Online Cloud Tracking with ICON-TARGO

Object-based studies provide valuable insights into cloud life cycles in atmospheric circulation models. Cloud tracking tools are therefore widely applied but are often limited by data availability and temporal resolution, ranging from minutes to several hours depending on the model application. To address these limitations, we developed TARGO (Targeted Output), an approach that enables cloud detection during the atmospheric model runtime.
TARGO is implemented as a plugin for the ICON model and coupled via the ComIn interface. It employs the TOBAC tracking algorithm for cloud detection and temporal linking at every model time step and allows the targeted output of arbitrary model variables at cloud positions. Alongside cloud number, lifetime, and location, the targeted output enables the analysis of cloud-centred variables such as vertical profiles of mixing ratios, temperature, and wind velocity.
The capabilities of TARGO are illustrated using s set of realistic limited-area simulations of deep convective development, highlighting the benefits of cloud and object tracking on the model time-step level for analysing cloud evolution and sensitivities in ICON.