Tethered%20Soundings%20

1
Tethered Soundings Profiling

• Cathryn Birch
• Ian Brooks

2
Radiosondes

• 6 hourly launches
• T, p, RH, wind speed and direction
• Up to about 25km

3
SkyDoc Balloon

• Filled with helium
• Diameter 3m (inflated) Volume 20 m3
• Static lift 12 kg
• Dynamic lift 1 ton _at_ 45 m s-1
• Tether line mass 6 g m-1
• 1.5 mile of tether available
• 24 V winch

4

• Basic system from Gill instruments
• Leeds adding
• custom motion pack GPS
• Mean T, RH, P
• CLASP aerosol probe
• Control, logging, and comms board
• Battery powered duration 5 hours

• Turbulence measurements _at_ 10 Hz
• Mean met data _at_ 1Hz

5
CLASP instrument Compact Lightweight Aerosol
Spectrometer Probe

• 16 channels - 0.24 to 18.5 ?m diameter
• Flow rate 3 l/min high sampling statistics
  allows 10 Hz temporal resolution collocation
  with sonic anemometer
• Compact (25 x 8 x 6 cm), robust, inexpensive
  short inlet tube and low flow distortion,
  installation in balloon/buoy instrument package
  and mounted on masts

6
winch
Timed photographic record from balloon lead
fraction retrieval, cloud top imagery
7
Altitude (m)
T (C)
WS (m s-1)
RH ()
Mean meteorology profiles
8
SODAR (SOnic Detection And Ranging) Scintec
Phased Array

• Measures the scattering of sound waves by
  atmospheric turbulence

• Provides
• Backscatter
• 3D mean winds
• CT2, z/L, turbulent dissipation
• Vertical resolution 10 m
• 10-min averaged data

9
Turbulence properties CT2 Measurements from
Africa
A UTC 1200
C UTC 2000
B UTC 1000