A dataset of tracer concentrations and meteorological observations from the Bolzano Tracer EXperiment (BTEX) to characterize pollutant dispersion processes in an Alpine valley

Abstract. The paper describes the dataset of concentrations and related meteorological measurements collected during the field campaign of the Bolzano Tracer Experiment (BTEX). The experiment was performed to characterize the dispersion of pollutants emitted from a waste incinerator in the basin of the city of Bolzano, in the Italian Alps. As part of the experiment, two controlled releases of a passive gas tracer (sulfur hexafluoride, SF6) were performed through the stack of the incinerator on 14 February 2017 for two different time lags, starting, respectively, at 07:00 and 12:45 LST. Samples of ambient air were collected at target sites with vacuum-filled glass bottles and polyvinyl fluoride bags, and they were later analyzed by means of a mass spectrometer (detectability limit 30 pptv). Meteorological conditions were monitored by a network of 15 surface weather stations, 1 microwave temperature profiler, 1 sodar and 1 Doppler wind lidar. The dataset represents one of the few examples available in the literature concerning dispersion processes in a typical mountain valley environment, and it provides a useful benchmark for testing atmospheric dispersion models in complex terrain. The dataset described in this paper is available at https://doi.org/10.1594/PANGAEA.898761 (Falocchi et al., 2019)

On the stability of a nonlinear nonhomogeneous multiply hinged beam

The paper deals with a nonlinear evolution equation describing the dynamics of a nonhomogeneous multiply hinged beam, subject to a nonlocal restoring force of displacement type. First, a spectral analysis for the associated weighted stationary problem is performed, providing a complete system of eigenfunctions. Then, a linear stability analysis for bimodal solutions of the evolution problem is carried out, with the final goal of suggesting optimal choices of the density and of the position of the internal hinged points in order to improve the stability of the beam. The analysis exploits both analytical and numerical methods; the main conclusion of the investigation is that nonhomogeneous density functions improve the stability of the structure

Estimate of turbulent fluxes with eddy-covariance technique in a complex topography: A case study in the Italian Alps

A sensitivity analysis to different eddy—covariance data processing algorithms is presented for a dataset collected in an Alpine environment with complex topography. In Summer 2012 a micrometeorological station was installed at Cividate Camuno (274 m a.s.l., Oglio river basin, Central Italian Alps), in a flat and rectangular grass-covered lawn. The grass was 0.6 m tall during most of the field campaign. The station is equipped with traditional devices, four multiplexed TDR probes, and an eddy--covariance apparatus sampling at 20 Hz (Gill WindMaster Sonic Anemometer and Licor Li7500 Gas Analyzer), at about 3 m above the ground. The local winds regime is strongly affected by the morphology of the valley, and the topography is complex also due to the heterogeneity of the surrounding-areas land—cover. Using EddyPro software, the sensitivity of the turbulent fluxes estimate was assessed addressing three major issues of the data processing procedure, i.e. the choice of the computational averaging period, of the axis rotation method and of the data detrending criterion. Once identified three test periods of consecutive days without rainfall, the fluxes of momentum, sensible heat and latent heat were computed at the averaging period of 30, 60 and 120 min respectively. At each averaging period, both the triple rotation method, the double rotation method and the planar fit method were applied. Particularly the latter was applied both fitting a unique plane for all the wind directions and fitting multiple planes, one for each sector of the wind rose. Regarding the detrending criteria, data were processed with a block average and a linear detrend, the latter with time constant of 5, 30, 60 and 120 min respectively. Therefore, for each test period about 50 estimates of the fluxes were provided. As a result the obtained fluxes were compared. Even if with different flux quality, their pattern is quite stable with regard to the applied estimate procedures, but with sensitively different average values

Turbulence measurements in an Alpine valley: The CividatEX Experiment case

Mountain Hydrology, Eddy Covariance, Evapotraspiratio

PRELIMINARY RESULTS ON THE GLACIAL WINDS REGIME OF THE MANDRONE GLACIER

During the summer of 2008, from 13 June to 29 September, at an altitude of 2780 m asl, a micrometeorological station was placed on the Mandrone Glacier (Adamello Group, Italian Central Alps) by a team of the University of Brescia. The aim of the MandronEX (Mandrone EXperiment) field campaign was the collection of useful data to analyse the glacial winds and estimate the mass balance of the glacier. In this study will the data recorded by the 3 axes Gill WindMaster sonic anemometer at a sampling rate of 20 Hz, during the first nine days of the experiment will be analysed, in order to detect the glacial winds. A general description of the atmospheric pressure, the air temperature and the wind directions was provided in order to understand the meteorological conditions on the glacier and to obtain preliminary information about the winds regime. The more accurate elaborations executed by means of the frequency analysis and the wind–roses have shown an alternate regime of anabatic winds, from the valley to the glacier, especially in the first days of the campaign, and katabatic ones from the glacier to the valley. The spectral analysis of the u and w wind speed components, instead, allowed to detect the presence of the -5/3 slope Kolmogorov law, in the inertial sub–range. Moreover, according to the analysis provided by Kaimal et al. (1972) the atmosphere seems to be stable during the investigated period

Assessment of the Water Balance in an Alpine Climate: Setup of a Micrometeorological Station and Preliminary Results

An experimental field campaign was performed during summer 2012 in an Alpine environment (Cividate Camuno, Oglio river basin, 274 m a.s.l.) in order to assess the water balance of an anthropized soil at the local scale. A micrometeorological station equipped with traditional sensors coupled with eddy covariance apparatus and TDR was installed in order to measure precipitation, evapotranspiration and soil—water content at different depths. The soil water properties were determined after field and laboratory investigations. Here the preliminary results of the campaign are presented and discussed, focusing on the assessment of the evapotranspiration and of the water exchanges in the vadose zone as ones of the major problems of water imbalance

Elasticity solution for a hollow cylinder under axial end loads: Application to a blister of a stayed bridge

Starting from an applied problem related to the modeling of an element of a cable-stayed bridge, we compute the elasticity solution for a hollow circular cylinder under axial end loads. We prove results of symmetry for the solution and we expand it in proper Fourier series; computing the Fourier coefficients in adapted power series, we provide the explicit solution. We consider an engineering case of study, applying the corresponding approximate formula and giving some estimates on the error committed with respect to the truncation of the series

Elasticity solution for a hollow cylinder under axial end loads: Application to a blister of a stayed bridge

Starting from an applied problem related to the modeling of an element of a cable-stayed bridge, we compute the elasticity solution for a hollow circular cylinder under axial end loads. We prove results of symmetry for the solution and we expand it in proper Fourier series; computing the Fourier coefficients in adapted power series, we provide the explicit solution. We consider an engineering case of study, applying the corresponding approximate formula and giving some estimates on the error committed with respect to the truncation of the series