1 / 15

F. Gheusi, J.-P. Cammas, J.-P. Chaboureau, J. Duron, C. Mari, P. Mascart and J.-P. Pinty

A regional-model « climatology » of vertical mass and water-vapour transport for the Hibiscus-Troccinox-Troccibras campaign 2004. F. Gheusi, J.-P. Cammas, J.-P. Chaboureau, J. Duron, C. Mari, P. Mascart and J.-P. Pinty Laboratoire d’Aérologie Toulouse (France).

yardley-carver
Download Presentation

F. Gheusi, J.-P. Cammas, J.-P. Chaboureau, J. Duron, C. Mari, P. Mascart and J.-P. Pinty

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. A regional-model « climatology » of vertical mass and water-vapour transport for the Hibiscus-Troccinox-Troccibras campaign 2004 F. Gheusi, J.-P. Cammas, J.-P. Chaboureau, J. Duron, C. Mari, P. Mascart and J.-P. Pinty Laboratoire d’Aérologie Toulouse (France)

  2. Meso-NH forecast support during the campaign (1) Resolution = 30 km Domain 3000 km x 3000 km « Radar » rectangle Mass budget (arbitrarily) restricted to this area

  3. Meso-NH forecast support during the campaign (2) • Daily time-period considered for • vertical air-displacement • integration of mass budgets 06 UTC 24 UTC Set of 30 simulations from 05 Feb to 05 Mar Makes possible some statistics !

  4. Some climatological features(30-day averaged fields) P + wind @ z = 3000 m Temp. °C (colorscale) -2 PVU tropopause (dashed) Zonal wind (dotted) vertical cross-section SACZ Wind-strength @ z = 1500 m

  5. Mean daily vertical motion (06-24 UTC) S-N cross-section: Dz = z – z0 (km) z0 (m) @ z = 6000 m SACZ

  6. Mass budget computation: a post-processing method Model run: transport of a passive tracer initialized with the altitude, then … • Upward mass flux • through z0 • between t0 and t: • Air-parcels that • were initially below z0 • are finally above z0 z z0 Mass flux between t0 and t = Mass of the colored volume x Surface = air-parcels with common initial altitudez0

  7. Mass budget computation: what was performed For each day (simulation Day 1) 21000 m 18000 m = flux 06-24 UTC (up / down) 15000 m Net flux = up - down 12000 m 9000 m Mass flux = dry air or water-vapour 6000 m 3000 m Computation for 30 days: few seconds on a Linux PC !

  8. Qualitative comparison against rain satellite-retrievals (TRMM, 125x125 km²) 28 February good ! 06 February heavy-rain over Bauru, good forecast ! 14 February active front, forecasted too late… 3-4 March not so bad diurnal convection period, not good… Mixed results, better with sub-grid cloud fraction ? To be tested…

  9. Dry-air mass budget

  10. Dry-air mass budget Criterion: Max( flux(9000m) + flux (12000m) )

  11. Dry-air mass budget Criterion: Min( flux(9000m) + flux (12000m) )

  12. Water-vapor flux:qualitative comparison against rain satellite retrievals (TRMM, 125x125 km²) Better correlation with the « observed » precipitation

  13. Water-vapour mass budget

  14. Conclusions Numerical aspects • 30 MesoNH runs in forecast mode: statistical approach over the period 05 Feb – 05 Mar 2004. • Flux computation based on • On-line passive transport of initial-coordinate tracers • Low-cost and highly adaptable post-processing (PC) Vertical motion « model climatology » • Subsidence in the lower troposphere, S of the SACZ • Largest ascent just below the tropopause, N of the SACZ • Slight but significant subsidence above the tropopause • convergence in the TTL, no export in the stratosphere Vertical mass budget • Downward flux in the lower stratosphere • Upward flux maximum at 9000m (6000m for WV) • Mass and humidity convergence in the TTL

  15. Future work • Work with better simulation sets • Compare findings and observations • Investigate the diurnal evolution of the vertical transport

More Related