Atmosphere Flashcards
1
Q
Earth’s axis of rotation and the plane of ecliptic are…
A
parallel
2
Q
axial tilt
A
angle of Earth’s axis of rotation
- relative to the normal to the orbital plane
- 23.4 degrees
3
Q
obliquity (of tilt)
A
- change in axial tilt
- 22 to 24.5 degrees
- period of 41 000 years
4
Q
axial precission
A
wobbling caused by gravitational attraction
- gravitational attraction from Sun and Moon
- period of 100 000 years
5
Q
Aphelion
A
- furthest from the sun (Summer in NH)
- July 4
6
Q
Periphelion
A
- closest to sun (Winter NH)
- Jan 4
7
Q
Earth’s Oscillation Period and Shape
A
- oscillates between circle and ellipse
- period of 100 000 years
8
Q
Earth’s Atmosphere Size
A
480 km
9
Q
Atmosphere Formation
A
- planet cooled at surface
- dense material went to the center
- lighter materials flowed to top -> created layers
- gases from inside out gassed the atmosphere (volcanic eruptions and collisions)
10
Q
Volcanic Outgassing
A
- lots of water (50-60%)
- quarter CO2 (24%)
- sulfur, 13% etc.
11
Q
Formation of the Ozone
A
- O2 is produced, UV radiation splits to create ozone (O3)
- ozone layer also created (UV shield)
12
Q
Main Reason for Seasons:
A
tilt!!
13
Q
Modern Atmosphere Composition
A
-70% N2
-21% Oxygen
-Ar 1%
-CO2 0.04%
….
14
Q
Thermosphere
A
- 80 - 550 km
- N, O, and smaller particles in Ionosphere absorb radiation from the sun
- become electrically charged
- absorbs cosmic rays (gamma, x, shorter)
- gases are layered by weight (gravity)
15
Q
Lower layers of Thermosphere
A
- 0-80 km
- chemically uniform mix of gases
- absorbs UV rays
- H20y variations near surface
16
Q
Density of Atmosphere
A
- density and pressure DECREASES with altitude
- troposphere contains 90% of mass
- above 50 km. 0.001% of mass
17
Q
Heterosphere (80-?)
A
- 80 km to 500 km
- 0.001% of mass
- distinct layers of gas due to gravity
18
Q
Homosphere
A
- 0 km to 80 km
- uniformly mixed
- ozone layer
19
Q
Thermosphere (temperature)
A
- 80 km to 480 km (thermopause)
- temperature INCREASES with altitude
- no heat conduction, high energy solar radiation
20
Q
Mesosphere (temperature)
A
- 50 km to 80 km
- temperature DECREASES with altitude (-90 C)
21
Q
Stratosphere (temperature)
A
- 18 km to 50 km
- temperature INCREASES with altitude
- from -57 C to 0 C at stratopause
- absorption of UV by ozone
22
Q
Troposphere (temperature)
A
- surface to 18 km
- decreases with altitude
- normal lapse rate of 6.5 degrees C /km
