EESS talk on "Snowfall during the Pyeong Chang 2018 Winter Olympics: summary of a field campaign and case study of an intense precipitation event"

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Event details

Date and time 13.10.2020 12:1513:00  
Place and room
ZOOM
Speaker Josué Gehring, doctoral assistant, Environmental Remote Sensing Laboratory (LTE), IIE; ENAC, EPFL
Category Conferences - Seminars
Abstract:
Snowfall is an important part of the hydrological cycle, the climate in polar and mountainous regions and winter sports. In the mid-latitudes, intense snowfall is mainly associated with the warm or cold front of extratropical cyclones. Forecasting such snowfall events requires a good understanding of the meteorological processes at play and is crucial for wintertime outdoor events, such as Olympic Winter Games.

In this seminar, I will first present a field campaign which took place to support the PyeongChang2018 Olympic and Paralympic Winter Games in South-Korea. The Remote Sensing Laboratory of EPFL provided weather radars and ground-based measurements of clouds and precipitation. The winter of 2018 was very dry in the PyeongChang region and Olympics events were largely held on artificial snow. However, on the 28th of February 2018 an intense warm front associated with an extratropical cyclone led to about 50 cm of snow within 24 hours. In the second part of the seminar, we will analyse how large-scale meteorological conditions influenced the local enhancement of snowfall during this intense precipitation event. We will see that a rising airstream in the warm sector of the cyclone influenced the evolution of snowfall. In particular, turbulence enhanced the aggregation of snowflakes, while supercooled liquid water produced in the rising airstream led to intense riming. These processes were key in the production of intense snowfall, highlighting the importance of interactions between large and local scale processes for accurate snowfall forecasts.

Short biography:
Josué Gehring is a PhD student in the Environmental Remote Sensing Laboratory of EPFL. He is studying the dynamics and microphysics of snowfall from radar and ground based measurements collected in South-Korea and Antarctica. After he completed a BSc. in Environmental Sciences and Engineering at EPFL, he graduated in Atmospheric and Climate Science at ETH in Zurich. While finishing his PhD, he currently works part-time as a forecaster at MeteoSwiss.
 

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Practical information

  • General public
  • Free
  • This event is internal

Organizer

  • EESS - IIE

Contact

Tags

meteorology snowfall weather radars field campaign Winter Olympics South-Korea

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