Texto para a pergunta
STORMY WEATHER
1 On earth, weather is defined, for the most part, by atmospheric wind (direction and velocity), water (precipitation and humidity), and temperature.
These elements are never in a steady state, and intermittently their level of activity – individually or collectively – can become violent. The giant blob
[bolha] of plasma that Earth orbits also has its mood swings. When activity on the Sun becomes violent, solar flares fling [arremessar] radiation at the
speed of light in all directions, and clouds of plasma break away [se separam], traveling at up to 7 million miles per hour. Radiation can reach Earth’s
atmosphere in eight minutes, and plasma clouds follow in a matter of hours.
2 Storms come and go on both spheres, with varying degrees of impact. Meteorologists, with their measuring instruments and computer models, can
forecast most Earthly weather events in time to forewarn [avisar antecipadamente] the public of impending catastrophes. Solar events are less
predictable.
3 The Sun can have storms of sufficient magnitude that plasma shock waves affect Earth’s magnetic field, creating a violent distortion called a
“geomagnetic storm” that can last six to twelve hours. According to a 2015 BBC report, “the rapidly changing magnetic field generates an electrical
current in any conductive material near the ground, including telephone and power lines, undersea cables, and oil and gas pipelines. Once the electrical
surges reach the power grid, they overload [sobrecarregar] transformers and trip [acionar] their circuit breakers, causing widespread blackouts.” Such an
event happened in 1989, knocking out power for the entire Canadian province of Quebec for twelve hours. In 1859, a “blaze lit the heavens…visible
from Hawaii to London…caused by a super-explosion on the Sun, equivalent to ten billion atomic bombs. In our solar system, it was the biggest stellar
outburst of the last 500 years.” The blast was three times the size of the one in 1989. If one that size were to occur today, according to a UK government
report, it “would likely cause unprecedented chaos. It would disrupt satellite communications and GPS navigation, and trigger [causar, iniciar] global
blackouts lasting up to a year.”
4 “Today, scientists know when a storm is headed toward us, but it’s impossible to predict where on Earth it will hit hardest,” according to a 2016
University of Michigan report. In October 2016, the National Oceanic and Atmospheric Administration’s Space Weather Prediction Center began using a
geospace forecast model – developed by researchers at the University of Michigan and Rice University – that can “give unique data for each 350-squaremile plot [pedaço] of Earth, and up to 45 minutes before a solar storm hits.” It may be enough time for utility companies and satellite operators to “limit
damage to their systems by shutting off key components.”
Adapted from Natural History, February 2018.
The “violent distortion” mentioned in paragraph 3 is most likely connected to which of the following?
