Model evaluation of the coherence of a common source water oxygen isotopic signal recorded by tree-ring cellulose and speleothem calcite

Abstract

O records of the two proxies. When the former is higher than or comparable with the latter, finding one to one correspondence between the d 18 O records of the two proxies could be challenging. Modeling exercise revealed a favorable climatic condition at Jagdalpur (19.08 N, 82.03 E), a potential tropical location for tree ring and speleothem-based climate reconstruction, for inheriting a common source water d 18 O signal in both the proxies. d 18 O records of tree ring and annually resolved speleothem from Jagdalpur could be integrated for the multiproxy climate reconstruction.

Employing stable isotopes to determine the residence times of soil water and the temporal origin of water taken up by Fagus sylvatica and Picea abies in a temperate forest

“…However, comparable mechanistic insight into what determines variability in the isotope composition of a plant's source water does not exist. The approximation of a plant's source water d 2 H and d 18 O from precipitation isotope databases, such as the Global Network of Isotopes in Precipitation (GNIP) database (Kanner et al, 2013;Managave, 2014;Dee et al, 2015), or derived products, such as the Online Isotope Calculator for Precipitation (OIPC) (Bowen & Wilkinson, 2002;Richter et al, 2008), is therefore still difficult and can introduce large uncertainties, for example in the interpretation of H and O isotopes in tree ring records and leaf wax lipids.…”

The δD records of n-alkane and n-alkanoic acid of tropical trees reflect δD of precipitation during the early stages of the leaf growth

“…The values of 𝑒 𝑖 were estimated from the leaf temperature. Boundary layer conductance was considered as 1 mol m -2 s -1 (Roden et al, 1999;Managave et al, 2014). Tipple et al, (2015) showed the utility of the Craig-Gordon model in modeling δD values of n-alkanes.…”

“…The isotopic composition of the leaf water calculated using Equation 1 is sensitive mainly to (i) leaf temperature, (ii) relative humidity, (iii) isotopic composition of the xylem water (i.e. source water) and atmospheric water vapor (Sachse et al, 2009;Managave, 2014).…”

Impacto das mudanças climáticas nos últimos 500 anos por meio de estudos dendroclimatológicos e isotópicos de árvores na região do Parque Nacional Cavernas do Peruaçu

“…The subfossil samples found in the caves (Figure S16) radiocarbon ( 14 C) dates were wiggle matched against the Southern Hemisphere calibration curve [59][60] , and indicated an overlap of two A. cearensis during the Little Ice Age (LIA) . Then, synchronization of this tree-ring δ 18 O floating record with local speleothem δ 18 O series, that share a common source water δ 18 O signal 41 and have similar inter-annual and decadal variability in the recent decades (Figure S12, and S19), pointed out a position of significant correlation between records from 1527 to 1690 (r = 0.34 p < 0.01, Figure S19). During this period, and similar to recent years, climate model simulations for the site (CESM-LME) show a temperature increase (Figure 6A), a decrease in relative humidity (Figure 6B) and small decrease in precipitation (Figure 6C).…”

“…Tree-ring widht and growth are intimately coupled to regional climate 37,38 . Local and global climate can also affect the stable oxygen isotope ratios (δ 18 O) in tree rings, offering an additional proxy to improving cross-dating, understanding tree physiological responses, enhancing climate signal intensity, spatial coverage [39][40] , and enabling comparison with other archives 41 . Trees absorb water from rainfall with an δ 18 O signal determined by the temperature of condensation, which have little variation in tropical lowlands, and the amount of rainfall, both local or upstream 42 .…”