Why is insolation greatest when the sun is overhead?
Insolation depends on the angle of the Sun above the horizon. It is greatest when the Sun is directly overhead, and it decreases when the Sun is low in the sky, since the same amount of solar energy is spread out over a greater area of ground surface (Figure 2.7).
What is the effect of atmosphere?
Very little of the radiation emitted by Earth’s surface passes directly through the atmosphere. Most of it is absorbed by clouds, carbon dioxide, and water vapour and is then reemitted in all directions. The atmosphere thus acts as a radiative blanket over Earth’s surface, hindering the loss of heat to space.
How does the atmosphere affect human life?
Not only does it contain the oxygen we need to live, but it also protects us from harmful ultraviolet solar radiation. It creates the pressure without which liquid water couldn’t exist on our planet’s surface. And it warms our planet and keeps temperatures habitable for our living Earth.
How does temperature change affect the atmosphere?
Higher temperatures mean that heat waves are likely to happen more often and last longer, too. Warmer temperatures can also lead to a chain reaction of other changes around the world. That’s because increasing air temperature also affects the oceans, weather patterns, snow and ice, and plants and animals.
How is the atmosphere of the Earth changing?
Variations in the intensity of solar radiation influence the energy balance, chemistry, and dynamics of the atmosphere, as do fluctuations in the intensity of the solar wind and of cosmic rays from space. Volcanic eruptions inject dust, ash, and a variety of chemical compounds into the atmosphere.
Is it hot or cold in the atmosphere?
The reason it is “cold” in the upper atmosphere is actually because of a lower air density. Remember that our concept of “temperature” as measured by a thermometer is actually the energy of the collisions between atoms.
How hot is the upper atmosphere?
The exact temperature of the thermosphere can vary substantially, but the average temperature above 180 miles (300 km) is about 800 degrees Fahrenheit (427 degrees Celsius) at solar minimum and 1,700 degrees Fahrenheit (927 degrees Celsius) at solar maximum.
Why is it cold outside the Earth’s atmosphere?
The reason outer space is so cold is because cold is what you get when there is no source of heat nearby. Objects in space cannot cool off by thermal conduction or convection, but they can cool off by radiating infrared light. All objects do this, and they radiate more the hotter they get.
How cold is in space?
around 2.7 kelvin