Why does sun intensity vary?
The angle at which the rays from the sun hit the Earth determines this intensity. The sun's angle — and hence intensity — varies significantly depending on a particular spot's geographic location, the time of year, and the time of day.
How does the intensity of the sun’s light vary with different seasons?
This tilting leads to a variation of solar energy that changes with latitude. This causes a seasonal variation in the intensity of sunlight reaching the surface and the number of hours of daylight. The variation in intensity results because the angle at which the sun's rays hit the Earth changes with time of year.
What is the intensity of sunlight?
At Earth's average distance from the Sun (about 150 million kilometers), the average intensity of solar energy reaching the top of the atmosphere directly facing the Sun is about 1,360 watts per square meter, according to measurements made by the most recent NASA satellite missions.
Which factors affect the intensity of sunlight on Earth?
The amount of sunlight reflected depends on the sun's angle, wavelength, and weather conditions. Of the light that reaches the water's surface, approximately 5-10% is reflected 1.
Does the intensity of the sun change?
The total energy coming from the Sun only varies by about 0.1% over each 11-year cycle. For a long time scientists didn't notice it either, which is why the Sun's intensity is called, ironically, the "solar constant." The intensity of the Sun varies along with the 11-year sunspot cycle.
Why is the intensity of sun less in the morning and evening?
The sun rays fall straight on the surface at noon and there is very less scattering of rays. Due to less scattering, the sun rays are brighter. In the morning and evening, the scattering of the sun rays is more as the rays fall in a slanting manner.
What are the causes for the variation of sunlight at different places?
The causes of variation of sunlight at different places is due to difference in equator as well as difference in latitude and longitude.
What is the effect of intensity of light?
Intensity cannot change the cut off frequency or stopping potential. High intensity means more number of photons, so chances of hitting to electron by them increase and hence more photo electron are emitted i.e., photo current increases.
How is sunlight intensity measured?
Lighting professionals use a light meter (also called an illuminance meter or lux meter) to measure the amount of light in a space/on a particular work surface. The light meter has a sensor that measures the light falling on it and provides the user with a measurable illuminance reading.
What causes the intensity of light to be lower in the winter in locations other than the equator?
During winter, the Northern Hemisphere leans away from the sun, there are fewer daylight hours, and the sun hits us at an angle; this makes it appear lower in the sky.
How does variation in the sun’s intensity cause global warming?
No. The Sun can influence Earth's climate, but it isn't responsible for the warming trend we've seen over recent decades. The Sun is a giver of life; it helps keep the planet warm enough for us to survive. We know subtle changes in Earth's orbit around the Sun are responsible for the comings and goings of the ice ages.
Why does the sun feel more intense?
Radiation from the sun is more than matched by convection to the air. Face the sun and your bare skin receives heat by radiation. The sun delivers about 1400 watts of energy per square metre (W/m2) to Earth, but the atmosphere absorbs and reflects much of this.
What causes variations in the length of daytime?
As the Earth moves around the Sun, the length of the day changes. The length of day at a particular location on Earth is a periodic function of time. This is all caused by the 23.5-degree tilt of the Earth's axis as it travels around the sun.
Why is there variation in day and night?
Variations in the length of day and night time from season to season on the earth's surface is due to the axial tilt of earth's rotation axis with respect to its orbital axis.
What causes the intensity of light?
The intensity varies with the distance from the source and the power of the source. Power is a property of the light source that describes the rate at which light energy is emitted by the source. Power is often expressed in units of watts.
How would you describe the intensity of light?
It is measured in footcandles or lux – it is the amount of light (lumens) falling on a surface (over any given square foot or square meter). Therefore, light intensity is measured in terms of lumens per square foot (footcandles) or lumens per square meter (lux).
What does light intensity depend on?
amplitude According to the electromagnetic theory, the intensity of a wave is directly proportional to its amplitude, i.e., I ∝ A 2 . Since light is also an electromagnetic wave, the intensity of light will depend upon the amplitude of the wave.
What is light intensity in photosynthesis?
Light intensity is usually defined as the energy hitting an area over some time period. So in the case of a plant, a higher light intensity means more packets of light called “photons” are hitting the leaves.
How does the intensity of light change for a location depending on the season?
The inverse square law shows that when light travels twice the distance its area grows four times as large and the brightness decreases by four times. The rate a light grows in area and decreases in brightness is related to the distance it travels from another point squared.
What is solar variation and how does it vary?
Solar variability refers to the changes in the levels of solar radiation as well as in the number and size of sunspots with 11- year cyclic variation. So, it is likely to affect climate on time scales of minutes to millions of years. It is often believed that only slow variations can affect the climate.
What are the reasons for variation in solar radiation reaching the Earth than received at the outside of the atmosphere?
Solar radiation at the Earth's surface varies from the solar radiation incident on the Earth's atmosphere. Cloud cover, air pollution, latitude of a location, and the time of the year can all cause variations in solar radiance at the Earth's surface.
Is the sun more intense?
But many have wondered, is the sun getting stronger? It's a question News 8 wanted to VERIFY. According to Scripps Atmospheric Scientist Ray Weiss the answer is no, even though it feels that way. He says it's not that the sun is stronger, but rather the ozone layer is thinner meaning more UV rays are coming through.
What causes variation in day and night?
Rotation of the Earth causes night and day to alternate. Since we learned that the Earth's axis is tilted and hence the equator is not facing the Sun directly, different places on Earth would experience unequal length of days and nights—not exactly 12 hours of day and 12 hours of night all the time.
Why does the variation in the length of day and night goes on increasing towards the pole?
It is because the amount of solar energy,i.e.,the rays of the sun, gets on decreasing as it reaches the poles. The areas near the equator experience equal duration of day and night than the areas away from the equator.
How do you change the intensity of light?
Use dimmers that can control the brightness of the bulbs in the range of 5-99%, and the lamps, which can be switched on and off with a gradual onset, thereby saving bulb. With the dimmer in combination with wireless control, you can regulate the lighting even from the comfort of your sofa.
How can you change the intensity of light?
Light intensity can be altered by using clothes / shades, poly sheets, putting temp covers for few hrs. But one has to see the purpose and procedures simultaneously. the easiest way to change light intensity is shading using different materials.
How does light intensity and distance affect the rate of photosynthesis?
As light intensity increases (distance between lamp and plant decreases) the volume of oxygen (or the rate of bubble production) increases. This indicates that the rate of photosynthesis increases with light intensity.
How does light intensity affect the rate of photosynthesis experiment results?
An increase in light intensity will produce an increase in the rate of photosynthesis until a level of light intensity is reached (normally 38% 1) above which the rate does not increase because the light saturation point has been reached and another factor (CO2 concentration or temperature) is limiting.
How does variation in the Sun’s intensity cause global warming?
No. The Sun can influence Earth's climate, but it isn't responsible for the warming trend we've seen over recent decades. The Sun is a giver of life; it helps keep the planet warm enough for us to survive. We know subtle changes in Earth's orbit around the Sun are responsible for the comings and goings of the ice ages.
What is variations in solar activity?
Solar variability refers to the changes in the levels of solar radiation as well as in the number and size of sunspots with 11- year cyclic variation. So, it is likely to affect climate on time scales of minutes to millions of years. It is often believed that only slow variations can affect the climate.