COLUMBIA, Mo. – Atmospheric blocking is a relatively unknown weather phenomenon responsible for prolonged bouts of extreme conditions, such as the summer 2011 Midwest heat wave that led to destructive wildfires in Texas. Now, University of Missouri researchers will collaborate with the A.M. Obukhov Institute of Atmospheric Physics of the Russian Academy of Sciences in a 3 million Russian ruble (about $104,000) project to understand and predict blocking patterns.
"Atmospheric blocking occurs when a high pressure system gets stuck in one place," said Tony Lupo, professor and chair of the Department of Soil, Environmental and Atmospheric Sciences in the School of Natural Resources. "If hot, dry weather doesn't move, it can lead to extreme heat and drought conditions. If a rainy pattern becomes stuck, it can lead to flooding."
Atmospheric blocking occurs between 20-40 times each year throughout the world and usually lasts between 8-11 days, Lupo said. Although atmospheric blocking is one of the rarest weather events, it can trigger dangerous conditions, such as a 2003 European heat wave that caused 40,000 deaths. Blocking usually results when a powerful, high-pressure area gets stuck in one place. Because they cover a large area, fronts behind them are blocked.
With the grant, MU researchers will develop new methods for spotting and predicting atmospheric blocking. They also will analyze the social and economic impacts that blocking events caused during the 20th century. By better understanding the effects of blocking and how to identify the weather phenomenon, forecasters and government officials will be able to better prepare communities for extreme weather.
"Blocking events are important because of the effects on people living in affected areas," Lupo said. "Heat waves caused by blocking killed 15,000 people in Russia last year."
Atmospheric blocking has a major effect on the environment and commerce. In 2004, a blocking event over Alaska decreased precipitation and increased temperatures. The heat melted glaciers and, when coupled with decreased precipitation, it caused fierce forest fires in the interior of the state. Blocking can also have positive effects. In 2004, blocking caused prolonged pleasant temperatures and sunny skies leading to excellent crop yields in Missouri. However, a cold snap in spring 2007 caused by blocking killed budding plants.
Lupo has studied atmospheric blocking for more than 20 years and has authored more than 20 scientific papers on the subject. Lupo is a Fellow of the Royal Meteorological Society in London. In 2005, he was named a Fulbright Scholar and spent a summer at the Russian Academy of Sciences working with fellow climate scientists. Lupo is a member of the International Panel of Climate Change that shared the 2007 Nobel Peace Prize with Al Gore.