Steve: In my ignorance, it isn’t clear that we should be concerned if MPI does rise with tropical ocean temperature unless we also know that the factors that prevent TC’s from achieving maximum intensity remain constant. IIRC, Wind sheer is predicted to increase on a warmer planet. I vaguely remember reading that the strongest hurricanes are limited because their winds bring up cooler water from below it front of the hurricane.
Some simple physics illustrates the pitfalls of over-simplifying potential energy/intensity. In space, gravitational potential is converted to velocity using mgh = 0.5*mv2. In the atmosphere, growing drag (friction with air) eventually negates the entire force of gravity, and velocity reaches a plateau (terminal velocity). Drag plays a more dramatic role on falling ping pong balls than falling golf balls.
It does seem that vertical wind shear has an effect in the other direction.
That is, warmer temperatures increase vertical wind shear, which leads to less intense TCs, all other things being equal.
Example:
"In most cases, stronger vertical wind shear is detrimental to intensification (DeMaria and Kaplan 1994), but some TCs are able to intensify in environments with moderate-to-strong vertical wind shear magnitudes (e.g., Rios-Berrios et al. 2016a,b; Ryglicki et al. 2018). The intensity and structure of a TC can determine the extent to which a TC resists the destructive effects of vertical wind shear, but the reasons for this are not fully understood and have not been explored in detail."
The Intensity and Size-Dependent Response of Tropical Cyclones to Increasing Vertical Wind Shear, Peter M. Finocchio & Rosimar Rios-Berrios (2021)
Steve: In my ignorance, it isn’t clear that we should be concerned if MPI does rise with tropical ocean temperature unless we also know that the factors that prevent TC’s from achieving maximum intensity remain constant. IIRC, Wind sheer is predicted to increase on a warmer planet. I vaguely remember reading that the strongest hurricanes are limited because their winds bring up cooler water from below it front of the hurricane.
Some simple physics illustrates the pitfalls of over-simplifying potential energy/intensity. In space, gravitational potential is converted to velocity using mgh = 0.5*mv2. In the atmosphere, growing drag (friction with air) eventually negates the entire force of gravity, and velocity reaches a plateau (terminal velocity). Drag plays a more dramatic role on falling ping pong balls than falling golf balls.
Frank,
It does seem that vertical wind shear has an effect in the other direction.
That is, warmer temperatures increase vertical wind shear, which leads to less intense TCs, all other things being equal.
Example:
"In most cases, stronger vertical wind shear is detrimental to intensification (DeMaria and Kaplan 1994), but some TCs are able to intensify in environments with moderate-to-strong vertical wind shear magnitudes (e.g., Rios-Berrios et al. 2016a,b; Ryglicki et al. 2018). The intensity and structure of a TC can determine the extent to which a TC resists the destructive effects of vertical wind shear, but the reasons for this are not fully understood and have not been explored in detail."
The Intensity and Size-Dependent Response of Tropical Cyclones to Increasing Vertical Wind Shear, Peter M. Finocchio & Rosimar Rios-Berrios (2021)
Also worth considering factors other than just storm intensity
https://www.mattball.org/2023/08/the-horror-of-climate-change.html