""Media outlets are widely reporting on two recent studies in the journal Geophysical Research Letters describing a giant "blob" of warm water that may be responsible for recent ecological and weather anomalies across the United States -- from California's drought to the East Coast's severe winter to the thousands of dying sea lions washing up along the West Coast.
The "blob" -- more precisely, the "warm anomaly" -- is a patch of ocean water just off the coast of the Pacific Northwest that is about 1,000 miles across, 300 feet deep, and 3 degrees Celsius (5 degrees Fahrenheit) warmer than usual. It received its nickname from Nick Bond of Washington State University, lead author of one of the new studies.
Do the new studies actually explain what the media are claiming? Are there potential explanations that are being ignored?
Already, researchers have linked the blob to many of this past year's alarming ecological occurrences. Warmer water is less rich in nutrients, which scientists say has caused effects including a crash in the population of copepods (tiny animals that form the base of the ocean's food web) and the starvation of sea lion pups, causing thousands of the animals to strand themselves onshore. The warm water has also caused tropical fish to appear near Seattle.
The new study by Bond and colleagues also links the blob to the recent weather disturbances. The researchers claim that the blob actually has an atmospheric cause: an unseasonal ridge of high-pressure air hovering above it. This high-pressure air (instead of the low-pressure air typical for the winter) has been associated with the ocean becoming unseasonably calm and warm, removing a major source of rain for the West Coast and contributing to California's drought and the West Coast's warmer-than-usual winter, according to the researchers.
The second study traced the blob to another patch of unseasonably warm water, this one in the Tropics near the intersection of the Equator and the International Date Line. This warm water has been heating up the air above it, directly leading to the unseasonably warm patch of air that is heating the waters off the U.S. coast.
"It's like throwing a rock into a pond," researcher Dennis Hartmann said. "The wave eventually makes its way to the other side."
This same wave of warm air actually crosses the entire North American continent, the researchers found, eventually causing a wet, low-pressure system over the central and eastern United States. This system, called a "North Pacific Mode," contributed to this year's remarkably cold and snowy winter, the researchers claim.
Although North Pacific Modes have been observed before, this past year's was more extreme and longer lasting than has been seen before.
Potential Fukushima link not being investigated
According to media reports, no one knows what has caused the unusually warm Tropical waters responsible for all of these climate and ecological effects. But some have asked whether radioactive material emitted into the ocean by the Fukushima disaster might not be partially responsible.""
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