Solar Radiation Management (SRM) was first imagined by scientists during the Cold War. It promises a comparatively cheap, quick fix for the environmental problems faced by our planet: the continuous dispersal of aerosols into the atmosphere to reflect and absorb Sunlight, cooling the planet. In effect, SRM means dimming the Sun. It would inject billions of tiny particles into the upper atmosphere to bounce a bit of Sunshine back into space, lowering Earth's surface temperature a notch or two.

Sometimes nature does the same: more than 15 million tonnes of sulphur dioxide thrust into the stratosphere by the 1991 eruption of Mount Pinatubo in the Philippines cooled the planet by more than half a degree C for about two years. Volcanic eruptions spew out plumes of aerosols. The 1883 eruption of Krakatoa reportedly lowered global temperatures by 1 degree Celsius. The best modelling suggests SRM would achieve the same result.

Stratospheric aerosol injection is one of a suite of technologies aimed at large-scale manipulation of the climate, known as geoengineering. SRM comes under the category of ‘solar geoengineering.’ But who gets to decide if and when to roll it out? The United Nations Framework Convention on Climate Change (UNFCCC) is the body currently charged with negotiating climate policymaking at the international level. International policymaking of any sort is notoriously difficult, especially for an issue that affects just about every sector of the global economy. Even small national delegations must delicately balance the demands of their governing parties with actors ranging from civil society to industry.

An international agreement around solar geoengineering could mean starting from scratch, beginning with a push to convince the world’s governments that it’s necessary—assuming no rogue actor launches a project on its own, first. But the democratic processes involved here are more about power than psychology—and certain actors exercise a lot of power in the UNFCCC process.

Could a group of low-lying countries, devastated by storms and rising seas, reach a tipping point and pull the trigger for this technology? Could deployment result from a geopolitical power play between the United States and China? Critics believe that the more SRM is legitimized through experiments and positive mainstream attention, the more likely it is that these speculative scenarios become real.

Credit for Image Above: Photo by David McNew/Getty Images
From InTheseTimes.com

Image credit: (NASA/Naval Research Laboratory/Parker Solar Probe)
Taken by the Parker Solar Probe's WISPR (Wide-field Imager for Solar Probe) instrument, the image shows a coronal streamer, also known as a helmet streamer - a loop of electrically charged coronal gases and plasma connecting two regions of opposite polarity on the Sun, extended by the Solar wind. That bright dot you see is actually Mercury. And the black dots are an artefact from background correction.

NASA's Parker Solar Probe, the first human-made object to fly into the Sun's corona, completed its first solar flyby on November 11, collecting a wealth of unprecedented data about the workings of our magnificent home star. And now, weeks later, that data is arriving home. Parker has sent back its first photo from its new home orbiting the Sun.
Usually pictures we obtain of these streamers are sketchy, so, from a distance of just 27.2 million kilometres (16.9 million miles), Parker is already providing a much more detailed perspective of the streamer's structure, with at least two visible rays.

NASA hasn't told us what temperatures were like at the time the spacecraft snapped this shot, but the probe is equipped with state-of-the-art heat shielding that will protect it up to the temperatures of 1,644 Kelvin (1,370 degrees Celsius or 2,500 degrees Fahrenheit) it's expected to reach.

The next flyby is slated to begin on April 4 next year, but scientists have plenty to sink their teeth into for the time being. "We don't know what to expect so close to the Sun until we get the data, and we'll probably see some new phenomena," said Parker project scientist Nour Raouafi. "Parker is an exploration mission - the potential for new discoveries is huge."
 
Source:https://www.sciencealert.com/this-is-the-first-image-ever-taken-from-inside-the-corona-of-the-sun  MICHELLE STARR  14 DEC 2018

Image credit: (ESA/Royal Observatory of Belgium)

Something We've Never Seen Before: The Sun's North Pole
A solar mission has given us a glimpse of the Sun’s poles, in the form of an image pieced together from data collected by the European Space Agency's PROBA-2 (PRoject for OnBoard Autonomy 2) satellite, in orbit around Earth.

Earth - and most of the objects in the Solar System - orbits the Sun in a flat disc, close to the star's equator. This is called the ecliptic plane. We launch spacecraft out on this ecliptic plane, for practical reasons. The spin of Earth on its axis gives a rocket a boost, meaning it takes less effort to get it into space. The closer the launch is to the equator, the greater the boost. It would be much harder to launch a rocket from Earth's polar regions. So, rockets launched from Earth are already travelling in the ecliptic plane and therefore normally aren't in a position to peek at the Sun's poles. It is possible to get out of this plane, but it's quite hard and time-consuming. This is the reason why we've never been able to directly see either of the Sun's poles.

There has actually been one probe that looked at the Sun's poles, though: Ulysses, which looped over the top of the Sun's poles at a distance of nearly 322 million kilometres (200 million miles) - but none of its instruments were a camera.

This time, we're not looking at a photograph either, strictly speaking - but it's very close. When spacecraft observe the solar atmosphere, they gather data on everything along their line of sight, also viewing the atmosphere extending around the disc of the Sun, and scientists can use this to infer the appearance of the polar regions. Slice by tiny slice, as the Sun rotates, PROBA-2 takes readings of these elements in extreme ultraviolet wavelengths, then combines them into a reconstruction of the Solar poles.

ESA scientists have been building these images since June this year, uploading them into a database so that they can observe how the Sun's poles change over time. This is so that they can build on the knowledge gleaned by Ulysses, and try to learn more about the dynamics of solar phenomena at the polar regions - such as coronal holes, Alfvén waves and Rossby waves.

For actual photos, we have to wait for ESA's Solar Orbiter, scheduled for launch in 2020. It's not going to orbit the poles, but will zoom around at high-enough latitudes that it will be able to image those mysterious and elusive regions.
 
Source: https://www.sciencealert.com/here-s-something-you-ve-probably-never-seen-before-the-sun-s-north-pole MICHELLE STARR  4 DEC 2018

Scientists at Queen’s University Belfast have led an international team to the ground-breaking discovery that magnetic waves crashing through the Sun may be key to heating its atmosphere and propelling the solar wind.

“The Sun is the source of energy that sustains all life on Earth but much remains unknown about it. However, a group of researchers at Queen’s have now unlocked some mysteries in a research paper, which has been published in Nature Physics.

“In 1942, Swedish physicist and engineer Hannes Alfvén predicted the existence of a new type of wave due to magnetism acting on a plasma, which led him to obtain the Nobel Prize for Physics in 1970. Since his prediction, Alfvén waves have been associated with a variety of sources, including nuclear reactors, the gas cloud that envelops comets, laboratory experiments, medical MRI imaging and in the atmosphere of our nearest star — the Sun.

“Scientists have suggested for many years that these waves may play an important role in maintaining the Sun’s extremely high temperatures but until now had not been able to prove it.”

Read the entire article posted online March 6, 2018 by Queen’s University, Belfast at sciencedaily.com.