0000000000335297
AUTHOR
V. Bense
In situ observations of CH2Cl2 and CHCl3 show efficient transport pathways for very short-lived species into the lower stratosphere via the Asian and the North American summer monsoon
Efficient transport pathways for ozone-depleting very short-lived substances (VSLSs) from their source regions into the stratosphere are a matter of current scientific debate; however they have yet to be fully identified on an observational basis. Understanding the increasing impact of chlorine-containing VSLSs (Cl-VSLSs) on stratospheric ozone depletion is important in order to validate and improve model simulations and future predictions. We report on a transport study using airborne in situ measurements of the Cl-VSLSs dichloromethane (CH2Cl2) and trichloromethane (chloroform, CHCl3) to derive a detailed description of two transport pathways from (sub)tropical source regions into the ext…
Organic and inorganic bromine measurements around the extratropical tropopause and lowermost stratosphere: insights into the transport pathways and total bromine
We report on measurements of total bromine (Brtot) in the upper troposphere and lower stratosphere taken during 15 flights with the German High Altitude and LOng range research aircraft (HALO). The research campaign WISE (Wave-driven ISentropic Exchange) included regions over the North Atlantic, Norwegian Sea, and northwestern Europe in fall 2017. Brtot is calculated from measured total organic bromine (Brorg) added to inorganic bromine (Bryinorg), evaluated from measured BrO and photochemical modeling. Combining these data, the weighted mean [Brtot] is 19.2±1.2 ppt in the northern hemispheric lower stratosphere (LS), in agreement with expectations for Brtot in the middle stratosphere (Enge…