Extreme firebrand transport by atmospheric waves in wildfires

In wildfires, burning pieces of wood (i.e. firebrand) are transported downstream by wind. Once they land, these firebrands can start a secondary fire far away from the main fire. This process is referred to as spotting and the secondary fires are called spot fires. In this talk, we first show numerically that atmospheric waves can lead to extremely large spotting distances, sometimes reaching several kilometers. Then we present a dynamical systems theory which explains and quantifies these large spotting distances. In essence, our theory identifies time-dependent trapping regions with relatively high lift which delay the landing of some firebrands.