cost-720 integrated ground-based remote sensing stations for atmospheric profiling

Geneva: Dec. [email protected] WMO / TECO – Dec 4 - 6, 2006

Richard-Aßmann Observatory, Lindenberg

COST-720Integrated Ground-Based Remote Sensing Stations for Atmospheric Profiling

Concept COST-720

Objectives + Structure Campaigns Major Results

Remote-sensing field site at Lindenberg Observatory

Dirk Engelbart (DWD), Wim Monna (KNMI), and John Nash (UKMO)



development of integrated ground-based remote-sensing stations for atmospheric profiling

Assessment of their use for meteorological analysis, forecast, climate research and monitoring

Set-up of networks of integrated profiling stations during dedicated campaigns

Goals of COST-720



Organisation - I

WG1, Basic Techniques and Algorithms

• Assessment of the state of the art of individual techniques in view of potential for integration

• Improvements where necessary and possible• Considered measurement systems:

- Microwave and IR Radiometer- water-vapour and Doppler wind Lidar- Wind profiling radar/RASS- Cloud radar- SPC ceilometer- C-Band weather radar.



Organisation - II

WG2, Integration

• Development / assessment of methods to derive

- Temperature profiles- Humidity profiles- Cloud characteristics- boundary-layer characteristics

from integrated remote sensing for different kinds of users



Field experiments:TUC

• Payerne, Switzerland• 15 November, 2003 – 15 February, 2004• In-situ & ground-based remote-sensing systems

Goals• Test of basic ground-

based T and U profiling

systems• Study ability to detect PBL phenomena• Assess automatic cloud detection systems• Provide dataset to study system integration

Instruments• 1290 MHz wind profiler• 78 GHz cloud radar• radiometers (ASMUWARA, Radiometrics, IR)• radiosondes (3 types)• ceilometer• GPS humidity system• total sky imager• BSRN instruments



Field experiments: TUC

Results: 10 reviewed papers published in a Special Issue «COST-720 TUC» of Met.Z.: Vol. 15, No. 1, 2006, 97pp.

• Intercomparisons found biases in both …. microwave radiometers all radiosondes’ humidity

• FMCW cloud radar can monitor fog base/top

• Radiometer and wind profiler able to monitor: T and humidity inversions near surface

• First integration of Wind Profiler and Microwave Radiometer for humidity profiling



Field experiments: CSIP

CSIP = “Convective Storm Initiation Project”Central-Southern England, June – August 2005COST-720 and UK Universities

• System integration studies for summertime PBL• High-resolution NWP modelling

Instruments:• Microwave radiometer• Laser ceilometer• 1290 MHz windprofiler• Chilbolton radar• Radiosondes



Field experiments: CSIP

Results• UHF radar can see lids of convective inhibition and

resolve structure of convective plumes• Radiometer IWV in good agreement with most GPS

sensors at high temporal resolution• Radar refractivity measurements can make humidity

changes• Cold Pools behind mesoscale convective systems• Analysis is ongoing...

See:• http://www.env.leeds.ac.uk/csip/



Field experiments: Helsinki Testbed

Helsinki Testbed (see: Poutiainen paper) Southern Finland, Finnish MetOffice, August 2005

(start) = permanent integrated profiling station

Provides data & experience for• Mesoscale weather research• Forecast- and dispersion-model development

Instruments• Finnish weather observation network• Vaisala WXT510 weather transmitter network (60)• 1.3 GHz windprofiler/RASS• Dual-polarization weather radar



(1) Assessment of new or improved humidity, temperature, and wind profiling systems profiling systems:

Water vapour Lidar systems (Raman Lidar and DIAL) Doppler wind Lidar vs WPR (ZIE) inter-comparison of different types of MWP systems FTIR spectrometer High-range SPC ceilometer

(2) Assessment of various algorithms, combining different techniques for profiling of cloud parameters (integrated profiling), in particular

LWC profiling Improved rain rate profiling by radar

(3) Provision of a data set, designed for validation and comparisons between measurements and NWP output,

(4) Provision of a data set for OSEs using 3D-/4D-VAR data assimilation for high-resolution WV-profiling systems in regional NWP modelling

3D-VAR / 4D-VAR MM5/ECMWF system of Hohenheim + of L‘Aquila (3D-VAR) NWP output validation using the FZK-IFU MM5 with a modified integration and

advection scheme

Field experiments: LAUNCH-2005 (see special poster)

(29th Aug. – 31st Oct, 2005)



LAUNCH-2005: Basic techniques

Improvement of microwave profiling(humidity & temperature)

Validation Dec.2004 – Nov.2005:

Bias & rms-error of T and U profiles (vs. RS) applying:

neural network

measurement-based regression(operational regr.)

Model-based regression method (training): - may improve profiling performance - allows easy use of MWP at all sites



Lidar: RAMSES data example: Sep 25/26, 2005


DWD RAMSES (Raman Lidar for Atmospheric Moisture SEnSing)

DWD - RAMSES

● automated operation, data acquisition, & evaluation

● at MOL-RAO now 15 months of test operation ● similar fully-autonomous systems are in test mode at Payerne and Cabauw

● commercial network systems below 150 k€ now available (COST-720 final workshop)



Lidar: RAMSES data example: Sep 25/26, 2005




Mean Z-R-relation over 30 hours“Large“ drop mode, 6 hours

LAUNCH-2005: Integrated Profiling

“Small“ drop mode, 8 hours

Rain ratesby

Weather Radar+

Micro-Rain Radar

Z/R relation (x-Band Rad.)

according to real DSD

DSD:• classified in modes• measured by MRR



European domain

Raman LidarDIALCloud Radar / MRRMicrowave Radiometer

Systems in the domain

14 Lidar systems (WV systems) 8 MWP systems (2 MW radiometer) 3 cloud radars (+1 MRR at Leipzig) 11 MRR (Validation) Ceilometers (Validation)

LAUNCH-2005:



23:00 00:00 02:0001:00Time UTC

Obs

erva

tion

ECM

WF

i.s.

4D-V

ar i.

s.

Hei

ght

asl

/ km

WV mixing ratioOct. 26/27, 2005

i.s. = initial state

LAUNCH-2005: Assimilation of WV lidar



LAUNCH-2005: Assimilation of WV lidar

4D-VAR



Water-vapour mixing ratio14.10., 1712 UTC - 15.10., 0511 UTC

RAMSES

MWP

LM

LAUNCH-2005: Validation of humidity modeling

Clouds



Cloud profiling(CloudNet cooperation)

Comparison Measurement - Model:

(Examp. Chilbolton vs. DWD-LM: Jan – Sep 04)

Freq. of LWCs in clouds

Obvious model deficits Strong model underestimation of LWC in low clouds

Model validation using Integrated profiling



Major Results of COST-720 / I(related to operational users)

(1) Basic techniques & algorithms- major improvements in microwave profiling (operationally applicable all-weather technique)

(2) Algorithms for system Integration- combination of MWP and WPR for improved humidity sounding- MWP, cloud radar, lidar, rain-gauge (CloudNet)- weather radar and MRR for improved rain rates from weather radar- MWP, cloud radar + lidar for profiling of cloud characteristics

(3) Proposals for system integrationa) Wind: compos.profiling using Sodar + WPRb) Temperature: RASS + MWPc) Humidity: MWP + WPR (WV Lidar for validation &

reference)d) Clouds: MWP, cloud radar, lidar (+ rain gauge)

(see Results-III) (IPT, radar-lidar method or CloudNet retrieval) …..still ongoing evaluations (LAUNCH, CSIP, Helsinki-Testbed)

……



Major Results of COST-720 / II(related to operational users)

(1) Results for NWP- definition and test of NetCDF data formats for MWP and Lidar humidity profiling- OSEs using WV-Lidar in data assimilation to NWP models clear impact for high data qualities- validation potential of NWP output (supply of reference quality for wind,

temperature, humidity profiles and cloud characteristics)

(1) New system developments related to COST-720:- hardware improvements of MWP systems enhanced all-weather capabilities- autonomous WV Raman-lidar systems in Lindenberg / in near future also

Cabauw(in 2007) and Payerne(early 2007)- commmercial Doppler-wind (100k€) and aerosol/humidity lidar (<150k€)

(1) Network stations for integrated profiling in Europe Lindenberg (GER), Payerne + Bern (CH), Palaiseau (Paris, F), L’Aquila + Rome + Potenza (I), Cabauw (NL), Camborne + Chilbolton (GB), Helsinki (FIN)



Major Results of COST-720 / III(related to operational users)

Integrated station for NWP validation / cloud profiling:

Instruments– Doppler cloud radar (Pulsed or FMCW / 94 or 35 GHz [less attenuation])– SPC Ceilometer or (real) Lidar– Dual-frequency microwave radiometer (23.8, 36.5 GHz / use ceilometer to help calibrate)– Rain gauge (drop counting rather than tipping bucket)

CLOUDNET has realized integration meanwhile: www.cloudnet.org• 4 remote-sensing sites (currently), 7 models (currently)• already provides yearly/monthly statistics for cloud fraction and

IWC / LWC including comparisons betw. observations & models

Algorithms (developed and/or assessed during COST-720)– Integrated profiling technique (IPT)– Radar-Lidar approach– CloudNet retrieval (classification)

cost-720 integrated ground-based remote sensing stations for atmospheric profiling

Documents