ICON-ART
The ICOsahedral Nonhydrostatic model with Aerosols and Reactive Trace gases (ICON-ART) is an open-source atmospheric transport model used in our group for three main applications as outlined below. ICON is an atmospheric model for weather, climate and environmental prediction running from global to local scales. The main developers are the German Weather Service DWD and the Max Planck Institute for Meteorology (MPI-Meteorology) with growing contributions by Swiss partners from the Center for Climate Systems Modeling (C2SM) including ETH and MeteoSwiss. ART is an extension for the simulation of any type of tracers and especially for aerosols and reactive trace gases. ART is mainly developed by the Karlsruhe Institute of Technology (KIT) with contributions by other partners including Empa.
Application in inverse modelling
The first application of ICON-ART in inverse modeling of GHG emissions with CTDAS was done by Michael Steiner (et al. 2023).
For this purpose, he extended ICON-ART with modules for efficient handling of emissions and online (i.e., during runtime) generation of the ensemble of perturbed fluxes and with a nudging scheme to keep the simulations close to analyzed meteorology. He then used it for constraining European anthropogenic CH4 emissions for individual countries with observations from a European observation network. Later, ICON-ART-CTDAS framework was further developed to be used for CO2 anthropogenic and biogenic flux inversions at European and urban scales. Other developments include running inversions with a different framework – Community Inversion Framework (CIF).
Applications in air quality modeling
One of the key features of ICON-ART is the use of the atmospheric chemistry module MECCA as an external preprocessor, which allows incorporating a custom chemistry mechanism. In our group we use the latest MOZART tropospheric chemistry scheme by Emmons et al. to compute full gas-phase chemistry. In addition to MECCA-based chemistry, ICON-ART includes state-of-the-art modules for aerosol dynamics (AERODYN), gas-aerosol interactions (ISORROPIA 2 for secondary inorganic aerosols), and biogenic and natural emissions (MEGAN 2.1 for VOCs, Lundgren et al. 2010 for sea salt, Vogel et al. 2006 for dust). Anthropogenic emissions are integrated into the model system using the Online Emissions Module.
Applications in urban climate modeling
As part of the urban climate modeling applications in our group, through the project UrbaNature, funded by the GAW-GCOS program of MeteoSwiss, we aim to help enhance thermal comfort of residents and reduce CO2 levels in cities by studying the impact of street trees in two pilot Swiss cities. Our approach uses advanced weather and climate models like the ICON-ART as well as urban parameterizations like Terra_Urb (Wouters et al., 2016) and Building Effect Parametrization with Trees (Bep-Tree; Krayenhoff et al., 2020), alongside the CO2 model VPRM (Mahadevan et al., 2008), to simulate greenhouse gas exchanges.
Fig. 2: Figure showing the representation of spatial and area-averaged urban heat island (UHI) in Zurich city defined as the difference between ICON simulations with Terra_Urb and without Terra_Urb. Based on different land use-land cover (LULC) data employed (Globcover2009, Corine 2018, and Modified Corine 2018) the extent and magnitude of UHI changes.
Fig. 3: Figure showing the physical processes embedded in the BEP-Tree model which was coupled to COSMO model in our group (Mussetti et al., 2020). The upcoming coupling of the multi-layer urban canopy model (UCM) BEP-Tree with the ICON model as part of the developments in the UrbaNature project extends the existing (BEP) model by incorporating street trees
