Charge-Transfer Matrix Elements by FMO-LCMO Approach: Hole Transfer in DNA with Parameter Tuned Range-Separated DFT

A scheme for computing charge-transfer matrix elements with the linear combination of fragment molecular orbitals and the 'nonempirically tuned range-separated' density functional is presented. It takes account of the self-consistent orbital relaxation induced by environmental Coulomb field and the exchange interaction in fragment pairs at low computational scaling along the system size. The accuracy was confirmed numerically on benchmark systems of imidazole and furane homo-dimer cations. Applications to hole transfers in DNA nucleobase pairs and in a $\pi$-stack adenine octomer highlight the effects of orbital relaxation.Comment: 10 pages, 8 figure

Wetter subtropics and Hadley/Walker circulation in mid-Pliocene simulated by an atmospheric general circulation model

PMIP 3(Paleoclimate Modelling Intercomparison Project phase 3) Kyoto Workshop （Monday December 6th to Friday December 10th 2010）conference outpu

An initial intercomparison of atmospheric and oceanic climatology for the ICE-5G and ICE-4G models of LGM paleotopography

This paper investigates the impact of the new ICE-5G paleotopography dataset for Last Glacial Maximum (LGM) conditions on a coupled model simulation of the thermal and dynamical state of the glacial atmosphere and on both land surface and sea surface conditions. The study is based upon coupled climate simulations performed with the ocean–atmosphere–sea ice model of intermediate-complexity Climate de Bilt-coupled large-scale ice–ocean (ECBilt-Clio) model. Four simulations focusing on the Last Glacial Maximum [21 000 calendar years before present (BP)] have been analyzed: a first simulation (LGM-4G) that employed the original ICE-4G ice sheet topography and albedo, and a second simulation (LGM-5G) that employed the newly constructed ice sheet topography, denoted ICE-5G, and its respective albedo. Intercomparison of the results obtained in these experiments demonstrates that the LGM-5G simulation delivers significantly enhanced cooling over Canada compared to the LGM-4G simulation whereas positive temperature anomalies are simulated over southern North America and the northern Atlantic. Moreover, introduction of the ICE-5G topography is shown to lead to a deceleration of the subtropical westerlies and to the development of an intensified ridge over North America, which has a profound effect upon the hydrological cycle. Additionally, two flat ice sheet experiments were carried out to investigate the impact of the ice sheet albedo on global climate. By comparing these experiments with the full LGM simulations, it becomes evident that the climate anomalies between LGM-5G and LGM-4G are mainly driven by changes of the earth’s topography

A Unique Feature of the Asian Summer Monsoon Response to Global Warming: The Role of Different Land–Sea Thermal Contrast Change between the Lower and Upper Troposphere

Recent studies indicate that the view of a general weakening of the monsoon circulation in a warmer climate cannot be simply applied in the Asian monsoon regions. To understand the Asian summer monsoon response to global warming, idealized multi-model experiments are analyzed. In the coupled model response to increased CO2, monsoon westerlies in the lower troposphere are shifted poleward and slightly strengthened over land including South Asia and East Asia, while the tropical easterly jet in the upper troposphere are broadly weakened. The different circulation responses between the lower and upper troposphere is associated with vertically opposite changes in the meridional temperature gradient (MTG) between the Eurasian continent and the tropical Indian Ocean, with a strengthening (weakening) in the lower (upper) troposphere. Atmospheric model experiments to separate the effects of CO2 radiative forcing and sea surface temperature warming reveal that the strengthened MTG in the lower troposphere is explained by the CO2 forcing. On a global perspective, CO2-induced enhancement of the land–sea thermal contrast and resultant circulation changes are the most influential in the South Asian monsoon. This study emphasizes an important role of the land warming on the Asian monsoon response to global warming