microwave profiler: comparisons and synergies

Water vapour Raman lidar and microwave profiler: comparisons and synergies F. Madonna, A. Amodeo, C. Cornacchia, G. D Amico, L. Mona, G. Pappalardo Istituto di Metodologie per l Analisi Ambientale CNR-IMAA, Potenza, Italy

CNR-IMAA Water vapour Raman Lidar M M M = mirror P = pinhole L = collimation lens DM = dichroic mirror LASER: Nd:YAG laser (Coherent Infinity) Max. Pulse Energy@ 355nm 170mJ Maximum repetition rate 100Hz Beam divergence <0.3 mrad Pulse duration 3 4 ns BS = beam splitter PMT = photomultiplier IF IF = interferential filter RECEIVING SYSTEM: Cassegrain telescope Primary mirror diameter 0.5 m Combined focal length 5 m Night-time field of view 1 2 mrad Daytime field of view mrad M IF 386 nm PMT SPECTRAL SELECTION: interferential filter 355 nm P L M M BS IF 386 nm IF 355 nm PMT PMT 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 3 ~ 0.5 Trasmission efficiency ~ 60% ~ 60% ~ 33% M DM DM BS IF 355 nm PMT DETECTORS: photomultiplier THORN EMI 9202 QB355, 386, 407 nm Nd:YAG Laser BS IF 407 nm IF 407 nm PMT PMT ACQUISITION: photon counting mode EG&G MCS - PCI Minimum dwell time 100 ns Bandwidth 150 MHz PHILLIPS SCIENT. Fast discriminator Bandwidth 300 MHz

CNR-IMAA Water vapour Raman Lidar 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 Water Vapor profiles characteristics Night time measurements Daytime measurements 60 m 12000 m a.l.s. 90 m 4500 m a.l.s. 15-150 m vertical resolution 15 m vertical resolution 10 minutes temporal resolution 10 minutes temporal resolution 12 6 Lidar 12:07-12:17 UT Sonde start 12:12 UT 10 5 Altitude a.s.l. (km) 8 6 4 11 November 2002 Altitude a.s.l. (km) 4 3 2 2 Lidar 19:48-19:57 UT Sonda 19:52 UT 0 1E-3 1 1 10 Water vapor mixing ratio (g/kg) 1 0 02 October 2005-1 0 1 2 3 4 5 6 7 8 9 10

CNR-IMAA Water vapour Raman Lidar Routine comparisons with numerical models (CloudNET) Long time series of measurements (campaigns, special events) Improvement of model parameterization

CNR-IMAA Water vapour Microwave profiler The microwave profiler measures the sky brightness temperature The microwave profiler measures the sky brightness temperature at 12 frequencies: at 12 frequencies: 5 frequencies are in the K-band (22.235, 23.0335, 23.835, 5 frequencies are in the K-band (22.235, 23.0335, 23.835, 26.235, 30 GHz), around 22 GHz water vapour resonance band; 26.235, 30 GHz), around 22 GHz water vapour resonance band; 7 frequencies are in the V-band (51.250, 52.280, 53.850, 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 spynrotation oxygen band. 54.940, 56.660, 57.290, 58.800 GHz), around 60 GHz spynrotation oxygen band. Rate: > 12 s Rate: > 12 s Accuracy: 0.5 K Accuracy: 0.5 K Resolution: 5 K Resolution: 5 K Range: 0-700 K Range: 0-700 K Operational range: -20-50 C Operational range: -20-50 C Scanning capabilities: 3D sky Scanning capabilities: 3D sky Beam width: 6.3 at 22.2 GHz, 4.9 at 30 GHz, Beam 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) 2.5 at 51.3 GHz and 2.4 at 58.8 GHz (full width half power) Output products (Neural network retrieval) Output products (Neural network retrieval) Temperature, water vapour, relative humidity and cloud liquid Temperature, water vapour, relative humidity and cloud liquid water profiles up to 10 km above the ground 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 Vertical step: 100 m from 0 to 1 km, 250 m above up to 10 km Ancillary parameters. Ancillary parameters. Cloud base temprature measured using an infrared thermometer Cloud base temprature measured using an infrared thermometer (IRT). (IRT). Surface meterological parameters (T, RH, p) Surface meterological parameters (T, RH, p) Courtesy of Radiometrics Corporation, Boulder, CO, USA

CNR-IMAA Water vapour Microwave profiler Measurements 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)

CNR-IMAA Water vapour Microwave profiler

CNR-IMAA Water vapour Microwave profiler Comparisons with numerical prediction models (DWD - Lokall Modell) are routinely performed. Operational measurements (special scanning strategies) Intercomparison campaign

Comparisons Differences in the resolution Microwave continuous measurements Possible synergies and integration LIDAR Microwave profiler

Calibration RADIOSONDE 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 MICROWAVE PROFILER Continuous monitoring of Raman lidar calibration constant stability The IPWV retieved using the neural network algorithm is used to caiibrate the water vapour Raman lidar profile Water Vapor Columnar Content (cm) 3.0 2.5 2.0 1.5 1.0 0.5 CNR-IMAA 09 September 2004 Radiometer Lidar Calibration factor results constant within 5% 1100 1200 1300 1400 1500 1600 1700 Minutes of the day

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 minimum value of the WVMR of 6 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 87th AMS Annual Meeting WG1 Workshop WaVaCS Lindenberg 21-23 May 2008

Case study: 30 Sep 03 Oct 2005 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 8 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 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). 87th AMS Annual Meeting WG1 Workshop WaVaCS Lindenberg 21-23 May 2008

Integration techniques Kalman filter integration MODULAR scheme FIRST GUESS TIME UPDATE Low time consuming SOEKF LIDAR RTM FINAL GUESS SOEKF MWP Second-Order effects in the retrieval Expansion to other profilers RH (MWP)

Integration techniques Extended Kalman filter integration (1 Filter) FIRST GUESS TIME UPDATE RTM FOEKF MEAS. UPDATE FINAL GUESS RH (MWP) High time consuming Integration Expansion to other profilers Higher computational burden Technique to reduce the burden 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 Kalman filtering, in preparation.

Work in progress.. COPS (Intensive scanning measurements) CloudNET (Raman lidar, microwave profiler, ceilometer) EuroClouds proposal

Thank you

Case study: 30 Sep 03 Oct 2005 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. 87th AMS Annual Meeting WG1 Workshop WaVaCS Lindenberg 21-23 May 2008

Case study: 30 Sep 03 Oct 2005 Interpolated time series of the potential temperature retrieved using the pressure and temperature profiles measured with the radiosoundings performed at Lindenberg observatory on 30 September 2005.

Integration: preliminary results CASE I: 26-27/02/2006 (Night time)

Synergy 50 40 LR OD 3.0 2.5 Lidar Ratio (sr) 30 20 2.0 1.5 1.0 0.5 Optical Dept @355 nm Optical depth in the last 10 minutes is 3 10 0 18:02 18:12 18:22 18:32 18:42 18:52 19:02-0.5 Time (UT) 0.3 8 The time variation of the lidar ratio can be correlated to the cloud phase next to its base. Cloud Base (km) 7 6 5 4 Integrated Liquid Water (mm) 3 17.24.47 17.49.47 18.14.47 18.39.46 19.04.45 Time (UT)

Synergy 9500 9000 IRT PEARL Cloud Base Height (m a.s.l) 8500 8000 7500 7000 6500 6000 18:00 18:20 18:40 19:00 Time UTC 6 4 2 NN+IRT NN+LIDAR OD LWC (mm) - OD 0 8 6 4 2 0 18:00 18:20 18:40 19:00 Time UTC

Temperature 20 June 2007 8000 7000 MP3014 RS05:52 8000 7000 MP3014 RS05:52 8000 7000 MP3014 RS07:52 8000 7000 MP3014 RS07:52 6000 6000 6000 6000 Height (m.a.s.l) 5000 4000 3000 Height (m.a.s.l) 5000 4000 3000 Height (m.a.s.l) 5000 4000 3000 Height (m.a.s.l) 5000 4000 3000 2000 2000 2000 2000 1000 1000 1000 1000 0 225 250 275 300 325 Temperature (K) 0 225 250 275 300 325 Temperature (K) 0 225 250 275 300 325 Temperature (K) 0 225 250 275 300 325 Temperature (K) 8000 7000 MP3014 RS11:12 8000 7000 MP3014 RS11:12 8000 7000 MP3014 RS16:57 8000 7000 MP3014 RS16:57 6000 6000 6000 6000 Height (m.a.s.l) 5000 4000 3000 Height (m.a.s.l) 5000 4000 3000 Height (m.a.s.l) 5000 4000 3000 Height (m.a.s.l) 5000 4000 3000 2000 2000 2000 2000 1000 1000 1000 1000 0 225 250 275 300 325 Temperature (K) 0 225 250 275 300 325 Temperature (K) 0 225 250 275 300 325 Temperature (K) 0 225 250 275 300 325 Temperature (K)

Temperature 24 August 2007 6000 5000 MP3014 RS 05:32 6000 5000 MP3014 RS 07:56 6000 5000 MP3014 RS 10:58 Height (m.a.s.l) 4000 3000 2000 Height (m.a.s.l) 4000 3000 2000 Height (m.a.s.l) 4000 3000 2000 1000 1000 1000 0 250 275 300 Temperature (K) 0 250 275 300 Temperature (K) 0 250 275 300 Temperature (K) 6000 5000 MP3014 RS 13:56 6000 5000 MP3014 RS 17:01 Height (m.a.s.l) 4000 3000 2000 Height (m.a.s.l) 4000 3000 2000 1000 1000 0 250 275 300 0 250 275 300 Temperature (K) Temperature (K)

Humidity Models (15 July 2007) Met Office NAE (North Atlantic and European) model MP3014 CNR-IMAA microwave profiler

Humidity Models (20 July 2007) Met Office NAE (North Atlantic and European) model MP3014 CNR-IMAA microwave profiler

Humidity Models (01 August 2007) Met Office NAE (North Atlantic and European) model MP3014 CNR-IMAA microwave profiler

CLOUDNET MODELS Cloudnet is an European pilot network of stations for clouds profiles observation. 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. 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 EXAMPLE Lidar at ECMWF model grid Lidar at MeteoFrance model grid ECMWF model data MeteoFrance 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. Frequency of Occurences Frequency of Occurences 0 1 2 3 4 5 6 7 8 9 10 0-2 km of Altitude ECMWF model Lidar Measurements ECMWF model 0 1 2 3 4 5 6 7 8 9 10 Frequency of Occurences Frequency of Occurences 0 1 2 3 4 5 6 7 8 9 10 0-2 km of Altitude MeteoFrance model Lidar Measurements Meteofrance model 0 1 2 3 4 5 6 7 8 9 10 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 Lidar Measurements 5 0 5 0 0 0 2 4 6 8 10 5 0 5 ECMWF model 0-2 km 0 0 2 4 6 8 10 0 Lidar Measurements 5 0 5 2-4 km 0 0.40 0 2 4 6 8 10 0.35 ECMWF model 0.30 5 0 5 0 5 0 0 2 4 6 8 10 3 modes are sligthly shifted in ECMWF Higher values occurrences underestimated by ECMWF 0.30 Lidar Measurements 0.5 Lidar Measurements 5 0.4 0 5 4-6 km 0.3 6-8 km 0 5 0 0.5 0 2 4 6 8 10 0.7 0 1 2 3 4 5 6 0.4 ECMWF model 0.6 ECMWF model 0.5 0.3 0.4 0.3 0 2 4 6 8 10 0 1 2 3 4 5 6 Pdf shape is generally well reconstructed in each interval 87th AMS Annual Meeting range

LONG TERM COMPARISON 6-8 km Altitude Range DWD MeteoFrance 0.5 Lidar Measurements 0.4 0.3 0.5 0 1 2 3 4 5 6 DWD model 0.4 0.3 0 1 2 3 4 5 6 0.5 Lidar Measurements 0.4 0.3 0.7 0 1 2 3 4 5 6 0.6 MeteoFrance model 0.5 0.4 0.3 0 1 2 3 4 5 6 0.5 0.4 0.3 0.5 0.4 0.3 MetOffice 0.6 Lidar Measurements 0.6 0 1 2 3 4 5 6 MetOfficeGlobal model 0 1 2 3 4 5 6 0.6 Lidar Measurements 0.5 0.4 0.3 0.6 0.5 0.4 0.3 SMHI L40 0 1 2 3 4 5 6 smhi L40 model 0 1 2 3 4 5 6 Pdf well reconstructed, but larger pdf for observated wv high 87th AMS Annual Meeting values

LONG TERM COMPARISON 4-6 km Altitude Range DWD MeteoFrance 0.40 Lidar Measurements 0.35 0.30 5 0 5 0 5 0 0.30 0 2 4 6 8 10 5 DWD model 0 5 0 5 0 0 2 4 6 8 10 0.30 Lidar Measurements 5 0 5 0 5 0 0.5 0 2 4 6 8 10 0.4 MeteoFrance model 0.3 0 2 4 6 8 10 0.6 Lidar Measurements 0.5 0.4 0.3 0.6 0 2 4 6 8 10 0.5 0.4 0.3 MetOffice MetOfficeGlobal model 0 2 4 6 8 10 0.6 Lidar Measurements 0.5 0.4 0.3 0.6 0 2 4 6 8 10 0.5 0.4 0.3 SMHI L40 smhi L40 model 0 2 4 6 8 10 Pdf well reconstructed, but larger pdf for observated wv high 87th AMS Annual Meeting values

LONG TERM COMPARISON 2-4 km Altitude Range DWD MeteoFrance 0.30 Lidar Measurements 5 0 5 0 5 0 0.30 0 2 4 6 8 10 5 0 5 0 5 2 modes observed DWD overestimates the center of 2nd mode DWD model 0 0 2 4 6 8 10 0.30 Lidar Measurements 5 0 5 0 5 0 0.40 0 2 4 6 8 10 0.35 0.30 5 0 5 0 5 Observed values in 0-8 g/kg range Model underestimates occurrences of high values MeteoFrance model 0 0 2 4 6 8 10 0.30 Lidar Measurements 5 0 5 0 5 0 0.30 0 2 4 6 8 10 5 0 5 0 5 MetOffice MetOfficeGlobal model 0 0 2 4 6 8 10 0.30 Lidar Measurements 5 0 5 0 5 0 0.30 0 2 4 6 8 10 5 0 5 0 5 SMHI L40 smhi L40 model 0 0 2 4 6 8 10 87th AMS Annual Meeting Pdf shape well reconstructed

LONG TERM COMPARISON 0-2 km Altitude Range 0.30 Lidar Measurements 5 0 5 0 5 0 0.30 0 2 4 6 8 10 5 0 5 0 5 DWD DWD model 0 0 2 4 6 8 10 0 Lidar Measurements 5 0 5 0 0 0 2 4 6 8 10 5 0 5 MeteoFrance MeteoFrance model 0 0 2 4 6 8 10 0 Lidar Measurements 5 0 5 0 0 0 2 4 6 8 10 5 0 5 MetOffice MetOfficeGlobal model 0 0 2 4 6 8 10 0 Lidar Measurements 5 0 5 0 0 0 2 4 6 8 10 5 0 5 SMHI L40 smhi L40 model 0 0 2 4 6 8 10 Fair agreement, but large differences for each model exist. 87th AMS Annual Meeting

PRELIMINARY RESULTS 4-6 km and 6-8 km altitude ranges Pdf is well reconstructed even if data show also higher wv values that models do not forecast 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 0-2 km altitude range Fair agreement in terms of pdf, but large differences for each model exist. 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 87th AMS Annual Meeting