GPSRO Usage at Environment Canada

Models assimilating RO

  • Global Deterministic (GD):
    • horiz: 1025×800 latlon
    • vertical: 81L hybrid
    • forecasts: 00Z (to 240h) and 12Z (to 180h)
  • Global Ensemble (GE):
    • horiz: 800×400 latlon
    • vertical: 75L hybrid
    • forecasts: 00Z (to 240h) and 12Z (to 180h)
  • Regional (North America) Deterministic (RD):
    • horiz: 978×1010 tilted
    • vertical: 58L hybrid
    • forecasts: 00Z and 12Z to 48h
    • 06Z and 18Z to 54h
  • Regional (North America) Ensemble (RE):
    • horiz: 600×635
    • vertical: 50L hybrid
    • forecasts: 00Z and 12Z to 72h

 Data assimilation method

  • Global Deterministic: 4d , 4/day, 6h (+/- 3h)
  • Global Ensemble: enkf, 4/day, 6h (+/- 3h)
  • North America Deterministic: 3d , 4/day, 4.7h (-3h to +1h40m)
  • North America Ensemble: no assimilation
  • Cutoff times (from synoptic times):
Synoptic time 00Z 06Z 12Z 18Z
Early_short global 2h30 N/A 2h30 N/A
Early_long global 3h05 N/A 3h05 N/A
Late global 9h 6h 8h15 6h

RO quantity assimilated

  • Refractivity
  • 1D operator
  • Tangent point drift not included
  • Vertical thinning: 1 datum/ vertical km
  • RO is not bias-corrected
  • RO is anchor to radiances (which do have dynamic bias correction)

 Observation error characteristics

  • Dynamically determined within each profile from its (O-B) shape


  • 2nd largest impact/datum (after RS)