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Global Ozone: Past and Present

Global Ozone: Past and Present. Abhinand Jha PEP Universität Bremen Presented for Presentation Tech. Course. Overview. 1 Motivation 2 General Introduction 3 Ozone Change Updates 4 Other tracers of O 3 5 Political Scenario 6 Summary. Motivation. Ozone hole's growth rate slows down

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Global Ozone: Past and Present

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  1. Global Ozone:Past and Present Abhinand Jha PEP Universität Bremen Presented for Presentation Tech. Course

  2. Overview 1 Motivation 2General Introduction 3 Ozone Change Updates 4 Other tracers of O3 5 Political Scenario 6 Summary

  3. Motivation Ozone hole's growth rate slows down Scientists credit refrigerant ban U.N. says 'ozone hole' hits record size Antarctica ozone hole grows larger this year 2003 Antarctic Ozone Hole grows fast, But recovery Forecast WMO report 2006

  4. General Introduction Figures from WMO 2006

  5. General Idea Total Ozone column Vertical Ozone column

  6. Chemical and dynamic processes contributing in Ozone variations 1 Solar cycle variations (11 year cycle) 2 QBO (quasi biennial oscillations)(27-month cycle) 3 Volcanic eruptions (effects for few years) 4 EESC (Equivalent effective stratospheric chlorine) More Emphasis on EESC

  7. EESC (Equivalent Effective Stratospheric Chlorine) 1 Ozone-depleting substances release their halogen once they reach the stratosphere. 2 The efficiency for bromine (Br) and chlorine (Cl) in destroying ozone is very high. 3 EESC is a measure of overall stratospheric ozone-depleting halogen.

  8. Ozone change updates

  9. Updated Results Ozone variations for 60o S to 60o N due to different atmospheric processes Elchichon and Mt.Pinatubo • O3 changes can be expressed • In terms of EESC, • Differences between time periods of EESC Scaled and fitted EESC(Eq.Eff.Stratospheric Chlorine) with ozone column Linear Trend Figures from WMO 2006

  10. Statistical Methods 1 Multiple Linear Regression - Try to relate the explanatory variables of ozone to ozone data !!Problem: How proxies are included in the model??? 2 The EESC Function -Analyze changes in ozone (which reflects amount of Cl and Br to deplete O3) !! Problem: Polar EESC is not included

  11. Total Ozone Changes Annual Avarages Annual Avarages 1 Satellite data from Total Ozone mapping Spectrometer (TOMS) 2 Solar backscatter ultraviolet (SBUV) Figures from WMO 2006

  12. Ozone Changes in Tropics 1 Maximum ozone in tropics(40%). 2 Small changes but not statistically significant Ozone column is unchanged at the equator Figures from WMO 2006

  13. Seasonal Ozone variations Ozone Minimum due to volcanic eruptions(Mt.Pinatubo) Clear Difference between NH and SH mid-latitudes. Low due to regular spring time ozone deplition Figures from WMO 2006

  14. Vertical Distribution of Ozone 1 Upper Stratosphere Measured by 1 Ozone Sondes (30-35km) 2 Lidar and Microwave instruments (from lower stratosphere to 50 km) 3 Dobson- Brewer Instruments (ground based profile data up to 50km) 4 Satellite observations (SAGE, SBUV, SBUV/2) Long term decline of ozone till 1996 but then the trend seem to be constant Figures from WMO 2006

  15. 2 Lower Stratosphere Ozone reached minimum values till 1993 but now they are again recovering to the values of early 1980‘s Figures from WMO 2006

  16. 3 Latitudinal Ozone Profiles • Vertically integrated SAGE I+II data,compared with results from the merged TOMS/SBUV column ozone dataset. Tropical differences ….????? Figures from WMO 2006

  17. 4 Tropospheric Ozone (TO) 1 Changes in TO are regional 2 The trends within the region changed over last 25-35 years 43%±25%/decade increase of TO over Delhi Increase of TO over Canada and decrease over Europe and Japan Ozone data at Cruise Altitudes (7.7-11.3km) increased by 1ppb/year

  18. Other Tracers of Ozone

  19. Stratospheric Aerosol and NO2 Aerosol Sources : 1 Volcanic Activities (El Chichón and Mt.Pinatubo) 2 Some SO2 by Human-related activities But Stratospheric Aerosol remains near non-volcanic background • NO2 Sources : • Natural sources: Oxidation of ammonia in soils. • 2 Man-made source: Vehicular fuel combustion and industrial output. Short data records and hemispheric differences in trends are unexplained?? Figures from WMO 2006

  20. Political Scenario 1 WMO is a specialized agency of the United Nations (UN). 2 The results produce by WMO gives an overview of changing climate and making new governmental policies about climate change. http://www.wmo.ch/pages/about/index_en.html

  21. Total Ozone Column 1 Global mean of total column ozone values shows ozone is no longer decreasing. 2 Total column ozone in Southern Hemisphere (SH) and Northern Hemisphere (NH) mid-latitudes has recovered. 3 Seasonal differences in SH and NH are shown clearly. 4 Total column Ozone over tropics is unchanged. Vertical Ozone Distribution 1 Upper Stratosphere ------- no more Ozone decline. 2 Lower Stratosphere ---- ozone is constant with significant variability. 3 Troposphere --- Not a consistent trend. Summary Will it remain constant???

  22. Thank You For listening!!!!!!!!!!!! Comments!!!! Suggestions…………. www.google.com

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