csip & cops workshop 2009 tuesday, october 27 th
DESCRIPTION
Ice crystals properties retrieval within ice and mixed-phase clouds using the Doppler polarimetric radar TARA. Y. Dufournet , C.M.H Unal, S. Placidi H.W.J Russchenberg. CSIP & COPS workshop 2009 Tuesday, October 27 th. transmitter. receiver. COPS status – TU Delft. FMCW radar TARA. V. - PowerPoint PPT PresentationTRANSCRIPT
IRCTR - International Research Centre for Telecommunication and Radar
AATTMMOOSS
Ice crystals properties retrieval within ice and mixed-phase clouds
using the Doppler polarimetric radar TARA.
CSIP & COPS workshop 2009Tuesday, October 27th
Y. Dufournet , C.M.H Unal, S. Placidi
H.W.J Russchenberg
IRCTR - International Research Centre for Telecommunication and Radar
AATTMMOOSS
DelftUniversity ofTechnology
2
COPS status – TU Delft
Outlines :
Cloud microphysical Retrieval principle
Case study and main use of COPS facilities
transmitter
receiver
H HV V
TARA
12 m
FMCW radar TARA
- Located on Supersite H (Hornisgrinde)
- measurements performed within:
ice or mixed-phase cloud (only the ice phase)
Precipitation
(3.3 GHz – 10 cm)
IRCTR - International Research Centre for Telecommunication and Radar
AATTMMOOSS
DelftUniversity ofTechnology
3
Spectral polarimetric parameter - Principle
Particles with different size, habit, orientation
≠ fall velocities, particle axis ratio
0velocity
Spectral reflectivity
DRsZ
VVsZHHsZ
Doppler effect
Polarimetric behaviorra
dar
+Spectral polarimetric
parameters
( )( )
( )HH
DRVV
sZ vsZ v
sZ v
Isolate different
group of particles
IRCTR - International Research Centre for Telecommunication and Radar
AATTMMOOSS
DelftUniversity ofTechnology
4
Microphysical retrieval : resulting parameters
hei
ght
time
Polarimetric information
Doppler information
Radar cell
Numb. of particles types
Particle orientation
Particle habits
PSD for each particle type
radial wind, spectral broadening
Assumption based
Retrieved Parameters
)(vsZHH
)(vsZVV
)(, vsL hDR
, ( )DR vsL v
)(vsZDR
( )cos v
Forward model
Detailed microphysical analysis
IRCTR - International Research Centre for Telecommunication and Radar
AATTMMOOSS
DelftUniversity ofTechnology
5
Measurement at a microphysical mode– 21/07/07
-40 -30 -20 -10 0 10 20 30 40
15:39:03 15:51:19 16:03:36 16:15:52 16:28:09 16:40:26
1
529
1057
1585
2113
2641
3169
3697
4225
4753
5281
time
height (m)
Reflectivity [dB] MB VV
Profiles
Ran
ge b
in
box boundaries: x1= 1618 / x2= 2391y1= 491 / y2= 198
1 241 481 721 961 1201 1441 1681 1921 21611
50
99
148
197
246
295
344
393
442
491
Precipitation
Ice or mixed-phase cloud
Melting layer
Drizzle
Boundary layer top
Retrieval zone
time
heig
ht
Based on a retrieval technique !
IRCTR - International Research Centre for Telecommunication and Radar
AATTMMOOSS
DelftUniversity ofTechnology
6
Retrieval orientation and particle habit
simplified particle categorization
50 100 150
10
20
30
40
50
60
70
no data
dominantpristine
dominantaggregates
aggregates
-40 -30 -20 -10 0 10 20 30 40
15:39:03 15:51:19 16:03:36 16:15:52 16:28:09 16:40:26
1
529
1057
1585
2113
2641
3169
3697
4225
4753
5281
time
height (m)
Reflectivity [dB] MB VV
Profiles
Ran
ge b
in
box boundaries: x1= 1618 / x2= 2391y1= 491 / y2= 198
1 241 481 721 961 1201 1441 1681 1921 21611
50
99
148
197
246
295
344
393
442
491
plates
dendrites
simplified orientation categorization
1700 1800 1900 2000 2100 2200 2300200
250
300
350
400
450
No data
no orient.
verticalmainly
horizont.mainlyMainlyhorizontal
Mainlyvertical
No orientation
No data
Horizontally aligned plates (+ dendrites) and few aggregates
Vertically aligned plates (+ dendrites) and few aggregates
Strong aggregation
Mainly aggregates and few plates
orientation
habits
simplified particle categorization
50 100 150
10
20
30
40
50
60
70
no data
dominantpristine
dominantaggregates
aggregates
simplified particle categorization
50 100 150
10
20
30
40
50
60
70
no data
dominantpristine
dominantaggregates
aggregates
IRCTR - International Research Centre for Telecommunication and Radar
AATTMMOOSS
DelftUniversity ofTechnology
7
Comparison particle habits
-50 -40 -30 -20 -10 0 10 200
2000
4000
6000
8000
10000
12000
dry temperature (°C)
alt
itu
de
(m
)
M site - radiosonde 21/07/07 - 18:02
Radiosonde launch
ATR 42 flight
Plate production region
Cloud top region
PMS 2D-C probes images
IRCTR - International Research Centre for Telecommunication and Radar
AATTMMOOSS
DelftUniversity ofTechnology
8
simplified particle categorization
50 100 150
10
20
30
40
50
60
70
no data
dominantpristine
dominantaggregates
aggregates
Retrieval PSD and ambient wind
2.5 3 3.5 43000
3500
4000
4500
5000
5500
6000
6500
median volume diameter for aggregates (mm)
altitu
de ab
ove s
ea le
vel (m
)
D0 agg. retrieval
agg.plates + agg.
D0 agg.
0.31 0.32 0.33 0.34 0.35 0.36 0.37 0.38 0.39 0.44800
5000
5200
5400
5600
5800
6000
6200
median volume diameter (mm)
altitu
de
ab
ove
se
a le
ve
l (m
)
D0 pla.
102
103
104
105
3000
3500
4000
4500
5000
5500
6000
6500
number of aggregates
altitd
ue ab
ove s
ea le
vel (m
)
agg.
plates + agg.
Nt agg.
1500 2000 2500 3000 3500 40004800
5000
5200
5400
5600
5800
6000
6200
number of particles
altitu
de
ab
ove
se
a le
ve
l (m
)
Nt pla.
Vertical ambiant wind
Obtained from modified gamma distribution
Wind shear
Convergence zone
v0
IRCTR - International Research Centre for Telecommunication and Radar
AATTMMOOSS
DelftUniversity ofTechnology
9
Comparison PSD
ATR 42 retrieved
IWC
Nt
Good agreement
IRCTR - International Research Centre for Telecommunication and Radar
AATTMMOOSS
DelftUniversity ofTechnology
10
Cloud processes – possible explanation
m.s-1
Mean vertical Doppler velocity from TARA
Pristine ice prod.
aggregation
Orographic enhancement
Strong updraft
blocking area
Only agg. precipitate
Plates fully blocked
vTARA = vparticles
IRCTR - International Research Centre for Telecommunication and Radar
AATTMMOOSS
DelftUniversity ofTechnology
11
Main achievements using COPS data set
• microphysical retrieval: promising results on the cloud observation processes assumptions tested and improved leading to good agreements when compared with other instruments
• 3D wind measurements: corrected and assessed with radiosondes measurements within optically thick clouds and precipitation
Conclusion
What is next ?
- Processing the remaining days
- Full Assessment and validation of the microphysical retrieval
IRCTR - International Research Centre for Telecommunication and Radar
AATTMMOOSS
DelftUniversity ofTechnology
12
EarthCARE SIMulator - ECSIM
Earth Cloud Aerosols Radiaton Explorer by ESALaunch date: 2013
EarthCARE mission end2end SIMulator – ECSIM Simulate all the 4 EarthCARE instruments and the satellite platform
Model Atmosphere
Model Atmosphere
Forward Models
Forward Models
Syntheticobservations
Syntheticobservations
Space-borne radar and lidar Ground-based / aircraft radar and lidar
Satellite imager and broadband radiometer
(Courtesy of Simone Placidi)
cloud scene creation ( PSD, reff, shape
parameter, surface properties, cloud/aerosol
information…) input from LES models, fractal cloud
generator
IRCTR - International Research Centre for Telecommunication and Radar
AATTMMOOSS
DelftUniversity ofTechnology
13
Validation – assessment with ECSIM
Microphysical data retrieved
Comparison with COPS
instrumentation
(Courtesy of Simone Placidi)
Optical Depth of original scene
Simulated 94 GHz Radar Reflectivity (ground)
Synthetic observations
IRCTR - International Research Centre for Telecommunication and Radar
AATTMMOOSS
DelftUniversity ofTechnology
14
Thank you!
IRCTR - International Research Centre for Telecommunication and Radar
AATTMMOOSS
DelftUniversity ofTechnology
15
Heig
ht [m
]
Reflectivity [dBZ] EL=75 deg. D20070703
11.55 11.6 11.65 11.7 11.75 11.8 11.85
2000
4000
6000
-40
-20
0
20
40
Heig
ht [m
]
Horizontal wind speed [m s-1] D20070703
11.55 11.6 11.65 11.7 11.75 11.8 11.85
2000
4000
6000
10
20
30
Decimal time UTC [hours]
Heig
ht [m
]Horizontal wind direction [deg.] related to North D20070703
11.55 11.6 11.65 11.7 11.75 11.8 11.85
2000
4000
6000
150
200
250
300
Example horizontal particle motion (COPS)
Wind shear at 4000 m
10 days processed
(Courtesy Christine Unal)
21 min averaged
Observation of 3D particle motion at high resolution within ice/mixed-phase clouds and precipitation
IRCTR - International Research Centre for Telecommunication and Radar
AATTMMOOSS
DelftUniversity ofTechnology
16
EarthCARE SIMulator
INPUT OUTPUTSIMULATIONS
Cloud scene- Scene dimensions
- Atmospheric properties
- Surface properties
- Clouds/aerosols info
- Scattering regions
- ext, LWC, Reff
- Gamma / log-normal distribution
- shape parameter
- min/max value of Reff for DSD
- From LES, CRM, fractal cloud generator
Outputs- Radar Reflectivity
- Lidar return/ extinction/ backscatter
- COT - Reff – LWP
- Fluxes
Forward/Instruments models- ground
- Radar (5GHz, 32Ghz, 94 GHz)
- Lidar (0.353 nm)
- Space:
- Radar
- Lidar
- Multi Spectral Imager
- Broadband radiometer
IRCTR - International Research Centre for Telecommunication and Radar
AATTMMOOSS
DelftUniversity ofTechnology
17
Radar measurement from TARAtransmitter
receiver
H HV V
Doppler and Polarimetric capabilities:
- transmit and receive horizontally (H) or vertically (V) change of the polarization state every 1ms: HH HV VV
-Antennas at 45° improve the polarimetric contrast
Other requirements for cloud observation:
- High resolution 15 m range resolution
1 profile every 1.5 s
- For mixed-phase clouds : at 3.3 Ghz, reflectivity of supercooled water droplets below the noise level – direct measurement of the ice crystals!
TARA: Transportable Atmospheric RAdar
(FMCW – S band)
12 m)(vsZHH )(vsZVV )(, vsL hDR
, ( )DR vsL v)(vsZDR
Spectral polarimetric parameter
( )cos v
IRCTR - International Research Centre for Telecommunication and Radar
AATTMMOOSS
DelftUniversity ofTechnology
18
-40 -30 -20 -10 0 10 20 30 40
15:39:03 15:51:19 16:03:36 16:15:52 16:28:09 16:40:26
1
529
1057
1585
2113
2641
3169
3697
4225
4753
5281
time
height (m)
Reflectivity [dB] MB VV
Profiles
Ran
ge b
in
box boundaries: x1= 1618 / x2= 2391y1= 491 / y2= 198
1 241 481 721 961 1201 1441 1681 1921 21611
50
99
148
197
246
295
344
393
442
491
Case study – 21/07/2007 (COPS – EUFAR)
France
Convective and Orographically-induced Precipitation Study
Precipitation
Ice or mixed-phase cloud
Melting layer
Drizzle
Meteorological situation:
Frontal activities and mesoscale convective system development with orographic inhancement
Boundary layer top
Retrieval zoneHornisgrindeBlack Forest
IRCTR - International Research Centre for Telecommunication and Radar
AATTMMOOSS
DelftUniversity ofTechnology
19
Measurement type overview h
eig
ht
time
Polarimetric information
Doppler information
Radar cell
-3 -2.5 -2 -1.5 -1 -0.5-15
-10
-5
0
sZhh
[dB
]
optimization result: 2382 / 394
-3 -2.5 -2 -1.5 -1 -0.5-0.5
0
0.5
1
1.5
sZdr
[dB
]
vertical velocity m/s
D0agg = 3.75 [mm]
Nwagg = 363 [mm-1m-3]
0 = 0.55 [ms-1]
v0 = 0.94 [ms-1]
IWC = 0.022 [g.m-3]Nt = 371 [particles]shape factor = 0
Microphysical model
Simulated sZDR(v) + sZHH(v)
Numb. of particles types
Particle orientation
Particle habits
Least square fit algorithm
Signal improvement
PSD for each particle type
radial wind, spectral broadening
Velocity
Assumption based
Particle motion
Cloud microphysical retrieval
Mean Doppler velocity
Doppler width
)(vsZHH
)(vsZVV
)(, vsL hDR
, ( )DR vsL v
)(vsZDR
( )cos v
)(vsZDR
)(vsZHH
IRCTR - International Research Centre for Telecommunication and Radar
AATTMMOOSS
DelftUniversity ofTechnology
20
Type of measurements h
eig
ht
time
Polarimetric information
Doppler information
Radar cell
Numb. of particles types
Particle orientation
Particle habits
PSD for each particle type
radial wind, spectral broadening
Assumption based
Wind mode : moment computation from 3 beams
Microphysical mode : retrieval
Mean Doppler velocity
Doppler width
)(vsZHH
)(vsZVV
)(, vsL hDR
, ( )DR vsL v
)(vsZDR
( )cos v
Particle fall velocity, horizontal wind speed and direction