Atmospheric rivers are warm corridors of tropical moisture that travel through the atmosphere, causing extreme weather conditions when they make landfall. A recent study from the Lawrence Berkeley National Laboratory found that California experienced nine consecutive atmospheric river events during the 2022 and 2023 winter, the longest continuous period of such events in 70 years. These storms led to flooding, power outages, and landslides across the state. Scientists predict that these atmospheric rivers, or “rivers in the sky,” are likely to become more intense and occur in closer succession due to rising temperatures caused by climate change.
Researchers at the Lawrence Berkeley National Laboratory set out to study the phenomenon of more intense atmospheric rivers occurring in quick succession. They found that as temperatures rise, the moisture content in the air increases, leading to more frequent and severe atmospheric river events. By understanding the mechanisms behind these events, scientists hope to help California better prepare for the extreme weather they bring. The study, published in Communications Earth and Environment, highlights the importance of developing strategies to mitigate the impact of atmospheric rivers, as they are expected to become more common in the future.
The study found that dense clusters of atmospheric river events, occurring in a relatively short period of time, are more likely to result in intense rainfall and cause significant damage. The researchers analyzed how the density of atmospheric rivers affects the recovery time of the land, noting that when clusters occur close together, there is little time for the land to recover between events. Additionally, the study identified factors such as pressure and wind conditions that contribute to the formation of these dense clusters, indicating that these events are influenced by a combination of atmospheric conditions.
Prior to the recent pattern of intense rainfall brought by atmospheric rivers, California had been experiencing prolonged drought conditions. The end of the drought in 2023 was followed by a series of atmospheric river events that caused widespread flooding and other damage across the state. The researchers found that the impact of these events was more severe when they occurred in dense clusters, highlighting the need for effective preparation and response strategies. As global warming continues, the study predicts that atmospheric rivers are likely to increase not only in California but also in other regions of the United States.
The findings of the study underscore the urgency of addressing the impacts of atmospheric rivers in the face of climate change. As these events become more frequent and intense, it is essential for policymakers, emergency response teams, and communities to be better prepared for the challenges they pose. With the continued threat of extreme weather events like atmospheric rivers, proactive measures must be taken to protect lives, infrastructure, and ecosystems from the growing risks associated with a changing climate. Scientists and policymakers must work together to develop sustainable solutions that mitigate the impacts of atmospheric rivers and other climate-related challenges.
