H2O from MOZAIC-IAGOS // Herman Smit/ FZJ ISSI-H2O Bern 11-14 Feb.2008 1 Monitoring Atmospheric Humidity from Commercial Aircraft by MOZAIC-IAGOS: In-sights from the Past and Present into the Future Herman G. J. Smit ([email protected]) Forschungszentrum Juelich (ICG-2) H 2O- Sensor A IR C RA FT SK IN SEN SO R S RH :H U M IC AP-H T :PT100 D EIC IN G HEATER BOUNDARY LAYERS CONTROL H OLES RIG H T ANGLE PRODUCES PA R TIC LE SEPA R A TIO N Past and Present: MOZAIC Humidity Sampling Quality Assurance & Synergy of Data Future: IAGOS 0 2 4 6 8 0 R] 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 A B 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 200 210 220 230 240 250 T em p erature [ K] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 A B 0 2 4 6 8 0 R] 0 2 4 6 8 0 R] 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 A B 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 200 210 220 230 240 250 T em p erature [ K] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 A B 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 A B 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 A B 0 2 4 6 8 0 R] 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 A B 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 200 210 220 230 240 250 T em p erature [ K] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 A B 0 2 4 6 8 0 R] Ice Liquid 0 2 4 6 8 10 P robability [% ] 0 25 50 75 100 125 150 175 Relative Hum idity [% ] 40N-60N 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 A B 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 200 210 220 230 240 250 T em p erature [ K] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 A B 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 A B 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 200 210 220 230 240 250 Tempe ratu re [K ] 0 50 100 150 200 250 R e la tive H um id ity [% Ic e ] N= 61389 Samples with VN> 0 A B A = Saturationto Liquid B = Homog. Nucleation M OZAIC 0 9 6 3 0 0 9 6 3 0 -6 0 -4 0 -20 0 20 Sta tic A ir T em perature 0 2 4 6 8 10 A bs.E rr o r o f R el.H um i. [% RH] 12 9 6 3 0 A ltitu d e [k m] In: Helten et al., J .Geophys.R es., 1998
34
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Monitoring Atmospheric Humidity from Commercial Aircraft by MOZAIC-IAGOS:
Monitoring Atmospheric Humidity from Commercial Aircraft by MOZAIC-IAGOS: In-sights from the Past and Present into the Future Herman G. J. Smit ( [email protected] ) Forschungszentrum Juelich (ICG-2). Past and Present: MOZAIC. Humidity Sampling. Quality Assurance & Synergy of Data. - PowerPoint PPT Presentation
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H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008
1
Monitoring Atmospheric Humidity from Commercial Aircraft by MOZAIC-IAGOS:
In-sights from the Past and Present into the Future
Herman G. J. Smit ([email protected])Forschungszentrum Juelich (ICG-2)
Regular calibration (every 500 flight hours) In environmental simulation chamber Against Lyman()-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-flight intercomparisons [Helten et al. Geophys.Res.1998, 1999]
-60 -40 -20 0 20S ta tic A ir T e m p er a tu r e
0
2
4
6
8
10
Abs
.Err
or o
f R
el.H
umi.
[% R
H]
1 2 9 6 3 0
A lt itu d e [k m ]
A ll D a ta 1 9 9 9 /2 0 0 0
In: Helten et al., J.Geophys.Res., 1998
H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008
7
MOZAIC Relative Humidity in Upper Troposphere (UT) over Atlantic
• MOZAIC provided the first
climatology of humidity in the UT • Large variability in time and
space
-20
0
20
40
60
La
titu
de
5102030405060708090100
Jan
95
Jan
96
Jan
97
Jan
98
Jan
99
Jan
00
• More than 30% of UTH-data
are Ice Super Saturated (ISS)• But less than 0.5-1% of data
are 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 175RelativeHumidity [%]
40N-60N
Ice
Liquid
0
2
4
6
8
10
Pro
bab i
li ty
[ %]
0 25 50 75 100 125 150 175RelativeHumidity [%]
40N-60N
Ice
Liquid
0
2
4
6
8
10
Pro
bab i
li ty
[ %]
0 25 50 75 100 125 150 175RelativeHumidity [%]
40N-60N
Ice
Liquid
0
2
4
6
8
10
Pro
bab i
li ty
[ %]
0 25 50 75 100 125 150 175RelativeHumidity [%]
40N-60N
Ice
Liquid
0
2
4
6
8
10
Pro
bab i
li ty
[ %]
0 25 50 75 100 125 150 175RelativeHumidity [%]
40N-60N
Ice
Liquid
0
2
4
6
8
10
Pro
bab i
li ty
[ %]
0 25 50 75 100 125 150 175RelativeHumidity [%]
Ice
Liquid
0
2
4
6
8
10
Pro
bab i
li ty
[ %]
0 25 50 75 100 125 150 175RelativeHumidity [%]
40N-60N
Ice
Liquid
0
2
4
6
8
10
Pro
bab i
li ty
[ %]
0 25 50 75 100 125 150 175RelativeHumidity [%]
40N-60N
Ice
Liquid
0
2
4
6
8
10
Pro
bab i
li ty
[ %]
0 25 50 75 100 125 150 175RelativeHumidity [%]
Ice
Liquid
0
2
4
6
8
10
Pro
bab i
li ty
[ %]
0 25 50 75 100 125 150 175RelativeHumidity [%]
40N-60N
Ice
Liquid
0
2
4
6
8
10
Pro
bab i
li ty
[ %]
0 25 50 75 100 125 150 175RelativeHumidity [%]
40N-60N
Ice
Liquid
0
2
4
6
8
10
Pro
bab i
li ty
[ %]
0 25 50 75 100 125 150 175RelativeHumidity [%]
Ice
Liquid
0
2
4
6
8
10
Pro
bab i
li ty
[ %]
0 25 50 75 100 125 150 175RelativeHumidity [%]
40N-60N
H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008
8
Critical aspects on inlet system
Ice Super Saturation over North Atlantic: More than 35% of UTH ice super saturated But less than 1% of observations are saturated to liquid
Separation solid / gas phase Particle enhancement Evaporation droplets & crystals Wall memory effects Well 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
2 0 0 2 1 0 2 2 0 2 3 0 2 4 0 2 5 0T em p eratu re [K ]
0
5 0
1 0 0
1 5 0
2 0 0
2 5 0
Rel
ativ
e H
umid
ity
[% I
ce] N = 6 13 8 9 Sa m p les w ith V N > 0
2 0 0 2 1 0 2 2 0 2 3 0 2 4 0 2 5 0T em p eratu re [K ]
0
5 0
1 0 0
1 5 0
2 0 0
2 5 0
Rel
ativ
e H
umid
ity
[% I
ce] N = 6 13 8 9 Sa m p les w ith V N > 0
AB
A = Saturation to LiquidB = Homog. Nucleation
2 0 0 2 1 0 2 2 0 2 3 0 2 4 0 2 5 0T em p eratu re [K ]
0
5 0
1 0 0
1 5 0
2 0 0
2 5 0
Rel
ativ
e H
umid
ity
[% I
ce] N = 6 13 8 9 Sa m p les w ith V N > 0
2 0 0 2 1 0 2 2 0 2 3 0 2 4 0 2 5 0T em p eratu re [K ]
0
5 0
1 0 0
1 5 0
2 0 0
2 5 0
Rel
ativ
e H
umid
ity
[% I
ce] N = 6 13 8 9 Sa m p les w ith V N > 0
2 0 0 2 1 0 2 2 0 2 3 0 2 4 0 2 5 0T em p eratu re [K ]
0
5 0
1 0 0
1 5 0
2 0 0
2 5 0
Rel
ativ
e H
umid
ity
[% I
ce] N = 6 13 8 9 Sa m p les w ith V N > 0
2 0 0 2 1 0 2 2 0 2 3 0 2 4 0 2 5 0T em p eratu re [K ]
0
5 0
1 0 0
1 5 0
2 0 0
2 5 0
Rel
ativ
e H
umid
ity
[% I
ce] N = 6 13 8 9 Sa m p les w ith V N > 0
AB
A = Saturation to LiquidB = Homog. Nucleation
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
2 0 0 2 1 0 2 2 0 2 3 0 2 4 0 2 5 0T em p eratu re [K ]
0
5 0
1 0 0
1 5 0
2 0 0
2 5 0
Rel
ativ
e H
umid
ity
[% I
ce] N = 6 13 8 9 Sa m p les w ith V N > 0
2 0 0 2 1 0 2 2 0 2 3 0 2 4 0 2 5 0T em p eratu re [K ]
0
5 0
1 0 0
1 5 0
2 0 0
2 5 0
Rel
ativ
e H
umid
ity
[% I
ce] N = 6 13 8 9 Sa m p les w ith V N > 0
AB
A = Saturation to LiquidB = Homog. Nucleation
2 0 0 2 1 0 2 2 0 2 3 0 2 4 0 2 5 0T em p eratu re [K ]
0
5 0
1 0 0
1 5 0
2 0 0
2 5 0
Rel
ativ
e H
umid
ity
[% I
ce] N = 6 13 8 9 Sa m p les w ith V N > 0
2 0 0 2 1 0 2 2 0 2 3 0 2 4 0 2 5 0T em p eratu re [K ]
0
5 0
1 0 0
1 5 0
2 0 0
2 5 0
Rel
ativ
e H
umid
ity
[% I
ce] N = 6 13 8 9 Sa m p les w ith V N > 0
2 0 0 2 1 0 2 2 0 2 3 0 2 4 0 2 5 0T em p eratu re [K ]
0
5 0
1 0 0
1 5 0
2 0 0
2 5 0
Rel
ativ
e H
umid
ity
[% I
ce] N = 6 13 8 9 Sa m p les w ith V N > 0
2 0 0 2 1 0 2 2 0 2 3 0 2 4 0 2 5 0T em p eratu re [K ]
0
5 0
1 0 0
1 5 0
2 0 0
2 5 0
Rel
ativ
e H
umid
ity
[% I
ce] N = 6 13 8 9 Sa m p les w ith V N > 0
AB
A = Saturation to LiquidB = Homog. Nucleation
2 0 0 2 1 0 2 2 0 2 3 0 2 4 0 2 5 0T em p eratu re [K ]
0
5 0
1 0 0
1 5 0
2 0 0
2 5 0
Rel
ativ
e H
umid
ity
[% I
ce] N = 6 13 8 9 Sa m p les w ith V N > 0
2 0 0 2 1 0 2 2 0 2 3 0 2 4 0 2 5 0T em p eratu re [K ]
0
5 0
1 0 0
1 5 0
2 0 0
2 5 0
Rel
ativ
e H
umid
ity
[% I
ce] N = 6 13 8 9 Sa m p les w ith V N > 0
AB
A = Saturation to LiquidB = Homog. Nucleation
2 0 0 2 1 0 2 2 0 2 3 0 2 4 0 2 5 0T em p eratu re [K ]
0
5 0
1 0 0
1 5 0
2 0 0
2 5 0
Rel
ativ
e H
umid
ity
[% I
ce] N = 6 13 8 9 Sa m p les w ith V N > 0
2 0 0 2 1 0 2 2 0 2 3 0 2 4 0 2 5 0T em p eratu re [K ]
0
5 0
1 0 0
1 5 0
2 0 0
2 5 0
Rel
ativ
e H
umid
ity
[% I
ce] N = 6 13 8 9 Sa m p les w ith V N > 0
2 0 0 2 1 0 2 2 0 2 3 0 2 4 0 2 5 0T em p eratu re [K ]
0
5 0
1 0 0
1 5 0
2 0 0
2 5 0
Rel
ativ
e H
umid
ity
[% I
ce] N = 6 13 8 9 Sa m p les w ith V N > 0
2 0 0 2 1 0 2 2 0 2 3 0 2 4 0 2 5 0T em p eratu re [K ]
0
5 0
1 0 0
1 5 0
2 0 0
2 5 0
Rel
ativ
e H
umid
ity
[% I
ce] N = 6 13 8 9 Sa m p les w ith V N > 0
AB
A = Saturation to LiquidB = Homog. Nucleation
MOZAIC
H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008
9
Performance MOZAIC Humidity Device in Clouds Evaporation of Ice Crystals ???????
• Clouds are clearly detected as „RHI-burst“ to 200% by the Lyman ()-Total H2O
• In clouds the MOZAIC-Humidity Device not exceeding 100% RHI
13:30 14:00 14:30 15:00 15:30
Time / U TC
0
25
50
75
100
125
150
175
200
Re
l. H
um
idit
y o
ve
r Ic
e /
%
0
2
4
6
8
10
Po
ten
tia
l Vo
rtic
ity
/ p
vu
MOZAIC-Device
Lyman ( HygrometerPotential VorticityAltitudeAir Temperature
0 25 50 75 100 125 150 175R elative H um idity [% , Ice]
0
2
4
6
8
10
Pro
pabi
lity
[%
]
ECMW F
MOZAIC
40N-60N
• 30% of the UT shows ice super saturation (ISS)
• Global models do not reproduce ISS
• ISS relates with sub-visible cirrus
Horizontal extent of ISS regions
MOZAIC: Ice Super Saturation (ISS) in the UT
H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.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 proper „matching“ citeria of coincidence in space and time: A priori estimation of contribution of natural variability Direct comparison at (x,y,z,t) Indirect by optimizing statistics of coincidence by using backward trajectories
H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008
12
-3 -2 .5 -2 -1 .5 -1 -0 .5 0 0 .5 1 1 .5 2 2 .5 3T em p era tu re D iffe ren ce A irc ra ft m in u s M O Z A IC (K )
0
2
4
6
8
1 0
1 2
Rel
ativ
e O
ccur
ence
(B
in=
0.1
K)
in %
Involvment 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 ISSI-H2O Bern 11-14 Feb.2008
13
Development of Automatic In-flight Calibration (IFC)
Based on the technology and experience obtained during 8 years of MOZAIC-operation.
Long-term zero drift of MOZAIC-device, particularly at low temperatures, is the critical and accuracy determining parameter
On-line determination of long term zero drift during dry 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 ISSI-H2O Bern 11-14 Feb.2008
14
MOZAIC In-Flight Calibration (IFC): Validation
15:00 16:00 17:00
Time / UTC
0
10
20
30
RH
I /
%
0
1
2
3
Po
ten
tial
Vo
rtic
ity
/ p
vu
CASHAICLym an-AlphaPV
-60
-55
-50
Te
mp
era
ture
/ °
C
-8 -4 0 4 8R H (A IC ) - R H (M O Z A IC ) [% R H ]
0
2
4
6
8
1 0
1 2
Alt
itud
e [
km]
Comparison with MOZAIC In-flight comparison during SPURTwith Ly()-Hygrometer (FISH)
RH(IFC) – RH (MOZAIC) [%RH]
IFC
H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008
15
US-NWS has installed on 25 UPS aircraft since 2005 , now in evaluation phase but with plans to extend to large number
Poor documentation on evaluation of performance
FZJ has evaluated in the laboratory in 2005
DWD has installed on three A320 of Lufthansa since 2007
In 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 ISSI-H2O Bern 11-14 Feb.2008
16
MOZAIC WVSS-II Open Path TDL SAW-Frostpoint FLASH
Weight 2 kg 3 kg 10 2 kg 2 kg
Internal Box Size
14x12x7 cm 23x13x8 cm ~25x25x15 cm ~15x15x10 cm ~20x8x8 cm
H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008
23
-3 -2 .5 -2 -1 .5 -1 -0 .5 0 0 .5 1 1 .5 2 2 .5 3T em p era tu re D iffe ren ce A irc ra ft m in u s M O Z A IC (K )
0
2
4
6
8
1 0
1 2
Rel
ativ
e O
ccur
ence
(B
in=
0.1
K)
in %
MOZAIC: Comparison Temperature Aircraft versus MOZAIC]
2
V
VP Mc2
cc1SATTAT
Both measured with Rosemount TAT Assumption 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 only 99.5-99.7% Correction tables based on wind duct
measurements (made in 1960/1970‘s)
Dependece on angle of attack Dependence on location at aircraft skin Remaining 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 ISSI-H2O Bern 11-14 Feb.2008
24
Rosemount-TAT inlet systems: No indication of evaporation of ice crystals Evaporation of liquid droplets
Large temperature sensitivity of H2O-saturation: Review of water vapor saturation tables at low temperatures Temperature 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 ISSI-H2O Bern 11-14 Feb.2008
25
MOZAIC Humidity Device: Performance and Quality Assurance
Evaluation of two year record of pre- and post-flight calibrations Results agree well with in-flight inter 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-sensor3. 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 20S ta tic A ir T e m p er a tu r e
0
2
4
6
8
10
Abs
.Err
or o
f R
el.H
umi.
[% R
H]
1 2 9 6 3 0
A ltitu d e [k m ]
A ll D a ta 1 9 9 9 /2 0 0 0
In: Helten et al., J.Geophys.Res., 1998
H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008
26
-1 3 -1 2 -11 -1 0 -9 -8 -7L o n g itu d e
7 0
8 0
9 0
1 0 0
11 0
1 2 0
H2O
Mix
ing
Rat
io [
ppm
v]
P O L IN A TM O Z A IC
S ec tio n AS ec tio n B S ec tio n C
POLINAT
MOZA IC
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 ISSI-H2O Bern 11-14 Feb.2008
27
MOZAIC-UTH: Comparison with POEM III Satellite
POEM III= Polar Ozone and Aerosol Measurement III satellite operational since April 1998 Good agreement POEM with MOZAIC (Slope=0.98)
Large variations due to Atmospheric variability & Limited resolution of POEM (X=250 km)
Source: Nedoluha et al., POAM III measurements of water vapor in the upper troposphere and lower most stratosphere, 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
ZA
IC-U
TH
(pp
mv)
H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008
28
MOZAIC-UTH: Comparison with MLS/UARS Satellite
MLS observe no ice super saturation (retrieval and/or limited horizontal resolution) MLS lower than MOZAIC (Slope=0.64)
Large variations due to Atmospheric variability & Limited resolution of POEM (Z=4-5 km)
Source: Read et al., UARS Microwave Limb 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 ISSI-H2O Bern 11-14 Feb.2008
29
Ice
Liquid
0
2
4
6
8
10
12
Pro
ba
bili
ty [%
]
0 25 50 75 100 125 150 175R elative H um idity [% ]
00N-20N
Ice
Liquid
0
2
4
6
8
10
12
Pro
babi
lity
[%]
0 25 50 75 100 125 150 175R elative H um id ity [% ]
20N-30N
Ice
Liquid
0
2
4
6
8
10
Pro
babi
lity
[%]
0 25 50 75 100 125 150 175R elative H um id ity [% ]
30N-40N
Ice
Liquid
0
2
4
6
8
10
Pro
bab
ility
[%]
0 25 50 75 100 125 150 175R elative H um id ity [% ]
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% ISS15% ISS
22% ISS
H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008
30
Performance MOZAIC Humidity Device & ISS:Artifacts due to Evaporation of Ice Crystals ???????
10 0 -10 -20 -30 -40 -50 -60 -70Tem pera ture Am bien t A ir [oC ]
0
10
20
30
40
50
60P
erce
nta
ge
of
Me
asur
em
ent
s W
ith S
upe
r S
atu
ratio
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 ISSI-H2O Bern 11-14 Feb.2008
31
MOZAIC-IFC: In-Flight Correction of Zero Drift of RH-measurements
2 3 0 2 4 0 2 5 0 2 6 0 2 7 0 2 8 0S en so r T em p era tu re , T D [K ]
-0 .2 5
0
0 .2 5
0 .5
0 .7 5
Sen
sor
Sig
nal V
olta
ge U
D [
V]
D0
D0
UD,LS
0
0 .2 5S
enso
r V
olta
ge
UD
,LS [
V]
2 3 0 2 4 0 2 5 0 2 6 0 2 7 0 2 8 0S en so r T em p era tu re , T D [K ]
-0 .2 5
0
0 .2 5
0 .5
0 .7 5
Sen
sor
Sig
nal V
olta
ge U
D [
V]
D0
D0
UD,LS
2 3 0 2 4 0 2 5 0 2 6 0 2 7 0 2 8 0S en so r T em p era tu re , T D [K ]
-0 .2 5
0
0 .2 5
0 .5
0 .7 5
Sen
sor
Sig
nal V
olta
ge U
D [
V]
D0D0
D0D0
UD,LS
0
0 .2 5S
enso
r V
olta
ge
UD
,LS [
V]
H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008
32
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
company overall check of device (new sensors, calibration etc.).
Outlook: automatic cleaning procedure at airport collaborations with companies for instrumental and QA
support (e.g.Vaisala)
Operational Aspects of MOZAIC-Humidity Device From Board Commercial Aircraft
H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008