Feakins, Sarah J. , Kirby, Matthew E. , Cheetham, Michael I. , Ibarra, Yadira , Zimmerman, Susan R.H.

Feakins, S. J., Kirby, M. E., Cheetham, M. I., Ibarra, Y. and Zimmerman, S. R. H.: Fluctuation in leaf wax D/H ratio from a southern California lake records significant variability in isotopes in precipitation during the late Holocene, Organic Geochemistry, 66, 48–59, doi:10.1016/j.orggeochem.2013.10.015, 2014.

Agilent 6890 GC, pyrolysis at 1440C, Thermo Scientific DeltaV Plus

SASM precipitation that falls on the Altiplano is ultimately derived from Atlantic Ocean moisture that has been transported across the Amazon Basin and lifted over the eastern cordillera of the Andes. Altiplano ?Dp thus integrates upstream effects including rainout and moisture recycling over the Amazon Basin, altitude effects associated with upslope moisture transport, and local effects such as the intensity of precipitation (?amount effect?) (Dansgaard, 1964). ... "Increased rainout along this trajectory, as well as increased local precipitation in the Andes, results in more depleted ?Dp, consistent with the continentality and amount effects that dominate ?Dp variability throughout most of tropical South America (Vuille et al., 2003). Accordingly, the intensity of the SASM is significantly negatively correlated with ?18O (and correspondingly ?D) of modern precipitation in the Cen- tral Andes, as well as throughout much of southern tropical South America (Vuille and Werner, 2005).

South American Summer Monsoon precipitation intensity

Results from both observational and modeling studies suggest that the dominant control on modern interannual Andean ?Dp variability is Rayleigh-type fractionation during rainout along the trajectory of moist air masses across the Amazon Basin up to the Andes (e.g., Rozanski et al., 1993; Hoffmann et al., 2003; Vimeux et al., 2005; Vuille and Werner, 2005). Increased rainout along this trajectory, as well as increased local precipitation in the Andes, results in more depleted ?Dp, consistent with the continentality and amount effects that dominate ?Dp variability throughout most of tropical South America (Vuille et al., 2003).