MMS Ozonesonde Wind and Temperature Comparison during CRAVE

1
MMS - Ozonesonde Wind and Temperature Comparison
during CR-AVE

• T.P. Bui, J. Dean-Day, C. Chang, R. Castaneda
• NASA-Ames Research Center
• H. Voemel
• University of Colorado -- CIRES

2
Data Sources

• Profiles of WB-57 MMS 1-Hz U, V, T and P during
  descent to Juan SantaMaria Int Airport
• Vaisala RS-80 radiosonde collected GPS position
  (latitude/longitude), T and P during Ozonesonde
  ascents from Heredia, Costa Rica
• Heredia is in close proximity to Juan SantaMaria
  airport (10km distance separation)
• Sondes launched within 1 hr of WB-57 takeoff or
  landing on 11 flights (10 descents, 1 ascent)

3
Data Specifications

• Meteorological Measurement System
• Static Pressure (/- 0.3 mb)
• Static Temperature (/- 0.3 K)
• Wind Velocity (/- 1.0 m/s)
• Vaisala RS-80 Radiosonde
• Static Pressure (/- 0.1 1.0 mb)
• Static Temperature (/- 0.2 K)
• (Temperature corrected for radiation/ventilation
  effects)
• Combined Uncertainty at same time/location
• Temperature (/- 0.5 K)

4
RS-80 Wind Calculation

• Deriving Horizontal Winds from Sonde
• GPS position (latitude/longitude/altitude)
  reported every 1 - 2 seconds during ascent to
  30km altitude
• Time rates of GPS latitude/longitude define U,V
  midway between GPS altitude levels
• U,V at reported levels estimated from spline
  interpolation of instantaneous U,V to each GPS
  altitude level
• Resulting U,V profiles were highly variable
• Wind profiles subjected to simple vertical
  averaging to remove scales lt 100m (approximately
  20 sec during 5 m/s ascent)

5
Ideal Comparison

• MMS and Sonde BOTH report GPS position
• gt Interpolate MMS data to ozone sonde GPS
  altitude
• gt Minimum temporal/spatial separation
• Ideal conditions for MMSRS80 comparison
• gt All profiles are within 2 hours in time
• gt Spatial separation lt 60 km
• gt In generally horizontal homogeneous
  environment (tropics)

6
(No Transcript)
7
(No Transcript)
8
(No Transcript)
9
(No Transcript)
10
(No Transcript)
11
Comparison Summary

• MMS warmer than RS-80 by 0.30 /- 0.20K
• MMS Wind Velocity slightly lower ( 0.65 m/s)
• but uncertainty is larger than mean differences
• Pressure Difference is within RS-80 max error (1
  mb)
• Sonde pressure is lower by 0.7 mb larger
  uncertainty at lower altitudes scale with
  pressure.