© Crown copyright Met Office Boundary layer research at the UK Met Office Research Unit, Cardington Jeremy Price, Met Office Research Unit, Cardington, Beds.

© Crown copyright Met Office Cardington Activities include:- On site experiments and field trials Off site field trials and deployments Instrument development Instrument inter-comparisons Hosting of 3rd party equipment/projects (e.g. FGAM wind profiler, NCAS activities)

© Crown copyright Met Office Site with cumulus congestus

© Crown copyright Met Office Routine Cardington surface measurements Data logged 24/7 includes:- Full suite of met. parameters up to 50m altitude (measures energy balance) Doppler Lidars, Microwave radiometers Aerosol parameters Over ten years of data logged Data is available via BADC Other significant facilities (not 24/7):- Tethered balloon: operates on IOP basis LUAS system under development Instrumented van

© Crown copyright Met Office Tethered balloon system Balloon:- 1800Cuft Cardington Turbulence probe Cloud droplet probe (DMT)

© Crown copyright Met Office Cardington Instrumented Van Radiosonde capability, RS92s (20 sondes) Halo Doppler Lidar system 14km max range Depolarisation ~1 ray per second. 6-8 hour duration on batteries. Generator option

© Crown copyright Met Office Recent development of a Light Unmanned Aerial System (LUAS) Autonomous flight Lightweight (~3kg) ~30 min duration Ceiling (5000ft +) Airspeed nom. 14m/s Max climb ~1000 ft/min PTU and wind profile flights conducted. Future: validate winds/reduce system noise.

© Crown copyright Met Office Recent experiments: Fog (2006-present) Fog is a ‘high-impact’ weather phenomenon Poorly forecast Evolution of fog and its droplet spectra examined at Cardington (see Price BLM 2011) LES simulations of specific cases (see Porson et al., BLM, 2011) Results show detailed changes in stability and dynamics in fog layers due to altering radiative balance – a challenge for LES Getting correct droplet deposition is key

© Crown copyright Met Office Evolution of stability in fog - examples

© Crown copyright Met Office Profile of Fog liquid water parameters - example

© Crown copyright Met Office Fog spectra – example (at 2m agl) Black: Early, Red: Middle, Green: late, Blue: dissipation, phases

© Crown copyright Met Office Current future priorities at Cardington Stable BL/cold pooling BL clouds, Sc, CuSc Fog In support of developing new / high resolution NWP models, continue with: But also future possible/likely detachments: OPREC orographic precipitation over a hill Tidal meteorology – esturine fluxes/turbulence COLPEX2 Wind energy projects

© Crown copyright Met Office Summary BL issues still of major importance for forecast accuracy The appearance of new, high resolution numerical models requires their validation and development with, new, high resolution observations. Such measurements are challenging and will often require the whole energy balance/BL to be sampled in order to deduce results, requiring a comprehensive and collaborative approach. New, or improving instrumentation allows better/complementary ways to examine the atmosphere

© Crown copyright Met Office Questions?