Explosive solar activity imaged
3 Aug 2012 by Evoluted New Media
New images of an upward surge of the Sun’s gases into a coronal loop have helped scientists move closer towards understanding the origin of space storms.
Meanwhile the UK Government Office for Science and the US National Oceanic & Atmospheric Administration (NOAA) have strengthened their agreement to protect infrastructure from space weather.
International researchers have visualised the movement of gases in coronal loops – solar structures rooted at both ends and extending out from active regions in the Sun – using images from the Hinode spacecraft. Active regions act as cradles for explosive energy releases like solar flares and coronal mass ejections (CMEs).
“Active regions are now occurring frequently across the Sun. We have a really great opportunity to study them with solar spacecraft, such as Hinode and the Solar Dynamic Observatory (SDO),” said Dr Helen Mason from the University of Cambridge. “Probing the heating of the Sun’s active region loops can help us to better understand the physical mechanisms for more energetic events which can impinge the Earth’s environment.”
The findings – published in Astrophysical Journal Letters – show plasma upflows travel at 20km/s and result from impulsive heating close to the footpoint of the loop. Researchers suggest gas movement is caused by chromospheric evaporation where small scale impulsive heating can result in heating of the solar active regions, but on larger scales can lead to CMEs or solar flares.
Plasma flow shows up as blueshift in diagnostic images taken by the extreme ultraviolet imaging spectrometer (EIS) – spectral lines act like fingerprints which identify elements and ions within the loops while shifts in the position of the lines provide information on the motion of the plasma.
The findings will help scientists understand how solar structures are heated and maintained in the upper solar atmosphere and how extreme solar activity might lead to space storms which interfere with satellites and power grids.
Meanwhile the existing agreement between the Government Office for Science and the NOAA regarding space weather has been strengthened.
“Space weather is a global challenge requiring coordinated global preparedness. We recognise space weather as a significant natural hazard risk with economic and societal impacts on key infrastructures and technologies,” the statement said.
“Space weather is a global challenge that requires a coordinated response,” said Sir John Beddington, UK Government Chief Scientific Officer. “The inclusion of space weather in the UK’s National Risk Register is evidence that we are already taking it seriously.”
