Oddly enough the earth is about 3,000,000 miles nearer to the sun in our northern winter than it is in summer. Yet it is much warmer in summer.The reasons are not caused by different distances from the sun, but by the slant of the earth's axis as it moves around the sun. Scientists have learned that the Equator of the earth is tilted 23 degrees to the path of the earth around the sun.
As the earth moves around the sun, the earth's axis always points in the same direction, towards the North Star. For this reason, during part of the year the North Pole tilts towards the sun and part of the year away from it. When the North Pole is inclined towards the sun, the Northern Hemisphere has its summer. When the North Pole is inclined away from the sun, the Northern Hemisphere has its winter. In the Southern Hemisphere these seasons are reversed.
The difference in weather with the seasons occurs because the sun's rays are more slanting in winter and less slanting in summer. Slanting rays produce less heat for two reasons. One is that they scatter their heat over a larger area of the earth's surface. The other is that they lose more of their heat in passing through the atmosphere.
Other factors, primarily water, land, and altitude, help regulate the climate. Water has a stabilizing effect and helps prevent great changes in temperature. Land does not store up heat (the way the ocean does), so big temperature changes can take place over large land areas. Air grows less dense with altitude and cannot absorb as much heat as at sea level. So the higher the altitude, the lower the temperature will be.
As the earth moves around the sun, the earth's axis always points in the same direction, towards the North Star. For this reason, during part of the year the North Pole tilts towards the sun and part of the year away from it. When the North Pole is inclined towards the sun, the Northern Hemisphere has its summer. When the North Pole is inclined away from the sun, the Northern Hemisphere has its winter. In the Southern Hemisphere these seasons are reversed.
The difference in weather with the seasons occurs because the sun's rays are more slanting in winter and less slanting in summer. Slanting rays produce less heat for two reasons. One is that they scatter their heat over a larger area of the earth's surface. The other is that they lose more of their heat in passing through the atmosphere.
Other factors, primarily water, land, and altitude, help regulate the climate. Water has a stabilizing effect and helps prevent great changes in temperature. Land does not store up heat (the way the ocean does), so big temperature changes can take place over large land areas. Air grows less dense with altitude and cannot absorb as much heat as at sea level. So the higher the altitude, the lower the temperature will be.