Every wildfire has a spark but some of the most devastating fires on record may be set in motion thousands of miles away and high above the equatorial oceans. New research reveals that a vast tropical weather system known as the Madden-Julian Oscillation or MJO can trigger dangerous fire conditions from California to Korea. This link between distant storms and wildfires could be key to predicting and addressing disastrous wildfire events.
The Crucial Role of the Madden-Julian Oscillation: Scientists Link Wildfires in California and Other Parts of the Globe to Storm Surges in the Indian Ocean
Background
Climate scientists know that climate variability or changes in weather patterns affect fire activity and even create wildfire risks. However, despite this general understanding, the exact mechanisms by which climate influences fires are still not fully understood.
A study led by Young-Min Yang of Jeonbuk National University in South Korea, in collaboration with an international team of climate scientists, investigated how large-scale tropical climate patterns, particularly the MJO system, influence wildfire activities,
The MJO is a massive and slow-moving system of storm activity near the equator. It is considered a global-scale disturbance of the tropical atmosphere and is characterized by eastward-moving pulses of cloud and rainfall that recur every 30 to 60 days.
It specifically creates bursts of convection or intense thunderstorm activity that sweep eastward across the Indian and Pacific Oceans. These bursts can affect weather patterns far away through atmospheric teleconnections or chain reactions in the atmosphere.
Scientists know that MJO significantly influences global weather patterns, including the timing and strength of monsoons and tropical cyclones, but its impact on wildfires in mid-latitude regions like California, Korea, and Eastern Europe has not been quantified.
Findings
The researchers combined 21 years of satellite fire-emission records, fire-weather indices like the Canadian Fire Weather Index, and global atmospheric reanalysis data to uncover the link between the Madden-Julian Oscillation and wildfires in mid-latitude regions.
Results of the analysis revealed a striking pattern. Up to 20 percent of wildfire events in mid-latitude regions coincided with certain phases of the MJO. These phases typically begin when the core storm activity of MJO clusters over the eastern Indian Ocean.
The fire-prone phases then trigger a chain reaction of atmospheric waves or Rossby waves that alter weather conditions thousands of miles away. These waves travel from the tropics into the mid-latitudes. They often create dry, windy, and low-humidity conditions.
Nevertheless, the aforementioned suggests that the Madden-Julian Oscillation acts as a remote trigger that influences fire-friendly conditions thousands of kilometers away within days to a week. The timing of many wildfires often follows a predictable atmospheric rhythm.
Implications
The August 2020 California Complex Fire and the 2010 Russian wildfires were traced back to strong MJO activity over the Indian Ocean. The record-breaking January 2025 fires in Los Angeles and deadly South Korean wildfires were also traced back to MJO activity.
It is worth mentioning that MJO is already predictable 2-4 weeks in advance with current weather models. The team of Yang is developing an AI-based wildfire forecasting tools which can help in providing forecasts and warnings two to four months in advance.
An accurate early-warning system based on MJO is critical for prepositioning countermeasures such as strategic deployment of firefighting crews, setting up protective measures like vegetation clearing and evacuation plans, and scheduling controlled burns.
It is also important to note that the oceans that fuel the MJO are warming and expanding. A more frequent and stronger MJO could result in more wildfires. This could increase further the global share of wildfires driven by tropical weather events or weather systems.
FURTHER READING AND REFERENCE
- Yang, Y.-M., Lee, D. Y., Park, J.-H., Lee, J.-Y., Yun, K.-S., An, S.-I., Li, T., and Wang, B. 2025. “Global Fire Emissions Linked to Madden-Julian Oscillation.” Advances in Atmospheric Sciences. DOI: 1007/s00376-025-4447-0