Publications related to Hook echo

Supercell Thunderstorms in the Alpine Region - From Weather Radar Observations to Idealized Modeling

The high-impact nature and increasing occurrence of severe weather phenomena pushes forward research on their occurrence and improving our understanding thereof. Supercell thunderstorms are the focus of much severe convective research, as they represent on ...

EPFL2023

Snowfall microphysics: a dual-frequency and Doppler spectral radar perspective

Anne-Claire Marie Billault--Roux

Snowfall is an essential component of the hydrological cycle, as it is involved in most precipitation on Earth, either directly as snow falling to the ground or indirectly as rain melted from snow. At the same time, the ice phase of clouds and precipitatio ...

EPFL2023

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

Cavity-assisted preparation and detection of a unitary Fermi gas

Jean-Philippe Brantut, Victor Youri Helson, Kevin Etienne Robert Roux, Hideki Konishi

We report on the fast production and weakly destructive detection of a Fermi gas with tunable interactions in a high finesse cavity. The cavity is used both with far off-resonant light to create a deep optical dipole trap, and with near-resonant light to r ...

2021

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

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

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

Nowcasting lightning occurrence from commonly available meteorological parameters using machine learning techniques

Farhad Rachidi-Haeri, Marcos Rubinstein, Amirhossein Mostajabi

Article Open Access Published: 08 November 2019 Nowcasting lightning occurrence from commonly available meteorological parameters using machine learning techniques Amirhossein Mostajabi, Declan L. Finney, Marcos Rubinstein & Farhad Rachidi npj Climate and ...

2019

Evaluation of global simulations of aerosol particle and cloud condensation nuclei number, with implications for cloud droplet formation

Athanasios Nenes, Julia Schmale, Yang Yang

A total of 16 global chemistry transport models and general circulation models have participated in this study; 14 models have been evaluated with regard to their ability to reproduce the near-surface observed number concentration of aerosol particles and ...

Copernicus Publications2019

Deployment and Performance Analyses of High-Resolution Iowa XPOL Radar System during the NASA IFloodS Campaign

Jacopo Grazioli, Kumar Vijay Mishra

This article presents the data collected and analyzed using the University of Iowa's X-band polarimetric (XPOL) radars that were part of the spring 2013 hydrology-oriented Iowa Flood Studies (IFloodS) field campaign, sponsored by NASA's Global Precipitatio ...

American Meteorological Society2016

Understanding Small Scale Variability of the Mountain Snow Cover

In mountains the snow cover is heterogeneously distributed in space and time. The spatial and temporal variability of the Alpine snow cover has a major influence on avalanche danger, snow hydrology, mountain ecology and winter tourism. In winter, already d ...

EPFL2011

Effects of Swirl Velocities From Fan Assemblies Mounted on Lifting Surfaces

Alexandros Terzis, Charilaos Kazakos, Nikolaos Papadopoulos

The penetration of a jet of fluid into a traversal moving stream is a basic configuration of a wide range of engineering applications, such as film cooling and V/STOL aircrafts. This investigation examines experimentally the effect of blowing ratio of fans ...

2011