BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Interaction between Planetary Wave and Gravity Waves in the Middle
  Atmosphere - Professor Hye-Yeong Chun\, Department of Atmospheric Science
 s\, Yonsei University
DTSTART:20220421T100000Z
DTEND:20220421T110000Z
UID:TALK168866@talks.cam.ac.uk
CONTACT:Alison Ming
DESCRIPTION:CCfCS curated talk from BAS AIC seminar series\n\nBoth planeta
 ry waves (PWs) and gravity waves (GWs) play important role in atmospheric 
 dynamics. Interaction between PWs and GWs in the middle atmosphere is inve
 stigated in two aspects: (i) In situ generation of PWs forced by non-conse
 rvative GW drag (GWD) forcing term in the linearized quasi-geostrophic pot
 ential vorticity equation\, and (ii) compensation between PW forcing and o
 rographic GWD in the northern winter stratosphere through baroclinic insta
 bility. The first topic is applied to a vortex split-type stratospheric su
 dden warming (SSW) event that occurred in January 2009. The result demonst
 rates that the amplification of the PWs of zonal wavenumber 2 in the strat
 osphere before the onset of 2009 SSW is due to the downward-propagating tr
 ansient PWs of zonal wavenumber 2 that are generated by non-conservative G
 W forcing from above. The second topic is investigated to examine whether 
 the compensation between PW forcing and orographic GWD that revealed from 
 some idealized general circulation model studies appears in the real atmos
 phere using reanalysis data for 32 years in the northern winter. It is fou
 nd that in-situ generation of PWs and the refractive-index modification oc
 cur simultaneously in the compensation processes\, with stronger contribut
 ion by the refractive-index modification for weak orographic GWD cases.\n\
 n \n\nBiography:  Hye-Yeong did her PhD in 1991 at North Carolina State Un
 iversity in USA on critical-level dynamics of atmospheric gravity waves fo
 rced by diabatic forcing both in theoretical and numerical modelling aspec
 ts. She then moved to GSFC/NASA as a postdoc focusing on solitary wave dyn
 amics. After she returned to Korea and joined to Yonsei University as a pr
 ofessor\, she worked on parameterization of convective gravity waves for u
 se in climate models and mesoscale simulation of convective gravity waves.
  Since 2006\, she also has worked on aviation turbulence in the free atmos
 phere. She served as a Dean of the University College of Yonsei University
  and President of Korean Meteorological Society. Her recent research inter
 ests include PW-GW interaction and QBO dynamics\, specifically QBO disrupt
 ions.\n\n 
LOCATION:British Antarctic Survey
END:VEVENT
END:VCALENDAR