Institut Universitaire de France

About: Institut Universitaire de France is a education organization based out in Paris, France. It is known for research contribution in the topics: Population & Catalysis. The organization has 1905 authors who have published 9042 publications receiving 309878 citations.

Interhemispheric synchrony of the last deglaciation inferred from alkenone palaeothermometry

Abstract: The relative timings of the last deglacial warming in the Southern and Northern hemispheres are not well constrained, but are a crucial component in understanding the mechanisms of deglaciation1. A clearer picture of the degree of interhemispheric synchrony has been obscured by a dearth of high-resolution temperature records that can be tied to the absolute calendar timescale. Moreover, the quantification of tropical temperatures during the last glacial cycle is controversial2–8. Here we apply the alkenone method of sea surface temperature reconstruction9,10 to several high-resolution sediment cores recovered from the tropical Indian Ocean between 20° N and 20° S. The inferred initial sea surface temperature warming ∼15,000 calendar years ago at 20° S is in phase with Northern Hemisphere sea (this study) and air11 temperature changes, but lags Antarctic warming12–14 by several millennia. This finding, along with the results of recent modelling studies15,16, provides strong support for the idea that changes in the ocean's global thermohaline circulation were not the only cause of interhemispheric climate teleconnection during the last deglaciation.

Retreat of Pine Island Glacier controlled by marine ice-sheet instability

Abstract: At present the Pine Island Glacier in West Antarctica is thinning and its grounding line has retreated. This work uses three ice-flow models to investigate the stability of the glacier and finds that the grounding line could retreat a further 40 km, which is equivalent to a rise in sea level of 3.5–10 mm over a 20 year period.

TD-DFT Assessment of Functionals for Optical 0–0 Transitions in Solvated Dyes

Abstract: Using TD-DFT, we performed simulations of the adiabatic energies of 40 fluorescent molecules for which the experimental 0–0 energies in condensed phase are available. We used six hybrid functionals (B3LYP, PBE0, M06, M06-2X, CAM-B3LYP, and LC-PBE) that have been shown to provide accurate transition energies in previous TD-DFT assessments, selected two diffuse-containing basis sets, and applied the most recent models for estimating bulk solvation effects. In each case, the correction arising from the difference of zero-point vibrational energies between the ground and the excited states has been consistently determined. Basis set effects have also been carefully studied. It turned out that PBE0 and M06 are the most effective functionals in terms of average deviation (mean absolute error of 0.22–0.23 eV). However, both the M06-2X global hybrid that contains more exact exchange and the CAM-B3LYP range-separated hybrid significantly improve the consistency of the prediction for a relatively negligible degrada...