Publications related to Downburst

Nowcasting of High-Intensity Rainfall for Urban Applications in the Netherlands

Radar rainfall nowcasting has mostly been applied to relatively large (often rural) domains (e.g., river basins), although rainfall nowcasting in small urban areas is expected to be more challenging. Here, we selected 80 events with high rainfall intensiti ...

Amer Meteorological Soc2024

Seasonal variation in the xylem sap composition of six Australian trees and shrubs

Alice Jacqueline Frédérique Gauthey

In recent years, xylem sap composition has been shown to affect xylem hydraulics. However, information on how much xylem sap composition can vary across seasons and specifically under drought stress is still limited. We measured xylem sap chemical composit ...

Oxford Univ Press2023

Natural slicks on Lake Geneva: From small-scale effects to large-scale formation and distribution

Mehrshad Foroughan

Low wind speeds (< 4 m/s) are ubiquitous in many water bodies, yet the physical processes occurring at the air-water interface in this range are poorly understood. A notable example is smooth patches on the water surface, known as natural slicks, formed wh ...

EPFL2023

Lightning Nowcasting Using Solely Lightning Data

Farhad Rachidi-Haeri, Marcos Rubinstein, Amirhossein Mostajabi

Lightning is directly or indirectly responsible for significant human casualties and property damage worldwide. A timely prediction of its occurrence can enable authorities and the public to take necessary precautionary actions resulting in diminishing the ...

MDPI2023

Wind Defiant Morphing Drones

Dario Floreano, Charalampos Vourtsis, Victor Casas Rochel, Nathan Samuel Müller, William John Stewart

Intense winds are a challenge for vertical take-off and landing drones with wings. In particular, in the hovering regime, wings are sensitive to wind currents that can be detrimental to their operational and energetic performances. Tail-sitters are particu ...

2023

Wind Turbine Wakes in Active Yaw Control: Numerical and Theoretical Studies

Mou Lin

In this thesis, we explore the best practice of simulating the wakes of the turbines under active yaw control (AYC) using large-eddy simulation (LES). In the first study, we validate the blade-element actuator disk model (ADM-BE) for a yawed wind turbine. ...

EPFL2023

Low ozone dry deposition rates to sea ice during the MOSAiC field campaign: Implications for the Arctic boundary layer ozone budget

Julia Schmale, Ivo Fabio Beck, Hélène Paule Angot

Dry deposition to the surface is one of the main removal pathways of tropospheric ozone (O3). We quantified for the first time the impact of O3 deposition to the Arctic sea ice on the planetary boundary layer (PBL) O3 concentration and budget using year-ro ...

2023

Assessing the simulation of snowfall at Dumont d'Urville, Antarctica, during the YOPP-SH special observing campaign

Alexis Berne, Etienne Gabriel Henri Vignon

The performance of a set of atmospheric models and meteorological reanalyses in the representation of precipitation days in Antarctica is assessed using ground-based observations such as a precipitation gauge and a Micro Rain Radar during the Year Of Polar ...

WILEY2023

Present and Future of Rainfall in Antarctica

Alexis Berne, Etienne Gabriel Henri Vignon

While most precipitation in Antarctica falls as snow, little is known about liquid precipitation, although it can have ecological and climatic impacts. This study combines meteorological reports at 10 stations with the ERA5 reanalysis to provide a climatol ...

AMER GEOPHYSICAL UNION2021

Meteorology and snow transport at S17 near Syowa, Antarctica, in austral summer 2018/2019

Varun Sharma, Michael Lehning, Wolf Hendrik Huwald, Jérôme François Sylvain Dujardin, Daniela Brito Melo, Armin Sigmund, Francesco Comola

This dataset contains measurement and simulation data. The measurements characterize the standard meteorology, turbulence, and snow transport at the S17 site near Syowa Station in East Antarctica during an expedition in austral summer 2018/2019. Large-eddy ...

2021

Similarity conditions and cube model tests of snow drift and precipitation preferential deposition patterns

Michael Lehning, Borui Zhang, Qingwen Zhang

We explore the process of modeling aeolian snow transport around buildings by proposing a set of similarity requirements on simulating a single snow fall event with drifting. The similarity criteria are used to guide our wind tunnel tests from the particle ...

ELSEVIER2021

Augmenting the performance of impoverished sensor networks using machine learning and time reversal: Application to lightning nowcasting and location

Amirhossein Mostajabi

Lightning is formed in the atmosphere through the combination of intricate dynamic and microphysical processes. Mainly due to this complexity, attempts to solve the important problem of lightning prediction have generally failed to yield accurate results. ...

EPFL2021

Breaking of Internal Waves and Turbulent Dissipation in an Anticyclonic Mode Water Eddy

Bieito Fernandez Castro

A four-month glider mission was analyzed to assess turbulent dissipation in an anticyclonic eddy at the western boundary of the subtropical North Atlantic. The eddy (radius ≈ 60 km) had a core of low potential vorticity between 100–450 m, with maximum radi ...

2020

Evaluation of CloudSat snowfall rate profiles by a comparison with in situ micro-rain radar observations in East Antarctica

Alexis Berne

The Antarctic continent is a vast desert and is the coldest and the most unknown area on Earth. It contains the Antarctic ice sheet, the largest continental water reservoir on Earth that could be affected by the current global warming, leading to sea level ...

Copernicus GmbH2019

The vertical structure of precipitation at two stations in East Antarctica derived from micro rain radars

Alexis Berne, Jacopo Grazioli

Precipitation over Antarctica is the main term in the surface mass balance of the Antarctic ice sheet, which is crucial for the future evolution of the sea level worldwide. Precipitation, however, remains poorly documented and understood mainly because of ...

Copernicus GmbH2019

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

Short-Term Forecasting of Wake-Induced Fluctuations in Offshore Wind Farms

Arslan Salim Dar

The increasing share of offshore wind energy traded at the spot market requires short term wind direction forecasts to determine wake losses and increased power fluctuations due to multiple wakes in certain wind directions. The information on potential pow ...

2019

A Study of a Large Bipolar Lightning Event Observed at the Säntis Tower

Farhad Rachidi-Haeri, Marcos Rubinstein, Mohammad Azadifar, Wolfgang Schulz, Davide Pavanello

An unusual negative lightning flash was recorded at the Säntis Tower on June 15, 2012. The flash did not contain an initial continuous current typical of upward negative lightning, which is the most common type of event at the Säntis Tower. The flash conta ...

2019

Measurements of precipitation in Dumont d'Urville, Adelie Land, East Antarctica

Alexis Berne, Jacopo Grazioli

The first results of a campaign of intensive observation of precipitation in Dumont d'Urville, Antarctica, are presented. Several instruments collected data from November 2015 to February 2016 or longer, including a polarimetric radar (MXPol), a Micro Rain ...

Copernicus GmbH2017

A radar-based regional extreme rainfall analysis to derive the thresholds for a novel automatic alert system in Switzerland

Alexis Berne, Luca Panziera, Marco Gabella, Urs Martin Germann

This paper presents a regional extreme rainfall analysis based on 10 years of radar data for the 159 regions adopted for official natural hazard warnings in Switzerland. Moreover, a nowcasting tool aimed at issuing heavy precipitation regional alerts is in ...

Copernicus GmbH2016