Section 3 Remote sensing of global change

1. Section 3 Remote sensing of global change Ozone hole Global Change Instructor: Dr. Cheng-Chien Liu Department of Earth Sciences National Cheng Kung University Office: Building of Earth Sciences, room 30206 Voice: +886-6-2757575 ext. 65422 E-mail: ccliu88@mail.ncku.edu.tw Office hours: Monday 14:00 – 17:00, Wednesday 9:00 – 12:00 URL: http://mail.ncku.edu.tw./~ccliu88/ Last updated: 22 April 2005

2. Compositions of atmosphere • Constituents • N2 • O2 • Ar • CO2, H2O, Methane, O3, SO2, CFC, … • Distribution and structure • Temperature • Ozone

3. Fig. 1 Fig. 1 Vertical structure of ozone concentration and temperature in the atmosphere. Source: http://140.115.123.30/gis/globalc/fig/05-01.gif

4. Ozone • Origin • O2+ hυ→O + O • O+ O2+ M → O3 + M • Unit • Dobson unit ( DU ) • 1 DU = 10-5m @1atm • Average O3 300 DU = 0.3 cm @1atm

5. Ozone (cont.) • Merits • ozone  absorb UV radiation • http://svs.gsfc.nasa.gov/vis/a000000/a001600/a001603/moleculeC.mov • Destruction • CFC destruction  Ozone destruction • http://svs.gsfc.nasa.gov/vis/a000000/a001600/a001603/moleculeA.mov • http://svs.gsfc.nasa.gov/vis/a000000/a001600/a001603/moleculeB.mov

6. 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

7. Fig. 2.2.1 Fig. 2 The height to the ground that the solar radiation ranged from 140 to 340 nm can penetrate in the atmosphere.Source: http://140.115.123.30/gis/globalc/fig/05-10.gif

8. Remote sensing techniques for studying ozone hole • Total Ozone Mapping Spectrometer • http://toms.gsfc.nasa.gov/

9. 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 Russiahttp://toms.gsfc.nasa.gov/m3toms/images/m3launch2.mpg • ADEOS(1996/7 – 1997/6) • Earth Probe (1996/7 – present)

10. Remote sensing techniques for studying ozone hole (cont.) • Principle • http://code916.gsfc.nasa.gov/Public/Space_based/sbuv/oz_meas.html • 12 bands from 255 nm to 340 nm • Penetrate to the ground  total column ozone • 312.5 nm, 317.5 nm, 331.2 nm and 339.8 nm • Take two band ratio (weakly and strongly absorbed) • Not penetrate to the ground  ozone vertical profile • 255 – 306 nm • l penetration  • Wavelengths scan  attitude scan

11. 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 • http://svs.gsfc.nasa.gov/vis/a000000/a000700/a000710/a000710.mpg • Ozone in the northern and southern hemispheres as measured by Earth Probe TOMS from 7/26/1996 to 11/4/2001 • http://svs.gsfc.nasa.gov/vis/a000000/a002200/a002284/a002284.mpg

12. Fig 3 Fig. 3 Earth Probe TOMS Total Ozone September 16, 2000Source: http://toms.gsfc.nasa.gov/multi/recent_ozone91200.gif

13. Fig 4 Fig. 4 Ozone hole size. Source: http://www.gsfc.nasa.gov/gsfc/earth/pictures/20020926ozonehole/avg_size_o3hole79-01_bw.jpghttp://edc.usgs.gov/products/satellite/avhrr.html

14. Questions • Why the ozone hole is only found in Antarctica?