Publications associées à Signature de débris de tornade

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

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

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

Dynamic Differential Reflectivity Calibration Using Vertical Profiles in Rain and Snow

Alexis Berne, Alfonso Ferrone

The accuracy required for a correct interpretation of differential reflectivity (ZDR) is typically estimated to be between 0.1 and 0.2 dB. This is achieved through calibration, defined as the identification of the constant or time-varying offset to be subt ...

2020

Learning about the vertical structure of radar reflectivity using hydrometeor classes and neural networks in the Swiss Alps

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

The use of radar for precipitation measurement in mountainous regions is complicated by many factors, especially beam shielding by terrain features, which, for example, reduces the visibility of the shallow precipitation systems during the cold season. Whe ...

2020

Microphysics and dynamics of snowfall associated with a warm conveyor belt over Korea

Alexis Berne, Josué Etienne Gehring, Nikola Besic, Etienne Gabriel Henri Vignon, Nicolas Jean François Jullien

On 28 February 2018, 57mm of precipitation associated with a warm conveyor belt (WCB) fell within 21 h over South Korea. To investigate how the large-scale circulation influenced the microphysics of this intense precipitation event, we used radar measureme ...

Copernicus Publications2020

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

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

Unraveling hydrometeor mixtures in polarimetric radar measurements

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

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

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