Understanding the Solar Constant

The solar constant is a measure of the average amount of solar electromagnetic radiation received per unit area, perpendicular to the rays, from the Sun at a distance of one astronomical unit (AU). One AU is the average distance from the Earth to the Sun.

This value is not truly 'constant' as it varies slightly due to solar activity and the Earth's elliptical orbit, but it provides a standard reference point for solar radiation reaching the top of Earth's atmosphere.

Standard Value Adopted by World Radiation Centre

Different measurements and standards exist for the solar constant. The World Radiation Centre (WRC), which is part of the World Meteorological Organization (WMO), plays a crucial role in standardizing measurements related to radiation.

According to the standards adopted by the World Radiation Centre, the internationally recognized value for the solar constant is:

• 1367 Watts per square meter (W/m²)

This value represents the solar power incident on a unit area perpendicular to the sun's rays at the mean Sun-Earth distance, outside the Earth's atmosphere.

Analyzing the Options

Let's look at the given options in the context of the standard solar constant value:

1. 1192 w/m ²

   - This value is lower than the standard accepted value.
2. <span>1084 w/m 2</span> - This value is significantly lower than the standard accepted value.
3. <span>1927 w/m 2</span> - This value is much higher than the standard accepted value.
4. <span>1367 w/m 2</span> - This value matches the standard value adopted by the World Radiation Centre.

The units are given as w/m², which should ideally be W/m² (Watts per square meter). The value itself is the key identifier.

Therefore, the standard value of the solar constant as adopted by the World Radiation Centre is 1367 W/m². This value is important in meteorology, climate studies, and solar energy calculations.