Bauru November 2004 Modelling interpretation of in situ H2O, CH4 and CO2 measured by  SDLA balloon borne instrument (SF2 and SF4 flights). N. Huret(1),G. Durry (2),S. Freitas(3),M.Pirre(1), A. Hauchcorne(2) (1) LPCE/CNRS,France (2)IPSL, Service d’Aéronomie du CNRS,France (3)CPTEC, Brazil

Bauru November 2004 OBJECTIVES To understand how the convection can modify the Upper Troposphere (UT) and the Tropical Transition Layer (TTL) ? What type of model we have to use to investigate the tropical UT and TTL ? Previously in polar region and at mid-latitude we used insentropic trajectories from ECMWF

Bauru November 2004 Mesoscale interpretation RAMS/CPTEC model outputs Operational mesoscale model (40 km x 40 km) 3D trajectory code (Freitas et al. 2000) –4 days backward trajectories –10-20 km every km –Temperature, pressure, water vapor, liquid water content, solid water content, vertical velocity

Bauru November 2004 SF2 flight, 13 February 2004 Upper troposphere : Air mass ascent from 8 to 10.5 km, 20h before the measurements Tropical Transition Layer : nothing special

Bauru November 2004 SF4 flight, 24 February 2004 Tropical Transition Layer : very strong uplifting from the ground to 17 km 80h before the measurements

Bauru November 2004 Is SF4 17km trajectory realistic ? Very strong uplifting from the ground to 17 km, 80h before the measurements Does a strong convective system exist ? Accumulated precipitation map from RAMS and TRMM satellite data GOES-E satellite cloud MAP Does RAMS mesocale model predict this convective system at the good location ?

Bauru November days before the SF4 measurements A strong convective system exists at the location of the uplifting SF4 RAMS Validation

Bauru November 2004 RAMS validation : accumulated precipitation RAMS outputs / TRMM satellite data This case was very convective because of the South Atlantic Convergence Zone activity RAMS predictions are validated

Bauru November 2004  SDLA water vapor measurements SF2/ SF4 comparison a water vapor bubble from  SDLA (17 km) for SF4 can be due to a deep convective system seen on GOES satellite maps and simulated using RAMS mesocale model The convection affects the TTL

Bauru November 2004 RAMS(40 km) grid close to Bauru Profiles extracted at each grid point in this region Bauru

November 2004 RAMS water vapor profiles Water vapor excess in the TTL Very dry layer In the UT : SF4 Good agreement between RAMS simulation and measurements Except : between 14 and 16 km but not critical between 8-10km in the UT

Bauru November 2004  SDLA-RAMS temperature profiles comparisons

Bauru November 2004 Mixing ratio RAMS fields Bauru Strong water vapor gradient south of Bauru The dry layer is predicted by the RAMS model Bauru

November 2004 MIMOSA PV contour advection model Hauchecorne et al On isentropic surfaces MIMOSA calculates the Potential vorticity evolution from ECMWF wind fields. Global scale transport 340 K isentropic surface

Bauru November 2004 MIMOSA Outputs PV filament coming from low stratopshere mid-latitude with PVU > 2 Large scale isentropic transport

Bauru November 2004 SF4 : CH 4, CO 2, H 2 O and O 3 (sonde)

Bauru November 2004 CONCLUSIONS SF4 flight Strong uplifting from the ground to the TTL (17 km) due to convection Mesoscale transport process Isentropic transport from mid- latitude to the tropical UT (8-10 km) Large scale transport SF4 profiles

Bauru November 2004 Many thanks TROCCIBRAS partners team from USP and CPTEC –S. Freitas –P. Leite da Silva Dias