Publications associées à Atlas international des nuages

Measurement report: High Arctic aerosol hygroscopicity at sub- and supersaturated conditions during spring and summer

Aerosol hygroscopic growth and cloud droplet formation influence the radiation transfer budget of the atmosphere and thereby the climate. In the Arctic, these aerosol properties may have a more pronounced effect on the climate compared to the midlatitudes. ...

Copernicus Publications2023

Identification of snowfall microphysical processes from Eulerian vertical gradients of polarimetric radar variables

Alexis Berne, Etienne Gabriel Henri Vignon, Josué Etienne Gehring

Polarimetric radar systems are commonly used to study the microphysics of precipitation. While they offer continuous measurements with a large spatial coverage, retrieving information about the microphysical processes that govern the evolution of snowfall ...

COPERNICUS GESELLSCHAFT MBH2021

Leveraging meteorological radars to investigate the influence of atmospheric dynamics on snowfall microphysics

Josué Etienne Gehring

Precipitation is the result of a chain of meteorological processes ranging from the large- to the micro-scale. While the transport of moisture and lifting mechanisms leading to cloud formation are mostly governed by dynamical processes, the formation and g ...

EPFL2021

Biomass burning aerosol as a modulator of the droplet number in the southeast Atlantic region

Athanasios Nenes

The southeastern Atlantic (SEA) and its associated cloud deck, off the west coast of central Africa, is an area where aerosol–cloud interactions can have a strong radiative impact. Seasonally, extensive biomass burning (BB) aerosol plumes from southern Afr ...

Copernicus Publications2020

Unraveling hydrometeor mixtures in polarimetric radar measurements

Alexis Berne, Jacopo Grazioli, Nikola Besic, Marco Gabella, Josué Etienne Gehring, Christophe Praz

Radar-based hydrometeor classification typically comes down to determining the dominant type of hydrometeor populating a given radar sampling volume. In this paper we address the subsequent problem of inferring the secondary hydrometeor types present in a ...

Copernicus GmbH2018

Hydrometeor classification through statistical clustering of polarimetric radar measurements: a semi-supervised approach

Alexis Berne, Jacopo Grazioli, Nikola Besic, Marco Gabella

Polarimetric radar-based hydrometeor classification is the procedure of identifying different types of hydrometeors by exploiting polarimetric radar observations. The main drawback of the existing supervised classification methods, mostly based on fuzzy lo ...

Copernicus GmbH2016

Hydrometeor classification from polarimetric radar measurements: a clustering approach

Alexis Berne, Devis Tuia, Jacopo Grazioli

A data-driven approach to the classification of hydrometeors from measurements collected with polarimetric weather radars is proposed. In a first step, the optimal number of hydrometeor classes (nopt) that can be reliably identified from a large set of pol ...

Copernicus Gesellschaft Mbh2015

Polarimetric weather radar : from signal processing to microphysical retrievals

Jacopo Grazioli

Accurate modelling of liquid, solid and mixed-phase precipitation requires a thorough understanding of phenomena occurring at various spatial and temporal scales. At the smallest scales, precipitation microphysics defines all the processes occurring at the ...

EPFL2015

Hydrometeor classification from two-dimensional video disdrometer data

Alexis Berne, Devis Tuia, Jacopo Grazioli, Marc Schneebeli Zeugin, Timothy Hugh Raupach

The first hydrometeor classification technique based on two-dimensional video disdrometer (2DVD) data is presented. The method provides an estimate of the dominant hydrometeor type falling over time intervals of 60 s during precipitation, using the statist ...

European Geosciences Union2014