Search results for "project"

Discovery potential of xenon-based neutrinoless double beta decay experiments in light of small angular scale CMB observations

2013

The South Pole Telescope (SPT) has probed an expanded angular range of the CMB temperature power spectrum. Their recent analysis of the latest cosmological data prefers nonzero neutrino masses, with Sigma m(nu) = (0.32 +/- 0.11) eV. This result, if con firmed by the upcoming Planck data, has deep implications on the discovery of the nature of neutrinos. In particular, the values of the effective neutrino mass m(beta beta) involved in neutrinoless double beta decay (beta beta 0 nu) are severely constrained for both the direct and inverse hierarchy, making a discovery much more likely. In this paper, we focus in xenon-based beta beta 0 nu experiments, on the double grounds of their good perfo…

The stereographic coordinate system

2003

Bias correction of dynamically downscaled precipitation to compute soil water deficit for explaining year-to-year variation of tree growth over north…

2017

This paper documents the accuracy of a post-correction method applied to precipitation regionalized by the Weather Research and Forecasting (WRF) Regional Climate Model (RCM) for improving simulated rainfall and feeding impact studies. The WRF simulation covers Burgundy (northeastern France) at a 8-km resolution and over a 20-year long period (1989–2008). Previous results show a strong deficiency of the WRF model for simulating precipitation, especially when convective processes are involved. In order to reduce such biases, a Quantile Mapping (QM) method is applied to WRF-simulated precipitation using the mesoscale atmospheric analyses system SAFRAN («Système d'Analyse Fournissant des Rense…

An original way to evaluate daily rainfall variability simulated by a regional climate model: the case of South African austral summer rainfall

2014

We discuss the value of a clustering approach as a tool for evaluating daily rainfall output from climate models. Ascendant hierarchical clustering is used to evaluate how well South African recurrent daily rainfall patterns are simulated during the austral summer (December to February 1970–1971 to 1998–1999). A set of 35-km regional climate simulations, run with the WRF model and driven by the ERA40 reanalysis, is chosen as a case study. Six recurrent patterns are identified and compared to the observed clusters obtained by applying the same methodology to 5352 daily rain gauge records. Two of the WRF clusters describe either a persistent and widespread dryness (65% of the days) or pattern…

The Southern Annular Mode seen through weather regimes

2012

This article investigates the prominent features of the Southern Hemisphere (south of 20°S) atmospheric circulation when extracted using EOF analysis and a k-means clustering algorithm. The focus is on the southern annular mode (SAM), the nature of its recent trend, and the zonal symmetry of associated spatial patterns. The study uses the NCEP–Department of Energy Atmospheric Model Intercomparison Project II Reanalysis (NCEP-2) (period 1979–2009) to obtain robust patterns over the recent years and the Twentieth Century Reanalysis Project (period 1871–2008) to document decadal changes. Also presented is a comparison of these signals against a station-based reconstruction of the SAM index an…

Mixed-Phase Clouds: Progress and Challenges

2017

Mixed-phase clouds represent a three-phase colloidal system consisting of water vapor, ice particles, and coexisting supercooled liquid droplets. Mixed-phase clouds are ubiquitous in the troposphere, occurring at all latitudes from the polar regions to the tropics. Because of their widespread nature, mixed-phase processes play critical roles in the life cycle of clouds, precipitation formation, cloud electrification, and the radiative energy balance on both regional and global scales. Yet, in spite of many decades of observations and theoretical studies, our knowledge and understanding of mixed-phase cloud processes remains incomplete. Mixed-phase clouds are notoriously difficult to represe…

Temperature-related mortality impacts under and beyond Paris Agreement climate change scenarios.

2018

The Paris Agreement binds all nations to undertake ambitious efforts to combat climate change, with the commitment to hold warming well below 2 degrees C in global mean temperature (GMT), relative to pre-industrial levels, and to pursue efforts to limit warming to 1.5 degrees C. The 1.5 degrees C limit constitutes an ambitious goal for which greater evidence on its benefits for health would help guide policy and potentially increase the motivation for action. Here we contribute to this gap with an assessment on the potential health benefits, in terms of reductions in temperature-related mortality, derived from the compliance to the agreed temperature targets, compared to more extreme warmin…

Mid-century effects of Climate Change on African monsoon dynamics using the A1B emission scenario

2012

Future climate changes in African regions are model-dependent and there is no consensus regarding Sahelian rainfall by the end of this century. Using 12 atmosphere-ocean global climate models of the third Coupled Model Intercomparison Project (CMIP3) we propose a multi-model (MM) analysis contrasting the 1960–1999 period (20c3m integration) and the 2031–2070 period (A1B emission scenario). The analyses are based on MM response but also on the ‘one model-one vote’ concept to give the same weight to each model. The results show robust signals in the rainfall response, i.e., increasing (decreasing) amounts in central (western) Sahel associated with specific changes in atmospheric dynamics. The…

IWAL–An Interactive Weather Analysis Laboratory

2015

Abstract Complementary key elements of meteorological education are the provision of a thorough theoretical understanding of the physical laws governing atmospheric motions, and the hands-on investigation and visualization of specific weather systems. However, the latter task is technically challenging, because specific skills must be acquired for flexibly handling meteorological data. Some examples are superimposing satellite pictures and reanalysis fields, producing an isentropic potential vorticity (PV) map, and visualizing a vertical section across a flow feature of interest. Although learning these technical issues has its own merits, it can distract students from investigating the com…

A new hybrid procedure for the definition of seismic vulnerability in Mediterranean cross-border urban areas

2016

Assessment of seismic vulnerability of urban areas provides fundamental information for activities of planning and management of emergencies. The main difficulty encountered when extending vulnerability evaluations to urban contexts is the definition of a framework of assessment appropriate for the specific characteristics of the site and providing reliable results with a reasonable duration of surveys and post-processing of data. The paper proposes a new procedure merging different typologies of information recognized on the territories investigated and for this reason called “hybrid.” Knowledge of historical events influencing urban evolution and analysis of recurrent building technologie…