
ACE - Advanced Composition Explorer
The data from the observations of the spacecraft laboratory ACE describes the energy particles in the solar wind. It is used for forecasting of the space weather, magnetic storms and geomagnetic disturbances on Earth. The measurements collected are very important in the studying of the structure and the processes of our sun.
The Space Observatory ACE is positioned in the first Lagrange point (L1) between the Sun and Earth, so it keeps constantly proper position without spending much fuel. At this L1 point under normal conditions the ACE space laboratory takes measurements from the solar wind about 45 minutes before the solar energy particles reach the Earth.
Sector structure of the interplanetary magnetic field and the solar wind by ACE
Solar wind at the moment (NOAA)

Number of protons from the solar wind per unit volume measured by ACE through SWEPAM. (Measured)

Average speed of protons from the solar wind measured by ACE/SWEPAM. Same as the speed of air molecules, known as "wind speed" of the Earth surface. (Measured)

Hydraulic pressure of the solar wind is the force per unit area required to stop the solar wind flow. This is similar in concept to the force a surface wind exerts on a sail. The solar wind ram pressure depends on the solar wind speed and density. (Derived)

The temperature of protons in the solar wind. It is measured by ACE/SWEPAM.(Measured)

The strength of the interplanetary magnetic field (IMF) as measured by the ACE Magnetometer (MAG). (Measured)

The angle between the IMF and the geomagnetic axis. When the IMF is southward, antiparallel fields near the magnetospheric subsolar point allow merging between the IMF and geomagnetic fields. This process increases the transport of solar wind mass, momentum, and energy into the Earth's magnetosphere. This process can also open the magnetosphere to solar energetic particle radiation. In severe conditions this radiation can threaten high altitude aircraft in high latitude and polar regions. Under less severe conditions this radiation can still threaten polar orbiting spacecraft. This quantity depends on IMF components measured by ACE/MAG. (Derived)

The direction of the IMF perpendicular to the geomagnetic axis. This affects the details of solar wind-magnetosphere interactions; however, this is of tertiary importance compared to the IMF magnitude and polar angle. This quantity also depends on IMF components measured by ACE/MAG. (Derived)

The solar wind energy input to the magnetosphere that drives magnetospheric convection. It appears as an electric potential imposed across the polar ionosphere. The quantity shown here is an estimate of the asymptotic convection potential based on ACE/SWEPAM and ACE/MAG measurements as well as the work of Boyle, et al. (Journal of Geophysical Research 102, 111, 1997.) This estimate is asymptotic because it does not account for the time delays such as those imposed by friction between the ionosphere and the neutral atmosphere.
Relativistic Electron Forecast Model - REFM
View the last 7-days history plots with the data of the four ACE instruments:
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Sources:
Advanced Composition Explorer Homepage, Rice Space Institute и NOAA SWPC.
