Past, present, and future modeled ozone trends with comparisons to observed trends

摘要: The NASA Goddard Space Flight Center (GSFC) two-dimensional (2-D) model of stratospheric transport and photochemistry has been used to predict ozone changes that have occurred in the past 20 years from anthropogenic chlorine bromine emissions, solar cycle ultraviolet flux variations, changing sulfate aerosol abundance due several volcanic eruptions including major El Chichon Mount Pinatubo, proton events (SPEs), galactic cosmic rays (GCRs). same linear regression technique derive profile total trends both measurements GSFC model. Derived 2-D are similar shape Solar Backscattered Ultraviolet (SBUV) SBUV/2 with highest percentage decreases upper stratosphere at latitudes. general magnitude derived negative trend is larger than observations, especially northern hemisphere. lower middle latitudes less measured trend. small tropics high latitudes, a pattern very Total Ozone Mapping Spectrometer (TOMS) trends. differences between TOMS generally within 1–2% hemisphere tropics. more southern by 2–4%. Our predictions also compared temporal variations averaged 65°S 65°N over observing period (1979–1993). Inclusion increases, area into our captures much observed global changes. simulations decrease about 4% 1979 1995 increases. abundances were computed significantly affect result maximum 2.8% 1992 annually almost (AAGTO) 65°N. calculated provide moderate perturbation AAGTO ±0.6% (about 1.2% minimum). Effects SPEs relatively small, predicted 0.22% 1990 after extremely large October 1989. GCRs cause minuscule + 0.02% cycle.