Table of Contents
In what areas of the world is there a net radiation deficit?
As the September equinox approaches, a zone of positive net radiation is nearly centered over the equator, and energy deficits lie over the poles. As the season changes into winter, the net radiation becomes negative across much of the Northern Hemisphere and positive in the Southern Hemisphere.
Where is net radiation generally highest?
For all surfaces, the net radiation is greatest when the sun is shining between clouds and is larger under an overcast sky than it is when the sun is near the horizon.
What is the Earth’s net radiation budget?
Of the ~340 W/m2 of solar radiation received by the Earth, an average of ~77 W/m2 is reflected back to space by clouds and the atmosphere and ~23 W/m2 is reflected by the surface albedo, leaving ~240 W/m2 of solar energy input to the Earth’s energy budget. This amount is called the absorbed solar radiation (ASR).
What affects net radiation budget?
Some places absorb more energy than reflect, while other places on Earth reflect more energy than absorb. Factors that affect the net radiation of a place include albedo, latitude and Sun angle, atmospheric conditions (like clouds and dust), and the time of year.
Why is net radiation negative at night?
At night, the net radiation is usually a negative value as there is no incoming solar radiation and net long-wave is dominated by the outgoing terrestrial long-wave flux. The net radiation is zero when the incoming and outgoing components are in perfect balance, which doesn’t occur too often.
Where is longwave radiation most negative?
Surface Longwave Radiation Budget The surface downward longwave radiation is dominated by the radiation from a shallow layer close to the surface of the earth. The atmosphere above 500 meters from the surface only accounts for 16–20% of the total surface downward longwave radiation.
What time of day is net radiation positive?
As net radiation become positive, the surface warms quickly and transfers heat to the air above. Air temperature rises sharply in the morning hours and continues to rise after the noon peak of net radiation.
What radiation reaches the Earth’s surface?
Most of the solar radiation that reaches Earth is made up of visible and infrared light. Only a small amount of ultraviolet radiation reaches the surface.
Why is longwave radiation negative?
Which two gases are the most effective at absorbing longwave radiation?
Which two gases are the most effective at absorbing longwave radiation? Greenhouse gases in the atmosphere (such as water vapor and carbon dioxide) absorb most of the Earth’s emitted longwave infrared radiation, which heats the lower atmosphere.
How is net radiation determined?
Net radiation is the sum of short-wave radiation and long-wave radiation. It can be determined either by direct measurement or by calculation. For the direct measurement, net radiometer is usually used after calibration. The calibration allows the definition of a parameter termed as “net radiometer sensitivity”.