# Study Guide: Atmospheric Thermodynamics and Atmospheric Physics

Topics: Water vapor, Energy, Precipitation Pages: 7 (1751 words) Published: February 9, 2014
﻿Lecture 1
Which gases are the primary constituents of the atmosphere
78% Nitrogen, 21% Oxygen, 1% Argon, .038% carbon dioxide, .002% Others What is the difference between weather and climate?
Weather= atmospheric conditions at a particular time & place. (Temp, pressure, humidity, cloud cover, etc) Climate= the average weather over a long period of time. (long-term weather data) What is the difference between satellites and radar?

Satellites view clouds from space
Radar view precipitation from the ground
Can sense motion of precipitation particles toward/away from radar How is wind direction defined?
The direction from which the wind is blowing (a north wind blows form the north, to the south) How do winds blow around high and low pressure systems in the Northern Hemisphere  and how does this influence the temperatures near these systems? Low pressure=counter-clockwise, clouds and rain, warmer temperatures, rising air High pressure= clockwise, clear skies, cooler temperatures, sinking air Air pressure moves from high to low

Cold and warm air meet at fronts
Fronts connect to low pressure centers
Lecture 2
What is pressure and how does it change with height?
The amount of air molecules in a given area.
The more molecules the more weight.
Greatest weight and pressure is at bottom. As you go up, there is less. Pressure decreases with height
Pressure=weight/area
Measured with barometers
What is the average atmospheric pressure (in mb) at sea level? 1013.25mb
What is density and how does it change with height?
Mass/volume
Always decreases with height
Why is pressure corrected to sea level?
Because pressure differs through elevation. About 300mb between sea level and high mountains. Must correct pressure to remove variability to get a clear picture of weather. What is a lapse rate?
The rate at which temperature decreases with height
What is an inversion?
Layer which temperature increases with height
What is the troposphere?
Lowest layer (8-12km) of the atmosphere.
Contains Earth’s weather.
Temperature usually decreases with height.
How is the atmosphere divided into layers? What are they?
We use temperature to divide the atmosphere into vertical layers Troposphere=temp decrease
Stratosphere= temp increase, ozone
Mesosphere= temp decrease,
Thermosphere= temp increase
Lecture 3
What is temperature?
The measure of the average speed of the molecules of a substance When the molecules of a substance absorb energy, they move faster How does temperature affect air density?
Warm air is less dense (rises)
Cold air is more dense (sinks)
What is sensible heat?
Heat that can be measured with a thermometer
What is latent heat?
The energy absorbed or released during a phase change (“hidden” energy) What are the phase changes of water? Which are warming and which are cooling  processes? Why? Liquid, Solid, Gas
Warming (absorb latent heat): Freezing, deposition (gas to solid), condensation (gas to liquid) Cooling (release latent heat): melting, sublimation (solid to gas), evaporation What is conduction? Convection? Advection?

Conduction= direct transfer of heat within a substance or from one substance to another. Flow from hot to cold. Good heat conductor=metals. Bad heat conductor= air, water Convection= Transfer of heat through fluid flow (air and water), vertical. Advection: Transfer of heat or moisture, horizontal

How does the sun heat the lower atmosphere?
The sun heats the surface. Thin layer of air just above surface is heated by conduction. Hot air expands and begins to rise How does the temperature of air change as it rises and sinks? Why? As hot air rises, the pressure around it decreases, so the air around it expands. Hot air rises, expands, and cools

Sinking air compresses and warms.
Lecture 4
All objects emit radiation at all times
How is the wavelength of electromagnetic radiation related to energy? Shorter...