UTLS Chemistry and Transport Issues in WACCM Doug Kinnison START 2008 Meeting 8 January Doug Kinnison START 2008 Meeting 8 January Outline Motivation from a 3D modeling point of view. Brief Description of Global modeling framework at NCAR. Influence of Tropospheric Chemistry on UTLS region. Chemical Discontinuity at the Extratropical Thermal Tropopause. Very Short-Live Substance (e.g., halogenated species) Motivation for Participation in START08 and other aircraft campaigns. Diagnose the importance of the following model components on the chemical distribution in the UTLS. Meteorological Fields Fully interactive Chemistry-Climate Models, versus Data assimilation met fields used with CTMs Transport processes Accuracy of advection and convection routines Resolution Horizontal Vertical Chemical mechanism Middle Atmospheric (MA) mechanism Whole Atmosphere: MA + detailed troposphere chemistry Modeling Framework at NCAR for use in START08 + NCAR Community Climate System Model Atmosphere CAM3 (WACCM3) OceanSea Ice Land NCAR Community Climate System Model Atmosphere CAM3 (WACCM3) GEOS-5 Met. Fields (U, V, T, etc). Advantage: Allows direct comparisons with observations. Allow direct comparisons with Lagrangian model(s) using the same meteorological fields. CCMs represents chemical, dynamical, and physical processes from the surface to 140 km 2.8 x 2.8 MLT; 3-5 km Res. Stratosphere; 1-2 km Res. UTLS; 1 km Res. WACCM3 Model Description MODEL Framework Meteorological Fields Tracer Advection ResolutionChemistry WACCM3 Extension the Community Atmospheric Model, Version 3 (CAM3) Fully- interactive, i.e., dynamics consistent with model derived : O 3, CO 2, CH 4, N 2 O, H 2 O, CFC- 11, CFC-12, O 2, NO Analyzed Met Fields (e.g., GEOS-5) Flux Form Finite Volume (Lin, 2004) 1.9 x 2.5 , horizontal 66 levels (0-150 km) TTL version has 103 levels. Approx 400m in UTLS Anal. Met. Defines vertical res. Two Mechanisms 57 species mechanism includes the necessary Ox, HOx, NOx, BrOx, and ClOx species for the Middle Atmosphere (MA). 115 species mechanism includes the MA + NMHCs. Heterogeneous Chemistry on STS, NAT, ICE Middle Atmosphere Mechanism (57 species; 148 Gas-phase; 17 Heterogeneous; 47 Photolytic) Long-lived Species: (19-species) Misc:CO 2, CO, CH 4, H 2 O, N 2 O, H 2, O 2 CFCs: CCl 4, CFC-11, CFC-12, CFC-113 HCFCs: HCFC-22 Chlorocarbons:CH 3 Cl, CH 3 CCl 3, Bromocarbons: CH 3 Br Halons: H-1211, H-1301 Constant Species:M, N 2 Short-lived Species: (38-species) O X : O 3, O, O( 1 D) NO X :N, N ( 2 D), NO, NO 2, NO 3, N 2 O 5, HNO 3, HO 2 NO 2 ClO X :Cl, ClO, Cl 2 O 2, OClO, HOCl, HCl, ClONO 2, Cl 2 BrO X :Br, BrO, HOBr, HBr, BrCl, BrONO 2 HO X :H, OH, HO 2, H 2 O 2 HC Species:CH 2 O, CH 3 O 2, CH 3 OOH Ions: N +, N 2 +, NO +, O +, O 2 + Radiatively Active Whole Atmosphere Mechanism (115 species; 287 Gas-phase; 17 Heterogeneous; 72 photolytic) Additional Surface Source Gases (14 additional) NHMCs:CH 3 OH, C 2 H 6, C 2 H 4, C 2 H 5 OH, CH 3 CHO C 3 H 8, C 3 H 6, CH 3 COCH 3 (Acetone) C 4 H 8 (BIGENE), C 4 H 8 O (MEK) C 5 H 8 (Isoprene), C 5 H 12 (BIGALK) C 7 H 8 (Toluene) C 10 H 16 (Terpenes) Radicals:Approx. 44 additional species. Includes:Detailed 3D (lat/lon/time) emission inventories of natural and anthropogenic surface sources Dry and wet deposition of soluble species Lightning and Aircraft production of NOx StudyReference Stratospheric T, H 2 O, O 3 trendsGarcia et al., JGR, 112, D09301, A set of diagnostics for evaluating chemistry-climate models in the extratropical tropopause region. Pan et al., JGR, 112, D09316, The global impact of supersaturation in a coupled chemistry-climate model Gettelman and Kinnison, ACP, 7, , st Ozone RecoveryEyring et al., JGR, 112, D16303, Chemistry introduction.Kinnison et al., JGR, 112, D20302, Solar variability.Marsh et al., JGR, 112, D23306, Evaluation of stratospheric polar processes. Tilmes et al., JGR, 112, D24301, Selected Publications Influence of Tropospheric Chemistry on the UTLS Tropospheric and UTLS Representation of Ozone: 20 N 40 N Red = 115 Species sim. Blue = 57 Species sim. Black = Ozonesonde (Logan, 1999). Representation of CO at the Surface. Red = 115 Species sim. Blue = 57 Species sim. Black = NOAA Surface Stations 82 N71 N 44 N53 N 32 N8 S Tropospheric representation of CO. Red = 115 Species sim. Blue = 57 Species sim. Black = Aircraft Missions SONEX: Oct/Nov TOPSE: Feb-May TRACE A: Sep./Oct TRACE P: Mar/Apr VOTE: Jan/Feb Emmons et al., JGR, 2000. Comparison of WACCM3 115 and 57 simulations ColO 3 Chemical Discontinuity at the Extratropical Thermal Tropopause Chemical Discontinuity at the Thermal Tropopause, Pan et al., JGR This approach facilitates comparison between observations made under different meteorological conditions and models. 65N *** POLARIS data only! Ozone CO Sharp transition at the tropospause for both Ozone and CO O 3 abundance in the troposphere is LS is similar in both the WA3 115 and 57 species mechanism. Very Short-Live Substance (VSLS) ( 0.5 years) Very Short-lived Substances (VSLS) SG = Organic VSL Source Gas PG = VSL Product gas Xy VSLS = inorganic halogens from organic SG degradation. TC4, Whole Air Sampler, Schauffler, Atlas, et al., AGU, 2007 Flt km Bromofor m pptv pptv 10 km Convection lofting VSLS into the TTL. Influencing the Total Inorganic Bromine abundance. Transported to ExTL? Org. BrOy Halogenated Very Short-lived Substances (VSLS) currently being added the WA3 UTLS mechanism Source GasFormula Local Lifetime (days) Main Loss processes WAS BromochloromethaneCH 2 BrCl150OH Trichloromethane (chloroform) CHCl 3 150OH Methylene chlorideCH 2 Cl 2 140OH DibromomethaneCH 2 Br 2 120OH BromodichloromethaneCHBrCl 2 78OH, hv DibromochloromethaneCHBr 2 Cl69hv, OH Tribromomethane (bromoform) CHBr 3 26hv Methyl iodideCH 3 I7hv TrifluoroiodomethaneCF 3 I4hv? Summary WACCM3 simulations will support START08: Detailed stratospheric and tropospheric chemistry, plus VSLS. Higher horizontal resolution version will be used (2 ). Will be driven with GMAO GEOS-5 analyzed meteorological fields. Comparison of chemical constituents and mixing processes with Lagrangian model(s) will be made. Climatological simulations (fully interactive) can be run at higher vertical resolution (400m). Model results will be made available to START08 team. Examination of Halogenated VSLS will help evaluate the dynamics and transport characteristics of the CCM. Diagnostics will be created and made available to the CCM community (see Tilmes and Gettelman pres.) The End