Two-point observations of solar wind parameters

Caption: Near-Earth environment in GSE coordinates with Earth at the origin (red star), the moon (magenta squares) and the ACE (blue) and DSCOVR (orange) spacecraft showing measured velocity vectors at each position. The vectors are colour-coded to run from blue to red, implying that ACE orbits in clockwise direction and DSCOVR in the counter-clockwise direction, when viewed from Earth.

For a number of years ACE has been the only spacecraft situated at the first Lagrangian point (L1) measuring the solar wind just before it impacts Earth’s magnetosphere, acting as our lone watchman in the Earth-impacting portion of solar wind flow. In 2016, DSCOVR, the replacement for ACE became operational, situated in a complimentary orbit around L1, doubling the number of measurement points in the upstream wind. The aim of this project is to take advantage of the pair of similar solar wind observing space craft we currently have access to, by investigating the typical scale sizes of structures in the solar wind that impact the magnetosphere.