RELATIONSHIP BETWEEN WEATHER VARIABLES IN OBSERVED AND WXGEN GENERATED DATA SERIES

In this study, we assess for five selected Canadian climatological sta tions the validity of selected simplifying assumptions used in the Ero sion/Productivity Impact Calculator (EPIC) weather data generator, WXG EN. A useful feature of WXGEN is the small amount of input data requir ed to generate long periods of record. Recent studies have shown some of the deficiencies in WXGEN generated records at selected locations. It is felt that some of the limitations are the result of oversimplifi cation. A primary focus of this study is the failure of WXGEN to accou nt for regional and seasonal differences in the relationship between w eather parameters. It is known that there are pronounced regional and seasonal differences in the relationships between precipitation and da ily average temperature across Canada. We show that data generated wit h WXGEN fails to mimic these regional and seasonal relationships. The question of whether alternatives to stochastic weather data generation may be more appropriate for estimating missing solar radiation data i s addressed. An empirical model based on temperature and precipitation was found to provide better estimates than data from WXGEN. (C) 1998 Elsevier Science B.V.