Evaluation of a Simplified Double-Moment Aerosol Scheme (SOL/INSOL) using Synchronous UK Satellite, Airborne and Ground-Based Observations

Oral Presentation 

At present, there is an unsustainable number of aerosol representations in the Met Office’s Unified Model, which cover scales from low resolution climate to high resolution Numerical Weather Prediction (NWP) and air quality models, with little traceability and varying levels of support and development. NWP models are driven by higher resolution initialisation and forcing, which are important to help understand uncertainties associated with coarser resolution climate models, as well as complex chemistry and aerosol microphysical processes at convection and cloud resolving scales. The computational expense of operationally running aerosol schemes at high resolutions is hard to justify meaning more computationally efficient aerosol schemes, that capture an appropriate level of complexity, are needed, particularly for improved simulation of cloud and precipitation microphysics. As such, the SOL/INSOL aerosol scheme has been developed. SOL/INSOL is a single, traceable, double-moment scheme that can be used at all model scales, is intended for NWP simulations and aims to replace MURK as the operational aerosol model for visibility and cloud droplet activation in the UKV. To understand the impact of the simplified scheme and ensure aerosol complexity is balanced with computational efficiency and traceability across spatial and temporal scales, SOL/INSOL has been evaluated with satellite, in-situ airborne, ground and mast observations collected during the SPF Clean Air campaign over the UK.. Here, we introduce the SOL/INSOL aerosol scheme, summarise the results from the ongoing observation evaluation and outline the tuning applied to SOL/INSOL ensure aerosol representation is applicable and appropriate, particularly important in the move to higher resolution models.