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H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
1
Measuring Atmospheric Humidityfrom Commercial Aircraft:
Insights from MOZAIC and IAGOSHerman G. J. Smit ([email protected])
Forschungszentrum Juelich (ICG-2)
H 2 O -S e n s o r
A I R C R A F TS K I N
S E N S O R SR H : H U M I C A P - HT : P T 1 0 0
D E I C IN GH E A T E R
B O U N D A R Y L A Y E R SC O N T R O L H O L E S
R IG H T A N G L EP R O D U C E SP A R T I C L E
S E P A R A T I O N
Past and Present: MOZAIC
HumiditySampling
Quality Assurance & Synergy of Data
Future:IAGOS
Ice
Liquid
0
2
4
6
8
10
Pro
babi
lity
[%]
0 25 50 75 100 125 150 175Relative Humidity [%]
40N-60N
Ice
Liquid
0
2
4
6
8
10
Pro
babi
lity
[%]
0 25 50 75 100 125 150 175Relative Humidity [%]
40N-60N
Ice
Liquid
0
2
4
6
8
10
Pro
babi
lity
[%]
0 25 50 75 100 125 150 175Relative Humidity [%]
40N-60N
MOZAIC
Ice
Liquid
0
2
4
6
8
10
Pro
babi
lity
[%]
0 25 50 75 100 125 150 175Relative Humidity [%]
40N-60N
Ice
Liquid
0
2
4
6
8
10
Pro
babi
lity
[%]
0 25 50 75 100 125 150 175Relative Humidity [%]
40N-60N
Ice
Liquid
0
2
4
6
8
10
Pro
babi
lity
[%]
0 25 50 75 100 125 150 175Relative Humidity [%]
40N-60N
MOZAIC
-60 -40 -20 0 20Static Air Temperature
0
2
4
6
8
10
Abs
.Err
or o
f Rel.H
umi.
[% R
H]
12 9 6 3 0
Altitude [km]
All Data 1999/2000
In: Helten et al., J.Geophys.Res., 1998
-60 -40 -20 0 20Static Air Temperature
0
2
4
6
8
10
Abs
.Err
or o
f Rel.H
umi.
[% R
H]
12 9 6 3 0
Altitude [km]
All Data 1999/2000
In: Helten et al., J.Geophys.Res., 1998
-60 -40 -20 0 20Static Air Temperature
0
2
4
6
8
10
Abs
.Err
or o
f Rel.H
umi.
[% R
H]
12 9 6 3 0
Altitude [km]
All Data 1999/2000
In: Helten et al., J.Geophys.Res., 1998
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
2
Doubling CO2-concentration: 2-5oC Temperature increase1/3-part: direct via CO22/3-part: via positive feedback of water vapor+clouds
Wat
erV
apor
Mas
s(r
elat
ive
to p
re-in
dust
rialv
alue
)
Change in Global MeanWater Vapor (NOAA/GDFL-GCM ScenarioRun)
P≈200 hPa
P≈900 hPa
Wat
erV
apor
Mas
s(r
elat
ive
to p
re-in
dust
rialv
alue
)
Change in Global MeanWater Vapor (NOAA/GDFL-GCM ScenarioRun)
P≈200 hPa
P≈900 hPa
(WV)
Wat
er
Vapo
r
(C) C
loud
(LR
) La
pse
Rat
e
WV+
LR
(A)
Alb
edo ALL
FeedbackType
Feed
back
Str
engt
h(W
m-2
K-1
-1
0
1
2
(WV)
Wat
er
Vapo
r
(C) C
loud
(LR
) La
pse
Rat
e
WV+
LR
(A)
Alb
edo ALL
FeedbackType
(C) C
loud
(LR
) La
pse
Rat
e
WV+
LR
(A)
Alb
edo ALL
FeedbackType
FeedbackType
Feed
back
Str
engt
h(W
m-2
K-1
-1
0
1
2
Feed
back
Str
engt
h(W
m-2
K-1
-1
0
1
2
Most Prominent Climate Feedbacks
(WV)
Wat
er
Vapo
r
(C) C
loud
(LR
) La
pse
Rat
e
WV+
LR
(A)
Alb
edo ALL
FeedbackType
Feed
back
Str
engt
h(W
m-2
K-1
-1
0
1
2
(WV)
Wat
er
Vapo
r
(C) C
loud
(LR
) La
pse
Rat
e
WV+
LR
(A)
Alb
edo ALL
FeedbackType
(C) C
loud
(LR
) La
pse
Rat
e
WV+
LR
(A)
Alb
edo ALL
FeedbackType
FeedbackType
Feed
back
Str
engt
h(W
m-2
K-1
-1
0
1
2
Feed
back
Str
engt
h(W
m-2
K-1
-1
0
1
2
Most Prominent Climate Feedbacks
Upper troposphere most sensitive region in climate change
Why Monitoring Humidity in Upper Troposphere ??
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
3
MOZAIC - OperationPartners: CNRS, FZJ, CNRM, UCAM, Lufthansa, AIRBUS
LIMA
SAN FRANCISCO
LOS ANGELES NEW ORLEANS
MEXICO
DALLAS
BOSTON
HOUSTON
CINCINNATI
MIAMI
CHICAGO
ANTIGUASAN DOMINGO
ATLANTA
CARACAS
SANTIAGO
MONTREAL
PLATA PUERTOPUERTO RICO
QUAYAQUIL
TORONTO
QUITO
WASHINGTON
BOGOTA
NEW YORK
SAINT MARTINPOINTE A PITRE
CAYENNE
BUENOS AIRES
MONTEVIDEO
DAKAR
SAO PAULO RIO
RECIFE
BANJOUL
ABIDJAN
LONDON
COTONOU
BRUXELLES
PARIS
LAGOS
AMSTERDAM
FRANKFURTVIENNA
LIBREVILLE
DOUALAYAOUNDE
LUANDABRAZZAVILLE
WINDHOEK
ATHENES
HERAKLION
JOHANNESBURG
ISTANBUL
ANTALYA
KIGALIENTEBBE
ANKARA
TEL AVIV
NAIROBI
ANTANANARIVO
TEHERAN
DUBAI
MUMBAI
MALE
DELHI
COLOMBOMADRAS
BANGKOK
HANOI
SINGAPORE
JAKARTA
SAIGON
BEIJING
SHANGAI
SEOUL
OSAKANAGOYA
TOKYO
>20000 flights since 1994
Instruments deployed on five Airbus A340 aircraft operated by European airlines: DLH (2), AF, AUA, AN2500 longhaul flights per year (5000 vertical profiles)> 20 000 flights since 1994 for O3 and H2OCO and NOy since 2001
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
4
From a research project to sustainable Earth observations
In-Service Aircraft for a Global Observing System
Coordination: Andreas Volz-Thomas ([email protected]://www.fz-juelich.de/icg/icg-2/iagos
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
5
MOZAIC: Humidity Sampling
H 2O -Sen sor
AIRCRAFTSKIN
SENSORSRH: HUMICAP-HT : PT100
DEICINGHEATER
BOUNDARY LAYERSCONTROL HOLES
RIGHT ANGLEPRODUCESPARTICLE
SEPARATION
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
6
SAT
TAT
0
5
10
15
Adia
batic
Fac
tor R
HS
/RH
D
0 2 4 6 8 10 12 14
Altitude [km]
-60
-40
-20
0
20
Tem
pera
ture
[°C
] RHS/RHD
MOZAIC: Humidity Sensor in Rosemount Air Inlet System
H 2 O -S e n s o r
AIRCRAFTSKIN
SENSORSRH: HUMICAP-HT : PT100
DEICINGHEATER
BOUNDARY LAYERSCONTROL HOLES
RIGHT ANGLEPRODUCESPARTICLE
SEPARATION
TAT, RHD
SAT
RHS
Rosemount HousingTotal TemperatureModel 102 BX
In inlet speed reduction (Mach≈0.8 to 0) with adiabaticconversion: ► Heating (SAT to TAT) : in UT ≈ 30oC
► Compression (PS to PD): in UT ≈ Factor 1.6RH at detector (RHD) << RH sampled air (RHS)
► At cruise altitude RHS ≈ 13 x RHD
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
7
MOZAIC-Humidity: Pre-&Post Flight Calibration
♦ Regular calibration (every 500 flight hours)♦ In environmental simulation chamber♦ Against Lyman(α)-fluorescence hygrometer♦ Under realistic flight conditions of humidity,
temperature and pressure
♦ Evaluation of two year record of pre-and post-flight calibrations
♦ Results agree well with in-flightintercomparisons
[Helten et al. Geophys.Res.1998, 1999]
-60 -40 -20 0 20Static Air Temperature
0
2
4
6
8
10
Abs
.Err
or o
f Rel
.Hum
i. [%
RH
]
12 9 6 3 0
Altitude [km]
All Data 1999/2000
In: Helten et al., J.Geophys.Res., 1998
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
8
MOZAIC Relative Humidity in Upper Troposphere (UT) over Atlantic
• MOZAIC provided the firstclimatology of humidity in the UT
• Large variability in time and space
-20
0
20
40
60La
titud
e
5102030405060708090100
Jan
95
Jan
96
Jan
97
Jan
98
Jan
99
Jan
00
• More than 30% of UTH-dataare Ice Super Saturated (ISS)
• But less than 0.5-1% of dataare Saturated to Liquid
%
Control of Humidity in UT??Long Term Changes ??
Ice
Liquid
0
2
4
6
8
10
Pro
bab i
li ty
[ %]
0 25 50 75 100 125 150 175Relative Humidity [%]
40N-60N
Ice
Liquid
0
2
4
6
8
10
Pro
bab i
li ty
[ %]
0 25 50 75 100 125 150 175Relative Humidity [%]
40N-60N
Ice
Liquid
0
2
4
6
8
10
Pro
bab i
li ty
[ %]
0 25 50 75 100 125 150 175Relative Humidity [%]
40N-60N
Ice
Liquid
0
2
4
6
8
10
Pro
bab i
li ty
[ %]
0 25 50 75 100 125 150 175Relative Humidity [%]
40N-60N
Ice
Liquid
0
2
4
6
8
10
Pro
bab i
li ty
[ %]
0 25 50 75 100 125 150 175Relative Humidity [%]
40N-60N
Ice
Liquid
0
2
4
6
8
10
Pro
bab i
li ty
[ %]
0 25 50 75 100 125 150 175Relative Humidity [%]
Ice
Liquid
0
2
4
6
8
10
Pro
bab i
li ty
[ %]
0 25 50 75 100 125 150 175Relative Humidity [%]
40N-60N
Ice
Liquid
0
2
4
6
8
10
Pro
bab i
li ty
[ %]
0 25 50 75 100 125 150 175Relative Humidity [%]
40N-60N
Ice
Liquid
0
2
4
6
8
10
Pro
bab i
li ty
[ %]
0 25 50 75 100 125 150 175Relative Humidity [%]
Ice
Liquid
0
2
4
6
8
10
Pro
bab i
li ty
[ %]
0 25 50 75 100 125 150 175Relative Humidity [%]
40N-60N
Ice
Liquid
0
2
4
6
8
10
Pro
bab i
li ty
[ %]
0 25 50 75 100 125 150 175Relative Humidity [%]
40N-60N
Ice
Liquid
0
2
4
6
8
10
Pro
bab i
li ty
[ %]
0 25 50 75 100 125 150 175Relative Humidity [%]
Ice
Liquid
0
2
4
6
8
10
Pro
bab i
li ty
[ %]
0 25 50 75 100 125 150 175Relative Humidity [%]
40N-60N
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
9
Performance MOZAIC Humidity Device in Clouds:Evaporation of Ice Crystals ???????
• Clouds are clearly detected as „RHI-burst“ to 200% by Ly(α)-Total H2O • In clouds the MOZAIC-Humidity Device not exceeding 100% RHI
13:00 13:30 14:00 14:30 15:00Time / UTC
0
50
100
150
200
Rel
. Hum
idity
ove
r Ice
/ %
MOZAIC FISH Total H2O
SPURT : MOZAIC and FISH aboard Learjet-aircraft, 22-08-2002: Monastir (Algeria) - Hohn (Germany)
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
10
• Small scale phenomenon(ΔX < 200 km, ΔZ < 1-2 km)
• Difficult to see by satellites• Importance:
contrail & cirrus formation;radiative balance; OH formation
0 50 100 150 200 250 300 350 400 450 5000
500
1000
1500
2000
2500Summer |pv| < 2 Δ time < 0.0022
Freq
uenc
y
ISS horizontal extent [km]
Freq
uenc
y
ISS horizontal extent [km]
0 50 100 150 200 250 300 350 400 450 5000
500
1000
1500
2000
2500Summer |pv| < 2 Δ time < 0.0022
Freq
uenc
y
ISS horizontal extent [km]
Freq
uenc
y
ISS horizontal extent [km]
0 50 100 150 200 250 300 350 400 450 5000
500
1000
1500
2000
2500Summer |pv| < 2 Δ time < 0.0022
Freq
uenc
y
ISS horizontal extent [km]
Freq
uenc
y
ISS horizontal extent [km]
0 50 100 150 200 250 300 350 400 450 5000
500
1000
1500
2000
2500Summer |pv| < 2 Δ time < 0.0022
Freq
uenc
y
ISS horizontal extent [km]
Freq
uenc
y
ISS horizontal extent [km]
0 50 100 150 200 250 300 350 400 450 5000
500
1000
1500
2000
2500Summer |pv| < 2 Δ time < 0.0022
Freq
uenc
y
ISS horizontal extent [km]
Freq
uenc
y
ISS horizontal extent [km]
0 50 100 150 200 250 300 350 400 450 5000
500
1000
1500
2000
2500Summer |pv| < 2 Δ time < 0.0022
Freq
uenc
y
ISS horizontal extent [km]
Freq
uenc
y
ISS horizontal extent [km]
0 50 100 150 200 250 300 350 400 450 5000
500
1000
1500
2000
2500Summer |pv| < 2 Δ time < 0.0022
Freq
uenc
y
ISS horizontal extent [km]
Freq
uenc
y
ISS horizontal extent [km]
0 50 100 150 200 250 300 350 400 450 5000
500
1000
1500
2000
2500Summer |pv| < 2 Δ time < 0.0022
Freq
uenc
y
ISS horizontal extent [km]
Freq
uenc
y
ISS horizontal extent [km]
0 25 50 75 100 125 150 175Relative Humidity [% , Ice]
0
2
4
6
8
10
Prop
abilit
y [%
]
ECMWF
MOZAIC
40N-60N
• 30% of the UT showsice super saturation (ISS)
• Global models do not reproduceISS
• ISS relates with sub-visiblecirrus
Horizontal extentof ISS regions
MOZAIC: Ice Super Saturation (ISS) in the UT
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
11
-100 100-50 0AIRS - MOZAIC RH (liq.%)
50
RH (liq.%)
MOZAIC
0
AIRS
20 40 60 80 100 120
MOZAIC- UTH: Comparison with AIRS-Satellite over 2003(Work by Co PI: Andrew Gettelman, NCAR, Boulder, USA)
Development of „matching“ citeria of coincidence in space and time:A priori estimation of contribution of natural variabilityDirect comparison at (x,y,z,t)Indirect by optimizing statistics of coincidence by using backward trajectories
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
12
-3 -2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 3Temperature Difference Aircraft minus MOZAIC (K)
0
2
4
6
8
10
12
Rel
ativ
e O
ccur
ence
(Bin
=0.1
K) i
n %
Temperature Measurements Using TAT-Housings: Comparison Temperature Aircraft versus MOZAIC
Temp.
Spec.Hum.
Rel.Hum.
In addition, important aspect at low temperatures: Which H2O-saturation pressure Es(T)-table has been applied ???
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
13
Development of automatic In-flight Calibration (IFC)[Smit et al., Journal of Oceanic and Atmospheric Technology, May 2008]
Based on the technology and experience obtainedduring 8 years of MOZAIC-operation.
Long-term zero drift of MOZAIC-device,particularlyat low temperatures, is the critical and accuracydetermining parameter
On-line determination of long term zero drift duringdry stratospheric episodes (5ppmv water vapor)as a function of temperature.On-Line correction of zero drift of RH-measurements
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
14
MOZAIC In-Flight Calibration (IFC): Validation
15:00 16:00 17:00Time / UTC
0
10
20
30
RH
I / %
0
1
2
3
Pote
ntia
l Vor
ticity
/ pv
u
CASHAICLyman-AlphaPV
-60
-55
-50
Tem
pera
ture
/ °C
-8 -4 0 4 8RH(AIC) - RH(MOZAIC) [% RH]
0
2
4
6
8
10
12
Alti
tude
[km
]Comparison with MOZAIC In-flight comparison during SPURT
with Ly(α)-Hygrometer (FISH)
RH(IFC) – RH (MOZAIC) [%RH]
IFC
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
15
Candidates for Automatic Monitoring Humidityby Commercial Aircraft
WVSS-II
H 2 O -S e n s o r
AIRCRAFTSKIN
SENSORSRH: HUM ICAP-HT : PT100
DEICINGHEATER
BOUNDARY LAYERSCONTROL HOLES
RIGHT ANGLEPRODUCESPARTICLE
SEPARATION
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
16
Only internal reports
Not known
Not known
4 s
0.5 ppmv
5-10% of Mix. Ratio
6-12 km
Not proven
Rosemount (??)-Not known
Lyman(α) Fluorescence
~20 (estimated)
~20x8x8 cm
2 kg
FLASH
Under investigation (IAGOS)???Only internal
reportsPeer reviewed
literatureDocumentation of performance
Not KnownNot KnownNot ProvenProven, every ½yearMaintenance
Not KnownNot KnownNot provenProven (12 yrs MOZAIC)
Long term stability
1s1s2s 5s (0km), 60s (12km)Time response
Not known1 ppmv70 ppmv5% Rel. Hum.Detection Limit
Not known5-10% of Mix. Ratio
5-10% of Mix. Ratio
5-10% of Rel. Hum.Accuracy
0-12 km0-12 km0-6 km0-12 kmAltitude Range
Not provenNot provenNot proven every 6 monthsCalibration frequency
Rosemount- Not known
External mounting of optical cell
Wall plate in AC skin
- Not known
Rosemount- No wall effects
Inlet system- Wall effects
Frostpoint (Surface acoustic wave chip)
Spectroscopic(Tunable Diode
Laser)
Spectroscopic(Tunable Diode
Laser)
Capacitive (Humicap)Principle
~20 (estimated)~50 (estimated)~20~20Price (kEuro)
~15x15x10 cm~25x25x15 cm23x13x8 cm14x12x7 cmInternal Box Size
2 kg103 kg2 kgWeight
SAW-FrostpointOpen Path TDLWVSS-IIMOZAIC
Compact Sensors for Measuring Humidity on In-Service Aircraft
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
17
US-NWS has installed on 25 UPS aircraft since 2005 , now in evaluation phase but with plans to extend to large numberPoor documentation on evaluation of performanceFZJ has evaluated in the laboratory in 2005 DWD has installed on three A320 of Lufthansa since 2007In the loop: plans to install on a MOZAIC/IAGOS A340 of Lufthansa ?
Can new airborne WVSS-II measure humidity in UT and LS?:State of the Art
Diode laser(2f-detection)
Compact(≈ 2.5 kg)
Designed for automatic on-line sampling ofhumidity from aircraft for weather forecasting
AMDAR
Goal NWS: Reduce radiosounding network and replace by AMDAR
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
18
Reports:• Aircraft Identification• Date • Time (UTC)• Position• Altitude (Pressure)• Temperature• Windspeed• Wind Direction• Planned: Water Vapor
Mass Mixing Ratio
AMDAR = Aircraft Meteorological DAta RelayAboard Commercial Aircraft For Weather Forecasting
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
19
190 210 230 250 270 290 310Frostpoint Temperature Reference Hygrometer [K]
-0.2
-0.1
0
0.1
0.2
0.3
0.4
Rel
. Dev
iatio
n W
VSS
from
Ref
. [(W
VSS
-Ref
.)/R
ef.]
(WV
SS a
nd R
ef. i
n vo
lum
e m
ixin
g ra
tio)
190
210
230
250
270
290
310
Fros
tpoi
nt T
empe
ratu
re W
VSS
II [K
]
190 210 230 250 270 290 310Frostpoint Temperature Reference Hygrometer [K]
-0.2
-0.1
0
0.1
0.2
0.3
0.4
Rel
. Dev
iatio
n W
VSS
from
Ref
. [(W
VSS
-Ref
.)/R
ef.]
(WV
SS a
nd R
ef. i
n vo
lum
e m
ixin
g ra
tio)
190
210
230
250
270
290
310
Fros
tpoi
nt T
empe
ratu
re W
VSS
II [K
]
Frost Point TemperatureRel.Deviation WVSS from Ref.
Can new airborne WVSS-II measure humidity in UT and LS???:Performance tests at Environmental Simulation Facility at Jülich, Germany
WVSS at Frostpoint Temperatures:Above ~290 K: No reliable signal225 K – 290 K: Good performance:
Accuracy ±(5-10)%215 K – 225 K: Rapid declining sensitivity,
Limited accuracy: <±(10-15)% Below ~ 215 K: Below detection limit (80 ppmv)
Poor to bad performance in UT/LS
Diode laser(2f-detection)
Compact(≈ 2.5 kg)
Designed for automatic on-line sampling ofhumidity from aircraft for weather forecasting
AMDAR
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
20
Pre-and Post flight calibration every 500 flight hours) [Helten et al. 1998]In-flight comparisons (In-service & Research) [Helten et al., 1999]Evaluation in first SPARC-water vapor assessment [2000 report]Development in-flight calibration (IFC) method [Smit et al., 2008]Evaluation of detection of ice superation saturation [in-preparation]Assessment of performance of 12 years of MOZAIC-flight operation[in preparation]
12 year climatology of MOZAIC-H2O/T data available in MOZAIC-database at ToulouseParticipating in COST-action: WaVaCS (Water Vapor in the Climate System)
Participating in new, second SPARC water vapor assessmentNew instruments are under investigations.
MOZAIC/IAGOS: Summary QA-H2O/T Performance
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
23
Source: Tompkins, Gierens and Rädel, Quart.J.Roy.Met.Soc, 2007
ECMWF Model Include Ice Super-Saturation
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
24
-3 -2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 3Temperature Difference Aircraft minus MOZAIC (K)
0
2
4
6
8
10
12
Rel
ativ
e O
ccur
ence
(Bin
=0.1
K) i
n %
MOZAIC: Comparison Temperature Aircraft versus MOZAIC]
⎟⎟⎠
⎞⎜⎜⎝
⎛⋅⎟⎟⎠
⎞⎜⎜⎝
⎛ −+⋅= 2
V
VP Mc2
cc1SATTAT
Both measured with Rosemount TATAssumption full adiabatic conversion:
Measurement of TAT (σ=±0.25K)Determination M from TAP (σ=±0.25hPa)& SAP (σ=±0.35hPa)Determination SAT (σ=±0.50K)
Practice: TAT-recovery 99.5-99.7% Correction tables based on wind ductmeasurements (made in 1960/1970‘s)
Dependece on angle of attackDependence on location at aircraft skinRemaining sources of uncertainties
TAT = Total Air TemperatureSAT = Static Air TemperatureTAP = Total Air PressureSAT = Static Air Pressure
=0.2
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
25
Rosemount-TAT inlet systems: No indication of evaporation of ice crystalsEvaporation of liquid droplets
Large temperature sensitivity of H2O-saturation:Review of water vapor saturation tables at low temperaturesTemperature measurement needs more attention:
- Adiabatic recovery factor- Location at aircraft- Comparison with other in-situ temperature sensing technics
Scale analysis of spatial and temporal distribution of ISS
Climate impact of ISS
Outstanding Issues UTH-ISS Observations
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
26
MOZAIC Humidity Device: Performance and Quality Assurance
♦ Evaluation of two year record of pre- and post-flight calibrations
♦ Results agree well with in-flightinter comparisons[Helten et al., J.Geophys.Res.1999]
Calibration procedure:1. Pre-flight calibration: a1(Ti) & b1(Ti)
- Installation in A340- ≈500 h of flight operation- Exchange of MHD
2. Post-flight calibration: a2(Ti) & b2(Ti)- Cleaning RH- & T-sensor
3. Pre-flight calibration- Etc. etc.
RHCAL(Ti) =a (Ti)+b (Ti) x RHUNCAL (Ti)
Uncertainty of RH is derived from:• Difference between pre-and post
flight calibration of RH• Uncertainty Temperature
-60 -40 -20 0 20Static Air Temperature
0
2
4
6
8
10
Abs
.Err
or o
f Rel
.Hum
i. [%
RH
]
12 9 6 3 0
Altitude [km]
All Data 1999/2000
In: Helten et al., J.Geophys.Res., 1998
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
27
-13 -12 -11 -10 -9 -8 -7Longitude
70
80
90
100
110
120H
2O M
ixin
g R
atio
[ppm
v]
POLINATMOZAIC
Section ASection B Section C
POLINAT
MOZAIC
MOZAIC-Humidity: In-Flight Comparison with Frost Point Hygrometer (Ovarlaz) on Falcon (DLR/Nov.1997)
[Helten et al., J.Geophys.Res.1999]
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
28
MOZAIC-UTH: Comparison with POEM III Satellite
POEM III= Polar Ozone and Aerosol Measurement III satellite operational sinceApril 1998Good agreement POEMwith MOZAIC (Slope=0.98)
Large variations due toAtmospheric variability &Limited resolution of POEM (ΔX=250 km)
Source: Nedoluha et al., POAM III measurements of water vapor in the upper troposphere and lower moststratosphere, J. Geophys. Res., 2002
Coincidence criterion: 2.5º x 2.5º x 1 km x 6 hTotal: 200 Coincidences April 1998-Feb.2000
Slope = 0.98 (r=0.70)Offset= 3.6 ppmv
0 200100 300 400
200
100
300
400
POEM-UTH (ppmv)
MO
ZAIC
-UTH
(ppm
v)
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
29
MOZAIC-UTH: Comparison with MLS/UARS Satellite
MLS observe no ice supersaturation (retrieval and/orlimited horizontal resolution)MLS lower than MOZAIC(Slope=0.64)
Large variations due toAtmospheric variability &Limited resolution of POEM (ΔZ=4-5 km)
Source: Read et al., UARS MicrowaveLimb Sounder upper tropospheric humidity measurement: Method and validation, J. Geophys. Res., 2001
Coincidence criterion: 1º x 1º x 1 km x 3 hTotal: 384 Coincidences Aug.1994-Dec.1997
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
30
Ice
Liquid
0
2
4
6
8
10
12
Pro
babi
lity
[%]
0 25 50 75 100 125 150 175Relative Humidity [%]
00N-20N
Ice
Liquid
0
2
4
6
8
10
12
Pro
babi
lity
[%]
0 25 50 75 100 125 150 175Relative Humidity [%]
20N-30N
Ice
Liquid
0
2
4
6
8
10
Pro
babi
lity
[%]
0 25 50 75 100 125 150 175Relative Humidity [%]
30N-40N
Ice
Liquid
0
2
4
6
8
10
Pro
babi
lity
[%]
0 25 50 75 100 125 150 175Relative Humidity [%]
40N-60N
MOZAIC: Distribution Relative Humidity in UT over AtlanticZ = 9-12 km, PV ≤ 2.0pvu, 10oW-70oW, Aug 1994 - June 2000
≈38% ISS
≈15% ISS≈15% ISS
≈22% ISS
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
31
Critical aspects on inlet system
Ice Super Saturation over North Atlantic:More than 35% of UTH ice super saturatedBut less than 1% of observations aresaturated to liquid
Separation solid / gas phaseParticle enhancementEvaporation droplets & crystalsWall memory effectsWell defined P & T (cq. SH & RH)-conditions
Ice
Liquid
0
2
4
6
8
10
Pro
babi
lity
[%]
0 25 50 75 100 125 150 175Relative Humidity [%]
40N-60N
Ice
Liquid
0
2
4
6
8
10
Pro
babi
lity
[%]
0 25 50 75 100 125 150 175Relative Humidity [%]
40N-60N
Ice
Liquid
0
2
4
6
8
10
Pro
babi
lity
[%]
0 25 50 75 100 125 150 175Relative Humidity [%]
40N-60N
MOZAIC
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
32
Performance MOZAIC Humidity Device & ISS:Artifacts due to Evaporation of Ice Crystals ???????
10 0 -10 -20 -30 -40 -50 -60 -70Temperature Ambient Air [oC]
0
10
20
30
40
50
60P
erce
ntag
e of
Mea
sure
men
ts
With
Sup
er S
atur
atio
n [%
]
SS to 100% RH to Liquid
SS to 100% RH to Ice(Corrected for Liquid Fraction)
SS to 100% RH to Liquid & Ice
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
33
MOZAIC-IFC: In-Flight Correction of Zero Drift of RH-measurements
230 240 250 260 270 280Sensor Temperature, TD [K]
-0.25
0
0.25
0.5
0.75
Sens
or S
igna
l Vol
tage
UD
[V]
D0
D0
UD,LS
230 240 250 260 270 280Sensor Temperature, TD [K]
-0.25
0
0.25
0.5
0.75
Sens
or S
igna
l Vol
tage
UD
[V]
D0
D0
UD,LS
230 240 250 260 270 280Sensor Temperature, TD [K]
-0.25
0
0.25
0.5
0.75
Sens
or S
igna
l Vol
tage
UD
[V]
D0D0
D0D0
UD,LS
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
34
Every 6 months cleaning sensor at airport:rins with destilled water (1 min) rins with alcohol ( 1min)heat out (1 min @ ~90oC)
Every 2 year overal check at service company:exchange humidity device and send to service companyoverall check of device (new sensors, calibration etc.).
Outlook:automatic cleaning procedure at airportcollaborations with companies for instrumental and QA
support (e.g.Vaisala)
Operational Aspects of MOZAIC-Humidity DeviceFrom Board Commercial Aircraft
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
35
Routine Aircraft Measurements in the Global Observing System:The Link Between Surface and Space
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
36
IAGOS-ERI
Integration of routine Aircraft measurements into a Global Observing System –
a European Research Infrastructure
Routine Aircraft Measurements Routine Aircraft Measurements in a Global Observing System:in a Global Observing System:
The Link Between Surface and SpaceThe Link Between Surface and Space
http://www.fz-juelich.de/icg/icg-2/iagos
H2O from MOZAIC-IAGOS // Herman Smit/FZJ WaVacs-WG1 Lindenberg 21-23 May 2008
37
• 4/2009 IAGOS Design Study completed, - Prototypes available, - Partner airlines committed
• 2009 First aircraft equipped and commissioned: O3, CO, H2O, Cloud Droplet Probe, NOy
• 2010 Certification for CO2 and aerosol• 2016 20 aircraft equipped and commissioned• 2028 20 years of data available
~ 150 000 flights
http://www.fz-juelich.de/icg/icg-ii/iagosCoordinator: Dr. Andreas Volz-Thomas
E-mail: [email protected]
IAGOS-ERI: Time Table