Devdiscourse News Desk 29 Aug 2018, 01:18 PM
New research by US scientists has detected that the Sun is emitting a higher than expected amount of high-energy light consisting of gamma rays. But the most unusual thing is that the rays with the highest energy appear when the star is at its least active point, according to the study, which is published in the journal Physical Review Letters.
The work is the first investigation that has examined gamma rays over most of the solar cycle, a period of about 11 years during which the activity of the star increases and decreases.
The group of scientists, led by astrophysicist Tim Linden, analyzed data that NASA’s Fermi Gamma-ray space telescope collected between August 2008 and November 2017. The observations included a period of low solar activity in 2008 and 2009, a period of greatest activity in 2013 and a reduction in activity to the minimum before the start of a new cycle in 2018.
The team tracked the number of solar gamma rays emitted every second, as well as their energies and where they came from.
The team reported that during the years analyzed, the number of gamma rays emitted was so high (more than 50,000 million electron volts, or GeV) that all predictions were exceeded. However, interestingly, rays with energies above 100 GeV appeared only during the minimum solar activity.
Even rarer is that the Sun seems to emit gamma rays from different parts of its surface at different times of the cycle. During the solar minimum, gamma rays came mainly from an area near the equator, while during solar maximum, when the level of the star’s activity was high, the rays were grouped near the poles. [Emphasis added]
All this is much rarer than predicted, said the astrophysicist John Beacom of Ohio State University in Columbus.
The scientist stressed that this unusual activity could mean that the Sun’s magnetic fields are much more powerful, much more variable and have a much stranger shape than we expected.
In addition, the expert stressed that high-energy gamma rays can offer new possibilities for the study of magnetic fields in the upper layer of the solar surface, called the photosphere.
Fields cannot be seen with a telescope, says Beacom. “But cosmic rays that travel there and the gamma rays they send are messengers of the terrible conditions that exist in the photosphere, said the scientist.
My question is what does this mean for us on the planet earth? See the highlighted text. If during the minimum the gamma rays come from near the equator, we should detect more on earth as opposed to those emitted at the poles. When a gamma ray strikes the top of the atmosphere, it initiates a cascade of particles, which in turn produces a flash of blue light. How could an increase in gamma rays impact our climate during solar minimum? Cosmic rays produce the same Compton scattering and are thought to increase cloud cover. Thoughts?
I’ve often wondered if the sun does things that we’ve never seen over the short time we’ve observed it, and if those things might have strong effects on our climate. Changes like cloud cover or even circulation patterns.
Agree, we need more information on the interaction between the sun and earth. We may be blinded by the light and heat, as there seems to be bigger conections we are missing.
If it was as straight forward as the climate scientists say, they’d be able to roughly plot the past, but can’t. We’d know if they had because they’d keep telling us. The pause, the wiggly jet stream, the ocean phases, etc must have explanations but the scientsts are just guessing and can’t predict their behaviour. Fair enough, their claim is that they can’t predict short term variations but they can’t do long term ones either, so something more than Earthly processes are probably going on.
There are studies into the relationship between ‘short term’ solar impacts and surface climate.
Impacts from CME’s and aggressive solar wind cause expansion and contraction of the upper atmosphere, this pushes and pulls on the thermal and pressure profiles in the atmosphere, shifting and changing the jet stream path and speed and altering the behaviour of surface level weather patterns.
Add in the effects of cosmic rays et al., and you have some appreciation of the variability we see.
There are also indications that the so-called ‘J-Hook’ temperature rise occurred as a result of the shift from manual sea temp readings, using hand held thermometers, under difficult conditions, in whole degrees, to remote digital readouts with two or more decimal places. This took place slowly over the period 1980-2000 and would give a logical argument for the observed rise then ‘pause’ when it was completed. But this is controversial.
https://howtheatmosphereworks.wordpress.com/solar-activity-and-surface-climate/ may interest.
Reblogged this on Tallbloke's Talkshop and commented:
Interesting. Another article reporting the solar gamma ray ‘mystery’ can be found here.
Thanks for the link to the Scientific American article. This is going to be an interesting scientific detective story.