Global Atmospheric Change

Question 0

Ozone formation in stratosphere

Answer 0

• occurs continuously

* oxygen & sunlight

Question 1

2 major global scale environmental issues of international concern

Answer 1

1) global stratospheric ozone reduction

2) global climate change

Question 2

Ozone depletion in stratosphere

Answer 2

*release of source gases
-halocarbons (chlorofluorocarbons [CFCs], halons)
-natural sources (methyl chloride CH3Cl, methyl bromide
CH3Br)
*source gases are ultimately converted by UV radiation to reactive halogen gases, which destroy ozone

Question 3

The Antarctic Ozone Hole

Answer 3

Ozone hole forms because of the cold temperature of the Antarctic stratosphere

Question 4

Antarctic Ozone Hole results in…

Answer 4

The formation of polar stratospheric clouds (PSC) aka ice clouds

Question 5

Polar stratospheric clouds do what?

Answer 5

1) Convert inactive forms of chlorine (HCl & ClONO2) to chlorine gases
2) when sunlight becomes available (September, spring) the chlorine gas is converted to a reactive form of chlorine, which destroys ozone
3) causes seasonal ozone depletion

Question 6

Arctic depletion?

Answer 6

Depletion occurs but less severe, no large/ recurrent ozone hole

Question 7

Why is depletion less severe in the Arctic?

Answer 7

The arctic stratospheric winter is generally warmer which reduces the likelihood of PSC formation

Question 8

Trophospheric O3

Answer 8

Criteria pollutant

Question 9

Stratospheric O3

Answer 9

Ozone layer

Question 10

Climate change drivers (3) and what they may be affected by

Answer 10

1) changing the incoming solar radiation
- changes in Earth’s orbit
- changes in the Sun
2) altering the long wave radiation radiated back to space
- changes in greenhouse gases
3) changing the fractions of solar radiation that is reflected (albedo)
- changes in cloud covers
- changes in aerosols

Question 11

Orbital variations

Answer 11

Milankovitch cycles

1) eccentricity 
2) obliquity 
3) precession

Question 12

Eccentricity

Answer 12

The extent to which the Earth’s orbit around the Sun departs from a perfect circle

Question 13

Obliquity

Answer 13

Refers to the Earth’s tilt angle with respect to its orbit

Question 14

Precession

Answer 14

Changes in the precession of the Earth’s axis

*earth does NOT have a perfect spin around its axis, but it wobbles

Question 15

Greenhouse gases

Answer 15

• absorb radiation of longer wavelengths radiated by the Earth, resulting in a warming of the Earth’s surface
• CO2, CH4, N2O, O3, halocarbons

Question 16

Aerosols

Answer 16

• sulfate reflects incoming radiation- direct- cooling
• cloud condensation nuclei- indirect - cooling
• soot increases in absorption of radiation- direct- warming