Development of a Chironomid-based Air Temperature Inference Model for the Central Canadian Arctic

• Published in: Journal of Paleolimnology
• Main Authors: Porinchu, David, Rolland, Nicolas, Moser, Katrina
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Scholarship@Western 2009
• Subjects: Paleolimnology; Chironomids; Inference model; Air temperature; Transfer function; Arctic; Paleoclimate; Midges; Climate change; Geography; Tundra
• Online Access: https://ir.lib.uwo.ca/geographypub/121; https://doi.org/10.1007/s10933-008-9233-3

Subfossil midge remains were identified in surface sediment recovered from 88 lakes in the central Canadian Arctic. These lakes spanned five vegetation zones, with the southern-most lakes located in boreal forest and the northern-most lakes located in mid-Arctic tundra. The lakes in the calibration are characterized by ranges in depth, summer surface-water temperature (SSWT), average July air temperature (AJAT) and pH of 15.5 m, 10.60°C, 8.40°C and 3.69, respectively. Redundancy analysis (RDA) indicated that maximum depth, pH, AJAT, total nitrogen-unfiltered (TN-UF), Cl and Al capture a large and statistically significant fraction of the overall variance in the midge data. Inference models relating midge abundances and AJAT were developed using different approaches including: weighted averaging (WA), weighted averaging-partial least squares (WA-PLS) and partial least squares (PLS). A chironomid-based inference model, based on a two-component WA-PLS approach, provided robust performance statistics with a high coefficient of determination (r 2 = 0.77) and low root mean square error of prediction (RMSEP = 1.03°C) and low maximum bias. The use of a high-resolution gridded climate data set facilitated the development of the midge-based inference model for AJAT in a region with a paucity of meteorological stations and where previously only the development of a SSWT inference model was possible.