Early summer precipitation in the lower Yangtze River basin for AD 1845–2011 based on tree-ring cellulose oxygen isotopes

Increased Variability of Thailand's Chao Phraya River Peak Season Flow and Its Association With ENSO Variability: Evidence From Tree Ring δ18O

“…The sliding correlation analysis between ENSO and our reconstructed CPRPF shows generally strong correspondence for the period 1854–2005, but weakening between 1921–1960 and 1831–1860 when the CPRPF and ENSO variances were both low (Torrence & Webster, , Figures 3a, 3c, and 3d). The observed CPRPF is positively correlated over the entire CPR basin (Figure S4), which suggests a regional‐scale response to ENSO that is consistent with previous studies (D'Arrigo et al, ; Liu et al, ; Xu et al, ; Xu, Shi, et al, ; Xu, Zheng, et al, ). Specifically, Xu, Pumijumnong, et al () showed that ENSO affects the rainy season precipitation in the central part of the CPR basin and suggested that the reduction in the ENSO‐precipitation relationship between 1930 and 1970 corresponds to the reduced ENSO variance.…”

A tree-ring δ18O based reconstruction of East Asia summer monsoon over the past two centuries

“…Negative relationships between precipitation and tree-ring cellulose δ 18 O levels are reported frequently in monsoonal areas [28,29,30,31]. Precipitation affects tree-ring cellulose δ 18 O mainly via relative humidity and δ 18 O in the precipitation itself.…”

“…EASM reconstruction was conducted by a simple linear regression model on the basis of a split calibration-verification procedure that was designed to test the model reliability [46]. A Fig 1. (a) Locations of the tree-ring sampling sites (circle), the meteorological station (star) and the other tree-ring δ 18 O based precipitation reconstructions (square) [30,31]; background colors represent the spatial correlations between the observed EASM index [33] and CRU TS4.03 precipitation (from June to August); the black box highlights the study area; (b) The observed EASM index from 1948 to 2014.…”

“…Precipitation δ 18 O is negatively correlated with precipitation amounts due to the "amount effect" in the tropical monsoon environment [24,25,26,27]. Therefore, oxygen isotope records preserved in treering cellulose are potential archives of robust monsoonal hydroclimate signals in many warmhumid regions [28,29,30,31,32]. Moreover, the tree-ring δ 18 O preserve long-term climate trends, since it does not require trend removal, in contrast to tree-ring width data.…”

Warm-season hydroclimate variability in Central China since 1866 AD and its relations with the East Asian Summer Monsoon: evidence from tree-ring earlywood width

“…Therefore, hydroclimate reconstructions within the representative region of EASM are necessary. Numerous studies have indicated that tree-ring width mainly reflects temperature signals in the humid and semi-humid EASM core region (Cai and Liu, 2016;Duan et al, 2012;Shi et al, 2017;Shi et al, 2010;Zheng et al, 2012), and suggested the use of tree-ring stable isotopes to capture hydroclimate signals (Cai et al, 2018;Liu et al, 2017a;Xu et al, 2016;Xu et al, 2018). However, robust 15 hydroclimate signals can also be extracted from tree-ring width at some low-altitude and well-drained sites as evidenced by several recent studies (Cai et al, 2017;Chen et al, 2016a;Shi et al, 2015).…”