Enviro-HIRLAM Seamless Modelling: Research, Development, Application

The Enviro-HIRLAM (Environment - HIgh Resolution Limited Area Model) is seamless/ online integrated numerical weather prediction and atmospheric chemical transport modelling system. It is capable of simultaneous simulation of meteorology – atmospheric composition and downscaling/nesting for regional–subregional–urban scales. The research and development are focused on: multi-scale modelling up to fine resolution; improving parameterizations describing urban processes, boundary/surface layer structures; implementation of emissions, aerosol/chemistry mechanisms, aerosol feedback and interactions. The Enviro-components includes: gas-phase chemistry; aerosol microphysics and deposition processes; urban sublayer physics parameterisations; direct/indirect/combined aerosol feedbacks due to radiation; locally  mass-conserving  semi-Lagrangian  numerical  advection  scheme; natural and anthropogenic emission inventories. The model has modules for pre-processing of the ECMWF’s initial/ boundary conditions for meteorology-chemistry-aerosols, observations for data assimilation, and selected emission inventories. The model has been developed through HPC projects such as Enviro-HIRLAM at CSC and Enviro-PEEX(Plus) at ECMWF, as well as other research projects.

The research and development of Enviro-HILRAM and its application will be demonstrated on examples, where this model is used as a research tool  for studies in domain of the Pan-Eurasian Experiment (PEEX; https://www.atm.helsinki.fi/peex) programme. The examples include: Integrated modelling for assessment of potential pollution regional atmospheric transport as result of accidental wildfires; Integrated modelling and analysis of influence of land cover changes on regional weather conditions/ patterns; High-resolution integrated urban environmental modelling with integration of the urban large-eddy simulation (PALM model) and meteorological simulations into a seamless modelling chain; Effects of spring air pollution and weather on Covid-19 infection/situation in Finland; Meteorology integration between seamless and trajectory (FLEXPART model) models; and others. The Enviro-HIRLAM model generated output provides valuable input (3D meteorology and atmospheric composition) to assessment studies, and it as can be integrated into GIS environment for further risk/ vulnerability/ consequences/ etc. estimation, and other studies.