Sem#2 Chap 1 Flashcards
Air
A mixture of gases surrounding the earth.
Includes carbon dioxide and hydrogen
99.9% of earths air is within _____ of the earths surface? (in km)
0-50km
Wind
The horizontal movement of air
Percipitation
Water falling from the sky. Liquid or solid
Storms
When wind and precipitation are dangerous
Atmospheric Hazards, examples
Blizzard and Hurricane
Water Vapor (not exactly a definition)
Percentage varies depending on time and place.
Constantly changes phase to liquid and solid.
Aerosols
Liquid or solid particles
Dust, soil, salt, ash, pollen, bacteria mold.
Creates haze when present with water vapor.
Sizes of water particles in air
Water molecule: 0.0000003
Aerosol: 0.0004–0.01
Cloud droplet: 0.01–0.1
Drizzle: 0.1–0.5
Small raindrop: 0.5–1.0
Large raindrop: 1.0-4–0
Very large raindrop: 4.0–8.0
Clouds
Clouds consist of water droplets
Clouds consist of ice crystals
Air Pollution is and is caused by
Anthropogenic gases and aerosols create polluted air.
Primary Pollutants
Emitted directly from a source
Examples: Vehicle exhausts and industrial processes.
Secondary Pollutants
When primary pollutants react together with sunlight.
Examples: Ozone and Acid rain
Pollution in the late 19th century was____ (mainly consisted of)
Smog:
Soot, Carbon monoxide, and sulfur bearing gases.
Pollution today is called _____
Photochemical Smog:
When primary pollutants react with other gases and sunlight.
Examples: Ozone and Nitric acid aerosols
Class Question #1
What was the societal impact of the smog event experienced in London,
December 5–9, 1952?
a) The city mandated that scrubbers be placed on all industrial
smokestacks.
b) A pollution tax was created, thereby increasing the cost of petrol
and electricity across London.
c) Over 6,000 people died.
d) An executive order from the mayor created even/odd driving days,
based on a vehicle’s license plate number.
(No given answer)
Weather
Specific atmospheric conditions at a time and place.
Meteorologists study and predict weather
Climate
Average weather conditions over many decades.
Climatologists study and predict climates.
Atmospheric conditions describing weather:
- Temperature: the air’s hotness or coldness
- Pressure: the weight of air above a location
- Relative humidity: the presence of water vapor
- Wind direction: the compass direction from which the air moves
- Wind speed: the velocity of air’s horizontal movement
- Visibility: a measure of how far one can see through the air
- Cloud cover: the portion of sky covered by clouds
- Precipitation: the amount of water and/or ice falling to the ground
Temperature:
Air molecules average speed.
Kinetic energy of air molecules.
KE = MV^2
Thermal Energy
The sum of all kinetic energy in a material
Heat
When thermal energy is transferred.
Always flows from hot to cool materials
Atmospheric Pressure
The force applied by air on a specific surface area.
The weight of a column of air.
With no wind, air pressure is the same in all directions.
Molecules move ______ in hot air. And hot air is _____.
apart, less dense
Molecules move ______ in cold air. And cold air is _____.
closer together, denser
Air pressure varies how often?
Daily and seasonally
Air pressure and density
decrease as altitude ______.
increases
Vapor pressure
The portion of air pressure exerted by water vapor.
At a specific temperature:
Dry air has a ______ vapor pressure.
Moist air has a _______vapor pressure.
- Dry air has a lower vapor pressure.
- Moist air has a higher vapor pressure.
Saturated air:
- Contains all the water vapor it can hold
- Dictated by temperature and atmospheric air pressure
Saturation vapor pressure:
- The atmosphere’s vapor holding capacity
Relative Humidity
Measures how close the air is to saturation.
Determined by 2 variables:
* The amount of water vapor in the air
* The air’s vapor capacity (which is temperature dependent)
Air’s vapor capacity increases as temperature ________.
Increases
Relative Humidity (RH) formula
(vapor pressure / saturation vapor pressure) x 100
Dynamic Pressure
The stress caused by moving a fluid
Wind direction
the direction from where the wind blows
Wind speed
The horizontal rate of air movement
Wind bards
graphically display wind speed and direction.
Streamlines
graphically display wind as parallel lines.
Visibility
how far one can see through the air
Pure air is _______. (visibility wise)
Transparent
Cloud cover
the proportion of the sky containing clouds
Precipitation rate
how fast precipitation occurs (mm/hr)
Total precipitation
cumulative amount during a time period
Total snowfall
accumulated depth or water equivalent
Radar systems transmit pulses of _____.
microwaves,
Microwaves return to antenna after
hitting rain and hail.
Microwaves travel at _______.
Speed of light
Radars can also measure ______
Altitude of rain and hail
Radar reflectivity
the strength of the returned signal
High reflectivity
heavy rain
Low reflectivity
Light drizzle
Thermometers measure ______.
air temperature
Barometers measure ______.
air pressure