A 120-year seasonally resolved speleothem record of precipitation seasonality from southeastern China. (15th July 2021)

• Record Type: Journal Article
• Authors: Lu, Jiayu; Zhang, Haiwei; Li, Hanying; Sha, Lijuan; Zhao, Jingyao; Li, Youwei; Wang, Jian; Dong, Xiyu; Edwards, R. Lawrence; Qian, Zhi; Cheng, Hai
• Is Part Of: Quaternary science reviews. Volume 264(2021)
• Publication Date: 2021-07-15
• Subjects: Speleothem δ18O -- Southwestern China -- Precipitation seasonality -- El Niño/Southern Oscillation -- Drought events -- Tripole pattern; Geology, Stratigraphic -- Quaternary -- Periodicals; Stratigraphie -- Quaternaire -- Périodiques; 551.79
• DOI: 10.1016/j.quascirev.2021.107023
• Languages: English
• ISSNs: 0277-3791

Abstract

Abstract: Speleothem oxygen isotope (δ 18 Os ) record as a climatic proxy in southeastern China is still in debate due to multifaceted influencing factors, a modern δ 18 Os record, which can be calibrated or compared with observational data, is critical to explore the interpretation of δ 18 Os proxy. Here we present a seasonally resolved δ 18 Os record spanning the interval of 1898–2018 CE from Niubi Cave, Guangdong Province, southeastern China. A comparison between the Niubi δ 18 Os and instrumental data reveals that the Niubi δ 18 Os variability is primarily controlled by changes in precipitation seasonality modulated by El Niño-Southern Oscillation on interannual to interdecadal timescales. Higher (lower) δ 18 Os values correspond to lower (higher) ratios of the East Asian summer monsoon/non-summer monsoon precipitation during the El Niño (La Niña) events associated with concomitant changes in the outgoing longwave radiation, wind field and Western Pacific Subtropical High. While ∼73% historical drought events correlate to positive anomalies in Niubi δ 18 Os values over the last 120 years, the rest of drought events associate with the negative δ 18 Os anomalies. This observation suggests two different mechanisms for the drought events with more and less diminution of rainfall amount in the East Asian summer monsoon relative to the non-summer monsoon precipitation, respectively. Additionally, our Niubi δ 18 Os record from southeastern China, together with other high-resolution speleothem and tree ring records, demonstrate a "tripole pattern" of summer precipitation during the last ∼100 years in eastern China. Highlights: δ 18 Os records from SEC is controlled by the precipitation seasonality modulated by the ENSO on interannual timescales. Not all drought events correspond to the higher δ 18 Os in NB cave because of the effect of precipitation seasonality. A "tripole pattern" of summer rainfall in eastern China can be observed in palaeoclimatic records over the past ∼100 years.