SPACE WEATHER: About

The Van Allen Probes Space Weather ICD is available here.


Space weather is the reaction of the near-Earth space environment to the variable energy input into that environment by the Sun. We usually refer to space weather as occurring in Earth's upper atmosphere (specifically the ionosphere and thermosphere) and the magnetosphere. The plasma and electric and magnetic fields surrounding Earth change in response to the variable solar wind and Interplanetary Magnetic Field (IMF). Coronal Mass Ejections (CME) from the Sun influence bulk motions in the solar wind and IMF while associated solar flares cause increased energetic particles and direct radiation from the Sun. The effects of this variability include geomagnetic storms and substorms, in which Earth's intrinsic magnetic field is deformed by changing electric currents, increased or decreased intensity of the Van Allen belts, and even complete formation and destruction of transient radiation belts.


Understanding space weather involves unraveling the interplay between the solar wind and the IMF with the Earth's plasma environment. In order to predict space weather events, we need to have advanced warning of what the solar surface, solar wind, and IMF are doing. However, we also need a detailed model of how variations in those solar inputs interact with Earth's magnetic field, plasma environment and upper atmosphere and how each of those components influence each other. Knowing that a CME is heading toward Earth may allow us to predict that some type of space weather phenomenon will probably occur, but it does not help us know exactly what phenomena will occur until we better understand the physics of the near-Earth environment


Predicting space weather becomes more vital as we become more dependent on space-based technology. Activity in the ionosphere interferes with technological systems that rely on radio communication such as GPS. Increased radiation is a thread to manned and unmanned spacecraft, causing damage to electronics and power systems as well as posing health risk to astronauts. Increased heating can puff up the upper atmosphere causing satellite orbits to degrade. Changes in the magnetic field near Earth's surface caused by geomagnetic storms can induce extraneous currents in power lines, oil pipeline, and railways, which can cause power outages and even fires. As solar activity increases with the solar cycle, all of these issues become more likely to occur.


The space weather data is collected by ground stations partners and gathered and processed at JHU/APL. Ground stations are supplied, operated, and funded by interested parties external to the RBSP Program and Project. Currently, two international ground station partners have been identified and agreements are in place:

 



Page Last Modified: May 23, 2014