Tethered Soundings & Profiling
Post on 16-Jan-2016
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Institute for Atmospheric ScienceSCHOOL OF EARTH AND ENVIRONMENT UNIVERSITY OF LEEDS
Tethered Soundings & Profiling
Cathryn Birch
Ian Brooks
UNIVERSITY OF LEEDS
Institute for Atmospheric ScienceSCHOOL OF EARTH AND ENVIRONMENT
Radiosondes
• 6 hourly launches• T, p, RH, wind speed and
direction• Up to about 25km
UNIVERSITY OF LEEDS
Institute for Atmospheric ScienceSCHOOL OF EARTH AND ENVIRONMENT
SkyDoc Balloon• Filled with helium
• Diameter ~3m (inflated) Volume ~20 m3
• Static lift = 12 kg
• Dynamic lift = 1 ton @ 45 m s-1
• Tether line mass = 6 g m-1
• 1.5 mile of tether available
• 24 V winch
UNIVERSITY OF LEEDS
Institute for Atmospheric ScienceSCHOOL OF EARTH AND ENVIRONMENT
Basic system from Gill instrumentsLeeds adding:• custom motion pack + GPS• Mean T, RH, P• CLASP aerosol probe• Control, logging, and comms board• Battery powered – duration ~5 hours
• Turbulence measurements @ 10 Hz• Mean met data @ 1Hz
UNIVERSITY OF LEEDS
Institute for Atmospheric ScienceSCHOOL OF EARTH AND ENVIRONMENT
CLASP instrument Compact Lightweight Aerosol Spectrometer Probe
Pu
mp
Sensing head
25 cm
• 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
UNIVERSITY OF LEEDS
Institute for Atmospheric ScienceSCHOOL OF EARTH AND ENVIRONMENT
winch
Timed photographic record from balloon – lead fraction retrieval, cloud top imagery…
UNIVERSITY OF LEEDS
Institute for Atmospheric ScienceSCHOOL OF EARTH AND ENVIRONMENT
Mean meteorology profiles
T (C) WS (m s-1)RH (%)
Alti
tude
(m
)
UNIVERSITY OF LEEDS
Institute for Atmospheric ScienceSCHOOL OF EARTH AND ENVIRONMENT
SODAR (SOnic Detection And Ranging) – Scintec Phased Array
Provides– Backscatter– 3D mean winds
– CT2, z/L, turbulent dissipation
– Vertical resolution 10 m– 10-min averaged data
• Measures the scattering of sound waves by atmospheric turbulence
UNIVERSITY OF LEEDS
Institute for Atmospheric ScienceSCHOOL OF EARTH AND ENVIRONMENT
Turbulence properties : CT2
Measurements from Africa
Inversion
Entrainment zone
well mixed layer
Stable BL
A: UTC: 12:00
B: UTC: 10:00
C: UTC: 20:00
A CB
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