Sea surface temperatures (SST) and inorganic continental input over the last 25,000 years (25 ka) are reconstructed in the far eastern equatorial Pacific (EEP) based on three cores stretching from the equatorial front (~0.01°N, ME0005-24JC) into the cold tongue region (~3.6°S; TR163-31P and V19-30). We revisit previously published alkenone-derived SST...
Assessing impacts of future anthropogenic carbon emissions is currently impeded by uncertainties in our knowledge of equilibrium climate sensitivity to atmospheric carbon dioxide doubling. Previous studies suggest 3 K as best estimate, 2–4.5 K as the 66% probability range, and non-zero probabilities for much higher values, the latter implying a...
Deciphering the evolution of global climate from the end of the Last Glacial Maximum approximately 19 ka to the early Holocene 11 ka presents an outstanding opportunity for understanding the transient response of Earth's climate system to external and internal forcings. During this interval of global warming, the decay of...
Biogenic opal, organic carbon, organic matter stable isotope, and trace metal data from
a well-dated, high-resolution jumbo piston core (EW0408–85JC; 59° 33.3′N, 144° 9.21′W,
682 m water depth) recovered from the northern Gulf of Alaska continental slope reveal
changes in productivity and nutrient utilization over the last 17,000 years. Maximum...
We examine the relation between δ¹⁸O in rainwater collected in southwestern Oregon
and climate variables including temperature, parcel trajectory, precipitation amount, and
specific humidity. Local surface air temperature at the time of sample collection explains a
large proportion of δ¹⁸O variability, suggesting that paleoclimatic archives that are related
to rainfall...
We present a new nitrogen isotope model incorporated into the three-dimensional ocean component of a global Earth system climate model designed for millennial timescale simulations. The model includes prognostic tracers for the two stable nitrogen isotopes, 14N and 15N, in the nitrate (NO3−), phytoplankton, zooplankton, and detritus variables of the...
The Penman‐Monteith equation is often used to estimate transpiration, but an important limitation to this approach, especially for mountainous forested sites, is an accurate estimate of canopy conductance averaged over the area of interest (Gs). We propose a method for estimating watershed‐scale transpiration using estimates of Gs derived from measurements...
The primary Mg/Ca ratio of foraminiferal shells is a potentially valuable paleoproxy for sea surface
temperature (SST) reconstructions. However, the reliable extraction of this ratio from sedimentary calcite
assumes that we can overcome artifacts related to foraminiferal ecology and partial dissolution, as well as
contamination by secondary calcite and clay....
Mg/Ca ratios in planktonic foraminifera reflect calcification temperatures and are thus useful for sea
surface temperature (SST) reconstructions. Despite the obvious utility of this paleoceanographic tracer,
problems of dissolution, gametogenic calcification, and contaminant phases have thus far limited
confidence in Mg/Ca-based reconstructions. Here we show strong evidence of Mg heterogeneity...
Plankton tows from the northern California Current constrain biological and physical
influences on living planktonic foraminifera. In this region, the dominant factors controlling the
size and distribution of symbiotic and asymbiotic species are light and food. Food decreases offshore.
Light, needed for symbiont photosynthesis, increases offshore as water turbidity lessens....