Publications by Anne-Claire Marie Billault--Roux

What can radars tell us about snowfall microphysics? Insights from a Markov chain Monte-Carlo approach

Alexis Berne, Anne-Claire Marie Billault--Roux

Multi-frequency and Doppler spectral radars are valuable tools for retrieving information on the microphysics of precipitation, particularly snowfall. However, estimating microphysical properties from radar measurements is an ill-posed problem, i.e., diffe ...

American Meteorological Society2025

Attribution of riming and aggregation processes by application of the vertical distribution of particle shape (VDPS) and spectral retrieval techniques to cloud radar observations

Anne-Claire Marie Billault--Roux

Advancing the understanding of mixed-phase cloud microphysical growth processes requires a thorough detection of the transition processes from pristine hydrometeor states toward aggregates, rimed particles and graupel. In this study, a versatile combinatio ...

COPERNICUS GESELLSCHAFT MBH2025

Unraveling ice multiplication in winter orographic clouds via in-situ observations, remote sensing and modeling

Alexis Berne, Satoshi Takahama, Athanasios Nenes, Georgia Sotiropoulou, Anne-Claire Marie Billault--Roux, Paraskevi Georgakaki, Romanos Foskinis, Kunfeng Gao

Recent years have shown that secondary ice production (SIP) is ubiquitous, affecting all clouds from polar to tropical regions. SIP is not described well in models and may explain biases in warm mixed-phase cloud ice content and structure. Through modeling ...

Nature Portfolio2024

Biological and dust aerosols as sources of ice-nucleating particles in the eastern Mediterranean: Source apportionment, atmospheric processing and parameterization

Alexis Berne, Athanasios Nenes, Anne-Claire Marie Billault--Roux, Paraskevi Georgakaki, Romanos Foskinis, Kunfeng Gao

Aerosol-cloud interactions in mixed-phase clouds (MPCs) are one of the most uncertain drivers of the hydrological cycle and climate change. A synergy of in situ, remote-sensing and modelling experiments were used to determine the source of ice-nucleating p ...

Copernicus Publications2024

Data and scripts for "Unraveling secondary ice production in winter orographic clouds through a synergy of in-situ observations, remote sensing and modeling"

Alexis Berne, Satoshi Takahama, Athanasios Nenes, Georgia Sotiropoulou, Anne-Claire Marie Billault--Roux, Paraskevi Georgakaki, Romanos Foskinis, Kunfeng Gao

This repository contains field observations and processed data from the Weather Research and Forecasting (WRF) model simulations and the Cloud Resolving Model Radar Simulator (CR-SIM), alongside scripts designed to reproduce the figures presented in the pa ...

Zenodo2024

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

Distinct secondary ice production processes observed in radar Doppler spectra: insights from a case study

Alexis Berne, Athanasios Nenes, Anne-Claire Marie Billault--Roux, Paraskevi Georgakaki

Secondary ice production (SIP) has an essential role in cloud and precipitation microphysics. In recent years, substantial insights were gained into SIP by combining experimental, modeling, and observational approaches. Remote sensing instruments, among th ...

Copernicus Publications2023

Dual-frequency spectral radar retrieval of snowfall microphysics: a physics-driven deep-learning approach

Alexis Berne, Gionata Ghiggi, Anne-Claire Marie Billault--Roux

The use of meteorological radars to study snowfall microphysical properties and processes is well established, in particular via a few distinct techniques: the use of radar polarimetry, of multi-frequency radar measurements, and of the radar Doppler spectr ...

COPERNICUS GESELLSCHAFT MBH2023

Synergetic Aircraft and Ground-Based Remote Sensing and In Situ Measurements of Snowfall Microphysical Properties

Alexis Berne, Jacopo Grazioli, Anne-Claire Marie Billault--Roux

An international field experiment took place in the Swiss Jura in January 2021 as a milestone of the European ICE GENESIS project (www.ice-genesis.eu/), which aims to better measure, understand, and model the ice/snow particle properties and mechanisms res ...

2023

Calibration Transfer Methodology for Cloud Radars Based on Ice Cloud Observations

Alexis Berne, Anne-Claire Marie Billault--Roux

This article presents a calibration transfer methodology that can be used between radars of the same or dif-ferent frequency bands. This method enables the absolute calibration of a cloud radar by transferring it from another collocated instrument with kno ...

AMER METEOROLOGICAL SOC2023

ERUO: a spectral processing routine for the Micro Rain Radar PRO (MRR-PRO)

Alexis Berne, Alfonso Ferrone, Anne-Claire Marie Billault--Roux

The Micro Rain Radar PRO (MRR-PRO) is a K-band Doppler weather radar, using frequency-modulated continuous-wave (FMCW) signals, developed by Metek Meteorologische Messtechnik GmbH (Metek) as a successor to the MRR-2. Benefiting from four datasets collected ...

COPERNICUS GESELLSCHAFT MBH2022

Orographic Flow Influence on Precipitation During an Atmospheric River Event at Davis, Antarctica

Alexis Berne, Josué Etienne Gehring, Etienne Gabriel Henri Vignon, Alfonso Ferrone, Anne-Claire Marie Billault--Roux

Intense snowfall sublimation was observed during a precipitation event over Davis in the Vestfold Hills, East Antarctica, from 08 to 10 January 2019. Radar observations and simulations from the Weather Research and Forecasting model revealed that orographi ...

AMER GEOPHYSICAL UNION2022

MASCDB, a database of images, descriptors and microphysical properties of individual snowflakes in free fall

Alexis Berne, Jacopo Grazioli, Gionata Ghiggi, Anne-Claire Marie Billault--Roux

Snowfall information at the scale of individual particles is rare, difficult to gather, but fundamental for a better understanding of solid precipitation microphysics. In this article we present a dataset (with dedicated software) of in-situ measurements o ...

2022

Secondary ice production processes in wintertime alpine mixed-phase clouds

Alexis Berne, Athanasios Nenes, Georgia Sotiropoulou, Anne-Claire Marie Billault--Roux, Paraskevi Georgakaki

Observations of orographic mixed-phase clouds (MPCs) have long shown that measured ice crystal number concentrations (ICNCs) can exceed the concentration of ice nucleating particles by orders of magnitude. Additionally, model simulations of alpine clouds a ...

Copernicus GmbH2022

Integrated water vapor and liquid water path retrieval using a single-channel radiometer

Alexis Berne, Anne-Claire Marie Billault--Roux

Microwave radiometers are widely used for the retrieval of liquid water path (LWP) and integrated water vapor (IWV) in the context of cloud and precipitation studies. This paper presents a new site-independent retrieval algorithm for LWP and IWV, relying o ...

COPERNICUS GESELLSCHAFT MBH2021

Radar and ground-level measurements of precipitation collected by the Ecole Polytechnique Federale de Lausanne during the International Collaborative Experiments for PyeongChang 2018 Olympic and Paralympic winter games

Alexis Berne, Josué Etienne Gehring, Nikola Besic, Alfonso Ferrone, Anne-Claire Marie Billault--Roux

This article describes a 4-month dataset of precipitation and cloud measurements collected during the International Collaborative Experiments for PyeongChang 2018 Olympic and Paralympic winter games (ICE-POP 2018). This paper aims to describe the data coll ...

COPERNICUS GESELLSCHAFT MBH2021