Transcript Report of DPWG

US CLIVAR Decadal Predictability
Working Group Report
Co-Chairs:
Lisa Goddard -- IRI, The Earth Institute of Columbia University
Amy Solomon -- CIRES/University of Colorado & NOAA/ESRL
Arun Kumar -- NOAA/Climate Prediction Center
US CLIVAR Summit 2009
US CLIVAR Decadal Predictability
Working Group
Formally approved January 2009
Objective 1: To define a framework to distinguish natural
variability from anthropogenically forced variability on
decadal time scales for the purpose of assessing predictability
of decadal-scale climate variations.
Objective 2: Work towards better understanding of decadal
variability and predictability through metrics that can be
used as a strategy to assess and validate decadal climate
prediction simulations.
US CLIVAR Summit 2009
Membership
US Membership:
Jim Carton
(University of Maryland)
Tom Delworth
(NOAA/GFDL)
Clara Deser
(NCAR)
Ichiro Fukumori (JPL/NASA)
Lisa Goddard
(IRI/Columbia University)
Ben Kirtman
(University of Miami)
Arun Kumar
(NOAA/CPC)
Yochanan Kushnir (Columbia University)
Matt Newman
(CIRES/NOAA)
Amy Solomon
(CIRES/NOAA)
Dan Vimont
(University of Wisconsin)
Ex-officio Members:
Arthur Greene
(IRI/Columbia University)
Gabi Hegerl
(University of Edinburgh)
Jerry Meehl - representing WGCM (NCAR)
Doug Smith
(UK Met Office)
Tim Stockdale - representing WGSIP (ECMWF)
US CLIVAR Summit 2009
Scientific Focus of Telecons
1: How best to separate natural decadal variability from
anthropogenically forced decadal variations?
(Kushnir 2009)
US CLIVAR Summit 2009
Scientific Focus of Telecons
2: How do we address the issue of potential projection and
interaction between the natural and forced variability?
The mid-1970s climate
shift in the Pacific was
likely a combination of
internally generated
decadal variability and a
forced response
Forced
Inherent
response decadal
(~25%)
(~50%)
Inherent and
forced (~25%
each)
US CLIVAR Summit 2009
(Meehl, Hu, and Santer, 2009:
The mid-1970s climate
shift in the Pacific and the
relative roles of forced
versus inherent decadal
variability, J. Climate, 22,
780--792.)
Timeline

June 2009: 1st Group Meeting and Session on “Advances in
Decadal Climate Prediction” at the CCSM Workshop in
Breckenridge, CO.
•
Fall 2009: Submit white paper on “What additional skill we can
expect from the initialized decadal predictions, and why?”
•
Winter 2009/10: Group Meeting? (RSMAS Wrkshp)
•
Spring 2010(?): Announcement of Opportunity by funding
agencies for small grants to investigate decadal predictability in
the AR5 initialized decadal climate projections
•
Fall 2010: Group Meeting? (WGOMD Mtg)
•
Spring 2011: Meeting on “Defining Metrics Relevant to Dynamical
Decadal Predictions”
•
Summer 2011: Write workshop report and WG wrap-up focused
on decadal prediction metrics
US CLIVAR Summit 2009
Coordination with other Working Groups
US CLIVAR AMOC Science Team would like…


Input on separation of forced and natural components
for AMOC
Metrics for evaluating the AMOC in model simulations
CLIVAR Working Group on Ocean Model
Development
 DPWG invited to participate in next WG meeting in
October 2010, along with AMOC Team
NCAR Climate Change & Climate Variability WGs
 Running additional experiments at request of DPWG
US CLIVAR Summit 2009
Coordination with other Working Groups
(continued)
NCAR Climate Change and Climate Variability
Working Groups
Twin perfect model
experiments that can be
used as a testbed for the
DPWG metrics study
* CCSM3
* 40 member ensembles
* 60-year integrations
Twin #1 : A1B Scenario (runs done)
Twin #2 : Year 2000 Stabilization
US CLIVAR Summit 2009
Time series of CO2
concentrations (ppm)
for scenarios B1, A1B,
and A2, twentiethcentury stabilization
from 2000 to 2100,
twenty-first century
stabilization from 2100
to 2300 for B1 and
A1B; (b) time series of
globally averaged
surface air
temperature anomalies
(°C), 2000–2300, for
the various
experiments (from
Meehl et al. 2006, JC).
Involvement in Workshops
The Eighth Workshop on Decadal Climate Variability
Decadal Climate Predictability and Prediction: Where Are We?
12-15 October, 2009; St. Michaels, Maryland
Organizing committee: Lisa Goddard (IRI), Arun Kumar (NOAA-CPC), Mojib Latif (IFMGEOMAR), Tong Lee (NASA-JPL), Jerry Meehl (NCAR), Vikram Mehta (CRCES), Tony Rosati
(GFDL), Jeff Knight (Hadley Centre), and Detlef Stammer (Univ. of Hamburg)
Predicting the climate of the coming decades
January 11-15, 2010; RSMAS, Miami, FL
Workshop goal:
The goal of this workshop is to bring together people from different communities who have
shared interests in predicting the climate of the coming decades.
Key elements:
Socioeconomic considerations, Mechanisms of decadal variability, Decadal predictions & forced
climate change, Applications, Long-term risk management, Marine ecosystems, Water
resources, Public lands, Coastal Management, Airports, Metropolitan planning organizations
US CLIVAR Summit 2009
White Paper in Preparation
Focus:
Summarize and critique methodologies to distinguish natural decadal
variations from anthropogenically-forced variations in order to assess
the potential contribution of initialization for decadal predictions.
Questions addressed:
 Can we estimate the relative amplitude, and spatial structure,
of natural and forced decadal variability? What approaches can be
used to separate natural decadal variability from
anthropogenically forced decadal variations? How does the
analysis depend on the chosen method?
How does forced variability interact with the natural
variability?
What robust estimates of observed trends and/or decadal
variations exist to validate the models?
…To be submitted to BAMS September 2009
US CLIVAR Summit 2009
Assembling Databases for
Metrics Study
1) CMIP3 Database
2) Twin perfect model experiments with CCSM 40member ensembles
3) Smith et al data (initialized HadCM3 expt.s)
4) Ben Kirtman’s CCSM simulations
5) Anticipating CMIP5 Decadal Prediction Expt.s
6) What else?
US CLIVAR Summit 2009
Planning for Broad Community
Participation in Analysis of Decadal
Prediction Experiments

CMEP (2004): Coupled Model Evaluation Project



DRICOMP (2007): DRought In COupled Models
Project



19 Funded Proposals (+ 2 lab funded)
18 Papers published (at least)
16 Funded Proposals
Papers to Journal of Climate special issue on drought
(together with results from US CLIVAR Drought WG)
DECPREP (2010): DECadal PREdictability Project
US CLIVAR Summit 2009