/pdf/climate-models-and-their-evaluation-3l7t3uekup.pdf

Climate models and their evaluation

Characterizing flow and transport in fractured geological media: A review

A new version of the general circulation model CNRM-CM has been developed jointly by CNRM-GAME (Centre National de Recherches Meteorologiques—Groupe d’etudes de l’Atmosphere Meteorologique) and Cerfacs (Centre Europeen de Recherche et de Formation Avancee) in order to contribute to phase 5 of the Coupled Model Intercomparison Project (CMIP5). The purpose of the study is to describe its main features and to provide a preliminary assessment of its mean climatology. CNRM-CM5.1 includes the atmospheric model ARPEGE-Climat (v5.2), the ocean model NEMO (v3.2), the land surface scheme ISBA and the sea ice model GELATO (v5) coupled through the OASIS (v3) system. The main improvements since CMIP3 are the following. Horizontal resolution has been increased both in the atmosphere (from 2.8° to 1.4°) and in the ocean (from 2° to 1°). The dynamical core of the atmospheric component has been revised. A new radiation scheme has been introduced and the treatments of tropospheric and stratospheric aerosols have been improved. Particular care has been devoted to ensure mass/water conservation in the atmospheric component. The land surface scheme ISBA has been externalised from the atmospheric model through the SURFEX platform and includes new developments such as a parameterization of sub-grid hydrology, a new freezing scheme and a new bulk parameterisation for ocean surface fluxes. The ocean model is based on the state-of-the-art version of NEMO, which has greatly progressed since the OPA8.0 version used in the CMIP3 version of CNRM-CM. Finally, the coupling between the different components through OASIS has also received a particular attention to avoid energy loss and spurious drifts. These developments generally lead to a more realistic representation of the mean recent climate and to a reduction of drifts in a preindustrial integration. The large-scale dynamics is generally improved both in the atmosphere and in the ocean, and the bias in mean surface temperature is clearly reduced. However, some flaws remain such as significant precipitation and radiative biases in many regions, or a pronounced drift in three dimensional salinity.

/pdf/the-cnrm-cm5-1-global-climate-model-description-and-basic-vx5kg93mbd.pdf

The CNRM-CM5.1 global climate model: description and basic evaluation

Foreword 1. Introduction 2. Runoff, erosion and delivery to the coastal ocean 3. Temporal variations 4. Human impacts Appendices. Global River Database: Appendix A: North and Central America Appendix B: South America Appendix C: Europe Appendix D: Africa Appendix E: Eurasia Appendix F: Asia Appendix G: Oceania References Index.

/pdf/river-discharge-to-the-coastal-ocean-a-global-synthesis-571z1g19ts.pdf

River Discharge to the Coastal Ocean: A Global Synthesis

A review of techniques, advances and outstanding issues in numerical modelling for rock mechanics and rock engineering

Simulation des débits: l'Orne, la Dives, la Seulles.

A new technique for the quick upscaling of absolute permeabilities is presented. It is shown that this method and the tensorial renormalization are more reliable than the standard renormalization, the Kruel-Romeu formula and the algebraic means, for the two high anisotropy ratios, for the two different block sizes and for the two geostatistical models we have tested. The comparison of the execution time for the different techniques leads us to recommend the use of the new method in the case where the non-diagonal terms of the permeability tensors are not necessary. If the non-diagonal terms are necessary we recommend the use of the tensorial renormalization.

Simplified Renormalization: A New Quick Upscaling Technique

Hydraulic fractures may not develop perpendicularly to the least principal stress direction when the rock is anisotropic with respect to its strength. This has been taken to advantage to develop two heat exchangers in a shallow granite. First a hydraulic fracture was developed at 186 m in a first borehole; its orientation was defined by inspecting the borehole with a T.V.camera and using shut-in pressure measurement as well as a preliminary stress determination to show that the fracture had not turned away from the wellbore. A second well, bored 30 m away from the first one, intersected the fracture at the 156 m depth. The second heat exchanger was prepared by developing, from a third borehole, a second hydraulic fracture which intersected the first one somewhere between the two first boreholes.

Shallow Depth Experimentation on the Concept of Energy Extraction from Deep Hot Dry Rocks

In this study, an original methodology is proposed to couple surface and subsurface flow. This methodology is based on an upscaling approach, which allows for benefiting from high resolution hydraulic modeling outputs to improve th e representation of fluctuating river stage in a regional scale hydrogeological model. We first describe the general modeling strategy and our case study in the Oise River basin. The res ults then illustrate the efficiency of this strategy to simulate realistic river stages at the regional scale, and the impact of the resulting river stage fluctuations on the piezometric head.

https://congress.cimne.com/cmwr2010/Proceedings/docs/p60.pdf

Contribution of 1D river flow modeling to the quantification of stream-aquifer interactions in a regional hydrological model

The phreatic aquifer of the central Altiplano shows a C1 concentration that increases from 0.5 meq 1" upstream to 150 meq 1" downstream. The main outflow process from the aquifer is the upward flow E into the unsaturated zone associated to evaporation close to soil surface. A relation has been established for any arid zone areas on the base of isotopic profiles: E (mm Yi') = 63 Z-'.' where Z (m) is the water table depth under soil surface. The aquifer under study may have acquired its high chlorine content during last lacustrine phase (Tauca, 12 ka BP). Arguments for this hypothesis are: (i) maximum level of the lake (3780 m) higher than present soil elevation in the area, (i9 same order of salinity in the paleolake and in the more saline groundwater, (iii) weak molar ratio of Li/Cl in saline groundwater and in the Tauca, (iv) modelling of C1 transport over 11 O00 years consistent with observed spatial evolution of C1 in groundwater. To this scenario, might be superimposed the assumption of a delay for the convective transfer of salt towards south by the coupled effects of accumulation of salt in the unsaturated zone by evaporation from the aquifer during thousand or so years, and of the subsequent return of this salt downwards to the aquifer during some short rainy periods. The Sr/%, major and trace element compositions of surface and groundwater support this proposed scenario. 87 * Work performed within the fiamework of the "Programme National de Recherche en Hydrologie" and the I scientific co-operation betdeen France and Bolivia between the ORSTOM and the UMSA. --. .. . . . . . . 1

/pdf/isotopic-and-chemical-composition-of-groundwater-in-the-2b9zmh1ey7.pdf

Emmanuel Ledoux

Papers

Simulation des débits: l'Orne, la Dives, la Seulles.

Simplified Renormalization: A New Quick Upscaling Technique

Shallow Depth Experimentation on the Concept of Energy Extraction from Deep Hot Dry Rocks

Contribution of 1D river flow modeling to the quantification of stream-aquifer interactions in a regional hydrological model

Isotopic and chemical composition of groundwater in the Bolivian altiplano, present space evolution records hydrologic conditions since 11000 Yr