Fast Time Response Tunable Diode Laser Measurements of Atmospheric Trace Gases for Eddy Correlation

A fast-response, atmospheric trace gas monitor, based on the principle of tunable diode laser absorption spectroscopy, has been developed for making eddy correlation measurements of dry deposition fluxes. This system, which is capable of detecting many trace gases of interest with high sensitivity and selectivity, has been demonstrated to have a response time of 0.3 sec. The monitor was tested under field conditions (both summer and winter) and shown to have adequate sensitivity and time response for eddy correlation. The system has been tested for NO sub(2) and SO sub(2) . Possibilities for additional improvements are discussed.