Section 3 Remote sensing of global change Ozone

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: ccliu 88@mail. ncku. edu. tw Office hours: Monday 14: 00 – 17: 00, Wednesday 9: 00 – 12: 00 URL: http: //mail. ncku. edu. tw. /~ccliu 88/ 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 Vertical structure of ozone concentration and temperature in the atmosphere. Source: http: //140. 115. 123. 30/gis/globalc/fig/05 -01. gif

Ozone § Origin • O 2+ hυ→O + O • O+ O 2+ M → O 3 + M § Unit • Dobson unit ( DU ) • 1 DU = 10 -5 m @1 atm • Average O 3 300 DU = 0. 3 cm @1 atm

Ozone (cont. ) § Merits • ozone absorb UV radiation • http: //svs. gsfc. nasa. gov/vis/a 000000/a 001600/a 0 01603/molecule. C. mov § Destruction • CFC destruction Ozone destruction • http: //svs. gsfc. nasa. gov/vis/a 000000/a 001600/a 0 01603/molecule. A. mov • http: //svs. gsfc. nasa. gov/vis/a 000000/a 001600/a 0 01603/molecule. B. mov

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

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

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

Remote sensing techniques for studying ozone hole (cont. ) § Mission • Nimbus-7 (1978/10 – 1993/5) • Meteor-3 (1991/8 – 1994/11) v. A short video of the Meteor-3 launch from the Plesetsk facility in Russia http: //toms. gsfc. nasa. gov/m 3 toms/images/m 3 launch 2. mpg • ADEOS (1996/7 – 1997/6) • Earth Probe (1996/7 – present)

Remote sensing techniques for studying ozone hole (cont. ) § Principle • http: //code 916. gsfc. nasa. gov/Public/Space_base d/sbuv/oz_meas. html • 12 bands from 255 nm to 340 nm v. Penetrate to the ground total column ozone Ø 312. 5 nm, 317. 5 nm, 331. 2 nm and 339. 8 nm Ø Take two band ratio (weakly and strongly absorbed) v. Not penetrate to the ground ozone vertical profile Ø 255 – 306 nm Ø l penetration Ø 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 vhttp: //svs. gsfc. nasa. gov/vis/a 000000/a 000710/a 0007 10. mpg • Ozone in the northern and southern hemispheres as measured by Earth Probe TOMS from 7/26/1996 to 11/4/2001 vhttp: //svs. gsfc. nasa. gov/vis/a 000000/a 002284/a 0022 84. mpg

Fig 3 Fig. 3 Earth Probe TOMS Total Ozone September 16, 2000 Source: http: //toms. gsfc. nasa. gov/multi/recent_ozone 91200. gif

Fig 4 Fig. 4 Ozone hole size. Source: http: //www. gsfc. nasa. gov/gsfc/earth/pictures/20020926 ozonehole/avg_size_o 3 hole 7901_bw. jpghttp: //edc. usgs. gov/products/satellite/avhrr. html

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