Seminário: Tropical disturbances in a hierarchy of models

12/08/2016 - 14:00
Auditório 1 do IAG (Rua do Matão, 1226, Cidade Universitária)

O seminário do Departamento de Ciências Atmosféricas será apresentado por Nick Hall (LEGOS, University of Toulouse, France), em visita ao IAG a convite da Profa. Dra. Maria Assunção Faus da Silva Dias.
Tropical disturbances in a hierarchy of models
In this talk I will present a range of model experiments that look at the response of propagating tropical modes to extratropical variability, and the importance of the tropical large scale flow and interactions with diabatic heating. To do this we use a fully featured regional model (WRF) and an idealised GCM (the Reading spectral model). In both cases we will work with realistic climatologies but in the latter case using idealised “diagnostic” modelling. 
Questions we address using WRF are: 
  • to what extent are the extratropical boundary conditions responsible for the amount of intraseasonal variance in the tropics?
  • can knowledge of the extratropical flow contribute to skill in predicting MJO events?
Questions we address using the global primitive equation model are:
  • can we use this model to realistically simulate global dynamics despite its lack of physical processes?
  • what are the dynamical and physical mechanisms necessary for an adequate representation of propagating tropical disturbances?
In order, the answers are: about half; yes but statistical skill is low; yes of course we can and work in progress!