Analysis Error Characteristics

• Assumed Model Background Error
• U and V wind components ~7 m/s (see wind.nl)
• Temperature ~7 Deg C (see temp.nl)
• Depends on instrument error, assumed values are...
  • U and V wind components (see windparms.inc)
    • Surface: 1 m/sec
    • ACARS: 1 m/sec
    • Profiler: 1 m/sec
    • Cloud-drift winds: 5 m/sec
    • Doppler radar: 4.5 m/sec (has more effective weight if large # of obs)

  • Temperature
    • Surface: 1 Deg C
    • ACARS: 1 Deg C
• Depends on subgrid-scale variability
• Representativeness of station location within grid-box
• Depends on data density & distance from stations
• Depends on analysis assumptions

• e.g. radar echoes imply existence of clouds