Inter-Research > CR > v79 > n3 > p207-218  
Climate Research

via Mailchimp

CR 79:207-218 (2020)  -  DOI:

Reconstructing summer upper-level flow in the northern Rocky Mountains using an alpine larch tree-ring chronology

Evan E. Montpellier1,*, Peter T. Soulé1, Paul A. Knapp2, L. Baker Perry1

1Department of Geography and Planning, Appalachian State University, Boone, NC 28608, USA
2Department of Geography, Environment, and Sustainability, University of North Carolina at Greensboro, Greensboro, NC 27412, USA
Corresponding author:

ABSTRACT: Mid-latitude mesoscale weather during the climatological summer is strongly influenced by fluctuations in synoptic-scale circulation patterns. Previous research has linked Arctic amplification to alterations in summer synoptic climatology, leading to more extreme weather events in the mid-latitudes. In this study, seasonal (JJA) upper-level (500 hPa) atmospheric flow is reconstructed in the mid-latitudes using an alpine larch Larix lyallii Parl. tree-ring chronology sampled from western Montana. Significant relationships were found between alpine larch radial growth and upper-level flow patterns derived from the North American Regional Reanalysis dataset (1979-2015). Meridional and zonal flows that manifest in ridging are associated with enhanced radial growth of alpine larch (i.e. meridional flow west [r = 0.504, p = 0.001] and zonal flow north [r = 0.642, p < 0.001] of the study site). Meridional and zonal flows associated with troughing result in decreased radial growth (i.e. meridional flow east [r = -0.497, p = 0.001] and zonal flow south [r = -0.584, p < 0.001] of the study site). Using the leave-one-out method, a linear regression model was calibrated and verified between a principal component analysis score derived from measurements of upper-level flow in western North America and alpine larch tree growth. The 444 yr climate reconstruction of summer 500 hPa flow suggests that ridging is becoming more intense over the western United States and Canada since the 1980s.

KEY WORDS: Dendroclimatology · Larix lyallii · Climate reconstruction · Atmospheric flow · Synoptic climatology

Full text in pdf format
Cite this article as: Montpellier EE, Soulé PT, Knapp PA, Baker Perry L (2020) Reconstructing summer upper-level flow in the northern Rocky Mountains using an alpine larch tree-ring chronology. Clim Res 79:207-218.

Export citation
Share:    Facebook - - linkedIn

 Previous article Next article