Measurement of water vapor in the stratosphere by photodissociation with Ly α (1216 Å) light

Abstract

Photodissociation of polyatomic molecules by vacuum-uv light often results in the formation of electronically excited diatomic molecular fragments. Based on this, instruments that measure mixing ratios or densities of selected polyatomic species in the stratosphere and higher troposphere can be constructed. This is demonstrated by an instrument to detect and measure stratospheric water mixing ratios utilizing H2O photodissociation by Ly α (1216 Å) light and detecting OH(A2J +X2Π) emission. Also, detectors for H2O 2, HNO3, and NO2 are discussed.