Skip to main page content

500 years of past temperatures derived using Blue Intensity from Araucaria araucana in Northern Patagonia, Argentina

My Session Status

15:30, Tuesday 28 Jun 2022 (15 minutes)

Ring-width (RW) and Blue Intensity (BI) parameters (earlywood - EWB, inverted latewood – LWBinv, and delta - DB) were measured from samples of Araucaria araucana from six sites in northern Patagonia, Argentina. The distance between the most southerly and northerly sites is ca. 130 kms. Despite a much weaker between-tree signal for the BI parameters than RW, principal component analysis identifies a much stronger regional between-site signal for the BI parameters. Split period correlation response function analysis (1901-1958 / 1959-2017) of the tree-ring parameters against monthly temperatures, precipitation and PDSI (CRUTS-4) shows an insignificant or unstable coherence with hydroclimate, but a strong stable response between DB and summer mean temperatures. LWBinv also shows a similar temperature response but it is slightly weaker for the earlier period (1901-1958). Regional composite averaging and principal component regression experiments lead to similar reconstructions of past December-March mean temperatures, dominated by the DB parameter, that explain 41-43% of the temperatures. Despite these encouraging results, a weakening in the calibrated signal in recent decades is noted. The reconstruction variants indicate a significant regional ca. 1 oC warming of summer temperatures since the late-19th century and distinct cold years which are coincident with major volcanic eruptions (e.g. 1729, 1815).

My Session Status

Send Feedback

Session detail
Allows attendees to send short textual feedback to the organizer for a session. This is only sent to the organizer and not the speakers.
To respect data privacy rules, this option only displays profiles of attendees who have chosen to share their profile information publicly.

Changes here will affect all session detail pages