Statistical analysis of corotating interaction regions and high speed streams

Many people believe the solar wind to be a constant, steady flow of charged particles from the Sun; however, this is generally not the case. Coronal holes on the Sun produce very fast solar wind, known as a high-speed stream (HSS), which can greatly affect the Earth's magnetosphere. When a HSS compresses the slower-moving solar wind ahead of it, a corotating interaction region (CIR) is created. Due to the compression, CIRs have a density spike, intense magnetic fields, and they are followed by a HSS which is faster than the preceding solar wind. The interaction of CIRs/HSSs with Earth's magnetic field may cause geomagnetic storms and affect space weather, so understanding HSSs is important. Since the Sun is currently in a solar minimum, HSSs occur very frequently. We have collected a number of HSSs that follow CIRs, and we will present an analysis of the mean and standard deviation of varying parameters for this collection of HSSs.