(CNN) -- In their quest for a better understanding of the weather phenomena known as El Niño and La Niña, scientists are taking a closer look at wind currents and water temperatures in the Pacific Ocean.

Together, El Niño, warmer than usual waters in the Pacific, and La Niña, colder than usual waters in the Pacific, have taken the brunt of blame for the year's natural catastrophes: hurricanes, floods and fires.

Last year, El Niño brought on a dramatic drought, which contributed to a 70 percent decline in agricultural output, Busalacchi added.

This year, there have been 13 named tropical storms, compared with seven in 1997.

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"In the Pacific, just within the past week, two typhoons have hit the Philippines," noted NASA oceanographer Tony Busalacchi. ( 327 K/15 sec. AIFF or WAV sound)

Oceanographers say the phenomena, which do not occur every year, contribute to sometimes-wild weather changes around the globe. ( 228 K/10 sec. AIFF or WAV sound)

The current La Niña is expected to remain in the Pacific through spring.


El Niño and La Niña have been blamed for many of this year's natural disasters

Busalacchi said that when warm Pacific water is pushed outside its normal range, warmer and drier conditions typically develop over the southern part of the United States. ( 347 K/16 sec. AIFF or WAV sound)

Better predictions could help determine what crops may hold up under the extreme weather that typically follows the Pacific phenomena. That could be helpful in determining, for instance, how much heating oil some nations may need to endure particularly harsh winters.

The northern part of the United States sometimes gets more precipitation under these conditions, he said.

In order to better predict weather conditions that result from El Niño and La Niña, scientists are stepping up their studies both above and below the surface of the Pacific.

Correspondent Marsha Walton contributed to this report.

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