Statistical Survey of the Terrestrial Bow Shock Observed by the Cluster Spacecraft
Maksimovic, M.; Santolik, O.; Němec, F.; Soucek, J.; Krupar, V.; Kruparova, O.; Å afránková, J.; Němeček, Z.; Merka, J.
Czech Republic, United States, France
Abstract
The terrestrial bow shock provides us with a unique opportunity to extensively investigate properties of collisionless shocks using in situ measurements under a wide range of upstream conditions. Here we report a statistical study of 529 terrestrial bow shock crossings observed between years 2001 and 2013 by the four Cluster spacecraft. By applying a simple timing method to multipoint measurements, we are able to investigate their characteristic spatiotemporal features. We have found a significant correlation between the speed of the bow shock motion and the solar wind speed. We have also compared obtained speeds with time derivatives of locations predicted by a three-dimensional bow shock model. Finally, we provide a list of bow shock crossings for possible further investigation by the scientific community.