A Particle-in-Cell Method for Numerical Solution of the Atmospheric Diffusion Equation,and Applications to Air Pollution Problems. Volume I.

摘要

The document reports the development and initial applications of a new method for the solution of the turbulent atmospheric diffusion equation. The method,called PICK,is based on the use of Langrangian mass points and is one of a family of Particle-in-Cell techniques for the solution of partial differential equations. The purpose of the study was the development of the PICK method and the demonstration of the method in the solution of evaluation test cases and actual air pollution problems. Test cases for the evaluation of feasibility and accuracy and for comparison to finite difference solutions were conducted with a two-dimensional computer code PICFIC. For actual air pollution studies,the PICK method was used in the three dimensional code NEXUS. The description of NEXUS and its application to the simulation of CO in Los Angeles is given. The NEXUS/P code was developed to solve equations with photochemical terms. NEXUS/P's description and its application to photochemical fog in Los Angeles is described. (Author)