1. Institute for Atmospheric Science SCHOOL OF EARTH AND ENVIRONMENT UNIVERSITY OF LEEDS Tethered Soundings & Profiling Cathryn Birch Ian Brooks

2. UNIVERSITY OF LEEDS Institute for Atmospheric Science SCHOOL OF EARTH AND ENVIRONMENT Radiosondes 6 hourly launches T, p, RH, wind speed and direction Up to about 25km

3. 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 ton @ 45 m s -1 Tether line mass = 6 g m -1 1.5 mile of tether available 24 V winch

4. UNIVERSITY OF LEEDS Institute for Atmospheric Science SCHOOL OF EARTH AND ENVIRONMENT 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 @ 10 Hz Mean met data @ 1Hz

5. UNIVERSITY OF LEEDS Institute for Atmospheric Science SCHOOL OF EARTH AND ENVIRONMENT CLASP instrument Compact Lightweight Aerosol Spectrometer Probe Pump 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

6. UNIVERSITY OF LEEDS Institute for Atmospheric Science SCHOOL OF EARTH AND ENVIRONMENT winch Timed photographic record from balloon – lead fraction retrieval, cloud top imagery…

7. UNIVERSITY OF LEEDS Institute for Atmospheric Science SCHOOL OF EARTH AND ENVIRONMENT Mean meteorology profiles T (C)WS (m s-1)RH (%) Altitude (m)

8. UNIVERSITY OF LEEDS Institute for Atmospheric Science SCHOOL OF EARTH AND ENVIRONMENT SODAR (SOnic Detection And Ranging) – Scintec Phased Array Provides –Backscatter –3D mean winds –C T 2, z/L, turbulent dissipation –Vertical resolution 10 m –10-min averaged data Measures the scattering of sound waves by atmospheric turbulence

9. UNIVERSITY OF LEEDS Institute for Atmospheric Science SCHOOL OF EARTH AND ENVIRONMENT Turbulence properties : C T 2 Measurements from Africa Inversion Entrainment zone well mixed layer Stable BL A: UTC: 12:00 B: UTC: 10:00 C: UTC: 20:00 A C B