Energy
The ability to do work, anything that changes the state of matter
Kinetic energy
All substances are composed of molecules/atoms that are in constant motion
Temperature
A description of the average kinetic energy of a substance
Heat
Energy that transfers from one object to another due to a difference in temperature
Solar energy
A type of electromagnetic radiation measured in mew
Ultraviolet
0.01 to 0.4 �
Visible Light
0.4 to 0.7 �
Infrared light
0.7 to 1000 �
Radiation
The process by which electromagnetic energy is radiated by something, the hotter it is the shorter the wave length
Absorption
When an object takes in electromagnetic energy that strikes it. This increases atomic motion (gets it warmer)
Reflection
The ability of an object to repel electromagnetic energy.
Scattering
Insolation is redirected by gas molecules or particles in the atmosphere
Rayleigh Scattering
Short wavelengths are scattered more than long wavelengths. Causes the sky to appear blue
Mie Scattering
Suspended particulate matter scatters all wavelengths equally. Causes the sky to appear gray
Transmission
The ability of electromagnetic energy to pass through a medium (Shorter wavelengths go through the atmosphere easier)
Green house effect
Average temperature of 5F without it
Conduction
Movement of heat energy from one molecule to another without a change in their positions
Convection
Heated molecules are transferred from one place to another through vertical circulation of a fluidic material. Air is heated an expands so it is less dense and rises and falls when it cools.
Advection
Heat transfer in a fluidic system that is primarily horizontal. In the atmosphere this is predominantly driven by wind.
Air pressure
Refers to the mass of the atmosphere being affected by gravity.
Adiabatic Heating and Cooling
Without the gain or loss of heat based on the expansion or compression of air
Latent heat
The physical state of water in the atmosphere undergoes change which cause energy to be stored or released.
Evaporation
Liquid water converts into water vapor, latent heat energy is stored and it cooling process
Condensation
Water vapor converts to liquid water, latent heat energy is released so it is a warming process
Angle of Incidence
The angle formed between the incoming rays of the sun and the surface of the Earth
Sensible heat
Can be detected with a thermometer, depends on temperature
Sublimate
Gas to solid or solid to gas water phase change
rising air (adiabatically)
cools
Descending air (adiabatically)
warms
incoming solar radiation
1) Reflected back to space by surface of earth or atmosphere
2) Absorbed by the atmosphere
3) Absorbed by the earth then reradiated the heat to the lower atmosphere with longer wave lengths and latent energy stored in water vapor
Earth's energy budget
Earth energy balance
A global balance is maintained by excess heat from the equator regions being transferred to the poles
Land and water contrasts
1) Heating: water has higher specific heat than land, water can absorb more solar energy than land without temp increase
2) Sun rays: penetrate deeper in water
3) Water is a good heat conductor and evaporation is greater over water (cooling effect of evap
Ocean circulation
Ocean water circulates in currents and surface currently are mostly caused by wind. The deep currently are driven by gravity.
Effects of ocean currents
1) Transfers heat to the poles
2) Influences weather
3) Distributes nutrients across the ocean
Ideal gas law
An increase in pressure produces a decrease in volume, an increase in pressure produces an increase in temperature
Dynamic High
Strongly descending air is associated with high pressure at the surface of the Earth
Dynamic Low
Strongly rising air is associated with low pressure at the surface of the Earth
Thermal High
Cold conditions are associated with high pressure at the surface of the Earth
Thermal Low
Warm conditions are associated with low pressure at the surface of the Earth
Station model
Station model abbreviation of air pressure
Remove the 9 or 10, and the decimal point
Normal pressure ranges
From 960 to 1050
Wind
Results from horizontal motion of air from areas of high surface pressure to areas of low surface pressure
Convection (air)
Air rises in warm regions where there is low pressure
Subsidence (air)
Air descends in cold areas where pressure is high
Wind circulation
Northern Hemisphere: low is counterclockwise, high is clockwise
Southern: Low is clockwise, high is counterclockwise
Friction and wind
High friction, slower wind
geostrophic winds
Winds high above surface friction
Jet Streams
Narrow bands of high velocity wind that form along the polar front and above the Hadley cell in the subtropics
Rosby waves
1) Zonal Flow: west to east pattern of wather movement
2) Meridional Flow: brings cold air to the equator and warm air to the poles
Sea and Land breezes
Common to tropical coastlines and midlatitude in the summer. Provides moisture for midafternoon thunderstorms and hold down temp in the early day.
Valley and mountain breezes
Mountain slopes heat up more during the day than the valley and opposite at night.
Katabatic winds
Winds originate in cold upland areas and move quickly over a drop off. Air cools on the plateau and warms as it descends.
Foehn Winds/Chinook
Driven by the pressure gradient, extreme change in temperature as it moves to warm
Santa Ana Winds
Develops when high pressure sits over the interior for extended amounts of time. Winds diverge clockwise out of the high bringing warm, dry air to the coast (creates fire conditions).
Teleconnections
Refers to climate anomalies related to each other over large distances
La nina
Pacific Decadal Oscillation
Long term pattern of sea surface temperatures between the northwest tropical and eastern tropical Pacific ocean.
North Atlantic Oscillation
Irregular variation in air pressure between the Icelandic low and the subtropical high that affects atmospheric circulation. In the positive phase pressure centers are enhanced while in the negative phase they are reduced.
El nino
El Ni�o occurs generally every 3 to 8 years and lasts 9 months to 2 years.
The Arctic Oscillation
Associated with the NAO, a NAO positive time is also the Arctic Oscillations warm phase.
During this warm phase the polar highs are not as strong so less cold polar air gets pushed to the south leading to warmer water temperatures. During the cold phase i
Polar molecule
Electrical negative will attract positive charge. The attraction makes water molecules want to join together
Adhesion (water)
Water likes to stick to many other substances
capillarity
Caused by surface tension and adhesion.
Hydrologic cycle
Surface Tension
Electrical Polarity causes the surface of liquid water to bead, hydrogen bonds are stronger than the bug's weight
Source of atmospheric water
Evaporation and transpiration.
Saturation
The equilibrium condition when the rate of evaporation is equal to the rate of condensation is called saturation
Air temperature and water
air can hold more water at higher temperatures
Mixing Ratio
The mixing ratio (w) is the mass of water vapor per mass of dry air, typically decreases with height (what we actually have).
Saturation Mixing Ratio
is the mass of water vapor per mass of dry air if the air is saturated at the current temperature (what we could have if we are saturated)
Vapor Pressure
The vapor pressure (e) is the pressure exerted by just the water vapor in the air
Saturation Vapor Pressure
The saturation vapor pressure (es) is the pressure exerted by the water vapor molecules when the air is saturated
Dew Point
After Saturation Occurs the Air Must Release Extra Water as Fluid. This temp. at which it releases water is called the dew point
Homogeneous nucleation
droplet formed only by water molecules at very cold temperatures (-40)
Heterogeneous nucleation
particle other than water serves as a site for cloud droplet formation
Relative Humidity
Equals (MR/SMR) x 100, ratio of the air's content to its capacity. Condensation occurs at 100%. Adding water vapor and/or cooling the air increases the relative humidity and vice versa.
Hygroscopic nuclei
water-attracting nuclei that can form cloud droplets at less than 100% RH (like salt)
Hydrophobic nuclei
resists water unless 100% RH (like clay)
Cloud classification
Based on Form and family
Cirriform (Cloud form)
Thin and wispy clouds at high altitude, composed of ice crystals not water
Stratiform (Cloud form)
Spread out, appears as grayish sheets and rarely broken into individual units
Cumuliform (Cloud form)
Mass or pile, rounded masses with a flat base, limited horizontal growth but grow upwards
High Cloud Family
Generally found above 6 kilometers high. They are thin and white, composed of ice crystals.
Includes cirrus, cirrocumulus, cirrostratus
Cirrus Clouds
High cloud family
Cirrocumulus Clouds
High cloud family
Cirrostratus Clouds
High cloud family
Middle Cloud Family
Occur between 2 and 6 kilometers up. Can be stratiform or cumuliform. Composed of liquid water
Includes altocumulus and altostratus
Altocumulus Clouds
Indicate settled weather conditions
Middle Cloud Family
altostratus Clouds
Associated with changing weather
Middle Cloud Family
Low Cloud Family
Found below 2 kilometers, can be individual clouds or groups. The term overcast refers to these clouds, associated with drizzly rain.
Includes stratus, stratocumulus, nimbostratus (nimb is the prefix given to precipitation clouds)
Stratus Clouds
Low Cloud Family
Stratocumulus Clouds
Low Cloud Family
Nimbostratus Clouds
Low Cloud Family
Vertical Cloud Family
Grow from low bases up to 15 kilometers high. Little horizontal spread, growth is upwards
Include cumulus (fair weather clouds) and cumulonimbus (storm clouds)
Cumulus Clouds
Vertical Cloud Family
Cumulonimbus Clouds
Vertical Cloud Family
Fog
Technically speaking there is no difference between clouds and fog accept their location, fog being ground level. Most clouds form when adiabatic cooling takes place, but it rarely uplifts. Fog is formed when air at the Earth's surface cools to its dew po
Radiation Fog
Results when the ground loses heat through radiation, radiated heat moves upward leaving cool air behind. When air cools to the dew point, fog occurs
Advection Fog
Develops when warm, moist air moves over a cold surface (such as snow or cold ocean currents). Air moving from sea to land is the most common source.
Orographic Fog
Created by adiabatic cooling when humid air climbs a topographic slope
Dew
Originates from terrestrial radiation. Nighttime radiation cools objects at the Earth's surface.
Adjacent air is cooled in turn by conduction. If air cools to saturation then excess moisture must come out.
Visual Determination of Stability
Unstable air is associated with upward movement and will generate vertical clouds. Stable air will do horizontal clouds.
Characteristics of Stable Air
Not buoyant, clouds tend to be stratiform or cirriform, and precipitation will be drizzly
Characteristics of Unstable Air
Buoyant, clouds tend to be cumuliform and precipitation will be showery
Collision-Coalescence Process (Precipitation)
Cloud droplets merge together and large drops overtake the small ones.
Precipitation in cold clouds
Precipitation can form in cold clouds by three different processes:
1) Accretion
2) Aggregation
3) Bergeron-Wegener Process
Accretion (Precipitation in cold clouds)
Ice crystal collides with supercooled water droplets and freeze so ice crystals can grow quickly
Aggregation (Precipitation in cold clouds)
Ice crystals collide to for ma single ice particle.
Rain
Most common form of precipitation
Snow
Solid precipitation, form by sublimation
Sleet
Small raindrops that freeze during descent and reach the ground as small ice pellets.
Glaze
Freezing rain/black ice
Hail
clouds that form hail have a lower section that is above freezing and an upper section below freezing with updrafts
Convergent lifting of air
Occurs when air masses meet and are forced to rise vertically.
Local Convectional Lifting of air
Anywhere the land is warmer, air will rise
Orographic Lifting of air
When air moving horizontally encounters a mountain it must rise over the crest. It cools as it rises and creates clouds/often precipitation
Frontal Lifting of Air
Not a mountain range but masses of air create the same effect. Fronts can lift air and create clouds and large amounts of precipitation
Global Patterns of high precipitation
Areas of a lot of instability due to convection and convergent uplifting, most prominent near equator.
Global Patterns of low precipitation
Western side of continents in subtropical areas, high latitudes
Acid Precipitation
Sulfur and nitrogen ocides combine with water to form acids that fall to the earth.