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Mega-grants for environmental challenges 24-26.05.2012

A ir-sea/land interaction: physics and observation of planetary boundary layers and quality of environment Mega-Grant, started November 1 st 2011 University of Nizhny Novgorod, Russia INSTITUTIONS-COLLABORATORS

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Mega-grants for environmental challenges 24-26.05.2012

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  1. Air-sea/land interaction: physics and observation of planetary boundary layers and quality of environment Mega-Grant, started November 1st 2011 University of Nizhny Novgorod, Russia INSTITUTIONS-COLLABORATORS Institute of Applied Physics RAS; Faculty of Geography of Moscow State University; Russian State Hydrometeorological University; A.M. Obukhov Institute of Atmospheric Physics RAS – RUSSIA // Danish Meteorological Institute – DENMARK // Finnish Meteorological Institute; Dept of Physics of University of Helsinki – Finland // Ben-Gurion University of the Negev – ISRAEL // Nansen Environmental and Remote Sensing Centre – NORWAY… WELCOME TO ADJOIN OUR PARTNERSHIP! Mega-grants for environmental challenges 24-26.05.2012

  2. Motivation and content

  3. Geophysical turbulence and planetary boundary layers (PBLs) Physics Geo-sciences New concepts of random and self-organised motions in geophysical turbulence PBLs link atmosphere, hydrosphere, lithosphere and cryosphere within weather & climate systems Revision of basic theory of turbulence and PBLs Improved “linking algorithms” in weather & climate models Progress in understanding and modelling weather & climate systems

  4. Geospheres in climate system Atmosphere, hydrosphere, lithosphere and cryosphere are coupled through turbulent planetary boundary layers PBLs (dark green lenses) PBLs include 90% biosphere and entire anthroposphere

  5. Role of planetary boundary layers (PBLs): TRADITIONAL VIEW “Surface fluxes” through AIR and WATER (or LAND) interfaces fully characterise interaction between ATMOSPHERE-OCEAN/LAND atmosphere ocean Monin-Obukhov similarity theory (1954) (conventional framework for determining surface fluxes in operational models) disregards non-local features of both convective and long-lived stable PBLs http://www.jpgmag.com/photos/1006154

  6. Role of PBLs: MODERN VIEW Because of very stable stratification in the atmosphere and ocean beyond the PBLs and convective zones, strong density increments inherent in the PBL outer boundaries prevent entities delivered by surface fluxes or anthropogenic emissions to efficiently penetrate from the PBL into the free atmosphere or deep ocean. Hence the PBL heights and the fluxes due to entrainment at the PBL outer boundaries essentially control extreme weather events (e.g., heat waves associated with convection; or strongly stable stratification events triggering air pollution). This concept (equally relevant to the hydrosphere) brings forth the problem of determining the PBL depth and the turbulent entrainment in numerical weather prediction, air/water quality and climate modelling. Atmosphere Atmosphere PBL Ocean PBL http://www.jpgmag.com/photos/1006154 Ocean

  7. Very shallow boundary layer separated form the free atmosphere by capping inversion PBL height visualised by smoke blanket (Johan The Ghost, Wikipedia)

  8. PBL height and air quality

  9. Tasks Geophysical turbulence and PBLs Non-local nature  Revision of traditional theory  Improved practical applications (SZ) Atmospheric electricity Convective PBLs, thunderstorms, upper atmosphere  role in global electric circuit  applications (EM) Air-sea interaction Processes at air-sea interface (theory, lab and field experiments)  application to hurricanes, storms (YuT) Internal waves Interaction with turbulence, wave-driven transports (ocean, ionosphere)  role in climate machine (AK) Chemical weather / climate Fires and modelling air pollution  troposphere and middle atmosphere (AF) New methods of radio-physical observations Instruments to respond new challenges  turbulence, organised structures, chemical composition  commercialisation (AF, AU) Education and young-scientist programme  new PhD, Dr.Sci. http://www.jpgmag.com/photos/1006154

  10. PBL and turbulence problems Self-organisation of turbulent convection Failure of the MO similarity theory  non-local resistance and heat/mass transfer laws (free and forced convection regimes); growth rate of and turbulent entrainment into convective PBLs Non-local nature of stably stratified PBLs ”Long-lived stable” and “conventionally neutral” very shallow and therefore sensitive (typical of Polar areas and over ocean); diagnostic and prognostic PBL-height equations Dead locks in and new concept of turbulence closure Potential energy, self-preservation of stably stratified turbulence  no critical Richardson number; new “weak turbulence” regime with diminishing heat transfer (everywhere in the atmosphere and hydrosphere beyond PBLs and convective zones) http://www.jpgmag.com/photos/1006154

  11. Cloud streets visualising updraughts in convective rolls Photo J. Gratz Turbulent convection LES I. Esau In the atmosphere In LES

  12. Development of convective cloudsSelf-organised cells in the atmosphere Гора Леммон, Аризона

  13. Cloud systems over North Polar Ocean Convective cells Weak wind  free convection‏ Convective rolls Strong wind  forced convection

  14. Self-organisation Self-organisation in viscous convection isknown since Benard (1900) and Rayleigh (1916) It is obviously presents in turbulent convection but missed in essentially local classical theories: • Heat and mass transfer law Nu ~ Ra1/3 • Prandtl theory of free convectionWc= (βFsz)1/3 • Monin-Obukhov similarity theory L= τ3/2 (βFs)-1 and in all parameterizations based on these theories Revision of the theory is demanded

  15. Example of solved problem Non-local theory of convective heat and mass transfer

  16. Organised cell in turbulent convection (disregarded in classical theory) Air-borne measurements, calm sunny day over Australian desert: arrows – winds; lines – temperatures (Williams and Hacker, 1992)

  17. Heat and mass transfer in free convection:non-local theory Self-organisation Convective wind pattern includes the convergence flow towards the plume axes at the surface Near-surface internal boundary layer ”minimum friction velocity U*(Businger,1973) Strongly enhanced heat/mass transfer

  18. Heat-transfer coefficient Blue symbols observations Red symbolsLES Linetheory Classical theory (Nu = C0Ra1/3) disregards dependence onh/z0 and underestimates heat transfer over rough surfaces up to 2 orders of magnitude

  19. Convective heat/mass transfer: conclusions Classical (local) theory disregards self-organisation of turbulent convection and strongly underestimates heat/mass transfer in nature Developed Non-local theory of free convection(cells, weak winds) Essential dependence of heat/mass transfer on the ratio of boundary-layer depth to roughness length (h/z0u)New turbulent entrainment equation accounting for IGW mechanism Under development  Non-local theory of forced convection (rolls at strong winds) Applications to modelling air flows over warm pool area in Tropical Ocean (free convection / known)  openings in Polar ocean (forced convection / prospective)  urban heat islands, deserts, etc. (prospective

  20. 2h Convection: principal statement Convective structures are supplied with energy through inverse energy cascade(from smaller to larger eddies). They resemble secondary circulations rather then large turbulent eddies Cloud streets visualising convective rolls stretched along the strong wind (Queensland, North Coast, Australia, Wikimedia Commons; photo by Mick Petroff) In both figures h ~ 103мis the height of convective layer Vertical cross-section of a convective cell at weak wind over Australian desert (airborne observations by Williams and Hacker, 1992)

  21. turbulence in stable stratification Very shallow long-lived stable boundary layer over cold Lake Teletskoe (Altay, Russia) on 28 August 2010 (photo by S. Zilitinkevich). Smoke blanket visualises upper boundary of the layer

  22. Example of solved problem Non-local theory of long-lived stably-stratified Planetary boundary layers(PBLs) S. Galmarini, JRC

  23. Stable and neutral PBLs Traditional theory (adequate over land at mid latitudes) • is valid in the presence of pronounced diurnal course of temperature • recogniseed only two types of stably or neutrally stratified PBL, REGARDLESS STATIC STABILITY AT PBL OUTER BOUNDARY: stable (factually nocturnal stable– capped by residual layer) neutral (factually truly neutral– capped by residual layer) Non-local theory (2000-2010) • accounted for the free flow-PBL interaction through IGW or structures • led to discovery of additional types of PBL: long-lived stable(50 % at high latitudes) conventionally neutral(40 % over ocean) • both proved to be much shallower than mid-latitudinal PBLs

  24. Temperature stratification in (a) nocturnal and (b) long-lived stable PBLs

  25. The effect of the free flow stability on the PBL height ● LES ● observations Traditional (local) theory New non-local theory (Z et al., 2007)‏ Nocturnal PBL Marine PBL Polar PBL

  26. Stable PBLs: Conclusions Non-local nature due to long-lived structures and/or internal waves Triggering air pollution the shallower PBL  the heavier air pollution Sensitivity to thermal impacts the shallower PBL  the stronger microclimate response  triggering global warming in stable PBLs: in winter- and night-time at Polar and high latitudes

  27. Features of ”scientific revolution”(Tomas Kun, Structure of scientific revolutions, 1962‏) TRADITIONAL PARADIGM Forward cascade Fluid flow =mean (regular) +turbulence (chaotic) Applicable to neutrally- and weakly-stratified flows Crises of traditional theoryALTERNATIVE PARADIGM Forward(randomisation) and inverse (self-organisation) cascades Fluid flow =mean (regular) +Kolmogorov’sturbulence (chaotic) +anarchic turbulence (with inverse cascade) +organised structures (regular) NON-LOCAL THEORY Self-organisation of turbulent convection Structures and internal waves in stable PBLs Non-local closures Much work to be doneNumerous simple unsolved problems XX XXI

  28. Towards ”scientific revolution” Marie Curie Chair – PBL (2004-07); ERC-IDEAS PBL-PMES (2009-13); RU-Gov. Mega-Grant – PBL (2011-13) Co-authors from > 30 groups / 15 countries Finland(FMI, U-Helsinki); Russia((Nizhny Novgorod State Univ., Obukhov Inst. Atmos. Phys., Rus. State Hydro-met. Univ.) Sweden(MIUU, MISU, SMHI); Norway (NERSC-Bergen); Denmark (RISOE National Lab, DMI-Copenhagen); Israel (Ben-Gurion Univ., Weizmann Inst. Advance Studies); UK (Univ. College London, Brit. Antarctic Sur. Cambridge); USA (Arizona State Univ., Univ. Notre Dame, NCAR, NOAA); Brazil(UNIPAMA, Univ.-Rio Grande, Univ.-Santa Maria); Greece (Nat. Obs., Univ.-Athens); Germany (Univ.-Freiburg); Estonia (Tech. Univ.-Tallinn); Switzerland (SFIT, EPF-Lausanne); France (Univ.-Nantes); Croatia (Univ.-Zagreb)

  29. Thank you for your attention and WELCOME TO ADJOIN OUR PARTNERSHIP!

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