Climate Analysis and Reanalysis Program Development Phil Arkin, ESSIC, University of Maryland

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• Climate Analysis and Reanalysis Program
  Development  Phil Arkin, ESSIC, University of
  Maryland
• Programmatic Background
• Atmospheric Activities
• Ocean Activities
• Conclusions and Issues

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We need more comprehensive climate observations
and we must make more efficient use of those that
are and will be available.
THE NEED FOR A SYSTEMS APPROACH TO
CLIMATE OBSERVATIONS BY KEVIN E. TRENBERTH,
THOMAS R. KARL, AND THOMAS W. SPENCE Because
climate is changing, we need to determine how and
why. How do we best track and provide useful
information of sufficient quality on
climate? Bulletin of the American
Meteorological Society November 2002, 83,
1593-1602
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Observing system means a comprehensive approach,
including

• Climate observations from both space-based and in
  situ platforms taken in ways that address climate
  needs and adhere to the ten principles outlined
  by the NRC (1999).
• A global telecommunications network and satellite
  data telemetry capacity to enable data and
  products to be disseminated.
• A climate observations analysis capability that
  produces global and regional analyses of products
  for the atmosphere, oceans, land surface and
  hydrology, and the cryosphere, based on four
  dimensional data assimilation capabilities that
  process the multivariate data in a physically
  consistent framework to enable production of
  the analyses for the atmosphere and oceans, land
  surface and so on.
• Global climate models that encompass all parts of
  the climate system and which are utilized in data
  assimilation and in making ensemble predictions.

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GEOSS--- Creating a System of Systems
Global Observing Systems GCOS GOOS GTOS WHYCOS Wor
ld Weather Watch IGBP IOOS CEOS IGOS
National/Multinational Observing
Systems Satellites Surface Observations Radar Airc
raft Ocean Observations Paleo-data
Private Sector Observing Systems Satellites Mesone
ts Lightning Commercial Aircraft
Climate Variability and Change
Disasters
Agriculture
Ocean Resources
Water Resources
Health
Energy
Ecosystem
Societal Benefits
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GEOSS--- Creating a System of Systems
Global Observing Systems GCOS GOOS GTOS WHYCOS Wor
ld Weather Watch IGBP IOOS CEOS IGOS
National/Multinational Observing
Systems Satellites Surface Observations Radar Airc
raft Ocean Observations Paleo-data
Private Sector Observing Systems Satellites Mesone
ts Lightning Commercial Aircraft
Integration / Synthesis / Analysis (of the
physical climate system)
Climate Variability and Change
Disasters
Agriculture
Ocean Resources
Water Resources
Health
Energy
Ecosystem
Societal Benefits
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Reprocessing and Reanalysis are essential
Given the continuing improvement in climate
observations and the need for long time series,
reprocessing is an essential element of every
climate observing system.
Workshop on Ongoing Analysis of the Climate
System18-20 August 2003, Boulder, Colorado

• Workshop report distributed
• See workshop web site (http//www.joss.ucar.edu/jo
  ss_psg/meetings/climatesystem/) for pdf version
  of report and background information from the
  workshop.

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The Workshop concluded that the U.S. must
establish a National Program for Ongoing Analysis
of the Climate System to provide a retrospective
and ongoing physically consistent synthesis of
earth observations in order to

• Guide the design and operation of observing
  systems
• Produce and sustain the growing climate record
• Reconcile disparate climate observations and
  characterize analysis uncertainty
• Establish initial conditions for climate
  prediction
• Validate prediction and projection models on all
  time scales
• Provide long time series of global and regional
  climatic analyses for all types of prediction and
  projection verification

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Elements of a Comprehensive Ongoing Analysis of
the Atmosphere

• Enhancing and managing the observational database
• Archeology, new sensors, continuity and feedback
• Ongoing analysis
• Continually update most recent reanalyses (CDAS)
• Use OSEs and OSSEs to document impact of
  continuing observing system changes
• Provide feedback to observing system
  developers/operators
• Periodic reanalyses
• Post 1979 reanalysis with goal of continuous
  climate record
• Post 1950 reanalysis with same goal
• Post 1850 surface NH oriented
• Continental-scale regional reanalysis at very
  high spatial resolution
• Stewardship and dissemination
• Ensure that the products are useable
• Applied research
• Develop improved methods and products
• Intended to solve problems identified within
  program

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Current/Planned U.S. Atmospheric Activities

• Climate Data Assimilation System (CDAS)
  operational extension of NCEP/NCAR reanalysis run
  by CPC
• Regional CDAS operational extension of Regional
  Reanalysis, also run by CPC
• MERRA (Modern Era Reanalysis for Research and
  Applications) NASA/GSFC research project
  focused on satellite era hydrological cycle
• Surface-based reanalysis of Northern Hemisphere
  NOAA/CDC research project

• Extension of MERRA to include climate transition
  during 1970s
• Community Reanalysis System
• Consolidated reanalysis database suitable for
  distributed experiments
• Facility for a variety of experiments (OSE/OSSEs,
  system test, etc.) could be either a portable
  code or a testbed
• CCSP reanalysis support

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CLIVAR Ocean Reanalysis WorkshopNov 8-10, 2004 -
Boulder, COAn activity of the CLIVAR Global
Synthesis and Observations Panel (GSOP)
Workshop Objectives Establish the
requirements for ocean reanalysis. Review the
usage of ongoing and planned ocean reanalysis
efforts. Stimulate new applications of
existing ocean reanalyses. Review the synergy
between ocean and atmospheric reanalysis
activities. Review long-term observing system
strategies and designs. Identify model
improvements required for ocean and coupled
reanalyses.
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CLIVAR Ocean Reanalysis Workshop

• Climate relevant applications of ocean reanalysis
  include
• 1) Understanding climate dynamics from
  reanalyses.
• 2) Reanalysis, sea level rise and 5th IPCC
  assessment.
• 3) CO2 sequestering.
• 4) Regional impacts.
• 5) Initializing coupled models from ocean
  reanalyses.
• 6) Observing System Experiments (OSE) need to be
  carefully prepared and evaluated.
• CLIVAR GSOP should promote a wider use of
  reanalysis result for science and societal needs.
• CLIVAR will aim to make reanalysis products
  available in 2009 in time to contribute to the
  5th IPCC Assessment Report.

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CLIVAR Ocean Reanalysis Workshop Issues

• There is not yet a sustained activity to
  address climate-quality hindcasts/reanalyses as
  well as Dec-Cen initialization and anthropogenic
  time-scale projection problems.
• There seems to be a well organized data stream
  for SI efforts that is partially used by other
  ocean reanalyses efforts.
• Testing the existing reanalyses in terms of their
  quality for each of the above requirements is
  urgent. This includes determining uncertainties
  and ensembles. This needs to be done in close
  collaboration with WGOMD, GODAE and the basin
  panels. (model-model model-data prediction,
  residuals)
• Data stream and data QC became large issues for
  decadal reanalysis efforts.
• Surface flux (plus run off and ice volume
  advection) uncertainties remain a large issue.
  Reanalyses efforts need to work with WGOMD on
  identifying useful surface flux products and
  standards in support of ocean reanalysis.

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CLIVAR Ocean Reanalysis Workshop Actions
Underway

• Working group on data quality requirements for
  reanalyses and ocean data systems
• Working group on intercomparison of reanalyses
  (in partnership with GODAE, WGOMD and CLIVAR
  panels). This would initially be done in a pilot
  intercomparison process to be developed in the
  coming year.
• Preparation of recommendations for model
  standards and surface fluxes that should be used
  by reanalysis efforts. To be done in close link
  to CLIVAR-WGOMD and Flux WG.

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Conclusions/Issues

• The goal is an accurate description of the
  current and past state of the complete coupled
  climate system ocean, land, atmosphere,
• Such a description is the product of an analysis
  system
• Ocean Climate Observing System(s) must be
  accompanied by appropriate Climate Analysis
  System(s)
• For NOAAs OCO, the partnership with EMC/CPC is
  an initial step in this direction
• Utilize the analysis system to inform decisions
  on observing system design
• The analysis community has to strive toward a
  coupled system
• Analysis provides the essential link between
  observations and modeling for climate, its
  NOAAs responsibility to figure out how to get it
  done!