By: Martha Vindas Montero
In the climatic conjuncture of this year, 2017, we have perceived more hydro meteorological phenomena with more frequency and more intensity. Yet it is not a matter of perception alone, but of science. In its 2013-2014 report, The Intergovernmental Panel on Climate Change (IPCC) states that regardless of frequency, hurricanes will become increasingly extreme with stronger winds and more flood water, and contextualizes that “If hurricanes behave this way there will be less time for immediate disaster prevention by governments and residents, especially in the case of out-of-place and low-lying construction. ”
An example of this is that Hurricane Otto and Storm Nate that left a trail of human and substantial material losses throughout Central America. As a result, its impact was of a regional dimension and it is important to consider the part played by the isthmus of Central American territories and their variable climatic conditions which make it more vulnerable (not only by its geographical location but) because of the active presence of the Intertropical Convergence Zone (ITCZ).
Anders Levermann of the Potsdam Climate Research Institute explains that “when a hurricane forms, it takes the energy from water which is now warmer due to global warming”. It is noted that the University of Costa Rica states there are no scientific studies that support the hypothesis that global warming is increasing the regularity of the hurricanes and tropical storms. However; if the modification of the climate on earth (and consequently the warming of the oceans) increases the strength of these systems, it causes abrupt changes in the climate and the events become more constant, intense and strong. Therefore, if the temperatures continue to increase, we will have more convective events with potential cyclonic effects on Central America and the Caribbean.
The Climate Observatory of Costa Rica’s National High Tech Center (CENAT) commented that the climatic conditions of October 2017 are similar to those of November 2016 which generated low pressure systems, culminating in Otto and Nate. Although the phenomenon of La Niña has not been officially declared, the Pacific Ocean maintains colder temperatures and in the Caribbean it is warmer than usual. The dynamics of the mix of cold wind flow with warm winds is what facilitates cyclonic formation. They also remind us that Hurricane Mitch and Juana developed in years where there was a La Niña.
In addition to all these climatic conditions, we have ground that is saturated with rainfall plus the presence of numerous tropical waves and these anomalous conditions have generated this extensive system that spans from the Pacific Ocean to the Caribbean Sea in a prolonged system of low pressure generating unusual conditions in the atmosphere with conditions of a high concentration of water which was what caused the extreme events such as with Otto and Nate.