Earth Science Test 2 Flashcards
(37 cards)
Force per unit area that one object exerts on another
Pressure
A measure of the amount of force per area, that a gas exerts against containing wall
GP
What percent in Nitrogen in the Earth’s Atmosphere?
78%
What percent of Oxygen is in the Earth’s atmosphere?
21%
What are the layers of the atmosphere?
Troposphere, Stratosphere, Mesosphere, Thermosphere, Ionosphere, and Exosphere.
Lowest and Thinnest layer, 90% of atmosphere’s mass, where weather occurs, temp decreases w/altitude, Top of it averages -50 C
Troposphere
Top of troposhere to 50km above surface, ozone layer absorbs harmful UV radiation, temp increases because of ozone absorption of UV radiation
Stratosphere
JUST GETS COLDER
Mesosphere
Temp increases w. altitude (temp is related to average speed of gas molecules, very high speed gives higher temps, temps up to 1500C), very low density of gas molecules means very little heat absorption-it would feel cold, feels this way bc of very little gas molecules
Thermosphere
SPACE!!! Gradual (gets colder due to being further from heat source (Earth), ozone picks up UV light (absorbs it)
Exosphere
Solar intensity is _________ where the sun’s rays strike Earth’s surface _______
Highest, Straight on
Solar Intensity is __________ where sun’s rays strike Earth’s surface at an ________
weaker, angle
Greenhouse Gas Effect
Human activities pump greenhouse gases into the atmosphere: carbon dioxide, methane, nitrous oxide, ozone, CFCs.
The result is a warming Earth.
Why do we have seasons?
Variation in solar intensity with latitude and the tilt of the Earth’s axis helps to explain the different seasons.
When the Sun’s rays are closest to perpendicular at any spot on the Earth, that region’s season is summer.
Six months later, as the rays fall upon the same region more obliquely, the season is winter.
In between are the seasons fall and spring.
Force atmosphere exerts on a surface (at any level in the atmosphere, force = total weight of air above that level, at higher elevations, w/fewer air molecules, pressure is less)
Atmospheric Pressure
Convection Cycle:
- Warm air parcel rises; Cooler air parcel sinks
- Warm air is less dense than cool air
Convection currents stir the wind:
- Wind is air that flows horizontally from higher
pressure to lower pressure.
- The greater the pressure gradient, the
stronger the wind.
Pressure differences are caused by uneven heating of the Earth’s surface.
Local differences in heating contribute to small-scale local winds.
Planet-scale differences occur because of solar intensity variations—equatorial regions have greater solar intensity than polar regions.
Differences contribute to global wind patterns—prevailing winds.
Temp-Pressure Relationship
Warm air characteristics Temp Pressure Relateionship
Warm air expands
Warm air has lower density and lower pressure
Cool Air characteristics Temp pressure Relationship
Cool air contracts
Cool air has higher density and higher pressure
Pressure Gradient force
land to sea, sea to land
High-Low, Low-High Pressure
Air moves from high to low pressure
(THINK OF ONE FUN LAB)
Moving bodies (such as air) deflect to the right in the Northern Hemisphere, to the left in the Southern Hemisphere
The Coriolis Force
Northern Hemisphere gets deflected to the ______
Right
Southern Hemisphere gets deflected to the ______
Left
The pressure gradient force: air moves from high pressure to low pressure
The Coriolis force: apparent deflection of winds due to Earth’s rotation
Frictional force: air moving close to ground encounters friction
Factors that affect wind
STUDY WEATHER STATION SYMBOLS
DO IT
