[SFDXA] MAPPING A MAGNETIC SUPERSTORM

[Bill]

/From Tony N2MFT://
/

*CME IMPACT ON JUNE 15TH:*Arriving a few hours earlier than expected, a 
CME hit Earth's magnetic field on June 15th at 0437 UT. The glancing 
blow sparked a minor G1-class storm,underway now 
<https://www.swpc.noaa.gov/products/planetary-k-index>. More storms are 
possible in the hours ahead as Earth moves through the CME's dense, 
magnetized flank.*Aurora alerts:*SMS Text <https://spaceweatheralerts.com/>

*MAPPING A MAGNETIC SUPERSTORM:*Researchers have mapped the best and 
worst places in the USA to be during a severe geomagnetic storm. For 
residents of some big cities, the news is not good.

"Resistive structures in the crust and mantle of the Earth make cities 
along the east coast of the USA especially vulnerable to geomagnetic 
storms," says Jeffrey Love of the US Geological Survey (USGS), who 
ledthe study 
<https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2021SW003030>. 
"Hazards are greatest for power systems serving Boston, New York, 
Philadelphia, Baltimore, and Washington, DC, – a megalopolis of over 50 
million people."

<https://spaceweather.com/images2022/12jun22/resistivity.jpg>
*Above:*Resistive structures in the crust of the Earth measured by 
theEarthscope <https://www.earthscope-program-2003-2018.org/>project. 
Credit:Kelbert/et al./(2019) 
<https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/9781119434412.ch8>[more 
<https://eos.org/science-updates/taking-magnetotelluric-data-out-of-the-drawer>]

These conclusions are based on a new study of the biggest geomagnetic 
storm of the Space Age--theGreat Québec Blackout 
<https://spaceweatherarchive.com/2021/03/12/the-great-quebec-blackout/>of 
March 13, 1989. Millions of Quebecois spent a long winter night without 
lights or heat after a pair of CMEs hammered Earth's magnetic field. The 
Hydro-Québec power grid was down for more than 9 hours.

What would happen if the same geomagnetic storm struck again? That's 
what Love's team wanted to find out. They combined old measurements of 
magnetic activity during the 1989 storm with new measurements of Earth's 
crust to pinpoint the hazard zones.

At this point, it may be useful to review what happens during a 
geomagnetic storm. When a CME hits Earth's magnetic field, our magnetic 
field vibrates. If you had a sensitive-enough compass, you could see the 
needle quivering. Next, because ofFaraday's Law 
<https://en.wikipedia.org/wiki/Faraday%27s_law_of_induction>, electrical 
currents begin to flow through conductors. Power lines, pipes, even 
rocks conduct these geomagnetically induced currents (GICs). Together, 
Earth and power lines form an electrical circuit; if too much current 
flows into the power grid it can cause a blackout.

<https://spaceweather.com/images2022/12jun22/gic.jpg>
*Above:*During a geomagnetic storm, geomagnetically induced current 
(GIC) flows through power lines and the Earth itself. Credit:GAO 
<https://www.gao.gov/products/gao-19-98>

In 1989 researchers didn't know much about the Earth-half of the 
circuit. That has changed. In 2006, theEarthscope 
<https://www.earthscope-program-2003-2018.org/>project began sounding 
our planet's crust to determine the 3D electrical properties of deep 
rock. It turns out, there are huge variations in conductivity from place 
to place. The type of rock a city sits on determines how vulnerable it 
is to geomagnetic storms.

In retrospect, Québec was especially vulnerable. The province sits on an 
expanse of Precambrian igneous rock that does a poor job conducting 
electricity. When the March 13th CMEs arrived, storm currents found a 
more attractive path in the high-voltage transmission lines of 
Hydro-Québec. Unusual frequencies began to flow through the lines, 
transformers overheated and circuit breakers tripped.

Assuming that the Québec storm was underway again, Love's team mapped 
electric fields around much of North America. Measured in units of Volts 
per kilometer (V/km), these fields predict how much current will be 
pushed through wires at ground level. The higher the value, the bigger 
the hazard.

<https://spaceweather.com/images2022/06jun22/output.gif>
*Above*: If you live near an orange dot you might be in trouble during a 
geomagnetic superstorm. The color-coded dots represent peak geoelectric 
field amplitudes. Credit: Love et al (2022). [movie 
<https://spaceweather.com/images2022/06jun22/output.gif>]

"Peak 1-min-resolution geoelectric field amplitudes ranged from 
21.66 V/km in Maine and 19.02 V/km in Virginia to <0.02 V/km in Idaho," 
says Love. "Our maps show where utility companies might concentrate 
their efforts to mitigate the impacts of future magnetic superstorms."

With Solar Cycle 25 ramping up to a new Solar Maximum expected in 2025, 
the hazard maps are coming not a moment too soon.

You can read Love et al.'s original research in the May 2022 edition of 
the research journal/Space Weather/.Click here 
<https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2021SW003030>.


https://spaceweather.com

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