Publications associées à Signature tornadique de rotation

Wind Transport of Snow Impacts Ka- and Ku-band Radar Signatures on Arctic Sea Ice

Marc Schneebeli Zeugin, David Nicholas Wagner

Wind transport alters the snow topography and microstructure on sea ice through snow redistribution controlled by deposition and erosion. The impact of these processes on radar signatures is poorly understood. Here, we examine the effects of snow redistrib ...

2023

A Characterisation of Alpine Mesocyclone Occurrence

Alexis Berne, Marco Gabella, Monika Feldmann, Urs Martin Germann

This work presents a characterisation of mesocyclone occurrence and frequency in the Alpine region, as observed from the Swiss operational radar network; 5 years of radar data are processed with a thunderstorm detection and tracking algorithm and subsequen ...

2021

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

Alexis Berne, Josué Etienne Gehring, Etienne Gabriel Henri Vignon, Noémie Planat

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

Characteristics of different charge transfer modes in upward flashes inferred from simultaneously measured currents and fields

Marcos Rubinstein, Mohammad Azadifar, Farhad Rachidi-Haeri, Davide Pavanello, Lixia He, Qi Li

The authors present an analysis of different charge transfer modes during upward negative flashes. The analysis includes a total number of 94 pulses that occurred during two upward negative flashes recorded at the Säntis Tower. The pulses included 59 mixed ...

2020

Polarimetric radar characteristics of lightning initiation and propagating channels

Marcos Rubinstein, Antonio Sunjerga, Farhad Rachidi-Haeri, Mohammad Azadifar, Amirhossein Mostajabi, Jacopo Grazioli, Nikola Besic, Urs Martin Germann

In this paper we present an analysis of a large dataset of lightning and polarimetric weather radar data collected in the course of a lightning measurement campaign that took place in the summer of 2017 in the area surrounding Säntis, in the northeastern p ...

2019

Statistical analysis of the spatial and temporal variability of polarimetric weather radar signals in the Alps

Floortje Elisabeth Maria Van den Heuvel

The accurate estimation of precipitation quantities arriving at the ground in complex terrain such as the Alps is complicated by many factors. The orography interacts with atmospheric flow and thus influences the spatial and temporal distribution as well a ...

EPFL2019

Modeling of Different Charge Transfer Modes in Upward Flashes Constrained by Simultaneously Measured Currents and Fields

Mario Paolone, Marcos Rubinstein, Mohammad Azadifar, Farhad Rachidi-Haeri, Davide Pavanello, Lixia He, Qi Li

The purpose of the paper is to investigate charge transfer modes in upward lightning flashes by means of numerical simulation constrained by concurrent observations of electromagnetic fields and currents. In particular, we focus on different types of pulse ...

2018

Characterisation of the melting layer variability in an Alpine valley based on polarimetric X-band radar scans

Alexis Berne, Floortje Elisabeth Maria Van den Heuvel, Marco Gabella, Urs Martin Germann

The melting layer designates the transition region from solid to liquid precipitation, and is a typical feature of the vertical structure of stratiform precipitation. As it is characterised by a well-known signature in polarimetric radar variables, it can ...

COPERNICUS GESELLSCHAFT MBH2018

From model to radar variables: a new forward polarimetric radar operator for COSMO

Alexis Berne, Daniel Wolfensberger

In this work, a new forward polarimetric radar operator for the COSMO numerical weather prediction (NWP) model is proposed. This operator is able to simulate measurements of radar reflectivity at horizontal polarization, differential reflectivity as well a ...

Copernicus GmbH2018

A polarimetric radar operator to evaluate precipitation from the COSMO atmospheric model

Daniel Wolfensberger

Weather radars provide real-time measurements of precipitation at a high temporal and spatial resolution and over a large domain. A drawback, however, it that these measurements are indirect and require careful interpretation to yield relevant information ...

EPFL2018