Summer School Rio de Janeiro March MICROMETEOROLOGY Amauri Pereira de Oliveira Group of Micrometeorology

2 Topics 1.Micrometeorology 2.PBL properties 3.PBL modeling 4.Modeling surface-biosphere interaction 5.Modeling Maritime PBL 6.Modeling Convective PBL

Micrometeorology

4 Space and time scales Adapted from Stull (1988). Microscale the relevant phenomena is TURBULENCE in the Planetary Boundary Layer (PBL). Global Sinoptic Mesoscale Microscale

5 Micrometeorology Micrometeoroly is the part of meteorology that study the atmospheric phenomena that occurs in the spatial scale smaller than 2 km and time scale smaller than 1 hour. Meteorological Micro scale

6 Turbulence Among all the physical process that has relevance to micrometeorology, turbulence is the most important and complex one.

7 Turbulence Turbulence is the one of the unsolved problems in Physics.

8 1 million dollar prize! Fonte: http//

9 Very brief historical description of turbulence First description of turbulence goes back to XV century, draw of Leonardo da Vinci ( ). Fonte:

10 Osborne Reynolds In 1880´s begins “officially” the scientific investigation of turbulence with Irish Engineer Osborne Reynolds ( ). Reynolds, O., An experimental investigation of the circumstances which determine whether the motion of water shall be direct or sinuous, and the law of resistance in parallel channels. Philos. Trans. Roy. Soc. London 174 (1883) 935–982.

11 Ludwig Prandtl In 1905, German physicist, Ludwig Prandtl ( ) introduced the concept of Boundary Layer in fluid dynamics. Prandtl, L., 1905: “On the motion of fluids with very little friction”. Anderson Jr, J.D., 2005: Ludwig Prandtl´s Boundary Layer. Physics Today. December 2005,

12 Geoffrey Ingram Taylor In 1910, English physicist, Geoffrey Ingram Taylor ( ) set down the fundamental ideas about turbulent motion using for the first time atmospheric turbulence measurements carried out with hot wire anemometers. Taylor, G.I., Eddy motion in the atmosphere. Philos. Trans. Roy. Soc. London A 215 (1915) 1– 26.

13 Lewis Fry Richardson In the 1920, English mathematician Lewis Fry Richardson ( ) proposed the “law of 4/3” and introduced the concept of cascade of energy. Richardson, L. F., Atmospheric diffusion shown on a distance-neighbor graph. Proc. Roy. Soc. London A 110(756) (1926) 709–737.

14 Andrei Nikolaevich Kolmogorov In 1940´s the Physicist Russian Andrei Nikolaevich Kolmogorov ( ) published the USSR the theory of small scale turbulence. Kolmogorov, A.N., Local structure of turbulence in an incompressible fluid at very high Reynolds numbers. Dokl. Akad. Nauk SSSR 30 (1941) 299–303. Kolmogorov, A.N., Energy dissipation in locally isotropic turbulence. Dokl. Akad. Nauk SSSR 32 (1941) 19–21.

15 George Keith Batchelor in 1950 Australian Mathematician, George Keith Batchelor ( ), proposed a theory of the homogeneous turbulence. Batchelor, G.K., The Theory of Homogeneous Turbulence. The University Press, Cambridge, UK (1953), reprinted 1956.

16 More recently From late 1950´s began the large micrometeorological field experiments; –Most famous: Kansas (EUA) and Wangara (Australia) experiments; –These field experiments allow to verify the universality of theory of similarity Monin-Obukov, Free Convection, etc); –Beginning of the observational phase of Micrometeorology.

17 Flow visualization techniques Geophysical and laboratory turbulence Source: Remote Sensing: Satellite Image of von Karman vortex “esteira” produced by an island in the

18 Analogical Modeling Wind Tunnel Fonte:

19 Numerical modeling Direct numerical simulation. Grids: Source: Moin and Mahesh, 1998.

20 Actual stage of development Lumley, J. L. and Yaglom, A. M., 2001: A century of turbulence. Flow. Turbulence and Combustion, 66,

21 Micrometeorology Micrometeorology can be considered one of the most challenging areas of meteorology.

22 Weather and climate forecast Environmental damage mitigation (Air pollution, flooding, urban heat island, etc) caused by anthropogenic surface modification Better representation of surface-atmosphere interactions over heterogeneous and complex surfaces (urban, rural, forest, ocean, etc.) Relevance