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PRODID:UW-Madison-Physics-Events
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SEQUENCE:1
UID:UW-Physics-Event-8922
DTSTART:20250919T203000Z
DTEND:20250919T230000Z
DTSTAMP:20260407T075906Z
LAST-MODIFIED:20250902T172603Z
LOCATION:Chamberlin 2241
SUMMARY:Waves of Topological Origin in the Fluid Earth System and Beyo
 nd\, Physics Department Colloquium\, Brad Marston\, Brown University
DESCRIPTION:Symmetries and topology are central to our understanding o
 f physical systems. Topology\, for instance\, explains the precise qua
 ntization of the Hall effect and the protection of surface states in t
 opological insulators against scattering from disorder or bumps. Howev
 er discrete symmetries and topology have not\, until recently\, contri
 buted much to our understanding of the fluid dynamics of oceans and at
 mospheres. In this talk I show that\, as a consequence of the rotation
  of the Earth that breaks time reversal symmetry\, equatorial Kelvin a
 nd Yanai waves emerge as topologically protected edge modes. The non-t
 rivial topology of the bulk Poincaré waves is revealed through their 
 winding number in frequency - wavevector space. Bulk-interface corresp
 ondence then guarantees the existence of the two equatorial waves. I d
 iscuss our recent direct detection of the winding number in observatio
 ns of Earth’s stratosphere.
\nThus the oceans and atmosphere of Eart
 h naturally share basic physics with topological
\ninsulators. As equa
 torially trapped Kelvin waves in the Pacific ocean are an important
\n
 component of El Niño Southern Oscillation\, the largest climate oscil
 lation on time scales of a few years\, topology plays a surprising rol
 e in Earth’s climate system. We also predict that waves of topologic
 al origin will arise in magnetized plasmas.  I will describe experimen
 ts that we are conducting at UCLA’s Basic Plasma Science Facility (B
 aPSF).  The waves may also arise in the solar system and beyond.
URL:https://www.physics.wisc.edu/events/?id=8922
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