A search for relativistic electron induced stratospheric ozone depletion

Possible ozone changes at 1 mb associated with the time variation and precipitation of relativistic electrons are investigated by examining the NIMBUS 7 SBUV ozone data set and corresponding temperatures derived from NMC data. No ozone depletion was observed in high-latitude summer when temperature fluctuations are small. In winter more variation in ozone occurs, but large temperature changes make it difficult to identify specific ozone decreases as being the result of relativistic electron precipitation

Polar Ozone Workshop. Abstracts

Results of the proceedings of the Polar Ozone Workshop held in Snowmass, CO, on May 9 to 13, 1988 are given. Topics covered include ozone depletion, ozonometry, polar meteorology, polar stratospheric clouds, remote sensing of trace gases, atmospheric chemistry and dynamical simulations

The threee-dimensional morphology of the Antarctic ozone hole

The three-dimensional morphology of the spring antarctic ozone distribution as determined by the Nimbus 7 Solar Backscatter Ultraviolet (SBUV) spectrometer instrument is presented for the period 1 to 11 October in 1986. The data show that a clearly defined minimum in ozone relative to the local ozone field extends throughout the stratosphere from the tropopause to above 50 km, though decreasing in intensity with altitude. Near 18 km ozone in the ozone hole is 50 percent less than the average surrounding ozone. But even at 50 km the ozone is 20 percent less than the surrounding ozone field. The ozone minimum in the upper stratosphere is displaced about 6 degrees toward the equator so that observations at a fixed station may provide the illusion that the ozone minimum is restricted only to low altitudes. While the ozone minimum is spatially coherent throughout the stratosphere, there are differences in the behavior of ozone at different altitudes that suggest the existence of at least three distinct altitude domains. Below 30 km ozone is characterized by classic ozone hole behavior. Between 33 and 43 km ozone is more stable, actually increasing during September and October. Above 43 km ozone has always decreased during September to a minimum in October, but it has suffered a long term decrease of 7 to 12 percent since 1979 similar to that seen at low altitudes

In Situ Measurements of Meteoric Ions

Metal ions found in the atmosphere above 60 km are the result of incoming meteoroid atmospheric ablation. Layers of metal ions are detected by sounding rocket in situ mass spectrometric sampling in the 80 to 130 km region, which coincides with the altitude region where meteors are observed. Enhancements of metal ion concentrations occur during meteor showers. Even outside of shower periods, the metal ion altitude profiles vary from measurement to measurement. Double layers are frequent at middle latitudes. More than 40 different meteoric atomic and molecular ions, including isotopes, have been detected. Atmospheric metal ions on average have an abundance that matches chrondritic material, the same composition as the early solar system. However there are frequently local departures from this composition due to differential ablation, species dependent chemistry and mass dependent ion transport. Metal ions react with atmospheric O2, O, O3, H2O and H2O2 to form oxygenated and hydrogenated ionic compounds. Metal atomic ions at high altitudes have long lifetimes. As a result, these ions, in the presence of Earth's magnetic field, are transported over long distances by upper atmospheric winds and ionospheric electric fields. Satellite measurements have detected metal ions as high as, approximately 1000 km and have revealed circulation of the ions on a global scale

Atmospheric Effects of Biomass Burning in Madagascar

Simultaneous tropospheric ozone and aerosols observed using the TOMS satellite instrument are reported for Madagascar during the 1979 through 1999 time period Ozone observations made using the TOMS tropospheric ozone convective-cloud differential method show that the tropospheric ozone amount associated with Madagascar has an average monthly value of 30 DU (Dobson units). The average value is enhanced by 10 to 15 DU in October This maximum coincides with the time of maximum biomass area burning in Madagascar and parts of southern Africa. The aerosol index derived from TOMS is examined for correlation with biomass burning in Madagascar and southern Africa. There is good correlation between a satellite observation derived fire index for different parts of Madagascar, tropospheric ozone and the TOMS aerosol index in the same geographical area. Aerosols from fires were found to reach their peak in November and to persist over Madagascar until sometime in December