Heating of the earth|Grade 10 Geography|

Summary

In this video, we explore the Earth's heating processes, focusing on radiation, conduction, and convection. Radiation involves the emission of heat in the form of waves from the Sun to the Earth. Conduction transfers heat through direct contact, while convection involves vertical heat movement within fluids like air or water. The video also compares solar radiation (insolation) with terrestrial radiation from the Earth’s surface, highlighting their distinct characteristics and timing. Insulation primarily occurs during the day with short and long waves, whereas terrestrial radiation takes place at night with long waves. The video provides a clear understanding of these fundamental processes shaping the Earth's climate.

Takeaways

• 😀 Radiation is the emission of heat and energy in the form of waves, transferring energy from the Sun to the Earth.
• 😀 Incoming solar radiation, or insulation, refers to the radiant energy that moves towards Earth from the Sun, which is initially at 100% before being absorbed or reflected.
• 😀 51% of incoming solar radiation is absorbed by Earth's surface, including land, buildings, trees, and people.
• 😀 19% of solar radiation is absorbed by the atmosphere and clouds.
• 😀 6% of solar radiation is reflected by the atmosphere, while 20% is reflected by the clouds.
• 😀 4% of solar radiation is reflected from Earth's surface, resulting in 47% of energy remaining in the Earth's surface after reflection.
• 😀 Conduction is the transfer of heat through direct contact, like when a hot surface transfers heat to a cooler object touching it.
• 😀 Convection involves the vertical movement of heat in fluids (liquids or gases), where heat rises and cooler substances sink.
• 😀 Radiation, convection, and conduction are the primary processes involved in the transfer of heat on Earth, each with unique characteristics and functions.
• 😀 Insulation occurs during the day and involves both short and long waves of radiation from the Sun, while terrestrial radiation takes place at night and involves long waves released by the Earth.
• 😀 Terrestrial radiation is emitted by the Earth and its atmosphere, and occurs mainly at night, unlike insulation, which requires the presence of the Sun.

Q & A

What is the process of radiation in the context of Earth's heating?

Radiation is the emission of heat and energy in the form of waves from the Sun to the Earth. This heat is transferred through radiant energy, and the Earth's surface absorbs a significant portion of this energy.

How much of the incoming solar radiation is absorbed by the Earth's surface?

51% of the incoming solar radiation is absorbed by the Earth's surface, including the ground, trees, buildings, and other elements.

What is the difference between solar radiation (insolation) and terrestrial radiation?

Solar radiation (insolation) comes from the Sun and is emitted during the day, consisting of both long and short waves. Terrestrial radiation, on the other hand, is emitted by the Earth, mainly at night, and consists of long waves only.

What role do water vapor and carbon dioxide play in terrestrial radiation?

Water vapor and carbon dioxide are concentrated close to the Earth's surface, where they absorb and retain terrestrial radiation. This helps warm the air near the Earth's surface.

What happens to solar radiation once it reaches the Earth?

Once solar radiation reaches Earth, 51% is absorbed by the surface, 19% is absorbed by the atmosphere and clouds, 6% is reflected by the atmosphere, 20% is reflected by the clouds, and 4% is reflected by the surface.

How does convection transfer heat?

Convection is the transfer of heat through vertical movement in a fluid (liquid or gas). As air or water becomes heated, it rises, and cooler air or water moves downward, creating a circulation that distributes heat.

What is conduction, and how does it work in heating?

Conduction is the transfer of heat through direct contact. When a hot object touches a cooler one, heat is transferred from the hotter object to the cooler one, like when you touch a hot pan.

Why does solar radiation primarily occur during the day?

Solar radiation primarily occurs during the day because the Sun is present, emitting radiant energy in the form of waves. Without the Sun, radiation does not occur at night.

What percentage of the Earth's surface energy is reflected back into space?

A combined total of 30% of the incoming solar energy is reflected back into space, with 6% reflected by the atmosphere, 20% reflected by clouds, and 4% reflected by the Earth's surface.

How does terrestrial radiation contribute to the Earth's nighttime heating?

Terrestrial radiation contributes to nighttime heating by releasing heat in the form of long waves from the Earth's surface and atmosphere. This process helps maintain warmth near the Earth's surface after the Sun has set.