Ocean Analysis and Reanalysis:

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• Ocean Analysis and Reanalysis
•  Phil Arkin, ESSIC, University of Maryland
• Background
• Concept and Implementation
• 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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THE GEOSS/IEOS TEMPLATE
Strategic Plan for the Integrated Earth
Observation System Interagency Working Group on
Earth Observations
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What do we do now about the analysis issue?

• 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)
• Utilize the analysis system to inform decisions
  on observing system design
• OCO set up a Team of Experts scientists doing
  research with ocean observations to get started
  on this by using the observations to perform new
  and interesting research

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Team of Experts Goals/Objectives

• Use products from the observing system and other
  sources, including operational and experimental
  analyses, to document the oceans role in climate
  variability and change
• Regularly deliver a suite of ocean products that
  will describe sea level, ocean carbon content and
  its air-sea exchange, SST, surface currents, sea
  surface pressure and air-sea exchanges of heat,
  momentum, and fresh water, ocean heat and fresh
  water content and transports and sea ice
  thickness and concentrations
• Assist the OCO in the development and
  implementation of appropriate quantitative
  performance metrics to evaluate the adequacy of
  the global ocean observing system in meeting the
  following climate goals
• Document long term trends in sea level change
• Document ocean carbon sources and sinks
• Document the oceans storage and global transport
  of heat and fresh water
• Document the ocean-atmosphere exchange of heat
  and fresh water

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Team of Experts Deliverables

• Products analyze the present state of the
  global ocean evaluate how the present state
  compares with the past, including
  confidence/uncertainty updated at least annually.
  Publicly available and understandable by
  decision-makers and non-scientists wherever
  possible.
• Evaluation help test the composite observing
  system against ocean climate variables and make
  recommendations at least annually for the
  evolution of the observing system.
• Summary annual report describe the state of the
  ocean with regard to the parameter(s) being
  analyzed and how the present state compares with
  the past. Contributions to State of the Ocean
  and other reports.
• Performance metrics once developed, calculate
  and report to OCO quarterly and meet NOAA
  requirements.
• Reports Each performance metric project must
  file with OCO, quarterly if appropriate but at
  least annually, reports recommending evolution of
  the observing system and/or better use of
  satellite and in situ data to improve observing
  system performance.

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Progress Report

• Team has been established and has met several
  times by conference call and yesterday
• Added GODAS team (Behringer/Xue) as ex-officio
  members
• Contributed ocean summaries for State of the
  Climate 2005 coordinated by NCDC for publication
  in BAMS
• Contributed Chapter 2 in State of the Ocean
  edited by Joel Levy
• Individual reports to follow in particular,
  relate to GODAS wherever possible
• Issues/questions
• What else should we be doing?
• Course corrections needed?