geophysical fluid dynamics:...
TRANSCRIPT
![Page 1: Geophysical Fluid Dynamics: Introductiongershwin.ens.fr/zeitlin/lectures/cours_ENS/Introduction.pdfGeophysical Fluid Dynamics: Introduction V. Zeitlin M1 ENS Global view Dynamical](https://reader036.vdocuments.us/reader036/viewer/2022071409/610195c8a9e0e40b33182e82/html5/thumbnails/1.jpg)
Global view
Dynamical actors:jets, vortices andwavesAtmospheric and oceanicjets
Atmospheric and oceanicvortices
Atmospheric and oceanicinertia-gravity waves
Equatorial waves
What is next?
Geophysical Fluid Dynamics:Introduction
V. Zeitlin
M1 ENS
![Page 2: Geophysical Fluid Dynamics: Introductiongershwin.ens.fr/zeitlin/lectures/cours_ENS/Introduction.pdfGeophysical Fluid Dynamics: Introduction V. Zeitlin M1 ENS Global view Dynamical](https://reader036.vdocuments.us/reader036/viewer/2022071409/610195c8a9e0e40b33182e82/html5/thumbnails/2.jpg)
Global view
Dynamical actors:jets, vortices andwavesAtmospheric and oceanicjets
Atmospheric and oceanicvortices
Atmospheric and oceanicinertia-gravity waves
Equatorial waves
What is next?
Atmosphere: space-view
Courtesy: NASA
Visible in clouds - (unperfect) tracers : extratropicaldepressions, equatorial easterly waves and emergingtropical storm, inertia-gravity wavesOcean: similar, but not visible without tracers.
![Page 3: Geophysical Fluid Dynamics: Introductiongershwin.ens.fr/zeitlin/lectures/cours_ENS/Introduction.pdfGeophysical Fluid Dynamics: Introduction V. Zeitlin M1 ENS Global view Dynamical](https://reader036.vdocuments.us/reader036/viewer/2022071409/610195c8a9e0e40b33182e82/html5/thumbnails/3.jpg)
Global view
Dynamical actors:jets, vortices andwavesAtmospheric and oceanicjets
Atmospheric and oceanicvortices
Atmospheric and oceanicinertia-gravity waves
Equatorial waves
What is next?
General observations
Atmosphere and ocean: fluid-dynamics systemsI on the rotating (∼) sphereI with stratification due to gravityI with non-trivial bottom (atmosphere, ocean) and
lateral (ocean) boundariesI with multiple phases and phase transitions (water
vapor, liquid water, ice)
![Page 4: Geophysical Fluid Dynamics: Introductiongershwin.ens.fr/zeitlin/lectures/cours_ENS/Introduction.pdfGeophysical Fluid Dynamics: Introduction V. Zeitlin M1 ENS Global view Dynamical](https://reader036.vdocuments.us/reader036/viewer/2022071409/610195c8a9e0e40b33182e82/html5/thumbnails/4.jpg)
Global view
Dynamical actors:jets, vortices andwavesAtmospheric and oceanicjets
Atmospheric and oceanicvortices
Atmospheric and oceanicinertia-gravity waves
Equatorial waves
What is next?
Typical scales
Atmosphere:
I Planetary (general circulation O(10000 km)
I Synoptic (weather systems) O(1000 km)
I Meso-scale (thunderstorms) O(10 km)
I Micro-scale (weather at the airport) O(10− 100 m)
Ocean:I Planetary (general circulation O(1000− 10000 km)
I Meso-scale (Gulf-stream rings) O(100 km)
I Sub-Mesoscale (coastal phenomena) O(1− 10 km)
I Small-scale (swell ) O(10− 100 m)
![Page 5: Geophysical Fluid Dynamics: Introductiongershwin.ens.fr/zeitlin/lectures/cours_ENS/Introduction.pdfGeophysical Fluid Dynamics: Introduction V. Zeitlin M1 ENS Global view Dynamical](https://reader036.vdocuments.us/reader036/viewer/2022071409/610195c8a9e0e40b33182e82/html5/thumbnails/5.jpg)
Global view
Dynamical actors:jets, vortices andwavesAtmospheric and oceanicjets
Atmospheric and oceanicvortices
Atmospheric and oceanicinertia-gravity waves
Equatorial waves
What is next?
Upper tropospheric jet
Courtesy: COLA/NOAA
Mid-latitude jet-stream in the Northern Hemisphere asfollows from the analysis in a general circulation model.Streamlines and modulus of velocity (colors).
![Page 6: Geophysical Fluid Dynamics: Introductiongershwin.ens.fr/zeitlin/lectures/cours_ENS/Introduction.pdfGeophysical Fluid Dynamics: Introduction V. Zeitlin M1 ENS Global view Dynamical](https://reader036.vdocuments.us/reader036/viewer/2022071409/610195c8a9e0e40b33182e82/html5/thumbnails/6.jpg)
Global view
Dynamical actors:jets, vortices andwavesAtmospheric and oceanicjets
Atmospheric and oceanicvortices
Atmospheric and oceanicinertia-gravity waves
Equatorial waves
What is next?
Gulf-stream
Courtesy: US Navy
Gulf-stream as seen in the sea-surface height anomaly(colors) observed by satellite. See geostrophic balance inthe main course for the relation between height andvelocity.
![Page 7: Geophysical Fluid Dynamics: Introductiongershwin.ens.fr/zeitlin/lectures/cours_ENS/Introduction.pdfGeophysical Fluid Dynamics: Introduction V. Zeitlin M1 ENS Global view Dynamical](https://reader036.vdocuments.us/reader036/viewer/2022071409/610195c8a9e0e40b33182e82/html5/thumbnails/7.jpg)
Global view
Dynamical actors:jets, vortices andwavesAtmospheric and oceanicjets
Atmospheric and oceanicvortices
Atmospheric and oceanicinertia-gravity waves
Equatorial waves
What is next?
Jets on other planets
Courtesy: NASA
Alternating jet-streams in Jovial atmosphere as seen byJuno mission. As in previous images, eddies areproduced by instabilities of the jets.
![Page 8: Geophysical Fluid Dynamics: Introductiongershwin.ens.fr/zeitlin/lectures/cours_ENS/Introduction.pdfGeophysical Fluid Dynamics: Introduction V. Zeitlin M1 ENS Global view Dynamical](https://reader036.vdocuments.us/reader036/viewer/2022071409/610195c8a9e0e40b33182e82/html5/thumbnails/8.jpg)
Global view
Dynamical actors:jets, vortices andwavesAtmospheric and oceanicjets
Atmospheric and oceanicvortices
Atmospheric and oceanicinertia-gravity waves
Equatorial waves
What is next?
Tropospheric vortices in data
Courtesy: COLA/NOAA
Tropospheric eddies in the Northern Hemisphere asfollows from the analysis in a general circulation model at500 mb ≈ 4.5 km altitude. Colors: relative vorticity (curl ofthe horizontal velocity). Red : cyclones, Blue:anticyclones.
![Page 9: Geophysical Fluid Dynamics: Introductiongershwin.ens.fr/zeitlin/lectures/cours_ENS/Introduction.pdfGeophysical Fluid Dynamics: Introduction V. Zeitlin M1 ENS Global view Dynamical](https://reader036.vdocuments.us/reader036/viewer/2022071409/610195c8a9e0e40b33182e82/html5/thumbnails/9.jpg)
Global view
Dynamical actors:jets, vortices andwavesAtmospheric and oceanicjets
Atmospheric and oceanicvortices
Atmospheric and oceanicinertia-gravity waves
Equatorial waves
What is next?
Tropospheric vortices in satellite images
Courtesy: NASA
Double cyclone in the Northern hemisphere.
![Page 10: Geophysical Fluid Dynamics: Introductiongershwin.ens.fr/zeitlin/lectures/cours_ENS/Introduction.pdfGeophysical Fluid Dynamics: Introduction V. Zeitlin M1 ENS Global view Dynamical](https://reader036.vdocuments.us/reader036/viewer/2022071409/610195c8a9e0e40b33182e82/html5/thumbnails/10.jpg)
Global view
Dynamical actors:jets, vortices andwavesAtmospheric and oceanicjets
Atmospheric and oceanicvortices
Atmospheric and oceanicinertia-gravity waves
Equatorial waves
What is next?
Tropical cyclones
Courtesy: NOAA
Tropical cyclone - intense sub-synoptic scale troposphericvortex.
![Page 11: Geophysical Fluid Dynamics: Introductiongershwin.ens.fr/zeitlin/lectures/cours_ENS/Introduction.pdfGeophysical Fluid Dynamics: Introduction V. Zeitlin M1 ENS Global view Dynamical](https://reader036.vdocuments.us/reader036/viewer/2022071409/610195c8a9e0e40b33182e82/html5/thumbnails/11.jpg)
Global view
Dynamical actors:jets, vortices andwavesAtmospheric and oceanicjets
Atmospheric and oceanicvortices
Atmospheric and oceanicinertia-gravity waves
Equatorial waves
What is next?
Gulf-stream rings
Courtesy: US Navy
Gulf-stream vortices as seen in the sea-surface heightanomaly deviation (colors) observed by satellite. Seegeostrophic balance in the main course for the relationbetween height and velocity.
![Page 12: Geophysical Fluid Dynamics: Introductiongershwin.ens.fr/zeitlin/lectures/cours_ENS/Introduction.pdfGeophysical Fluid Dynamics: Introduction V. Zeitlin M1 ENS Global view Dynamical](https://reader036.vdocuments.us/reader036/viewer/2022071409/610195c8a9e0e40b33182e82/html5/thumbnails/12.jpg)
Global view
Dynamical actors:jets, vortices andwavesAtmospheric and oceanicjets
Atmospheric and oceanicvortices
Atmospheric and oceanicinertia-gravity waves
Equatorial waves
What is next?
Vortices in Arabian see
Courtesy: US Navy
Vortices in Arabian see as seen in the plankton bloom(false colors).
![Page 13: Geophysical Fluid Dynamics: Introductiongershwin.ens.fr/zeitlin/lectures/cours_ENS/Introduction.pdfGeophysical Fluid Dynamics: Introduction V. Zeitlin M1 ENS Global view Dynamical](https://reader036.vdocuments.us/reader036/viewer/2022071409/610195c8a9e0e40b33182e82/html5/thumbnails/13.jpg)
Global view
Dynamical actors:jets, vortices andwavesAtmospheric and oceanicjets
Atmospheric and oceanicvortices
Atmospheric and oceanicinertia-gravity waves
Equatorial waves
What is next?
Vortices in the the atmospheres of otherplanets
Courtesy: NASA
Great Red Spot in Jovial atmosphere - a quasi-stationaryanticyclonic vortex, as seen by Juno mission.
![Page 14: Geophysical Fluid Dynamics: Introductiongershwin.ens.fr/zeitlin/lectures/cours_ENS/Introduction.pdfGeophysical Fluid Dynamics: Introduction V. Zeitlin M1 ENS Global view Dynamical](https://reader036.vdocuments.us/reader036/viewer/2022071409/610195c8a9e0e40b33182e82/html5/thumbnails/14.jpg)
Global view
Dynamical actors:jets, vortices andwavesAtmospheric and oceanicjets
Atmospheric and oceanicvortices
Atmospheric and oceanicinertia-gravity waves
Equatorial waves
What is next?
Internal inertia-gravity wave in the Andamansea
Courtesy: NOAA
Large-scale internal wave as seen in the satellite image.
![Page 15: Geophysical Fluid Dynamics: Introductiongershwin.ens.fr/zeitlin/lectures/cours_ENS/Introduction.pdfGeophysical Fluid Dynamics: Introduction V. Zeitlin M1 ENS Global view Dynamical](https://reader036.vdocuments.us/reader036/viewer/2022071409/610195c8a9e0e40b33182e82/html5/thumbnails/15.jpg)
Global view
Dynamical actors:jets, vortices andwavesAtmospheric and oceanicjets
Atmospheric and oceanicvortices
Atmospheric and oceanicinertia-gravity waves
Equatorial waves
What is next?
Internal inertia-gravity wave in Mediterranean
Courtesy: NASA
Large-scale internal wave produced by a tide in theGibraltar straight as seen in the satellite image.
![Page 16: Geophysical Fluid Dynamics: Introductiongershwin.ens.fr/zeitlin/lectures/cours_ENS/Introduction.pdfGeophysical Fluid Dynamics: Introduction V. Zeitlin M1 ENS Global view Dynamical](https://reader036.vdocuments.us/reader036/viewer/2022071409/610195c8a9e0e40b33182e82/html5/thumbnails/16.jpg)
Global view
Dynamical actors:jets, vortices andwavesAtmospheric and oceanicjets
Atmospheric and oceanicvortices
Atmospheric and oceanicinertia-gravity waves
Equatorial waves
What is next?
Atmospheric inertia-gravity waves nearAustralian coast
Courtesy: NASA
Traces of inertia-gravity waves in clouds.
![Page 17: Geophysical Fluid Dynamics: Introductiongershwin.ens.fr/zeitlin/lectures/cours_ENS/Introduction.pdfGeophysical Fluid Dynamics: Introduction V. Zeitlin M1 ENS Global view Dynamical](https://reader036.vdocuments.us/reader036/viewer/2022071409/610195c8a9e0e40b33182e82/html5/thumbnails/17.jpg)
Global view
Dynamical actors:jets, vortices andwavesAtmospheric and oceanicjets
Atmospheric and oceanicvortices
Atmospheric and oceanicinertia-gravity waves
Equatorial waves
What is next?
“Morning glory” in Northern Australia
Courtesy: R. Grimshaw
A close view of the internal gravity wave in theatmosphere.
![Page 18: Geophysical Fluid Dynamics: Introductiongershwin.ens.fr/zeitlin/lectures/cours_ENS/Introduction.pdfGeophysical Fluid Dynamics: Introduction V. Zeitlin M1 ENS Global view Dynamical](https://reader036.vdocuments.us/reader036/viewer/2022071409/610195c8a9e0e40b33182e82/html5/thumbnails/18.jpg)
Global view
Dynamical actors:jets, vortices andwavesAtmospheric and oceanicjets
Atmospheric and oceanicvortices
Atmospheric and oceanicinertia-gravity waves
Equatorial waves
What is next?
Atmospheric lee wave behind an island
Courtesy: NOAA
Lee wave as seen in the clouds behind an island.
![Page 19: Geophysical Fluid Dynamics: Introductiongershwin.ens.fr/zeitlin/lectures/cours_ENS/Introduction.pdfGeophysical Fluid Dynamics: Introduction V. Zeitlin M1 ENS Global view Dynamical](https://reader036.vdocuments.us/reader036/viewer/2022071409/610195c8a9e0e40b33182e82/html5/thumbnails/19.jpg)
Global view
Dynamical actors:jets, vortices andwavesAtmospheric and oceanicjets
Atmospheric and oceanicvortices
Atmospheric and oceanicinertia-gravity waves
Equatorial waves
What is next?
Atmospheric equatorial Rossby wave
Courtesy: NOAA
Equatorial Rossby-wave packet in the form of twincyclones seen as cloud clusters at both sides of theEquator.
![Page 20: Geophysical Fluid Dynamics: Introductiongershwin.ens.fr/zeitlin/lectures/cours_ENS/Introduction.pdfGeophysical Fluid Dynamics: Introduction V. Zeitlin M1 ENS Global view Dynamical](https://reader036.vdocuments.us/reader036/viewer/2022071409/610195c8a9e0e40b33182e82/html5/thumbnails/20.jpg)
Global view
Dynamical actors:jets, vortices andwavesAtmospheric and oceanicjets
Atmospheric and oceanicvortices
Atmospheric and oceanicinertia-gravity waves
Equatorial waves
What is next?
Atmospheric equatorial Kelvin wave
Courtesy: NOAA
Equatorial Kelvin-wave packet in the form of cloud arc(red) at the Equator.
![Page 21: Geophysical Fluid Dynamics: Introductiongershwin.ens.fr/zeitlin/lectures/cours_ENS/Introduction.pdfGeophysical Fluid Dynamics: Introduction V. Zeitlin M1 ENS Global view Dynamical](https://reader036.vdocuments.us/reader036/viewer/2022071409/610195c8a9e0e40b33182e82/html5/thumbnails/21.jpg)
Global view
Dynamical actors:jets, vortices andwavesAtmospheric and oceanicjets
Atmospheric and oceanicvortices
Atmospheric and oceanicinertia-gravity waves
Equatorial waves
What is next?
Program:
I Maths refresher - need vector analysis, Fourieranalysis, and PDEs
I Fluid dynamics refresher: GFD is fluid dynamics.I Constructing the master model Primitive
Equations(PE) and understanding its properties.I Building simplified versions of PE: vertically
averaged - shallow-water models, and/ortime-averaged - quasi-geostrophic models.
I Understanding vortex and wave dynamics with themI Acquiring basic notions of jet instabilities