Multiple equilibria in a coupled ocean–atmosphere–sea ice general circulation model (GCM) of an aquaplanet with many degrees of freedom are studied. Three different stable states are found for exactly the same set of parameters and external forcings: a cold state in which a polar sea ice cap extends into the midlatitudes; a warm state, which is ice free; and a completely sea ice–covered ‘‘snowb...

According to the paradigm of component-based software engineering a software system can be represented as a set of independent reusable modules which communicate with each other.The OASIS team is working on a Grid Component Model (GCM) which defines how a distributed component-based application should be designed, deployed and developed. This work is focused on the modeling aspect of GCM-based ...

Radiative-transfer (RT) is a key component for investigating atmospheres of planetary bodies. With the 3D nature exoplanet being important in giving rise to their observable properties, accurate and fast methods are required be developed meet future multi-dimensional temporal data sets. We develop an open source GPU RT code, gCMCRT, Monte Carlo forward model general use atmosphere problems. aim...

This paper presents the first known application of multi-model ensembles to the forecasting of the thermosphere. A multi-model ensemble (MME) is a method for combining different, independent models. The main advantage of using an MME is to reduce the effect of model errors and bias, since it is expected that the model errors will, at least partly, cancel. The MME, with its reduced uncertainties...

Ongoing controversy about Neoproterozoic Snowball Earth events motivates a theoretical study of stability and hysteresis properties of very cold climates. A coupled atmosphere-ocean-sea ice general circulation model (GCM) has four stable equilibria ranging from 0% to 100% ice cover, including a “Waterbelt” state with tropical sea ice. All four states are found at present-day insolation and gree...