Report to WCRP Observations and Assimilation Panel

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Towards a GCOS Reference Upper Air Network
Report to WCRP Observations and Assimilation
Panel David Goodrich Director, GCOS Secretariat
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Rationale

• Motivation
• Problems for climate in accuracy, long-term
  stability
• Changes in measurement systems
• Objectives
• Provide long-term, high-quality climate records
• Constrain/calibrate data from more
  spatially-comprehensive global observing systems
  (including satellites)
• Measure large suite of co-related climate
  variables

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Process to Date

• Establish Climate Requirements
• Boulder Workshop 2005
• Participants Climate scientists, data users
• Requirements report prepared
• Assess Instrumentation/Siting Options
• Seattle Workshop 2006
• Participants Instrumentation, network design
  specialists Observing system managers
• Draft report prepared

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• Proposed Observing System Architecture

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Climate Requirements Example
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Proposed Site Instrumentation

• Level 1 (Highest Priority) Measurements
• Standard surface variables (pressure,
  temperature, humidity and wind)
• Redundant / simultaneous measurement of
  temperature and water vapor
• Pressure and GPS / radar height
• Ground-based GPS receivers (column water vapor)
• Level 2 Measurements
• Surface radiation (BSRN suite)
• Microwave radiometer (temperature/moisture
  profile)
• Multi-channel infrared radiometer (such as AERI
  temperature and humidity properties and
  cloud retrieval)
• Integrated trace gas (at least ozone)
  measurements
• Column aerosol measurements from sunphotometers  

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A Potential Model Lindenberg, Germany
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Temporal Sampling Issues for Sondes

• At least some launches at 00 and/or 12 UTC
• Other considerations
• Obtaining daytime, nighttime, dawn and dusk
  observations to span instrument behavior to
  varying radiative conditions
• Adequate sampling of diurnal cycle for some
  places for limited times
• Coincident launch with satellite overpass
• Minimum requirement
• Twice daily with one at 00 or 12 UTC
• Launch at alternating satellite overpass nodes
  one/day cycling through three orbiter
  configuration every six days
• Area of ongoing debate

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Next Steps

• Community Review and Discussion
• Formation of AOPC Working Group
• Consideration by Relevant Panels
• CIMO Management Group
• CBS ET Evolution of Global Observing System
• WOAP
• GCOS Steering Committee
• Coordination with Relevant Observing Systems
• Solicitation of Contributions by Members
• Phased Implementation, Building on
  Existing Sites