Temperature variability in northeastern China over the Past 2000 Years: Linkages with the Arctic oscillation and solar activity

Abstract

Understanding regional paleotemperature changes over the past 2000 years is crucial for global climate networks, as it provides valuable insights into climate dynamics and offers a regional perspective within the global system. In this study, we present a high-resolution temperature reconstruction (∼10-year resolution) for the past two millennia, using branched dialkyl glycerol tetraethers (brGDGTs) from the laminated sediments of Lake Shuanggoushan in Northeast China. Our reconstruction of month-above-freezing temperatures (MAFT) revealed significant temperature variability on decadal to centennial timescales, which aligns well with other paleotemperature records from Northeast China but diverges from the composite temperature series of the broader Chinese region. In this region, instrumental records revealed a strong positive correlation between the Arctic Oscillation (AO) and winter-spring temperatures (Nov–Apr), with a weaker correlation during the ice-free season (May–Oct). Paleoclimate records further demonstrate a weak positive correlation (r = 0.22, p < 0.01) between the AO index and MAFTs on decadal timescales, suggesting that the AO has influenced regional temperature variability over the past 2000 years. Spectral analysis of the temperature time series identified two periodicities (55–57 and 66–67 years) with 99 % confidence, which closely align with the ∼60-year solar cycle. This finding indicated a possible link between temperature variability and solar activity. Overall, our results highlight the significance of the AO and solar activity in driving decadal temperature variability during ice-free seasons in Northeast China over the past two millennia.