Search results for "Atmospheric"
showing 10 items of 5755 documents
Sensitivity of a mesoscale model to different convective parameterization schemes in a heavy rain event
2011
Abstract. The Valencia region, on the Mediterranean coast of the Iberian Peninsula, is propitious to heavy precipitation, especially the area encompassing the South of Valencia province and the North of the Alicante province. In October 2007 a torrential rain affected the aforementioned area, producing accumulated rainfall values greater than 400 mm in less than 24 h and flash-floods that caused extensive economic losses and human casualties. This rain event has been studied in numerical experiments using the Regional Atmospheric Modeling System. The present paper deals with the effect of using the different convective parameterizations (CP) currently implemented in the Regional Atmospheric…
Analysis of the energy balance closure over a FLUXNET boreal forest in Finland
2010
Abstract. The imbalance in the surface energy budget, when using eddy-covariance techniques to measure turbulent fluxes, is still an unresolved problem. Important progresses have been reported in recent years identifying potential reasons for this lack of energy balance closure. In this paper we focus on the data collected in a FLUXNET boreal forest site in Sodankylä, Finland. Using one month half-hourly data, an average Energy Balance Ratio (EBR) of 0.72 is obtained. The inclusion of the heat storage terms in the energy budget yields an improvement of about 6% in the total closure. The sensitivity of the energy balance closure to the turbulence intensity is analysed in terms of the frictio…
Hot water injection in relation to 1982-84 microseismic events at Campi Flegrei Caldera by thermo-hydro-mechanical simulation
2020
The repeated deformations and seismic unrests at Campi Flegrei caldera (southern Italy) have been identified due to a fluid injection source in volcano active area. We investigated the role of hot water injection in the seismic unrests of 1982-1984 with a view to gaining insights into the caldera’s dynamics, by applying coupled TOUGHREACT-FLAC3D simulator to our computational domain of 10 × 1 × 3 km with a single-phase steam isothermal (HM) and non-isothermal (THM) simulations comparison. The results indicated that the overlying caprock blocks the uprising hot water injection, leading to the building up of pore pressure and shear stress underneath over time. This process substantially modif…
Including vegetation dynamics in an atmospheric chemistry-enabled general circulation model: linking LPJ-GUESS (v4.0) with the EMAC modelling system …
2020
Central to the development of Earth system models (ESMs) has been the coupling of previously separate model types, such as ocean, atmospheric, and vegetation models, to address interactive feedbacks between the system components. A modelling framework which combines a detailed representation of these components, including vegetation and other land surface processes, enables the study of land–atmosphere feedbacks under global climate change. Here we present the initial steps of coupling LPJ-GUESS, a dynamic global vegetation model, to the atmospheric chemistry-enabled atmosphere–ocean general circulation model EMAC. The LPJ-GUESS framework is based on ecophysiological processes, such as phot…
Sensitivity of aerosol radiative effects to different mixing assumptions in the AEROPT 1.0 submodel of the EMAC atmospheric-chemistry–climate model
2014
Abstract. The modelling of aerosol radiative forcing is a major cause of uncertainty in the assessment of global and regional atmospheric energy budgets and climate change. One reason is the strong dependence of the aerosol optical properties on the mixing state of aerosol components, such as absorbing black carbon and, predominantly scattering sulfates. Using a new column version of the aerosol optical properties and radiative-transfer code of the ECHAM/MESSy atmospheric-chemistry–climate model (EMAC), we study the radiative transfer applying various mixing states. The aerosol optics code builds on the AEROPT (AERosol OPTical properties) submodel, which assumes homogeneous internal mixing …
Climate and extreme rainfall events in the Mono river basin (West Africa): investigating future changes with Regional Climate Models.
2020
This study characterizes the future changes in extreme rainfall and air temperature in the Mono river basin where the main economic activity is weather dependent and local populations are highly vulnerable to natural hazards, including flood inundations. Daily precipitation and temperature from observational datasets and Regional Climate Models (RCMs) output from REMO, RegCM, HadRM3, and RCA were used to analyze climatic variations in space and time, and fit a GEV model to investigate the extreme rainfalls and their return periods. The results indicate that the realism of the simulated climate in this domain is mainly controlled by the choice of the RCMs. These RCMs projected a 1 to 1.5 °
Tsunami Propagation and Flooding in Sicilian Coastal Areas by Means of a Weakly Dispersive Boussinesq Model
2020
This paper addresses the tsunami propagation and subsequent coastal areas flooding by means of a depth-integrated numerical model. Such an approach is fundamental in order to assess the inundation hazard in coastal areas generated by seismogenic tsunami. In this study we adopted, an interdisciplinary approach, in order to consider the tsunami propagation, relates both to geomorphological characteristics of the coast and the bathymetry. In order to validate the numerical model, comparisons with results of other studies were performed. This manuscript presents first applicative results achieved using the weakly dispersive Boussinesq model in the field of tsunami propagation and coastal inunda…
Experimental Analysis of Velocity Distribution in a Coarse-Grained Debris Flow: A Modified Bagnold’s Equation
2020
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High-resolution orthophoto map and digital surface models of the largest Argentine Islands (the Antarctic) from unmanned aerial vehicle photogrammetry
2020
This study presents the first high-resolution orthophoto maps and digital surface models (DSMs) of the largest Argentine Islands, West Antarctica. Aerial surveys with small unmanned aerial vehicle (UAV) were performed in Austral summer, 2018, taking 10,041 aerial photographs. Accuracy requirements were ensured using ground control points (GCPs). A resolution of 3.4 and 6.8 cm/px of orthomosaics and DSMs is reached on average, and the RMS reprojection error is 0.22 m on average. We report the morphometric parameters of surveyed islands and discuss issues related to accuracy and the usage of UAVs in polar conditions. This study demonstrates that small and low cost UAVs can be successfully use…
Geomorphology and surface geology of Mount St. Helens volcano
2020
Mount St. Helens is a stratovolcano of the Cascadia volcanic arc well known worldwide for its volcanic collapse and eruption in 1980, which caused considerable destruction and changed the geomorphology of the volcano and of a considerable portion of its surroundings. This paper presents a geomorphology and surface-geology map of both the wider Mount St. Helens, Washington (USA), at the 1:50,000 scale, and of its crater, at the 1:25,000 scale. The map is obtained from the interpretation of two high-resolution, air-borne acquired, digital terrain models, LiDAR dataset, combined with Google Earth imaging, geological information and field surveys. The geomorphology of the area is largely domina…