Evidence for HBr production due to minor channel branching at mid‐latitudes

Partitioning between the inorganic chlorine reservoirs HCl and ClONO<sub>2</sub> during the Arctic winter 2005 from the ACE-FTS

“…The photochemical calculations have been done with a box model (Chartrand and McConnell, 1998) with updated rate data including heterogeneous chemistry on ice and STS polar stratospheric clouds. STS is assumed to grow on sulfate aerosols, which have a fixed climatological distribution.…”

Ground‐based measurements of ozone and NO2during MANTRA 1998 using a Zenith‐sky spectrometer

“…13 (based on NO 2 columns of approximately 3.8 × 10 15 molecules cm -2 at sunrise and approximately 5.8 × 10 15 molecules cm -2 at sunset). A box model having a comprehensive chemical scheme and accurate photolysis rates (Chartrand and McConnell, 1998) predicts a sunrise/sunset ratio of 0.60 for the NO 2 vertical columns given initial conditions appropriate for the MANTRA 1998 campaign, a value that is comparable with the measured ratio.…”

An introduction to stratospheric chemistry: Survey article

“…For example, while HCl is formed through the reaction of CH 4 with atomic chlorine, the same reaction for Br is endothermic and extremely slow. HBr then must be formed predominately through the reaction of Br with HO 2 , HCHO or through the minor branch of BrO + OH (Chartrand and McConnell, 1998). Also, HBr is much more photolytic than is HCl: the photolysis constant for HCl is 2.9 × 10 -9 s -1 while for HBr it is 2.0 × 10 -7 s -1 for a directly overhead sun at 20 km altitude.…”

“…Bromine species are present in the stratosphere as well but concentrations reach only approximately 20 pptv in the mid-to upper stratosphere (Chartrand and McConnell, 1998). However, a particular amount of total bromine is much more effective at destroying ozone than is the same amount of total chlorine.…”