To watch live bowshock: http://pixie.spasci.com/DynMod/
Real time data from the ACE spacecraft (top two panels) are used to predict the shape and location of these boundaries at the present time and into the near future (The time is Universal Time as measured at Greenwich, England. Click here for information on conversions to local time).
In the figure to the right, the Earth is in the center, and is illuminated from the left by the Sun (not shown). In this view, we are looking down upon the North pole; thus the figure represents the equatorial plane. The solar wind emanating from the Sun is super-magnetosonic with respect to the Earth, so that a shock wave is formed. As the solar wind flows through the shock it is slowed down, and the pressure of the solar wind is balanced by the pressure from the Earth's magnetic field. The boundary at which this pressure balance is achieved is called the magnetopause.
The ACE spacecraft monitors the solar wind from a position about 200 Earth radii (RE) sunward of the Earth. The real time solar wind data from this spacecraft allows us to predict what will happen at the Earth many minutes before the solar wind actually reaches us. Important solar wind values obtained from the ACE observations include the z-component of the interplanetary magnetic field (Bz) measured in units of nano-Tesla, and the dynamic pressure (also called the momentum flux) of the solar wind, measured in units of nano-Pascal.
Geosynchronous orbit (where many weather and communication satellites orbit) is depicted by the green dashed circle.
Here are all the gory details.
This movie is updated every five minutes
(unless there is an extended data gap in the ACE observations).
A severe geomagnetic storm is whipping through Earth’s magnetosphere, causing disruption to power systems and spawning a beautiful green, St. Patrick’s Day-themed aurora that stretched as far south as Oregon and Illinois.
The storm, which began late Monday as a weak G1 intensified Tuesday morning, climbing to a G4 on the five-point scale, according to the Space Weather Prediction Center. This makes the storm the strongest in the current solar cycle, says spaceweather.com. The current storm is in season, so to speak, since they are most common around the equinoxes.