In El Nino's wake

THE BALTIMORE SUN

The El Nino phenomenon has been known for centuries in Peru. Fishermen there noted the arrival of warm Pacific waters, and a season of poor fishing, around Christmas. They named it El Nino - a Spanish reference to the Christ child. This year's event has already caused drought, fires, floods and storms that have killed hundreds of people and caused millions of dollars in damage around the Pacific. But El Nino (pronounced el neen-yo) can also bring benefits, such as a quiet Atlantic hurricane season and tropical game fish in northern waters.

1. NORTHERN CALIFORNIA - September: Surf temperatures 17 degrees above normal. Anglers hook marlin, mahi mahi, swordfish and other tropical species.

2. SOUTHERN CALIFORNIA - September: Angler hooks a

tripletail, only the second ever caught in California since the 1850s.

3. LOS ANGELES - Summer: Low pressure and temperatures, tropical moisture reduce smog. This could be the most $l smog-free year in 40 years.

4. PERU - September: Forest fire accelerated by drought threatens ancient Inca ruins at Machu Picchu and nearby rain forest.

5. INDONESIA - Sept. 10: Uncontrolled fires, set to clear land but enlarged by three-month drought, send a pall of smoke across parts of Sumatra.

6. MALAYSIA - Sept. 10: Smoke blowing in from Indonesia declared a national disaster. Government launches cloud-seeding in an effort to bring rain.

7. PAPUA NEW GUINEA - Aug. 11: Drought forces closure of a copper mine as low river water stops ore barges.

8. CALIFORNIA - Sept. 15: Waves from Hurricane Linda - the most intense Pacific storm on record with 220-mph winds - sweep five people off a beach.

9. INDONESIA - Sept. 18: 45,000 people evacuated from town of Rengat because of heavy smoke as fires ignite peat bogs. Main airport is closed.

10. MEXICO - Sept. 22: Hurricane Nora batters Mexico's Pacific coast, fells trees. Floods rip away building foundations in Guerrero and Jalisco states.

11. PAPUA NEW GUINEA - Sept. 22:. Sixty die amid food shortages, failed crops because of drought. Gold mines closed.

12. INDONESIA: Sept. 22: At least 251 people are dead of starvation and cholera in a drought-stricken corner of New Guinea.

13. NICARAGUA - September: Government promises emergency food and agriculture aid to 20,000 drought-stricken farmers.

14. INDONESIA - Sept. 26: Indonesian passenger jet crashes in Sumatra, an area shrouded in smoke from bush fires. All 234 people aboard are killed.

15. COSTA RICA - September: Warm water causes giant shrimp, lobsters and other valuable fish species to flee El Salvador's Pacific coast.

16. MEXICO - Oct. 9: Hurricane Pauline rakes Mexican coast. Hundreds die; roads, homes, power lines and communications are destroyed.

17. BRAZIL - Oct. 9: Lowest humidity since 1939 in the Amazon. One farmer trying to burn off 12 acres chars 500. Smoke chokes Manaus. Airports closed.

18. INDONESIA - October: Wildlife suffering in drought. Orangutans killed raiding gardens for food. Elephants, tigers also threaten settlements.

19. NICARAGUA - Nov. 13: Hot, dry conditions and high tides destroy tens of thousands of sea turtle eggs at Playa La Flor, an important nesting beach.

20. COLOMBIA - Oct. 16 : At least two people die and 2,000 are left homeless when rain-swollen rivers burst their banks and sweep away 200 houses.

21. BRAZIL - Oct. 20: High waves and rare east and southeast winds strip sand from Rio de Janeiro's Copacabana beach.

22. ECUADOR - Nov. 21: Flooding and mudslides caused by torrential rains kill 27 people in three weeks. Perhaps 10,000 people are homeless, or have had their homes severely damaged by rains.

How an El Nino forms

Normal conditions: Strong equatorial trade winds blow across the central Pacific, pushing sun-warmed surface water and rainy weather to the west, toward Indonesia. Deep cold water rises to the surface.The cold water is rich in nutrients, allowing tiny phytoplankton to grow in the presence of sunlight. In turn, phytoplankton support the food chain upon which fish, birds and commercial fisheries depend.

El Nino conditions: The trade winds weaken. Warm water moves back toward the central and eastern Pacific. Warm-water species turn up along normally cold shores. Thermocline - the boundary between warm and cold water - sinks. Animals in food web based on cold-water phytoplankton die or migrate.

How El Nino conditions affect weather: Evaporation generated by the warm surface temperature brings rain and storms to parts of the eastern Pacific. Robbed of moisture, western Pacific countries suffer drought.

How severe is this El Nino?

1982 El Nino vs. 1997 El Nino

The El Nino of 1982 was considered the most severe this century, causing more than $13 billion in damage. The 1997 El Nino is predicted to be as severe or worse. Here is a comparison of sea surface temperature for the 1982 and 1997 El Ninos.

Costs of 1997 El Nino vary

NEW ZEALAND: Government predicts $130 million in crop and livestock losses from fierce storms and cold, dry weather.

PAPUA NEW GUINEA: Government offers $14 million to aid 700,000 people threatened by drought and hunger. Australia adds $360,000. Coffee crop hit.

SOUTH AFRICA: Authorities fear an El Nino drought could halve the country's corn crop, costing more than $213 million in lost exports.

PERU: International aid banks have approved $300 million in loans for flood and drought prevention measures and reconstruction in Peru if disaster strikes.

MEXICO: Hurricanes and storms leave hundreds dead and thousands homeless on southwestern coast. Millions in damage. Intensity blamed on El Nino.

UNITED STATES: Southeastern coastal states have benefited from a dearth of Atlantic hurricanes. El Nino's influence suppresses storm development.

How it is tracked

The El Nino event in 1982-1983 was well under way by the time scientists noticed it. This year's event was detected 11 months ago thanks to a new arsenal of satellites, buoy arrays and sensors, all operated at an annual cost to the United States of about $5 million.

The instruments track developments across the Pacific hour by hour. Ocean and atmospheric conditions are transmitted to data centers and posted on the Internet almost immediately.

Key elements of the system:

TOPEX/Poseidon

A U.S./French satellite launched in 1992 to an altitude of 830 miles. Warm water expands, raising sea level slightly. TOPEX can detect these slight sea level changes and convert the data into temperature readings. Scientists can then map and track changing surface temperatures around the globe.

TAO (Tropical Atmosphere Ocean) Array

A system of 70 ATLAS buoys moored across the tropical Pacific. More than 7 feet wide and 16 feet tall, each buoy is anchored in up to 19,700 feet of water, with sensors as deep as 1,600 feet. They gather and relay data on wind, sunlight, air and water temperature, humidity and rain to shore stations via satellite.

Global Lagrangian Drifters

A squadron of more than 400 free-floating buoys deployed throughout the Pacific and around the world. They relay data on currents, sunlight, atmospheric pressure, water temperatures and salt content.

Climactic data is also gathered from instruments handled by volunteers on commercial ships, and installed at shore stations across the Pacific.

SOURCES: Associated Press, National Oceanographic and Atmospheric Administration; National Centers for Environmental Prediction; Reports to the Nation On Our Changing Planet; Todd Mitchell, University of Washington

Pub Date: 11/25/97

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