Dave Williamson

David Williamson is a Senior Scientist in the Climate and Global Dynamics Division. He has worked on analysis and initialization methods for Numerical Weather Prediction. He has developed numerical methods for global atmospheric models. These include energy conservation aspects of vertical approximations and horizontal approximations over the spherical earth such as finite differences on icosahedral grids, spectral transform methods and semi-Lagrangian methods. He has studied computational aspects of coupling dynamical cores to physical parameterizations. He participated in the development of the successive versions of the atmospheric model that have led up to the current Community Atmosphere Model. He has studied the convergence characteristics of atmospheric simulations with increasing resolution. He has developed and formalized test cases for numerical methods in spherical geometry ranging from simple advection to shallow water equations to baroclinic dynamical cores. These tests are of a deterministic nature. His current interests are on the evaluation of dynamical cores in a forced dissipative equilibrium for climate application. He also developed methods to apply global climate models in forecasts initialized from numerical weather prediction analyses which allow model parameterized variables (e.g. clouds, boundary layer height) to be compared to observations of those variables from field campaigns.