What is the energy budget in relation to the sun and Earth?
The energy balance drives the weather and life on earth. Essentially 100% of the energy that fuels the earth comes from the sun. To maintain a constant global average temperature, all of the sun’s radiation that enters Earth’s atmosphere must eventually be sent back to space.
In what ways does the Earth balance out the incoming energy from the sun?
For the energy budget at Earth’s surface to balance, processes on the ground must get rid of the 48 percent of incoming solar energy that the ocean and land surfaces absorb. Energy leaves the surface through three processes: evaporation, convection, and emission of thermal infrared energy.
What is the incoming solar radiation received by the Earth?
About 23 percent of incoming solar energy is absorbed in the atmosphere by water vapor, dust, and ozone, and 48 percent passes through the atmosphere and is absorbed by the surface. Thus, about 71 percent of the total incoming solar energy is absorbed by the Earth system.
What is the solar energy budget?
Earth’s energy budget describes the balance between the radiant energy that reaches Earth from the sun and the energy that flows from Earth back out to space. Energy from the sun is mostly in the visible portion of the electromagnetic spectrum.
What is called albedo?
Albedo (al-bee-doh) is a measure of how much light that hits a surface is reflected without being absorbed. Something that appears white reflects most of the light that hits it and has a high albedo, while something that looks dark absorbs most of the light that hits it, indicating a low albedo.
What is albedo used for?
Albedo, fraction of light that is reflected by a body or surface. It is commonly used in astronomy to describe the reflective properties of planets, satellites, and asteroids. It is an important consideration in climatology since recent albedo decreases in the Arctic have increased heat absorption at the surface.
What has an albedo of 100?
Albedo is measured as a percentage. A perfectly black surface has an albedo of zero percent and a perfectly white surface has an albedo of 100 percent. The albedo of fresh snow is typically between 80 and 90 percent whereas the albedo of the ocean surface is less than 20 percent.
Is high albedo good?
Here on Earth, the albedo effect has a significant impact on our climate. The lower the albedo, the more radiation from the Sun that gets absorbed by the planet, and temperatures will rise. If the albedo is higher, and the Earth is more reflective, more of the radiation is returned to space, and the planet cools.
What things have high albedo?
Bright, reflective surfaces, such as fresh snow, have a high albedo; dark, absorptive surfaces, such as dense forest, have a low albedo.
Do oceans have high albedo?
Because much of the land surface and oceans are dark in color, they have a low albedo. They have very high albedo, as high as 0.8 or 0.9, and reflect most of the solar energy that gets to them, absorbing very little. The albedo of all these different surfaces combined is called the planetary albedo.
What causes albedo?
The water vapor causes cooling on the land surface, causes heating where it condenses, acts a strong greenhouse gas, and can increase albedo when it condenses into clouds.
Why does snow have high albedo?
The sea ice absorbs less solar energy and keeps the surface cooler. Snow has an even higher albedo than sea ice, and so thick sea ice covered with snow reflects as much as 90 percent of the incoming solar radiation.
Does vegetation have a high albedo?
The higher the albedo, the more the surface reflects light. Vegetation and water also have low albedos. Most of Sun’s radiation is in the shortwave (visible) spectrum. The Earth as a whole reflects about 30% of this radiation back into space (and absorbs the rest, which helps warm the planet).
Which albedo is lowest?
A low albedo refers to a surface which reflects a small amount of the incoming radiation and absorbs the rest of the radiation. This clearly indicates that all black surfaces have the lowest albedo. Fresh snow reflects approximately 95 percent of the sun’s rays so it has the highest albedo.
Which has higher albedo land or water?
Land and liquid water have relatively low albedos (10 to 40 %), while ice and snow have higher albedos, typically between 70 and 90%. Multiple factors and processes can change the albedo of a surface over time.
What is reflected sunlight called?
That’s because the white snow reflects the Sun’s radiation, while the darker earth absorbs it and heats up. Earth’s ability to reflect the Sun’s light, called albedo, is influenced by the color, type and texture of surfaces ranging from snow, vegetation and urban areas.
How do humans affect albedo?
Human-driven changes in land use and land cover such as deforestation, urbanization, and shifts in vegetation patterns also alter the climate, resulting in changes to the reflectivity of the Earth surface (albedo), emissions from burning forests, urban heat island effects and changes in the natural water cycle.
Does deforestation increase albedo?
Forests are darker in colour than grass or cropland so deforestation increases the reflectivity of the land surface (i.e., its albedo). An increase in surface albedo will exert a negative radiative effect, or cooling, on the climate8.
Does deforestation affect global warming?
Tropical forest trees, like all green plants, take in carbon dioxide and release oxygen during photosynthesis. And this is how deforestation and forest degradation contribute to global warming. According to the best current estimate, deforestation is responsible for about 10 percent of all global warming emissions.
Do trees have high albedo?
Because trees tend to have a low albedo, removing forests would tend to increase albedo and thereby could produce localized climate cooling. Cloud feedbacks further complicate the issue. Deciduous trees have an albedo value of about 0.15 to 0.18 while coniferous trees have a value of about 0.09 to 0.15.
How does global warming affect albedo?
Climate Change As the world warms the Earth’s albedo shifts. The amount of ice covering the planet is dropping as a result of increased temperatures from global warming. This causes a decrease in the area of white surfaces, leading to less energy to be reflected and more to be absorbed.
What happens if both daisies are darker respectively lighter than the ground?
Daisyworld is populated by two types of daisies, one darker and the other lighter than the bare ground. Conversely, an increase in the white daisy population will result in more radiation being reflected away, lowering the planet’s temperature.
Is the earth’s albedo decreasing?
Dark blue shows areas where Earth reflected the lowest percentage of shortwave solar radiation. In the May 6, 2005, issue of the journal Science, the CERES Science Team reported Earth’s shortwave albedo has been steadily declining since the Terra CERES instrument began making the measurement in February 2000.
What causes albedo to decrease?
When air temperatures increase and snow and ice melt, the reflectivity of the Earth’s surface decreases and, hence, solar radiation is retained. The increase in net radiation leads to increased temperatures and to more ice sheet decay, further lowering the albedo.
Why does earth’s albedo change daily?
Why does Earth’s albedo change daily? The Earth’s albedo changes on a daily basis depending on the amount and location of cloud cover over the sunlit side of the Earth. The albedo changes seasonally due to the amount of ice and snow (which are highly reflective to light) that is facing towards the Sun.
What is Earth’s average albedo?
about about 0.30