Open AccessResponse of summertime odd nitrogen and ozone at 17 mbar to Mount Pinatubo aerosol over the southern midlatitudes: Observations from the Halogen Occultation Experiment
Author(s) -
Mickley L. J.,
Abbatt J. P. D.,
Frederick J. E.,
Russell J. M.
Publication year - 1997
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/97jd01566
Subject(s) - ozone , aerosol , atmospheric sciences , stratosphere , occultation , middle latitudes , atmosphere (unit) , ozone depletion , environmental science , altitude (triangle) , atmospheric chemistry , ozone layer , sulfate aerosol , climatology , meteorology , geology , geography , physics , geometry , mathematics , astronomy
Observations of stratospheric NO, NO 2 , and O 3 from the Halogen Occultation Experiment (HALOE) are examined over the southern midlatitudes (35°–45°S) in the summers following the eruption of Mount Pinatubo, from early 1992 through mid‐1995. The tracers HF and CH 4 , also observed by HALOE, are used to distinguish between the effects of chemistry and those of transport processes on the distribution of total reactive nitrogen (NO y ) and ozone. Results show that at 17 mbar (about 28 km), in parcels of similar photochemical age, the abundances of summertime NO + NO 2 (NO x .) increased dramatically between 1992 and 1993 and then leveled off in subsequent years. The 1992–1993 increase is coincident in time with a sharp drop in aerosol surface area density as the Pinatubo aerosol cleared the atmosphere and gives evidence of the sensitivity of NO x to sulfate aerosol even at these altitudes, where the cycling of NO y through HNO 3 is rapid. Results also show that summertime ozone abundances at 17 mbar declined by nearly 10% between 1992 and 1993 and then, like NO x , remained about constant for the next three summers. The trend in ozone is opposite in sign to that observed at lower altitudes in the aftermath of the Pinatubo eruption and demonstrates the importance of the NO x catalytic cycles in the ozone loss budget above 26 km.