Comments on "Isentropic Analysis of a Simulated Hurricane"
  This paper describes Comments to the paper of Mrowiec et al. published in the J. Atmos. Sci. in May 2016 (Vol 73, Issue 5, pages 1857-1870) and entitled "Isentropic analysis of a simulated hurricane".   It is explained that the plotting of isentropic surfaces (namely the isentropes) requires a precise definition of the specific moist-air entropy, and that most of existing "equivalent potential temperatures" lead to inaccurate definitions of isentropes.   It is shown that the use of the third law of thermodynamics leads to a definition of the specific moist-air entropy (and of a corresponding potential temperature) which allow the plotting of unambigous moist-air isentropes.   Numerical applications are shown by using a numerical simulation of the hurricane DUMILE. 
Pascal Marquet
physics.ao-ph physics.flu-dyn physics.geo-ph