1 / 15

LIDAR Observations of Terrain-induced Flow and Its Application in Airport Wind Shear Monitoring

LIDAR Observations of Terrain-induced Flow and Its Application in Airport Wind Shear Monitoring. CM Shun, CM Cheng & O Lee ICAM/MAP 2003. Background. Wind Shear: terrain disrupted flow; thunderstorms; sea breeze. Weather buoy (3). Weather Buoys. (1+2). TDWR. Sham Wat (2).

vaughan-mckenzie
Download Presentation

LIDAR Observations of Terrain-induced Flow and Its Application in Airport Wind Shear Monitoring

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. LIDAR Observations of Terrain-induced Flow and Its Application in Airport Wind Shear Monitoring CM Shun, CM Cheng & O Lee ICAM/MAP 2003 19-23 May 2003

  2. Background Wind Shear: terrain disrupted flow; thunderstorms; sea breeze Weather buoy (3) Weather Buoys (1+2) TDWR Sham Wat (2) Automatic Weather Stations over Lantau 19-23 May 2003

  3. LIght Detection And Ranging (LIDAR) System LIDAR Scanner Installed in mid-2002 IR (2 μm) → eye-safe ATC Building Roof-top 19-23 May 2003

  4. LIDAR in Tropical Cyclone 19-23 May 2003

  5. Jump Like Feature (11 Nov 2002) stagnant flow N = 0.0135 s-1 h = 465 m U0 ~ 5 ms-1 Nh/U0 ~ 1.3 > 0.85 (wave breaking) Weak inversion (0.4ºC) below 500 m jump Lo Fu Tau 465 m 100º Inversion near 3 km 19-23 May 2003

  6. Jump Like Feature (20 Jan 2003) N = 0.013 s-1 h = 465 m U0 ~ 6 ms-1 Nh/U0 ~ 1.0 > 0.85 (wave breaking) Inversion: 1.1&1.5ºC 500-700 m  = 3.6 K  = 291 K D ~ 600 m Fr = U0 / (g’D)½ ~ 0.7 M = h/D ~ 0.8 Schär & Smith (1993) Regime IIb reverse flow jump Lo Fu Tau reverse flow 095º Inversion at 500-700 m 19-23 May 2003

  7. Jump Structure22-min Sequence (@ 2 min) 095º 19-23 May 2003

  8. Vortex Shedding12-minute Sequence (@ 2 min) 100º 19-23 May 2003

  9. Springtime Wind Shear(5 March 2003) 19-23 May 2003

  10. Temperature Jump +4ºC Buoy (north) +5ºC Buoy (south) 19-23 May 2003

  11. Wind Changes (ES) Buoy (north) Buoy (south) Land Station (SW1) 19-23 May 2003

  12. Descent of Warm Jets 00 UTC 0317 UTC 20°C 20 25°C 297 K 19°C N = 0.02 s-1 h = 934 m (Lantau Peak) U0 19 ms-1 Nh/U0 1 (descending flow / hydraulic jump) • How to apply Fr under strong vertical shear? • Contribution of gap-flow? • Interaction between jets? 19-23 May 2003

  13. Time - Azimuth Plot of LIDAR radial velocity 19-23 May 2003

  14. Conclusions • Jump-like features & vortex shedding under stable conditions are revealed • Nh/U0 & Fr able to diagnose jump based on Schär & Smith (1993) • Springtime wind shear - interaction of descending S’ly jet (also a jump?) with surface E’ly jet • More work is needed to better understand phenomena (Nh/U0 & Fr in strong vertical shear; gap-flow dynamics) 19-23 May 2003

  15. Thank You! 19-23 May 2003

More Related