Routing options to reduce aviation’s climate impact

Routing options to reduce aviation’s climate impact

Grewe, Volker

Publication date 2016

Document Version Final published version

Citation (APA)

Grewe, V. (2016). Routing options to reduce aviation’s climate impact. International Workshop on Aviation and Climate Change, Toronto, Canada.

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This work is downloaded from Delft University of Technology.

Volker Grewe

DLR-Institut für Physik der Atmosphäre

&

Chair for Climate Effects of Aviation,

TU Delft Aerospace Engineering

International Workshop on Aviation and Climate Change, 18.-20. Mai 2016, Toronto, Canada

Atmospheric effects of aviation

updated by recent DLR results

T

_surf

=

 · RF

Different bases years and different emission data have been used

An example from aviation: 4 slightly different emissions scenarios

Perform Monte-Carlo simulations: pdf of ATR

An example from aviation: 4 slightly different emissions scenarios

Perform Monte-Carlo simulations: pdf of ATR

Climate sensitive

Routing Options

Standard flight trajectory

CATS: Lower flight altitude and reduced speed ISO: Intermediate Stop Operations REACT4C/WeCare: Climate friendly routing PhD of Koch (2014) and Dahlmann (2012) PhD of F. Linke (2016) Grewe et al. (2014a,b)

Interdisciplinary work:

DLR-Project CATS:

Climate Compatible Air Transport System

Focus on a long-range aircraft

=AirClim

• 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

CATS‐optimisation approach

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)

Cumulative potential for all routes operated by redesigned A/C

CATS Final results

Climate optimized routing by using climate cost functions

Climate cost function is given as number with units

Kelvin per kg emission

Grewe et al., 2014a,b 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:

Climate optimized routing by using climate

change

functions

Climate cost function is given as number with units

Kelvin per kg emission

Grewe et al., 2014a,b 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:

A B

What happens if an aircraft emits 

NO

at location A compared to location B?

Evolution of aircraft NO

at two different locations

EMAC‐Symposium 14.‐16. Februar 2012

Evolution of O

[ppt] following a NO

pulse

A: 250hPa, 40°N, 60°W, 12 UTC

B: 250hPa, 40°N, 30°W, 12 UTC

Weather situation at cruise levels

Strong jet stream, basically in West-East direction

Low

Jet stream

65 m/s

65 m/s = 230 km/h = 120 kn

Geopotential heights Wind velocity

Climate cost functions at 200 hPa for 12:00 UTC

Contrails complex: Depending on

- Lifetime

- Solar angle day/night - Transport

- Loss processes

Chemistry:

Ozone / NOx pattern - Follows meteorology - Jet: Large values - Low pressure:

Smaller values

Contrail-Cirrus

Ozone

Methane

Total NO

Air Traffic

•

One day

• ~800 flights between USA and

Europe

• Real air traffic taken into account

• Flight simulations performed by

Eurocontrol

• Optimisation:

• Costs: Fuel and Crew

Relation between costs and climate: Pareto front

Large potential for climate impact reduction (25%) at low costs (0.5%) Climate optimal solution at higher costs Grewe et al., 2014b

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

How is the air traffic modified?

Changes along the Pareto-Front

0%

How is the air traffic modified?

Changes along the Pareto-Front

25%

Only small changes in flight altitude

How is the air traffic modified?

Changes along the Pareto-Front

50%

Some flights are shifted to lower flight altitudes

How is the air traffic modified?

Changes along the Pareto-Front

75%

Many flights shifted from FL380 to FL300

How is the air traffic modified?

Changes along the Pareto-Front

100%

Main flight altitude: FL 300

Horizontal re-routing is effective

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

Intermediate Stop Operations (ISO)

Refuelling implies: Lower weight / Re-routing / different altitude Re-routing options for one route

Fuel reduction [%]

Flight profiles

Tradeoffs between

temperature changes from CO₂ reduction and O₃/H₂O

Outlook /

Open Questions addressed in WeCare and ATM4E

• 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?

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

Thank you for your 

attention

Thank you for your 

attention

Thank you for your 

attention

Thank you for your 

attention