Measurements of NO2 shipping emissions using optical remote

Measurements of NO2 shipping emissions using optical remote

Measurements of NO2
shipping emissions with an imaging
DOAS instrument: AirMAP
First results from the NOSE campaign
and measurements in Wedel
Andreas Meier1, Anja Schönhardt1, Andreas Richter1, André Seyler1, Thomas Ruhtz2,
Carsten Lindemann2, John P. Burrows1
1Institut
für Umweltphysik, Universität Bremen
2Institut für Weltraumwissenschaften, FU Berlin
EO 4 Ocean Atmosphere Interactions 2014, Frascati, 18.03.2014
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Outline
• Why airborne measurements of NO2 ?
• Instrumental setup
• NO2 – airborne measurements around
Neuwerk
• NO2 – ground-based measurements in Wedel
• Summary & Outlook
2
Why measure NO2?
• Emissions of NOx (NO + NO2) have high impact
on tropospheric chemistry
– Oxidizing capacity of troposphere trough cycles
with (hydr)oxy-radicals, VOCs, Ozone
– O3-Level
– Acid rain (HNO3)
• Harmful effects on health and environment
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Why shipping emissions?
Estimations for sector [Tg N / yr]
Global NOx emissions
in 2000
(Denman et al. 2007, IPCC)
Global NOx emissions
from ocean shipping
(Corbett and Köhler 2003)
Fraction of ocean
shipping
51.9
6.9
13 %
Source: http://unctadstat.unctad.org
Capacity of global merchant fleet has
doubled since 2000
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Why airborne measurements?
• Satellite remote sensing
– Global long-term coverage
– But poor spatial resolution cannot well resolve emission on small
scales
• Ground-based remote sensing + in-situ
– High sensitivity
– Profile information
– Limited spatial coverage (fixed location)
• Airborne imaging DOAS
– Fills the gap between ground-based and satellite measurements
– Good spatial coverage at a fine spatial resolution
– Facilitates separation of NOx sources close together
Especially important in polluted areas like coastal regions
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Instrumental setup
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Viewing geometry
q
qi
g
s
w
H
v
texp
opening angle/FOV across track ~ 48°
individual viewing angle of direction i (max. 35, typ. 9)
opening angle/FOV along track ~ 1.5°
side length of pixel across track
side length of pixel along track
flight altitude ~ 1400m
aircraft speed (typ. 60m/s)
exposure time typ. 0.5s
Ground pixel size
VD = 9 (typ.)
VD= 35 (max)
130 x 30 m
36 x 30 m
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Airplane and instrument
Cessna 207 Turbo
Operated by FU Berlin
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Neuwerk flight pattern
Neuwerk
21.08.13, 9:00 – 12:30 UTC
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Overview Neuwerk
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Shipping lane Neuwerk 0° N
9:34 + 2min
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Shipping lane Neuwerk 0° S
9:41 + 2min
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Individual ship “MOL”
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“MOL” at overflight
Image from AirMAP scene camera
Name:
Length:
Width:
Power:
MOL Continuity
320 m
46 m
66962 kW
Flight
direction
MOL Continuity
From MarineTraffic.com
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Plume of “MOL”
3.6 km
Ship „MOL“
Alt. 800 m
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Wedel (ground based)
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Measurement site Wedel
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Single ship emission events NO2
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Single ship emission events NO2
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Single ship emission events NO2
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Summary & Conclusions
• Instrument operated successfully
• Shipping emissions can be observed
• Measurements can contribute to better
understanding of plume evolution and
NO -> NO2 conversion
• Further investigations needed
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Thank you for listening
Acknowledgements
• Supervision and support
–
–
–
–
Anja Schönhardt
Andreas Richter
DOAS Group, IUP-UB
John.P. Burrows
• Campaign support
– FU Berlin: Thomas Ruhtz, Carsten Lindemann
• Financial support
– University of Bremen, John.P. Burrows , Heinrich
Bovensmann
– MeSmart project, Folkard Wittrock
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Outlook
• Assignment of measured NO2 to emission
sources
– Meteorological data
• Estimation of NOx source strength
– AIS ship data + ship database
• Position
• Speed
• Ship type , engine
=> ship’s track
=> load of engine
=> power
– Comparison with MAX-DOAS on Neuwerk
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DOAS data analysis
Parameter
Value
Spectral calibration
Using Fraunhofer lines
Fitting window
425 – 450 nm
Trace gases
NO2 (293K), O3 (241K), O4 (296K), H2O
(HITRAN2006)
Atmospheric Effects
Ring effect (SCIATRAN calculation),
constant stray light
Polynomial
Quadratic
Reference spectrum I0
Rural scene with low NO2
Slit function
Individual per viewing direction
AMF
Const. albedo, no aerosols
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