Silvio Gualdi | CMCC - Academia.edu (original) (raw)
Papers by Silvio Gualdi
Seasonal forecasts are essential to offer early-warning decision support systems that can help to... more Seasonal forecasts are essential to offer early-warning decision support systems that can help to reduce the socio-economics related risk associated to some anomalous events. Advances in statistical prediction are often associated with the enhance of understanding that usually leads to improve dynamical prediction. Thereby, both approaches are frequently combined in order to increase the robustness of the forecast.
Journal of Climate, 2021
The influence of the Atlantic multidecadal variability (AMV) on the North Atlantic storm track an... more The influence of the Atlantic multidecadal variability (AMV) on the North Atlantic storm track and eddy-driven jet in the winter season is assessed via a coordinated analysis of idealized simulations with state-of-the-art coupled models. Data used are obtained from a multimodel ensemble of AMV± experiments conducted in the framework of the Decadal Climate Prediction Project component C. These experiments are performed by nudging the surface of the Atlantic Ocean to states defined by the superimposition of observed AMV± anomalies onto the model climatology. A robust extratropical response is found in the form of a wave train extending from the Pacific to the Nordic seas. In the warm phase of the AMV compared to the cold phase, the Atlantic storm track is typically contracted and less extended poleward and the low-level jet is shifted toward the equator in the eastern Atlantic. Despite some robust features, the picture of an uncertain and model-dependent response of the Atlantic jet e...
The Mediterranean region under climate change, 2016
Introduction The Mediterranean region has quite a unique character that results both from physiog... more Introduction The Mediterranean region has quite a unique character that results both from physiographic conditions and historical and societal developments. Because of the latitude range it covers, the Mediterranean region is a transition area under the influence of both the temperate mid-latitude climate and the hotter-drier North-African climate. In addition, the region features a nearly enclosed sea surrounded by highly urbanized littorals and mountains in which numerous rivers have their ..
In a world with increased international focus on energy use, benchmarking consumption across coun... more In a world with increased international focus on energy use, benchmarking consumption across countries can inform decision makers about their country’s relative performance and opportunities for improvement. During the past decades, the energy field has been on the frontline of this exercise with energy consumption-and by association energy intensity and productivitybecoming a considerable dimension for policy-related international cross-country comparison. However, benchmarking is more meaningful when comparisons are normalized for uncontrollable factors. One of these factors is climate variation that occurs across countries. The aim of this reseach is to provide methodologies to quantify the effect of climate conditions on energy consumption in the residential and commercial sectors as space heating and cooling incrinsgly represent the largest share of building energy consumption in most countries. We developed a time series of population weighted national climate indices which we...
Water, 2019
Climate scenarios produce climate change-related information and data at a geographical scale gen... more Climate scenarios produce climate change-related information and data at a geographical scale generally not useful for coastal planners to study impacts locally. To provide a suitable characterization of climate-related hazards in the North Adriatic Sea coast, a model chain, with progressively higher resolution was developed and implemented. It includes Global and Regional Circulation Models representing atmospheric and oceanic dynamics for the global and sub-continental domains, and hydrodynamic/wave models useful to analyze physical impacts of sea-level rise and coastal erosion at a sub-national/local scale. The model chain, integrating multiple types of numerical models running at different spatial scales, provides information about spatial and temporal patterns of relevant hazard metrics (e.g., sea temperature, atmospheric pressure, wave height), usable to represent climate-induced events causing potential environmental or socio-economic damages. Furthermore, it allows the discu...
Bulletin of the American Meteorological Society, 2016
The Mediterranean is expected to be one of the most prominent and vulnerable climate change “hots... more The Mediterranean is expected to be one of the most prominent and vulnerable climate change “hotspots” of the twenty-first century, and the physical mechanisms underlying this finding are still not clear. Furthermore, complex interactions and feedbacks involving ocean–atmosphere–land–biogeochemical processes play a prominent role in modulating the climate and environment of the Mediterranean region on a range of spatial and temporal scales. Therefore, it is critical to provide robust climate change information for use in vulnerability–impact–adaptation assessment studies considering the Mediterranean as a fully coupled environmental system. The Mediterranean Coordinated Regional Downscaling Experiment (Med-CORDEX) initiative aims at coordinating the Mediterranean climate modeling community toward the development of fully coupled regional climate simulations, improving all relevant components of the system from atmosphere and ocean dynamics to land surface, hydrology, and biogeochemi...
ABSTRACT Rising concentration of carbon dioxide (CO2) is expected to affect tropical cyclone (TC)... more ABSTRACT Rising concentration of carbon dioxide (CO2) is expected to affect tropical cyclone (TC) intensity, frequency, and genesis locations through an increase in global mean sea surface temperature (SST). This has been an area of intensive research for the past few decades with increasing use of high-resolution global climate models (GCMs) and various downscaling approaches [see Knutson et al. (2010) for a recent review]. The assumption appears to be that the dominant effect of increasing CO2 on TCs is through an increase in tropical mean SST. However, recent modeling studies suggest that both spatial patterns of SST warming and higher atmospheric CO2 concentrations can significantly affect global and regional TC statistics independent of the global mean SST warming (Vecchi et al. 2008; Zhao et al. 2009; Held and Zhao 2011). In this article we focus on an examination of the direct or fast effect of CO2 on global TC frequency from the multiple models participating in the U.S. CLIVAR Hurricane Working Group (HWG). An understanding of the direct effect of CO2 is important for both near- term TC projections and assessing the impact of geo- engineering schemes on future TC statistics, especially if as a consequence the atmospheric CO2 concentration increases with significantly delayed or alleviated SST warming.
Theoretical and Applied Climatology, 2006
The aim of this study is to describe the behaviour of tropical dynamics in the ECHAM4 model when ... more The aim of this study is to describe the behaviour of tropical dynamics in the ECHAM4 model when increased vertical resolution around the tropopause and in the planetary boundary layer is used. In this work we perform experiments with the ECHAM4 model using T30 horizontal resolution and 19 and 42 vertical levels. The impact of the increased vertical resolution on the simulation of tropical clouds and precipitation has been investigated. Therefore, the dynamic fields related to tropical convection have been analyzed. The results suggest a beneficial effect of the increased number of vertical levels on the convective scheme performance and on the related dynamic fields over the Tropics. The improvement of the rainfall climatologies in the 42-level model has been explained via the impact of vertical resolution on the cloud structure. In the cloud spectrum of the L42 simulation, a third peak appears around 600 hPa, revealing that when using higher vertical resolution the convective parametrization starts to represent cumulus congestus clouds.
Journal of Climate, 2014
In this work the authors investigate possible changes in the intensity of rainfall events associa... more In this work the authors investigate possible changes in the intensity of rainfall events associated with tropical cyclones (TCs) under idealized forcing scenarios, including a uniformly warmer climate, with a special focus on landfalling storms. A new set of experiments designed within the U.S. Climate Variability and Predictability (CLIVAR) Hurricane Working Group allows disentangling the relative role of changes in atmospheric carbon dioxide from that played by sea surface temperature (SST) in changing the amount of precipitation associated with TCs in a warmer world. Compared to the present-day simulation, an increase in TC precipitation was found under the scenarios involving SST increases. On the other hand, in a CO2-doubling-only scenario, the changes in TC rainfall are small and it was found that, on average, TC rainfall tends to decrease compared to the present-day climate. The results of this study highlight the contribution of landfalling TCs to the projected increase in ...
Journal of Climate, 2010
The double–intertropical convergence zone (DI) systematic error, affecting state-of-the-art coupl... more The double–intertropical convergence zone (DI) systematic error, affecting state-of-the-art coupled general circulation models (CGCMs), is examined in the multimodel Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) ensemble of simulations of the twentieth-century climate. The aim of this study is to quantify the DI error on precipitation in the tropical Pacific, with a specific focus on the relationship between the DI error and the representation of large-scale vertical circulation regimes in climate models. The DI rainfall signal is analyzed using a regime-sorting approach for the vertical circulation regimes. Through the use of this compositing technique, precipitation events are regime sorted based on the large-scale vertical motions, as represented by the midtropospheric Lagrangian pressure tendency ω500 dynamical proxy. This methodology allows partition of the precipitation signal into deep and shallow convective components. Following the regime-s...
Dynamics of Atmospheres and Oceans, 2010
Deep Sea Research Part II: Topical Studies in Oceanography, 2003
Seasonal forecasts are essential to offer early-warning decision support systems that can help to... more Seasonal forecasts are essential to offer early-warning decision support systems that can help to reduce the socio-economics related risk associated to some anomalous events. Advances in statistical prediction are often associated with the enhance of understanding that usually leads to improve dynamical prediction. Thereby, both approaches are frequently combined in order to increase the robustness of the forecast.
Journal of Climate, 2021
The influence of the Atlantic multidecadal variability (AMV) on the North Atlantic storm track an... more The influence of the Atlantic multidecadal variability (AMV) on the North Atlantic storm track and eddy-driven jet in the winter season is assessed via a coordinated analysis of idealized simulations with state-of-the-art coupled models. Data used are obtained from a multimodel ensemble of AMV± experiments conducted in the framework of the Decadal Climate Prediction Project component C. These experiments are performed by nudging the surface of the Atlantic Ocean to states defined by the superimposition of observed AMV± anomalies onto the model climatology. A robust extratropical response is found in the form of a wave train extending from the Pacific to the Nordic seas. In the warm phase of the AMV compared to the cold phase, the Atlantic storm track is typically contracted and less extended poleward and the low-level jet is shifted toward the equator in the eastern Atlantic. Despite some robust features, the picture of an uncertain and model-dependent response of the Atlantic jet e...
The Mediterranean region under climate change, 2016
Introduction The Mediterranean region has quite a unique character that results both from physiog... more Introduction The Mediterranean region has quite a unique character that results both from physiographic conditions and historical and societal developments. Because of the latitude range it covers, the Mediterranean region is a transition area under the influence of both the temperate mid-latitude climate and the hotter-drier North-African climate. In addition, the region features a nearly enclosed sea surrounded by highly urbanized littorals and mountains in which numerous rivers have their ..
In a world with increased international focus on energy use, benchmarking consumption across coun... more In a world with increased international focus on energy use, benchmarking consumption across countries can inform decision makers about their country’s relative performance and opportunities for improvement. During the past decades, the energy field has been on the frontline of this exercise with energy consumption-and by association energy intensity and productivitybecoming a considerable dimension for policy-related international cross-country comparison. However, benchmarking is more meaningful when comparisons are normalized for uncontrollable factors. One of these factors is climate variation that occurs across countries. The aim of this reseach is to provide methodologies to quantify the effect of climate conditions on energy consumption in the residential and commercial sectors as space heating and cooling incrinsgly represent the largest share of building energy consumption in most countries. We developed a time series of population weighted national climate indices which we...
Water, 2019
Climate scenarios produce climate change-related information and data at a geographical scale gen... more Climate scenarios produce climate change-related information and data at a geographical scale generally not useful for coastal planners to study impacts locally. To provide a suitable characterization of climate-related hazards in the North Adriatic Sea coast, a model chain, with progressively higher resolution was developed and implemented. It includes Global and Regional Circulation Models representing atmospheric and oceanic dynamics for the global and sub-continental domains, and hydrodynamic/wave models useful to analyze physical impacts of sea-level rise and coastal erosion at a sub-national/local scale. The model chain, integrating multiple types of numerical models running at different spatial scales, provides information about spatial and temporal patterns of relevant hazard metrics (e.g., sea temperature, atmospheric pressure, wave height), usable to represent climate-induced events causing potential environmental or socio-economic damages. Furthermore, it allows the discu...
Bulletin of the American Meteorological Society, 2016
The Mediterranean is expected to be one of the most prominent and vulnerable climate change “hots... more The Mediterranean is expected to be one of the most prominent and vulnerable climate change “hotspots” of the twenty-first century, and the physical mechanisms underlying this finding are still not clear. Furthermore, complex interactions and feedbacks involving ocean–atmosphere–land–biogeochemical processes play a prominent role in modulating the climate and environment of the Mediterranean region on a range of spatial and temporal scales. Therefore, it is critical to provide robust climate change information for use in vulnerability–impact–adaptation assessment studies considering the Mediterranean as a fully coupled environmental system. The Mediterranean Coordinated Regional Downscaling Experiment (Med-CORDEX) initiative aims at coordinating the Mediterranean climate modeling community toward the development of fully coupled regional climate simulations, improving all relevant components of the system from atmosphere and ocean dynamics to land surface, hydrology, and biogeochemi...
ABSTRACT Rising concentration of carbon dioxide (CO2) is expected to affect tropical cyclone (TC)... more ABSTRACT Rising concentration of carbon dioxide (CO2) is expected to affect tropical cyclone (TC) intensity, frequency, and genesis locations through an increase in global mean sea surface temperature (SST). This has been an area of intensive research for the past few decades with increasing use of high-resolution global climate models (GCMs) and various downscaling approaches [see Knutson et al. (2010) for a recent review]. The assumption appears to be that the dominant effect of increasing CO2 on TCs is through an increase in tropical mean SST. However, recent modeling studies suggest that both spatial patterns of SST warming and higher atmospheric CO2 concentrations can significantly affect global and regional TC statistics independent of the global mean SST warming (Vecchi et al. 2008; Zhao et al. 2009; Held and Zhao 2011). In this article we focus on an examination of the direct or fast effect of CO2 on global TC frequency from the multiple models participating in the U.S. CLIVAR Hurricane Working Group (HWG). An understanding of the direct effect of CO2 is important for both near- term TC projections and assessing the impact of geo- engineering schemes on future TC statistics, especially if as a consequence the atmospheric CO2 concentration increases with significantly delayed or alleviated SST warming.
Theoretical and Applied Climatology, 2006
The aim of this study is to describe the behaviour of tropical dynamics in the ECHAM4 model when ... more The aim of this study is to describe the behaviour of tropical dynamics in the ECHAM4 model when increased vertical resolution around the tropopause and in the planetary boundary layer is used. In this work we perform experiments with the ECHAM4 model using T30 horizontal resolution and 19 and 42 vertical levels. The impact of the increased vertical resolution on the simulation of tropical clouds and precipitation has been investigated. Therefore, the dynamic fields related to tropical convection have been analyzed. The results suggest a beneficial effect of the increased number of vertical levels on the convective scheme performance and on the related dynamic fields over the Tropics. The improvement of the rainfall climatologies in the 42-level model has been explained via the impact of vertical resolution on the cloud structure. In the cloud spectrum of the L42 simulation, a third peak appears around 600 hPa, revealing that when using higher vertical resolution the convective parametrization starts to represent cumulus congestus clouds.
Journal of Climate, 2014
In this work the authors investigate possible changes in the intensity of rainfall events associa... more In this work the authors investigate possible changes in the intensity of rainfall events associated with tropical cyclones (TCs) under idealized forcing scenarios, including a uniformly warmer climate, with a special focus on landfalling storms. A new set of experiments designed within the U.S. Climate Variability and Predictability (CLIVAR) Hurricane Working Group allows disentangling the relative role of changes in atmospheric carbon dioxide from that played by sea surface temperature (SST) in changing the amount of precipitation associated with TCs in a warmer world. Compared to the present-day simulation, an increase in TC precipitation was found under the scenarios involving SST increases. On the other hand, in a CO2-doubling-only scenario, the changes in TC rainfall are small and it was found that, on average, TC rainfall tends to decrease compared to the present-day climate. The results of this study highlight the contribution of landfalling TCs to the projected increase in ...
Journal of Climate, 2010
The double–intertropical convergence zone (DI) systematic error, affecting state-of-the-art coupl... more The double–intertropical convergence zone (DI) systematic error, affecting state-of-the-art coupled general circulation models (CGCMs), is examined in the multimodel Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) ensemble of simulations of the twentieth-century climate. The aim of this study is to quantify the DI error on precipitation in the tropical Pacific, with a specific focus on the relationship between the DI error and the representation of large-scale vertical circulation regimes in climate models. The DI rainfall signal is analyzed using a regime-sorting approach for the vertical circulation regimes. Through the use of this compositing technique, precipitation events are regime sorted based on the large-scale vertical motions, as represented by the midtropospheric Lagrangian pressure tendency ω500 dynamical proxy. This methodology allows partition of the precipitation signal into deep and shallow convective components. Following the regime-s...
Dynamics of Atmospheres and Oceans, 2010
Deep Sea Research Part II: Topical Studies in Oceanography, 2003
J. Climate, 27, 7493-7501; doi: http://dx.doi.org/10.1175/JCLI-D-14-00339.1, 2014
The Mediterranean has been identified as one of the most responsive regions to climate change. It... more The Mediterranean has been identified as one of the most responsive regions to climate change. It has been conjectured that one of the effects of a warmer climate could be to make the Mediterranean Sea prone to the formation of hurricanes. Already in the present climate regime, however, a few of the numerous low pressure systems that form in the area develop a dynamical evolution similar to the one of tropical cyclones. Even if their spatial extent is generally smaller and the life cycle shorter compared to tropical cyclones, such storms produce severe damage on the highly populated coastal areas surrounding the Mediterranean Sea. This study, based on the analysis of individual realistically simulated storms in homogeneous long-term and high-resolution data from multiple climate change scenarios, shows that the projected effect of climate change on Mediterranean tropical-like cyclones is decreased frequency and a tendency toward a moderate increase of intensity.
