Solar wind expands from the Sun at the average speed of 400 km/s. It is divided into two components, the slow and the fast solar wind, which originate from the Sun's equatorial belt and the coronal holes, respectively.


The waves of plasma that make up the solar winds spread across our solar system at extremly high temperatures, on average reaching 150,000 K around the Earth. The temperature of the slow component of solar wind averages at 1.4–1.6×106 K, while the fast solar wind has an average temperature of 8×105 K.


Solar wind is composed of approximately equal numbers of ions and electrons; the ion component consists predominantly of protons (95%), with a small amount of doubly ionized helium and trace amounts of heavier ions. The average density of solar wind is 8.7 protons per cubic centimeter.



The interplanetary magnetic field (IMF) is the solar magnetic field, carried by the solar wind throughout the system. It is seen as a vector with three directional components (Bx, By and Bz). When the IMF's direction is southward (negative values), on contact it may cancel the Earth's magnetic field, which points north, and so facilitate the entry of the solar wind particles into the Earth's magnetosphere. Near the Earth the IMF has an average value of about 6.6nT.

solar flare

What is solar wind?

As the Sun's corona reaches temperatures that are too high for the Sun's gravity to keep hold of coronal gases, a stream of plasma is propelled away from the Sun, carrying charged particles (protons, electrons and heavier ionized atoms) as well as magnetic clouds. By monitoring the solar wind's properties (wind speed, density and magnetic field strength and direction) it is possible to predict the wind's effects.


Solar wind monitoring

The most visually appealing effect of solar winds that we can see are the Aurora Borealis and the Aurora Australis lights, which occur as a consequence of solar wind particles interacting with the elements in the Earth's upper atmosphere. However, solar winds have become an increased concern in recent years as they can affect equipment in space (a stronger pulse may hit an orbiting satellite and damage its electronics) and on the Earth, disrupting telecommunications, navigation and even power grids.


What this page does

The National Oceanic and Atmospheric Administration provides solar wind monitoring data from two space weather monitoring satellites, the 17-year old Advanced Composition Explorer (ACE), and its successor, the newly launched Deep Space Climate Observatory (DSCOVR), both originally launched by the NASA. This page aims to present real-time comparative data for both satellites as provided by the NOAA with regard to solar wind properties (temperature, proton density and velocity) and the strength of the interplanetary magnetic field.