EFFECTS OF N-PROPYL BROMIDE AND OTHER SHORT LIVED CHEMICALS ON STRATOSPHERIC OZONE

A number of the compounds recently being proposed as replacements for substances controlled under the Montreal Protocol have extremely short atmospheric lifetimes, on the order of days to a few months. An important example is n-propyl bromide (nPB). As part of the evaluation of the potential effects of nPB on stratospheric ozone, this study uses the current version of the MOZART three-dimensional model in combination with studies with our less computationally expensive two-dimensional model. Multiple facets of this study examine key questions regarding the amount of bromine reaching the stratosphere following emission of nPB. First, we examine the question of whether tropospheric oxidation of nPB could produce intermediate products that survive long enough to transfer bromine into the stratosphere. Second, we evaluate whether inorganic bromine produced from nPB oxidation in the troposphere could reach the stratosphere in meaningful quantities and thus affect stratospheric ozone. Third, we examine whether the land-based sources of nPB could affect the amount of Br transported to the stratosphere.