Overview of Working Group Report on Implementation Plans for the CCSP Deliverable: "Re-analyses of historical climate data for key atmospheric features. Implications for attribution of causes of observed change"

1
Ongoing Analysis of the Climate System (OACS)

• Relationship of OACS to
• CCSP Strategic Plan
• CCSP Key Synthesis and Assessment Product
• The fundamental need for updated and ongoing
  comprehensive analyses of the climate system is
  well recognized by the CCSP. This need is not
  new. It has been repeatedly emphasized by the
  scientific community and science advisory panels,
  including those advising NOAA at this meeting,
  e.g.,
• Given the continuing improvement in our
  understanding of climate observations and the
  need for long time series, reprocessing is and
  will always be the hallmark of every climate
  observing system.
• (NOAA Climate and Global Change Advisory Panel,
  2002).

2
Relationship to the CCSP Strategic Plan
Specific CCSP SP goals, questions, objectives,
research foci, and products directly connected or
dependent on ongoing climate analyses are listed
in Ch 2. Integrating Climate and Global Change
Research Ch 4. Climate Variability and Change
(in three of five questions). Ch 10. Modeling
Strategy. Ch 11. Decision Support Resources
Development. Ch 12. Observing and Monitoring the
Climate System. Ch 13 Data Management and
Information. Ongoing climate analyses, and
periodic reanalyses, are vital to the success of
the CCSP. Such analyses directly support
strategies across several major program
elements. They directly link observations with
modeling, and strongly contribute to advancing
understanding and predictions of climate and to
the development of decision support resources.
3
CCSP Key Synthesis and Assessment Product
The fidelity and interpretation of climate
analyses, including uncertainties, is a key issue
for informing policy analysis and
decision-making. Hence, the CCSP principals
identified climate reanalyses - together with
implications for attribution of causes of
observed change - as one of 21 high-priority
synthesis and assessment products to be delivered
within the next 2-4 years. CCSP Product
Reanalysis of historical climate data for key
atmospheric features. Implications for
attribution of causes of observed
change. Agencies NOAA, NASA co- lead, DOE
supporting. Primary end use To inform policy
decisions. Significance Understanding the
magnitude of past climate variations is key to
increasing confidence in the understanding of how
and why climate has changed and how it may change
in the future.
4
Update on Progress and Plans
The CCSP strategic plan provided only general
guidance on the expectations and format of the
synthesis and assessment products. Guidance is
yet to be finalized on the process for developing
and producing the synthesis and assessment
products (in public review through May 3). Based
on initial guidance, an interagency science
working group (SWG) was convened late in 2003 to
begin plans for developing this CCSP product(s).
5
SWG Members
Co-chairs Siegfried Schubert (GSFC/NASA), Glenn
White (EMC/NOAA).

• Jeff Anderson (NCAR)
• Michael Bosilovich (GSFC/NASA)
• Gilbert Compo (CDC/NOAA)
• Tom Delworth (GFDL/NOAA)
• Huug van den Dool (CPC/NOAA)
• Wesley Ebisuzaki (EMC/NOAA)
• Mike Fiorino (LLL/DOE)
• Martin Hoerling (CDC/NOAA)
• Roy Jenne (NCAR)
• Eugnia Kalnay (Univ MD)
• Robert Kistler (EMC/NOAA)

• Arun Kumar (CPC/NOAA)
• John Lanzante (GFDL/NOAA)
• Steven Pawson (GSFC/NASA)
• David Rind (GISS/NASA)
• Suranjana Saha (EMC/NOAA)
• Ben Santer (LLL/DOE)
• Max Suarez (GSFC/NASA)
• Kevin Trenberth (NCAR)
• Jeffrey Whitaker (CDC/NOAA)
• Jack Woolen (EMC/NOAA)

Reviewers John Roads, Masao Kanamitsu (SIO), Jim
Kinter (COLA)
6
SWG progress report
The SWG conducted several meetings/teleconferences
during December-March to identify key issues and
possible products. There has been vigorous and
useful debate in these meetings on directions and
priorities in response to the CCSP language. To
address major unresolved questions of the SWG, a
meeting was held February 27 with Richard Moss,
CCSPO Director. Attendees included Schubert and
White (IWSG co-chairs), Koblinsky,Laver, Lord and
Dole (NOAA), Cahalan and Lee (NASA), Arkin (U.
MD). Moss indicated that the general directions
and questions being considered by the the SWG
were appropriate, and that both reanalysis and
attribution should be included in the
synthesis/assessment product(s). The SWG
completed a first draft prospectus on March 24.
7
Proposed foci for rean/attribution

• Proposed Primary Activities and Deliverables
• A. State-of-science science reviews
• 1. Assessment of first generation
  reanalysis products
• 2. Assessment of current understanding
  of causes of 20th
• century climate variability and
  trends
• B. Develop high quality observational datasets
  for reanalyses.
• C. Initiate next generation reanalyses
• Three proposed activity streams
• 1. Satellite era (1979 to present)
• 2. Period with substantial upper air
  network ( post-1948)
• 3. Period with minimum set of surface
  obs (1895 to present)

8
Proposed SARs

• CCSP Synthesis and Assessment Reports
• Proposed report topics
• 1) State-of-science assessment of strengths and
  weaknesses of first generation reanalyses,
  focusing on their suitability for studies of
  climate variability and trends.
• State-of-science assessment of present knowledge
  of understanding and uncertainties of causes of
  observed climate variations and trends during the
  20th century.
• Possible additional report, or in 1)
• 3) Report on progress since first generation
  reanalysis to improve climate analyses and
  reanalyses, key issues, and necessary further
  steps to address outstanding science and
  policy-relevant questions.

9
Scientific and Technical Challenges

• Data inhomogeneities and model biases.
• How to optimize reanalyses for climate research?
  Use of data, minimization of spurious trends,
  bias, etc.
• Representation of processes and forcing, e.g.,
  precipitation, clouds, interactions with surface.
  
• Horizontal and vertical resolution.
• Improved estimates of uncertainties.
• Extension of reanalyses back in time
  (pre-radiosonde era).

10
Analysis of pre-radiosonde era
Third stream Reanalysis before the radiosonde era

• Can identification and descriptions of
  large-scale climate variations (e.g.,
  teleconnections, storm tracks) prior to the
  radiosonde era be improved through reanalysis
  methods?
• Current analyses consist of subjectively produced
  hand-drawn SLP maps that did not use all
  available observations. Can modern data
  assimilation systems improve on these analyses?
• Before 1948, few upper-air observations are
  available, but many new surface observations have
  been recovered. Can surface pressure observations
  alone provide sufficient data to produce useful
  analyses of the lower troposphere?
• This possibility has been tested, using data
  removal and ensemble
• data assimilation techniques, with analyses using
  only
• surface pressure observations at data densities
  representative
• of earlier times (1895, 1915, 1935).

11
500mb Height Analyses for 0Z 15 Dec 2001
5500 m contour is thickened Black dots show
pressure observation locations
Full CDAS (120,000 obs)
EnSRF 1895 (214 surface pressure obs)
RMS 39.8 m r (z,NH) 0.96
OI 1895 (214 surface pressure obs)
RMS 82.4 m
12
Results indicate that

• Reanalyses of the lower-tropospheric circulation
  prior to 1948 are feasible using just the
  available surface observations.
• Using recent advances in ensemble data
  assimilation methods may improve results, even in
  the upper troposphere.
• Providing additional observations, especially in
  data sparse regions, will produce further
  improvement. Present approaches and data coverage
  should enable lower tropospheric reanalyses that
  are as accurate as current 2-3 day forecasts.

13
Funding Status and Plans for Ongoing Analysis of
the Climate System

• OGP funded first reanalysis. Present NOAA funding
  is through base.
• Budget changes (current plan)
• FY04 0
• FY05 0
• FY06-FY10 Proposed funding increase in NOAA
  plan.
• What are realistic funding requirements to build
• and sustain these efforts?

14
Some key issues

• Leadership. Will NOAA take on this role?
• Funding. Direct implications for time lines,
  scope of activities, deliverables.
• Approval of initial deliverables. What else could
  or should be accomplished before FY08?
• Roles and responsibilities. Coordination within
  NOAA and across agencies and with extramural
  community.
• International coordination. Linkage to EOS/GEO.

15
Summary - Overall Strategy

• A complete climate observing system requires both
  ongoing, near-real time climate analyses and
  periodic reanalyses that use improved data sets
  and data assimilation methods. Both must
  considered as essential components of a long-term
  climate observing strategy.
• CCSP high-priority synthesis and assessment
  products are short-term deliverables (next 1-4
  years). While they may take different forms, they
  are typically envisioned as state-of-science
  reports.
• Without doubt, the CCSP synthesis reports place
  another burden on the science community. They
  are also an opportunity.
• So far, reanalysis efforts have focused
  principally on the atmosphere. A longer-term
  strategy must be developed to analyze and
  eventually bring together the other, disparate
  components of the Earth system (oceans, land,
  cryosphere, hydrology, biosphere) through coupled
  model assimilation. This will enable a more
  comprehensive synthesis and understanding of the
  climate system.