Jul 26, 2017

Multi-year predictability of climate, drought, and wildfire in southwestern North America

Yoshimitsu Chikamoto, Axel Timmermann, Matthew J. Widlansky, Magdalena A. Balmaseda, Lowell Stott
Scientific Reports
  • States that past severe droughts over North America have led to massive water shortages and increases in wildfire frequency
  • States that multiple triggering sources for multi-year droughts in this region translate to difficulty predicting the onset and length of such droughts on multi-year timescales
  • Presents results from a new multi-year dynamical prediction system that exhibits a high degree of skill in forecasting wildfire probabilities and drought for 10–23 and 10–45 months lead time, which extends far beyond the current seasonal prediction activities for southwestern North America
  • Uses a state-of-the-art earth system model along with 3-dimensional ocean data assimilation and prescribes the external radiative forcings to simulate the observed low-frequency variability of precipitation, soil water, and wildfire probabilities in close agreement with observational records and reanalysis data
  • Finds that the underlying source of multi-year predictability can be traced back to variations of the Atlantic/Pacific sea surface temperature gradient, external radiative forcings, and the low-pass filtering characteristics of soils