Stalled Weather Patterns Will Get Bigger - Due To Climate Change

Climate change will increase the size of stalled high-pressure systems that can cause heat waves, droughts, and other extreme weather, according to a new study.

Climate change will increase the size of stalled high-pressure weather systems called ‘blocking events’ that have already produced some of the 21st Century’s deadliest heat waves, according to a Rice University study.

Atmospheric blocking events are middle-latitude, high-pressure systems that stay in place for days or even weeks.

Depending upon when and where they develop, blocking events can cause droughts or downpours and heat waves or cold spells. Blocking events caused deadly heat waves in France in 2003 and in Russia in 2010.

Using data from two sets of comprehensive climate model simulations, Rice fluid dynamicists ​Ebrahim Nabizadeh and Pedram Hassanzadeh, and colleagues found that the area of blocking events in the northern hemisphere will increase by as much as 17% due to anthropogenic climate change. The study, which is available online from Geophysical Research Letters, was co-authored by Da Yang of Lawrence Berkeley National Laboratory and the University of California, Davis, and Elizabeth Barnes of Colorado State University.

Hassanzadeh, an assistant professor of mechanical engineering and of Earth, environmental and planetary sciences, uses computational, mathematical and statistical models to study atmospheric flows related to a broad range of problems from extreme weather events to wind energy. He said researchers have increasingly been interested in learning how climate change might affect blocking events, but most studies have focused on whether blocking events will become more frequent as the atmosphere warms because of greenhouse gas emissions.