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Recent CTM work in Leeds and Modelling for SCOUT IP Martyn Chipperfield University of Leeds, Leeds, U.K. SLIMCAT/TOMCAT off-line 3D Global CTM - Recent work at Leeds Modelling in SCOUT-O3 Integrated FP6 Project (IP) Potential links with ACCENT. TOMCAT + SLIMCAT 3D CTM.
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Recent CTM work in Leeds and Modelling for SCOUT IP Martyn Chipperfield University of Leeds, Leeds, U.K. • SLIMCAT/TOMCAT off-line 3D Global CTM • - Recent work at Leeds • Modelling in SCOUT-O3 Integrated FP6 Project (IP) • Potential links with ACCENT
TOMCAT + SLIMCAT 3D CTM • Off-line 3-D chemical transport model • Vertical coordinate (-p, -). Variable resolution. • Horizontal winds and temperatures specified from analyses (e.g. ECMWF). • Vertical winds from analysed divergence or • diagnosed heating rates (in stratosphere). • Advection: Prather [1986] second-order moments or • semi-Lagrangian. • Trajectories (4th order Runge Kutta embedded in model) • Physics: Tiedtke [1989] convection scheme. • Holtslag and Boville [1993] or Louis [1979] PBL schemes. • Chemistry: • Stratosphere: Ox, NOy, HOx, Cly, Bry, CHOx, source gases. Aerosols/PSCs.. • Troposphere: Ox, NOy, HOx C1-C3. Wet/dry deposition. Emissions etc… • Aerosols: • Troposphere: Sulphate, sea-salt, (SOA) (GLOMAP) • Stratosphere: Denitrification microphysical model (DLAPSE)
Development of TOMCAT/SLIMCAT -level version of TOMCAT SLIMCAT Trajectories TOMCAT Trop/Strat CTM Aerosol c1991 c1995 pTOMCAT (UCAM) Current model
Vertical Coordinate Advantage for STE calculations? ‘SLIMCAT’ mode hybrid - ‘TOMCAT’ mode hybrid -p Lowest pure level = 350 K typically Surface
SLIMCAT/TOMCAT CTM STRATOSPHERIC AGE OF AIR (Perpetual 1992) -p levels Large difference in age from same model with different: Vertical coordinate Vertical transport Advection scheme - levels -p levels Heating rates SL advection ECMWF ER40
SLIMCAT Age of air versus ER-2/balloon observations Heating rates older than divergence - older than -p
SCOUT-O3 Integrated Project Stratospheric-Climate Links with Emphasis on the UTLS Coordinator: J.A. Pyle (UCam) ~65 Partners 5 years Start: 1/5/2004 Goal: “Forecasts of the stratospheric coupled chemistry/climate system and impact on atmospheric ozone and surface UV”
Activity 6: CTMs in SCOUT-O3 Also other CTMs: REPROBUS (CNRS, integrated in Activity 2) UCI Irvine (USA)
SCOUT Activity 5: Chemistry + Particles Crowley (MPIC) and Larsen (DMI) 5.1 NOx and NOy in the UTLS (kinetics of OH + HNO3, HO2NO2, RO2 + NO, heterogeneous processes). 5.2 Organics + HOx in the UT (OH + alkenes kinetics, carbonyls + hv, CH3O2 + HO2 ice interactions) 5.3 UT-ice: Nucleation, occurrence, persistence and optical properties (cirrus) New kinetic data to evaluate/implement
SCOUT Activity 2: Tropical $$! Schiller (FZJ), Pommereau (CNRS) and Peter (ETH) 2.1-2.5 Tropical aircraft/balloon campaign. To understand composition of air entering stratosphere and transport to and through the TTL (tropical tropopause layer) 2.6 Tropical modelling (global and mesoscale) CTM questions, e.g.: Formulation (e.g. vertical velocity) Resolved v parameterised transport Do models capture observed features of TTL Lagrangian v Eulerian
SCOUT Activity 3: Extra-tropical O3 and H2O Haynes (UCAM) and Rex (AWI) 3.1 ‘Age tracer’ observations and long-term (stratospheric modelling). ( will improve stratospheric upper boundary) 3.2 Extra-tropical tropopause region (inc. KNMI, UCAM UIO) ( potentially strong links with ACCENT) 3.3 Polar Ozone
SCOUT Activity 1: O3 climate and UV predictions Dameris (DLR) and Langematz (FUB) 1.1 Validation and intercomparison Testing existing simulations. Tests developed during CCM 2003 workshop (web page). Workshop later this year?? 1.2 Model development 1.3 Scenarios 1.4 Simulations 1.5 Protocols 1.6 Particles 1.7 Coupled modes 1.8 Detection 1.9 Tropical analyses
Trajectory Calculations • The CTM can also calculate 3D particle/air mass trajectories • 4th order Runge Kutte time integration. • In TOMCAT mode vertical motion from analysed winds (divergence) or isobaric. • In SLIMCAT model vertical motion from heating rates (MIDRAD, CCM) or isentropic.
Stratospheric Chemical Scheme 100 gas-phase reactions 20 photolysis reactions xx heterogeneous reactions on liquid sulphate aerosols and solid polar stratospheric clouds (PSCs).
Schematic of Chemical Transport Model (CTM) Off-Line 3D Global Chemical Transport Model Meteorological analyses e.g. ECMWF, UKMO, GEOS Physics Advection Convection etc Detailed chemistry schemes Stratospheric Tropospheric Resolution? Vertical coordinate? Vertical transport? Assimilation Chemical Observations Could be (should be) similar in CCMs and CTMs
Activity 6: CTMs in SCOUT Also other CTMs: REPROBUS (CNRS, integrated in Activity 2) UCI Irvine (USA)
Central Role of CTMs in SCOUT Activity 5 Lab. Studies Activity 1 CCMs Laboratory photochemical data Model code/parameterisations Model results Activity 6 CTM Campaign planning Data interpretation Data interpretation Link to large-scale/long-term Activity 2 Tropics Activity 3 Extratropics A major linking activity
Contribution to Activity 2: Tropics WP 2.6 Tropical Modelling Planning
Main CTM effort in months 1-18 Contribution to Activity 3: Extratropics WP 3.1 Extratropical Stratosphere
Contribution to Activity 3: Extratropics WP 3.2 Extratropical Tropopause Region (* also Haynes/Law – CNRS CTM)