# Presentation: 076262

## Climate Initiatives and Opportunities 

- J. J. Hack (NCCS)

## Climate

- Global climate is driven by energy from the Sun and modulated by atmospheric composition

## Changing Atmospheric Composition:

**Carbon Dioxide (ppm) **

**Methane (ppb) **

**Nitrous Oxide (ppb) **

**Radiative Forcing (Wm****-2****)**

**Radiative Forcing (Wm****-2****)**

**Radiative Forcing (Wm****-2****)**

***Changing Atmospheric Composition:***
***Indicators of the Human Influence***

## Global Mean Surface Temperature Anomalies

*Global Mean Surface Temperature Anomalies*

## Summary for Policymakers (IPCC AR4)

***Global and Continental Temperature Change****** ***

## Summary for Policymakers (IPCC AR4)

***Global and Continental Temperature Change****** ***

## Regional Impacts of Climate Change

- Mote et al 2005

- Observed Change 1950-1997
- 		 Snowpack				Temperature

**(****-**** ****+****)**

**(****- ****+****)**

## Regional Climate Change

***Regional Climate Change***

## Regional Climate Change

**DJF**

**2080-2099 (A1B) - 1980-1999**

**Precipitation (%)**

**JJA**

## Climate change

***Climate change***
***and its manifestation ***
***in terms of weather***
***(climate extremes)***

## Extreme EventsStorms, Floods,Droughts, Cyclones

- More frequent droughts and periods of intense precipitation
- Direct loss of life and injury
- Indirect effects
- Loss of shelter
- Population displacement
- Contamination of water supplies
- Loss of food production
- Increased risk of infectious disease epidemics (diarrhoeal and respiratory)
- Damage to infrastructure for provision of health services

## Atmospheric Motion Spectra

- Nastrom and Gage (1985)

- >106 operation count

## Atmospheric Energy Transport

- Synoptic-scale mechanisms

-  extratropical storms

- http://www.earth.nasa.gov

## Capturing Primary Phenomenological Scales of Motion in Global Models

## High Resolution Climate Simulation

- Column Integrated Water Vapor

## Improving Climate Models

** ****Efforts to reduce systematic errors crucial – biases affect both**
**   ****a model’s climate sensitivity and also utility as a predictive tool**
** ****Approaches: (1) improve existing physical parameterizations**
**                         ****(2) more accurate incorporation of phenomena **

** ****A working hypothesis is that the internal dynamics of the system**
**   ****are more accurately represented at higher resolution**

***Resolving tropical instability waves***

***Improving Climate Models***

**Notes:**
REQUIREMENTS.		
Computer resources.
Data, interfaces and software standards and encapsulations.

## Process Models and Parameterization

## Improving Climate Models

***Upscaling Research***

** ****Basic requirement: the research community needs to gain **
**   ****considerable experience running models in climate mode with   **
**   ****mesoscale processes resolved, together with theoretical and **
**   ****diagnostic efforts, to:**
** ****improve understanding of multiscale interactions in**
**    ****the coupled system**
** ****identify those of greatest importance and those that **
**    ****require more data to understand**
** ****document their upscaling effects on climate**
** ****identify those processes that can be parameterized, and**
**    ****those that cannot**

## CCSM Example: Evolution toward an ESM

*Ocean*

*Coupler*

*Sea Ice*

*Land*

***CCSM Example: Evolution toward an ESM***

**Coupled climate-chemistry model in the immediate future**
**Terrestrial and oceanic biogeochemical models **
**Ocean ecosystem and terrestrial C/N models **
**Ability to simulate interactions of aerosols with water and biogeochemical cycles**
**Explore and understand importance of upper atmospheric process**
**Land use and land cover change**

## Science Opportunities

- Decadal prediction on regional scales
- Accuracy in global models
- Climate extremes (heat waves, drought, floods, synoptic events, etc.)
- Climate variability (low frequency variability)
- Water cycle, particularly in the tropics
- Potential impacts on biofuels
- Interactions of the water cycle on mitigation and adaptation strategy
- Amplifier on carbon cycle response to global warming
- Human induced impacts on carbon cycle
- Half impacts are taken up by the system (will that change?)
- How will climate change affect the carbon cycle?
- Sea level rise
- Melting of the Greenland and Antarctic ice sheets
- Abrupt climate change

## Models

- Carbon cycle
- Forcing terms that represent multiscale nature of problem
- e.g., water cycle
- Need for evaluation infrastructure (accelerate prototyping process)
- Test cases
- Data for evaluation
- Staged increases in complexity
- Modularized functionality
- Validation and Verification tests

## Observations

- Carbon cycle measurements activities
- Unique opportunity to integrate measurements into models
- Enhanced process modeling for incorporation in component models
- Assimilation systems for chemical and biogeochemical observations
- Use of in situ and satellite observations
- Continued investments in targeted process studies like ARM
- Decade of experience in fielding complex observational systems
- Resolve continuing uncertainties about clouds, aerosols, and radiation

## Computational Algorithms

- Scalable isotropic dynamical cores
- dynamic load balancing capabilities
- Alternative vertical discretizations
- Implicit or large time step discretizations
- Robust grid remapping algorithms
- Assimilation methodologies
- Ocean, carbon cycle, ...
- adjoints, ensemble Kalman filters, ...
- Need to address multiscale science
- Variable resolution refinements
- Uniform high-resolution
- Error estimation techniques

## Production Quality Software

- High-performance parallel I/O standard
- Future programming models
- MPI/OpenMP replacements
- Methodologies and tools required to exploit highly parallel architectures
- performance analysis tools
- libraries
- Tools for refactoring application codes
- Language improvements
- Componentization
- verification; unit testing, ...
- Scalable and distributed analysis software
- Math and application frameworks
- Benefits to partnerships in development of software environment
*DOE needs to exercise more control of the broader activity*
- Substantial investment in software for current and future machines a priority

## Summary

- Global Climate Modeling
- complex and evolving scientific problem
- Better parameterizations of physical processes are pacing progress
*these are not necessarily well posed problems*
- observational limitations are pacing process understanding
*this has ALWAYS been an important rate-limiting component*
- computational limitations pacing exploration of model formulations
- explorations of resolution parameter space, process modeling, system sensitivities, model validation (e.g., reproduce paleo record)
- Many scientific and technical opportunities
- ORNL is assembling infrastructure with which to partner
- both technical and intellectual partnerships across wide range of science interests

## The End