En tillförlitliga model för akustik-gravitaions vågor från vulkanutbrott

Tidsperiod: 2018-01-01 till 2021-12-31

Projektledare: Ken Mattsson

Finansiär: Vetenskapsrådet

Bidragstyp: Projektbidrag

Budget: 2 800 000 SEK

The present project focuses on high-fidelity mathematical and numerical models, in collaboration with Stanford University, to simulate infrasound from a wide range of volcanic activity. The first task is to derive an atmospheric 3D model, based on the linearised Euler equations, that takes into consideration: 1) atmospheric attenuation, 2) wind, 3) variable sound speed, 4) stratification and buoyancy, 5) irregular topography, 6) realistic boundary conditions (BC), and 7) atmospheric forcing from volcanic activity. The irregular topography and ground-conditions will require a carful model consideration of both ground BC and boundary data. We expect this first task to take approximately one year. The second task is to derive a high-order accurate finite difference (FD) method that accurately approximates the high-fidelity atmospheric 3D model. The expected numerical difficulties (referring to stability and accuracy) are the following: 1) FD approximations of the convective terms, that involve variable coefficients (grid-metric and atmospheric data), 2) imposing the BC, 3) imposing the volcano source terms, and 4) to build a high-quality curvilinear grid. We expect this task to take approximately two years. The third task is to incorporate data from a quasi-1D nonlinear eruption code, into the atmospheric source terms. The quasi-1D eruption code is currently being derived in collaboration with Stanford University. We expect this last task be completed during the fourth year.