BOWEN RATIO SURF. FLUX: FRITSCHEN (FIFE)

Surface flux measurements were made at selected sites within the FIFE area. Each surface flux station was capable of measuring the fluxes of net radiation, sensible heat, and latent heat. The Bowen ratio stations measured the soil heat flux as well. The surface flux and micrometeorological measurements available in this data set were collected from 15 locations within the FIFE study area between 1987 and 1989. Six automatic surface energy and radiation balance systems were operated continuously for 144 days from May 16 to October 16, 1987. Variables including net radiation, air temperature, vapor pressure and wind speed, were quite similar for the sites even though the sites were as much as 10 km apart and represented the four cardinal slopes and a top. The Bowen ratio was low during most of the season, increasing sharply toward the end of the season after a long dry spell. The average Bowen ratio was 0.35. About 72% of the available energy was converted into latent heat flux density. Since the data systems and instrumentation used were of similar design, the variability in results can be ascribed to treatment and locations. These results can be used to estimate the number of stations needed to represent a rolling prairie topography.