High resolution weather information for plant protection1

Data collected at weather stations are usually used to represent the environmental conditions over the surrounding area (often in the order of 10s or 100s of km²), in spite of differences in elevation, terrain, and other major geophysical factors. We report a method of extending the useful domain of weather data by incorporation of digital terrain data into a model that distributes recorded data over the area surrounding a recording location. Temperature was estimated for each 0.1 km² witnin a 320 km² study area comprising Vestfold county in southern Norway. Estimates were based on correlation analysis and models resulting from comparisons of temperature data from 16 farm locations and temperature recorded at three automatic weather stations, elevation, slope, aspect, proximity to the ocean, and proximity to automatic weather stations. Analysis revealed that local weather could be estimated with greater accuracy than by simply using the values recorded at the automatic stations. Calculation and presentation of the model output can be accomplished with a geographic information system (GIS).