COLUMBIA — Columbia experienced record-low temperatures in the past two days, and atmospheric scientists are saying the region's climate history suggests such unusually low temperatures may be associated with a developing El Niño in the Pacific Ocean.
“When an El Niño tends to set in, the summer leading into an El Niño tends to be cooler around here,” said Anthony Lupo, chair and professor at MU’s atmospheric sciences department.
According to NOVA, a program devoted to science on Public Broadcasting System, the amount of energy in a typical El Niño is immense. In order to warm that much water of the Pacific ocean by 1 to 2 degrees Celsius, it would take more than a million power plants - 1,000 megawatts each - running full throttle for a year. That’s as much energy produced by half a million 20 megaton hydrogen bombs. In other words, it's more energy than what has been burned by fossil fuels in the U.S. since the beginning of the century.
Source: Public Broadcasting System
Sunday and Monday's lows of 56 degrees at Columbia Regional Airport tied the record lows for those dates, which were set in 1979.
El Niño’s effects are more evident in the winter months. In Missouri, the phenomenon is associated with warmer winters and less snowfall. The southern part of the country tends to be wetter and cooler, while the northern part tends to experience warmer conditions.
The National Oceanic and Atmospheric Administration said in a news release that an El Niño event can help to dampen Atlantic hurricane activity, as well as reduce the risk of Florida wildfires. However, negative effects include damaging storms in California and the southern U.S.
"In general, the El Niño tends to be a benefit to the U.S. in terms of keeping the heating bills down,” Lupo said.
National Weather Service scientists earlier this month announced the arrival of El Niño. El Niño occurs on average every two to five years and typically lasts about 12 months.
Suzanne Fortin, the science and operations officer at the Kansas City Weather Forecast Office in Pleasant Hill, said El Niño is still in its infancy and won’t come to maturation until the late-fall and early-winter period. Only then can the extent of El Niño’s impact be gauged, she said, adding that the effects were expected to last through winter in late 2009 and early 2010.
During non-El Niño years, easterly winds off the coast of South America push warm equatorial waters west toward the coast of Indonesia. This “pushing” of the warm surface waters causes warming in the western Pacific waters. According to NASA, this movement of water also causes the sea level to be about half a meter higher in the western Pacific than in the east.
During El Niño, the warm waters in the western Pacific begin flowing back toward the east, increasing the ocean temperature in the eastern Pacific.
Lupo said the closer the warming waters get to the coast of South America, the stronger an El Niño will become and the warmer mid-Missouri’s winter temperatures will be.
The last El Niño was in 2006 and 2007, but it was weak.
“A weak El Niño tends to bring more moderate winters in terms of temperatures and snow fall” to Missouri, Lupo said. “Strong El Niños bring very warm winter conditions around here, which means a definite chance of much smaller snowfall totals.”
While the exact mechanisms of how El Niño works are still being studied, it is clear that after seasonal changes, El Niño is the most influential factor for weather patterns.