Solar wind shock wave hit the Earth today; did it spark a geomagnetic storm?
Sun, a huge ball of energy released a coronal mass ejection or CME on November 19 and now its belated arrival can be seen impacting Earth. According to the information provided by spaceweather.com. a shock wave in the solar wind hit Earth's magnetic field today, Friday (November 25) at around 2:30 UT or 8:00 am IST. The solar wind can be the belated arrival of the CME, the report said. It added that so far, no geomagnetic storm seems to have been sparked, but an alert has been sounded for auroras.
"A shock wave in the solar wind hit Earth's magnetic field today, Nov. 25th, at approximately 0230 UT. It might have been the belated arrival of a CME that left the sun on Nov. 19th, hurled in our direction by an erupting filament of magnetism. So far the weak impact has not caused a geomagnetic storm," spaceweather.com said.
It can be known that earlier NOAA forecasters said that there was a chance of G1-class geomagnetic storm on November 20 or 21 when a high-speed stream of solar wind was expected to hit Earth.
Meanwhile, for people who are not aware of what is a coronal mass ejection or CME can know that the outer solar atmosphere called corona is made up of strong magnetic fields. Where these fields are closed, often above sunspot groups, the confined solar atmosphere can suddenly and violently release bubbles of gas and magnetic fields called coronal mass ejections.
A large CME can contain a billion tons of matter that can be accelerated to several million miles per hour in a spectacular explosion. Solar material streams out through the interplanetary medium, impacting any planet or spacecraft in its path. CMEs are sometimes associated with flares but can occur independently.
Coming to the solar wind, according to NASA, the solar wind is very weak compared to the wind on Earth, however it is faster. When solar wind speeds are measured it typically shows at 1-2 million miles per hour.
Solar wind density is usually about 100 particles per cubic inch. Thus, a typical pressure from the solar wind is measured in nanopascals whereas at the Earth's surface, the atmospheric pressure is 100 kilopascals, and surface winds are about 100 pascals. Since solar wind is measured in nanopascals it is approximately 1000 million times weaker than winds here on Earth.