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SUMMARY:EESS talk on "Persistent Wintertime Cold-Air Pools and Particulate
  Air Pollution in Topographic Basins of Northern Utah"
DTSTART:20181002T121500
DTEND:20181002T131500
DTSTAMP:20260406T112107Z
UID:cb26e81011f8e13b8047c54d4d3a3a509404998135685fbbced42404
CATEGORIES:Conferences - Seminars
DESCRIPTION:Dr Sebastian Hoch\, Research Assistant Professor in Atmospheri
 c Sciences\, University of Utah\, USA - visiting professor Dr Sebastian Ho
 ch is a Research Assistant Professor at the University of Utah. He receive
 d his PhD at ETH Zurich in 2006. His research focuses on boundary layer pr
 ocesses in complex terrain. His interests start with differences in the ra
 diation and surface energy balance and their resulting effects on boundary
  layer evolution\, and range to the flows driven by these contrasts\, and 
 their complex interactions with terrain. His observational studies have co
 vered topographic basins such as Arizona's Meteor Crater (METCRAX 2006\, M
 ETCRAX-II)\, Utah's Bingham Canyon Mine Experiment\, and the Salt Lake Val
 ley (PCAPS\, UWFPS)\, mountainous terrain in the Swiss Alps (DISCHMEX) and
  Utah's West Desert (MATERHORN)\, and addressed processes ranging from dow
 nslope windstorm type flows (METCRAX-II) to fog formation (MATERHORN-FOG\,
  CFOG). Sebastian Hoch has special interest in wind lidar observations\, c
 lear-air radiative cooling\, and the complex interaction between wintertim
 e cold pool meteorology and air chemistry.\nAbstract:\nPersistent winterti
 me temperature inversions in mountainous areas around the world are a key 
 factor leading to cold-season air pollution episodes\, periods of freezing
  rain and drizzle\, fog and haze\, extreme temperature minima\, and transp
 ortation and other weather-related societal problems. For example\, under 
 high pressure conditions during winter\, strong persistent cold-air pools 
 (PCAPs) frequently develop in the Salt Lake\, Cache\, and Utah Valleys in 
 northern Utah\, trapping and accumulating pollutants such as PM2.5 that ha
 ve well-documented adverse health effects.\nSeveral meteorological and air
  chemistry studies have been conducted in the past years and have highligh
 ted the complex interaction between meteorological and chemical processes.
  This presentations will summarize the results of these past observations 
 and the unique processes taking place in the Salt Lake Valley. Observation
 al data include chemical measurements of particulate matter and chemical p
 recursor gases\, highlighting possible reactive pathways from stationary a
 nd mobile platforms. Besides surface based weather stations\, meteorologic
 al data sets include the twice-daily radiosondes from the Salt Lake airpor
 t\, pseudo-vertical temperature soundings based on inexpensive temperature
  data loggers placed along the basin sidewalls\, aerosol backscatter from 
 ceilometers\, sodar\, and wind lidar observations.\nThe typical life cycle
  of a PCAP will be discussed\, including the role of synoptic-scale warm a
 nd cold air advection\, thermally driven flows within and along the edges 
 of the PCAP\, diurnal variation of the vertical PCAP structure\, the forma
 tion of a cloud layer at the cold pool top\, and the role of strong pre-fr
 ontal winds in the removal of the cold pool. Besides the meteorological pr
 ocesses\, their effects on the chemical evolution of a PCAP and on the spa
 tial and temporal variation of PM2.5 concentrations will be addressed.
LOCATION:GR A3 32 https://plan.epfl.ch/?room==GR%20A3%2032
STATUS:CONFIRMED
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