# Presentation: 228032

## UNDERSTANDING AND PREDICTING CLIMATE VARIABILITY IN THE CONTEXT OF CLIMATE CHANGE

**UNDERSTANDING AND PREDICTING CLIMATE VARIABILITY IN THE CONTEXT OF CLIMATE CHANGE**
**Julia Slingo**
**Director, Centre for Global Atmospheric Modelling, University of Reading**

**‘****Grand Challenge’ modelling in the UK Natural Environment Research Council (NERC):**

## Centre for Global Atmospheric Modelling 

-  To understand and simulate the highly non-linear dynamics and feedbacks of the global climate system
-  To exploit the revolution in seasonal to interannual prediction as a test bed of climate models and as a vehicle for fostering integrated applications
-  To capitalize on and develop NERC expertise in earth system science
-  To harness the expected increases in computer power and the opportunities provided by e-science to perform higher resolution, more comprehensive integrations of the earth system.
*CGAM works closely with the Hadley Centre and uses its state-of-the-art coupled model as its prime research tool. Integration of UK climate research activities is vital for future progress. *

## NERC: Natural Environment Research Council 

- UK lead responsibility for developing, funding and delivering environmental science
- To prioritise and deliver world-class environmental sciences to understand the Earth System.
- Supports research, training and environmental observations across all components of the earth system
- Uses a ‘whole system’ approach to earth system science to find sustainable solutions to environmental problems.

## NERC’s New Strategy: Science for a Sustainable Future

- Earth’s Life-Support Systems: Water, biogeochemical cycles and biodiversity
- Climate Change: Predicting and mitigating the impacts
- Sustainable Economies: Identifying and providing sustainable solutions to the challenges associated with energy, land use and hazard mitigation

## NERC supports scientists within Universities and at its major core research centres:

- British Antarctic Survey (BAS)
- British Geological Survey (BGS)
- Centre for Ecology and Hydrology (CEH)
- Proudman Oceanographic Laboratory (POL)
- Southampton Oceanography Centre (SOC)
- Centre for Terrestrial Carbon Dynamics (CTCD)

- NERC Centres for Atmospheric Science (NCAS)
- Environmental Systems Science Centre (ESSC)
- Data Assimilation Research Centre (DARC)
- Tyndall Centre for Climate Change Research
- National Institute for Environmental e-Science (NIEeS)
- Centre for Polar Observations and Modelling (CPOM)

## Centres and Facilities

- Centre for Global Atmospheric Modelling (CGAM): Climate processes, variability and change
- Atmospheric Chemistry Modelling Support Unit (ACMSU): Chemistry-Climate modelling and interactions
- Universities’ Weather and Environment Research Network (UWERN): High impact weather
- Distributed Institute for Atmospheric Composition (DIAC): Laboratory and field studies of processes in the chemical and physical environment.
- British Atmospheric Data Centre (BADC)
- University Facilities for Atmospheric Measurements (UFAM)
- Facility for Airborne Atmospheric Measurements (FAAM)

## Seasonal forecasts provide an excellent test-bed for coupled models, analogous to the role played by NWP in the development of AGCMs. They provide the scientific underpinning for predictions of anthropogenic climate change. 

- Seasonal forecasts provide an excellent test-bed for coupled models, analogous to the role played by NWP in the development of AGCMs. They provide the **scientific underpinning for predictions of anthropogenic climate change**.

## COUPLER

- A new approach for modelling and understanding the coupled system

- The core of the model is the coupler which exchanges information between different components of the earth system.

**BIO- GEO-**
**CHEMISTRY**

**COUPLER**

**ATMOSPHERIC**
**CHEMISTRY**

**IMPACTS MODELS**
**Crops, water resources**

- DATA
- ASSIMILATION
- SYSTEMS

- REGIONAL
- CLIMATE
- MODEL

## An Infrastructure Project for 
Climate Research in Europe

- Climate Research in Europe

-  Involves current state-of-the-art atmosphere, ocean, sea-ice, atmospheric chemistry, land-surface and ocean-biogeochemistry models
-  22 partners: leading climate researchers and computer vendors
-  Ultimate objective:  Distributed European network for Earth System Modelling
-  See _***http://prism.enes.org***_

- PRISM will:
** ****Coordinate European Climate Modelling efforts**:
-  Create a European service and management infrastructure for European wide, multi-institutional climate and Earth System simulations
** ****Develop a European Climate Modelling System:**
-  Portable, efficient and user-friendly + based on state-of-the-art models
- + diagnostics and visualisation

## Application of modular approach:

- Understanding coupled GCMs

**             ****SINTEX         HadOPA        HadCM3   HadCEM   GloSea  ...**

**HadAM3**

**HadOM3   HadOM3   HadGOM**

**OPA**

**ECHAM**
- T30/T42/T106

**LMDz**

**Common ocean**

**Common atmosphere**

**Intercomparison**		**identify origin of errors**

**Different **
**resolutions**

## What controls El Nino in Coupled Climate Models?

*Exchanging ocean models suggests that:- *
***atmosphere**** controls the ****periodicity***
-  ***ocean**** controls the ****strength**** of El Nino*

*BUT the use of a ****high resolution atmosphere**** (1**0**) dramatically improves the temporal behaviour of El Nino and for the first time provides a more realistic simulation of the lower frequencies.*

## UK-HIGEM 

_***‘***__***Grand Challenge’ High Resolution Modelling***_
_***of the Global Environment***_
*To develop a high-resolution version (initially ~ 1**0 **atmosphere, 0.33**0** ocean) of the Hadley Centre Global Environment Model (HadGEM) and perform a multi-century control integration.** *
*To evaluate the model by stringently testing it against observations and more sophisticated, very high-resolution models of the component parts. *
*To improve our understanding and predictive capabilities in global environmental variability and change, with particular reference to extreme events, interactions between different components of the climate system, and the potential for climate ‘surprises’.*
*To provide the modelling framework in which new developments in numerical methods and key processes in the atmosphere, ocean, cryosphere and land can be efficiently incorporated, leading to the creation of the next generation global environment model** *
*To provide the background models required for the synthesis and interpretation of the wealth of in situ and satellite observations of the global environment, *
*To deliver more robust estimates of the regional impacts of climate change required to guide government policy.** *

## Key Components of ‘Grand Challenge’ Climate System Modelling

- Modelling hierarchy covering range of space/time scales – process studies, non-linear scale interactions, exploring parameter space – but there must be traceability
- Advanced computational methods for resolving key processes, exploiting high resolution EO data – nested grids, AMR, super-parametrizations
- Maintaining model diversity and developing model complexity – modular framework
- Linking with operational activities - NWP, seasonal to interannual prediction
- Confronting models with observations – developing innovative diagnostics
- Integrated assessment – allowing feedback from climate impacts

## Evolving grid approach

- _Evolving grid approach_
- Example of application of adaptive mesh refinement
- (AMR) to tropopause fold event.
- AMR places the
- resolution where the
- situation demands it,
- in this case around PV
- filaments.

*Courtesy Dr. N. Nikiforakis, DAMTP*

## Improved ocean dynamics and mixing with higher resolution

- Image from 1/80 version of  OCCAM Ocean GCM showing salinity jets at a depth of 100m in the South Pacific where the South equatorial Current is blocked by a series of island groups.

- See: http://www.soc.soton.ac.uk/JRD/OCCAM/