Aug 012012

At the Cabauw Experimental Site for Atmospheric Research several active remote sensing instruments such as radar, lidar or sodar are placed. They monitor continuously particles in clouds and precipitation but also particles such as vulcanic ash, sea-salt or pollen.

The basis for these atmospheric measurements by radar, lidar or sodar is the active remote sensing equation. You can download here a presentation that introduces this fundamental equation which provides an analytical expression for the mean power received by an active remote sensing instrument.

Slide from the presentation with lidar/radar measurement examples
Jul 252012

Next week (30.07-03.08), ATMOS group will be attending the 16th International Conference on Clouds and Precipitation in Leipzig, Germany (ICCP2012)! We are presenting two posters on Monday and Wednesday within the sessions of: Basic cloud and precipitation physics and Convective clouds (including cloud electrification), by our researchers Igor Stepanov and Yann Dufournet.

 PNG image

Apart from the our scientific focus, we are eager to get acquainted with all of the ongoing clouds and precipitation related research! See you there!

Mar 272012

All data of 2011 from our weather radar IDRA can now be downloaded via the 3TU.Datacentre.
The data is freely available under the CESAR database policy.

Here are some of the events captured by IDRA in 2011 to illustrate the variety of data collected:

December 26th, 2011

IDRA reflectivity measurement of fog

Measurement of weak meteorological  echoes, possibly drizzle.

June 28th, 2011

IDRA Reflectivity measurement, 2011-06-28

Strong precipitation due to the passage of a cold front over the Netherlands.
Note the line of weak echoes close to the radar (in the center of this figure). This line is probably due to insects that are lifted in the air as a result of an up-draught.

June 27th, 2011

IDRA reflectivity measurement of insects        IDRA Doppler velocity measurement of insects

An IDRA measurement of insects. The figure on the right which shows the Doppler velocity measurement demonstrates that insects are a very good tracer for air motion.

Overall, the online available IDRA data for 2011 comprise:

  • data from 349 days,
  • during 554 hours IDRA measured moderate or strong precipitation echoes,
  • beside the processed data also 6863 raw data files are available.
Mar 132012


ePort – an interactive and user friendly layout of ground based and space borne atmospheric observations has found its way to the public. EUMeTrain project has made a large data quantity and weather analysis for Europe available online, updated every 6 hours. ePort is a product of EUMeTrain which is developed to allow you to combine a range of EUMETSAT satellite images with satellite derived
products and numerical model fields.

Project overview link –>

Go to last updated measurements now!

The principle goal of EUMeTrain is to provide users of EUMETSAT satellite data and products that will assist them to make more effective use of it, either as stand-alone material or in combination with other meteorological data sources. This is done by allowing the user to select the variable of interest and plot it for the selected domain/location with a single mouse click. It can be infra-red/visible channel of Meteosat Second Generations satellite, extreme weather warnings (ESTOFEX), 10 meter height wind speeds, CAPE (Convective Available Potential Energy), sounding data, vertical cross sections cloud cover, etc.

The project team consists of the national meteorological services of Austria (ZAMG), Croatia (DHMZ), Finland (FMI), Germany (DWD) and
Portugal (IM).

Mar 022012

An innovative Satellite Report format for synoptic/regional weather analysis, as observed using Meteosat Second Generation satellite imagers, has been introduced and hosted by the KNMI web site. Observed cloud pattens are explained and correlated to the regional scale atmosphere dynamics, such as: front positioning, jet streams, types of precipitation, cloud types identification, etc.

Link: —>

Initially started at the Austrian Meteorological Institute (ZAMG), SatRep project further developed with the co-operation of the European Meteorological Satellite Organisation EUMETSAT, the Netherlands Meteorological Institute (KNMI) and the Finnish Meteorological Institute (FMI).

SatRep can be used for nowcasting (weather forecasting in the coming 3-4 hours), and as an additional source of current/archive weather situation for the end user, compared to typical amount of information one can extract provided satellite images alone.

Dec 212010

Merry Christmas and the best wishes for the New Year to you!

IDRA radar measurement of the snowfall event in the morning hours of the 21st of December 2010

IDRA reflectivity measurement at Cabauw of the snowfall event in the morning of the 21st of December 2010, 3:00 – 6:30 UTC.
The TU Delft IRCTR drizzle radar (IDRA) is situated in the center of this so-called plan-position indicator, showing the horizontal spatial distribution of precipitation around Cabauw, The Netherlands, within a range of 15 km.

Snow at the Campus, TU Delft EWI-Faculty
TU Delft, Mekelpark, EWI Faculty

Snow in Delft, Oude Kerk
Delft, Oude Kerk

Nov 112010

In cooperation with the KNMI and other Dutch Organisations and Universities, TU Delft’s ATMOS group is participating at the Cabauw Experimental Site for Atmospheric Research – CESAR.

At Cabauw lots of measurement instruments are situated to continuously observe water in the atmosphere and on the ground, radiation, aerosols, and more. The data acquired is stored and freely accessible for scientific use via the CESAR database.

Near real-time displays of the measurements are also available online:

  • cloud video, cloud radar, ceilometer and more  » link,
  • meteorological tower data like wind, temperature and more » link,
  • CAELI lidar » link,
  • aerosol data » link,
  • IDRA radar »
  • TARA radar »
  • tropospheric emission monitoring internet service »

Here an impression of some real-time displays from CESAR:

 Cloud Camera
Cloud camera looking towards
the northern sky

Cloud Camera
Cloud camera looking towards
the western sky

 IDRA radar
10 GHz horizontally scanning radar IDRA

Cabauw Tower Observations
Tower Profiles 

 CT75 Ceilometer
Ceilometer, vertically pointing

 Vertical pointing 35GHz Cloudradar
35 GHz cloud radar, vertically pointing

 TARA reflectivity (dBZ)
3 GHz profiling radar TARA (reflectivity)
TARA Doppler velocity (ms-1)
3 GHz profiling radar TARA (Doppler velocity)
Mar 242010

IDRA reflectivity measurements from 2008 and 2009 are publicly available in NetCDF format in the CESAR database.

Beside the IDRA data, you will find in the CESAR database a large variety of atmospheric measurements carried out at Cabauw.

CESAR stands for Cabauw Experimental Site for Atmospheric Research. It is a consortium of eight institutes and universities from The Netherlands. The goal of the consortium is to operate and maintain with CESAR a unique observational facility with a comprehensive set of remote sensing and in-situ equipment to characterize the state of the atmosphere, its radiative properties and the interaction with the land surface.