1. © Crown copyright Met Office Met Office VOCALS activities and interests Phil Brown, Steve Abel and others 29 th July 2008 VOCALS-UK Planning Meeting

2. © Crown copyright Met Office Contents Met Office science interests key observations data exploitation

3. © Crown copyright Met Office Science interests Stratocumulus evolution over land – a significant problem for operational NWP Quasi-equilibrium between multiple physical processes (surface and entrainment fluxes, cloud-top radiative cooling, drizzle) response of BL scheme to changes in surface and large- scale forcing drizzle impact on BL structure and evolution aerosol impacts on drizzle – aerosol physical/chemical properties – potential application of “visibility” aerosol to modulate warm-cloud microphysical process in operational models drizzle impacts on BL turbulence – sub-grid representation of drizzle

4. © Crown copyright Met Office Science interests Description of cloud heterogeneity for cloud-radiation interactions at climate model scales Cloud-radiation studies – operational assimilation of cloud-affected radiances exploitation of simultaneous radiometric and in-situ microphysical measurements to characterize cloud Tomographic microwave measurement of liquid water distribution exploitation of forward/backward scanning capabilities of MARSS in addition to usual zenith/nadir views emphasis on observations from below cloud to exploit cold background views potential future extension to ice/mixed-phase cloud observations with support from airborne cloud radar/lidar

5. © Crown copyright Met Office Why VOCALS? semi-permanent stratocumulus with significant sources of heterogeneity: contrasts between maritime and polluted clouds SST temperature gradients from upwelling and mesoscale eddies diurnal subsidence wave comprehensive observational data set involving all key areas

6. © Crown copyright Met Office which observations? documenting the evolving structure of the BL and its response to forcing and aerosol changes the 20-deg cross-section flights quasi-Lagrangian studies of BL evolution aerosol microphysics and chemistry clean and polluted regions cloud and drizzle microphysics drizzle role in depleting cloud water cloud heterogeneity and POCs drizzle and turbulence structure in the BL fluxes in drizzling and non-drizzling regions coordinated cloud and radiation measurements both overflight and underflight of in-situ measurements

7. © Crown copyright Met Office Exploitation of observations multiple aircraft observations to generate large uniform datasets regular sampling of 20-deg cross-section throughout the field campaign Regional-scale modelling in the presence of steep orography – to provide operational forecasting during the field campaign development of case studies for testing with higher resolution models (UM at 4km and 1.5km or higher resolution, plus increased vertical resolution) LES to study impact of changes in microphysical complexity aerosol nucleation 1- and 2-moment cloud droplets and drizzle interaction between drizzle and dynamical/turbulent structure

8. © Crown copyright Met Office Questions and answers

9. © Crown copyright Met Office MO non-core instrumentation FastFSSP Cloud Imaging Probe (CIP-15) SID-2 Counterflow Virtual Impactor Wet nephelometer ARIES interferometer MARSS microwave radiometer SWS (shortwave spectrometer)