The energy that the earth intercepts from the sun is only about two billionth of its total energy. Solar radiation (energy) represents more than 99.9 percent of the energy that heats the earth , but the solar energy is not distributed equally over the earth’s land sea surface. It is this unequal heating that accounts for the ocean’s currents and creates the wind, which transport heat from the tropics to the poles in an attempt to create a balance of energy. The temporal and spatial variations in the amount of solar energy reaching the earth is caused by the motions of the earth relative to the sun and by variations in the earth’s surface.
The earth’s two principal motions, rotation and revolution affects the weather on the earth. Rotation is the spinning of the earth about it’s axis. This rotation one every 24 hours produces the daily cycle of daylight and darkness. On the other hand the revolution is the movement of the earth in its orbit around the sun. This movement affects the seasons enjoyed by the earth. The variations in temperature are also connected with the distance of the earth and the sun. because the earth’s orbit is not perfectly circular, the distance varies slightly during the course of a year.
The shortest distance 147 million kilometer from the sun occurs, on or about the 3rd of January. This position is called perihelion. On July 4 th the earth is farther away from the sun the aphelion with a distance of 152 million kilometers.
This combination of revolution and the distance from the sun causes the seasons. The seasonal variation in the altitude of the sun affects the amount of energy received at the earth’s surface in two ways. First, when the sun is directly overhead (at a 90 degree angle). The solar ray are most concentrated. The lower the angle the more spread out and less intense is the solar radiation that reaches the surface. The second, the angle of the sun determines the amount of atmosphere that the rays must travel through.
If the sun is directly overhead, its rays pass through a thickness of only 1 atmosphere, where as rays entering at a 30 degree angle travel through twice the amount and 5 degree rays travel a thickness roughly equal to 11 atmosphere. The longer the path, the greater is the chance for absorption, reflection and the scattering by the atmosphere, which reduces the intensity at the surface. This same effect explains the difference between the heat of the midday sun and the beauty of the setting sun, and position north or south of this location, the
readings will be applicable. These readings are intended to provide or force a link between mathematical ideas, and theory from climate and the ocean.
Each lesson plan can be considered a mini lesson and can be used for the duration of one or two lessons. The main focus is to provide background information to mathematical problems that are pertinent to the topic climate and weather. Each lesson plan will be independent of each other and will cover ideas as diverse as sun - earth radiation, to weather prediction. In some cases sufficient information will be found in the body of the unit, in some cases suggestion will be made for students to do research.
By using a section of the unit over time the students will experience various concepts from climate and weather thus assisting them in making the connections between mathematics and the content.