24 research outputs found
Predictability studies for Regions Of Freshwater Influence
The aim of this study is to understand and to assess the effects of river freshwater inflow on the circulation and dynamics of our region of interest, the Central Mediterranean Sea, both on shelf and basin scales, over short-term as well as long-term range.
As far as we know this study provides the first investigation on river role on the Central Mediterranean overturning circulation.
On the same time we point to improve the hindcast/forecast capability of our regional hydrodynamics model both on shelf and basin scales through a consistent representation of river inflow into the Central Mediterranean Sea taking not account all the physical processes involved in the local water cycle of specific catchments. An integrated modelling system including the atmosphere, the hydrology and the estuary dynamics has been set up upstream the regional ocean model at the Ofanto river outlet. The Estuary Box Model developed by the University of Connecticut (UCONN) jointly with the National Centre for the Atmospheric Research (NCAR) Climate Global Division and the University of Washington (UW) has been implemented for the selected case study, the Ofanto river, downstream of the meteo-hydrological chain and upstream of the regional ocean model. The model performance has been evaluated by comparison with a highly simplified approach based on Knudsenâs relation (Knudsen, 1900). Finally we built up an intermediate modelling approach
A meteo-hydrological modelling system for the reconstruction of river runoff: the case of the Ofanto river catchment
Abstract. A meteo-hydrological modelling system has been designed for the reconstruction of long time series of rainfall and river runoff events. The modelling chain consists of the mesoscale meteorological model of the Weather Research and Forecasting (WRF), the land surface model NOAH-MP and the hydrologyâhydraulics model WRF-Hydro. Two 3-month periods are reconstructed for winter 2011 and autumn 2013, containing heavy rainfall and river flooding events. Several sensitivity tests were performed along with an assessment of which tunable parameters, numerical choices and forcing data most impacted on the modelling performance.The calibration of the experiments highlighted that the infiltration and aquifer coefficients should be considered as seasonally dependent.The WRF precipitation was validated by a comparison with rain gauges in the Ofanto basin. The WRF model was demonstrated to be sensitive to the initialization time and a spin-up of about 1.5 days was needed before the start of the major rainfall events in order to improve the accuracy of the reconstruction. However, this was not sufficient and an optimal interpolation method was developed to correct the precipitation simulation. It is based on an objective analysis (OA) and a least square (LS) melding scheme, collectively named OA+LS. We demonstrated that the OA+LS method is a powerful tool to reduce the precipitation uncertainties and produce a lower error precipitation reconstruction that itself generates a better river discharge time series. The validation of the river streamflow showed promising statistical indices.The final set-up of our meteo-hydrological modelling system was able to realistically reconstruct the local rainfall and the Ofanto hydrograph
A meteo-hydrological modelling system for the reconstruction of river runoff: the case of the Ofanto river catchment
A meteo-hydrological modelling system has been designed for the reconstruction of long time series of rainfall and river runoff events. The modelling chain consists of the mesoscale meteorological model of the Weather Research and Forecasting (WRF), the land surface model NOAH-MP and the hydrology-hydraulics model WRF-Hydro. Two 3-month periods are reconstructed for winter 2011 and autumn 2013, containing heavy rainfall and river flooding events. Several sensitivity tests were performed along with an assessment of which tunable parameters, numerical choices and forcing data most impacted on the modelling performance. The calibration of the experiments highlighted that the infiltration and aquifer coefficients should be considered as seasonally dependent. The WRF precipitation was validated by a comparison with rain gauges in the Ofanto basin. The WRF model was demonstrated to be sensitive to the initialization time and a spin-up of about 1.5 days was needed before the start of the major rainfall events in order to improve the accuracy of the reconstruction. However, this was not sufficient and an optimal interpolation method was developed to correct the precipitation simulation. It is based on an objective analysis (OA) and a least square (LS) melding scheme, collectively named OA+LS. We demonstrated that the OA+LS method is a powerful tool to reduce the precipitation uncertainties and produce a lower error precipitation reconstruction that itself generates a better river discharge time series. The validation of the river streamflow showed promising statistical indices. The final set-up of our meteo-hydrological modelling system was able to realistically reconstruct the local rainfall and the Ofanto hydrograph
A box model to represent estuarine dynamics in mesoscale resolution ocean models
Representing the net freshwater flux at river mouths is challenging for global and regional scale ocean modelling. Although rivers are well known to affect both the coastal and basin-wide circulation and dynamics, coarse resolution ocean models cannot resolve the estuarine dynamics and are usually forced at river outlets in a simplistic way, with climatological runoff and zero or constant salinity values. The aim of this study is to provide a more realistic representation of the estuarine water inputs to a coarse but eddy-resolving regional model. First, the river volume transport and salinity values at the outlets are modelled with three different Estuary Box Models (EBMs) for stratified estuaries: the Knudsen relations model, a published EBM, called UCONN-NCAR EBM, which parameterizes the tidal inflow and mixing inside the estuary, and a new model, called CMCC-EBM. The CMCC EBM has been conceived to represent the estuarine processes coupled to a mesoscale resolving hydrodynamic model that resolves the entering flow field at the estuary mouth and it offers a new representation of the tidal inflow and a new salinity tidal mixing parameterization via horizontal diffusive processes. The Ofanto and Po rivers flowing into the Adriatic Sea (northern part of the central Mediterranean Sea) are selected as case studies. The coupling of the eddy resolving ocean model to the CMCC EBM is found to outperform the one with the UCONN-NCAR EBM in the region of freshwater influence on the shelf area
Projected climate oligotrophication of the Adriatic marine ecosystems
The Adriatic Sea hosts diverse marine ecosystems, characterized by rich biodiversity and unique ecological dynamics. Its intricate coastal habitats and open waters support a range of species and contribute to the region's ecological and economic significance. Unraveling the consequences of the ongoing climate changes on this delicate environment is essential to ensure the future safeguard of this basin. To tackle this problem, we developed a biogeochemical model for the entire basin, with a horizontal resolution of about 2 km and 120 vertical levels, forced by the projections of atmosphere, hydrology and ocean circulation between 1992 and 2050, under emission scenario RCP8.5. The changes projected between 2031â2050 and 1992â2011 were evaluated on ecoregions characterized by different trophic conditions, identified using a k-medoid classification technique. The results point toward a generalized oligotrophication of the basin, especially intense in the northern estuarine areas, driven by a substantial decrease in river discharge projected for the rivers of the Po Plain. This scenario of unproductive and declining resources, together with the ongoing warming, salinization, and acidification of marine waters, cast doubt on the long-term resilience of the Northern Adriatic food web structure, which has evolved to thrive in high trophic conditions. The outcome of this study provides the stakeholders with a tool to understand how potential long-term decreases in the regimes of the Northern Adriatic Rivers could affect the marine ecosystem and its goods and services in the future
On the management of nature-based solutions in open-air laboratories: new insights and future perspectives
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SeaConditions: a web and mobile service for safer professional and recreational activities in the Mediterranean Sea
Abstract. Reliable and timely information on the environmental conditions at sea is key to the safety of professional and recreational users as well as to the optimal execution of their activities. The possibility of users obtaining environmental information in due time and with adequate accuracy in the marine and coastal environment is defined as sea situational awareness (SSA). Without adequate information on the environmental meteorological and oceanographic conditions, users have a limited capacity to respond, which has led to loss of lives and to large environmental disasters with enormous consequent damage to the economy, society and ecosystems. Within the framework of the TESSA project, new SSA services for the Mediterranean Sea have been developed. In this paper we present SeaConditions, which is a web and mobile application for the provision of meteorological and oceanographic observation and forecasting products. Model forecasts and satellite products from operational services, such as ECMWF and CMEMS, can be visualized in SeaConditions. In addition, layers of information related to bathymetry, sea level and ocean-colour data (chl a and water transparency) are displayed. Ocean forecasts at high spatial resolutions are included in the version of SeaConditions presented here. SeaConditions provides a user-friendly experience with a fluid zoom capability, facilitating the appropriate display of data with different levels of detail. SeaConditions is a single point of access to interactive maps from different geophysical fields, providing high-quality information based on advanced oceanographic models. The SeaConditions services are available through both web and mobile applications. The web application is available at www.sea-conditions.com and is accessible and compatible with present-day browsers. Interoperability with GIS software is implemented. User feedback has been collected and taken into account in order to improve the service. The SeaConditions iOS and Android apps have been downloaded by more than 105âŻ000 users to date (May 2016), and more than 100âŻ000 users have visited the web version
Sex difference and intra-operative tidal volume: Insights from the LAS VEGAS study
BACKGROUND: One key element of lung-protective ventilation is the use of a low tidal volume (VT). A sex difference in use of low tidal volume ventilation (LTVV) has been described in critically ill ICU patients.OBJECTIVES: The aim of this study was to determine whether a sex difference in use of LTVV also exists in operating room patients, and if present what factors drive this difference.DESIGN, PATIENTS AND SETTING: This is a posthoc analysis of LAS VEGAS, a 1-week worldwide observational study in adults requiring intra-operative ventilation during general anaesthesia for surgery in 146 hospitals in 29 countries.MAIN OUTCOME MEASURES: Women and men were compared with respect to use of LTVV, defined as VT of 8âmlâkg-1 or less predicted bodyweight (PBW). A VT was deemed 'default' if the set VT was a round number. A mediation analysis assessed which factors may explain the sex difference in use of LTVV during intra-operative ventilation.RESULTS: This analysis includes 9864 patients, of whom 5425 (55%) were women. A default VT was often set, both in women and men; mode VT was 500âml. Median [IQR] VT was higher in women than in men (8.6 [7.7 to 9.6] vs. 7.6 [6.8 to 8.4] mlâkg-1 PBW, Pâ<â0.001). Compared with men, women were twice as likely not to receive LTVV [68.8 vs. 36.0%; relative risk ratio 2.1 (95% CI 1.9 to 2.1), Pâ<â0.001]. In the mediation analysis, patients' height and actual body weight (ABW) explained 81 and 18% of the sex difference in use of LTVV, respectively; it was not explained by the use of a default VT.CONCLUSION: In this worldwide cohort of patients receiving intra-operative ventilation during general anaesthesia for surgery, women received a higher VT than men during intra-operative ventilation. The risk for a female not to receive LTVV during surgery was double that of males. Height and ABW were the two mediators of the sex difference in use of LTVV.TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov, NCT01601223
CMCC-Hybrid-EstuaryBoxModel
<p>The software is related to the development and implementation of the CMCC-Hybrid-EstuaryBoxModel (CMCC-Hybrid-EBM v1.0). The CMCC-Hybrid-EBM represents an advancement of the CMCC-EBM model, thanks to the integration of a machine learning-based approach. The CMCC-Hybrid-EBM is formally described in the manuscript by Maglietta et al., titled 'Advancing Estuarine Box Modeling: a Novel Hybrid Machine Learning and Physics-Based Approach'. As of November 2023, this manuscript is currently under submission to Environmental Modelling & Software.</p>