Cuvette for measuring leaf level fluxes of trace gases. |
The Virginia Forest Research Facility (VFRF) supports a variety of research activities. The 40-meter tower provides a platform for measuring the exchange of scalars and energy between the forest canopy and the overlying atmosphere. An eddy covariance system provides fluxes of momentum, water vapor, sensible heat, and latent heat. A series of radiometers quantify incoming and outgoing radiation over a broad range of spectral bands (PAR, UV, solar, terrestrial). A gas profiling system has intakes at several levels on the tower and is used to sample trace gases and aerosols at within and above the canopy. Fluxes of trace gases (e.g. hydrocarbons, ozone) are measured with a relaxed eddy accumulation system. Some gasses can also be sampled at the leaf level (see cuvette, at left). Soon, an automated trolley instrumented with several radiometers will provide the horizontal distribution of radiation at the forest floor. In particular, the trolley will define horizontal averages of actinic irradiance, which is important to the photolysis of chemical species and thus, atmospheric chemistry. |
