In California, increased wildfire activity has been linked to decreasing snowpack and earlier snowmelt. Not only has this translated into a longer fire season, but reduced snowpack has cascading effects that impact streamflow, water supplies, agricultural productivity, and ecosystems. California receives 80% of its precipitation during the winter, so mountain snowpack plays a critical role in replenishing the state’s water supply.
One factor that affects the amount of winter precipitation (and therefore snowpack) in California is the North Pacific Jet (NPJ)—a current of strong, high altitude winds that occur over the northern Pacific Ocean. Winters when the NPJ is located further north than normal are drier than average in California, while winters when the NPJ is located further south are wetter. Climate change is expected to cause the position of the NPJ to become more variable, which could greatly influence California’s water resources and ecosystems.
The goal of this project is to identify the relationship between the NPJ and wildfires in California. Researchers will first use tree-ring data to examine variability in the position of the NPJ over the past 400+ years to identify historical trends. They will then use historical fire data to determine how the NPJ has influenced wildfire patterns in the past. Finally, researchers will look at recent fire data to see if this historical relationship between the NPJ and fire holds true in the 21 st century.
By documenting the relationship between the NPJ and wildfires, this project will enable fire managers to better forecast future fire conditions, based on projected trends in the NPJ. Improving forecasting ability is critical to successful fire preparedness and accurate anticipation of fire suppression budgets.
