Temperatures in the Pacific Ocean play a role in where and how strong tornadoes will be in the United States. Researchers from the University of Missouri-Columbia have found out that warmer ocean temperatures result to a 20.3 percent increase in EF-2 to EF-5 tornadoes in the country. The scientists were able to come up with such conclusion after looking into data about 56,457 tornadoes that happened between 1950 and 2011.
Cooler temperatures in the Pacific led to developments of tornadic events in Indiana, Illinois, Alabama, and Tennessee. Meanwhile, when sea surface temperatures were higher than average, the tornadoes tend to rush through the Midwest, usually to the north and the west of the tornado alley, an area in the U.S. that is often tracked by tornadoes compared to other states.
The study by Lauren McCoy, graduate student of the School of Natural Resources at MU, and Tony Lupo, atmospheric chairperson of the College of Agriculture, Food and Natural resources in the same university, was presented at the annual meeting of the National Weather Association.
"Differences in sea temperatures influence the route of the jet stream as it passes over the Pacific and, eventually, to the United States. Tornado-producing storms usually are triggered by, and will follow, the jet stream. This helps explain why we found a rise in the number of tornados and a change in their location when sea temperatures fluctuated," explained McCoy through a statement via the News Bureau of MU.
According to the experts, they looked into what is known as the Pacific Decadal Oscillation and its relationship to tornadoes. PDO, as its name suggests, are climatic events lasting for two to three decades. Using the PDO data, scientists were able to reconstruct its phases to as far back as the 17th century.
"PDO cool phases are characterized by a cool wedge of lower than normal sea-surface ocean temperatures in the eastern Pacific and a warm horseshoe pattern of higher than normal sea-surface temperatures extending into the north, west and southern Pacific. In the warm phase, which lasted from 1977 to 1999, the west Pacific Ocean became cool and the wedge in the east was warm," McCoy explained.
The authors of the study aim to come up with a research that will help authorities with budget planning for tornado relief. In 2011 alone, hundreds of people died because of tornadoes that resulted to almost $30 billion in damages.
