Section 3 Remote sensing of global change Ozone hole Global Change Instructor: Dr. Cheng-Chien LiuCheng-Chien Liu Department of Earth Sciences National Cheng Kung University Office: Building of Earth Sciences, room Voice: ext Office hours: Monday 14:00 – 17:00, Wednesday 9:00 – 12:00 URL: Last updated: 22 April 2005

Compositions of atmosphere  Constituents N 2 O 2 Ar CO 2, H 2 O, Methane, O 3, SO 2, CFC, …  Distribution and structure Temperature Ozone

Fig. 1 Fig. 1 Vertical structure of ozone concentration and temperature in the atmosphere. Source:

Ozone  Origin O 2 + hυ→O + O O+ O 2 + M → O 3 + M  Unit Dobson unit ( DU ) 1 DU = Average O 3  300 DU = 0.3

Ozone (cont.)  Merits ozone  absorb UV radiation /moleculeC.movhttp://svs.gsfc.nasa.gov/vis/a000000/a001600/a /moleculeC.mov  Destruction CFC destruction  Ozone destruction /moleculeA.movhttp://svs.gsfc.nasa.gov/vis/a000000/a001600/a /moleculeA.mov /moleculeB.movhttp://svs.gsfc.nasa.gov/vis/a000000/a001600/a /moleculeB.mov

Ozone (cont.)  Consequences of losing ozone Different absorption of UV-A, UV-B, UV-C UV-C UV-B   Skin cancer, immune system, reptile eggs, photosynthesis, production, phytoplankton UV-A Biology > Climate

Fig. 2 The height to the ground that the solar radiation ranged from 140 to 340 nm can penetrate in the atmosphere. Source: Fig

Remote sensing techniques for studying ozone hole  Total Ozone Mapping Spectrometer

Remote sensing techniques for studying ozone hole (cont.)  Mission Nimbus-7 (1978/10 – 1993/5) Meteor-3 (1991/8 – 1994/11)  A short video of the Meteor-3 launch from the Plesetsk facility in Russia ADEOS (1996/7 – 1997/6) Earth Probe (1996/7 – present)

Remote sensing techniques for studying ozone hole (cont.)  Principle d/sbuv/oz_meas.htmlhttp://code916.gsfc.nasa.gov/Public/Space_base d/sbuv/oz_meas.html 12 bands from 255 nm to 340 nm  Penetrate to the ground  total column ozone  nm, nm, nm and nm  Take two band ratio (weakly and strongly absorbed)  Not penetrate to the ground  ozone vertical profile  255 – 306 nm   penetration   Wavelengths scan  attitude scan

Remote sensing techniques for studying ozone hole (cont.)  Measurements The evolution of the ozone hole over Antarctica (1979 – 1999) made by Nimbus-7 + Meteor-3 and Earth Probe  10.mpg 10.mpg Ozone in the northern and southern hemispheres as measured by Earth Probe TOMS from 7/26/1996 to 11/4/2001  84.mpg 84.mpg

Fig 3 Fig. 3 Earth Probe TOMS Total Ozone September 16, 2000 Source:

Fig 4 Fig. 4 Ozone hole size. Source: 01_bw.jpghttp://edc.usgs.gov/products/satellite/avhrr.html 01_bw.jpg

Questions  Why the ozone hole is only found in Antarctica?