21/11/20071 Global Ozone: Past and Present Abhinand Jha PEP Universität Bremen Presented for Presentation Tech. Course

21/11/20072 Overview 1 Motivation 2 General Introduction 3 Ozone Change Updates 4 Other tracers of O 3 5 Political Scenario 6 Summary

21/11/20073 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

21/11/2007Figures from WMO General Introduction

21/11/20075 Total Ozone columnVertical Ozone column General Idea

21/11/20076 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

21/11/20077 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.

21/11/20078 Ozone change updates

21/11/2007Figures from WMO Updated Results Ozone variations for 60 o S to 60 o N due to different atmospheric processes Elchichon and Mt.Pinatubo Linear Trend Scaled and fitted EESC(Eq.Eff.Stratospheric Chlorine) with ozone column O3 changes can be expressed In terms of EESC, Differences between time periods of EESC

21/11/ 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 O 3 ) !! Problem : Polar EESC is not included

21/11/2007Figures from WMO Total Ozone Changes 1 Satellite data from Total Ozone mapping Spectrometer (TOMS) 2 Solar backscatter ultraviolet (SBUV) Annual Avarages

21/11/2007Figures from WMO Ozone Changes in Tropics 1 Maximum ozone in tropics(40%). 2 Small changes but not statistically significant Ozone column is unchanged at the equator

21/11/2007Figures from WMO Seasonal Ozone variations Ozone Minimum due to volcanic eruptions(Mt.Pinatubo) Low due to regular spring time ozone deplition Clear Difference between NH and SH mid-latitudes.

21/11/2007Figures from WMO Vertical Distribution of Ozone 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) 1 Upper Stratosphere Long term decline of ozone till 1996 but then the trend seem to be constant

21/11/2007Figures from WMO Lower Stratosphere Ozone reached minimum values till 1993 but now they are again recovering to the values of early 1980‘s

21/11/2007Figures from WMO Latitudinal Ozone Profiles Tropical differences ….????? Vertically integrated SAGE I+II data,compared with results from the merged TOMS/SBUV column ozone dataset.

21/11/ Tropospheric Ozone (TO) 1 Changes in TO are regional 2 The trends within the region changed over last years Increase of TO over Canada and decrease over Europe and Japan 43%±25%/decade increase of TO over Delhi Ozone data at Cruise Altitudes ( km) increased by 1ppb/year

21/11/ Other Tracers of Ozone

21/11/2007Figures from WMO Stratospheric Aerosol and NO 2 Aerosol Sources : 1 Volcanic Activities (El Chichón and Mt.Pinatubo) 2 Some SO 2 by Human-related activities NO 2 Sources : 1Natural sources: Oxidation of ammonia in soils. 2 Man-made source: Vehicular fuel combustion and industrial output. But Stratospheric Aerosol remains near non-volcanic background Short data records and hemispheric differences in trends are unexplained??

21/11/ 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. _en.html

21/11/ Summary 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. Will it remain constant???

21/11/ Thank You For listening !!!!!!!!!!!! Comments!!!! Suggestions………….