Research

Understanding climate and environmental systems through space and time

My research interests have led me to pursue work focused on paleoenvironmental and climate topics that range from evaluating modern extreme events, to understanding landscape-scale change over millennia. Broadly speaking, my research can be divided into the following themes:

Publications:

Revisiting the Holocene global temperature conundrum

Recent enhanced hydroclimate variability in California

Early Holocene carbonate deposition in the Kenai lowlands, Alaska 

Reconstructing Holocene hydrologic balance in the Kenai lowlands, Alaska

Holocene Arctic sea ice and Pacific circulation

Holocene Aleutian Low and precipitation variability in southern Alaska

Late Holocene human-environment interactions in Morro Bay, CA

Data descriptor of environmental monitoring at Lake Peters, Alaska

In review and preparation: 

1) Using tree rings to study variability in the polar jet stream

Reconstructed summer "wave5" events, shown with the surface temperature anomalies in a composite of 80th percentile or higher values for our wave5 index.
Xu et al., 2022 (EGU Abstract)  - the North Atlantic jet influences climate and societal extremes
Broadman et al., 2022 (AGU Abstract) - summertime Rossby wavenumber5 influenced by ENSO events

2) Analyzing eruption frequency in the Alaska-Aleutian arc using lacustrine tephra deposits

The bright white line is a volcanic ash (tephra) deposit in sediment collected from Sunken Island Lake, in the Kenai Peninsula lowlands.
Bolton et al., 2021 (AGU Abstract)

3) Contextualizing the current Arizona "megadrought" and low river flows

Observed versus predicted Salt River streamflow, reconstructed using tree rings.
Broadman et al., in prep: A multi-century perspective on the response of streamflow in Arizona’s Salt River basin to 21st century megadrought. 
Broadman et al., in prep: Spatial heterogeneity in the response of trees to the 21st century megadrought in the southwestern United States. 

4) Using quantitative wood anatomy to study the impact of heatwaves on trees

High quality image of wood cells from an Engelmann spruce sample from Jasper National Park, British Columbia
Broadman et al., in prep: Multi-proxy analysis of tree rings from Jasper National Park reveals complex response to 2021 heat dome.