Warmer planet temperatures could cause longer-lasting weather patterns

"In this research, we're trying to see if increased carbon dioxide in the atmosphere and the resulting atmospheric warming will affect the onset and duration of future blocking events," said Tony Lupo, professor and chair of the atmospheric science department at the MU College of Agriculture, Food and Natural Resources. "We're hoping that the research will add cues that could help fellow forecasters better predict blocking and warn people in cases of long-lasting, severe weather."

Atmospheric blocking occurs between 20-40 times each year and usually lasts between 8-11 days, Lupo said. Although they are one of the rarest weather events, blocking 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 and, because they cover a large area, fronts behind them are blocked. Lupo believes that heat sources, such as radiation, condensation, and surface heating and cooling, have a significant role in a blocking's onset and duration. Therefore, planetary warming could increase the frequency and impact of atmospheric blocking.

"It is anticipated that in a warmer world, blocking events will be more numerous, weaker and longer-lived," Lupo said. "This could result in an environment with more storms. We also anticipate the variability of weather patterns will change dramatically over some parts of the world, such as North America, Europe and Asia, but not in others."

Lupo, in collaboration with Russian researchers from the Russian Academy of Sciences, will simulate atmospheric blocking using computer models that mirror known blocking events, then introduce differing carbon dioxide environments into the models to study how the dynamics of blocking events are changed by increased atmospheric temperatures. The project is funded by the US Civilian Research and Development Foundation -- one of only 16 grants awarded by the group this year. He is partnering with Russian meteorologists whose research is being supported by the Russian Federation for Basic Research.

Lupo's research has been published in several journals, including the Journal of Climate and Climate Dynamics. He anticipates that final results of the current study will be available in 2011.