Arctic ocean expedition advances climate modeling

As the climate warms and Arctic sea ice retreats, more research vessels and commercial ships are sailing into the Arctic Ocean, but the accuracy and sensitivity of regional weather and marine forecasts for these hazardous ...

How does incident solar radiation affect urban canyons?

Jihui Yuan (Assistant Professor, Department of Architecture and Civil Engineering, Toyohashi University of Technology) proposed a numerical bead model to predict the upward-to-downward reflection ratio of glass bead retro-reflective ...

The largest-ever catalog of gravitational waves released

One of humankind's greatest achievements was made on 14th Sept 2015 when the first direct detection of a gravitational wave event was made using the aLIGO observatories in Washington State and Louisana in the U.S.

SpaceX to send TU Dresden satellite into space

TU Dresden's SOMP2b satellite will be lifted into orbit by SpaceX on January 22, 2021. It will be used to investigate new nanomaterials under the extreme conditions of space, to test systems for converting the sun's heat ...

Energy from solar wind favors the north

Using information from ESA's Swarm satellite constellation, scientists have made a discovery about how energy generated by electrically-charged particles in the solar wind flows into Earth's atmosphere—surprisingly, more ...

Aluminum alloy research could benefit manned space missions

The MIAMI-2—Microscopes and Ion Accelerators for Materials Investigations—facility has helped Dr. Matheus Tunes investigate a new alloy that will harden aluminum without increasing its weight significantly.

Mars is getting a new robotic meteorologist

Mars is about to get a new stream of weather reports, once NASA's Perseverance rover touches down on Feb. 18, 2021. As it scours Jezero Crater for signs of ancient microbial life, Perseverance will collect the first planetary ...

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Sunlight, in the broad sense, is the total spectrum of the electromagnetic radiation given off by the Sun. On Earth, sunlight is filtered through the atmosphere, and the solar radiation is obvious as daylight when the Sun is above the horizon. Near the poles in summer, the days are longer and the nights are shorter or non-existent. In the winter at the poles the nights are longer and for some periods of time, sunlight may not occur at all. When the direct radiation is not blocked by clouds, it is experienced as sunshine, a combination of bright light and heat. Radiant heat directly produced by the radiation of the sun is different from the increase in atmospheric temperature due to the radiative heating of the atmosphere by the sun's radiation. Sunlight may be recorded using a sunshine recorder, pyranometer or pyrheliometer. Sunlight takes about 8.3 minutes to reach the Earth. The World Meteorological Organization defines sunshine as direct irradiance from the Sun measured on the ground of at least 120 watts per square metre.

Direct sunlight has a luminous efficacy of about 93 lumens per watt of radiant flux, which includes infrared, visible, and ultra-violet light. Bright sunlight provides luminance of approximately 100,000 candela per square meter at the Earth's surface.

Sunlight is a key factor in photosynthesis, a process crucially important for life on Earth.

This text uses material from Wikipedia, licensed under CC BY-SA