Modeling Climate Change in the Laboratory

Transcription

1 Modeling Climate Change in the Laboratory Miklós Vincze MTA-ELTE Theoretical Physics Research Group ELTE Institute of Physics, von Kármán Laboratory for Enviromental Flows (HU), BTU Cottbus-Senftenberg, Department of Aerodynamics and Fluid Mechanics (DE) Intl. Conf. On Teaching Physics Innovatively Budapest, Hungary August, 2015

2 First of all: What kind of laboratory? A Laboratory for environmental flows (aka geophysical fluid dynamics), called Kármán Laboratory of Eötvös University (hidden abbreviation: K.ár.mán. can also stand for Environmental Flow maniacs(?) in Hungarian) Founded in 1998 by Imre M. Jánosi, Tamás Tél, Gábor K. Szabó, and Viktor Horváth The principle of hydrodynamical similarity enables modeling large-scale (atmosphere, ocean) flow structures Demonstration, teaching (incl. High school groups, Researchers Night, etc.), research Website ( almost up-to-date Video (courtesy index.hu)

3 First of all: What kind of laboratory? A Laboratory for environmental flows (aka geophysical fluid dynamics), called Kármán Laboratory of Eötvös University (hidden abbreviation: K.ár.mán. can also stand for Environmental Flow maniacs(?) in Hungarian) Founded in 2002 by Imre M. Jánosi, Tamás Tél, Gábor K. Szabó, and Viktor Horváth The principle of hydrodynamical similarity enables modeling largescale (atmosphere, ocean) flow structures Website ( almost up-to-date Demonstration, teaching (incl. High school groups, Researchers Night, etc.), research

4 First of all: What kind of laboratory? A Laboratory for environmental flows (aka geophysical fluid dynamics), called Kármán Laboratory of Eötvös University (hidden abbreviation: K.ár.mán. can also stand for Environmental Flow maniacs(?) in Hungarian) Founded in 1998 by Imre M. Jánosi, Tamás Tél, Gábor K. Szabó, and Viktor Horváth The principle of hydrodynamical similarity enables modeling large-scale (atmosphere, ocean) flow structures Demonstration, teaching (incl. High school groups, Researchers Night, etc.), research Website ( almost up-to-date Video (courtesy index.hu) LINK: [from 02:00 to 04:00]

5 Hot topics A Laboratory for environmental flows (aka geophysical fluid dynamics), called Kármán Laboratory of Eötvös University (hidden abbreviation: K.ár.mán. can also stand for Environmental Flow maniacs(?) in Hungarian) Founded in 2002 by Imre M. Jánosi, Tamás Tél, Gábor K. Szabó, and Viktor Horváth The principle of hydrodynamical similarity enables modeling large-scale (atmosphere, ocean) flow structures Demonstration, teaching (incl. High school groups, Researchers Night, etc.), research Website ( almost up-to-date Video (courtesy: index.hu)

6 Hot topics A Laboratory for environmental flows (aka geophysical fluid dynamics), called Kármán Laboratory of Eötvös University (hidden abbreviation: K.ár.mán. can also stand for Environmental Flow maniacs(?) in Hungarian) Founded in 2002 by Imre M. Jánosi, Tamás Tél, Gábor K. Szabó, and Viktor Horváth The principle of hydrodynamical similarity enables modeling large-scale (atmosphere, ocean) flow structures Demonstration, teaching (incl. High school groups, Researchers Night, etc.), research Website ( almost up-to-date Video (courtesy: index.hu)

7 Hot topics A Laboratory for environmental flows (aka geophysical fluid dynamics), called Kármán Laboratory of Eötvös University (hidden abbreviation: K.ár.mán. can also stand for Environmental Flow maniacs(?) in Hungarian) Founded in 2002 by Imre M. Jánosi, Tamás Tél, Gábor K. Szabó, and Viktor Horváth The principle of hydrodynamical similarity enables modeling large-scale (atmosphere, ocean) flow structures Demonstration, teaching (incl. High school groups, Researchers Night, etc.), research Website ( almost up-to-date Video (courtesy: index.hu)

8 Hot topics A Laboratory for environmental flows (aka geophysical fluid dynamics), called Kármán Laboratory of Eötvös University (hidden abbreviation: K.ár.mán. can also stand for Environmental Flow maniacs(?) in Hungarian) Founded in 2002 by Imre M. Jánosi, Tamás Tél, Gábor K. Szabó, and Viktor Horváth The principle of hydrodynamical similarity enables modeling large-scale (atmosphere, ocean) flow structures Demonstration, teaching (incl. High school groups, Researchers Night, etc.), research Website ( almost up-to-date Video (courtesy: index.hu)

9 Why to use such a lab for research purposes nowadays? - #1: Lab experiments as analog computers It always bothers me that, according to the laws as we understand them today, it takes a computing machine an infinite number of logical operations to figure out what goes on in no matter how tiny a region of space, and no matter how tiny a region of time. - R. P. Feynman (In: The Character of Physical Law, 1967)

10 Why to use such a lab for research purposes nowadays? - #2: Test-bed for Nimitz class complex flow models A somewhat provocative statement: The operational numerical methods and models for weather forasting and climate prediction can be validated only in the lab! (if at all)

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28 So, what can be done? How to separate parametrization (discretization, etc.) errors from those that originate from our incomplete understanding of the system Let s build/find a physical system which behaves like the atmosphere, but still much simpler, and all the governing equations are correctly understood!

29 A minimal model of mid-latitude weather - A large variety of the typical atmospheric phenomena of the midlatitudes are primarily driven by two factors only. - Rotation + meridional temperature difference weather - Let s use a differentially heated rotating circular tank for method validation!

30 A minimal model of mid-latitude weather A differentially heated cylindrical tank, mounted on a turntable. Rotating annulus Geometrical parameters (Cottbus): a = 45 mm b = 120 mm d = 135 mm

31 A minimal model of mid-latitude weather A differentially heated cylindrical tank, mounted on a turntable. Rotating annulus Geometrical parameters (Cottbus): a = 45 mm b = 120 mm d = 135 mm

32 A minimal model of mid-latitude weather A differentially heated cylindrical tank, mounted on a turntable. Rotating annulus Geometrical parameters (Budapest): a = 45 mm b = 150 mm d = 40 mm

33 Basics: baroclinic instability

34 Basics: baroclinic instability Sideways convection no threshold in ΔT (i.e. No critical Rayleigh number ) Any temperature difference can initiate the flow

35 Basics: baroclinic instability Sideways convection no threshold in ΔT (i.e. No critical Rayleigh number ) Any temperature difference can initiate the flow

36 Basics: baroclinic instability

37 Rotation! Basics: baroclinic instability

38 Baroclinic instability Rotation! Zonal flow (thermal wind) Geostrophic theory: Tilted density surfaces

39 Baroclinic instability Rotation! Zonal flow (thermal wind) Geostrophic theory: Tilted density surfaces

40 Baroclinic instability Baroclinic instability! Rotation! Zonal flow (thermal wind) Geostrophic theory: Tilted density surfaces

41 Baroclinic waves - control parameters: rotation rate, radial temperature difference - Different planetary atmospheres can be modelled Venus: slow rotation, zonal flow Earth: fast rotation Coriolis effect cyclones ( weather )

42 Baroclinic waves, planetary analogies - control parameters: rotation rate, radial temperature difference - Different planetary atmospheres can be modelled Venus: slow rotation, zonal flow Earth: fast rotation Coriolis effect cyclones ( weather )

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46 The regime diagram (after Fultz)

47 The regime diagram (after Fultz)

48 The regime diagram (after Fultz)

49 The regime diagram (after Fultz)

50 Preliminary results

51 Preliminary results

52 Comments, conclusions: In the model decreasing equator-to-pole temperature difference seems to yield smaller fluctuations (in terms of magnitude) Temporal behaviour needs to be investigated! (Expectation: smaller temperature difference makes the model weather less predictable smaller velocities, smaller cyclones, more freedom for the structures to interact) Significant differences between the three runs! In many cases the trends are not even evident in the temperature anomaly records! A much-much larger ensemble is needed. (Work in progress.) Climate is what you expect, weather is what you get.

53 Thank you for your attention!