Sulfate aerosol concentrations in the stratosphere have been measured for 11 years (1971–1981) using portions of filters collected by the Department of Energy's High Altitude Sampling Program. Data collected seasonally at altitudes between 13 km and 20 km spanning latitudes from 75°N to 51°S are reported. These data are compared with the reported altitudes of volcanic eruption plumes during the same decade. From this comparison it is concluded that (1) several unreported volcanic eruptions or eruptions to altitudes higher than reported did occur during the decade, (2) the e‐fold removal time for sulfate aerosol from the stratosphere following the eruption of Volcan Fuego in 1974 was 11.2±1.2 months, (3) the volcanic contribution to the average stratospheric sulfate concentration over the decade was greater than 50%, and (4) there may be evidence for an anthropogenic contribution to stratospheric sulfate that increases at the rate of 6 to 8% per year.

A total halogen collection system employing ultra‐pure activated charcoal traps has been developed for use in the stratosphere aboard aircraft and balloon sampling platforms. Neutron activation techniques for low‐level chlorine, bromine, and iodine analysis within the activated charcoal sampling matrix were developed. Initial results from six aircraft flights and one balloon mission in the lower stratosphere are presented for latitudes ranging from 16°N to 67°N. Little variability was observed in twelve total, gaseous and particulate chlorine (Cltot) determinations as a function of latitude at 20 km with values ranging between 2.7 ± .9 ppbv and 3.2 ± .7 ppbv. Five total bromine (Brtot) values showed substantial variability ranging from 7 ± 4 pptv to 40 ± 11 pptv. No iodine was observed in any samples but a calculated Itot upper limit of < 3 pptv was determined.

A technique for capturing stratospheric hydrogen halides has been developed using base‐impregnated filters. The method has been shown to have high collection efficiency both in aircraft and balloon sampling. Early measurements of HCl, HBr, and particulate Cl and Br are given.

No abstract

A method for efficient collection of stratospheric hydrogen chloride has been developed. Initial measurements for HCl, HBr and particulate Cl and Br are given.