Comparing Spectra
ACE long, year
==================
ObsPer   DerPer
------------------
60.4     60.4*
36.9     34.9*
22.9     22.1*
17.9     17.9*
14.1     13.8*
 9.1      9.1
 7.8      7.8
 6.9      6.9
 5.6      5.6
 4.9      4.9
 3.46     3.46
 2.874    2.874
 2.5      2.5

* weak


   ACE Accumulated cyclone energy (ACE) 1851-2016
   http://www.esrl.noaa.gov/psd/data/timeseries/monthly/ACE/