New research has looked at the vast climate “teleconnections” that span across our planet, potentially linking droughts and driving wildfires around the world.
Teleconnection is the idea in atmospheric science that climate and weather events in geographically distant places can be tightly related. After all, the planet is a vast interconnected system.
A freakishly heavy period of rain, for example, could be linked to another downfall miles upon miles away on a different continent. These cross-continental links are often the product of patterns in sea surface temperature or atmospheric pressure variations that swing from season-to-season or even over decades.
Two new studies released this year have explored this concept, with one looking at wildfires and the other at record-breaking rainfall events.
As reported in the journal Advances in Atmospheric Sciences, scientists worked out that the devastating deluges of record rainfall in September 2021 that hit both Northwest India and North China were closely linked through teleconnection patterns.
The rain in this period was 4.1 and 6.2 times standard deviation higher than typical levels in the two regions, respectively, causing a massive amount of damage to infrastructure and human life. It was especially unexpected as the rainy season is generally in July and August, which is typically followed by drier weather.
The researchers found that the western-flowing upper-tropospheric jet streams in Asia were displaced towards the North Pole as they glided into West Asia. In turn, an anomalous cyclone appeared over India, resulting in abundant water vapor hovering into Northwest India that drove the heavy rainfall there.
Likewise, a high-altitude wind stream over the Eurasian continent also meant the conditions in Northwest India contributed to the heavy rainfall in North China.
"Climate extremes in one region can be related to, or lead to, those in other regions, through atmospheric teleconnection patterns. The more frequent and stronger climate extremes expected under global warming will trigger these atmospheric teleconnections to occur more often, which in turn could induce climate extremes in far-away regions worldwide," Riyu Lu, lead author of the study and a professor at the Institute of Atmospheric Physics of the Chinese Academy of Sciences, said in a statement.
A second paper, published in the journal Nature Communications last month, has detailed the teleconnection patterns between wildfires. They measured the amount of land burned around the world between 1982 to 2018 and found distant regions of the world had significant synchronous, or predictably lagged, outbursts of droughts and wildfires.
In other words, there are parts of the world – such as North Africa, the Sahara, southern Africa, the Andes, and northern Australia – that are more likely to experience harmonized droughts with each other and, in turn, synchronized wildfires.
All together, the study estimates that these trans-continental weather patterns account for around 53 percent of the planet’s burned area each year.
“They are a kind of complex butterfly effect, in that things that are occurring in one place have many derivatives very far away,” Sergio de Miguel, an ecosystem scientist at Spain’s University of Lleida and the Joint Research Unit CTFC-Agrotecnio in Solsona, told Science News.