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Jets and Annular Structures in Geophysical Fluids: Introduction

Jets and Annular Structures in Geophysical Fluids: Introduction. Shigeo YODEN Kyoto Univ. This Chapman conference. Objectives To bring together those working on the problem of annular modes with those working on related features and dynamics within other geophysical fluids

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Jets and Annular Structures in Geophysical Fluids: Introduction

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  1. Jets and Annular Structures in Geophysical Fluids: Introduction Shigeo YODEN Kyoto Univ.

  2. This Chapman conference • Objectives • To bring together those working on the problem of annular modes with those working on related features and dynamics within other geophysical fluids • To promote the development of predictive theories of annular modes and the behaviors of jets in Earth's atmosphere, in the oceans, and in planetary atmospheres • Topics (A) Jets in the Atmosphere (B) Jets in the Oceans (C) Atmospheric Annular Modes (D) Jets and Annular Flows in Planetary Atmospheres (E) Jets in Idealized Flows (GFD)

  3. 1980 1981 double-jet regime single-jet regime 1982 1983 My very private motivations (A, C) Atmospheric Jets and Annular Modes • Yoden, Shiotani, and Hirota (1987) Multiple planetary flow regimes in the southern hemisphere. J.Met.Soc.Japan, 65-4, 571-586. • analysis of low-frequency variations of zonal mean zonal wind • single-jet regime  double-jet regime “SH Annular Modes” (c.f., Thompson and Wallace, 2000)

  4. Thompson and Wallace (2000) Annular modes in the extratropical circulation. Part I: Month-to-month variability. J. Climate, 13, 1000-1016. Southern Hemisphere Northern Hemisphere

  5. Akahori and Yoden (1997) Zonal flow vacillation and bimodality of baroclinic eddy life cycles in a simple global circulation model. J.Atmos.Sci., 54-19, 2349-2361. • perpetual runs of an idealized Mechanistic Circulation Model (c.f., Thorncroft et al., 1993) “LC1” anticyclonic breaking in high-latitude jet regime “LC2” cyclonic breaking in low-latitude jet regime

  6. LC1-type life cycle the mean jet anticyclonic breaking LC2-type life cycle the mean jet cyclonic breaking • Thorncroft, Hoskins, and McIntyre, 1993: Two paradigms of baroclinic wave life-cycle behaviour. Quart.J.Roy.Met.Soc., 119, 17-56. • PV contour on an isentropic surface (PV- plot) in an Atlantic storm track sharing its main characteristics

  7. Robinson, 2006: Eddy mediated interactions between low latitudes and the extratropics. The Global Circulation of the Atmosphere (Schneider and Sobel Eds.), Princeton Univ. Press. • Schematics of eddy-zonal flow interactions in a “normal” circulation • effects of tropical warming (ElNino) • effects of global greenhouse warming • regime shift to “equatorial super rotation” ?

  8. Yoden, Yamaga, Pawson, and Langematz (1999) J.Met.Soc.Japan, 77-2, 431-445. • Yoden, Taguchi, and Naito (2002) Numerical studies on time variations of the troposphere- stratosphere coupled system. J.Met.Soc.Japan, 80-4B, 811- 830. • composite analysis of normalized zonal-mean temperature variations for • 34 zonal wave-1 SSW events • 30 zonal wave-2 SSW events • difference in downward penetration to the troposphere WN1 events WN2 events

  9. Baldwin and Dunkerton (1999) J.Geophys.Res., 104, 30,937-30,946. • ------ and ------ (2001) Stratospheric harbingers of anomalous weather regimes. Science, 244, 581-584.

  10. dynamical interactions • baroclinic wave (BW) - zonal flow interaction • rotating annulus experiments (c.f., tilted-trough vacillation) • Southern-Hemisphere like situation • role of forced planetary waves (PWs) • Northern-Hemisphere like situation • troposphere-stratosphere coupling • vertically propagating PWs and evanescent BWs • time-dependent behavior • oscillations • vacillation (Lorenz, 1963) • regimes • multiple flow equilibria(Charney and DeVore, 1979) • predictability/prediction • time-scale separation: intraseasonal time-scale from that of BWs • hemispheric vs. local: blocking phenomena, Rossby wave trains, ... • circulation changes due to global warming

  11. time-averaged circulation forced by periodic wave forcing periodic domain closed basin Galperin et al. (2004, GRL) (B) Jets in the Ocean • Rhines (1994) Jets. Chaos, 4-2, 313-339. • periodic domain  closed basin • Antarctic circumpolar current • multiple jets in a closed basin • high-resolution model • wave transport vs. turbulent mixing • ......

  12. Sun (D) Jets and Annular Flows in Planetary Atmospheres • Dowling and Spiegel (1990) Stellar and Jovian vortices. Ann. N.Y. Ac. Sci., 617, 190-216 • Observed “surface” wind profiles • deep convection in spherical shell or shallow 2D turbulence • universality and diversity of planetary atmospheres • .......

  13. (E)Jets in Idealized Flows (GFD) • Ishioka, Hasegawa and Yoden (2006) Asymmetrization of jet profiles in beta-plane turbulence • Rhines (1975, JFM ) “Waves and turbulence on a beta-plane” • characteristic wavenumber

  14. (c.f., Ishioka et al., 1999) Ω=400 • emergence of a westward circumpolar vortex • zonal jet structure in low-latitudes • Yoden and Yamada (1993) A numerical experiment on two-dimensional decaying turbulence on a rotating sphere. J.Atmos.Sci., 50-4, 631-643. • Williams (1978) “Barotropic representation of Jovian and Terrestrial Turbulence. (Williams, 1978)

  15. Laboratory experiments on “Rossby waves and the polar vortex” • Geophysical Fluid Dynamics Laboratory, University of Washington • a polar ß-plane experiment: rapidly rotating (Ω=3.2/s) homogeneous fluid with a free surface • http://www.ocean.washington.edu/ • research/gfd/gfd.html • producing mechanism of a westward circumpolar vortex • weakly nonlinear Rossby waves or highly nonlinear PV mixing • 2D non-divergent barotropic fluid vs. shallow water • infinite or finite value of Rossby’s deformation radius • balanced dynamics, role of gravity waves • application to the real atmospheres and oceans

  16. This Chapman conference • Objectives • To bring together those working on the problem of annular modes with those working on related features and dynamics within other geophysical fluids • To promote the development of predictive theories of annular modes and the behaviors of jets in Earth‘s atmosphere, in the oceans, and in planetary atmospheres, or, in Geophysical Fluids • Topics (A) Jets in the Atmosphere (B) Jets in the Oceans (C) Atmospheric Annular Modes (D) Jets and Annular Flows in Planetary Atmospheres (E) Jets in Idealized Flows (GFD)

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