MESA+ University of Twente
Mathematics of Computational Science

Hamiltonian-based numerical Methods for forced-dissipative climate prediction

Hamiltonian-based numerical methods for forced-dissipative climate prediction

Organization:

Funded by: NWO

PhD: Bob Peeters

Supervisor: Onno Bokhove 

Collaboration: Jason Frank (CWI, UvA)

Description:

In this project we assess the behavior of (idealized) climate models which have a Hamiltonian discretization in the limit of no forcing and dissipation. We believe that such type of discretizations lead to better climate predictions. This objective is investigated in two ways: 

1.

Difference in performance between Hamiltonian and conventional non-Hamiltonian based numerical discretizations for simplified low-order models.

2.

Construction of a hydrostatic stratified model on the sphere based on a symplectic Hamiltonian particle-mesh method (HPM) and finite-element method (FEM).

http://aacs.ewi.utwente.nl/AACS/Finished__Projectpage_Hamiltonian-based_numerical_methods_for_forced-dissipative_climate_prediction_files/droppedImage.jpgAdiabatic flow becomes two-dimensional when expressed in isentropic coordinates. This simplifies the Hamiltonian description and discretization of the hydrostatic flow (away from the boundaries, where isentropes may intersect).

http://aacs.ewi.utwente.nl/AACS/Finished__Projectpage_Hamiltonian-based_numerical_methods_for_forced-dissipative_climate_prediction_files/droppedImage_1.jpg

Particle trajectories under small-amplitude wave flow in a static atmosphere, shown for three different isentropic (S) levels. Dots are computed particle vertical (Z) positions from the HPM-FEM code: HPM in horizontal direction, FEM in entropic direction.

Publications:

Papers:

Conference items:

2nd meeting of Wave-flow Interactions, a network in mathematics, Edinburgh 25-29 May 2009,presentation

Posters:

EGU General Assembly Vienna, 2007, Hamiltonian-based numerical methods for forced-dissipative climate prediction