Atmospheric Chemistry 1
This document was uploaded by user and they confirmed that they have the permission to share it. If you are author or own the copyright of this book, please report to us by using this DMCA report form. Report DMCA
Overview
Download & View Atmospheric Chemistry 1 as PDF for free.
More details
- Words: 844
- Pages: 64
“Stratospheric Ozone Depletion by Chlorofluorocarbons” U.C.I.-NASA July 14, 2009 Prof. F. Sherwood Rowland University of California, Irvine, CA
Gay-Lussac & Biot Paris, 1804 N2/O2 = 4
GREENHOUSE GASES
Dobson
Götz
Chapman
International Ozone Conference, Oxford, U.K., 1936
Stratospheric O3 Formation The “Chapman Reactions”, (oxygen-only, 1930) O2 + hν → O + O
(1)
O + O 2 + M → O3 + M
(2)
O3 + hν → O + O2 O + O3 →
O2 + O2
(Sunlight)
(3) (4)
One D.U. ~ 10-9 USSR
Global average ozone about
Australia
300
Switzerland
Peru
Seasonal & Latitudinal Variations of Atmospheric Ozone (Dobson, 1968)
F. S. Rowland, Lecture Notes, Fort Lauderdale Florida Feb. 1972
1973
UCI Laboratory, F. S. R., with Mario Molina, People Magazine, October 1976
Free Radicals Odd number of electrons Hydrogen Nitrogen
H (1), HO (9), HO2 NO (15), NO2
Halogen Cl (17), ClO (25), Br, BrO ODD PLUS EVEN ALWAYS GIVES ODD
Mario J. Molina & F. S. Rowland Department of Chemistry, University of California, Irvine, California 92664
Chlorofluoromethanes are being added to the environment in steadily increasing amounts. These compounds are chemically inert and may remain in the atmosphere for 40-150 years, and concentrations can be expected to reach 10 to 30 times present levels. Photodissociation of the chlorofluoromethanes in the stratosphere produces significant amounts of chlorine atoms, and leads to the destruction of atmospheric ozone. Nature, June 28, 1974
CHLORINE ATOM PRODUCTION RATE CM-3 SEC-1
50
10
ALTITUDE
ATMOSPHERES -.001
20
40 KM
B,C -.01
A
30
20
0.1
10 1972 0
LIFETIMES TROPOPAUSE A 41 YEARS A B 42 YEARS C 52 YEARS
C
B
1.0 0
200
400 CCl3F
600
800 PPTV
Calculated vertical profile for CCl3F, 30° N Rowland & Molina, Rev. Geophys. Space Phys., 1975
NAS Reports September 1976 (scheduled for April)
Formation of Chlorine Nitrate in the Atmosphere
ClO + NO2 + M → ClONO2 + M
Others = HCl, HOCl, HONO2, HOONO, H2O2, ClOOCl, etc.,
September 13, 1976, Los Angeles Times
British Antarctic Survey Base, Halley Bay, Antarctica, 75.5° S
New York Times September 19, 1987
White spaces = no data
HCl + ClONO2 → Cl2 + HNO3 H. SATO & F. S. ROWLAND
Add HCl
HNO3
05/15/84
17:43:09
05/15/84
17:43:10
05/15/84
17:43:11
05/15/84
17:43:12
ClONO2
(a) (b) (c)
0
(a) 4.2%
CONNELL AND WUEBBLES,1984
∆O3 %
-10 (a) STANDARD CASE -20
(b) H2O (c) HCl
1950 1960 1970 1980 DATE
(b) 24.0%
0
100 200
400 FUTURE YEARS (c) 31.7% FROM (1983)
H2O + ClONO2 → HOCl + HNO3 HCl + ClONO2 → Cl2 + HNO3
Antarctic ClO in 1986
(deZafra & P. Solomon 1987)
50
Altitude (Km)
40 30 20 10 0.0
0.5
{
O + O3 → 2O2
2O3 → 3O2
1.0
{
1.5
2.0 Mixing Ratio (ppb)
Cl + O3 → ClO + O2 ClO + O → Cl + O2
2[Cl + O3 → ClO + O2] 2ClO →ClOOCl ClOOCl + hν → Cl + ClO → 2Cl + O
Mid-winter, 28 July 1999 – 255 DU 29 September 1999 – Total Ozone – 90 DU -- Temperature
PSCs
PERCENT DIFFERENCE
% TOTAL OZONE CHANGE WINTER (DJFM) (1976 – 1986) MINUS (1965 – 1975)
NORTH LATITUDE
% OZONE CHANGES VERSUS LATITUDE (1970 – 1986) MINUS (1969 & EARLIER) Harris and Rowland, 1988
June, 1989
100
USHUAIA, ARGENTINA (55°S) AUSTRAL SPRING 1991
10.0
1.0
TOMS OZONE 189
0.10 TOMS OZONE 355 OCT. 20 OCT. 21 OCT. 23 NOV. 6
0.010
0.0010 290
295
300
305
310
UV WAVELENGTH, NANOMETERS Surface UV-B intensities on 4 different days
BIOSPHERIC INSTRUMENTS, INC.
October 4, 2004
Total Ozone (Dobson Units) 110
220
330
440
550
26.9
N O D A T A
27.1
27.4
2007, 200 about lik 2004/2005
CFC-11 (ppt)
280
270 260
1996
2000
2004
Concentration of CCl3F (CFC-11) vs. time. Units parts per 1012 . Northern Hemisphere (blue), Global (green), Southern Hemisphere (red). Dutton et al., NOAA/CMDL
CFC-12 (ppt)
530 520 510 500 1996
2000
2004
Concentration of CCl2F2 (CFC-12) vs. time. Units parts per 1012 . Northern Hemisphere (blue), Global (green), Southern Hemisphere (red).
Ozone Hole October 8, 2005 Punta Arenas 156 D.U. Ushuaia 161 D.U.
Halley Bay 113 D.U.
Total Ozone (Dobson Units) 110
220
330
440
550
April 2, 2007 Supreme Court Decision, Majority Opinion, J. P. Stevens (1) A well-documented rise in global temperatures (2) a significant increase in the concentration of carbon dioxide in the atmosphere. (3) respected scientists believe the two trends are related.
_1.0
_0.5
_0.0
Increasing concentrations of atmospheric carbon dioxide 388.5, May 2008 Keeling and Whorf, 2005
Mauna Loa, Hawaii
(Red)
When is Inadvertent Geoengineering of the Atmosphere no longer “inadvertent”?
Watts per square meter Cooling warming
IPCC
albedo
Watts per square meter cooling warming
IPCC
HCFC-22 CHClF2 PRODUCTION FLUORINATION OF CHLOROFORM CHCl3
→ CHCl2F HCFC-21
kHO (In units of 10
-16
820
1.7
→ CHClF2
→ CHF3
HCFC-22 35
HFC-23 1.7
cm3
molecule-1 sec-1 at 7 C) Atmospheric
0.41
1.7
12
270
--
151
1810
14,760
Lifetime, years 100-year GWP (WMO-50, 2007)
IMOS Report June 1975
White House, 1997
July
Gay-Lussac & Biot Paris, 1804 N2/O2 = 4
GREENHOUSE GASES
Dobson
Götz
Chapman
International Ozone Conference, Oxford, U.K., 1936
Stratospheric O3 Formation The “Chapman Reactions”, (oxygen-only, 1930) O2 + hν → O + O
(1)
O + O 2 + M → O3 + M
(2)
O3 + hν → O + O2 O + O3 →
O2 + O2
(Sunlight)
(3) (4)
One D.U. ~ 10-9 USSR
Global average ozone about
Australia
300
Switzerland
Peru
Seasonal & Latitudinal Variations of Atmospheric Ozone (Dobson, 1968)
F. S. Rowland, Lecture Notes, Fort Lauderdale Florida Feb. 1972
1973
UCI Laboratory, F. S. R., with Mario Molina, People Magazine, October 1976
Free Radicals Odd number of electrons Hydrogen Nitrogen
H (1), HO (9), HO2 NO (15), NO2
Halogen Cl (17), ClO (25), Br, BrO ODD PLUS EVEN ALWAYS GIVES ODD
Mario J. Molina & F. S. Rowland Department of Chemistry, University of California, Irvine, California 92664
Chlorofluoromethanes are being added to the environment in steadily increasing amounts. These compounds are chemically inert and may remain in the atmosphere for 40-150 years, and concentrations can be expected to reach 10 to 30 times present levels. Photodissociation of the chlorofluoromethanes in the stratosphere produces significant amounts of chlorine atoms, and leads to the destruction of atmospheric ozone. Nature, June 28, 1974
CHLORINE ATOM PRODUCTION RATE CM-3 SEC-1
50
10
ALTITUDE
ATMOSPHERES -.001
20
40 KM
B,C -.01
A
30
20
0.1
10 1972 0
LIFETIMES TROPOPAUSE A 41 YEARS A B 42 YEARS C 52 YEARS
C
B
1.0 0
200
400 CCl3F
600
800 PPTV
Calculated vertical profile for CCl3F, 30° N Rowland & Molina, Rev. Geophys. Space Phys., 1975
NAS Reports September 1976 (scheduled for April)
Formation of Chlorine Nitrate in the Atmosphere
ClO + NO2 + M → ClONO2 + M
Others = HCl, HOCl, HONO2, HOONO, H2O2, ClOOCl, etc.,
September 13, 1976, Los Angeles Times
British Antarctic Survey Base, Halley Bay, Antarctica, 75.5° S
New York Times September 19, 1987
White spaces = no data
HCl + ClONO2 → Cl2 + HNO3 H. SATO & F. S. ROWLAND
Add HCl
HNO3
05/15/84
17:43:09
05/15/84
17:43:10
05/15/84
17:43:11
05/15/84
17:43:12
ClONO2
(a) (b) (c)
0
(a) 4.2%
CONNELL AND WUEBBLES,1984
∆O3 %
-10 (a) STANDARD CASE -20
(b) H2O (c) HCl
1950 1960 1970 1980 DATE
(b) 24.0%
0
100 200
400 FUTURE YEARS (c) 31.7% FROM (1983)
H2O + ClONO2 → HOCl + HNO3 HCl + ClONO2 → Cl2 + HNO3
Antarctic ClO in 1986
(deZafra & P. Solomon 1987)
50
Altitude (Km)
40 30 20 10 0.0
0.5
{
O + O3 → 2O2
2O3 → 3O2
1.0
{
1.5
2.0 Mixing Ratio (ppb)
Cl + O3 → ClO + O2 ClO + O → Cl + O2
2[Cl + O3 → ClO + O2] 2ClO →ClOOCl ClOOCl + hν → Cl + ClO → 2Cl + O
Mid-winter, 28 July 1999 – 255 DU 29 September 1999 – Total Ozone – 90 DU -- Temperature
PSCs
PERCENT DIFFERENCE
% TOTAL OZONE CHANGE WINTER (DJFM) (1976 – 1986) MINUS (1965 – 1975)
NORTH LATITUDE
% OZONE CHANGES VERSUS LATITUDE (1970 – 1986) MINUS (1969 & EARLIER) Harris and Rowland, 1988
June, 1989
100
USHUAIA, ARGENTINA (55°S) AUSTRAL SPRING 1991
10.0
1.0
TOMS OZONE 189
0.10 TOMS OZONE 355 OCT. 20 OCT. 21 OCT. 23 NOV. 6
0.010
0.0010 290
295
300
305
310
UV WAVELENGTH, NANOMETERS Surface UV-B intensities on 4 different days
BIOSPHERIC INSTRUMENTS, INC.
October 4, 2004
Total Ozone (Dobson Units) 110
220
330
440
550
26.9
N O D A T A
27.1
27.4
2007, 200 about lik 2004/2005
CFC-11 (ppt)
280
270 260
1996
2000
2004
Concentration of CCl3F (CFC-11) vs. time. Units parts per 1012 . Northern Hemisphere (blue), Global (green), Southern Hemisphere (red). Dutton et al., NOAA/CMDL
CFC-12 (ppt)
530 520 510 500 1996
2000
2004
Concentration of CCl2F2 (CFC-12) vs. time. Units parts per 1012 . Northern Hemisphere (blue), Global (green), Southern Hemisphere (red).
Ozone Hole October 8, 2005 Punta Arenas 156 D.U. Ushuaia 161 D.U.
Halley Bay 113 D.U.
Total Ozone (Dobson Units) 110
220
330
440
550
April 2, 2007 Supreme Court Decision, Majority Opinion, J. P. Stevens (1) A well-documented rise in global temperatures (2) a significant increase in the concentration of carbon dioxide in the atmosphere. (3) respected scientists believe the two trends are related.
_1.0
_0.5
_0.0
Increasing concentrations of atmospheric carbon dioxide 388.5, May 2008 Keeling and Whorf, 2005
Mauna Loa, Hawaii
(Red)
When is Inadvertent Geoengineering of the Atmosphere no longer “inadvertent”?
Watts per square meter Cooling warming
IPCC
albedo
Watts per square meter cooling warming
IPCC
HCFC-22 CHClF2 PRODUCTION FLUORINATION OF CHLOROFORM CHCl3
→ CHCl2F HCFC-21
kHO (In units of 10
-16
820
1.7
→ CHClF2
→ CHF3
HCFC-22 35
HFC-23 1.7
cm3
molecule-1 sec-1 at 7 C) Atmospheric
0.41
1.7
12
270
--
151
1810
14,760
Lifetime, years 100-year GWP (WMO-50, 2007)
IMOS Report June 1975
White House, 1997
July
Related Documents
Atmospheric Chemistry 1
May 2020 5
Atmospheric Sciences_001
November 2019 17
Atmospheric Stuffs
November 2019 16
Atmospheric Pressure
May 2020 12
Chemistry 1
December 2019 7
Atmospheric Temperature
November 2019 13More Documents from ""
Modeling 2
May 2020 4
The Dc-8 Data System: David Van Gilst Nserc
May 2020 4
Atmospheric Chemistry 1
May 2020 5
