Reply to “Response to ‘Limitations in the Hilbert Transform Approach to Locating Solar Cycle Terminators’ by R.J. Booth”

Abstract

This is a reply to Leamon et al., Solar Phys., 2021 (in press, hereinafter L21), which is a response to Booth, Solar Phys. 296, 108, 2021. We agree that, given a fixed constant subtracted from the sunspot counts prior to the Hilbert transform, the L21 algorithm to determine historical sunspot cycle terminators is robust, but add that it has no dependence at all on start and end dates. However, the prediction of a future terminator relies on properties of the transform, which do depend on both start and end dates. For the Cycle 24 terminator, the 95% confidence interval (CI) implied by L21’s statistics includes all dates until September 2022. For each new month that the terminator is proven not to occur, the CI’s end date will be extended.