Title: Quantifying the average and the likelihood of increases in space weather indices and in situ measurements during Solar Cycles 20-23
Authors: Whitney Q. Lohmeyer; Anthony Pang; Kerri Cahoy; Yuri Shprits
Addresses: Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA ' Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA ' Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA; Department of Earth Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA ' Department of Earth Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA; Department of Earth and Space Sciences, University of California Los Angeles, Los Angeles, CA 90095, USA; Skolkovo Institute of Science and Technology, Odintsovsky District, Moscow Region, 143025, Russia
Abstract: It is known that space weather harshly affects spacecraft performance, yet spacecraft operations and understanding the cause of anomalies can be challenging due to the complexity of environmental metrics. In this work, we analyse five metrics and in-situ measurements (Kp, Dst, and AE index, and high-energy proton and electron flux) throughout Solar Cycles 20-23 (1964 to 2008), and provide a baseline for the environment during the phases of the solar cycles (maximum, minimum, declining or ascending). We define increased activity as activity greater than two median absolute deviations (MADs) above the average activity for each phase. MAD is used, rather than standard deviation, because it is more resilient to outliers. The average and MAD values are tabulated in Table 3 to Table 6. We determine the probability that increased activity occurs 3, 14 or 30 days before a random day to distinguish between increased/quiet activities and to aid in correlating intensifications of the environment and anomalous satellite performance.
Keywords: satellite anomalies; radiation effects; space weather indices; space weather measurements; solar cycles; spacecraft performance.
DOI: 10.1504/IJSPACESE.2013.058856
International Journal of Space Science and Engineering, 2013 Vol.1 No.3, pp.230 - 252
Received: 05 Oct 2013
Accepted: 28 Oct 2013
Published online: 30 Apr 2014 *