Environment, Headlines, Latin America & the Caribbean

ENVIRONMENT-VENEZUELA: Life-Protecting Lightning

Humberto Márquez

CARACAS, Sep 16 2003 (IPS) - Venezuela’s spectacular Catatumbo lightning phenomenon, which contributes to restoring the Earth’s atmospheric ozone layer, continues today thanks in great part to the marshlands national park at the southern end of Lake Maracaibo.

Admirers of the natural light display hope to put the area under the protection of UNESCO (United Nations Educational, Scientific and Cultural Organisation).

"This is an exceptional phenomenon, the greatest source of its type (electrical storms) for regenerating the planet’s ozone layer and a spectacle of great beauty that UNESCO should declare natural heritage of humanity," environmentalist Erik Quiroga, the leading proponent of the idea, told IPS.

It was Quiroga who asked Venezuela to propose Sep. 16 as International Day for the Preservation of the Ozone Layer, an initiative approved by the United Nations General Assembly in late 1994 at the request of the Group of 77, a bloc of developing countries.

The date was chosen to commemorate the adoption on Sep. 16, 1987 of the Montreal Protocol on substances that deplete the ozone layer, such as chlorofluorocarbons (CFCs), used as industrial refrigerants and aerosols, and the pesticide methyl bromide.

The Catatumbo cloud-to-cloud lightning forms a voltage arc more than five km high during 140 to 160 nights a year, 10 hours a night, and as many as 280 times an hour.

This meteorological phenomenon occurs over the marshlands where the Catatumbo River, which originates in Colombia, feeds into Lake Maracaibo.

The area sees an estimated 1,176,000 electrical discharges per year, with an intensity of up to 400,000 amperes, and visible up to 400 km away, according to the measurements taken by scientists from Simón Bolívar University, located in Caracas.

This climatic phenomenon, for which people like Quiroga are seeking UNESCO protection, is a source of pride for the residents of the oil-producing state of Zulia in western Venezuela and is a favourite among eco-tourists visiting the region.

"It is also known as the Maracaibo Beacon because its light can be seen from the entrance to the Gulf of Venezuela and from the neighbouring Dutch Antilles," scientist Gonzalo Godoy told IPS.

There are specific circumstances that give rise to the Catatumbo lightning: the trade winds enter the depression where the lake is located and run into the Perijá mountains (on the Colombia-Venezuela border), creating low-pressure air masses in the south, over the flat water of the marshes.

The collision with the winds coming from the Andes Mountains causes the storms and associated lightning, a result of electrical discharges through ionised gases, specifically the methane created by the decomposition of organic matter in the marshes. Being lighter than air, the gas rises up to the clouds, feeding the storms.

When electrical energy is applied to oxygen it produces ozone, a gas that is a potent oxidant and considered toxic in the lower atmosphere (up to 12 km altitude), but beneficial in the upper stratosphere because it forms a layer that filters out the sun’s ultraviolet rays, protecting plant and animal life on Earth.

Estimates by NASA (the U.S. National Aeronautics and Space Administration) suggest that the so-called hole in the ozone layer could expand to 28 million square km this year, an area three times the size of the United States.

The principal cause of the thinning of the atmospheric ozone layer is the industrial emission of CFC gases. The "hole", which occurs over Antarctica, is a periodic phenomenon, reaching its maximum size during the southern hemisphere spring, September through November.

The ozone generated by the electrical storms in the Earth’s temperate regions can be toxic because the atmosphere is denser and the gas tends to concentrate at altitudes of five to 12 km, while in the hotter zones, the atmosphere is light and the ozone ascends rapidly to higher altitudes.

"In any case, the contribution of phenomena like the Catatumbo lightning, although valuable, is very small, because electrical storms provide just 10 percent of the ozone that is formed on Earth," notes Quiroga.

The country that sees most lightning is Brazil, with 70 million electrical discharges each year. But the specific sites with greatest annual frequency of lightning are Bogor, east of Java in Indonesia, and the Catatumbo area in Venezuela.

Bogor has an average of 223 days of cloud-to-ground storms a year, and is listed in the Guinness Book of World Records for the 322 days of storms recorded in the 1916-1919 period.

However, although there are no conclusive studies that quantify the ozone contributed to the atmosphere, the Catatumbo lightning is considered the greatest single generator of ozone, judging from the intensity of the cloud-to-cloud discharge and great frequency.

"The basis of the phenomenon is the 300,000 hectares of marshland at the south end of Lake Maracaibo, 270,000 hectares of which are protected as a national park," pointed out Godoy, a biologist and head of the environmental group Procuencas, active in protecting wetlands.

Godoy warned that "the water surfaces that contribute to the formation of the lightning could be reduced as a result of water use for agriculture purposes in the Catatumbo highlands. The river provides 60 percent of the freshwater for the lake."

The Maracaibo also suffers increased salinity as a result of dredging of the canal that connects it to the Gulf of Venezuela and therefore, the Caribbean Sea.

Quiroga, meanwhile, stresses that this is why "it would be best to obtain UNESCO protection for this natural heritage site, which would also raise public awareness about the need to preserve the ozone layer."