A critical review of stratospheric chemistry research in the U.S.: 1991–1994

Abstract

After the previous review [Brune, 1991] of the breadth of scientific activity following reports of an ozone hole over Antarctica and of similar photochemistry over the Arctic, it is surprising to find as rich a literature base for this review. Admittedly, some of the recent publications are new, but belated, reports of studies carried out before 1991, while some are results of ongoing studies. However, there have also been important new developments in stratospheric chemistry, many of which were initiated by the long‐awaited launch of the Upper Atmosphere Research Satellite (UARS) [Reber, 1993], the Second Airborne Arctic Stratospheric Expedition (AASE II) [Anderson and Toon, 1993], the European Arctic Stratospheric Ozone Expedition (EASOE) [Pyle et al, 1994], the NASA High‐Speed Research Program (HSRP) [Albritton et al, 1993], the eruption of Mount Pinatubo [McCormick, 1992], and the Stratospheric Photochemistry, Aerosols, and Dynamics Expedition (SPADE) [ Wofsy et al, 1994]. The review period was also highlighted by observations of the lowest global ozone abundances on record [Gleason et al, 1993], detection of enhanced ultraviolet radiation at the earth's surface [Frederick and Alberts, 1991], examinations of possible strategies for mitigating ozone losses [Cicerone et al, 1991], and direct confirmation of the effectiveness of international agreements limiting the production of ozone‐destroying substances [Elkins et al, 1993].

Climate/chemistry effects of the Pinatubo volcanic eruption simulated by the UIUC stratosphere/troposphere GCM with interactive photochemistry

“…Analyses of the gaseous composition of the atmosphere during the post‐Pinatubo period have been presented in many publications (see the extensive reviews by Solomon [1999] and Toohey [1995]). The most important chemical processes in the post‐Pinatubo atmosphere are connected with the presence of liquid sulfate aerosol, which provides a medium for heterogeneous reactions.…”

Untitled

“…The high aerosol load present just after the eruption in mid-1991 changed stratospheric heating and hence reduced tropical ozone through dynamical effects [Brasseur and Granier, 1992], but this lasted only a few months and was largely confined to the tropics [see Schoeberl et al, 1992b;Tie et al, 1994]. For reviews of the many studies establishing the large and persistent midlatitude ozone changes after Pinatubo, see Toohey [1995] and WMO/UNEP [1994,1998]. Because the stratospheric Brewer-Dobson circulation (as depicted in Figure 2) transports material upward and poleward, major volcanic eruptions that inject material into the tropical stratosphere can have the greatest and longest impacts on global ozone, while volcanic injections at higher latitudes are removed by downward motion.…”

Photodissociation dynamics of CBr4 at 267nm by means of ion velocity imaging

“…Some source gases that contribute to the total bromine budget in the stratosphere and tropical tropopause are bromoform ͑CHBr 3 ͒, methyl bromide ͑CH 3 Br͒, and dibromomethane ͑CH 2 Br 2 ͒. 6 Previous studies of the photodissociation of CBr 4 at 193 and 248 nm ͑Refs. Laboratory research and stratospheric measurements suggest that one bromine atom has the potential of destroying 40-100 times more stratospheric ozone molecules than a chlorine atom.…”