Energy

- The pump found in the tropical oceans is responsible for the movement of air and the surface ocean over most of the globe. The energy source that drives this pump is solar radiation from the sun.

- The second pump is the deep ocean circulation which is also driven by the sun.

- The third pump is the heating of the earth’s interior by radioactive decay and radiation of heat causes plate tectonics and continents to move. This long term pump has ceased in Mars.

- The winds and ocean currents redistribute the energy received from the Sun

- Air moves from high pressure areas to low pressure areas horizontally due to horizontal differences in pressure.

- As a parcel of air warms up it becomes more buoyant and the air rises. Warmer air has less density.

- Pressure differences among air masses are typically related to the distribution of surface temperatures

- The radiation reaching the Earth is spread over larger and larger areas as we move from the equator to the poles. You get more light per unit area at the equator than at high latitudes.

- The incoming solar radiation varies with latitude and seasons, whereas the outgoing terrestrial radiation depends on the temperature at the surface and atmosphere.

- Primary causes for temperature distribution on earth are because it’s warmer at the equator and colder at higher latitudes.

- The solar radiation absorbed at the surface varies with cloud cover and atmospheric absorption.

- Heated air rises at the equator causing air to move towards the equator. This converging air makes up the intertropical convergence zone.

- Rising air cools which causes it to loose its water in the form of rain.

- Areas of rising air cause low pressures.

- The warmer stratosphere acts as a barrier to the rising warm air causing it to spread out and diverge. As the air diverges it becomes more and more cooler and it sinks at 30 degrees N/S of the equator (Hadley Cell)

- Most of the earth’s deserts are located at about 30 degrees N/S of the equator. Descending air causes an area of high pressure at this 30 degrees N/S

- Hadley Cell: the convergence occurring in the tropics and divergence some 30 degrees N/S of it is called the Hadley Cell.

- The Hadley Cell and the ITCZ are not continuous around the globe.

- The equatorward-moving cold air meets the warm air moving poleward from the subtropics producing a zone of steep temperature gradients called the polar front zone at approximately 60 degrees N/S latitude.

- Cold air sinks at the poles producing high pressures

- Because we have high and low pressure area, we would expect winds to blow out of the high pressure zones at the poles and 30 degrees N/S towards the low pressure zones at the equator and at about 60 degrees N/S.

- The east-west movements of surface winds are the result of the Coriolis Effect.

- The coriolis effect is a result from forces acting on an object moving on a rotating body

- There is no coriolis effect at the equator.

- In the Northern Hemisphere, moving objects go to the right and in the Southern Hemisphere moving objects go to the left.

- The distribution of surface winds is a combination of heating, pressure gradients, and Coriolis Effect.

- meteorologists refer to winds in terms of the direction from which they blow

- in mid latitudes (35-55 degrees N/S) you will find westerly winds as a result of air moving towards 60 degrees N/S and coriolis effect

- in high latitudes you will find easterly winds

- at the tropics (25-5 degrees N/S) you will find easterly winds called the northeast and southeast trade winds as a result of low pressure and coriolis effect

- At the equator you will find light winds that change direction frequently. These winds are referred to as doldrums.

- Winds around high pressures in the northern hemisphere flow clockwise aka anti-cyclonic flow.

- Winds around high pressures in the Southern Hemisphere flow counter-clockwise aka cyclonic flow

- Winds around low pressures in the northern hemisphere blow counter-clockwise