Laser fast-scanning multipath absorption: an ultrasensitive technique for monitoring tropospheric trace gases

摘要

Abstract: An absorption method for the monitoring of tropospheric trace gases is presented which is based on the fast scanning of a laser system. The 1 km absorption path is folded by a 6 m White cell with an open path set up. In situ measurements of tropospheric OH have been carried out under different environmental conditions. Due to the small dimensions of the volume under study a controlled variation of the photon flux density can be realized. This `open air laboratory' allows kinetic measurements of tropospheric photochemistry under field conditions. !7