Saturday, June 10, 2023

The Parker Solar Probe may have spotted the origin of high-speed solar winds

We still know very little about the sun and how the sun impacts the climate on earth! 

What if the sun is actually the main reason why earth climate changes over the decades, centuries, and thousands of years? I don't think the energy output of the sun is constant over the ages! If I am not mistaken, we have so far only identified the sun spot cycles! What about other periodic changes?


"... The streams appear to be guided by magnetic fields tracing back to two relatively cool regions of the sun’s atmosphere known as coronal holes, researchers report June 7 in Nature. ...
The solar wind — the steady stream of charged particles flowing from the sun — has two distinct speeds, dubbed as “slow” and “fast.” Until now, it wasn’t clear what was speeding the fast solar wind along. ...
Getting a handle on processes like the origin of the fast solar wind is important for practical reasons ...“We also believe that magnetic reconnection is responsible for solar flares and is involved in the release of coronal mass ejections, which have a major impact in space weather.” Solar flares and the space weather they create have led to electrical grid disruptions on Earth and interrupted radio communications, and they may threaten astronauts ...
The findings are also an important clue in the enduring mystery of why the sun’s atmosphere is millions of degrees Celsius hotter than its surface ..."

From the abstract:
"The fast solar wind that fills the heliosphere originates from deep within regions of open magnetic field on the Sun called ‘coronal holes’. The energy source responsible for accelerating the plasma is widely debated; however, there is evidence that it is ultimately magnetic in nature, with candidate mechanisms including wave heating and interchange reconnection. The coronal magnetic field near the solar surface is structured on scales associated with ‘supergranulation’ convection cells, whereby descending flows create intense fields. The energy density in these ‘network’ magnetic field bundles is a candidate energy source for the wind. Here we report measurements of fast solar wind streams from the Parker Solar Probe (PSP) spacecraft that provide strong evidence for the interchange reconnection mechanism. We show that the supergranulation structure at the coronal base remains imprinted in the near-Sun solar wind, resulting in asymmetric patches of magnetic ‘switchbacks’ and bursty wind streams with power-law-like energetic ion spectra to beyond 100 keV. Computer simulations of interchange reconnection support key features of the observations, including the ion spectra. Important characteristics of interchange reconnection in the low corona are inferred from the data, including that the reconnection is collisionless and that the energy release rate is sufficient to power the fast wind. In this scenario, magnetic reconnection is continuous and the wind is driven by both the resulting plasma pressure and the radial Alfvénic flow bursts."

The Parker Solar Probe may have spotted the origin of high-speed solar winds Kinky magnetic fields near the surface of the sun power the winds’ blasts of gas


Fig. 2: Solar wind during PSP Encounter 10 emerges from two coronal holes.


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