1 / 22

Testing of Non-local Turbulent Length-Scale Formulation in 3D COSMO-RU Model: Comparison with Profilers and Radiosondes

This study examines the performance of a non-local turbulent length-scale formulation in the 3D COSMO-RU model by comparing it with profiler and radiosondes data. Differences in temperature, humidity, cloud cover, and wind fields between the variants with local and non-local turbulence length scales are analyzed.

gaillard
Download Presentation

Testing of Non-local Turbulent Length-Scale Formulation in 3D COSMO-RU Model: Comparison with Profilers and Radiosondes

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. Testing of the non-local turbulent length-scale formulation within 3D COSMO-RU model, comparison with profilers and radiosondes dataVeniamin Perov and Oleg EvteevHydrometcentre of Russia

  2. z TKE Schematic view of a turbulent length scale (mixing length)scheme based on a parcel displacement (BL89) for a boundary layer scheme of the COSMO model

  3. Turbulent length scale based on a parcel displacement scheme Blackadar formula, locall

  4. Potential temperature profiles for local L (blue) and nonlocal L(red),Moscow 12h, 17.07.09

  5. Difference of T2M fields (new – ref), COSMO-RU, 19.07.2009

  6. Differences for T2M fields (nonlocal L minus local L), 12h, 170709,Full area

  7. Differences for T2M fields (nonlocal L minus local L), 12h, 17072009,Moscow area

  8. Differences for T2M fields (nonlocal L minus local L), left and total cloud cover,right , Black Sea coastal region

  9. Differences for TD2M fields (nonlocal L minus local L), 12h, 17072009,Moscow area

  10. Differences for U10M fields (nonlocal L minus local L), 12h, 17072009,Moscow area

  11. Mesoscale modeling in mountain region • Mesoscale modeling in mountain area should include simulations of main processes in this domain. These are formation of the regional slope winds, blocked flow, deviated flow, sheltering effect after obstacle, generation of turbulence by wind shear at the lower part of flow. • In the upper part of flow it will be generation of turbulence by roughness, mountain waves and generation of turbulence by mountain wave breaking. • For high mountains we need also to take into account a tropopause perturbation. All these processes require the use of three-dimensional turbulence and the non-use of simple diagnostic formulas for turbulence length scale (mixing length). • In this case, together with the equation for the turbulent kinetic energy (TKE) will have to use the equation for mixing length or equation for the dissipation of TKE.

  12. Turbulence and convection in mountain region

  13. Main results • Algorithm for computing the nonlinear turbulence length scale based on displacement method of air parcel (BL89) was developed. A new algorithm for calculation turbulence length scale has a more rigorous physical basis in comparison with the algorithm currently used (Blackadar formulae). • Algorithm was impact in module TUBDIFF of main COSMO program • Calculations were performed for convective situations (July 2009) by full 3-D COSMO model. Results showed differences in fields of temperature, humidity, clouds and wind between variants with local (reference) and nonlocal turbulence length scales. • An article for publication is prepared base on the current work.

More Related