling project; CASCADE: studies of convective organisation using large domain cloud system resolving model simulations