Related topics: magnetic field · earth · sun · nasa

Lunar soil has the potential to generate oxygen and fuel

Soil on the moon contains active compounds that can convert carbon dioxide into oxygen and fuels, scientists in China report May 5 in the journal Joule. They are now exploring whether lunar resources can be used to facilitate ...

Active galaxy RXJ0134.2-4258 investigated in detail

Using XMM-Newton and NuSTAR satellites, astronomers have conducted a comprehensive, long-term multiwavelength study of an active galaxy known as RXJ0134.2-4258. Results of the observational campaign, published March 25 on ...

Researchers discover source of super-fast electron rain

UCLA scientists have discovered a new source of super-fast, energetic electrons raining down on Earth, a phenomenon that contributes to the colorful aurora borealis but also poses hazards to satellites, spacecraft and astronauts.

B2 1420+32 is a changing-look blazar, study finds

An international team of astronomers has performed multi-wavelength photometric and spectroscopic observations of a blazar known as B2 1420+32. The observational campaign found that the object exhibits a large scale spectral ...

Study shows our sun is less active than similar stars

By cosmic standards the sun is extraordinarily monotonous. This is the result of a study presented by researchers from the Max Planck Institute for Solar System Research in the upcoming issue of Science. For the first time, ...

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Solar variation

Solar variations are changes in the amount of solar radiation emitted by the Sun. There are periodic components to these variations, the principal one being the 11-year solar cycle (or sunspot cycle), as well as aperiodic fluctuations. Solar activity has been measured via satellites during recent decades and through 'proxy' variables in prior times. Climate scientists are interested in understanding what, if any, effect variations in solar activity have on the Earth. Effects on the earth caused by solar activity are called "solar forcing".

The variations in total solar irradiance remained at or below the threshold of detectability until the satellite era, although the small fraction in ultra-violet wavelengths varies by a few percent. Total solar output is now measured to vary (over the last three 11-year sunspot cycles) by approximately 0.1% or about 1.3 W/m² peak-to-trough during the 11 year sunspot cycle. The amount of solar radiation received at the outer surface of Earth's atmosphere averages 1,366 watts per square meter (W/m²). There are no direct measurements of the longer-term variation and interpretations of proxy measures of variations differ. On the low side North et al. report results suggesting ~ 0.1% variation over the last 2,000 years. Others suggest the change has been ~ 0.2% increase in solar irradiance just since the 17th century. The combination of solar variation and volcanic effects are likely to have contributed to climate change, for example during the Maunder Minimum. Apart from solar brightness variations, more subtle solar magnetic activity influences on climate from cosmic rays or the Sun's ultraviolet radiation cannot be excluded although confirmation is not at hand since physical models for such effects are still too poorly developed.

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