The relationship between solar radiant energy and the earth

As the center of our galaxy, the sun is always under the strong impact of thermonuclear fusion, tumbling huge waves of molten water, while emitting and absorbing the different wavelengths of the sun’s interior in the thermonuclear state. Visible light or electromagnetic current radiation. In the development, research and actual utilization of solar radiant energy, in order to eliminate the random and non-linear influencing factors that we do not grasp for the time being, and to grasp the main contradiction, scientifically set our initial development and research on solar radiant energy. As for the benchmark conditions, the scientists agreed to simplify the sun to a black body with an average surface temperature of 6000K and continuous radiating visible light or electromagnetic radiation energy into the universe with strong electromagnetic waves of 0.3~3μm.

Although the average density of the sun is only 1/4 of the density of the earth; but because of its huge volume, it is 1.3×106 times the volume of the earth; the total mass is 3.32×105 times the mass of the earth; the earth as a solar system is inferior to Mercury and Venus After that, the third closest planet to the Sun is on an elliptical orbit with a long radius of 1.52×108km and a short radius of 1.47×108km, and an eccentricity of about 3%. It revolves around the sun in a constant period of minutes and 46 seconds. Scientists define the average distance between the sun and the earth in an elliptical orbit of the earth around the sun: 1.495×108km as one astronomical unit. On this spherical surface with a radius of one astronomical unit, the earth intercepts the solar radiation energy of the total energy of 2.2 billionth of the solar radiation into the entire universe with its own circular cross-sectional projection area. If we calculate with the average temperature of the sun’s surface 600, the possible solar radiant energy within the projection range of the circular cross-section of the earth is as high as 1.73x1018kWh per year. According to scientific observations, 34% of the total radiant energy is reflected by the earth’s atmosphere and clouds into space Gone; 19% is absorbed by the earth’s atmosphere and forms the so-called “meteorological energy”; since 71% of the earth’s surface is covered by the ocean, the power of solar radiation energy that can actually reach the earth’s surface is only about 8.5×1012kW; The energy density of solar radiation that actually reaches the ground and is collected is actually lower. Nevertheless, the total energy of solar radiant energy reaching the ground within a year is still as high as 1018kWh, which is equivalent to more than ten times the energy released by all fossil fuel resources on the earth. In fact, wind energy (air kinetic energy), water energy, ocean wave energy and temperature difference energy, part of the tidal energy and biomass energy on the earth all directly or indirectly come from the sun and its radiant energy. Someone has calculated that if all the solar radiation energy on the ground of five square kilometers in one day is collected, the energy available is equivalent to the energy released by the explosion of a 20,000-ton TNT atomic bomb. The total theoretical resource of solar energy in my country is about 1.47 x 10.8 billion kWh/a.

The earth is in its own orbit, while rotating from west to east around its own constant axis of rotation, it is also revolving around the sun in an elliptical orbit around the sun. The earth’s rotation cycle is one day and night (24h); from the perspective of geometric relations, the angle of the earth’s self-rotation per hour relative to the sun, that is, the “solar hour angle” (ω) rotates 15° per hour from east to west. Because there is an angle of 66°33′ between the rotation axis of the earth and the elliptical orbit plane that revolves around the sun, also known as the “ecliptic plane”, and the orientation of the rotation axis of the earth in the universe (that is, the direction of the Big Dipper) is always the same. , Therefore, there is a constant angle of 23°27′ between the earth’s equatorial plane and the ecliptic plane. In other words, the connection between our virtual center of the earth and the center of the sun. That is, at noon, the light from the sun straight to the earth will periodically sweep back and forth between the Tropic of Cancer (ie latitude ±23.5°) during the year: this angle is called The “sun red angle” (δ) is on the surface of the earth. The direct point of the sun’s declination (δ) on average every month. It moves 8° on the latitude line (back and forth) of the regression zone in the south and north directions of the earth; and it moves 360° every day on the longitude line in the east and west directions.

The earth is on the “perigee” (1.471 x108km) in an elliptical orbit around the sun on January 1 of the Gregorian calendar every year: it reaches the “apogee” (1.52 x108km) on July 1; the sun is shining on the Tropic of Cancer in the northern hemisphere on June 21 ( The summer solstice); December 22, the sun is shining on the Tropic of Capricorn in the southern hemisphere (winter solstice). On March 21 and September 23 each year, the sun is shining on the equator (that is, the vernal equinox and autumnal equinox), and the sun’s declination (δ) is zero at this time. Since the sun’s elliptical orbit has a deviation of 3%, it is necessary to “fine-tune” the calendar through normal years and leap years.

The relationship between solar radiant energy and the earth