Solar weather has real, material effects on Earth
On Sep. 1, 1859, solar astronomer Richard Carrington . Just before dawn the next day, auroras erupted over most of the Earth, reaching as far south as the Caribbean and Hawaii while southern lights were seen as far north as Chile. The event produced not only a visible light show in areas where they do not typically appear, .
Given the state of technology during Carrington's time, the impact of a geomagnetic storm was limited to disruptions of telegraph service. If something similar happened today, the world's technological infrastructure could grind to a halt. Extreme space weather events such as geomagnetic storms are than in the past. This is because of our greater dependence on technical systems that can be affected by electric currents and energetic particles high in the Earth's atmosphere.
The space weather threat
We might think of space as a silent, empty void and the sun as only a distant source of light and heat. This is not necessarily true. .
Sunspots are that appear darker than the surrounding areas. Sunspots can change continuously and may last for only a few hours to days; or even months for the more intense groups. The peak of sunspot activity is known as solar maximum and the lull is known as solar minimum.
Indicating intense magnetic activity, sunspots accompany secondary phenomena such as bursts of electromagnetic radiation (flares) and coronal mass ejections (CME) —which are sudden eruptions of material —accompanied by solar energetic particles (SEPs). A solar flare is a sudden release of energy from the sun, while a CME shoots hot plasma from the sun into space.
The precise mechanisms that trigger flares and CMEs are still being debated, but the bigger the group of sunspots, . The sun continually ejects high-energy electrons, protons and other nuclei that bombard the Earth. and charged particles hurtling into collision with the Earth's upper atmosphere, where they can cause geomagnetic storms.
Charged particles during geomagnetic storms cause disturbances in the Earth's magnetic field, generating effects on electrical systems. such as voltage disruptions leading to power outages; changes in soil voltage that enhance corrosion in oil pipelines; disruption in satellite, radio and cellular communications networks; exposure to elevated levels of radiation; and reductions in flights with polar routes.
For the most part, the Earth's magnetic field protects humans from the barrage of radiation which comes from the sun. However, the Earth's magnetic field is weaker at either pole and therefore some particles of enter the Earth's atmosphere through geomagnetic storms.
Solar weather effects
The adverse economic impacts of solar activity on the North American power grid have been well-documented. For instance, between 1992 and 2010 reported to the U.S. Department of Energy are attributable to strong geomagnetic activity.
I have been working on the for some time now and thought: "How about the sun?"
Interestingly, while the study of space weather is a rapidly growing field, academic work to assess its overall social and economic impacts appears to be in its infancy.
I am currently working with one of my former graduate students, Zichun Zhao, on the economic impacts of space weather. Our proxy measure of solar activity is the number of sunspots produced by the sun at a given time and, luckily, this data is .
In our empirical analysis, we found that the decreases as solar activity increases. On average, GDP decreases by at least 0.06 percent for every increase of one percent in solar activity.
We find that the negative economic effects of geomagnetic storms are more significant in northern latitudes. However, the effects of geomagnetic storms and have been documented in the , , Sweden, , the , , , and .
Our empirical results indicate that damages caused by geomagnetic storms are much greater in the information and communications sectors.
Provided by The Conversation
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