Development of a climate record of tropospheric and stratospheric column ozone from satellite remote sensing: evidence of an early recovery of global stratospheric ozone

摘要

Ozone data beginning October 2004 from the Aura OzoneMonitoring Instrument (OMI) and Aura Microwave Limb Sounder (MLS) are usedto evaluate the accuracy of the Cloud Slicing technique in effort to developlong data records of tropospheric and stratospheric ozone and for studyingtheir long-term changes. Using this technique, we have produced a 32-yr(1979–2010) long record of tropospheric and stratospheric column ozone fromthe combined Total Ozone Mapping Spectrometer (TOMS) and OMI. Analyses ofthese time series suggest that the quasi-biennial oscillation (QBO) is thedominant source of inter-annual variability of stratospheric ozone and isclearest in the Southern Hemisphere during the Aura time record with relatedinter-annual changes of 30–40 Dobson Units. Tropospheric ozone for the longrecord also indicates a QBO signal in the tropics with peak-to-peak changesvarying from 2 to 7 DU. The most important result from our study is thatglobal stratospheric ozone indicates signature of a recovery occurring withozone abundance now approaching the levels of year 1980 and earlier. Thenegative trends in stratospheric ozone in both hemispheres during the first15 yr of the record are now positive over the last 15 yr and withnearly equal magnitudes. This turnaround in stratospheric ozone loss isoccurring about 20 yr earlier than predicted by many chemistry climatemodels. This suggests that the Montreal Protocol which was first signed in1987 as an international agreement to reduce ozone destroying substances isworking well and perhaps better than anticipated.