By CHRISTINA NYQUIST
Everyone is familiar with weather systems on Earth like rain, wind and snow. But space weather – variable conditions in the space surrounding Earth – has important consequences for our lives inside Earth’s atmosphere.
Solar activity occurring miles outside Earth’s atmosphere, for example, can trigger magnetic storms on Earth. These storms are visually stunning, but they can set our modern infrastructure spinning.
On Jan. 19, scientists saw a solar flare in an active region of the Sun, along with a concentrated blast of solar-wind plasma and magnetic field lines known as a coronal mass ejection that burst from the Sun’s surface and appeared to be headed for Earth.
When these solar winds met Earth’s magnetic field, the interaction created one of the largest magnetic storms on Earth recorded in the past few years. The storm peaked on Jan. 24, just as another storm began.
“These new storms, and the storm we witnessed on Sept 26, 2011, indicate the up-tick in activity coming with the Earth’s ascent into the next solar maximum,” said USGS geophysicist Jeffrey Love.” This solar maximum is the period of greatest activity in the solar cycle of the Sun, and it is predicted to occur sometime in 2013, which will increase the amount of magnetic storms on Earth.
Magnetic storms, said Love, are a space weather phenomenon responsible for the breathtaking lights of the aurora borealis, but also sometimes for the disruption of technology and infrastructure our modern society depends on. Large magnetic storms, for example, can interrupt radio communication, interfere with global-positioning systems, disrupt oil and gas well drilling, damage satellites and affect their operations, and even cause electrical blackouts by inducing voltage surges in electric power grids. Storms can also affects airline activity — as a result of last weekend’s storm, both Air Canada and Delta Air Lines rerouted flights over the Arctic bound for Asia as a precautionary measure. Although the storm began on the 19th of January, it did not peak until January 24th.
While this particular storm had minor consequences on Earth, other large storms can be crippling, Love said. He noted that the largest storm of the 20thcentury occurred in March, 1989, accompanied by auroras that could be seen as far south as Texas, and sent electric currents into Earth’s crust that made their way into the high-voltage Canadian Hydro-Quebec power grid. This caused the transformer to fail and left more than 6 million people without power for 9 hours. The same storm also damaged and disrupted the operation of satellites, GPS systems, and radio communication systems used by the United States military.
While large, the 1989 storm pales in comparison to one that occurred in September 1859 and is the largest storm in recorded history. Scientists estimate that the economic impact to the United States from a storm of the same size in today’s society could exceed $1 trillion as a result of the technological systems it could disrupt.
The USGS, a partner in the multi-agency National Space Weather Program, collects data that can help us understand how magnetic storms may impact the United States. Constant monitoring of Earth’s magnetic field allows us to better assess the impact of these phenomena on Earth’s surface. To do this, the USGS Geomagnetism Program maintains 14 observatories around the United States and its territories, which provide ground-based measurements of changes in the magnetic field. These measurements are being used by the NOAA Space Weather Prediction Center and the US Air Force Weather Agencyto track the intensity of the magnetic storm generated by this solar activity.
In addition to providing data to its customers, the USGS produces models of the Earth’s magnetic field that are used in a host of applications, including GPS receivers, military and civilian navigational systems, and in research for studies of the effects of geomagnetic storms on the ionosphere (a shell of electrons and electrically charged atoms and molecules surrounding Earth), atmosphere, and near-space environment.