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 dArologie Toulouse (France) 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 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 ! z = 1500 m Some climatological features (30-day averaged fields) P + z = 3000 m Temp. C (colorscale) -2 PVU tropopause (dashed) Zonal wind (dotted) SACZ vertical cross-section Mean daily vertical motion (06-24 UTC) S-N cross-section: z = z z 0 (km) z 0 z = 6000 m SACZ Mass budget computation: a post-processing method z Surface = air-parcels with common initial altitude z 0 x z0z0 Upward mass flux through z 0 between t 0 and t: Air-parcels that were initially below z 0 are finally above z 0 Mass flux between t 0 and t = Mass of the colored volume Model run: transport of a passive tracer initialized with the altitude, then Mass budget computation: what was performed 3000 m 6000 m 9000 m m m m m = flux UTC (up / down) Net flux = up - down For each day (simulation Day 1) Computation for 30 days: few seconds on a Linux PC ! Mass flux = dry air or water-vapour Qualitative comparison against rain satellite-retrievals (TRMM, 125x125 km) Mixed results, better with sub-grid cloud fraction ? To be tested 06 February heavy-rain over Bauru, good forecast ! 14 February active front, forecasted too late 28 February good ! diurnal convection period, not good 3-4 March not so bad Dry-air mass budget Criterion: Max( flux(9000m) + flux (12000m) ) Dry-air mass budget Criterion: Min( flux(9000m) + flux (12000m) ) Water-vapor flux: qualitative comparison against rain satellite retrievals (TRMM, 125x125 km) Better correlation with the observed precipitation Water-vapour mass budget Conclusions Numerical aspects 30 MesoNH runs in forecast mode: statistical approach over the period 05 Feb 05 Mar 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 Future work Work with better simulation sets Compare findings and observations Investigate the diurnal evolution of the vertical transport