اس

**اُس** يا **[[سج جي روشني]]** (Sunlight) برقي مقناطيسي تابڪاري جو حصو آهي جيڪي سج جي يعني شمسي تابڪاري ذريعي خارج ٿئي ٿي ۽ ڌرتي طرفان حاصل ڪئي ويندي آهي، خاص طور تي انساني اک کي محسوس ٿيندڙ نظر ايندڙ روشني سان گڏ پوشيده انفراريڊ (عام طور تي انسانن پاران گرمي جي طور تي سمجهيو ويندو آهي) ۽ الٽراوائليٽ (جنهن جا جسماني اثر ٿي سگهن ٿا جهڙوڪ ڏسڻ ۾ خرابي) روشنيون. بهرحال، آمريڪي موسمياتي سوسائٽي جي مطابق، "متضاد روايتون آهن ته ڇا هن ٽنهي (ڏسڻ قابل، انفرا ريڊ ۽ الٽراوائليٽ) کي روشني طور حوالو ڏنو وڃي ٿو، يا ڇا اهو اصطلاح صرف اسپيڪٽرم جي نظر ايندڙ حصي تي لاڳو ڪيو وڃي". ڌرتيءَ تي پهچڻ تي، سج جي روشني زمين جي وايومنڊل ۾ ڏينهن جي روشني جي طور تي پکڙيل ۽ فلٽر ڪئي ويندي آهي جڏهن سج افق کان مٿي هوندو آهي. جڏهن سڌي شمسي تابڪاري ڪڪرن پاران بلاڪ نه ڪئي ويندي آهي، ته ان کي سج جي روشني طور محسوس ڪيو ويندو آهي، روشن روشني ۽ تابڪاري گرمي (ماحول) جو ميلاپ. جڏهن ڪڪرن طرفان بلاڪ ڪيو ويندو آهي يا ٻين شين مان عڪاسي ڪيو ويندو آهي، سج جي روشني ڦهلجي ويندي آهي. ذريعن جو اندازو آهي ته 24 ڪلاڪن جي ڏينهن دوران عالمي سراسري 164 واٽ کان 340 واٽ في چورس ميٽر جي وچ ۾ آهي؛ هي انگ ناسا پاران ڌرتيء جي سراسري ڪل شمسي شعاعن جو چوٿون حصو هجڻ جو اندازو لڳايو ويو آهي.

سج، جيئن بين الاقوامي خلائي اسٽيشن کي نظر ڪندي، زمين جي گهٽ مدار مان ڏٺو وڃي ٿو. هتان سج جي روشني هيٺين ڌرتي جي وايو منڊل پاران فلٽر نه ڪيل آهي. جيڪو هن جي اسپيڪٽرم جو گهڻو حصو بلاڪ ڪري ٿو.

سج مان نڪرندڙ روشنيءَ کي چيو ويندو آھي. اس انسانن، جانورن، ٻوٽن ۽ ٻين جاندارن جي جياپي لاءِ تمام اھم آھي. اس نه رڳو روشنيءَ جو ذريعو آھي پر اھا جاندارن کي ضروري سگهه ۽ ڪيميائي تبديليون ڪرڻ ۾ پڻ مدد ڪري ٿي.

**Sunlight** is the portion of the electromagnetic radiation which is emitted by the Sun (i.e. solar radiation) and received by the Earth, in particular the visible light perceptible to the human eye as well as invisible infrared (typically perceived by humans as warmth) and ultraviolet (which can have physiological effects such as sunburn) lights. However, according to the American Meteorological Society, there are "conflicting conventions as to whether all three [...] are referred to as light, or whether that term should only be applied to the visible portion of the spectrum". Upon reaching the Earth, sunlight is scattered and filtered through the Earth's atmosphere as daylight when the Sun is above the horizon. When direct solar radiation is not blocked by clouds, it is experienced as **sunshine**, a combination of bright light and radiant heat (atmospheric). When blocked by clouds or reflected off other objects, sunlight is diffused. Sources estimate a global average of between 164 watts to 340 watts per square meter over a 24-hour day; this figure is estimated by NASA to be about a quarter of Earth's average total solar irradiance.

Sunlight takes about 8.3&nbsp;minutes to reach Earth from the surface of the Sun. A photon starting at the center of the Sun and changing direction every time it encounters a charged particle would take between 10,000 and 170,000 years to get to the surface. Sunlight is a key factor in photosynthesis, the process used by plants and other autotrophic organisms to convert light energy, normally from the Sun, into chemical energy that can be used to synthesize carbohydrates and fuel the organisms' activities. The ultraviolet radiation in sunlight has both positive and negative health effects, as it is both a requisite for vitamin D<sub>3</sub> synthesis and a mutagen.

*[[Daylighting (architecture)|Daylighting]]* is the natural lighting of interior spaces by admitting sunlight.
*[[Solar irradiance]]* is the rate of solar energy received by a unit area from sunlight.

## حوالا

## ٻاهريان ڳنڍڻا
* 
* Solar radiation – Encyclopedia of Earth

* Total Solar Irradiance (TSI) Daily mean data at the website of the National Geophysical Data Center
* Construction of a Composite Total Solar Irradiance (TSI) Time Series from 1978 to present by World Radiation Center, Physikalisch-Meteorologisches Observatorium Davos (pmod wrc)
* A Comparison of Methods for Providing Solar Radiation Data to Crop Models and Decision Support Systems, Rivington et al.
* Evaluation of three model estimations of solar radiation at 24 UK stations, Rivington et al.
* High resolution spectrum of solar radiation from Observatoire de Paris
* Measuring Solar Radiation : A lesson plan from the National Science Digital Library.
* Websurf astronomical information: Online tools for calculating Rising and setting times of Sun, Moon or planet, Azimuth of Sun, Moon or planet at rising and setting, Altitude and azimuth of Sun, Moon or planet for a given date or range of dates, and more.
* An Excel workbook with a solar position and solar radiation time-series calculator; by Greg Pelletier
* ASTM Standard for solar spectrum at ground level in the US (latitude ~37 degrees).
* Detailed spectrum of the Sun at Astronomy Picture of the Day.

زمرو:سج
زمرو:توانائي
زمرو:تابڪاري
زمرو:شمسي توانائي
زمرو:فضائي تابڪاري
زمرو:روشني جا ذريعا