Which radiation is incident on outer surface of Earth?

Which radiation is incident on outer surface of Earth?

Solar radiation

What happens when solar radiation interacts with Earth’s surface and atmosphere?

INCOMING SOLAR RADIATION Larger aerosol particles in the atmosphere interact with and absorb some of the radiation, causing the atmosphere to warm. The heat generated by this absorption is emitted as longwave infrared radiation, some of which radiates out into space.

What happens to solar radiation when it hits Earth’s surface?

In total approximately 70% of incoming radiation is absorbed by the atmosphere and the Earth’s surface while around 30% is reflected back to space and does not heat the surface. The Earth radiates energy at wavelengths much longer than the Sun because it is colder.

What is the solar flux of Earth?

approximately 1373 W m−2

What can change the solar constant?

The solar constant actually varies by +/-3% because of the Earth’s slightly elliptical orbit around the Sun. The Sun-Earth distance is smaller when the Earth is at perihelion (first week in January) and larger when the Earth is at aphelion (first week in July).

What is solar constant formula?

The specific value at Earth of 1,361 W/m2 is called the “solar constant”. In order to calculate the total amount of energy arriving at Earth, we need to know how much area is being lit. KS = solar insolation (“solar constant”) = 1,361 watts per square meter. RE = radius of Earth = 6,371 km = 6,371,000 meters.

Why is the solar constant important?

Knowledge of the exact value of the solar constant is very important for the study of heat-exchange processes in the earth’s atmosphere and for the investigation of processes occurring in the sun. This method permits the absorption and scattering of sunlight by the earth’s atmosphere to be taken into account.

How do we measure solar radiation?

There are two important types of instruments to measure solar radiation:

1. Pyrheliometer is used to measure direct beam radiation at normal incidence.
2. Pyranometer is used to measure total hemispherical radiation – beam plus diffuse – on a horizontal surface.
3. Photoelectric sunshine recorder.

What you mean by solar constant?

Solar constant, the total radiation energy received from the Sun per unit of time per unit of area on a theoretical surface perpendicular to the Sun’s rays and at Earth’s mean distance from the Sun. It is most accurately measured from satellites where atmospheric effects are absent.

What is another name for solar radiation?

Hypernym for Solar radiation: flare, solar wind, insolation, solar flare, solar prominence.

How do you convert solar radiation to sunshine hours?

The value of KT = 0.3142 corresponding to the relative sunshine hour (RSSH) is about 0.3103 and measured global solar radiation is 12.13 MJ/m^2/day in the month of August. It indicates that the relative sunshine duration and clearness index values are the lowest in month of August.

How many hours of sunlight does a solar panel need?

So, even though the average day is exactly 12 hours, the power you actually get on your panels is equal to about 5 to 6 hours of full sun per day. Since the typical modern solar panel is about 12% efficient, you will get about 700 watts per square meter of panel.

How do you calculate global horizontal irradiance?

Global Horizontal Irradiance (GHI), from the hemisphere above a horizontal plane surface, is a combination of DNI, corrected for the angle of incidence of the beam (θ), and Diffuse Horizontal Irradiance (DHI). GHI = DNI*cosθ + DHI. All these parameters are measured in units of W/m2.

What is direct normal irradiance?

the amount of solar radiation received per unit area by a surface perpendicular (normal) to the rays that come in a straight line from the direction of the sun at its current position in the sky.

What does W m2 measure?

The solar irradiance is measured in watt per square metre (W/m2) in SI units. Solar irradiance is often integrated over a given time period in order to report the radiant energy emitted into the surrounding environment (joule per square metre, J/m2) during that time period.

What is global irradiance?

Global Horizontal Irradiance (GHI) is the total solar radiation incident on a horizontal surface. It is the sum of Direct Normal Irradiance (DNI), Diffuse Horizontal Irradiance, and ground-reflected radiation.

What is the difference between irradiance and irradiation?

(Solar) irradiation – The sum of the energy falling on a surface in a given time-period, originating from the sun, measured in MJ/m2. (Solar) irradiance – The power or instantaneous rate of energy received by a surface, originating from the sun, measured in W/m2.

How do you calculate direct normal irradiance?

The hourly direct irradiance on a horizontal surface is obtained by subtracting the hourly global and the hourly diffuse components. Then, the hourly direct normal irradiance is computed taNing into account the latitude, the solar declination of the day and the solar angles at the considered instants.

What are the types of solar radiation?

The three relevant bands, or ranges, along the solar radiation spectrum are ultraviolet, visible (PAR), and infrared. Of the light that reaches Earth’s surface, infrared radiation makes up 49.4% of while visible light provides 42.3% 9. Ultraviolet radiation makes up just over 8% of the total solar radiation.

What is Circumsolar radiation?

Circumsolar radiation can be described by the radiance emanating from the circumsolar region and the sun as a function of the angular position relative to the center of the sun.

What is diffuse irradiance?

Diffuse Horizontal Irradiance is the amount of radiation received per unit area by a surface that does not arrive on a direct path from the sun, but has been scattered by molecules and particles in the atmosphere. Basically, it is the illumination that comes from clouds and the blue sky.

What is the difference between direct and diffuse radiation?

In simple terms, direct radiation has a definite direction but diffuse radiation follows a much more scattered, uncertain path. Because when the radiation is direct, the rays are all travelling in the same direction, an object can block them all at once.

What causes diffuse radiation?

Diffuse sky radiation is solar radiation reaching the Earth’s surface after having been scattered from the direct solar beam by molecules or particulates in the atmosphere. Under an overcast sky, there is no direct sunlight, and all light results from diffused skylight radiation.

What is beam and diffuse solar radiation?

Beam radiation is the solar radiation received from the Sun without having been scattered by the atmosphere. Diffuse radiation is that received from the Sun after its direction has been changed by scattering by the atmosphere.