However, it can also be harmful to human health, for example, due to its effects on our skin, and these effects have become more dangerous in recent years due to the greenhouse effect , which also influences the rising temperatures on our planet.
Read on to learn about the different types of radiation and how this phenomenon is produced. Solar radiation is the energy emitted by the Sun, which is sent in all directions through space as electromagnetic waves. Emitted by the surface of the Sun, this energy influences atmospheric and climatological processes. It is also, directly and indirectly, responsible for common phenomena, such as plant photosynthesis, keeping the planet at a temperature compatible with life and wind formation, which is essential for generating wind power.
The Sun emits energy in the form of short-wave radiation, which is weakened in the atmosphere by the presence of clouds and absorbed by gas molecules or suspended particles. After passing through the atmosphere, solar radiation reaches the oceanic and continental land surface and is reflected or absorbed. Finally, the surface returns it to outer space in the form of long-wave radiation. Solar radiation is measured on a horizontal surface by means of a radiation sensor or pyranometer, which is placed in a south-facing, shadow-free location.
Depending on the form in which it reaches the Earth:. Depending on the types of light:. One of the ways we have to measure the negative consequences of this type of radiation on people is the global solar UV index UVI. This index ranges from one to eleven and the higher the index, the greater the likelihood of skin and eye damage. The UV index and basic photoprotection recommendations.
In addition, warm water can not hold as much dissolved oxygen as cold water. This means that in warmer water, less dissolved oxygen is available for aquatic organisms Too much infrared light can also cause the enzymes used in photosynthesis to denature, which can slow or halt the photosynthetic process On the other side of the spectrum, radiation can be limited by cloudy days, shade sources or low sun angles.
If radiation from the sun is lower than usual for an extended period of time, photosynthetic production can decrease or be stopped completely.
Without sunlight, phytoplankton and plants will consume oxygen instead of producing it. These conditions can cause dissolved oxygen levels in the water to plummet, potentially causing a fish kill As in water, terrestrial radiation levels can be limited by cloudy weather This is particularly important to plants, as the photosynthetic process and plant physiology in general are dependent on sunlight. Stomata are pores found on the outer layer of plant leaves. They open in the presence of sunlight and allow water, carbon dioxide, and oxygen to enter the plant These molecules are then used to produce glucose through photosynthesis.
On cold, sunless days, stomata close because not enough energy from the sun is being received to continue photosynthesis Too much intense sunlight can also halt the production of photosynthesis, as stomata will close on sunny, hot and dry days to prevent water loss Sunlight can affect more than the opening and closing of plant stomata.
While some plants have specialized proteins that protect them from sunburn, others do not, and intense solar radiation can damage their leaves Plants that are not adapted to full or intense sunlight, such as hostas or rhododendrons, can develop heat stress.
Many plants, including shade plants, are susceptible to leaf scorch, where parts of the plant die due to excessive water loss through transpiration In addition to slowing or halting photosynthesis, heat stress and leaf scorch can make plants more susceptible to disease or insect infestations. How much light does the sun produce? This is a complex question to answer as there are different ways to consider and measure light.
There is radiance projected power and visible light, which can be measured as luminance brightness or illuminance incident light. Luminance and illuminance apply only to the wavelengths in the visible light band Sunlight is usually defined in radiance units, as only half of the solar radiation that reaches Earth is visible light, but all of the radiation provides energy.
Radiant energy can be measured in joules, though it is more commonly measured as radiant flux, or radiant power, which is expressed as energy over time. The sun emits ,,,,,,,, watts 3. For comparison, the average incandescent light bulb consumes watts. This energy is projected out from the sun in a sphere, where some will fall on Earth.
The energy that reaches Earth is measured as solar irradiance energy per second over a square meter. What does that mean in terms of visible light? Luminance and illuminance attempt to define the brightness and the light projected from a given source.
Lumens can only be measured over the photosynthetically active radiation band, or the range of visible light. In direct sunlight, when the sun is at its zenith directly overhead , measured lux could be as high as , On most sunny days out of direct light , illuminance is usually 10,, lux. On an overcast day, incident light may only reach lux, and at twilight it may be 10 lux The greater the angle of the sun, the lower the lux will be, as the lumens are spread out over a greater area.
Illuminance is important to consider when evaluating photosynthetically active radiation. The first barrier is the atmosphere. Ozone absorbs ultraviolet radiation, while carbon dioxide and water vapor can absorb infrared radiation Of the radiation that reaches the surface, approximately half is visible light and half is infrared light 1.
These reflection and absorption percentages can vary due to cloud cover and sun angle. Once the light reaches the surface of the water, reflection and scattering can occur. Reflection occurs when solar radiation simply bounces off the water 1. Longer wavelengths are reflected slightly more than shorter wavelengths Scattering is the deflection of light by molecules in the water.
Different materials, including dissolved and suspended solids, as well as organisms in the water, cause light to scatter in different directions 1.
The amount of light that scatters is dependent on the clarity of the water. The ocean is split into three zones based on light. The first zone, the euphotic or sunlight zone, is where sunlight penetrates.
Phytoplankton live in the euphotic zone because there is enough light for photosynthesis. This zone extends to about ft below the ocean surface. The next zone is called the dysphotic twilight zone. Some light is able to reach this depth, but it is not enough for photosynthesis to occur Sunlight cannot reach this zone, and its only light comes from bioluminescent organisms 2.
The depth that light penetrates in freshwater is dependent on water clarity. In waters with a high level of turbidity, or suspended solids, light will not reach as far as clear bodies of water. These suspended particles can both absorb and scatter light 1. In most rivers and streams, light will reach the riverbed, and photosynthesis can occur throughout the water column.
However, in particularly deep, algae-covered or turbid lakes, light may not be able to reach certain depths. Like the ocean, deep lakes are split into three zones.
The first zone is called the littoral zone. This zone is close to the shore and sunlight reaches all the way to the bottom. Aquatic plants in the littoral zone can grow on the lake bed and still receive enough light for photosynthesis The next zone is known as the limnetic zone and is the surface layer of open water.
Photosynthesis can occur in this zone as it is penetrated by light. The depth of the limnetic zone depends on the turbidity of the water.
In more turbid water, the limnetic zone will be shallower Below the limnetic zone is the profundal zone. This is the benthic bottom layer of a deep lake.
Sunlight cannot reach this zone, so photosynthesis will not occur. Instead, organisms that permanently reside in the profundal zone such as bacteria rely on falling organic matter from higher zones The amount of light absorbed in a body of water can be greatly affected by ice and snow cover.
However, if the ice is stained or cloudy, the percentage can drop dramatically. Opaque ice and heavy snow can drop the percentage of light transmission to nearly zero. If a body of water is covered in ice and snow for a long period of time, its entire metabolism can be stunted. New Word List Word List. Save This Word! See synonyms for solar radiation on Thesaurus. We could talk until we're blue in the face about this quiz on words for the color "blue," but we think you should take the quiz and find out if you're a whiz at these colorful terms.
Words nearby solar radiation solar panel , solar photovoltaic cells , solar plexus , solar pond , solar power , solar radiation , solar radius , solar sail , solar ship , solar still , solar system. Words related to solar radiation solar power , insolation. When the sun's rays are vertical, the Earth's surface gets all the energy possible. The more slanted the sun's rays are, the longer they travel through the atmosphere, becoming more scattered and diffuse. Because the Earth is round, the frigid polar regions never get a high sun, and because of the tilted axis of rotation, these areas receive no sun at all during part of the year.
The Earth revolves around the sun in an elliptical orbit and is closer to the sun during part of the year. When the sun is nearer the Earth, the Earth's surface receives a little more solar energy.
The Earth is nearer the sun when it is summer in the southern hemisphere and winter in the northern hemisphere. However, the presence of vast oceans moderates the hotter summers and colder winters one would expect to see in the southern hemisphere as a result of this difference. The Tilting results in longer days in the northern hemisphere from the spring vernal equinox to the fall autumnal equinox and longer days in the southern hemisphere during the other 6 months.
Days and nights are both exactly 12 hours long on the equinoxes, which occur each year on or around March 23 and September
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