MAPPING A MAGNETIC SUPERSTORM

Jan 27, 2020
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Researchers have mapped the best and worst places in the USA to be during a severe geomagnetic storm resulting from a coronal mass ejection from Jolly Old Mr Sun. 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 led the study. "Hazards are greatest for power systems serving Boston, New York, Philadelphia, Baltimore, and Washington, DC, – a megalopolis of over 50 million people."

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Researchers have mapped the best and worst places in the USA to be during a severe geomagnetic storm resulting from a coronal mass ejection from Jolly Old Mr Sun. 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 led the study. "Hazards are greatest for power systems serving Boston, New York, Philadelphia, Baltimore, and Washington, DC, – a megalopolis of over 50 million people."

Resistive structures in the crust of the Earth measured by the Earthscope project. Credit: Kelbert et al. (2019) [more]

These conclusions are based on a new study of the biggest geomagnetic storm of the Space Age--the Great Québec 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 of Faraday's Law, 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.

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During a geomagnetic storm, geomagnetically induced current (GIC) flows through power lines and the Earth itself. Credit: GAO

In 1989 researchers didn't know much about the Earth-half of the circuit. That has changed. In 2006, the Earthscope 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.

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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]

“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.

See: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2021SW003030

See: spaceweather.com

This is a very interesting study and helps to flesh out the reasons why the power grids in certain areas appear to be more vulnerable to the electrical effects of geomagnetic storms. The full study is available above in the agupubs.onlinelibrary.
Hartmann352
 
Mar 4, 2020
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I never did any research on this, but my experience tells me that the inductance reactance of the grid structure is a thousand fold more determinative than the crust resistance. At what rate does the earth's M field jiggle? How far is that F away from the line F? The grid and it's transformers are designed for a 60 Hz impedance. Or L reactance. If the wiggle increases, the inductance reactance jumps up, causing big jumps in voltage. If the magnetic jiggle is lower than 60 Hz, then the L reactance falls, causing a big jump in current.

The F of the interference(M jiggle) determines the reaction.

Then why does it hit the grids in the east harder? Probability because of the number of grid connections. More connections result in a more dynamic load. And an un-stable reactance. Our grid is not tuned.

The induced current from the M jiggle, might not be the only stimulus. Has anyone looked for a muon spray when the storm hits? Muons are just electrons at a high energy level. And what about the charge fields distorting around our planet. These changing charge fields could stimulate also. There are several of them.

I don't believe we understand solar storm-earth dynamic as well as we think.
 

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