Salinity_water (mostly P-E)
Salinity_water (mostly P-E)
Permanent anoxia in the subsurface water confines phytoplankton, dominated by dinoflagellates and diatoms24, to the oxygenated, brackish and deuterium-depleted surface water where their lipid dD values can be expected to closely co-vary with the surface water dDvalues25,26. dD values of that water are controlled by the amount of rainfall, its isotopic composition and the amount of mixing with the underlying sea water. As rain also increases the density stratification in the lakes, decreasing mixing, surface water dD values are expected to be significantly lower during wet periods compared with dry periods.  Zhang and Sachs 2007, Organic Geochemistry, 38: 582-608.
Secondly, plant community changes in the catchment (or other ecological changes) may influence the dD record. Vegetation changes could reasonably have an influence on the mean catchment ewax/precip that lasts for decades, so this mecha- nism might operate too slowly to explain sample-to-sample vari- ability in the sediment, although it may contribute to the multi- decadal variability. We observed abundance variation in homo- logues downcore (Fig. 5), which could be consistent with ecological changes influencing dD values; however, the non-unique chain length distributions of different plant species (Bush and McIner- ney, 2013) make it impossible to draw unique solutions here.
Secondly, plant community changes in the catchment (or other ecological changes) may influence the dD record. Vegetation changes could reasonably have an influence on the mean catchment ewax/precip that lasts for decades, so this mecha- nism might operate too slowly to explain sample-to-sample vari- ability in the sediment, although it may contribute to the multi- decadal variability. We observed abundance variation in homo- logues downcore (Fig. 5), which could be consistent with ecological changes influencing dD values; however, the non-unique chain length distributions of different plant species (Bush and McIner- ney, 2013) make it impossible to draw unique solutions here.
While the isotopic composition of precipitation appears to be the primary control on the structure of the LT ?Dwax record, it is clear that secondary effects also contribute to this signal. Most notably, the much larger range at LT (102h) than at Illimani (58h) over the past 19 kyr suggests the influence of compounding effects on LT ?Dwax, such as decreased regional precipitation, resulting in a more enriched ?Dp, and low local humidity, which would tend to further enrich plant source water by soil water evaporation and/or leaf transpiration. Since such local evapotranspiration feedbacks would be expected to act in step with ?Dp changes, this would serve to amplify the ?Dwax signal and increase its sensitivity to ?Dp variability.
While the isotopic composition of precipitation appears to be the primary control on the structure of the LT ?Dwax record, it is clear that secondary effects also contribute to this signal. Most notably, the much larger range at LT (102h) than at Illimani (58h) over the past 19 kyr suggests the influence of compounding effects on LT ?Dwax, such as decreased regional precipitation, resulting in a more enriched ?Dp, and low local humidity, which would tend to further enrich plant source water by soil water evaporation and/or leaf transpiration. Since such local evapotranspiration feedbacks would be expected to act in step with ?Dp changes, this would serve to amplify the ?Dwax signal and increase its sensitivity to ?Dp variability.
This amount effect lowers the summer precipitation isotopic com- position, dampens the seasonality of the mean precipitation of isotopic values and lowers the integrated annual precip- itation isotopic composition. Hence, in drier years average ?D values will be D-enriched relative to wetter years, and likewise warmer years will be D-enriched relative to colder years (Fig. 4b). Given the low precipitation amounts in this arid region today, the amount effect is likely to remain sec-ondary to the temperature controls on isotopic composition apparent in the seasonal cycle.
This amount effect lowers the summer precipitation isotopic com- position, dampens the seasonality of the mean precipitation of isotopic values and lowers the integrated annual precip- itation isotopic composition. Hence, in drier years average ?D values will be D-enriched relative to wetter years, and likewise warmer years will be D-enriched relative to colder years (Fig. 4b). Given the low precipitation amounts in this arid region today, the amount effect is likely to remain sec-ondary to the temperature controls on isotopic composition apparent in the seasonal cycle.
Physiological differences between plant groups also result in differing ?Dwax values between C3 trees and shrubs and C4 grasses (16), and we use ?13Cwax records to correct for the influence of vegetation change on ?Dwax values (25) (?Dwax-corr, SI Text and Fig. S1).
Physiological differences between plant groups also result in differing ?Dwax values between C3 trees and shrubs and C4 grasses (16), and we use ?13Cwax records to correct for the influence of vegetation change on ?Dwax values (25) (?Dwax-corr, SI Text and Fig. S1).
Physiological differences between plant groups also result in differing ?Dwax values between C3 trees and shrubs and C4 grasses (16), and we use ?13Cwax records to correct for the influence of vegetation change on ?Dwax values (25) (?Dwax-corr, SI Text and Fig. S1).
Physiological differences between plant groups also result in differing ?Dwax values between C3 trees and shrubs and C4 grasses (16), and we use ?13Cwax records to correct for the influence of vegetation change on ?Dwax values (25) (?Dwax-corr, SI Text and Fig. S1).
Physiological differences between plant groups also result in differing ?Dwax values between C3 trees and shrubs and C4 grasses (16), and we use ?13Cwax records to correct for the influence of vegetation change on ?Dwax values (25) (?Dwax-corr, SI Text and Fig. S1).
Physiological differences between plant groups also result in differing ?Dwax values between C3 trees and shrubs and C4 grasses (16), and we use ?13Cwax records to correct for the influence of vegetation change on ?Dwax values (25) (?Dwax-corr, SI Text and Fig. S1).
Changes in d18O values that do not parallel those in Sr/Ca, however, are best explained by changes in water temperature, or in the 18O/16O ratio of precipitation. Changes in the isotopic composition of precipitation may be brought about by shifts in water-vapour source, air temperature (Andrews 1993) or cloud height. Variations in the intensity of monsoon convection may be important, since highly 18O-depleted rainfall is produced by the strong uplift that occurs in monsoon clouds with cold tops (Fontes et al. 1993).
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.
Spero, H.J., Bijma, J., Lea, D.W., Bemis, B.E., 1997. Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390, 497-500.