Sargassum alert scientists will develop to reduce damage

Jessica Xanthomilla

Newspaper La Jornada
Sunday, February 20, 2022, p. 12

The large patches of sargassum that reach the Mexican coast have been an interesting problem to solve for the scientific community. While for some the captivating thing has been to know the elements that give rise to its excessive growth, for others, such as the oceanologist María Eugenia Allende Arandía, from the Coastal Engineering and Processes Laboratory of the UNAM Institute of Engineering, the attractive thing is to know the factors that modulate the arrival of the algae and what their trajectories are.

Together with other researchers, he is working on a project to develop an early warning for sargassum so that government agencies and the private sector can have an estimate of the probability of arrival and thus deploy the necessary logistics and have the infrastructure to carry out all its collection.

In interview with the day, Allende Arandía explained that in order to obtain this information they use numerical models with which they carry out experiments. He explained that the study area they are working on begins in the Equatorial Atlantic to the Gulf of Mexico.

“As a basic experiment, we release a certain amount of numerical particles –which are inert because the biology of the algae is not being considered– and we see how they move depending on the current, the speed it carries, but without considering the forcing of the wind,” he said. Later, he added, another experiment is carried out taking into account one percent of the wind forcing and the next considers 2 percent.

He specified that with these studies they found that, once these particles enter the Caribbean region, the wind is of vital importance. in the sense that these particles can reach Central America or they can remain and follow a route to the south of the Greater Antilles or cross and reach what is known as the Loop Current, which runs through the Yucatan Channel, between the peninsula and Cuba.

Researchers have also used another method known as self-organizing maps, that work through unsupervised neural networks where we can find different patterns of current variability. Likewise, the oceanologist said that they apply the mathematical method known as the calculation of coherent Lagrangian structures, which finds zones of convergence or divergence of the current.

Regarding the results, he mentioned that from what was done with the numerical particles, they have found that On average, if they are released in the Equatorial Atlantic, they take approximately three months to approach the Yucatan Peninsula, and that depends on the intensity of the currents and the wind.. This happens with self-organizing maps, so the data obtained they are very similarhe added.