Next-generation Numerical Weather Prediction Research Articles

Simulation of tropical-cyclone-like vortices in shallow-water ICON-hex using goal-oriented r-adaptivity

We demonstrate how efficient r-adapted grids for the prediction of tropical cyclone (TC) tracks can be constructed with the help of goal-oriented error estimates. The binary interaction of TCs in a barotropic model is used as a test case. We perform a linear sensitivity analysis for this problem to evaluate the contribution of each grid cell to an error measure correlated with the cyclone positions. This information allows us to estimate the local grid resolution required to minimize the TC position error. An algorithm involving the solution of a Poisson problem is employed to compute how grid points should be moved such that the desired local resolution is achieved. A hexagonal shallow-water version of the next-generation numerical weather prediction and climate model ICON is used to perform model runs on these adapted grids. The results show that for adequately chosen grid adaptation parameters, the accuracy of the track prediction can be maintained even when a coarser grid is used in regions for which the estimated error contribution is low. Accurate track predictions are obtained only when a grid with high resolution consisting of cells with nearly constant size and regular shape covers the part of the domain where the estimated error contribution is large. The number of grid points required to achieve a certain accuracy in the track prediction can be decreased substantially with our approach.

MEETING SUMMARIES

WHAT: Scientists from Korea, Japan, and the United States discuss recent developments in the parameterizations of physical processes in nextgeneration, high-resolution numerical weather prediction models WHEN: 17–18 May 2004 WHERE: Yonsei University, Seoul, Korea he Second International Workshop on NextGeneration Numerical Weather Prediction (NWP) Models1 met to discuss the impact of recent developments in modeling for next-generation, high-resolution NWP models, and to exchange ideas for improving the prediction of high-impact weather. In 1999, the Laboratory for Atmospheric Modeling Research (LAMOR) of Yonsei University (YSU) embarked on a national project developing a next-generation NWP model focusing on the parameterization of physical processes in high-resolution models (see information online at http://lamor.yonsei.ac.kr). The ultimate goal of the project is in line with that of the Weather Research and Forecast (WRF) model initiative (see information online at http://wrf-model. org), both of which are to develop a state-of-the-art mesoscale model that is suitable for grid spacing in the range of 1–30 km. The director of LAMOR, Professor Tae-Young Lee, told participants that the focus of this workshop was to discuss the progress in our understanding of the physical parameterizations and the outcome of collaboration between the LAMOR and U.S. groups for the past three years. Major outcomes of collaborations include the Yonsei University PBL (YSUPBL) and WRF single-moment microphysics (WSM) schemes implemented in the WRF model.