institute for atmospheric science school of earth and environment university of leeds tethered...
DESCRIPTION
UNIVERSITY OF LEEDS Institute for Atmospheric Science SCHOOL OF EARTH AND ENVIRONMENT SkyDoc Balloon Filled with helium Diameter ~3m (inflated) Volume ~20 m 3 Static lift = 12 kg Dynamic lift = 1 45 m s -1 Tether line mass = 6 g m mile of tether available 24 V winchTRANSCRIPT
Institute for Atmospheric ScienceSCHOOL OF EARTH AND ENVIRONMENT UNIVERSITY OF LEEDS
Tethered Soundings & Profiling
Cathryn BirchIan 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
Pum
p
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– CT
2, 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 layerStable BL
A: UTC: 12:00
B: UTC: 10:00
C: UTC: 20:00
A CB