Shell Mound wrote:TheAustinMan wrote:Regarding the rapid change in tropical cyclone heat potential between June 5 and June 6, that seems to arise from a change in the way the depth of the 26C isotherm is calculated.
What made you suspect that is the case? Do you have a link to the evidence? I would certainly be interested in viewing it.
Tropical cyclone heat potential is calculated using an integration of sea surface temperatures over some depth, so as a first guess one or more of the input datasets (either the 26C isotherm depth, SSTs, or sea height anomalies) was the likely culprit in the sudden uptick in tropical cyclone heat potential.
I took a look at each of these, and the standout dataset was the 26C isotherm depth. Here are a few images of the 26C isotherm depth dataset in past times:
2009,
2010,
2013,
2015,
2017,
2019, and
June 5 2020.
Compare these with the day after the TCHP suddenly changed,
June 6, 2020. You'll notice that evidently something has changed in the way the data is presented/processed. The spatial resolution appears to have increased, and there's no longer a sharp cutoff between the tropics and the subtropics (based on the fact that this happened in 1 day, it's more likely this cutoff was an artifact of data processing rather than an actual physical phenomenon).
