Identifying the conditions necessary for CONUS fires to impact the Arctic

We present preliminary results from a back-trajectory study aimed at determining the necessary conditions required for a contiguous U.S. fire to impact the Arctic. New regulations for black carbon (BC) currently under consideration by Congress and the EPA could affect management decisions on wildfires and the ability to conduct prescribed burning. Congressional testimony has suggested various mitigation strategies for Arctic BC including shifting the seasonal timing of continental U.S. prescribed burning. However, many questions remain regarding when and how continental U.S. fires contribute to Arctic BC. In particular, what regions, type of fires, timing, and plume injection heights along with transport meteorological patterns are most likely to result in continental U.S. fires affecting the Arctic? To address these questions, we have conducted a 30-year high-resolution back-trajectory study. The data from this study will be coupled with map-typing of the synoptic meteorological patterns required for BC transport. The goal is to determine the type of synoptic meteorological progressions required to allow BC Arctic transport and their frequency of occurrence. While other factors may limit the BC transport to the Arctic (e.g. deposition), this study determines the necessary conditions for BC transport for any given synoptic pattern. Specifically the objectives of this work are to determine the necessary conditions for emissions from a CONUS fire to potentially reach the Arctic based on fire type (e.g. wildfire vs. prescribed), fire location, time-of-year, and smoke plume injection. It can also provide an answer to the corollary question of Arctic impact. What are the times, places, and conditions where CONUS fires have little or no chance of impacting the Arctic? We present preliminary results based on over 10 years of back trajectories.