Mixed Signals From the Stable Isotope Composition of Precipitation and Plant Waxes in the Northern Tropical Andes

Pérez‐Angel, Lina C.; Sepúlveda, Julio; Montes, Camilo; Smith, J.; Molnár, Péter; González‐Arango, Catalina; Snell, Kathryn E.; Dildar, Nadia

doi:10.1029/2022jg006932

Cited by 4 publications

(3 citation statements)

References 101 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We applied an additional filter and retained stations with at least 12 consecutive observations (i.e. one year) to minimize the influence of precipitation seasonality (Pérez-Angel et al, 2022). Several stations, like the Quito-Inamhi station, contained more than 12 consecutive observations.…”

Section: Contemporary δD P From Gnipmentioning

confidence: 99%

“…The surface uplift of the Western Cordillera may have left an imprint on precipitation isotopes through Rayleigh distillation, where precipitation isotopes become more depleted as elevation increases and temperature decreases (Rowley and Garzione, 2007). Therefore, disentangling signals of surface uplift and atmospheric circulation in this region is challenging (Pérez-Angel et al, 2022). We address the influence of elevation change on precipitation isotopes by analyzing the contemporary relationship between precipitation isotopes, elevation, and the Choco jet from the Global Network of Isotopes in Precipitation (GNIP) (Aggarwal et al, 2007) along the Western Cordillera of the Andes.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Plio-Pleistocene evolution of westerly moisture transport into the northern tropical Andes

Fastovich,

Bhattacharya,

Pérez-Ángel

et al. 2024

Preprint

View full text Add to dashboard Cite

Westerly winds from the eastern equatorial Pacific direct moisture into the Western Cordillera of the northern tropical Andes, where subsequent orographic lifting creates the wettest regions in the world. The Choco low-level jet is emblematic of broader westerly winds in this region and is projected to weaken by the end of the 21st century, but climate models show considerable disagreement about the extent of weakening. Using contemporary observations, we demonstrate that the configuration of westerly winds in the eastern equatorial Pacific is reflected by hydrogen isotopes in precipitation (δDp ) in Ecuador. As westerly winds strengthen, δD p increases from greater transport of enriched δD vapor from the Eastern Pacific Warm Pool. We apply this framework to a new record of reconstructed δDp using leaf waxes in ocean sediments off the coast of Ecuador (ODP1239, 0 ◦ 40.32 0 S, 82 ◦ 4.86 0 W) that span the Plio-Pleistocene. Low δD p in the early Pliocene indicates weak westerly water vapor transport in a warmer climate state, which is attributed to a low sea surface temperature gradient between the cold tongue and off-equatorial regions in the eastern equatorial Pacific. Near the end-Pliocene (˜3 Ma), westerly water vapor transport weakens, possibly from shifts in the Intertropical Convergence Zone, forced by high latitude Northern Hemisphere cooling. In complementary isotope-enabled climate simulations, a weak Choco jet and westerly water vapor transport in the early Pliocene are matched by a decrease in δD p and hydroclimate changes in the northern tropical Andes. Precipitation from the Choco jet can cause deadly landslides and weakened westerly winds in the early Pliocene implies a southward shift of these hazards along the Pacific coast of the northern tropical Andes in the future.

show abstract

Section: Contemporary δD P From Gnipmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Plio-Pleistocene evolution of westerly moisture transport into the northern tropical Andes

Fastovich,

Bhattacharya,

Pérez-Ángel

et al. 2024

Preprint

View full text Add to dashboard Cite

show abstract

“…As n-alkanes retain the δ 2 H values established at the time of biosynthesis (Sachse et al, 2012), the average δ 2 H wax of single leaves can be biased toward growth water values available at the early stages of leaf growth (Sachse et al, 2010(Sachse et al, , 2015Tipple and Pagani, 2013;Gamarra and Kahmen, 2017). This may be caused by the timing of leaf synthesis (e.g., early growth often relies on synthates stored at the end of the previous year; Gao et al, 2015;Newberry et al, 2015;Freimuth et al, 2017) and, more generally, changes in the biosynthetic water pool linked to external factors such as temperature and relative humidity (Hou et al, 2008;Kahmen et al, 2008;Zhou et al, 2011;Douglas et al, 2012;Gao et al, 2014b;Bai et al, 2019;Jacob et al, 2021;Eensalu et al, 2023), light intensity (Yang et al, 2009), salinity (Ladd and Sachs, 2012;He et al, 2017;Ceccopieri et al, 2021;Wang et al, 2022), seasonality (Sessions, 2006;Pedentchouk et al, 2008;Kahmen et al, 2011;Newberry et al, 2015;Liu et al, 2017), elevation (e.g., Pérez-Angel et al, 2022) and precipitation δ 2 H (δ 2 H p ; Sachse et al, 2006Sachse et al, , 2010Sachse et al, , 2012Liu and Yang, 2008;Rao et al, 2009;Feakins and Sessions, 2010).…”

Section: Stable Isotopic Compositionmentioning

confidence: 99%

Leaf wax n-alkane distribution and hydrogen isotopic fractionation in fen plant communities of two Mediterranean wetlands (Tenaghi Philippon, Nisí fen—Greece)

Ardenghi,

Mulch,

McFarlin

et al. 2024

Front. Earth Sci.

View full text Add to dashboard Cite

Many continental paleoclimate archives originate from wetland sedimentary sequences. While several studies have investigated biomarkers derived from peat-generating vegetation typical of temperate/boreal bogs (e.g., Sphagnum), only scant information is available on emergent plants predominant in temperate/subtropical coastal marshlands, peri-lacustrine and fen environments. Here, we address this gap, focusing on two wetlands in the Mediterranean (Nisí fen and Tenaghi Philippon, Greece). We examined the concentration, homologue distribution, and hydrogen stable isotopic composition (δ2H) of leaf wax n-alkanes in 13 fen plant species, their surrounding soil, and surface water during the wet growing season (spring) and the declining water table period (summer). Our findings indicate that local graminoid species primarily contribute to the soil n-alkane signal, with a lesser influence from forbs, likely owing to differences in morphology and vegetation structure. The δ2H values of surface and soil water align with local average annual precipitation δ2H, reflecting winter-spring precipitation. Consistently, the average δ2H of local surface, soil, and lower stem water showed negligible evaporative enrichment, confirming minimal 2H-fractionation during water uptake. We find that δ2H values of source water for wax compound synthesis in local fen plants accurately mirror local annual precipitation. Furthermore, despite differences between leaves and lower stems in n-alkane production rates, their δ2H values exhibit remarkable similarity, indicating a shared metabolic substrate, likely originating in leaves. Our net 2H-fractionation values (i.e., precipitation to leaf n-alkanes) align with those in Chinese highlands and other similar environments, suggesting consistency across diverse climatic zones. Notably, our data reveal a seasonal decrease in the carbon preference index (CPI) in plant samples, indicating wax lipid synthesis changes associated with increased aridity. Additionally, we introduce a new parity isotopic difference index (PID) based on the consistent δ2H difference between odd and even n-alkane homologues. The PID demonstrates a strong anticorrelation with plant CPI, suggesting a potential avenue to trace long-term aridity shifts through δ2H analysis of odd and even n-alkane homologues in sedimentary archives. While further development of the PID is necessary for broad application, these findings highlight the intricate interplay between plant physiology, environmental parameters, and sedimentary n-alkanes in unravelling past climatic conditions.

show abstract

Large-scale sea surface temperature gradients govern westerly moisture transport in western Ecuador during the Plio-Pleistocene

Fastovich,

Bhattacharya,

Pérez-Ángel

et al. 2024

Earth and Planetary Science Letters

View full text Add to dashboard Cite

Mixed Signals From the Stable Isotope Composition of Precipitation and Plant Waxes in the Northern Tropical Andes

Abstract: The dependence of the stable isotope composition of meteoric waters on elevation has been used as a tool in paleoaltimetry to reconstruct past surface elevations (e.g.,

Cited by 4 publications

References 101 publications

Plio-Pleistocene evolution of westerly moisture transport into the northern tropical Andes

Plio-Pleistocene evolution of westerly moisture transport into the northern tropical Andes

Leaf wax n-alkane distribution and hydrogen isotopic fractionation in fen plant communities of two Mediterranean wetlands (Tenaghi Philippon, Nisí fen—Greece)

Large-scale sea surface temperature gradients govern westerly moisture transport in western Ecuador during the Plio-Pleistocene

Contact Info

Product

Resources

About