WEGN4CARE - Validation of EarthCARE cloud and precipitation products by
the WegenerNet 3D Open-Air Laboratory for Climate Change Research inSoutheastern Austria (EVID34)
Jürgen Fuchsberger1 (Co-I), Gottfried Kirchengast1,2 (PI), Ulrich Foelsche2,1 (Co-I)
Supported by the WEGN team members: Christoph Bichler1,2, Robert Galovic1
1) Wegener Center for Climate and Global Change (WEGC), University of Graz, Austria(Contact: juergen.fuchsberger@uni-graz.at; www.wegcenter.at)2) Institute for Geophysics, Astrophysics, and Meteorology/Institute of Physics, University of Graz, Austria

Online presentation @ 2nd ESA EarthCARE Validation Workshop, 25 May 2021

Further info on partners & sponsors: www.wegcenter.at/wegenernet

The WegenerNet 3D Open-Air Laboratory for Climate Change
Research (WEGN 3D) – Ground Station Network (WEGN 2D part)Key features of the WegenerNet ground station network:• Pioneering high-resolution network for long-term monitoringof weather and climate• 156 climate stations (red symbols in map) located in
the southeastern Alpine foreland in Austria• ~22 km x 16 km region• Station grid with a station every about 2 km²• Elevation range ~250 m to 600 m,• Highest station elevation: 520 m• More than 13 years of data (start: 1st January 2007)• Main parameters: Temperature, relative humidity, andprecipitation, measured at all stations• At 13 stations additional measurements of wind and solid
precipitation (heated rain gauges)• At 12 Stations soil moisture and soil temperature
measurements• Reference station additionally measures air pressure and net
radiation balance• Measurement sampling rate 1 min to 5 min• Data available at www.wegenernet.org

WEGN4CARE: J. Fuchsberger et al. – Wegener Center for Climate and Global Change

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WEGN 3D: Polarimetric X-Band precipitation radar Stradnerkogel
Location: Mount Stradnerkogel at 609 m
above mean sea level.
Output products: Rainfall intensity R(mm/h), Reflectivity Zh and Zv (dBZ), etc.

1 km x 1 km horizontal, 500 m vertical

2.5-min time sampling

Mounted on a 81 m tall radio mast,
about half-level, at 41 m height.

WEGN4CARE: J. Fuchsberger et al. – Wegener Center for Climate and Global Change

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WEGN 3D: Atmospheric profiling and cloud structure
microwave/IR radiometers
Location “Central Station Raabtal” (156):
Rooftop (~27 m above ground) of an officebuilding in the central valley of the regionOutput products: temperature, humidity, and cloud liquid water profiles;
integrated water vapor, liquid water path, cloud base height, for full sky
above the radiometer pair (angular resolution: 10° elev., 20° azim.)
10 min time sampling
Vertical grid resolution of <= 60 m in boundary layer (at < 1.5 km altitude)and <= 300 m in free troposphere (1.5 km to 10 km)

WEGN4CARE: J. Fuchsberger et al. – Wegener Center for Climate and Global Change4

WEGN 3D: GNSS six-station network “GNSS-StarNet”
Station locations:•156

6 Multi-GNSS stations within WegenerNet region (at WegenerNet
station no.s 11, 37, 77, 101, 139, 156), built and operated jointlywith the GFZ Potsdam (Prof. J. Wickert & Team)• Measuring slant and vertically integrated water vapor (IWV)columns above the WegenerNet area, with 2.5 min to 15 mintime resolution
Two star-shaped subnets:• „Main Star“: 5-star with ~10 km interstation distances,consisting of stations 11, 37, 77, 101, 139• „Embedded Star“: 4-star with ~5 km interstation distances,consisting of stations 11, 156, 77, 101• Station 156 (center of the Embedded Star) will be GRUAN1standard (Choke-ring antenna, collocatedtropospheric profiling radiometer measurements, etc.)

GNSS-StarNet “Main Star“
GNSS-StarNet “Embedded Star“
WEGN4CARE: J. Fuchsberger et al. – Wegener Center for Climate and Global Change

1Global Climate Observing System Reference Upper-Air Network(www.gruan.org).
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WEGN4CARE: EarthCARE validation aims and strategy
L2a, C-TC (Cloud Radar - Target Classification):• validate cloud base height against WEGN IRradiometer data (sufficient accuracy of 50 to 400 m
available up to 3000 m altitude)• validate simplified convective classification using
WEGN X-band weather radar data
• validate melting layer base and top heights in a
campaign-like setup of the WEGN X-band radar

L2b, ACM-CAP (Cloud and Aerosol properties):• validation using WEGN radiometer data
• liquid water content (LWC) (threshold: 50 g/m²LWP)• liquid water path (LWP) (threshold: 67 g/m²
for +-15 % accuracy)• validation using WEGN X-band weather radar andground precipitation data• rain rate (threshold: 0.1 mm/5 min)• rain water content• raindrop normalized number concentration(*)• median raindrop diameter(*)• rain classification• convective classification*for moderate to heavy precipitation;

Temporal collocation possible within < 1 min (campaign-wise) and < 5 min (operational).
WEGN4CARE: J. Fuchsberger et al. – Wegener Center for Climate and Global Change

6WegenerNet references and further information
Data portal: www.wegenernet.org
Homepage: www.wegcenter.at/wegenernet

Fuchsberger, J., G. Kirchengast, and T. Kabas (2021):WegenerNet high-resolution weather and climate data from 2007 to 2020,
Earth Syst. Sci. Data, 13, 1307–1334.
https://doi.org/10.5194/essd-13-1307-2021
O, S., U. Foelsche, G. Kirchengast, J. Fuchsberger, J. Tan, and W. A. Petersen(2017):
Evaluation of GPM IMERG Early, Late, and Final rainfall estimates using
WegenerNet gauge data in southeastern Austria, Hydrol. Earth Syst. Sci., 21,6559–6572
https://doi.org/10.5194/hess-21-6559-2017

WegenerNet Data DOI:
Fuchsberger J., G. Kirchengast, C. Bichler, A. Leuprecht, andT. Kabas (2021):
WegenerNet climate station network Level 2 data version 7.1(2007–2020), University of Graz, Wegener Center for Climate
and Global Change, Graz, Austria.
https://doi.org/10.25364/WEGC/WPS7.1:2021.1
Instrument provider information:
Precipitation radar: https://furuno-weather-radar.com
MW/IR Radiometer: https://www.radiometer-physics.de
IR Cloud Structure Radiometer: http://www.nubiscope.de
GNSS-StarNet infrastructure ops: https://www.gfzpotsdam.de/en/section/space-geodetictechniques/projects/gnss-infrastructure/

Kirchengast, G., T. Kabas, A. Leuprecht, C. Bichler, and H. Truhetz (2014):WegenerNet: A pioneering high-resolution network for monitoring weatherand climate. Bull. Amer. Meteor. Soc., 95, 227-242.
https://doi.org/10.1175/BAMS-D-11-00161.1
WEGN4CARE: J. Fuchsberger et al. – Wegener Center for Climate and Global Change

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X-Band precipitation radar: Case study of heavy precipitation on
29 June 2020
WEGN4CARE: J. Fuchsberger et al. – Wegener Center for Climate and Global Change

Animation of radar images (2020-06-29
10:29 – 12:02 UTC)

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X-Band precipitation radar: Case study of heavy precipitation on
29 June 2020
WEGN4CARE: J. Fuchsberger et al. – Wegener Center for Climate and Global Change

2nd highest 5-min precipitation rate on
WegenerNet record (since 2007):
20.6 mm/5 min at Station 66
42.0 mm/30 min, 58.2 mm/60 min, and76.8 mm/day

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X-Band precipitation radar: Case study of heavy precipitation on
29 June 2020

WEGN4CARE: J. Fuchsberger et al. – Wegener Center for Climate and Global Change

Animation of WegenerNet gridded
precipitation data:
June 29, 2020 10:45 – 12:00 UTC10

X-Band precipitation radar: Specifications and data products
Type Furuno WR-2120

Polarimetric X-band weather radar operating at ~9.4 GHz

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WEGN4CARE: J. Fuchsberger et al. – Wegener Center for Climate and Global Change

Output products: Rainfall intensity R (mm/h), Reflectivity Zh and Zv (dBZ),
Doppler velocity V (m/s), Doppler velocity width W (m/s), Cross polarizationdifference phase dp (deg), Specific differential phase KDP (deg/km),
Correlation coefficient between the two polarizations, Horizontal andVertical Differential reflectivity ZDR (dB)Further derived products: Hydrometeor classification,
drop size distributionNative resolution: 2.7° angular, 300 m radial
Resolution of processed 3D volume data:
1 km x 1 km horizontal, 500 m vertical

Observation range: 30 km (up to 70 km for case studies)

2.5-min time sampling (180° 3D volume; down to 30 s for case studies)Peak output power: 100 W

Advanced pulse compression techniques

Operating since May 202011

Atmospheric profiling and infrared radiometer: Specifications anddata products

Type: RPG-HATPRO-G5

Relative humidity and temperature profiling microwave/IR radiometerMulti-directional azimuth and elevation scanning

14 microwave channels (22 GHz to 31 GHz and 51 GHz to 58 GHz)IR radiometer at 9.6-11.5 μm bandVertical grid resolution of <= 60 m in boundary layer (at < 1.5 km altitude)and <= 300 m in free troposphere (1.5 km to 10 km)

Observation range: 0 m to 10000 m

10-min time sampling (for full 3D scene for chosen ops mode)

WEGN4CARE: J. Fuchsberger et al. – Wegener Center for Climate and Global Change

Output products: temperature, humidity, and cloud liquid water profiles;
integrated water vapor, liquid water path, cloud base height

Capable of GNSS satellite tracking for GNSS-line-of-sight integrated watervapor (IWV) observations
temperature profiling with an accuracy of ~0.5 K or better in boundary layerand ~1 K or better in free troposphererelative humidity profiling with an accuracy of ~5 % or better in the lower
troposphere (< 5 km altitude);12

Cloud structure infrared radiometer: Specifications and dataproducts

Type: NubiScope infrared cloud scanning radiometer

Enabling multi-layer cloud-field reconstruction over the WegenerNet area

Multi-directional azimuth and elevation scanningIR radiometer at 8-14 μm band

Output products: IR temperature of cloudless sky, cloud cover percentage,cloud type, cloud base height and temperature
10-min time sampling (for full 3D scene)

Nubiscope.eu

WEGN4CARE: J. Fuchsberger et al. – Wegener Center for Climate and Global Change

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GNSS-StarNet: Specifications and data products

Receiver type: Septentrio PolaRx5 FULL

Mapping of water vapor columns



15-min time sampling (slant total delays 2.5 min)

Main data products: Vertically Integrated Water Vapor [kg m2], Zenith Wet
Delay [mm], Zenith Total Delay [mm], Slant Total Delay [mm]Operated in cooperation with GFZ Potsdam, providing station monitoring andprocessing towards the main data products

Picture source: GFZ Potsdam

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