![dark spots on the photosphere are known as dark spots on the photosphere are known as](https://img.haikudeck.com/mg/7A0EDADF-621D-41C5-8C6C-44CEFF4B6AA6.jpg)
In addition, flares often disturb the Earth’s atmosphere electrically, thus interfering with radio transmissions. Sunspot and solar flare frequency are strongly related. Large flares release 10^25 Joules, or about the energy of a few million volcanic eruptions on the Earth. During the eruption, flares rise thousands of kilometers above the chromosphere, and the plasma temperatures quickly soar to 20 million degrees. Sunspot activity generally follows an 11-year cycle, called the “sunspot cycle.” A solar flare is a violent eruption of plasma from the chromosphere of the Sun that is whipped up by intense magnetic activity. Sunspots range from Earth-size “pimples” to swollen scars halfway across the surface. The dark center of the sunspot is called the umbra, and it is surrounded by a dim filamentary area called the penumbra. 5 What do we call the bubbles that appear on the photosphere The dark patches. The knot causes the temperature to fall to around 1000 K in the sunspot region, which darkens the photosphere. This level is what we see as the glowing surface of the Sun - the photosphere. Strong, dense magnetic fields generated by circulating plasma sometimes become entangled and surge through the photosphere, creating the sunspot. Priyanka is a Guest Lecturer of Geography at New Alipore College, Kolkata.A sunspot is a cooler, and therefore darker, region of the Sun’s photosphere caused by a solar magnetic disturbance. The incoming short wave solar radiation have to pass through a mean sun-earth distance of 149.5 million kilometers and the earth’s atmosphere and hence some portion of solar energy lost through the process of reflection, diffusion, absorption, scattering etc.It is believed that the energy radiated from the sun increases when the number of sunspots increases and consequently the amount of insolation received at the earth’s surface also increases.These dark areas are cool areas because they are characterized by 15000 c less temperature then the chromospheres which surrounded them.Sunspots defined as dark areas within photosphere of the sun and surrounded by chromospheres, are created in the solar surface.While at the time of aphelion (July 4), farthest from the sun, receive minimum insolation.The earth at the time of perihelion (January 3), nearest to the sun, receive maximum insolation.If all other conditions are favourable and equal then longer duration of sunshine and shorter duration of night enable the ground surface to receive larger amount of insolation.thus the oblique rays have to travels larger distances than the vertical rays. Oblique rays have to pass through thicker portion of the atmosphere than the vertical rays.Oblique rays are spread over larger area of the earth’s surface and hence the amount of energy received per unit area decreases.Vertical rays are spread over minimum area of the earth’s surface and they heat the minimum possible area and thus the energy received per unit area increases.As the angle of sun’s ray decrease poleward, the amount of insolation received also decreases in that direction.On an average, the amount of insolation received at the earth’s surface decreases from equator towards the poles but there is temporal variation of insolation received at different latitudes at different times of the year.įACTORS AFFECTING THE DISTRIBUTION OF INSOLATION Fourth spectrum of the electromagnetic radiation waves consists of long waves including microwaves, radar waves and radio waves. Third spectrum of the electromagnetic radiation waves is called as infrared spectrum which consists of infrared waves of the wavelengths ranging from 0.7 micron to 300 microns.ĭ. The second spectrum of the electromagnetic radiation waves is also called as the spectrum of visible light.Ĭ. The electromagnetic radiation emitted from the outer surface of the sun consists of four spectra of radiation waves :Ī.The first spectrum of the electromagnetic waves includes gamma rays, hard X-rays, soft X-rays and ultra violet rays are called short waves.ī. The surface temperature of the sun is 60000 K.Within photosphere there are cool and dark spots, known as sunspots and hotspots which are collectively known as Faculae.The photosphere consists of 90 percent hydrogen and 10 percent helium.The bright outer surface of the sun is called Photosphere because of the dominance of photons.The sun is supposed to have been formed of four major zones namely core, Photosphere, Chromospheres and Corona.It is measured by the amount of solar energy received per square centimetre per minute. The radiant energy received from the sun, transmitted in a form analogous to shortwave (1/250 - 1/6700 mm in length), and travelling at the rate of 186000 miles a second is called solar radiation or Insolation.