Reproducible Aspects of the Climate of Space Weather Over the Last Five Solar Cycles

• Published in: Space weather Vol. 16; no. 8; pp. 1128 - 1142
• Main Authors: Chapman, S. C., Watkins, N. W., Tindale, E.
• Format: Journal Article
• Language: English
• Published: Washington John Wiley & Sons, Inc 01.08.2018
• Subjects: Auroral activity; Aviation; Charged particles; Climate; Convection; Disruption; Dynamic pressure; Earth; Electric fields; Electric power; Electric power loss; Environmental impact; generalized Pareto distribution; Magnetic fields; Magnetospheres; Magnetospheric-solar wind relationships; Maxima; Radio emission; return times; Ring currents; Satellites; Solar corona; Solar cycle; Solar maximum; Solar wind; space climate; Space plasmas; Space weather; Statistical distributions; Variance; Weather
• ISSN: 1542-7390; 1539-4964; 1542-7390
• DOI: 10.1029/2018SW001884

Each solar maximum interval has a different duration and peak activity level, which is reflected in the behavior of key physical variables that characterize solar and solar wind driving and magnetospheric response. The variation in the statistical distributions of the F10.7 index of solar coronal radio emissions, the dynamic pressure PDyn and effective convection electric field Ey in the solar wind observed in situ upstream of Earth, the ring current index DST, and the high‐latitude auroral activity index AE are tracked across the last five solar maxima. For each physical variable we find that the distribution tail (the exceedences above a threshold) can be rescaled onto a single master distribution using the mean and variance specific to each solar maximum interval. We provide generalized Pareto distribution fits to the different master distributions for each of the variables. If the mean and variance of the large‐to‐extreme observations can be predicted for a given solar maximum, then their full distribution is known. Plain Language Summary Earth's near‐space plasma environment is highly dynamic, with its own space weather. Space weather impacts include electrical power loss, aviation disruption, interrupted communications, and disturbance to satellite systems. The drivers of space weather, the sun and solar wind, and the response seen at Earth have now been almost continually monitored by ground‐ and space‐based observations over the last five solar cycles (more than 50 years). Each of the last five solar maxima has a different duration and peak activity level and as a consequence the climate of Earth's space weather is also different at each solar maximum. We find that some aspects of the space weather climate are in fact reproducible; they can be inferred from that of previous solar maxima. This may help understand the behavior of future solar maxima. Key Points F10.7, AE, DST and solar wind dynamic pressure distributions are characterized for the last five solar maxima At solar maximum the tail of the distribution of return times follows a functional form that is solar cycle invariant If the mean and variance can be predicted, then the space climate of a given solar maximum is known