Comment on “Origins of energetic ions in the cusp” by K. J. Trattner et al.

Abstract

The paper by Trattner et al. [2001, hereinafter referred to as TETAL] reanalyzes the data of Chen et al. [1998, hereinafter referred to as CFS] and attempts to prove two statements: first, that the energetic ions observed in the cusp by CFS were actually accelerated at the bow shock and then transported to the cusp, and second, that the detected ions are not accelerated locally. Quoting TETAL's abstract, “An alternative explanation for the energetic particle events is that they are accelerated at the quasi‐parallel bowshock, then transported downstream and enter the cusp along newly reconnected field lines or some other solar wind entry mechanism… No local acceleration is required to explain the observed CEP events up to 150 keV/e.” We object that neither assertion of TETAL is defensible on theoretical or experimental grounds. Indeed we find the conclusions of the paper are flawed by both statistical and logical errors. In section 1 we outline the logical flaws, in section 2 we outline the misuse of the scientific method, in section 3 we outline the improper use of statistics, and in section 4 we outline the mishandling of spacecraft data. Finally, in section 5 we apply the scientific method of hypothesis testing to the two theories, arguing that given complete ignorance of the data, the hypotheses of CFS are preferable to TETAL.