Group seminar on 28. June, 14:15 CET

On scale interactions and climate change in a Lorenz-2005 model

Verena Jung

In climate science toy models are used to reduce computational effort and complexity to study certain process characteristics. In this ongoing master thesis work a version of the two scales Lorenz 2005 model (LM05-IIIa) is used as a toy model describing the climate system. The original LM05-III model version was designed to mimic multi-scale atmospheric dynamics along a latitude circle. Dynamics is defined by an ordinary differential equation system that consists of quadratic terms, linear terms and a constant term which can be interpreted as advection, dissipation and forcing respectively. The variables of the model represent large-scale and small-scale processes and are coupled. The first part of the talk will present the model design to allow a study of scale interactions using spectral analysis. Thereafter the model behavior will be discussed for different constant forcing. The change of the model climate due to time-dependent forcing is investigated in spectral space to determine the spatial scales and time scales of the model variability affected by time-dependent forcing.