What is the Sun's energy content at the Earth's equator?

In summary, the solar constant is an average of a varying value that fluctuates by 6.9% due to the Earth's varying distance from the Sun.
  • #1
royp
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TL;DR Summary
What is the energy content of the sun rays falling on the equator in summer months
Hello,

I am looking to find out the energy (or power) content of the sunlight incident on the equatorial region during summer months. I assume, this is highest in that region. I actually want the direct energy content - not, say, the electrical output from a solar panel. This could be, in some way, a measure of heat. This may be available as KWh/square meter which will be most preferable.

Many thanks in advance for your help.
 
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  • #3
royp said:
I am looking to find out the energy (or power) content of the sunlight incident on the equatorial region during summer months. I assume, this is highest in that region. I actually want the direct energy content - not, say, the electrical output from a solar panel. This could be, in some way, a measure of heat. This may be available as KWh/square meter which will be most preferable.

Note that the solar insolation at the equator actually peaks at the equinoxes (when the sun is directly overhead) and is lower in summer and winter. Also, note that the insolation is a power density in kW/square meter, and would need to be integrated over some time period to give an energy density. At the Earth's surface it is about 1kW/m^2, as described in the article @Borek posted.
 
  • #4
Borek, phyzguy : Many thanks! This will serve my purpose very well.
 
  • #5
Borek said:

At first I thought this was some kind of scientific version of "mansplaining"

The actual direct solar irradiance at the top of the atmosphere fluctuates by about 6.9% during a year (from 1.412 kW/m² in early January to 1.321 kW/m² in early July) due to the Earth's varying distance from the Sun...

How on Earth can a constant vary?
But then I saw:

The solar constant is an average of a varying value.

Ok then.
 
  • #6
Yes, the name is a bit of a misnomer.
 
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  • #7
Borek said:
Yes, the name is a bit of a misnomer.

Were I a bit more ambitious, I'd go back through all 12 years of my PF posts, and put in a "± 6.9%" for all my solar experiments.
But, I'm not in the slightest bit ambitious, so, never mind.
 
  • #8
OmCheeto said:
How on Earth can a constant vary?
You are right to question some sloppy terminology.
Bear in mind that the Earth's orbit round the Sun is not an exact circle. That means, despite any tilt or atmospheric factors, it can't be a 'constant'. It's a bad idea to get too hung up on 'words' when experimental evidence challenges them.
 

1. What is the Sun's energy content?

The Sun's energy content refers to the total amount of energy emitted by the Sun. This energy is primarily in the form of electromagnetic radiation, including visible light, infrared radiation, and ultraviolet radiation.

2. How is the Sun's energy measured?

The Sun's energy is measured in watts per square meter (W/m²). This unit of measurement represents the amount of energy that falls on a one square meter area at the Earth's surface.

3. What is the Earth's equator?

The Earth's equator is an imaginary line that divides the Earth into the Northern Hemisphere and Southern Hemisphere. It is located at 0 degrees latitude and is the widest part of the Earth's surface, measuring approximately 40,075 kilometers (24,901 miles) in circumference.

4. How much of the Sun's energy reaches the Earth's equator?

On average, about 1361 watts per square meter (W/m²) of the Sun's energy reaches the Earth's equator. However, this amount can vary depending on factors such as the Earth's tilt, atmospheric conditions, and cloud cover.

5. What is the impact of the Sun's energy at the Earth's equator?

The Sun's energy at the Earth's equator is responsible for driving weather patterns, ocean currents, and the Earth's climate. It also provides the energy necessary for photosynthesis, which is the process by which plants convert sunlight into chemical energy.

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