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Explore the dynamics of tropical atmospheric phenomena from a nondivergent perspective. Analyzing vorticity and divergence patterns in relation to the Madden-Julian Oscillation, this book delves into self-organization and scale analysis in atmospheric dynamics. With observational evidence and theoretical analyses, it questions the balance between divergence and vorticity in large-scale tropical systems. Discover the implications of asymptotic nondivergence for understanding convective organization and criticality in tropical atmospheres. This comprehensive work sheds light on the complexities of atmospheric dynamics in tropical regions.
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Large-Scale Tropical Atmospheric Dynamics: Asymptotic Nondivergence & Self-Organization (& Self-Organization) by Jun-Ichi Yano With Sandrine Mulet, Marine Bonazzola, Kevin Delayen, S. Hagos, C. Zhang, Changhai Liu, M. Moncrieff
Large-Scale Tropical Atmospheric Dynamics: Strongly Divergent ? or Asymptotically Nondivergent ?
Madden-Julian Oscillation (MJO) :Madden & Julian (1972) 30-60 days Dominantly Divergent-Flow Circulations ?
MJO is Vorticity Dominant? (e.g., Yanai et al., 2000)
Balanced? (Free-Ride, Fraedrich & McBride 1989): (TOGA-COARE IFA Observation) moisture Heat Budget Condensation(K/day) Convective Heating(K/day) Vertical Advection+Radiation Vertical Advection Vertical Advection =Diabatic Heating
Scale Analysis (Charney 1963) Thermodynamic equaton: i.e., the vertical velocity vanishes to leading order i.e., the horizontal divergence vanishes to leading order of asymptotic expansion i.e., Asymptotic Nondivergence
Observatinoal Evidences? TOGA-COARE LSA data set (Yano, Mulet, Bonazzola 2009, Tellus)
Temporal Evolution of Longitude-Height Section: Divergence vorticity
850hPa Scatter Plots between Vorticity and Divergence divergence vorticity 500hPa divergence vorticity 250hPa divergence vorticity
Cumulative Probability for |divergence/vorticity| : i.e., at majority of points: Divergence < Vorticity
Quantification: Measure of a Variability (RMS of a Moving Average): where
Asymptotic Tendency for Non-Divergence: Divergence/Vorticity(Total) horizontal scale (km) Time scale (days)
Asymptotic Tendency for Non-Divergence: Divergence/Vorticity(Transient) horizontal scale (km) Time scale (days)
Balanced? (Free-Ride, Fraedrich & McBride 1989): (TOGA-COARE IFA Observation) moisture Heat Budget Condensation(K/day) Convective Heating(K/day) Effectively Neutral Stratification:hE=0 : Vertical Advection+Radiation Vertical Advection 1. Vertical Advection =Diabatic Heating :No Waves (Gravity)!
OLR Spectrum: Dry Equatorial Waves with hE=25 m (Wheeler & Kiladis 1999) Equatorially asymmetric Equatorially symmetric Frequency Frequency Zonal Wavenumber Zonal Wavenumber
Equivalent depth: hE • Vertical Scale of the wave: D • Gravity-Wave Speed: cg=(ghE)1/2~ND
Scale Analysis (Summary):Yano and Bonazzola (2009, JAS) (Simple) (Asymptotic) R.2. Vertical Advection: • L~3000km, U~3m/s (cf., Gill 1980): Wave Dynamics (Linear) • L~1000km, U~10m/s (Charney 1963): Balanced Dynamics (Nonlinear) R.1. Nondimensional: =2L2/aU
Question: Are the Equatorial Wave Theories consistent with the Asymptotic Nondivergence?
A simple theoretical analysis: RMS Ratio between the Vorticity and the Divergence for Linear Equaotorial Wave Modes: <(divergence)2>1/2/<(vorticity)2>1/2 ? (Delayen and Yano, 2009, Tellus)
Linear Free Wave Solutions: RMS of divergence/vorticity cg=50m/s cg=12m/s
Linear Forced Wave Solutions(cg=50m/s): RMS of divergence/vorticity n=0 n=1
Asymptotically Nondivergent but Asymptotic Nondivergence is much weaker than those expected from linear wave theories (free and forced) Nonlinearity defines the divergence/vorticity ratio (Strongly Nonlinear)
Asymptotically Nondivergent Dynamics (Formulation): • Leading-Order Dynamics: Conservation of Absolute Vorticity • Higher-Order: Perturbation“Catalytic” Effect of Deep Convection Slow Modulation of the Amplitude of the Vorticity
Balanced Dynamics (Asymptotic: Charney) Qw Q=Q(q,… ) • divergence equation (diagnostic) barotropics -plane vorticity equation Rossby waves (without geostrophy): vH(0) } • hydrostatic balance: • continuity: w weak divergence weak forcing on vorticity (slow time-scale) • thermodynamic balance: w~Q: (free ride) • dynamic balance: non-divergent • vorticity equation (prognostic) • moisture equation (prognostic): q
Asymptotically Nondivergent Dynamics (Formulation): • Leading-Order Dynamics: Conservation of Absolute Vorticity: :Modon Solution?
Is MJO a Modon?: Absolute Vorticity Streamfunction A snap shot from TOGA-COARE (Indian Ocean): 40-140E, 20S-20N ? (Yano, S. Hagos, C. Zhang)
Last Theorem “Asymptotic nondivergence” is equivalent to “Longwave approximation” to the linear limit. (man. rejected by Tellus 2010, JAS 2011) Last Question: What is wrong with this theorem? Last Remark However, “Asymptotic nondivergence” provides a qualitatively different dynamical regime under Strong Nonlinearity. Reference: Wedi and Smarkowiscz (2010, JAS)
Convective Organizaton?: (Yano, Liu, Moncrieff 2012 JAS)
Convective Organizaton?: Point of view of Water Budget Precipitation Rate, P ? Column-Integrated Water, I
Convective Organizaton?: (Yano, Liu, Moncrieff 2012 JAS) ? Self-Organized Criticality Homeistasis (Self-Regulation)
Convective Organizaton?: (Yano, Liu, Moncrieff 2012 JAS)
Convective organization?: (Yano, Liu, Moncrieff, 2012, JAS) with spatial averaging for 4-128km:
Convective organization?: (Yano, Liu, Moncrieff, 2012, JAS)
Convective organization?: (Yano, Liu, Moncrieff, 2012, JAS): dI/dt = F - P
Convective organization?: (Yano, Liu, Moncrieff, 2012, JAS)
Self-Organized Criticality and Homeostasis: Backgrounds
Self-Organized Criticality: • Criticality (Stanley 1972) • Bak et al (1987, 1996) • Dissipative Structure (Gladsdorff and Prigogine 1971) • Synergetics (Haken 1983) • Butterfly effect (Lorenz 1963)
Homeostasis: • etimology: homeo (like)+stasis(standstill) • Psyology: Cannon (1929, 1932) • Quasi-Equilibrium (Arakawa and Schubert 1974) • Gaia (Lovelock and Margulis 1974) • Self-Regulation (Raymond 2000) • cybernetics (Wiener 1948) • Buffering (Stevens and Feingold 2009) • Lesiliance (Morrison et al., 2011)