Authors: Paul Knapp*, University of North Carolina Greensboro, Peter Soule', Appalachian State University, Justin Maxwell, Indiana University, Jason Ortegren, University of West Florida, Joshua Bregy, Indiana University
Topics: Physical Geography, Climatology and Meteorology, Paleoenvironmental Change
Keywords: Tropical Cyclone Precipitation, Volcanic Eruptions, Southeastern United States
Session Type: Poster
Start / End Time: 3:05 PM / 4:45 PM
Room: Lincoln 2, Marriott, Exhibition Level
Presentation File: No File Uploaded
Research during the past decade has documented decreased tropical cyclone activity in the North Atlantic following volcanic eruptive events via sea surface temperature cooling associated with reduced solar radiation receipt. Here we examined relationships between longleaf pine latewood widths and the climatic forcing effect of volcanic eruptions during 1770–2000. We hypothesized that elevated stratospheric aerosol optical depth (SAOD) levels at 550 nm post-eruption would cause reduced tropical cyclone precipitation (TCP), which have high fidelity (r =.71) with longleaf latewood widths. We examined post eruption-year radial growth values for each eruption event (n = 14) that produced SAOD values of ≥ 0.02 (approximately 20% of the maximum Pinatubo eruption) and found that: 1) latewood radial growth decreased by approximately 20% following years with SAOD values ≥ 0.02 for eruptive events (n =7) in the eastern hemisphere, but increased 22% following eruptive events (n =7) in the western hemisphere. Growth differences between groups were significant (p <0.01); 2) mean latewood radial growth values post-eruption events in the eastern hemisphere (0.86) and western hemisphere (1.03) were different (p <0.05) despite no significant differences (p = 0.2) in SAOD values; and 3) the mean duration of elevated SAOD levels was three years for the eastern hemisphere events and 1.43 years for the western hemisphere events. We conclude that latewood growth responses that record TCP amounts along the North Carolina coast may be influenced by the geographic origin of major volcanic eruptive events.