TC Diurnal Pulse Archive

The graphics in this archive use the two objective metrics created by and detailed in Ditchek et al. (2019a) and Ditchek et al. (2019b) to identify pulse type and electric activity in Atlantic basin tropical cyclones (TCs), respectively. For details on data sets used and how to download the graphics in the archive, please see the README. For brief details on the criteria for both objective metrics and their associated terms and definitions, expand the below.

To objectively identify pulse type, four criteria are used:
  1. Cooling (Warming) Cloud Tops: lower (upper) quartile of 6-h IR BT difference values
  2. On-The-Clock: spatial location of cloud tops follow the diurnal clock schematic (Ditchek et al. 2019a, Fig. 2b)
  3. Areal Criterion: upper half of cloud-top areal coverage distribution
  4. Longevity: number of hours in a given day where the above 3 conditions were satisfied to account for outward propagation
Pulse Type Terms and Definitions: To objectively determine electric activity, three criteria are used:
  1. Pulse Lightning Flash Density: upper half of the distribution
  2. Areal Criterion: upper half of pulse lightning areal coverage distribution
  3. Longevity: number of hours in a given day where the above 2 conditions were satisfied
Electric Activity Terms and Definitions: For more details on the two objective metrics, please see Ditchek et al. (2019a) and Ditchek et al. (2019b).


2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020


I created this archive in order to document TC diurnal pulses in past storms. If you're doing a case study and are presenting or publishing your work, or if you just want to share graphics from this archive on social media, please do! All images in this archive are free to use and share - I just ask that you use the following citation:

Ditchek, S.D, 2020: TC Diurnal Pulse Archive,


GridSat-B1 is updated quarterly and WWLLN lightning flash data is updated daily. Therefore, when HURDAT2 and SHIPS are updated with the previous season's best tracks and shear values, new graphics will be generated for the archive.