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Mel R.,University of Padua | Sterl A.,Royal Netherlands Meteorological Institute | Lionello P.,University of Salento | Lionello P.,Euro Mediterranean Center on Climate Change
Natural Hazards and Earth System Science | Year: 2013

Climate change impact on storm surge regime is of great importance for the safety and maintenance of Venice. In this study a future storm surge scenario is evaluated using new high resolution sea level pressure and wind data recently produced by EC-Earth, an Earth System Model based on the operational seasonal forecast system of the European Centre for Medium-Range Weather Forecasts (ECMWF). The study considers an ensemble of six 5 yr long simulations of the rcp45 scenario at 0.25 resolution and compares the 2094-2098 to the 2004-2008 period. EC-Earth sea level pressure and surface wind fields are used as input for a shallow water hydrodynamic model (HYPSE) which computes sea level and barotropic currents in the Adriatic Sea. Results show that a high resolution climate model is needed for producing realistic values of storm surge statistics and confirm previous studies in that they show little sensitivity of storm surge levels to climate change. However, some climate change signals are detected, such as increased persistence of high pressure conditions, an increased frequency of windless hour, and a decreased number of moderate windstorms. © 2013 Author(s). Source

Alberini A.,University of Maryland University College | Alberini A.,Fondazione Eni Enrico Mattei | Alberini A.,ETH Zurich | Bigano A.,Fondazione Eni Enrico Mattei | Bigano A.,Euro Mediterranean Center on Climate Change
Energy Economics | Year: 2015

We evaluate incentives for residential energy upgrades in Italy using data from an original survey of Italian homeowners. In this paper, attention is restricted to heating system replacements, and to the effect of monetary and non-monetary incentives on the propensity to replace the heating equipment with a more efficient one. To get around adverse selection and free riding issues, we ask stated preference questions to those who weren't planning energy efficiency upgrades any time soon. We argue that these persons are not affected by these behaviors. We use their responses to fit an energy-efficiency renovations curve that predicts the share of the population that will undertake these improvements for any given incentive level. This curve is used to estimate the CO2 emissions saved and their cost-effectiveness. Respondents are more likely to agree to a replacement when the savings on the energy bills are larger and experienced over a longer horizon, and when rebates are offered to them. Reminding the respondents about possible CO2 emissions reductions (our non-monetary incentive) had little effect. Even under optimistic assumptions, monetary incentives similar to those in the Italian tax credit program are generally not cost-effective. © 2015 Elsevier B.V. Source

Fratini G.,Li-Cor Biosciences, Inc. | McDermitt D.K.,Li-Cor Biosciences, Inc. | Papale D.,University of Tuscia | Papale D.,Euro Mediterranean Center on Climate Change
Biogeosciences | Year: 2014

Errors in gas concentration measurements by infrared gas analysers can occur during eddy-covariance campaigns, associated with actual or apparent instrumental drifts or biases due to thermal expansion, dirt contamination, aging of components or errors in field operations. If occurring on long timescales (hours to days), these errors are normally ignored during flux computation, under the assumption that errors in mean gas concentrations do not affect the estimation of turbulent fluctuations and, hence, of covariances. By analysing instrument theory of operation, and using numerical simulations and field data, we show that this is not the case for instruments with curvilinear calibrations; we further show that if not appropriately accounted for, concentration biases can lead to roughly proportional systematic flux errors, where the fractional errors in fluxes are about 30-40% the fractional errors in concentrations. We quantify these errors and characterize their dependency on main determinants. We then propose a correction procedure that largely-potentially completely-eliminates these errors. The correction, to be applied during flux computation, is based on knowledge of instrument calibration curves and on field or laboratory calibration data. Finally, we demonstrate the occurrence of such errors and validate the correction procedure by means of a field experiment, and accordingly provide recommendations for in situ operations. © 2014 Author(s). Source

Turco M.,Euro Mediterranean Center on Climate Change | Sanna A.,Euro Mediterranean Center on Climate Change | Herrera S.,University of Cantabria | Llasat M.-C.,University of Barcelona | Gutierrez J.M.,Institute Fisica Of Cantabria Ifca
Climatic Change | Year: 2013

In this paper we analyze some caveats found in the state-of-the-art ENSEMBLES regional projections dataset focusing on precipitation over Spain, and highlight the need of a task-oriented validation of the GCM-driven control runs. In particular, we compare the performance of the GCM-driven control runs (20C3M scenario) with the ERA40-driven ones ("perfect" boundary conditions) in a common period (1961-2000). Large deviations between the results indicate a large uncertainty/bias for the particular RCM-GCM combinations and, hence, a small confidence for the corresponding transient simulations due to the potential nonlinear amplification of biases. Specifically, we found large biases for some RCM-GCM combinations attributable to RCM in-house problems with the particular GCM coupling. These biases are shown to distort the corresponding climate change signal, or "delta", in the last decades of the 21st century, considering the A1B scenario. Moreover, we analyze how to best combine the available RCMs to obtain more reliable projections. © 2013 Springer Science+Business Media Dordrecht. Source

D'Agostino R.,University of Salento | D'Agostino R.,Euro Mediterranean Center on Climate Change | Lionello P.,University of Salento | Lionello P.,Euro Mediterranean Center on Climate Change
Climate Dynamics | Year: 2016

This study analyzes the evolution of the Hadley Circulation (HC) during the twentieth century in ERA-20CM (AMIP-experiment) and ERA-20C (reanalysis). These two recent ECMWF products provide the opportunity for a new analysis of the HC trends and of their uncertainties. Further, the effect of sea surface temperature forcing (including its uncertainty) and data assimilation are investigated. Also the ECMWF reanalysis ERA-Interim, for the period 1979–2010, is considered for a complementary analysis. Datasets present important differences in characteristics and trends of the HC. In ERA-20C HC is weaker (especially the Southern Hemisphere HC) and the whole Northern Hemisphere HC is located more southward than in ERA-20CM (especially in the boreal summer). In ERA-Interim HC is stronger and wider than both other simulations. In general, the magnitude of trends is larger and more statistically significant in ERA-20C than in ERA-20CM. The presence of large multidecadal variability across twentieth century raises doubts on the interpretation of recent behavior, such as the onset of sustained long term trends, particularly for the HC strength. In spite of this, the southward shift of the Southern Edge and widening of the Southern Hemisphere HC appear robust features in all datasets, and their trends have accelerated in the last three decades, but actual expansion rates remain affected by considerable uncertainty. Inconsistencies between datasets are attributed to the different reproduction of the links between the HC width and factors affecting it (such as mean global temperature, tropopause height, meridional temperature contrast and planetary waves), which appear more robust in ERA-20CM than in ERA-20C, particularly for the two latter factors. Further, in ERA-Interim these correlations are not statistically significant. These outcomes suggest that data assimilation degrades the links between the HC and features influencing its dynamics. © 2016 Springer-Verlag Berlin Heidelberg Source

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