7: Atmosphere Flashcards
What is the atmosphere? What is it composed of?
- Layer of air surrounding earth, gravity keeps it from floating away
- 78% nitrogen, 21% oxygen, <1$ CO2, O3, water vapour, particles (pollen, pollution, dust)
What is atmospheric pressure? Avg?
The force exerted due to particles colliding, avg 101.3kPa at sea level
What is a kPa?
100kg of force over 1m^2
Where is air thinnest?
Higher altitude, bc there are less particles, less collisions
Why does warm air rise?
Temp increase = volume of particles increase = density decrease
What is wind?
Air particles moving from high pressure to low pressure ares (less concentration of particles)
Name the layers of the earth, how high they are, and their characteristics.
Troposphere: 0-15km, meteorological phenomena
Stratosphere: 15-50km, ozone, temp increase
Mesosphere: 50-80km, cold, few particles
Thermosphere: 80-500km, HOT, absorbs sun rays, aurora borealis/shooting stars here
Exosphere: 500km+, temp?, satellites, no air
What is general atmospheric circulation?
Warm air from equator rises to poles and cold air from poles flows towards equator (convection mvmt)
What is the coriolis effect?
Air masses deviating perpendicularly from their initial trajectory due to the earth’s axis rotation. AKA prevailing winds (winds circulating in loops)
Which direction does the coriolis effect go? In which layer of the Earth?
Right in the Northern hemi, left in the Southern; troposphere
What meteorological phenomena are influenced by the coriolis effect?
Cold/warm fronts, cloud formation
Name the 3 prevailing winds, their direction, and location in latitude
Polar cell (60N/S to pole): easterlies Ferrel cell (30-60N/S): westerlies Hadley cell (equator-30N/S): easterlies
What affects wind to blow in a certain direction?
Pressure
What are jet streams?
Powerful winds blowing between cells at high altitude (west>east)
How many jet streams are there? Names?
2 per hemi: subtropical, polar
What are air masses? What do they influence?
Large expanses of atmosphere with same temp/humidity; weather
What are the 7 air masses and their locations?
Continental arctic (territories) Continental polar (provinces) Continental tropical (south USA) Maritime polar (oceans near Canada) Maritime tropical (oceans near Mexico/south USA)
Cont = dry, marit = humid
What are fronts?
Transition zone where two opposite air masses meet, causing a change in temp and humidity
Warm front characteristics
Slides beneath cold, slow moving, dry air, little precip
Cold front characteristics
Pushes warm up, fast moving, humid, lots of precip
Anticyclones VS depressions
Anti: high pressure centre, sunny dry, cold air, air falls
Dep: low pressure centre, clouds, precip, air rises
Anticyclones/depressions relate to fronts how?
Anti = warm front Dep = cold front
What are cyclones/hurricanes?
Strong depression areas forming over tropical warm waters, spiral (800km wide), violent winds, looooots of rain, LP area, floods, landslides, destroy infrastructure
What is the greenhouse effect?
Natural process allowing Earth to retain some heat from sun
How does the greenhouse effect work?
Sun rays absorbed by ground, emits infrared rays when heated into atmo, some trapped by ozone and sent back to earth to keep it warm
What does greenhouse gas contain?
CO4 (methane), CO2, NO2 (nitrous oxide), water vapour
Is methane or carbon dioxide stronger? By how much?
Methane, 21x
List sources of methane
Animal digestion, rice farming, manure, decomposing waste, natural gas distribution, melting permafrost
Where does NO2 come from?
Fertilizers, chemical processes
What are atmospheric contaminants?
Abundance of polluting substances mixing with air to create toxic subs
How does wind affect pollution/atmo. contaminants?
Spreads it around over hundreds of KMs due to prevailing winds
Name the 4 atmospheric contaminants
CFCs (cooling systems, Cl atoms destroying O3 when bonded)
SO2, NO2 (acid rain, smog)
Hg, As, Pb (oil, coal combustion)
Dust, airborne particles (factory chimneys, car exhausts)
What is smog?
Mix of smoke, fog, pollutants caused by HP system preventing it from rising into atmo
Describe the ozone layer
20-30km in stratosphere, absorbs UV rays, measured in dobson units (100DU = 1mm)
How is tropospheric O3 formed?
NOx and UV rays mix
Define wind energy + pros and cons
Harvesting mechanical wind power and transforming it into energy
Pros: renewable, no greenhouse gas
Cons: machines not recyclable, expensive, wind unreliable (strength/amt), loud, energy cannot be stored
Define solar radiation/energy
Energy created through fusion travelling in electromagnetic waves (8min)
1hr of sun = enough energy for a year for entire world
Which solar radiation waves reach earth?
Infrared, visible light, UV
Pros and cons of sun energy
Pros: renewable, green
Cons: expensive, unreliable, sometimes lots of panels needed, not very efficient (yet), energy cannot be stored
What 3 technologies can harvest the sun’s energy?
Photovoltaic cells (electrons set off by light creating electricity, made of silicone) Passive heating systems (planned house orientation towards sun, concrete absorbs excess heat to release when sun sets) Solar collectors (large glass panels using energy to heat water or air passing under through pipes)
