1 / 12

Boundar Layer Meteorology Lecture 2

Boundar Layer Meteorology Lecture 2. Review chapter 1 of Garratt Terminology and Notation Review Some non-dimensional numbers Reynolds Averaging. Review chapter 1 of Garratt. Inner and outer layers (what’s with this, is the outer layer really part of the boundary layer?)

forbes
Télécharger la présentation

Boundar Layer Meteorology Lecture 2

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Boundar Layer Meteorology Lecture 2 • Review chapter 1 of Garratt • Terminology and Notation Review • Some non-dimensional numbers • Reynolds Averaging

  2. Review chapter 1 of Garratt • Inner and outer layers (what’s with this, is the outer layer really part of the boundary layer?) • Seasonal and geographic variations of the boundary layer’s character.

  3. Modeled Boundary Layer Depth

  4. Modeled Boundary Layer Depth

  5. Observed Boundary Layer Depth

  6. Terminology • Boundary Layer Regions: • Surface Layer • Mixed Layer • Residual Layer • Stable (Nocturnal Boundary) Layer • Entrainment Zone • Ekman Layer (Outer Layer) • Surface Layer

  7. Boundary Layer Regions

  8. Notation • Variables: T, Tv ,, v , , q, x, y, z, • Viscosity:  = du/dy; Tkg/(m s)=Pa/s • Kinetmatic viscosity: m2/s • Summation (Einstein) notation: see Stull handout (pp. 57-74). Note definitions of the Kronecker delta (and distinction between it and the unit vector), and the alternating unit tensor (Levi-Civita symbol) used to express the cross product.

  9. Some Non-Dimensional Numbers • Reynolds number:Re = VL/ • Reynolds number is ratio of acceleration (or “inertial force”) to friction force. It governs transition to turbulence (at high Reynolds numbers , e.g. about 2300 for pipes; highly variable!). • Richardson numbers: ratio of • Flux • Gradient: Ri = (g/ddz)/(du/dz)2 • Bulk

  10. Reynolds averaging and Reynolds Stresses t1 should be enough larger than t2 so that the average is independent of time.

  11. Reynolds averaging and Reynolds Stresses

  12. Understanding Reynolds Stress

More Related