Riding On the Tail of A CME

Solar storms more severe when two events ‘slipstream’ behind each other

Solar storms more severe when two events 'slipstream' behind each other

A research team led by Imperial College London has presented in a new study that Coronal Mass Ejections (CMEs) or solar storms could be more extreme than previously believed when they “slipstream” each other or when two such events follow each other. Modeling of an extreme space weather event that missed the Earth narrowly in 2012 shows that it could have been worse if another one occurred.

Coronal Mass Ejections (CMEs) are explosions of vast amounts of magnetized material from the Sun, which travel at high speeds and release a large amount of energy in a short period. When the CMEs reach the Earth, they trigger auroras, but they can also disrupt satellites and communications.

The most extreme of space weather events are likely to be catastrophic, causing power blackouts that would damage transformers, and it could take years to repair. Therefore, precise monitoring and forecasting are important to reduce possible damage.

The research team analyzed a large CME that happened on July 23, 2012, which narrowly missed the Earth by a couple of days. It traveled at around 2 250 km/s (1 400 mps), making it comparable to one of the biggest events on record– the 1859 Carrington event.

“The 23 July 2012 event is the most extreme space weather event of the space age, and if this event struck the Earth, the consequences could cause technological blackouts and severely disrupt society, as we are ever more reliant on modern technologies for our day-to-day lives,” said lead author Dr. Ravindra Desai from the Department of Physics at Imperial.

“We find however that this event could actually have been even more extreme– faster and more intense– if it had been launched several days earlier directly behind another event.”

The team studied one of the possible causes to identify what made the storm so extreme, and determined that it was the release of another CME — on July 19, just a few days before — that ‘cleared’ the path for another.

CMEs travel faster than the ambient solar wind, the stream of charged particles constantly flowing from the sun. This means the solar wind exerts drag on the traveling CME, slowing it down.

However, if a previous CME has recently passed through, the solar wind will be affected in such a way that it will not slow down the subsequent CME as much. This is similar to how race car drivers ‘slipstream’ behind one another to gain a speed advantage.

solar-storms-oct-1-2020

The July 23 event. Image credit: NASA/STEREO

The team developed a model that accurately represented the traits of the July 23 event, then simulated what would happen if it had happened earlier or later, or closer to the July 19 event.

The researchers found that by the time of the July 23 event, the solar wind had recovered from the July 19 event, thus, the previous event had a small impact. However, the model showed that if the latter event happened earlier– nearer the July 19 event– it could have been more extreme and could have possibly reached up to 2 750 km/s (1 700 mps).

“We show that the phenomenon of ‘solar wind preconditioning’, where an initial CME causes a subsequent CME to travel faster, is important for magnifying extreme space weather events,” said co-author Han Zhang.

“Our model results, showing the magnitude of the effect and how long the effect lasts, can contribute to current space weather forecasting efforts.”

“There have been previous instances of successive solar storms bombarding the Earth, such as the Halloween Storms of 2003,” co-author Emma Davies added.

“During this period, the sun produced many solar flares, with accompanying CMEs of speeds around 2 000 km/s. These events damaged satellites and communication systems, caused aircraft to be re-routed, and a power outage in Sweden.”

“There is always the possibility of similar or worse scenarios occurring this next solar cycle, therefore accurate models for prediction are vital to helping mitigate their effects.”

Reference

“Three-Dimensional Simulations of Solar Wind Preconditioning and the 23 July 2012 Interplanetary Coronal Mass Ejection” – Desai, R. T. et al. – Solar Physics – DOI: 10.1007/s11207-020-01700-5 – OPEN ACCESS

Abstract

Predicting the large-scale eruptions from the solar corona and their propagation through interplanetary space remains an outstanding challenge in solar- and helio-physics research. In this article, we describe three-dimensional magnetohydrodynamic simulations of the inner heliosphere leading up to and including the extreme interplanetary coronal mass ejection (ICME) of 23 July 2012, developed using the code PLUTO. The simulations are driven using the output of coronal models for Carrington rotations 2125 and 2126 and, given the uncertainties in the initial conditions, are able to reproduce an event of comparable magnitude to the 23 July ICME, with similar velocity and density profiles at 1 au. The launch time of this event is then varied with regards to an initial 19 July ICME and the effects of solar wind preconditioning are found to be significant for an event of this magnitude and to decrease over a time-window consistent with the ballistic refilling of the depleted heliospheric sector. These results indicate that the 23 July ICME was mostly unaffected by events prior, but would have traveled even faster had it erupted closer in time to the 19 July event where it would have experienced even lower drag forces. We discuss this systematic study of solar wind preconditioning in the context of space weather forecasting.

Featured image credit: NASA/STEREO

from:    https://watchers.news/2020/10/04/cme-slipstream-research/

“Thank You For Asking”

DHS Braces For ‘Potential EMP Attack’ As Presidential Election Nears 

The U.S. Department of Homeland Security (DHS) released a new report warning about a “potential” electromagnetic pulse (EMP) attack against the U.S.

DHS’s warning published Thur. (Sept. 2), or about 60 days until the U.S. presidential election on Nov. 3, indicates there are “evolving threats against the American homeland, most recently highlighting efforts to combat an Electromagnetic Pulse attack which could disrupt the electrical grid and potentially damage electronics.”

The department released an EMP status report via the Cybersecurity and Infrastructure Security Agency (CISA) that said the “key actions to address known EMP-related vulnerabilities to critical infrastructure.”

CISA said an EMP attack could “disrupt, degrade, and damage technology” embedded in critical infrastructure systems. Widespread blackouts could be seen if an EMP was to damage the nation’s electrical grid, resulting in additional flare-ups of socio-economic turmoil.

“EMP attacks are part of the emerging threats against our nation and demand a response,” said Senior Official Performing the Duties of the Deputy Secretary Ken Cuccinelli.

“That is why DHS is taking these contingencies very seriously, working diligently to mitigate our risks and equipping our state and local partners with the resources they need to do the same. We’ve made significant progress and look forward to work ahead,” Cuccinelli said.

CISA Director Chris Krebs said top priorities of the agency is to mitigate threats associated with EMPs:

“Over the past year, we have worked with interagency and industry partners to identify the footprint and effects of EMP threats across our National Critical Functions, and are developing sustainable, efficient, and cost-effective approaches to improving the Nation’s resilience to EMPs,” Krebs said.

To combat these emerging threats, President Trump signed an executive order in March 2019, delegating power to the White House for EMP preparedness.

We recently quoted Peter Vincent Pry, ex-chief of staff of the Congressional EMP Commission, who wrote an op-ed that said the virus pandemic from China has “exposed dangerous weaknesses in U.S. planning and preparation for civil defense protection and recovery, and those weaknesses surely have been noticed by our potential enemies: China, Russia, North Korea, Iran, and international terrorists.”

Pry warned that “China has been planning to defeat the U.S. with an EMP and cyber “Pearl Harbor” attack for a quarter-century.”

DHS nor CISA gave any more information on ‘evolving EMP threats’ on the American homeland. There was not mention of whether the threat could be from a solar storm or EMP weapons. However, the EMP status report did mention DHS is currently running EMP pilot tests to assess EMP vulnerability on infrastructure:

“Finally, DHS is partnering with other federal departments and agencies, state, local, tribal, and territorial entities and the private sector to field test a more resilient critical infrastructure. There are a number of field demonstration (or pilot) projects planned and underway by both DHS and DOE to assess EMP vulnerability and then deploy, evaluate, and validate EMP mitigation and protection technologies.

“One such pilot is the San Antonio Electromagnetic Defense Initiative, designed to show how an entire region can become resilient against an EMP. These pilots are multisector, multifunction efforts, seeking to ensure key capabilities continue to function in a post EMP environment and that by maintaining those key functions we can expedite a full recovery. Working with federal interagency partners, DHS will play a major role in ensuring communications systems remain operational and, by ensuring key systems which are protected against EMP, are also protected against other threats such as cyber-attacks.” – EMP status report

One EMP-expert and friend-of-the-site summed up the report perfectly:

“We recognize the threat and we’re working on it and you don’t need to know any more than that, thank you for asking…”

The warning comes just two months before the U.S. presidential election…

from:    https://www.zerohedge.com/geopolitical/dhs-braces-potential-emp-attack-presidential-election-nears?utm_campaign=&utm_content=ZeroHedge%3A+The+Durden+Dispatch&utm_medium=email&utm_source=zh_newsletter

New Solar Activity

FARSIDE SOLAR ACTIVITY: Solar activity has been very low for more than two weeks. A change could be in the offing. During the early hours of August 3rd, a new active region on the farside of the sun announced itself with a bright CME. The Solar and Heliospheric Observatory (SOHO) recorded the eruption:

The CME is not heading for Earth. It is billowing away from the sun’s farside, well off the sun-Earth line.

What’s next? Because the blast site is hidden behind the sun’s limb, we cannot yet inspect it and assess its potential for future eruptions. However, it should rotate into view in the days ahead, possibly bringing an end to two weeks of quiet.

from:   spaceweather.com

Geomagnetic Storms Coming

FULL HALO CME, STORM WARNING: A coronal mass ejection (CME) is heading directly for Earth. It left the sun during the early hours of June 21st, and is expected to sweep up one or two lesser CMEs already en route, before it reaches Earth sometime on June 22nd. Click to view a movie of the “full-halo” CME, then scroll down for more discussion:

NOAA forecasters estimate a 90% chance of polar geomagnetic storms when the CME arrives. This doesn’t mean that a major space weather event is in the offing. The storm could be mild. It all depends on how the magnetic field of the CME connects to the magnetic field of Earth at the time of impact. According to NOAA, there’s only a 10% chance of nothing happening, so stay tuned.

from: spaceweather.com

Strong Solar Flare

OLSTICE AURORA WATCH: On June 18th, sunspot AR2371 unleashed the strongest solar flare in nearly 2 months. The M3-class explosion caused a brief shortwave radio blackout over North America, and it hurled a CME into space. SOHO (the Solar and Heliospheric Observatory) recorded a movie of the expanding cloud:

The CME is not heading directly for Earth. Nevertheless, it is probably geoeffective. According to NOAA computer models, the CME should deliver a glancing blow to our planet’s magnetic field during the late hours of June 21st. High-latitude sky watchers should be alert for solstice auroras.

from:    spaceweather.com

Solar Flares in The Offing

NCREASING CHANCE OF FLARES: NOAA forecasters have boosted the odds of an M-class flare today to 25%. The reasons are circled in this June 12th image from NASA’s Solar Dynamics Observatory:

Sunspots AR2367 (left) and AR2360 (right) are growing with unstable magnetic fields that harbor energy for M-class solar flares. At the moment, both active regions are crackling with low-level C-class flares. It may be just a matter of time before a more significant eruption occurs.

fr:  spaceweather.com

Solar X-Flare 5/05

X-FLARE: The sun is no longer quiet. Emerging sunspot AR2339 unleashed an intense X2-class solar flare on May 5th at 22:11 UT. NASA’s Solar Dynamics Observatory captured the extreme ultraviolet flash:

A pulse of UV radiation and X-rays from the flare caused a strong radio blackout over the Pacific side of Earth. This map shows the extent of the blackout, which affected frequencies below 20 MHz. Mariners, aviators, and ham radio operators are the type of people who might have noticed the disturbance.

The explosion also hurled a CME into space: movie. Traveling faster than 1100 km/s (2.5 million mph), the expanding cloud does not appear to be heading for Earth.

In addition to causing a radio blackout, the flare also caused a radio burst. Immediately after the flare, a roar of static bellowed from the loudspeakers of shortwave receivers on Pacific isles and western parts of North America. Amateur radio astronomer Thomas Ashcraft of New Mexico recorded the outburst:

“The sound file is in stereo with one channel at 22 MHz and the other at 23 MHz,” says Ashcraft. “It is very intricate if listened to with headphones.”

What caused this burst of “solar static”? The same magnetic explosion that caused the flare also produced beams of electrons. As the electrons sliced through the sun’s atmosphere, they generated a ripple of radio-loud plasma waves. Astronomers classify solar radio bursts into five types; this one was a mixture of Type III and Type V.

from:    spaceweather.com

New CME

CME, POSSIBLY EARTH-DIRECTED: A magnetic filament snaking around the sun’s southern hemisphere erupted on May 3rd. The blast did not create a pulse of electromagnetic radiation (i.e., a solar flare), but it did hurl a CME into space. The Solar and Heliospheric Observatory recorded the expanding cloud:

Although the CME is not moving directly along the sun-Earth line, it might still be geoeffective. A glancing blow is possible on May 5th or 6th. NOAA analysts are evaluating this possibility as they receive additional coronagraph data. Stay tuned for updates in the hours ahead.

fr/spaceweather.com

SOlar FLares

OLAR FLARE AND RADIO BLACKOUT: Sunspot AR2257 erupted on Jan. 13th, producing an M5-class solar flare at 04:24 UT. A pulse of extreme UV radiation from the flare ionized Earth’s upper atmosphere over Australia and the Indian Ocean. Mariners and ham radio operators may have noticed a brief communications blackout at frequencies below about 10 MHz. This map from NOAA shows the affected region:

We do not yet know if the flare also produced a coronal mass ejection (CME). If so, the plasma cloud will probably miss Earth because of the sunspot’s off-center location on the solar disk.

More flares could be in the offing. AR2257 has an unstable ‘beta-gamma-delta’ magnetic field that seems poised to explode again. NOAA forecasters estimate a 40% chance of M-class flares and a 10% chance of X-flares on Jan. 13th.

fr/spaceweather.com

Large Coronal Hole

HOLE IN THE SUN’S ATMOSPHERE: A vast hole has opened in the atmosphere over the sun’s south pole, and it is spewing solar wind into space. The gaseous gap, a.k.a. a ‘coronal hole,’ is colored dark-purple in this extreme ultraviolet image from NASA’s Solar Dynamics Observatory:


Curved lines trace the sun’s magnetic field in this EUV image from SDO

Coronal holes are places where the sun’s magnetic field opens up and allows solar wind to escape. A stream of solar wind flowing from this particular hole is expected to reach Earth’s orbit on Jan. 4-5. The bulk of the stream will flow south of our planet. However, not all of it will miss. NOAA forecasters estimate a 40% chance of polar geomagnetic storms when the solar wind arrives in the next 48 hours.

fr/spaceweather.com