DOC PREVIEW
CU-Boulder PHYS 3070 - OZONE LAYER

This preview shows page 1-2-21-22 out of 22 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 22 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 22 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 22 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 22 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 22 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

http://physics.colorado.edu/phys3070Ozone creationOzone creationOzone destructionDark reactionsVariation in ozoneAntarctic holeChloro-fluoro-carbons (CFC)Chlorine in the antarcticAntarctic Spring (October)Antarctic Spring (October)Ozone depletion at mid-latitudesSolutionsCurrent statusJudah Levine, 3070L37 1http://physics.colorado.edu/phys3070http://physics.colorado.edu/phys3070Judah LevineJudah LevineJILA SJILA [email protected]@colorado.edu303 492303 492--7785 (27785 (2--7785)7785)M,F 11M,F 11--Noon, W 1Noon, W 1--3 pm3 pmalso by appointmentalso by appointmentJudah Levine, 3070L37 2Ozone layer→Judah Levine, 3070L37 3Ozone creationOzone creationO2+ UV → O + O (1)O + O2→ O3(2)UV wavelenghth < 240 nmShorter than UVBCreation of Ozone absorbs UVJudah Levine, 3070L37 4Ozone creationOzone creationO2+ UV → O + O (1)O + O2→ O3(2)UV wavelenghth < 240 nmShorter than UVBCreation of Ozone absorbs UVReaction (1) increases with altitudeReaction (2) decreases with altitudeJudah Levine, 3070L37 5Ozone destructionOzone destructionO3+ UV → O2+ O (1)O + O3→ O2+ O2(2)O3+ O3→ 3O2(very unlikely)Reaction (1) increases with altitudeNet effect of all reactions is to absorb UVand warm the stratosphereChapman reactions – Chapman layerJudah Levine, 3070L37 6Dark reactionsDark reactionsO + O3→ O2+ O2(2)O + O2→ O3(2)Free oxygen atoms disappearO2and O3come to equilibriumJudah Levine, 3070L37 7Variation in ozoneVariation in ozone24-hour day/night variationAnnual variationLatitude variationLong period pseudo-random variationsJudah Levine, 3070L37 8Ozone distribution:Thinnest in the tropicsNot what you thought←Dobson UnitsJudah Levine, 3070L37 9Judah Levine, 3070L37 10Judah Levine, 3070L37 11Antarctic ozoneholeJudah Levine, 3070L37 12Antarctic holeAntarctic holeSouth PoleCold air flowPolarVortextrap-80CPolar stratosphericClouds. FrozenNitric Acid + waterNo landSouth ofAbout 50sJudah Levine, 3070L37 13ChloroChloro--fluorofluoro--carbonscarbons(CFC)(CFC)Methane: CH4Chlorine and Fluorine replace hydrogenFreon (50+ years)Carbon Tetrachloride (26 years)Chemically inertNot water soluble HlH–C–HlHJudah Levine, 3070L37 14Judah Levine, 3070L37 15Chlorine in the Chlorine in the antarcticantarcticChlorine is trapped in the polar vortex during the Southern winterCondenses on the polar stratospheric cloudsChlorine NitrateHydrochloric AcidJudah Levine, 3070L37 16Antarctic Spring (October)Antarctic Spring (October)Reservoir species + sunlight → free chlorineCatalytic cycle:Cl + O3→ ClO + O2(happens twice)ClO + ClO → Cl2O2Cl2O2+ UV → 2Cl + O2Judah Levine, 3070L37 17Antarctic Spring (October)Antarctic Spring (October)Reservoir species + sunlight → free chlorineCatalytic cycle:Cl + O3→ ClO + O2(happens twice)ClO + ClO → Cl2O2Cl2O2+ UV → 2Cl + O2Net effect: 2 ozone turned into 3 oxygen,Chlorine ready to go againJudah Levine, 3070L37 18Ozone depletion at midOzone depletion at mid--latitudeslatitudesAntarctic ozone hole depends on polar stratospheric cloudsto form free chlorineNorthern hemisphere not as cold during the winterDifferent dynamics at mid-latitudesJudah Levine, 3070L37 19Judah Levine, 3070L37 20Judah Levine, 3070L37 21SolutionsSolutionsQQMontreal Protocol, 1987Montreal Protocol, 1987––Reduce atmospheric chlorine by 50% by Reduce atmospheric chlorine by 50% by 20002000QQRevision in 1992Revision in 1992––Stop production of chlorine compounds by Stop production of chlorine compounds by 19951995Judah Levine, 3070L37 22Current statusCurrent statusQQDensity of CFC in the troposphere Density of CFC in the troposphere declining slowly from peak in 1992declining slowly from peak in 1992QQDensity of CFC in the stratosphere near Density of CFC in the stratosphere near peak valuepeak valueQQAntarctic ozone hole still increasingAntarctic ozone hole still increasing––will return to prewill return to pre--1980 values by 20501980 values by 2050QQComplicated interaction between Complicated interaction between climate change and ozoneclimate change and


View Full Document

CU-Boulder PHYS 3070 - OZONE LAYER

Documents in this Course
Lecture 9

Lecture 9

23 pages

Lecture 8

Lecture 8

19 pages

Lecture 7

Lecture 7

19 pages

Lecture 6

Lecture 6

15 pages

Lecture 5

Lecture 5

19 pages

Lecture 4

Lecture 4

24 pages

Lecture 3

Lecture 3

17 pages

Lecture 2

Lecture 2

21 pages

Questions

Questions

22 pages

Lecture

Lecture

5 pages

Load more
Download OZONE LAYER
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view OZONE LAYER and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view OZONE LAYER 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?