1. General Model Information
Name: Weather Generator
Main medium: air
Main subject: meteorology,hydrology
Organization level: landscape
Type of model: Markov chain, not specified
Keywords: atmospheric, weather simulation, stochastic, first-order Markov-chain probabilities, gamma distribution
For the BASIC version: Clayton Hanson ARS-USDA NW Watershed Res. Center 800 Park Blvd. Plaza IV Suite 105 Boise ID 83712-7716
WGEN (Weather Generator) is a weather simulation model developed by
Richardson at the USDA-ARS Grassland, Soil and Water Research Laboratory
(Richardson and Wright, 1984). It can be used to generate daily values
of maximum and minimum temperatures, precipitation and solar radiation.
The model can generate these values stochastically for time periods ranging
from days to hundreds of years.
The model uses an input file that contains information about first-order
Markov chain probabilities for successive daily precipitation on a monthly
basis, and monthly gamma distribution shape and scale parameters. The user
can run the model using precipitation information to generate the other
three variables or generate all four variables.
Author of the abstract:
CIESIN (CONSORTIUM FOR INTERNATIONAL
EARTH SCIENCE INFORMATION NETWORK)
There is a newer version of WGEN, in the form of a model written in
BASIC with a User Manual:
Hanson, C.L., K.A. Cumming, D.A. Woolhiser, and C.W. Richardson, "Microcomputer
Program for Daily Weather Simulation in the Contiguous United States."
USDA Agricultural Research Service, Publication ARS-114, July 1994, 38
II. Technical Information
Operating System(s): The software is available from the address above. The cost is $(US) 50.
Programming Language(s): FORTRAN/BASIC
III. Mathematical Information
Richardson, C.W., and D.A. Wright. 1984. WGEN: a model for generating daily weather variables. U.S. Department of Agriculture, Agricultural ResearchService, Washington, D.C., ARS-8, 88p. Pickering et al. (1994) WeatherMan: A utility for managing and generating weather data", Agronomy Journal 86:332-337 for a description of a user-friendly version of WGEN and SIMMETEO.
V. Further information in the World-Wide-Web
WGen 1.0 HarnworldWeather Generator
VI. Additional remarks
Global change implications: This model can be used for global changeresearch to assess the impacts of changes in temperature, solar radiationand precipitation on vegetation and soils. Because of its simplistic constructionand fairly reliable estimates, it can be linked to other models, such asCERES-Maize or QB-Maize that require daily weather as driving variables.
Last review of this document by: T. Gabele: Tue Oct 7 1997
Status of the document:
last modified by
Tobias Gabele Wed Aug 21 21:44:52 CEST 2002