Figure 2. Plots of Maximum Potential Intensity (MPI) of tropical cyclones against sea surface temperatures (a): MPI estimated from monthly mean atmospheric temperature soundings and ocean temperatures at several tropical cyclone sites (indicated by different symbols) and compared with the empirical curve for North Atlantic derived by DeMaria and Kaplan (1994); (b): MPI estimated from greenhouse conditions constructed by adding the MECCA model simulated atmospheric and oceanic temperature changes near the tropical cyclone sites in (a) to the observed monthly mean temperature soundings at these sites. Rhomboidal symbols indicate these estimations at the different sites (not distinguished) and the solid thick line is the best fit curve to these points. Thin dashed lines indicate the sense of MPI change and thick vertical dash lines show the changing cyclogenesis limit.