Published in Monthly Weather Review – Taking a Hurricane’s Pulse: Could it lead to a better understanding of storm structure and intensity change?

This work describes a new technique that uses infrared satellite imagery to examine the evolution of the tropical cyclone daily cycle for all Atlantic major hurricanes from 2001-2010.  The imagery reveals cyclical pulses in the cloud field that regularly move outward from the hurricane each day.  These pulses begin near the hurricane’s center at about sunset each day and move outward several hundred kilometers by the following afternoon.  There can be significant changes in hurricane structure as these daily pulses evolve, and they may impact intensity estimates and the size of the hurricane wind field. The repetition of this cycle and in time and space suggests that it may be a fundamental hurricane process.

Screen Shot 2014-11-12 at 3.01.06 PM

Important Conclusions:

1) The tropical cyclone diurnal cycle is a newly discovered phenomenon seen as cyclical pulses in the cloud field that propagate away from the storm center after sunset each day.

2) The timing and position of TC diurnal pulses are highly predicable as they move away from the hurricane inner core each night, eventually reaching hundreds of kilometers from the circulation center by the following afternoon.

3) A 10-yr analysis of North Atlantic major hurricanes indicates that the TC diurnal cycle may be an unrealized, yet fundamental process that can affect storm structure over a deep layer of the atmosphere.

The full paper can be accessed at http://journals.ametsoc.org/doi/abs/10.1175/MWR-D-13-00191.1.