Lecture 20: Atmosphere Part 2 Flashcards
-Water Vapour and Cloud Formation -Cloud Types and Classification -How Incoming Radiation Drives Weather and Climate
What is Dalton’s law of partial pressures?
The pressure of a mixture of gases can be expressed as the sum of partial pressures of all the components.
What is partial pressure?
The amount of water vapor.
When is the air saturated?
When the rate of evaporation and condensation are balanced.
What is the saturation pressure?
The partial pressure of water at saturation.
What is relative humidity?
It is the partial pressure of water divided by the saturation pressure.
What is a adiabatic lapse rate?
The rate at which atmospheric temperature decreases with increasing altitude in conditions of thermal equilibrium.
What is nucleation energy?
The energy input that the first nucleus of a new water drop or ice crystal requires.
What makes nucleation easier?
If a solid surface is available (blade of grass or particle in the atmosphere).
How does density lifting happen?
It occurs because warm, lower density air rises and expands.
How does frontal lifting happen?
It occurs when the movement of air masses drives warm air over cold air.
What is a warm front?
A type of frontal lifting where warm air rises over cold air.
What is a cold front?
A type of frontal lifting where cold air is forced under warm air.
How does orographic lifting happen?
It occurs where mountain ranges force air masses to rise.
How does convergence lifting happen?
It occurs where masses of air collide, forcing them to rise.
What are the three major cloud types?
- Cumulus
- Stratus
- Cirrus
What are cumulus clouds?
Clouds that have a flat base and a dome top that is typical of rising warm air.
They generally form at lower altitudes.
What are stratus clouds?
Clouds that form horizontally extensive flat layers, and are typical of frontal lifting where warm air spreads over cold air.
They generally form at lower altitudes.
What are cirrus clouds?
Cloud that are wispy.
They generally form at high altitudes.
What are cumulonimbus clouds?
Cumulus -> heap and nimbus -> rain cloud
Are associated with heavy rain and lightning.
What are nimbostratus clouds?
Stratus -> flattened
Theses are stratus clouds that cover the entire sky and are associated with steady rain or snow.
What are stratocumulus clouds?
Occurs when cumulus clouds merge to form a semi-continuous layer in the atmosphere, with little or no precipitation.
What is energy flux?
Amount of energy in an electromagnetic wave that passes perpendicular through unit surface area per unit time (W/m^2).
What three things work together to pace long-term, natural, climate change
- Tilt
- Precession
- Eccentricity
