arXiv subjects

Andrea Merlone

Publications and source records attributed to Andrea Merlone.

3 recordsLinked to original sources

arXiv2023

Validation and traceability of miniaturized multi-parameter cluster of radiosondes used for atmospheric observations

In this work we designed and developed a cluster of light expendable radiosondes that can float passively inside warm clouds to study their micro-physical processes. This involves the tracking of both saturated and unsaturated turbulent air parcels. The aim of this new kind of observation system is to obtain Lagrangian statistics of the intense turbulence inside warm clouds and of the lower intensity turbulence that is typical of the air surrounding such clouds. Each radiosonde in a cluster includes an electronic board, which is mounted onto a small, biodegradable balloon filled with a mixture of helium and air. The cluster is able to float inside clouds for a few hours and to measure air temperature, pressure, humidity and the associated position, velocity, acceleration and magnetic field readings of each radiosonde along their trajectory.

eess.SY↗

arXiv2021

Innovative mini ultralight radiosondes to track Lagrangian turbulence fluctuations within warm clouds: electronic design

Characterization of cloud properties remains a challenging task for weather forecasting and climate modelling as cloud properties depend on interdependent natural processes at micro and macro scales. Turbulence plays an important role in particle dynamics inside clouds; however, turbulence mechanisms are not yet fully understood partly due to the difficulty of measuring clouds at the smallest scales. To address these knowledge gaps, an experimental method for measuring the influence of fine-scale turbulence in cloud formation in-situ and producing an in-field cloud Lagrangian dataset is being developed by means of innovative ultra-light radioprobes. This paper presents the electronic system design along with the obtained results from laboratory and field experiments regarding these compact (diameter about 30 cm), light-weight (about 20 g), and expendable devices designed to passively float and track small-scale turbulence fluctuations inside warm clouds. The fully customized mini radioprobe board (5 cm x 5 cm) embeds sensors to measure local fluctuations and transmit data to the ground in near real-time. The tests confirm that the newly developed probes perform well providing accurate information about atmospheric variables, referenced in space. The integration of multiple radioprobes allows for a systematic and accurate monitoring of atmospheric turbulence and its impact on cloud formation.

physics.ao-ph↗

arXiv2019

Evaluation of Mater Bi and Polylactic Acid as materials for biodegradable innovative mini-radiosondes to track small scale fluctuations within clouds

Turbulence plays an important part in determining the chemical and physical processes, on both the micro- and macro-scales, whereby clouds are formed and behave. However, exactly how these are linked together and how turbulence impacts each of these processes is not yet fully understood. This is partly due to a lack of in-situ small scale fluctuation measurements due to a limitation in the available technology. It is in this context that the radiosondes, for which the material characterisation is presented in this paper, are being developed to generate a Lagrangian set of data which can be used to improve the ever-expanding knowledge of atmospheric processes and, in particular, the understanding of the interaction between turbulence and micro-physical phenomenologies inside clouds (www.complete-h2020network.eu). Specifically, the materials developed for the balloons are discussed in further detail within this paper. Mater Bi and polylactic acid are the two common biodegradable thermoplastics that were used initially to make the balloons. To tailor their properties, the balloons were then coated with carnauba wax blended with either pine resin or SiO_2 nanoparticles. The properties such as hydrophobicity, toughness, elasticity and helium gas permeability are investigated and improved in order to keep the density of the radiosondes as constant as possible for a couple of hours. This will allow them to float inside and outside clouds on an isopycnic surface, to measure various properties such as velocity, temperature, pressure and humidity by means of solid state sensors and to transmit them to receivers on Earth. Tests have been made under a rigorous metrological approach comparing the 6 new materials with two reference balloon materials, latex and mylar. It was found that Mater Bi with the two carnaubua wax coatings is the most suited..

physics.ao-ph↗