www.dlr.de Chart 1 Routing options to reduce aviation s climate impact Volker Grewe DLR-Institut für Physik der Atmosphäre & Chair for Climate Effects of Aviation, TU Delft Aerospace Engineering
www.dlr.de Chart 2 Atmospheric effects of aviation Emissions CO 2 H 2 O NO x VOC SO 2 Particles Changes in atmospheric composition CO 2 H 2 O CH 4 O 3 Particles Clouds Contrails Climate forcings Direct greenhouse gases Indirect greenhouse gases Direct aerosol effect Clouds
Radiative forcing from aviation 2005, updated by recent DLR results T surf = RF 3Sausen & Grewe @ BDL 2016 17.04.2016 recent DLR results Note: Different bases years and different emission data have been used
What can we do about the uncertainty? An example from aviation: 4 slightly different emissions scenarios Perform Monte-Carlo simulations: pdf of ATR Sausen & Grewe @ BDL 2016 Dahlmann et al., 2016 4 17.04.2016
What can we do about the uncertainty? An example from aviation: 4 slightly different emissions scenarios Perform Monte-Carlo simulations: pdf of ATR Sausen & Grewe @ BDL 2016 Dahlmann et al., 2016 5 17.04.2016
www.dlr.de Chart 6 Routing Options Standard flight trajectory PhD of Koch (2014) and Dahlmann (2012) CATS: Lower flight altitude and reduced speed ISO: Intermediate Stop Operations Climate sensitive REACT4C/WeCare: Climate friendly routing Grewe et al. (2014a,b) PhD of F. Linke (2016) Interdisciplinary work: Aircraft design Flight routing Atmospheric science
www.dlr.de Chart 7 DLR-Project CATS: Climate Compatible Air Transport System Focus on a long-range aircraft =AirClim Koch et al., 2011
www.dlr.de Chart 8 CATS optimisation approach Variation of initial cruise altitude and speed Optimal relation between costs and climate Definition of new design point Optimisation of the new aircraft for this new design point Koch, 2013
www.dlr.de Chart 9 A330: Potential of a climate change reduction: CATS-results Variation in speed an cruise altitude 30% Reduction in climate change with 5% increase in costs 64% Reduction in climate change with 32% increase in costs (w/o adaption of aircraft) (Dahlmann, 2012) (Koch et al., 2011)
www.dlr.de Chart 10 CATS Final results Cumulative potential for all routes operated by redesigned A/C Max Mach 0.775 / Max Altitude 10500m Redesigned A/C considerably improves climate impact mitigation potential and cost penalty Koch (2012)
www.dlr.de Chart 11 Climate optimized routing by using climate cost functions Climate cost functions: = Measure for climate impact of individual aviation emissions depending on emission location, emission altitude, and local emission time Depending on weather situation Aviation impacts investigated: Ozone, Methane + primary mode ozone, Contrails, Water vapour, CO 2 Climate cost function is given as number with units Kelvin per kg emission Grewe et al., 2014a,b
www.dlr.de Chart 12 Climate optimized routing by using climate change functions Climate change functions: = Measure for climate impact of individual aviation emissions depending on emission location, emission altitude, and local emission time Depending on weather situation Aviation impacts investigated: Ozone, Methane + primary mode ozone, Contrails, Water vapour, CO 2 Climate cost function is given as number with units Kelvin per kg emission Grewe et al., 2014a,b
www.dlr.de Chart 13 Evolution of aircraft NO x at two different locations A B What happens if an aircraft emits NO x at location A compared to location B? Frömming et al., 2011
www.dlr.de Chart 14 Evolution of O 3 [ppt] following a NO x pulse A: 250hPa, 40 N, 60 W, 12 UTC B: 250hPa, 40 N, 30 W, 12 UTC Pressure [hpa] Change in NO x and Ozone mass EMAC Symposium 14. 16. Februar 2012
www.dlr.de Chart 15 Weather situation at cruise levels Strong jet stream, basically in West-East direction Geopotential heights Wind velocity Low 65 m/s Jet stream 65 m/s = 230 km/h = 120 kn Grewe et al., 2014b
www.dlr.de Chart 16 Climate cost functions at 200 hpa for 12:00 UTC Contrail-Cirrus Ozone Contrails complex: Depending on - Lifetime - Solar angle day/night - Transport - Loss processes Methane Total NO x Chemistry: Ozone / NOx pattern - Follows meteorology - Jet: Large values - Low pressure: Smaller values Grewe et al., Atmos. Environm., 2014b
www.dlr.de Chart 17 Air Traffic One day ~800 flights between USA and Real air traffic taken into account Europe Flight simulations performed by Eurocontrol Optimisation: Costs: Fuel and Crew Climate with different metrics
www.dlr.de Chart 18 Relation between costs and climate: Pareto front Climate optimal solution at higher costs Large potential for climate impact reduction (25%) at low costs (0.5%) Grewe et al., 2014b
www.dlr.de Chart 19 Relation between costs and climate: Pareto front Eastbound traffic has less climate reduction potential, because it is more bound to the jet stream: Leaving the jet stream leads to fuel and NO x penalties Grewe et al., 2014b
www.dlr.de Chart 20 How is the air traffic modified? Changes along the Pareto-Front 0% Grewe et al., 2014b
www.dlr.de Chart 21 How is the air traffic modified? Changes along the Pareto-Front 25% Only small changes in flight altitude Grewe et al., 2014b
www.dlr.de Chart 22 How is the air traffic modified? Changes along the Pareto-Front 50% Some flights are shifted to lower flight altitudes Grewe et al., 2014b
www.dlr.de Chart 23 How is the air traffic modified? Changes along the Pareto-Front 75% Many flights shifted from FL380 to FL300 Grewe et al., 2014b
www.dlr.de Chart 24 How is the air traffic modified? Changes along the Pareto-Front 100% Main flight altitude: FL 300 Grewe et al., 2014b
www.dlr.de Chart 25 Horizontal re-routing is effective Courtesy: DKRZ
www.dlr.de Chart 26 > Lecture > Author Document > Date Is closing of airspace an option to achieve routings with a reduction in the impact on climate? Sensitivity study One route Potentially yes! Pareto front for airspace closing Pareto front for optimal trajectories Niklaß et al., 2015
www.dlr.de Chart 27 > TAC 4 Conference, Bad Kohlgrub> Volker Grewe > 23 June 2015 Intermediate Stop Operations (ISO) Refuelling implies: Lower weight / Re-routing / different altitude Re-routing options for one route Flight profiles Fuel reduction [%] Tradeoffs between temperature changes from CO 2 reduction and O 3 /H 2 O increase Linke, 2016; Linke et al., 2016
www.dlr.de Chart 28 > Lecture > Author Document > Date Outlook / Open Questions addressed in WeCare and ATM4E What is the cost-effects realtion for full 3D trajectory optimisations impact on ATC work load? impact on ATM, especially in Europe (higher air traffic density)? impact of uncertainties from atmospheric science on the results? impact of weather forecast on optimal routing? Can we verify the results of climate optimal routing? Air traffic simulator within a Earth-System Model (Yamashita et al. 2016)
www.dlr.de Chart 29 > Lecture > Author Document > Date Summary Aviation has an impact on climate and routing is an important factor. Atmospheric uncertainties has to be key part of climate impact assessment We are moving from suggesting options to quantifying options Different options have different requirements, different type of costs, different time scales and effectiveness Difficult to compare Political framework required to enable climate impact reduction Grewe&Linke, submitted, 2016
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