A few weeks before the disaster, a researcher of MIT, Dr. Kerry Emanuel, in Nature an article showing had published that, since the beginning of the Fifties, the intensity of the tropical cyclones had increased and that this tendency was correlated with the increase in time in the temperatures in surface in the ocean on the level in the tropics.

In fact, during the phase of the formation of Katrina, the temperature of surface water of the Gulf was higher than the normal of more than one degree. However, the scientists prudently refuse to bind the dynamics of an extreme event particular to the phenomenon of climatic change and prefer to remain in the field of the trend analysis of long term. Moreover, the dynamics of the cyclones is the result of complex couplings between the atmospheric field and the oceanic field and, as the specialists in the cyclones underline it, like Dr. Lynn Shay of the university of Miami, it is the depth of the hot water section which at the end of the day makes the difference in the force of a cyclone.

Thus, passage of cyclone in formation above "loop current" - running hot circular which traverses the Gulf, whose hot water then reached a 100 meters depth, with literally "doped" the cyclone. Propelled of category 5 then, it attenuated of category 4 only while approaching the shore.


Related links : Geostationary Operational Environmental Satellite