Papers by Paolina Cerlini
The A.C.Q.U.A. (Advisable Conscious Quality Use from Assisi) project, promoted by the Climate and... more The A.C.Q.U.A. (Advisable Conscious Quality Use from Assisi) project, promoted by the Climate and Energy and Heritage Design courses of the Planet Life Design Master Program, addresses the theme of the recovery and regeneration of ancient wash-houses in the context of energy, environmental sustainability and innovation, a way of understanding cultural heritage in the wider sense of heritage community through the active participation of all the actors involved: universities, institutions, businesses, students and citizens. The proposal, tested in the municipalities of Assisi and Ruviano (ITALY), involves the creation of a "Community Wash House", a new way of carrying out the usual domestic act of washing clothes in the open air, next to the places where this rite was traditionally performed, in technologically innovative constructions that use renewable energy sources and encourage a reduction in household consumption of water and energy. This project is part of the training of professionals in the new inter-university course that combines knowledge of the tools of technical and scientific design with historical and cultural perspectives in a perspective of sustainable redevelopment of existing structures in the area and the use of alternative energy sources with low climate impact, calculated using the statistics of the Copernicus CDS.
Authorea (Authorea), Apr 30, 2023
Spontaneous aggregation of deep convection is a common feature of idealized numerical simulations... more Spontaneous aggregation of deep convection is a common feature of idealized numerical simulations of the tropical atmosphere in Radiative-Convective Equilibrium (RCE). However, at coarse grid resolution where deep convection is not fully resolved, the occurrence of this phenomenon is extremely sensitive to subgrid-scale processes. This study focuses on the role played by mixing and entrainment, either provided by the turbulence model or the implicit numerical dissipation. We have analyzed the results of two different models, WRF and SAM, and we have compared different configurations by varying the turbulence models, the numerical schemes and the horizontal spatial resolution. At coarse grid resolution (3 km), removing turbulent mixing prevents the occurrence of Convective Self-Aggregation (CSA) in low numerical diffusion models, while delaying it in high numerical diffusion models. When the horizontal grid resolution is refined to 1 km (thus reducing the implicit numerical dissipation), CSA is achieved only by increasing the explicit turbulent mixing. In this case, CSA was found to occur even with a small amount of shallow clouds. Therefore, this study suggests that the sensitivity of CSA to horizontal grid resolution is not primarily due to the corresponding decrease in shallow clouds. Instead, it is found that turbulent mixing and dissipation at small scales regulate the amplitude of humidity perturbations introduced by convection in the free troposphere: the greater the dissipation at small scales, the greater the size and the strength of humidity perturbations in the free troposphere that can destabilize the RCE state.
Journal of Advances in Modeling Earth Systems, Feb 1, 2023
The radiative‐convective equilibrium (RCE) of two models exhibiting convective aggregation has be... more The radiative‐convective equilibrium (RCE) of two models exhibiting convective aggregation has been compared. The goal of the work, following the suggestion from the RCE Model Intercomparison Project (RCEMIP), is to identify key parameters controlling self‐aggregation in RCE for both models, to discuss the processes controlled by these parameters and to underline the models similarities and differences. The two cloud resolving models studied, the SAM (System for Atmospheric Modeling) and the ARPS (Advanced Regional Prediction System), present similar statistics concerning precipitation, but different warming, and drying of the atmosphere, within the spread of the RCEMIP values. On the other hand, the two models show different strengths of the moisture feedback, due to the different saturation of the sub‐cloud layer. A saturated sub‐cloud layer in ARPS (which was not artificially imposed in the numerical setup) allows the localization of convection in moist regions, by weakening the negative influence of cold pools. Such a mechanism leads to a lower degree of aggregation (based on three organization metrics) and a weaker effect of the organized state on the average domain statistics in ARPS. Stronger cold pools in SAM, instead, help the creation of shallow clouds in dry regions, increasing the longwave feedback responsible for their expansion; while delocalizing convection in moist regions and therefore opposing high‐cloud radiative‐feedback. Further experiments are needed to generalize such findings to other RCEMIP models, also investigating the role of microphysics and turbulence schemes in regulating such mechanisms.
. Mediterranean Tropical-Like Cyclones, called “medicanes”, present a multiscale nature and their... more . Mediterranean Tropical-Like Cyclones, called “medicanes”, present a multiscale nature and their track and intensity have been recognized as highly sensitive to large-scale atmospheric forcing and to diabatic heating as represented by the physical parameterizations in numerical weather prediction. Here, we analyse the structure and investigate the predictability of medicanes with the aid of the European Centre for Medium-Range Weather Forecast (ECMWF) Integrated Forecast System (IFS) ensemble forecasting system with 25 perturbed members at 9 km horizontal resolution (compared to the 16 km operational resolution). The IFS ensemble system includes the representation of initial uncertainties from the ensemble data assimilation (EDA) and a recently developed uncertainty representation of the model physics with perturbed parameters (Stochastically Perturbed Parameterizations, SPP). The focus is on three medicanes, Ianos, Zorbas and Trixie that have been among the strongest in recent years. In particular, we have carried out separate ensemble simulations with initial perturbations, full physics SPP, and with a reduced set of SPP, where only convection is perturbed to highlight the convective nature of medicanes. It is found that compared to the operational analysis and satellite rainfall data, the forecasts reproduce the tropical-like features of these cyclones. Furthermore, the SPP simulations compare to the initial condition perturbation ensemble, in terms of tracking, intensity, precipitation and more generally in terms of ensemble skill and spread. Moreover, the study confirms that similar processes are at play in the development of the investigated three medicanes, in that the predictability of these cyclones is linked not only to the prediction of the precursor events (namely the deep cut-off low) but also to the interaction of the upper-level dynamically driven Potential Vorticity (PV) streamer with the tropospheric PV anomaly that is driven by surface heating and stratiform and convective condensational heating.
In this supporting information, we provide a deep explanation of all the perturbed parameters of ... more In this supporting information, we provide a deep explanation of all the perturbed parameters of the Stochastically Perturbed Parameterization (SPP) in Section S1 and a brief description of some of the statistical scores used in this study (Section S2).
Meteorological Applications, Mar 1, 2023
Water table elevation is a key feature for identifying the groundwater behaviour. Accordingly, ap... more Water table elevation is a key feature for identifying the groundwater behaviour. Accordingly, appropriate measurements—in terms of both frequency and spatial distribution—play a crucial role for capturing the aquifer response to recharge and withdrawals. However, numerical models simulating the main features of the behaviour of the water table elevation may help groundwater management, as an additional tool. In this article, soil moisture data from three well‐established global reanalyses (ERA5, CFS, and JRA‐55) are used for evaluating the flux in the vadose zone towards shallow unconfined aquifers, , in the Umbria region (central Italy). Then, according to the methodology proposed in Bongioannini Cerlini et al. (2021), where for the considered aquifers most of the recharge derives from the unsaturated zone, is used for simulating the water table evolution in time. With the aim of assessing which reanalysis is the most appropriate in simulating the evolution of groundwater levels, the properties of the correspondent land surface models (LSM) are examined, as they provide . For the considered aquifers, the analysis of the performance of the selected reanalyses confirms the validity of the proposed approach. Moreover, it points out the crucial role of the spreading of the water table elevation with respect to its mean value, as a significant parameter for selecting the most adequate reanalysis to use. In addition, the role in the LSM of the explored soil depth, hydraulic conductivity curve, and spatial resolution is highlighted. These results, in line with recent literature on the performance of the reanalyses, suggest to extend future work to other regions of the world.
The Radiative-Convective Equilibrium (RCE) of two models exhibiting convective aggregation has be... more The Radiative-Convective Equilibrium (RCE) of two models exhibiting convective aggregation has been compared. The goal of the work, following the suggestion from the Radiative-Convective Equilibrium Model Intercomparison Project (RCEMIP), is to identify key parameters controlling self-aggregation in RCE for both models and discuss the processes controlled by these parameters in order to find the simulations similarities and to test their differences. The two models studied, the SAM (System for Atmospheric Modeling) and the ARPS (Advanced Regional Prediction System), have different physical and numerical formulations. This allowed us to compare the sensitivity to processes related to self-aggregation. When self-aggregation occurs, the two models present similar statistics for what concerns precipitation, warming, and drying of the atmosphere and anvil cloud area reduction (leading to an "Iris effect'), within the spread of the RCEMIP values. On the other hand, they differ both in the degree of organization and the organization feedback: SAM is strongly organized (is on the highest quartile of the RCEMIP for the Iorg Index) and the convective organization is achieved by cloud-radiative feedback; ARPS is weakly organized (on the multi-model average of the RCEMIP for the Iorg Index) and the moisture-convection feedback is leading to the convective organization. The prevalence of one mechanism over the other has been found in the interaction between the microphysics and the sub-cloud layer properties. This comparison suggests that, in order to have a robust measure of climate sensitivity, climate models should include both types of convective organization mechanisms as shown by the two models.
International Journal of Climatology, 2022
Recent analyses of satellite and surface observations reported a negative annual rainfall trend i... more Recent analyses of satellite and surface observations reported a negative annual rainfall trend in central Italy. The complex orography of the Apennines and the strong influence of climate change in the Mediterranean basin complicates the explanation of such trends and their spatial variability. This work aims at describing the link between circulation weather types, orography and precipitation patterns observed in central Italy, as a first step towards the understanding of such climate trends. Using ERA5 reanalysis data from 1951 to 2019, four weather types are identified as most responsible for the spatial variability of rainfall in central Italy. They are associated with cyclonic circulations characterized by high water vapour transport coming from west, south‐west, south‐east and north‐east. The analysis of wind speed and precipitation climatology for the period 1951–2019, as derived from both surface observations and reanalysis, confirms a strong influence of moist south‐wester...
International Journal of Biometeorology, 2021
Even if the sensitivity of vegetation phenology to climate change has been accepted on global and... more Even if the sensitivity of vegetation phenology to climate change has been accepted on global and continental scales, the correlation between global warming and phenotypic variability shows a modulated answer depending on altitude, latitude, and the local seasonal thermal trend. To connect global patterns of change with local effects, we investigated the impact of the observed signal of warming found in Central Italy on two different willow species, Salix acutifolia and Salix smithiana, growing in three phenological gardens of the International Phenological Gardens’ network (IPG) located in different orographic positions. The time series of temperatures and phenological data for the period 2005–2018 were analysed first to find trends over time in the three gardens and then to correlate the recent local warming and the change in the two species phenology. The results confirmed the correlation between phenological trends and local trend of temperatures. In particular: budburst showed ...
Meteorological Applications
The current evolution of numerical weather prediction models, climate applications, warning and d... more The current evolution of numerical weather prediction models, climate applications, warning and decision support systems needs more information at increasingly finer scales. In this context, mesoscale meteorological networks (mesonets) can provide essential observations for the international community. However, they often suffer from the absence of a national and international coordination, scarce maintenance, inadequate data quality and redundancy. An integrated network design and the implementation of a unified quality management system could reveal the full socio‐economical benefits of mesonet information. This study provides a general procedure to realize an efficient and high‐quality mesonet starting from existing fragmented networks. The process starts by defining a network quality management system (NQMS), which is responsible for the station maintenance and the data quality control (QC) procedures. Stations are first classified based on their primary purpose, their landscape and the instruments siting and exposure in the station enclosure. Then, their quality performances are evaluated by a complex QC system made by numerous QC tests, whose specifications are tailored to the main surface observations. Finally, an integrated network design procedure is provided to identify observational lack and planning site interventions. The design is based on the purpose of the network and all the information gathered by the NQMS. Spatial, meteorological, climate and financial considerations are then used to decide whether to add, remove or modify observations. This procedure is tested in the Umbria region, Central Italy, where its implementation would lead to a considerable advancement in terms of regional weather and climate services.
Tellus A, 1999
Possible connections between spatial patterns, of limited regional extent and identified in telec... more Possible connections between spatial patterns, of limited regional extent and identified in teleconnection patterns and in blocking climatology studies, with hemispheric planetary-wave activity modes defined by the wave amplitude index (WAI) are investigated. The WAI probability density function (PDF) for the northern extratropics winter fields is estimated and the sensitivity of the WAI distribution to the presence of low-frequency variability modes is evaluated by stratifying the available dataset according to the sign of blocking and teleconnection indices. It is found that low-frequency variability modes affect both the mean and the variance of the wave amplitude index. Both the positive phase of the North Atlantic Oscillation (NAO) and the negative phase of the Pacific North American pattern (PNA) are associated with an enhanced frequency of very large amplitude planetary waves. Furthermore, distributions characterised by a maximum corresponding to high WAI values also exhibit a large variance. Negative NAO and positive PNA influence the mean and the variance of WAI PDF in the opposite sense. Similar results are found when the blocking index is considered. WAI PDFs relative to highly blocked months are broader with a secondary maximum corresponding to very high WAI values.
Atmosphere
Climate change has a strong impact on inland water bodies such as lakes. This means that the incr... more Climate change has a strong impact on inland water bodies such as lakes. This means that the increase in lake temperature recorded in recent decades-in Europe as well-can change the evaporation regime of the lakes. This, together with the variation of the water cycle, in particular precipitation, implies that the water mass balance of lakes may vary due to climate change. Water mass balance modeling is therefore of paramount importance to monitor lakes in the context of global warming. Although many studies have focused on such a modeling, there is no shared approach that can be used for any lake across the globe, irrespective of the size. This becomes even more problematic for shallow and small lakes, for which few studies exist. For this reason, in this paper the use of reanalysis data, in particular ERA5-Land provided by the European Centre for Medium-Range Weather Forecasts (ECMWF), is proposed for the mass balance modeling. In fact, ERA5-Land has a global coverage and it is the...
Procedia Engineering, 2017
Climate change influences hydrological cycle with a direct effect on groundwater resources, one o... more Climate change influences hydrological cycle with a direct effect on groundwater resources, one of the most important supply sources for human consumption and irrigation. In a scenario where General Circulation Models do not represent yet a usual tool for water industry managers, potentially the use of global atmospheric datasets is of great interest for evaluating groundwater resources. In this paper data from the European Centre for Medium-Range Weather Forecasts (ECMWF) are compared to local water table measurements. With particular regard to unconfined aquifers, the good correlation between the trend of soil moisture and local water table data is pointed out. Such a promising result authorizes further insights in order to refine reliable tools for evaluating available groundwater resources in a climate change scenario.
Hydrology and Earth System Sciences, 2005
In the EFFS Project, an attempt has been made to develop a general framework to study the predict... more In the EFFS Project, an attempt has been made to develop a general framework to study the predictability of severe convective rainfall events in the presence of orography. Convective activity is embedded in orographic rainfall and can be thought as the result of several physical mechanisms. Quantifying its variability on selected area and time scales requires choosing the best physical representation of the rainfall variability on these scales. The main goal was (i) to formulate a meaningful set of experiments to compute the oscillation of variance due to convection inside model forecasts in the presence of orography and (ii) to give a statistical measure of it that might be of value in the operational use of atmospheric data. The study has been limited to atmospheric scales that span the atmosphere from 2 to 200 km and has been focused on extreme events with deep convection. Suitable measures of the changing of convection in the presence of orography have been related to the physical properties of the rainfall environment. Preliminary results for the statistical variability of the convective field are presented.
A new strategy to modify the R-C equilibrium approach and to adapt it to WAM conditions including... more A new strategy to modify the R-C equilibrium approach and to adapt it to WAM conditions including a forcing provided by the 2D idealized model of Peyrillé and Lafore (2007) has been adopted to start a study of convection in the WAM region (monsoonal area). These simulations have been compared with 3D numerical simulations of an atmosphere in RC equilibrium that can be used as control run for tropical convection. This approach can be used to study different states corresponding to different location of the WAM system.
Procedia Engineering, 2014
A numerical simulation of tropical atmosphere in radiative convective equilibrium has been carrie... more A numerical simulation of tropical atmosphere in radiative convective equilibrium has been carried out and water data in different phases have been analyzed. 3D data have been averaged in space and time using as energy variable to sort them the moist static energy, that is conserved for a moist atmosphere during adiabatic fluid parcel displacements. The block averaged MSE gives a measure of the moisture flux that is dominating at statistical equilibrium triggering strong convection. MSE block vertical integrals, that give a measure of humidity going from dry to moist columns, are used to sort block integrals of variables. If the distribution of rainfall and precipitable water is analyzed using this technique, a correspondence between the moisture flux and total precipitable water (TPW) variability is found. The associated aggregation of precipitation rate is analyzed and different statistical behavior of moist and dry regions of the atmosphere is found.
Atmospheric Science Letters, 2011
Tellus A, 1999
Possible connections between spatial patterns, of limited regional extent and identified in telec... more Possible connections between spatial patterns, of limited regional extent and identified in teleconnection patterns and in blocking climatology studies, with hemispheric planetary-wave activity modes defined by the wave amplitude index (WAI) are investigated. The WAI probability density function (PDF) for the northern extratropics winter fields is estimated and the sensitivity of the WAI distribution to the presence of low-frequency variability modes is evaluated by stratifying the available dataset according to the sign of blocking and teleconnection indices. It is found that low-frequency variability modes affect both the mean and the variance of the wave amplitude index. Both the positive phase of the North Atlantic Oscillation (NAO) and the negative phase of the Pacific North American pattern (PNA) are associated with an enhanced frequency of very large amplitude planetary waves. Furthermore, distributions characterised by a maximum corresponding to high WAI values also exhibit a large variance. Negative NAO and positive PNA influence the mean and the variance of WAI PDF in the opposite sense. Similar results are found when the blocking index is considered. WAI PDFs relative to highly blocked months are broader with a secondary maximum corresponding to very high WAI values.
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Papers by Paolina Cerlini