FINALS (JEREMY) Flashcards
What is the importance of water vapour in the atmosphere?
1) Water vapour condenses and forms into both liquid and solid cloud particles that fall onto earth as precipitation.(1)
2) Water vapour also releases a large amount of heat, called latent heat (2), when it changes from vapour into liquid water or ice.
3) Water vapour is a potent greenhouse gas (3) because it strongly absorbs a portion of the earth’s outgoing radiant energy.
4) Water vapour is an active absorber and emitter of infrared radiation, affecting the heating and cooling of the atmosphere and surface.
5) Therefore, water vapour plays a significant role in earth’s heat energy balance (4)
If the earth’s surface continually radiates energy, why doesn’t it become colder and colder?
It does not become colder due to the greenhouse gases that are present in the lower atmosphere. Greenhouse gases will emit and absorb infrared radiation ensuring heat balance on earth.
In an atmosphere with little or no greenhouse gases, the earth’s surface would constantly emit Infrared Radiation upwards back into space, both during the day and night. Since incoming energy from the sun would equal the outgoing energy from the surface, the surface would receive virtually no Infrared Radiation from it’s lower atmosphere. This causes the earth’s surface temperature to be quite low, and small amounts of water found on the planet would be in the form of ice.
In an atmosphere with greenhouse gases, the earth’s surface not only receives energy from the sun but also Infrared Energy from the atmosphere. Incoming energy will still equal the outgoing energy, but the added Infrared Radiation energy from the greenhouse gases raises the earth’s surface temperature to a more habitable level.
How do the earth and its atmosphere maintain this yearly energy balance?
The earth-atmosphere energy balance is achieved because the energy received from the Sun balances the energy lost by the Earth back into space. In this way, the Earth maintains a stable average temperature and therefore a stable climate.
Using 100 units of energy from the sun as a baseline the energy balance is as follows, 30 units will be scattered and reflected by the earth, clouds and atmosphere. Out of the remaining 70 units, 19 units will be absorbed by the clouds and atmosphere leaving only 51 units to heat up the Earth’s surface.
Earth’s surface absorbs the 51 units of shortwave radiation energy and additional 96 units of longwave radiation energy from the atmospheric gases and clouds. This 147 units gained by earth are due to shortwave (sun) and longwave (greenhouse gas) absorption and emittance.
Earth’s surface then loses these 147 units through conduction, evaporation and radiation. Thus, showing how the earth-atmosphere balance is achieved.
List four primary ways clouds form, and describe the formation of one cloud type by each method.
Convection
The sun heats up the earth’s surface which then warms the surface air above it. The warm air rises and condenses when it reaches dew point temperature forming clouds. The outer edge of the cloud cools, becomes heavier and sink forming a convection current. Individual clouds form, move away and new clouds grow.
Other methods of cloud formation include, Orographic uplift, Convergence of Surface Air and Uplift along weather fronts.
Describe how the wind blows around highs and lows aloft and near the surface.
in the Northern Hemisphere
In the Northern Hemisphere, the effect of surface friction is to slow down the wind so that, near the ground, the wind crosses the isobars and blows toward lower pressure.
Describe how the wind blows around highs and lows aloft and near the surface
in the Southern Hemisphere
In the southern hemisphere, this phenomenon at the surface produces an inflow of air around a low and an outflow of air around a high. Aloft, away from the influence of friction, the winds blow parallel to the lines, usually in a wavy west-to-east pattern
What are the forces that affect the horizontal movement of air?
Earth surface wind: Surface friction
Wind aloft: Geostrophic force, Pressure gradient force, and Coriolis force.
What is a tidal bore?
bores are formed in inlets exposed to a large tidal fluctuation.
The confined river mouth forces the tidewater to move at a speed faster than the theoretical shallow water wave speed for that depth. The forced wave breaks, forming a spilling wavefront that moves upriver.
Why is the western boundary current stronger, faster, narrow and deeper?
The increased flow on the western sides of the gyres, know as western intensification is caused by the increasing Coriolis effect with increasing latitude.
This causes the east-moving water of the North Atlantic Current to turn sooner toward the equator than the west-moving current to turn toward the pole.
The result is a spread-out and slow eastern boundary (Canary Current) and a concentrated and rapid western boundary (Gulf Stream) currents.
It essentially is a consequential change arising from wind strength and direction with increasing latitude.
