Author ORCID Identifier
https://orcid.org/0000-0001-5401-7148
Date of Award
Summer 2026
Document Type
Thesis (Master's)
Department or Program
Earth Sciences
First Advisor
Erich Osterberg
Second Advisor
Meredith Kelly
Third Advisor
Christopher Guiterman
Abstract
Southeastern Siberia (SES) is the most active wildfire region within the circumboreal zone, releasing aerosols that influence atmospheric composition, climate, and public health. SES burning is projected to increase this century as high-latitude regions continue to warm rapidly, but these projections are poorly constrained by historical climate–fire relationships due to uncertainties in SES fire history prior to the satellite era. Here we present a 1,200-year reconstruction of SES wildfire activity based on black carbon (BC) preserved in the Begguya (Alaska) ice core. The record reveals large and persistent shifts in fire activity linked to seasonal climate conditions. Elevated burning from 800–1415 CE coincided with warm late winter temperatures and a strengthened East Asian summer monsoon, suggesting that earlier snowmelt and longer premonsoon dry periods promoted widespread spring burning despite wetter summers. Fire activity declined abruptly beginning at 1415 CE during the onset of colder Little Ice Age conditions, interpreted to reflect delayed snowmelt and shortened spring fire seasons. Burning partially rebounded after 1525 CE during intervals of weakened monsoonal precipitation and enhanced summer drought. The close correspondence between Begguya BC and independent paleoclimate reconstructions is consistent with climate, rather than land use, being the primary control on SES fire regimes over the last millennium. Since the mid-19th century, BC concentrations have increased to near the highest levels of the last millennium, suggesting that continued winter and spring warming may drive future SES burning to surpass historical levels.
Recommended Citation
Chalif, Jacob I., "Seasonal climate drivers of southeastern Siberian fire over the last 1,200 years from the Begguya (Alaska) ice core" (2026). Dartmouth College Master’s Theses. 317.
https://digitalcommons.dartmouth.edu/masters_theses/317
