By IPS Correspondents
LIMA, Mar 19 2002 (IPS)

A small white shark captured off the Peruvian coast appears to be a messenger from El Niño, the much feared climate phenomenon whose return this year had been ruled out by South American meteorologists.

The shark, found earlier this month at just over 12 degrees latitude south, belongs to a shark species that lives in warm waters, and under normal circumstances would not be found beyond six degrees south. Usually the cold Humboldt current, originating in Antarctica, prevents the sharks from venturing beyond that point.

The presence of the shark in the waters off the resort town of Señoritas seems to confirm the fears of farmers, textile business owners and insurance companies in several parts of the world, who are now preparing to confront the possible return of El Niño.

The phenomenon is based on the cyclical occurrence of a warm Pacific Ocean current that begins off Australia and heads toward the equatorial coast of South America. The warmer surface waters cause temporary climate shifts around the world, triggering excessive rainfall and flooding in some areas, and severe drought in others.

The El Niño current is warmer than the surrounding waters and is usually just five to 10 cm deep, though can be hundreds of km wide.

The international scientific community has created a network to monitor and study the causes and the regularity of these threatening shifts in the climate, and has made important advances in knowledge about the phenomenon. But scientists are still unable to predict accurately the gestation of El Niño, which occurs at somewhat irregular intervals.

Just two months ago, affirmations that El Niño would not occur this year were issued by spokespersons from Peru’s National Hydrology and Meteorology Service (SENAMHI) and from the Sea Institute of Peru (IMARPE), and by Adm. Hugo Arévalo, head of the Multi-Disciplinary Committee for the Study of the El Niño Phenomenon.

This reflected the conclusion of a Jan 8-10 meeting of the Regional Scientific Committee on the El Niño Phenomenon, made up of experts from Chile, Colombia, Ecuador and Peru, who analysed data gathered by satellites and by sensors in the Pacific Ocean.

The study also included input from biologists, who track the behaviour of marine species.

The surface water temperatures along the northern Peruvian coast in January were two to three degrees warmer than normal, which triggered torrential rains and flooding in some areas.

On Feb 5, Lima received its heaviest rainfall in the last 32 years. The flooding of rivers in the coastal plains and in the sierra killed eight people and destroyed or damaged 1,700 homes and hundreds of hectares of cultivated farmland.

As a result of the excessive rains, President Alejandro Toledo called on experts from SENAMHI, IMAPE and the Multidisciplinary Committee to determine whether this was a precursor to a new manifestation of El Niño.

“What do we tell the public? Do we declare the country to be in an emergency situation and adopt the necessary measures, or not?” Toledo asked the specialists.

“In effect, it involves a warming of the ocean currents, but it is the result of other factors and will not have the duration that characterises El Niño,” responded Arévalo and Ronald Wodman, head of the Geophysical Institute of Peru, in a report at the time.

Arévalo and Wodman explained in the document that the floating sensors distributed throughout the path normally followed by the El Niño current, from Australia to the Ecuadorian and Peruvian coasts, reported the flow of a warm current toward the South American seaboard. But they said they still could not be sure it was indicative of the El Niño phenomenon.

“El Niño does not generally occur in such short cycles, and the last intense phenomenon appeared in 1998. According to its habitual cycles, it should reappear between 2004 and 2007,” wrote the experts.

However the U.S. National Oceanic and Atmospheric Administration as well as international institutions have begun to issue reports warning of the possible return of El Niño this year.

A satellite map of sea temperatures for Mar 11, two days after the white shark appeared in Señoritas, revealed a mass of water of 28 degrees near the port of Paita, 1,100 km north of Lima.

Furthermore, in Huacho, just 130 km from the Peruvian capital, surface water temperatures reached 27 degrees.

“We are probably facing a lighter El Niño, one that will not have the catastrophic proportions of the one we saw in 1998,” commented Arévalo in response to the new information.

According to the technical definitions, El Niño is “light or moderate” if surface water temperatures rise by up to three degrees Celsius, and is considered “strong” when the increase is five to seven degrees above the seasonal average.

This change has a direct impact on the atmospheric temperature, which during the day hovers at four to six degrees higher than the sea surface temperature.

This accelerates the evaporation process, causing persistent and intense rainfall in some areas, with the consequent flooding, while the shift in winds causes drought in others.

“We will have to wait until April to see if the phenomenon persists and if we will have a normal (Southern Hemisphere) autumn this year, summer-like, with temperatures of 25 to 26 degrees, and a temperate winter, with temperatures above 20 degrees,” said Ena Jaimes, of SENAMHI.

While some experts can afford to see whether their predictions are born out, for many economic sectors, the information is of urgent importance.

David Lemor, head of the Garment Committee of the National Society of Industries, said that the main sales campaign for his sector “is usually in the winter, and a prolonged summer could ruin many companies” that are dependent on textile raw materials.

There is deep concern among farmers, not only because of the change in rainfall, but also because some crops require a specific range of temperatures to grow properly to maturity.

Some are already calling on the government to take steps to curb the effects of possible floods and to prepare equipment to deal with the likely mudslides that would block roads and prevent farmers from transporting their goods to market.

Excerpt: