Vibronic coupling in the superoxide anion: the vibrational dependence of the photoelectron angular distribution.

We present a comprehensive photoelectron imaging study of the O(2)(X  (3)Σ(g)(-),v(')=0-6)←O(2)(-)(X  (2)Π(g),v(")=0) and O(2)(a (1)Δ(g),v(')=0-4)←O(2)(-)(X  (2)Π(g),v(")=0) photodetachment bands at wavelengths between 900 and 455 nm, examining the effect of vibronic coupling on the photoelectron angular distribution (PAD). This work extends the v(')=1-4 data for detachment into the ground electronic state, presented in a recent communication [R. Mabbs, F.

Oxygen isotopic composition of carbon dioxide in the middle atmosphere.

The isotopic composition of long-lived trace molecules provides a window into atmospheric transport and chemistry. Carbon dioxide is a particularly powerful tracer, because its abundance remains >100 parts per million by volume (ppmv) in the mesosphere. Here, we successfully reproduce the isotopic composition of CO(2) in the middle atmosphere, which has not been previously reported.