Radiosondes, Rawinsondes, and Profilers

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Radiosondes, Rawinsondes, and Profilers
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• Radiosonde an instrument used to obtain the
  vertical distribution of temperature, pressure,
  and humidity.
• Rawinsonde an instrument used to obtain the
  vertical distribution of temperature, pressure,
  humidity and winds.
• These are small, lightweight boxes
  equipped with weather instruments and a radio
  transmitter.

• The instruments include
• Small electrical thermometer a thermistor
• A hygristor to measure humidity
• An aneroid barometer that measures pressure.

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Rawinsondes are attached to a cord that has a
parachute and gas filled balloon tied to the
end. The Balloons are filled with hydrogen
because it is much cheaper that helium.
http//www.ua.nws.noaa.gov
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During the Launch
Before Launch
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Rawinsonde Site Map
http//www.ua.nws.noaa.gov
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Interesting Facts
Rawinsonde observations are taken twice daily at
0000 hours and 1200 hours Greenwich Mean Time
(GMT), or at 6 pm and 6 am CST. The radiosonde
flight can last in excess of two hours, and
during this time the radiosonde can ascend to
over 35 km (about 115,000 feet) and drift more
than 200 km (about 125 miles) from the release
point. Only about 20 percent of the
approximately 75,000 radiosondes released by the
NWS each year are found and returned to the NWS
for reconditioning. Data on winds, temperatures
and humidity help forecasters predict clouds,
rain and the paths of major storms.
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Wind Profilers
Wind profilers are specifically designed to
measure vertical profiles of horizontal wind
speed and direction from near the surface to
above the tropopause.
http//www.profiler.noaa.gov
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Wind Profiler Facts

• Wind NPN profilers are designed to operate
  reliably and unattended in nearly all
  weather conditions.
• This means that they have a minimum number
  of moving parts.
• 2. Wind profilers are relatively low-power,
  highly sensitive clear-air radars, operating at a
  wavelength of 74 centimeters.
• This does not mean that they can only function
  in clear conditions!!
• 3. The radars detect fluctuations in the
  atmospheric density, caused by turbulent mixing
  of volumes of air with slightly different
  temperature and moisture content.

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The grid in the center of the profiler is the
antenna
http//www.profiler.noaa.gov
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http//www.profiler.noaa.gov
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12 hour Wind Plot