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87th AMS Annual Meeting
Water Water vapourvapour RamanRaman lidarlidar and and microwavemicrowave profilerprofiler: :
comparisonscomparisons and and synergiessynergies
F. Madonna, A. Amodeo, C. Cornacchia, G. D’Amico, L. Mona, G. Pappalardo
Istituto di Metodologie per l’Analisi Ambientale CNR-IMAA, Potenza, Italy
WG1 Workshop WaVaCS – Lindenberg 21 -23 May 2008
87th AMS Annual Meeting
BS
BS
DM
IF386 nm
PMTM
Nd:YAGLaser
M
M
M = mirror
P = pinhole
L = collimation lens
DM = dichroic mirror
BS = beam splitter
PMT = photomultiplier
IF = interferential filter
M = mirror
P = pinhole
L = collimation lens
DM = dichroic mirror
BS = beam splitter
PMT = photomultiplier
IF = interferential filter
M
L
P
355
nm
IF407 nm
PMT
DM
M
M
IF355 nm
PMT
IF407 nm
PMT
IF355 nm
PMT
BS
IF386 nm
PMT
DETECTORS: photomultiplierTHORN EMI 9202 QB355, 386, 407 nm
ACQUISITION: photon counting modeEG&G MCS - PCIMinimum dwell time 100 nsBandwidth 150 MHzPHILLIPS SCIENT. Fast discriminatorBandwidth 300 MHz
RECEIVING SYSTEM: Cassegrain telescope
Primary mirror diameter 0.5 mCombined focal length 5 mNight-time field of view 1 ÷ 2 mradDaytime field of view 0.2 mrad
LASER: Nd:YAG laser (Coherent – Infinity)
Max. Pulse Energy@ 355nm 170mJMaximum repetition rate 100HzBeam divergence <0.3 mradPulse duration 3 ÷ 4 ns
SPECTRAL SELECTION: interferential filter Wavelengths (nm) 386 407 355 Out of band rejection <10-10 <10-8 <10-6 Night-time bandwidth (nm) ~1.0 ~1.0 ~1.0 Daytime bandwidth (nm) ~ 0.5 ~ 0.5 ~ 0.5 Trasmission efficiency ~ 60% ~ 60% ~ 33%
CNR-IMAA Water vapour Raman Lidar
WG1 Workshop WaVaCS – Lindenberg 21 -23 May 2008
3
87th AMS Annual Meeting
Measurements
Operative since May 2002
2 measurements per week are systematically performed
Since November 2006 systematic measurements performed with
PEARL (Potenza EARlinet lidar)
Involvements
Validation of ENVISAT/MIPAS water vapour product
NDACC (The Network for the Detection of Atmospheric Composition
Change) for UT/LS water vapour monitoring
Measurements Campaigns
EAQUATE campaign (6-10 September 2004)
LAUNCH campaign (September – October 2005)
CNR-IMAA Water vapour Raman Lidar
WG1 Workshop WaVaCS – Lindenberg 21 -23 May 2008
87th AMS Annual Meeting
Water Vapor profiles characteristics
CNR-IMAA Water vapour Raman Lidar
Night time measurements
60 m – 12000 m a.l.s.
15-150 m vertical resolution
10 minutes temporal resolution
Daytime measurements
90 m – 4500 m a.l.s.
15 m vertical resolution
10 minutes temporal resolution
0
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1E-3 0.01 0.1 1 10
Lidar 19:48-19:57 UT Sonda 19:52 UT
Alti
tude
a.s.
l. (k
m)
Water vapor mixing ratio (g/kg)
11 November 2002
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-1 0 1 2 3 4 5 6 7 8 9 10Water Vapor Mixing Ratio (g/kg)
Alti
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Lidar 12:07-12:17 UT Sonde start 12:12 UT
02 October 2005
WG1 Workshop WaVaCS – Lindenberg 21 -23 May 2008
87th AMS Annual Meeting
CNR-IMAA Water vapour Raman Lidar
WG1 Workshop WaVaCS – Lindenberg 21 -23 May 2008
● Routine comparisons with numerical models (CloudNET)
● Long time series of measurements (campaigns, special events)
● Improvement of model parameterization
87th AMS Annual Meeting
CNR-IMAA Water vapour Microwave profiler
Courtesy of Radiometrics Corporation, Boulder, CO, USA
The microwave profiler measures the sky brightness temperature at 12 frequencies:
5 frequencies are in the K-band (22.235, 23.0335, 23.835, 26.235, 30 GHz), around 22 GHz water vapour resonance band;
7 frequencies are in the V-band (51.250, 52.280, 53.850, 54.940, 56.660, 57.290, 58.800 GHz), around 60 GHz spyn-rotation oxygen band.
Rate: > 12 sAccuracy: 0.5 KResolution: 0.25 KRange: 0 -700 KOperational range: -20° - 50° CScanning capabilities: 3D skyBeam width: 6.3° at 22.2 GHz, 4.9° at 30 GHz, 2.5° at 51.3 GHz and 2.4° at 58.8 GHz (full width half power)
Output products (Neural network retrieval)Temperature, water vapour, relative humidity and cloud liquid water profiles up to 10 km above the ground
Vertical step: 100 m from 0 to 1 km, 250 m above up to 10 km
Ancillary parameters.Cloud base temprature measured using an infrared thermometer (IRT).Surface meterological parameters (T, RH, p)
The microwave profiler measures the sky brightness temperature at 12 frequencies:
5 frequencies are in the K-band (22.235, 23.0335, 23.835, 26.235, 30 GHz), around 22 GHz water vapour resonance band;
7 frequencies are in the V-band (51.250, 52.280, 53.850, 54.940, 56.660, 57.290, 58.800 GHz), around 60 GHz spyn-rotation oxygen band.
Rate: > 12 sAccuracy: 0.5 KResolution: 0.25 KRange: 0 -700 KOperational range: -20° - 50° CScanning capabilities: 3D skyBeam width: 6.3° at 22.2 GHz, 4.9° at 30 GHz, 2.5° at 51.3 GHz and 2.4° at 58.8 GHz (full width half power)
Output products (Neural network retrieval)Temperature, water vapour, relative humidity and cloud liquid water profiles up to 10 km above the ground
Vertical step: 100 m from 0 to 1 km, 250 m above up to 10 km
Ancillary parameters.Cloud base temprature measured using an infrared thermometer (IRT).Surface meterological parameters (T, RH, p)
WG1 Workshop WaVaCS – Lindenberg 21 -23 May 2008
87th AMS Annual Meeting
CNR-IMAA Water vapour Microwave profilerMeasurements
Operative since February 2004
Continuous measurements (24h, 7 days per week)
Involvements
CloudNET
Departement of the Italian Civil Protection
Measurements Campaigns
EAQUATE campaign (6-10 September 2004)
LAUNCH campaign (Ziegendorf, Germany, August – October 2005)
COPS (Hornisgrinde, Germany, June – August 2007)
WG1 Workshop WaVaCS – Lindenberg 21 -23 May 2008
87th AMS Annual Meeting
CNR-IMAA Water vapour Microwave profiler
WG1 Workshop WaVaCS – Lindenberg 21 -23 May 2008
87th AMS Annual Meeting
• Comparisons with numerical prediction models (DWD- Lokall Modell) are routinely performed.
• Operational measurements (special scanning strategies)• Intercomparison campaign
CNR-IMAA Water vapour Microwave profiler
WG1 Workshop WaVaCS – Lindenberg 21 -23 May 2008
87th AMS Annual Meeting
Comparisons
WG1 Workshop WaVaCS – Lindenberg 21 -23 May 2008
● Differences in the resolution
● Microwave continuous measurements
● Possible synergies and integration LIDAR – Microwave profiler
87th AMS Annual Meeting
The IPWV retieved using the neural network algorithm is used to caiibrate the water
vapour Raman lidar profile
Calibration
• Calibration factor results constant within 5%
Vaisala radiosonde RS80, RS90 and RS92 PTU measurements (also wind speed/direction for RS92)
Calibration campaigns with co-located radiosondes
More than 200 radiosonde launches since May 2002
Calibration is checked systematically with radiosondes
1100 1200 1300 1400 1500 1600 17000.0
0.5
1.0
1.5
2.0
2.5
3.0CNR-IMAA 09 September 2004
Wat
er V
apor
Col
umna
r C
onte
nt (c
m)
Minutes of the day
Radiometer Lidar
Continuous monitoring of Raman lidar calibration
constant stability
MICROWAVE PROFILER
RADIOSONDE
WG1 Workshop WaVaCS – Lindenberg 21 -23 May 2008
87th AMS Annual Meeting
Case study: 30 Sep – 03 Oct 2005
๏ Presence of a dry intrusion around 5 km a.g.l.
๏ Minimum penetration level 2.5 km a.g.l. with a minimumvalue of the WVMR of 0.16 g/kg and a corresponding RH of 16 %.
๏ Strong uplift of moisture structures up to 7.5 km a.g.l. after the passage of the intrusion
WG1 Workshop WaVaCS – Lindenberg 21 -23 May 2008
87th AMS Annual Meeting
• Intrusion of a dry layer coming from about 5.5 km a.g.l. and moving down to less than 2 km on 2 October 2005.
• At 00:00 UTC on 2 October, the lidar resolves three distinct dry layers. • The highest layer is characterized by a minimum WVMR of 0.18 g/kg and a
maximum penetration level of 1.75 km a.g.l. where a WVMR value of 0.46 g/kg is measured.
Case study: 30 Sep – 03 Oct 2005
WG1 Workshop WaVaCS – Lindenberg 21 -23 May 2008
87th AMS Annual Meeting
• Images from the VISSR (on board of Meteosat) water vapour channel at 5.7 -7.1 µm for 28 September 2005 (a), 29 September 2005 (b), 30 September 2005 (c) and 1 October 2005 (d) at 06:00 UTC (Courtesy of University of Dundee).
Case study: 30 Sep – 03 Oct 2005
WG1 Workshop WaVaCS – Lindenberg 21 -23 May 2008
87th AMS Annual Meeting
Integration techniques• Kalman filter integration MODULAR scheme
TIME UPDATE
RTM
SOEKF LIDAR SOEKF MWP
FINAL GUESS
RH (MWP)
FIRST GUESS
WG1 Workshop WaVaCS – Lindenberg 21 -23 May 2008
● Low time consuming
● Second-Ordereffects in the retrieval
● Expansion to other profilers
87th AMS Annual Meeting
Integration techniques• Extended Kalman filter integration (1 Filter)
TIME UPDATE
RTM
FOEKF MEAS. UPDATE
FINAL GUESS
RH (MWP)
FIRST GUESS
F. MADONNA, C. CORNACCHIA, G. D'AMICO, L. MONA, A. AMODEO, and G. PAPPALARDO, Integration of Raman lidar and microwave profling measurements of water vapor using the Kalmanfiltering, in preparation.
WG1 Workshop WaVaCS – Lindenberg 21 -23 May 2008
● High time consuming
● Integration
● Expansion to other profilers – Higher computational burden
● Technique to reduce the burden
87th AMS Annual Meeting
Work in progress…..
• COPS (Intensive scanning measurements)
• CloudNET (Raman lidar, microwave profiler, ceilometer)
• EuroClouds proposal
WG1 Workshop WaVaCS – Lindenberg 21 -23 May 2008
87th AMS Annual Meeting
ThankThank youyou
WG1 Workshop WaVaCS – Lindenberg 21 -23 May 2008
87th AMS Annual Meeting
• Potential vorticity at 300 hPa surface (in PVU, 1 PVU = 10−6 m2 s−1 K kg−1) on 28 September 2005 at 06:00 UTC from 31-level ECMWF analysis with 1.125° resolution.
Case study: 30 Sep – 03 Oct 2005
WG1 Workshop WaVaCS – Lindenberg 21 -23 May 2008
87th AMS Annual Meeting
Case study: 30 Sep – 03 Oct 2005
Interpolated time series of the potential temperature retrieved using the pressure and temperature profiles measured with the radiosoundingsperformed at Lindenberg observatory on 30 September 2005.
WG1 Workshop WaVaCS – Lindenberg 21 -23 May 2008
87th AMS Annual Meeting
Integration: preliminary resultsCASE I: 26-27/02/2006 (Night time)
WG1 Workshop WaVaCS – Lindenberg 21 -23 May 2008
87th AMS Annual Meeting
Synergy
17.24.47 17.49.47 18.14.47 18.39.46 19.04.453
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ud B
ase
(km
)
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Integrated Liquid Water (m
m)
18:02 18:12 18:22 18:32 18:42 18:52 19:020
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Optical D
ept @355 nm
Lida
r R
atio
(sr)
Time (UT)
LR OD
Optical depth in the last 10 minutes is 0.03
The time variation of the lidarratio can be correlated to the cloud phase next to its base.
WG1 Workshop WaVaCS – Lindenberg 21 -23 May 2008
87th AMS Annual Meeting
18:00 18:20 18:40 19:000.00
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LWC
(mm
) - O
D
Time UTC
NN+IRT NN+LIDAR OD
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IRT PEARL
Clo
ud B
ase
Hei
ght (
m a
.s.l)
Time UTC
Synergy
WG1 Workshop WaVaCS – Lindenberg 21 -23 May 2008
Temperature – 20 June 2007
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ght (
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.s.l)
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MP3014 RS05:52
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MP3014 RS05:52
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MP3014 RS07:52
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MP3014 RS11:12
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.s.l)
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MP3014 RS11:12
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ght (
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.s.l)
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MP3014 RS16:57
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ght (
m .a
.s.l)
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MP3014 RS16:57
Temperature – 24 August 2007
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eigh
t (m
.a.s
.l)
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MP3014 RS 05:32
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MP3014 RS 10:58
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Humidity – Models (15 July 2007)Met Office NAE (North Atlantic and European) model
MP3014 CNR-IMAA microwave profiler
Humidity – Models (20 July 2007)
MP3014 CNR-IMAA microwave profiler
Met Office NAE (North Atlantic and European) model
Humidity – Models (01 August 2007)Met Office NAE (North Atlantic and European) model
MP3014 CNR-IMAA microwave profiler
87th AMS Annual MeetingWG1 Workshop WaVaCS – Lindenberg 21 -23 May 2008
87th AMS Annual Meeting
CLOUDNET MODELS
The EU CloudNET project offers an extended database of water
vapor profiles provided by five operational forecast models of
ECMWF, the MetOffice, MeteoFrance, KNMI and DWD.
Cloudnet is an European pilot network of stations for
clouds profiles observation.
Horizontal Resolution Temporal Resolution Level Number Forecast Time
DWD 7km 1h 35 t-12
ECMWF 40km 1h 60 t-12
MeteoFrance 25km 1h 41 t-12
MetOfficeGlobal 60km 3h 38 t
SMHI L24 44km 1h 24 t-12
SMHI L40 44km 1h 40 t-12
87th AMS Annual Meeting
COMPARISON APPROACH
1. Lidar high resolution profiles are reduced into a large grid boxes: vertical and
temporal resolution are reduced to those of the model
2. The new time grid is calculated on the base of wind speed to take into account
the advection time.
3. Only lidar data with a total error less than 20% are considered.
Long record of measurements (about 30 hours) has been collected at CNR-
IMAA on 1-3 October 2005, during the LAUNCH 2005 international campaign,.
87th AMS Annual Meeting
COMPARISON APPROACH - AN EXAMPLELidar at ECMWF model gridLidar at ECMWF model grid
ECMWF model dataECMWF model data
Lidar at MeteoFrance model gridLidar at MeteoFrance model grid
MeteoFrance model dataMeteoFrance model data
87th AMS Annual Meeting
COMPARISON APPROACH - AN EXAMPLE
More quantitative comparison can be carried out in terms of the probability
density function (pdf) calculated for both models and lidar data reduced at
models resolutions in different altitude ranges.
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Freq
uenc
y of
Occ
uren
ces
Freq
uenc
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uren
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Water Vapor Mixing Ratio (g/kg)
0-2 km of Altitude
Meteofrance model
Lidar Measurements
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Water Vapor Mixing Ratio (g/kg)
0-2 km of Altitude
ECMWF model
Lidar Measurements
ECMWF modelECMWF model MeteoFrance modelMeteoFrance model
87th AMS Annual Meeting
LONG TERM COMPARISON
Sistematic comparison has been perfomed between lidar data
and models.
1 comparison per month is carried for September 2002 –
February 2006 period.
The longest measurements run is chosen for each month.
Models and lidar data reduced at models grid are collected for
different altitude ranges.
Lidar and models Pdf are compared for 0-2 km, 2-4 km, 4-6
km, 6-8 km altitude ranges.
87th AMS Annual Meeting
LONG TERM COMPARISON – ECMWF
0 2 4 6 8 100.0
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Water Vapor Mixing Ratio (g/kg)
4-6 km4-6 km 6-8 km6-8 km
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uenc
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occ
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uenc
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Water Vapor Mixing Ratio (g/kg)
0-2 km0-2 km
3 modes are sligthly shifted in
ECMWF
0 2 4 6 8 100.000.050.100.150.200.250.300.350.40 0 2 4 6 8 100.00
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Water Vapor Mixing Ratio (g/kg)
2-4 km2-4 km
Higher values occurrences
underestimated by ECMWF
Pdf shape is generally well reconstructed in each interval
range
87th AMS Annual Meeting
LONG TERM COMPARISON – 6-8 km Altitude Range
0 1 2 3 4 5 60.0
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Water Vapor Mixing Ratio (g/kg)
0 1 2 3 4 5 60.0
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uenc
y of
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smhi L40 model
Freq
uenc
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occ
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ces
Water Vapor Mixing Ratio (g/kg)
0 1 2 3 4 5 60.0
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uenc
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occ
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Freq
uenc
y of
occ
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ces
Water Vapor Mixing Ratio (g/kg)
0 1 2 3 4 5 60.0
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Freq
uenc
y of
occ
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MetOfficeGlobal model
Freq
uenc
y of
occ
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Water Vapor Mixing Ratio (g/kg)
MetOfficeMetOffice SMHI L40SMHI L40
DWDDWD MeteoFranceMeteoFrance
Pdf well reconstructed, but larger pdf for observated wv high
values
87th AMS Annual Meeting
LONG TERM COMPARISON – 4-6 km Altitude Range
0 2 4 6 8 100.00
0.05
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0.30 0 2 4 6 8 100.000.050.100.150.200.250.300.350.40 Lidar Measurements
Freq
uenc
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occ
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occ
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Water Vapor Mixing Ratio (g/kg)
DWDDWD
0 2 4 6 8 100.0
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Freq
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occ
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MeteoFrance model
Freq
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occ
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Water Vapor Mixing Ratio (g/kg)
0 2 4 6 8 100.0
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Freq
uenc
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MetOfficeGlobal model
Freq
uenc
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occ
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ces
Water Vapor Mixing Ratio (g/kg)0 2 4 6 8 10
0.0
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Freq
uenc
y of
occ
uren
ces
smhi L40 model
Freq
uenc
y of
occ
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ces
Water Vapor Mixing Ratio (g/kg)
MetOfficeMetOffice SMHI L40SMHI L40
MeteoFranceMeteoFrance
Pdf well reconstructed, but larger pdf for observated wv high
values
87th AMS Annual Meeting
LONG TERM COMPARISON – 2-4 km Altitude Range
0 2 4 6 8 100.00
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0.30 0 2 4 6 8 100.00
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Freq
uenc
y of
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DWD model
Freq
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occ
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ces
Water Vapor Mixing Ratio (g/kg)0 2 4 6 8 10
0.000.050.100.150.200.250.300.350.40 0 2 4 6 8 100.00
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Freq
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MeteoFrance model
Freq
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occ
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Water Vapor Mixing Ratio (g/kg)
0 2 4 6 8 100.00
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MetOfficeGlobal model
Freq
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occ
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Water Vapor Mixing Ratio (g/kg)0 2 4 6 8 10
0.00
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Freq
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smhi L40 model
Freq
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occ
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Water Vapor Mixing Ratio (g/kg)
DWDDWD
MetOfficeMetOffice SMHI L40SMHI L40
MeteoFranceMeteoFrance
Pdf shape well reconstructed
2 modes observed
DWD overestimates the center of 2nd mode
Observed values in 0-8 g/kg range
Model underestimatesoccurrences of high values
87th AMS Annual Meeting
LONG TERM COMPARISON – 0-2 km Altitude Range
0 2 4 6 8 100.00
0.05
0.10
0.15
0.20
0.25
0.30 0 2 4 6 8 100.00
0.05
0.10
0.15
0.20
0.25
0.30 Lidar Measurements
Freq
uenc
y of
occ
uren
ces
DWD model
Freq
uenc
y of
occ
uren
ces
Water Vapor Mixing Ratio (g/kg)0 2 4 6 8 10
0.00
0.05
0.10
0.15
0.20 0 2 4 6 8 100.00
0.05
0.10
0.15
0.20 Lidar Measurements
Freq
uenc
y of
occ
uren
ces
MeteoFrance model
Freq
uenc
y of
occ
uren
ces
Water Vapor Mixing Ratio (g/kg)
0 2 4 6 8 100.00
0.05
0.10
0.15
0.20 0 2 4 6 8 100.00
0.05
0.10
0.15
0.20 Lidar Measurements
Freq
uenc
y of
occ
uren
ces
MetOfficeGlobal model
Freq
uenc
y of
occ
uren
ces
Water Vapor Mixing Ratio (g/kg)0 2 4 6 8 10
0.00
0.05
0.10
0.15
0.20 0 2 4 6 8 100.00
0.05
0.10
0.15
0.20 Lidar Measurements
Freq
uenc
y of
occ
uren
ces
smhi L40 model
Freq
uenc
y of
occ
uren
ces
Water Vapor Mixing Ratio (g/kg)
DWDDWD
MetOfficeMetOffice SMHI L40SMHI L40
MeteoFranceMeteoFrance
Fair agreement, but large differences for each model exist.
87th AMS Annual Meeting
PRELIMINARY RESULTS
Pdf is well reconstructed even if data show also
higher wv values that models do not forecast
Fair agreement in terms of pdf, but
large differences for each model exist.
0-2 km altitude range
4-6 km and 6-8 km altitude ranges
2-4 km altitude range
Pdf shape is well reconstructed.
2 modes are observed on DWD grid, but DWD
overestimates the 2nd mode center.
MeteoFrance and ECMWF underestimate
occurrences of values > 2 g/kg
87th AMS Annual Meeting
FUTURE PLANS
Investigation of possible seasonal behavior of
differences in model/observed data
Classification of data in cases with and without Free
Troposphere humid layers
Extending comparison dataset adding further data