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TTL modeling workshop, Victoria Emmanuel Rivière (1), V. Marécal (2), and contribution from the HIBISCUS/TROCCIBRAS participants 1 GSMA/ CNRS and Université.

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Presentation on theme: "TTL modeling workshop, Victoria Emmanuel Rivière (1), V. Marécal (2), and contribution from the HIBISCUS/TROCCIBRAS participants 1 GSMA/ CNRS and Université."— Presentation transcript:

1 TTL modeling workshop, Victoria Emmanuel Rivière (1), V. Marécal (2), and contribution from the HIBISCUS/TROCCIBRAS participants 1 GSMA/ CNRS and Université de Reims Champagne- Ardenne, France 2 LPCE/ CNRS and Université d’Orléans, France Modeling deep convection and chemistry in the continental tropics

2 TTL modeling workshop, Victoria  Introduction +What drives the UT/TTL air composition when convection occurs ? +What is specific to continental deep convection ? (with respect to oceanic deep convection)  Review : continental tropical campaigns / modeling tools  3D mesoscale Modelling in the Frame of Hibiscus  Conclusion Outline

3 TTL modeling workshop, Victoria Introduction What drives the composition of the upper troposphere and the TTL when deep convection occurs ? UTLS TTL stratosphere Boundary layer free troposphere Tropics Mid-latitudes tropopause deep convection 11 km 17 km 0 km Homogeneous chemistry LNOx emissions Emissions STE slow ascent waves Additional O 3 production O3O3 Aqueous / ice chemistry (+ scavenging) scavenging Vertical transport « overshoot » LNO x

4 TTL modeling workshop, Victoria Introduction Modeling the chemical composition of the continental tropics need to account for all these processes. Homogeneous chemistry Vertical transport by deep convection LNO x Emissions STE Aqueous / ice chemistry (+ scavenging) These processes occur both over the oceans and the continents

5 TTL modeling workshop, Victoria What is specific to continental deep convection ? (with respect to maritime deep convection) Emissions at the surface : -Continental : NO x, VOCs, CO +…. -Ocean (clean atmosphere) +sea salt aerosols Type of convection (organized or not) : - convection more severe over the continents  Higher altitude (with possibly higher LNO x production) - Overshoot occurrence mainly above continents (direct effect of deep convection on the LS composition ?)

6 TTL modeling workshop, Victoria Liu and Zipser, JGR, 2005 from TRMM observations Higher convection over continents. Overshoots mainly above continents. ‰ Overshoot occurrence What is specific to continental deep convection ? (with respect to maritime deep convection) #2

7 TTL modeling workshop, Victoria Introduction Modeling the chemical composition of the continental tropics need to account for all these processes. Homogeneous chemistry Aqueous / ice chemistry (+ scavenging) Vertical transport by deep convection LNO x Emissions STE VOCs, NOx, CO… Higher Overshoots more likely Enhanced production because of a more severe convection

8 TTL modeling workshop, Victoria Global emissions data from EDGAR, GEIA, RETRO Temporal resolution : annually (EDGAR), Seasonly/annually (GEIA), monthly (RETRO) Resolution 1° x 1° EDGAR and GEIA 0.5° x 0.5 for RETRO Discrimination anthropogenic/biogenic : importance for biomass burning / wet season EDGAR Emission data to be used in modeling studies

9 TTL modeling workshop, Victoria Impact of the emissions on the UT composition Cloud scale simulations with RAMS-chemistry 50 km x 50 km grid 1km x 1km resolution 3h simulation Emission from EDGAR : - Values from Sao Paulo - Values from Bauru state of Sao Paulo (~10 times less)

10 TTL modeling workshop, Victoria  Intro : +What drives the the UT/TTL air composition when convection occurs ? +What is specific to continental deep convection ? (with respect to oceanic deep convection)  Review (non-exhaustive) : continental tropical campaigns / modeling tools  3D mesoscale Modelling in the Frame of Hibiscus  Conclusion

11 TTL modeling workshop, Victoria Field Campaigns in the continental Tropics A brief review (not exhaustive)  HIBISCUS/TROCCINOX/TROCCIBRAS – TROCCINOX 2  SHADOZ (O 3 sondes in the tropics, continental sometimes)  TRACE-A, (mostly oceanic, continental in Southern Africa) Balloon and aircraft plateforms. O 3, H 2 O, CH 4, NO 2, BrO, NO x and NO y CO 2  Measurements onboard commercial aircraft O 3 and H 2 O MOZAIC over Brazil up to 10-12 km (Franckfurt  Sao Paulo)  ABLE-2 Central Brazil dry and wet season : O 3, CO, NO, PAN.  TROPOZ South America, O 3, NO, CO. aircrafts Balloons, sondes

12 TTL modeling workshop, Victoria Fields Campaign in the continental Tropics A brief review #2 Lack of data over the continental tropics especially during the wet season Emmons et al., JGR, 2000. O 3 airborne measurements 6-8 km

13 TTL modeling workshop, Victoria Fields Campaign in the continental Tropics to come  TERESINA SCOUT-O3 September October 2007 over equatorial Brazil during the transition period : biomass burning + deep convection. Balloon : O 3, H 2 O, CH 4, NO y, NMVOC, Cl y A brief review #3  AMMA West Africa during the monsoon + SCOUT-O3 Aircrafts and balloons : O 3, H 2 O, CH 4, NO x, NO y, VOC. Summer 2006.

14 TTL modeling workshop, Victoria modeling tools A brief review  Large numbers of modeling approach 1D, 2D, 3D… : choice depends on the process to study  Computing efficiency is increasing  full regional scale studies dynamics/microphysics/chemistry are now possible. New point of view  Coupling between microphysics/dynamics/chemistry is expensive  cloud scale studies or off-line chemistry  Cloud scale studies are very useful for larger scale studies subgrid parameterization

15 TTL modeling workshop, Victoria modeling tools A brief review  3D modelling with chemistry : regional and global scale  Labrador et al GRL (2004) : impact of LNO x at global scale  3D Mesoscale modelling with on-line chemistry. Marécal et al., ACP, 2006 and Rivière et al., ACP 2006. Pre-HIBISCUS and HIBISCUS campaign, Brazil (continental tropics during the convective season).  Similar tools : Meso-NH chemistry to be run for the AMMA campaign Catt-BRAMS to be run for the Teresina campaign + …

16 TTL modeling workshop, Victoria  Intro : +What drives the the UT/TTL air composition when convection occurs ? +What is specific to continental deep convection ? (with respect to maritime deep convection)  Review (non-exhaustive) : continental tropical campaigns / modeling tools  3D mesoscale Modelling in the Frame of Hibiscus  Conclusion

17 TTL modeling workshop, Victoria 3D mesoscale Modelling in the Frame of Hibiscus The RAMS chemistry model : Mesoscale model (Colorado State University) with on-line chemistry. Nested grid simulation possible. Grell convection parameterization (Thanks to S. Freitas) Microphysics with 7 types of hydrometeors : liq droplet, rain, pristine ice, Hail, Graupel, Agregates, Snow. Gas phase chemistry : 30 species and 70 reactions. Simplified scheme from MOCA (B. Amont). Emission routine for VOCs, NO x, and CO. Liquid phase for 10 soluble species (HNO 3, H 2 O 2 …) based on Grégoire et al. 1996. Adsorbsion on ice not yet included. LNOx parameterisation from Pickering et al., 1998 LaMP

18 TTL modeling workshop, Victoria 3D mesoscale Modelling in the Frame of Hibiscus Our aim : study the impact of continental convective systems on the chemical composition (UT and TTL) First step: check that the meteorological simulation of the convective system is correct. Convection on continental region is highly dependent on the soil moisture (more difficult than oceanic cases) Cloud top Precipitations Radar observations Water vapor (comparison with balloon-borne measurements HIBISCUS from Bauru, Brazil in 2003 and 2004. 2004 with TROCCINOX/ TROCCIBRAS. Pre-HIBISCUS in 2001

19 TTL modeling workshop, Victoria 3D mesoscale Modelling in the Frame of Hibiscus Meteorological validation of the meteorological reseults Observations from TRMM B-RAMS Model February 14, 2004 (V. Marécal et al., submitted 2006) 1 grid simulation 20 km x 20 km with B-RAMS : organized case Accumulated rainfall rate (15 h)

20 TTL modeling workshop, Victoria Observations Bauru radar model Meteorological validation of the meteorological reseults February 8, 2001 (V. Marécal et al., ACP 2006) 2 grid simulation with RAMS : unorganized case Accumulated rainfall rate 3D mesoscale Modelling in the Frame of Hibiscus More difficult to model

21 TTL modeling workshop, Victoria 3D mesoscale Modelling in the Frame of Hibiscus Chemical results from the February 8, 2001 case (see Marecal et al. 2006 & Rivière et al., 2006, ACP for details) Very severe unorganized convective case 42 hour simulations ◊ With LNO x ◊ Without LNO x 2 nested grids, 628 km x 608 km with 4km resolution for the fine grid, 0.5 km vertical resolution in the UTLS

22 TTL modeling workshop, Victoria 3D mesoscale Modelling in the Frame of Hibiscus Chemical results from the February 8, 2001 case (see Marecal et al. 2006 & Rivière et al., 2006, ACP for details) LNOx no LNOx Initial Ozone precursors are transported up to 13-15 km Mean NOx

23 TTL modeling workshop, Victoria 3D mesoscale Modelling in the Frame of Hibiscus Ozone time evolution in the fine grid – comparison with DMI sondes mean of DMI ozonesondes from Bauru mean RAMS O 3, fine grid after convection mean RAMS O 3, fine grid before convection Range of the DMI-O3 measurments 0.01 0.10 1.00 10.0 Ozone (ppmv) 8 11 14 17 20 Altitude (km) Correct behavior of the model in the TTL Increase of ozone in the TTL related to convection activity TTL

24 TTL modeling workshop, Victoria 3D mesoscale Modelling in the Frame of Hibiscus Ozone budget in the TTL Dynamics / Chemistry In 10 30 molec O 3 total Top (17 km ) Bottom (13 km) HorizontalChemistry 24 h period 97.523.368.7-23.128.7 Convective Period (8 h) 11.034.252.2-91.816.4 Wave breaking ? Importance of LNO x Convection Mass conservation

25 TTL modeling workshop, Victoria 3D mesoscale Modelling in the Frame of Hibiscus Wave generated by convection – impact on STE ? Vertical velocity at the tropopause level

26 TTL modeling workshop, Victoria Conclusion  Modelling chemistry related to continental tropical deep convection with a mesoscale model is a chalenging task. ◊ Meteorology is difficult to model (dependency on the soil moisture) ◊ Quality of the emission data ◊ Expensive to compute : uncomplete chemistry  3D mesoscale models with chemistry are powerful tools to study the chemistry of the TTL / continental deep convection ◊ Full complexity of convective systems ◊ Most of the processes responsible for the TTL composition can be taken into account

27 TTL modeling workshop, Victoria Conclusion #2  Developement within RAMS  Catt-BRAMS :  Lack of measurements to compare model simulations with More campaigns needed  AMMA / SCOUT-O3  TERESINA 2007 (SCOUT-O3) ◊ Change of chemical solver (longer timestep)  more species and more reactions (in collaboration with S. Freitas and K. Longo, CPTEC) ◊ gas adsorption on ice  On going work for 2 HIBISCUS cases including trapping of HNO 3 in ice particles. Waves generated by convection  For a severe case during pre-HIBISCUS 2001 importance of dynamics + LNO x in the O 3 concentration in the TTL  looking forward to seeing the conclusion of TROCCINOX for the evaluation of parameterizations

28 TTL modeling workshop, Victoria THANK YOU

29 TTL modeling workshop, Victoria 3D mesoscale Modelling in the Frame of Hibiscus Chemical regime - horizontal cross section at 13 km NOx VOCs VOCs/NOx OH 22 UT Maximum of convection

30 TTL modeling workshop, Victoria 3D mesoscale Modelling in the Frame of Hibiscus

31 TTL modeling workshop, Victoria Emission data to be used in modeling studies EDGAR RETRO 1°x1° 0.5°x0.5° NO x over Brazil

32 TTL modeling workshop, Victoria modeling tools A brief review  1D approach to be included in 3D models Courtesy : S. Freitas and K. Longo (CPTEC, Brazil)) ◊ Freitas et al., 2006 for plume rise parameterization (application to pyro- cumulus, ) 8 km Plume-rise due to the strong buoyancy of the hot gases / aerosols emitted during fires Use a 1D Cloud Resolving Model embedded in each column of a larger- scale atmospheric-chemistry model. Combined effect of biomass burning and deep convection

33 TTL modeling workshop, Victoria modeling tools (same for continental & maritime deep convection)  1D approach : dynamics + off-line chemistry (Folkins et al., 1997)  Able to retrieve a typical « S-shaped » profile of O 3 in tropical UT/LS (including continental regions) using SHADOZ ozone sondes  To investigate the impact of a particular process on the atmospheric composition, cloud scale studies are carried out. - Example of scavenging and rainout:  2D cloud model to study liquid chemistry/gas uptake on ice /scavenging (Yin et al., ACP, 2001; Yin et al., ACP, 2002) in maritime and continental deep convection.  3D cloud model to study the chemical redistribution of variable soluble species by continental deep convective clouds (Barth et al., JGR 2001)  1D cloud model to study scavenging of soluble gases (Mari et al., 2000) A brief review


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