Providing microscale emission inputs into the PALM model using the FUME processor

Abstract

The PALM microscale modelling system includes a chemistry module which handles a range of air quality modelling approaches starting from simple passive-tracer simulations to complex chemistry simulations using Kinetic PreProcessor (KPP) based chemistry mechanisms and photolysis employing resolved microscale solar radiation. PALM can directly generate emissions using simple definitions of sources, however for a more complex set of inputs it is beneficial to use a dedicated emissions processor, such as the Flexible Universal processor for Modelling Emissions (FUME). We present the FUME plugin for generating microscale emissions according to the PALM input data standard. Providing emissions for PALM is not without complications. Point sources and other sources with very high spatial gradients may cause artifacts in PALM’s advection schemes, which can be partially mitigated by spatial dispersion of such sources. The emission processor also needs to take into account the geometry of buildings such that the emissions are neither misplaced nor omitted. Using several PALM chemistry simulations, we demonstrate how the PALM FUME plugin avoids these discrepancies.