Intro pt. 1

Question 1

*

4 Major ‘spheres’

Answer 1

• lithosphere
• hydrosphere
• atmosphere
• biosphere

Question 2

envelope of gas that surrounds the Earth

Answer 2

atmosphere

Question 3

• boundary between ____ and space, not sharp
• but ________ km of Earth’s surface
• the bulk (99% by mass), in the lower _____ km

Answer 3

• Atmosphere
• 80, 000 km
• 50 km

Question 4

The atmosphere:
* acts as a ______, removing DNA-destroying high energy UV-radiation;

• traps infrared radiation, transforms it into ____________ → warming the surface
• forms a ____ through which life-sustaining energy and matter move

Answer 4

• filter
• Thermal motion
• conduit

Question 5

________, prior to life, formed from
outgassing from interior of the planet

• probably dominated by H2. He, small
  concentrations of NH3, H2O, CO2 and N2
• … more from volcanic eruptions, … also S

Answer 5

primitive atmosphere

Question 6

Irradiation of the _______ with UV light from the sun would have facilitated the reactions:

H2O + hv (λ<240 nm) → H + OH
CO2 + hv (λ<240 nm) → CO + O
(hv = photon of light; λ = wavelength)

The products of these reactions are _______.

Answer 6

prebiotic atmosphere
free radicals

Question 7

____ are chemical species containing unpaired electrons and are generally highly reactive.

Answer 7

Free radicals

Question 8

The atmosphere underwent a dramatic change with the evolution of _________.

Answer 8

photosynthetic organisms

Question 9

________ convert CO2 and H2O to carbohydrate and oxygen

Probably, the initial low concentration of O2 in the atmosphere made formation of life possible

Answer 9

photosynthetic organisms

Question 10

The ____that developed in oxygen-poor atmosphere (i.e., anaerobes) are forced to live in secluded environment (sediments, intestinal canals).

Answer 10

primitive organisms

Question 11

• Although, photosynthesis forms carbohydrates (plant biomass), not all these plant matter are recycled back to the atmosphere through ______ (oxidative decay, forming CO2).
• Some of these carbohydrates are effectively permanently removed, e..g. buried in the _____, forming part of the soil and in time fossil matter.

Answer 11

• respiration
• sediments

Question 12

• complex mixture of gases and suspended particles

Answer 12

Present Atmosphere

Question 13

Present atmosphere dominated by two gases:
* _____ and _______, which together account for 99% of the volume of dry air
* _____ + other gases of varying concentrations, normally considered as pollutants: 1%

Answer 13

• N2 (78 mol%) and O2 (21%)
• Argon

Question 14

The major components of dry air in the troposphere (lower 15 km)
* Nitrogen, N2
* Oxygen, O2
* Argon, Ar
* Carbon dioxide, CO2

Mol Percent? Mass Percent?

Answer 14

• Nitrogen, N2 - 78.09, 75.51
• Oxygen, O2 - 20.95, 23.15
• Argon, Ar - 0.93, 1.23
• Carbon dioxide, CO2 - 0.03, 0.05

Question 15

______ also contains trace gases, particulates and water.

Answer 15

Dry air

Question 16

Origin & Composition:
Several trace gases: CO, NOx, CFCs, SOx and CH4
* Atmospheric composition: ______

Answer 16

Relatively stable

Question 17

____(anthropogenic activities) is
removing the steady-state condition
* CH4, rising by about 1% annually?!

Answer 17

Human intervention

Question 18

_________
* very low density, low pressure
(< 10-5 atm)
* ______, formed when
high-energy short-wave solar
radiation (λ&laquo_space;200 nm) is
absorbed.

Answer 18

Thermosphere
* Atoms and ions

Question 19

Thermosphere
________; tend to recombine, release energy
* Energy →motion of molecules,
atoms or ions→warming of
thermosphere

Answer 19

Products are reactive

Question 20

The temperature of the thermosphere
decreases with decreasing altitude,
until the ______ is reached (about
90 km).

Answer 20

mesopause

Question 21

Thermosphere
Due to: the particles in the upper
thermosphere absorb the _______, which is responsible for the warming effect in the thermosphere.

Answer 21

short-wave radiation

Question 22

Below the mesopause (in the _________),the molecular species facilitates warming by the absorption of solar radiation (200 λ 300 nm).

Answer 22

mesosphere and stratosphere

Question 23

In _______:

At decreasing altitude, the population
(concentration) of the molecular species increases. → increasing T at decreasing altitude

Answer 23

mesosphere

Question 24

In _______:
But as altitude decreases, the amount of the radiation (200 λ 300 nm) decreases as it has been removed at higher altitudes. → decreasing T at decreasing altitude

Answer 24

Stratosphere

Question 25

there is a maximum temperature in the mesosphere-stratosphere region. →
_________.

Answer 25

stratopause

Question 26

Solar radiation energy→absorbed by
molecules→thermal motion→chemical reaction
* Ozone production

Where?

Answer 26

Stratosphere

Question 27

• UV light dissociates oxygen molecules to O atoms
• O2 atoms combine with another oxygen molecule (exothermic)

Answer 27

Formation of ozone

Question 28

The Stratosphere & Ozone:

Thus, there is a maximum O3
concentration at a certain
height.
(__ km at the poles, ___ km at the
equator)

Answer 28

15 km
30 km

Question 29

not a major constituent of any part of the atmosphere.

found only at trace levels at all altitudes.

Answer 29

Ozone

Question 30

the part of the stratosphere where ozone has its maximum concentration (8-10 ppm).

Answer 30

“Ozone layer”

Question 31

If all the ozone within the atmosphere were concentrated at sea level,
it would be only about _____ thick.

Answer 31

3 mm

Question 32

The ozone layer protects the Earth from much of the short-waved
_____.

Answer 32

radiation

Question 33

The radiation absorbed by the gases leads to _________by:
 absorption of solar UVC (< 280 nm) radiation by O2
 absorption by UVB (280 - 315 nm) and UVC radiation by O3
 Absorption of IR radiation from Earth by O3

Answer 33

localized heating

Question 34

creates an inversion that stabilizes against vertical air movement.

Answer 34

localized heating

Question 35

Troposphere
Contains about ____ of the mass of
the atmosphere
* _______ reactions among various
molecular species
* Key to many chemical processes:
____ and _____ radicals

Answer 35

• 90%
• Complex
• OH and NO3

Question 36

Troposphere
Nitrogen, oxygen and argon are not greenhouse gases!

Greenhouse gases: (4)
(methane)

Answer 36

H2O, CO2, CH4

Question 37

Troposphere
The concentration of these
greenhouse gases (which cause
warming) _______ as altitude
decreases → temperature ______ as altitude decreases

Answer 37

increases

Question 38

limits the flux of matter
from the troposphere to the
stratosphere.

Answer 38

Tropopause

Question 39

weather occurs at the ______

Answer 39

troposphere

Question 40

The higher layer: Thermosphere
* Temperature ____with increasing altitude
* UV radiation is absorbed by ______ molecules forming ions and electrons

Answer 40

• increases
• oxygen

Question 41

• Over the thermosphere, above 700 km:_________
• An increasing number of ionized particles form the _________.
• Atmosphere extends to a height of _____ km

Answer 41

Exosphere
Van Allen Belts
80,000 km

Question 42

The composition of the atmosphere is mainly constant, … result of _______ including
* Emissions
* Possible transformations
* Reactions with other compounds
* Eventual removal by deposition

which is ___ of substances in the atmosphere

Answer 42

global cycles
lifetime

Question 43

```

Reactive compounds → short lifetime
High emission, slow deposition, inert → long residence time, high concentration

Answer 43

Global Circulations

Question 44

Solid materials, … aerosols (so
small)…important as _______ in formation of clouds

Answer 44

condensation nuclei

Question 45

__________
* Water vapor, fluid (droplets, rain), solid (ice, snow)
* Part of the hydrological cycle
* Only ______ of the global water

Answer 45

Atmospheric Water
0.001%

Question 46

The dominant transport of water between the oceans and the land masses takes place via
the ______

Answer 46

atmosphere

Question 47

• concentration strongly varying (global average 4 vol. %)
• Concentration: often as relative humidity (actual vapor pressure/vapor pressure of water at saturation at the given temperature)

Answer 47

Water Vapor