Potential Influences of the Madden-Julian Oscillation on Global Wildfire

The Madden-Julian Oscillation (MJO) influences weather-climate events globally. Because of its effects on variables such as temperature, humidity, precipitation, and lightning, the MJO has the potential to affect wildfires in the extratropics as well as the tropics. Wildfires are closely related to meteorological and climatological conditions, but also influenced by the biospheric environment and human activities. This study explored possible MJO effects on the probability of wildfire using products of global data assimilation. Three areas were identified that exhibit strong signals of MJO effects. These areas are southern equatorial Africa, the Amazon Basin, and central western Asia. Four variables were used to measure fire. They are the Nesterov Index which incorporates surface temperature and humidity, the Fire Danger Index which adds the availability of fire fuel to the NI for a more robust estimate of fire threat, burn area; and fire number within a grid box. It is found that these variables fluctuate through the life cycle of the MJO, although their pattern varies over these regions. The results confirm the MJO may influence the probability of wildfires in regions of the world remote to MJO activities and point to the direction of further studies to understand the physical mechanisms for this influence and potential way to harness this information for the prediction of wildfire potential with a lead time beyond two weeks.