1. Observing Climate - Upper Air
Upper-air Measurements
Radiosonde
Rawinsonde
Science Concepts

2. Observing Climate - Upper Air
U.S. Upper-Air Observations
Radiosonde Movie

3. Observing Climate - Upper Air
U.S. Upper-Air
Observations
• Radiosonde
instrument package
- Pressure
- Temperature
- Relative Humidity
• Rawinsonde - Tracked
radiosonde
- Winds

4. Observing Climate - Upper Air
Note drift distance during sonde’s flight, especially in regions of high speed winds denoted by red shading (Isotachs - Contour of wind speed)
Radiosonde
• 2 m (6 ft) wide hydrogen or helium filled balloon filled
• Rises at about 300
m/min (about
1,000 ft/min)
• Tracking position
yields wind speed
and direction -
called a
rawinsonde.
New system will
use GPS
• Flight can last more
than 2 h
• Can ascend to over
35 km (about 115,000 ft) and drift more than 200 km (about 125 miles)
Shipley, S.T, 2005: GIS applications in
meteorology - Or adventures in a parallel
universe. Bull. Amer. Meteor. Soc., 86,

5. Observing Climate - Upper Air
Radiosonde
• When the balloon expands too large (about 6 m or 20 ft in diameter), it bursts
and a small parachute slows the descent minimizing the danger to lives and
property
• Data (temperature, dewpoint
temperature, and wind speed
and direction) is plotted on a
graph (Skew-T Log-p diagram)
depicting the sounding versus
pressure
Temperature
Dewpoint
Temperature
Winds

6. Observing Climate - Upper Air
U.S. Upper-Air Sites

7. Observing Climate - Observing Site
Typical Weather
Service Observing Site
Wind Vane
Cup
Anemometer
Instrument
Tower
Balloon Inflation Shelter
with Radiotheodolite
radome
Rain Gage
Instrument
Shelter