BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Random movement of mesoscale eddies in the global ocean - Xiaoming
  Zhai\, University of East Anglia
DTSTART:20191112T110000Z
DTEND:20191112T120000Z
UID:TALK134788@talks.cam.ac.uk
CONTACT:Louis Couston
DESCRIPTION:In this study we track and analyze eddy movement in the global
  ocean using 20 years of altimeter data and show that\, in addition to the
  well-known westward propagation and slight polarity-based meridional defl
 ections\, mesoscale eddies also move randomly in all directions at all lat
 itudes as a result of eddy-eddy interaction. The speed of this random eddy
  movement decreases with latitude and equals the baroclinic Rossby wave sp
 eed at about 25° of latitude. The tracked eddies are on average isotropic
  at mid and high latitudes\, but become noticeably more elongated in the z
 onal direction at low latitudes. Our analyses suggest a critical latitude 
 of approximately 25° that separates the global ocean into a low-latitude 
 anisotropic wavelike regime and a high-latitude isotropic turbulence regim
 e. One important consequence of random eddy movement is that it results in
  lateral diffusion of eddy energy. The associated eddy energy diffusivity\
 , estimated using two different methods\, is found to be a function of lat
 itude. The zonal-mean eddy energy diffusivity varies from over 1500 m2 s-1
  at low latitudes to around 500 m2 s-1 at high latitudes\, but significant
 ly larger values are found in the eddy energy hotspots at all latitudes\, 
 in excess of 5000 m2 s-1. Results from this study have important implicati
 ons for recently-developed energetically-consistent mesoscale eddy paramet
 erization schemes which require solving the eddy energy budget. 
LOCATION:British Antarctic Survey\, Seminar Room 330b
END:VEVENT
END:VCALENDAR