Temperature Variability in Northeast China over the Past Two Millennia
and Linkages with the Arctic Oscillation
Abstract
Temperature reconstruction over the past two millennia has created a
crucial database for global networks and for evaluating and predicting
global climate change. Here, we present a high-resolution
(~5-25 years) temperature reconstruction over the past
2000 years using branched glycerol dialkyl glycerol tetraethers
(brGDGTs) from laminated sediments in a crater lake located in Northeast
China. The brGDGT-derived proxies accurately represented the
month-above-freezing temperatures (MAFT) within our study region. Our
temperature reconstruction exhibited distinct decadal-to-centennial
variability and showed rough correspondence with the AO/NAO index and
solar activity. Furthermore, the spectral analysis identified two
quasi-periodicities of 55-57 and 66-67 years within the MAFTs time
series at a 99% confidence level, suggesting possible associations with
solar activity. These findings imply that long-term temperature
variability in Northeast China is mainly regulated by a combination of
the AO, NAO, and solar activity.