As the climate crisis worsens in East Asia, ‘Sky rivers’ will become a greater threat to East Asia.

Atmospheric rivers – narrow bands transporting large volumes of moisture in the air – are becoming more common in mountainous regions such as the Japanese Alps, causing record-breaking precipitation events.

This warning is based on a study done at the University of Tsukuba in Japan. The research team modeled how current patterns would change in the future using historical trends and a future scenario where global-mean surface temperature increases by 4 degrees. 

Focusing on what some have termed ‘sky rivers’, which have caused a number of extreme weather events in East Asia over the last decade, results showed that as global temperatures climb so too will the prevalence of these bands of water. Their impact on societies and economies will increase, in turn. 

This is due in part to the way that atmospheric rivers behave. These rivers carry large amounts of water in the air. Problems arise when they meet obstacles, such as a mountain range. This is when the phenomenon becomes precipitation, which can drop large amounts of precipitation over a small area. This increases the risk of flooding and other disasters. 

‘To investigate the behaviour of atmospheric rivers and extreme precipitation over East Asia under projected climate warming, we used high-resolution global atmospheric circulation model simulations as well as regional climate model downscaling simulations,’ said Professor Yoichi Kamae, first author of the study.

‘We compared simulations based on historical meteorological data from 1951 to 2010 with future simulations based on the year 2090 under a climate scenario with four degrees Celsius of warming of the global-mean surface air temperature,’ he explained. 

At the moment, atmospheric rivers are most commonplace in Japan. The highest extreme rainfall events have occurred on the slopes the Alps. Taiwan, the Korean Peninsula and the north-east China have also been impacted. Future simulations will predict higher levels water vapour transport, more super-precipitation and record breaking downpours. 

In Similar news, last week Germany’s Potsdam Institute for Climate Impact Research and Mercator Research Institute on Global Commons and Climate Change released a joint study that shows a direct link between the number of localised rainy days and regional economic performance. 

Photo credit: Leo Mendes