MISSION STATEMENT: Our mission is to foster improved practices in the provision, validation and uses of climate information and forecasts through coordinated participation within the U.S. and international climate science and applications communities.

PPAI GOALS

1. Further fundamental understanding of climate predictability at seasonal to centennialtime scales
• Develop and promote standard metrics and practices for evaluating predictability and prediction
• Encourage coordinated U.S. participation in emerging international multi-model predictiona nd attribution activities
• Quantify prediction uncertainty and its sources
• Assess predictability of key climate forcings
2. Improve provision of climate forecast information, particularly with respect to drought and other extreme events
• Assess baseline predictability of drought on weeks to decades.
• Coordinate and “advertise” scientific support for multi-agency research efforts that address local and remote sea-air-land mechanisms of drought and its predictability, at interannual to decadal timescales(joint with GEWEX)
• Assess possible future changes in drought
• Identify/collect/document monsoon indices to observe and predict (help from POSP)
• Assess baseline simulation capability of complete annual cycle of global monsoon and its variability, including diurnal component (help from PSMIP)
• Assess baseline predictability of identified monsoon indices
• Quantify relative roles of ocean/atmosphere and land/atmosphere processes (with POSP & PSMIP)
• Assess potential future changes of global monsoons
3. Foster research and development of prediction systems for climate impacts on ecosystems
• Improve understanding of oceanic and atmospheric patterns, and consequent forcing mechanisms, that organize ecosystems and determine the spatial and temporal distribution of water resources. (with PSMIP)
• Quantify the predictability of key oceanic and atmospheric processes that influence ecosystems and water resources.
• Develop tools for transforming climate forecasts into ecosystem and water resource forecasts at lead times from sub-seasonal to centennial and at appropriate spatial scales
• Develop ability to quantify relative contributions of anthropogenic climate change and natural climate variability to observed long-term changes in ecosystems and water resources
4. Enable use of CLIVAR science for improved decision support
   • Develop integrated linkages to interdisciplinary programs: NOAA RISA and OGP, IRI, IPCC, CCSP, NASA efforts, NSF NEON / CUAHSI / CLEANR / ORION, Ocean Observing Systems, public entities such as WGA / NGA.
   • Promote/support projects that link climate observations, forecasts, and scenarios with resource assessments and forecasts
   • Promote sustained interactions with other disciplines and research communities to ensure delivery of “usable science”
   • Emphasize spatial and temporal scales of information needed for applications. Contribute support for the development, use, interpretation, and evaluation of tools (e.g. downscaling) employed by applications.

Terms of Reference

• Review, prioritize, and coordinate US plans to characterize predictability, and demonstrate improved prediction capabilities, on sub-seasonal, seasonal, S-I, decadal, and century and longer time scales as necessary to achieve the goals of CLIVAR.
• Interface with agency and CCSP activities and groups (e.g. NOAA-NMFS, IRI, and RISAs; NASA-RESACs, RACs, and ESIPs) to identify user requirements for useful climate information, improve the communication of these requirements, and encourage development of appropriate tools and approaches for improved decision support capabilities.
• Coordinate US efforts to insure advances in prediction research have appropriate connections and pathways into operational forecast system development.
• Develop and encourage mechanisms (e.g. community workshops, commissioned studies, Working Groups) to further the development and implementation of a research strategy, including filling gaps. Advise on the adequacy and effectiveness of Working Group plans and their implementation.
• Advise US CLIVAR on research priorities, identify research gaps, and develop suitable milestones to promote funding opportunities. Help foster and coordinate joint agency participation and support of relevant activities.
• Publicize accomplishments and demonstrated progress in research leading to improved prediction capabilities and applications of prediction information.
• Coordinate with other national and international activities to develop integrated, efficient, and effective overall international plans and activities.
• Liaise with other US CLIVAR panels and Working Groups to insure prediction is considered in their efforts.

The entire PPAI Strategic Plan can be found here.

References

Meetings

AGU Special Session - December 2006

PPAI Panel Meeting - December 14, 2006

• Minutes (pdf)
• DecVar discussion (pdf)

A36:
Increasing Credibility of Climate Predictions
Conveners:
Alex Hall, UCLA, Dept. of Atmospheric and Oceanic Sciences
Lisa Goddard, International Research Institute for Climate and Society, Columbia University
The purpose of this session is to examine the credibility of state-of-the-art climate predictions from seasonal to centennial time scales, with an eye toward improving them. On seasonal to interannual time scales, prediction skill can be evaluated statistically by comparing ongoing model predictions to the climate record as it evolves. However, to improve predictions on these time scales, it is necessary to identify and understand the physical mechanisms responsible for predictability and ensure they are properly included in models. On the longer time scales of climate change, it is challenging to evaluate prediction credibility, let alone improve it. The variation of the past century is the only example of forced climate change that has been adequately sampled on a global scale, so rigorous evaluation of model performance is limited to this single realization. Moreover, while current models give widely diverging predictions when identical future forcing scenarios are imposed on them, are all able to simulate a “hindcast” of the past century within observational constraints when realistic past forcing is imposed. Unlike the seasonal to interannual case, the observed climate record is of limited utility in determining which future projections are most realistic. On these time scales, the community is therefore forced to rely almost exclusively on the plausibility of the physical mechanisms underlying simulated climate change. Because of the importance of physical mechanisms in establishing prediction credibility and improving it on all time scales, we solicit papers that identify these mechanisms or evaluate their plausibility. We also solicit work on statistical methods demonstrating prediction reliability on seasonal to interannual time scales, and novel techniques for assessing model credibility on longer time scales.

U.S. CLIVAR Summit - 2007 July 23-25

• PPAI Concluding Report (pdf)

U.S. CLIVAR Summit - 2006 July 26-28

Presentations from the Summit are provided:

• PPAI report (ppt)
• PPAI concluding remarks (ppt)

U.S. CLIVAR Summit - 2005 August 15-18

The PPAI panel met in Keystone, Colorado to discuss ongoing and future panel activities. Presentations made to the panel are provided below.

• Climate Test Bed
• Drought Summary
• Ecosystem Summary
• NAME report
• MESA report
• Subseasonal prediction proposal
• SEARCH status