Effective leaf area index is routinely quantified with optical instruments that measure gap fraction through the probability of beam penetration of sunlight through the vegetation. However, there have been few… More
Tower and aircraft data from a number of field studies are analyzed to: (1) estimate the roughness lengths for local and area-averaged momentum fluxes over various surface types; (2) examine… More
The directional thermal infrared exitance distributions of a 21.5-m-tall leafless deciduous forest were measured using a rotating 7-detector array suspended 33 m above the forest floor. These distributions are presented… More
Rising air temperatures are believed to be hastening heterotrophic respiration (Rh) in arctic tundra ecosystems, which could lead to substantial losses of soil carbon (C). In order to improve confidence… More
To determine factors controlling the carbon dynamics of an intensively managed landscape, we measured net CO2 exchange with the atmosphere using eddy covariance and soil CO2 fluxes using static chambers… More
Leaf area index (LAI) is an important variable for climate modeling, estimates of primary production, agricultural yield forecasting, and many other diverse studies. Remote sensing provides a considerable potential for… More
Ecosystem fluxes of energy, water, and CO2 result in spatial and temporal variations in atmospheric properties. In principle, these variations can be used to quantify the fluxes through inverse modelling… More
Using a helicopter-mounted portable spectroradiometer and continuous eddy covariance data we were able to evaluate the photochemical reflectance index (PRI) as an indicator of canopy photosynthetic light-use efficiency (LUE) in… More
Results of an experiment conducted to quantify the ozone deposition onto a deciduous forest stand in an acid-precipitation-impacted area of Canada are presented and discussed. The ozone deposition data were… More
Land surface heterogeneity over an area of 71 km × 74 km in the lower Walnut River watershed, Kansas, was investigated using models and measurements from the 1997 Cooperative Atmosphere… More