Mar 252015

The fellows from the ITaRS network met between March 18th-20th 2015 in Barcelona, at UPC (Universitat Politècnica de Catalunya).


The two first days were dedicated on a course about writing skills. Two lecturers from WAS gave us tips and advice to understand better the process of writing a scientific paper. The fellows had to prepare an abstract for a possible article in order to receive direct feedback to improve the understandability of this short text. The interactivity of the lectures made them very interesting. Important to mention is the powerful impact these advice can have on our future scientific publications.

The last day was consecrated to data assimilation. Two researchers from ECMWF (Reading, UK) came to introduce this concept. They explained how observations are useful and important in order to increase the predictability of the weather forecasts. The lectures were very interesting and the quality of their content was at very high scientific level.

MareNostrum3_supercomputer_UPCvisit of supercomputer UPC

We got the chance to visit some of the installations of UPC. We visited the building which houses the impressive supercomputer called MareNostrum (1 petaflop of speed!). The funny fact comes from the original use of this building: it was indeed a former chapel as you can see on the picture.

Finally, it was good to see again all the fellows. We managed to find time to discuss and speak about questions related to ITaRS. We also enjoyed a bit of the nice life of this pretty city.
Ole! 🙂

Mar 142015

On Wednesday 29th October 2014 was the official kick-off meeting of Waterlab which took place in the Science Center of TU Delft (link1, link2). Almost 300 pupils from primary schools of Delft had a first hint about science and rain measurements.

Currently, four primary schools in Delft area are involved in the project. The teachers and pupils measure local precipitations with handmade raingauges and compile all measurements to a dedicated website called MijnWaterlab. Besides these observations, rainfall intensities are also measured continuously since September 2014 with weather stations located in each of these schools (see picture on the right) in order to have a better idea about the variability of precipitation at the scale of a city. Easy comparisons can be made between each dataset.
On the other hand, in the upcoming weeks, students from secondary schools from Delft will integrate the project and the roof of these lyceums will be equipped with a station for measuring rainfalls. The students there will have to deal with scientific projects in relation with the analysis of these observations.


Since today, another weather station is also located in the Science Center to continue with the densification of the network of stations in Delft. The particularity of this station is that the data are collected automatically via wired internet connection with the use of a RaspberryPi-based system (see picture on the right) that was under development during the last months.
A quasi-similar configuration (using 3G wireless internet connection) will be applied very soon to the stations installed in schools (currently a visit to each school is needed to manually collect the data).

Nov 272014

In the last ITaRS Summer School on “Clouds and Precipitation: Observation and Processes”, which was held in the Jülich Research Center (Germany), the group working on the topic “When does a cloud form?” was selected as the one that made the best work in such a short period of time. The name of the group was “The Transformers” and the integrants were Elisa Adirosi (CNR-ISAC, Rome, Italy), Pilar Gumà-Claramunt (CNR-IMAA, Potenza, Italy), Lukas Pfitzenmaier (TU Delft, The Netherlands), Stefanos Samaras (University of Potsdam, Germany) and Veronika Wolf (DWD, Lindenberg, Germany)


The Transformers were awarded with the possibility to attend the meeting of TOPROF, the acronym of a COST Action standing for “Towards operational ground based profiling with ceilometers, doppler lidars and microwave radiometers for improving weather forecasts”, which was held in the DTU Risø Campus in Roskilde, Denmark. There, the students presented to the participants of the meeting the ITaRS project, the work they did during the Summer School, the Atmospheric Emitted Radiance Interferometer (AERI) instrument and their individual research projects. Furthermore, they attended many interesting talks, participated in the working groups meetings (ceilometers [WG1], Doppler lidars [WG2], Microwave radiometers [WG3] and/or Data assimilation [WG4]) and had the opportunity to discuss with experts in Remote Sensing of the atmosphere.

Finally, the three ITaRS students stayed one day after the meeting to visit Copenhagen

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We would like to thank ITaRS and TOPROF for the opportunity of attending this interesting experience.

Oct 312014

Today we went to Cabauw to fix some  radar issues that we have. The weather forecast of today was good for lidar measurements too we started the Raman-lidar CAELI as well. As you can see as all the measurement quick-looks for the lidar systems (Polly and CAELI) we had some nice cirrus layer over Cabauw. So we expected also that our colleagues from Munich would have a good change to observe some HALOs within the cirrus clouds. But the conditions where that good, that we could also observe this HALOs over Cabauw.

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Halos are optical reflections produced by hexagonal oriented ice crystals within ice clouds. This reflections produce a ring around the sun and also some bright dots next to the sun. Observations of such HALOs make it possible to get information about the ice crystal shape and their orientation. Lidar measurements could also give such information. Combining the measurements of the lidar systems and the HALO-camera in de Bilt will hopefully produce some nice results.


Oct 252014

Yesterday, Fr 24-10-2014, was a realy nice measurement day. A lot of mid-level clouds over Cabauw and all instruments where running and measuring smothly. Only the lidar systems where not able to penetrate the clouds, because of the precipitation that was present during the whole day. The overpassing front systems produced the whole day real nice clouds that we measured. To capture the vertical structure of the cloud system and the atmosphere we launched some radiosondes. So all in all we are happy that we could measure this clouds. With those information I wish a nice weekend!


Oct 232014

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The last days have been quite windy and rainy. That is also the reason why we didn’t spend so much time on the site. We launched some days ago some weather balloon. Such a radiosonde takes about 30 minutes of preparations before it is launched. First the balloon has to be filled with the right amount of Helium. Then the parachute attached and finally the sonde itself has to be tied up to the parachute. One important point to take into account before the launch is the wind speed and the direction. This prevents the sonde from being caught by trees or one cable of the Cabauw tower.

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With such a radiosonde it is possible to get vertical information about temperature, pressure, humidity and wind as the balloon is ascending in the atmosphere. This information help us to define thermodynamic conditions under which some of the microphysical processes can take place and some don’t. Several launches after each other also contain information about the variability of the atmospheric state. So all in all this small device is a real useful tool for our campaign.

Oct 232014

In July this year ATMOS group attended the 14th Conference on Cloud Physics and 14th Conference on Atmospheric Radiation which were held together in Boston. The conference is organised by the American Meteorological Society every 3 years. It is one of the biggest conferences in Cloud Physics and Radiation field.

We were presenting two posters:

  1. How Can We Use Lidar And Radar To Monitor Aerosol-Cloud Interaction? presented by Karolina Sarna
  2. The satellite observation of drizzle in Stratocumulus clouds presented by Igor Stepanov

If you are interested in the recordings from the Conference or Extended Abstracts, have a look here:


Oct 172014

On Monday, we had a visit form a photographer (Rob Doolaard) to shoot some pictures from our work there. Because of ‘bad’ weather conditions, we were most of the time inside one of the instrumental cabins to prepare our daily meeting and later on to also do the meeting. Actual plan had been, that we do lidar measurements and launch a weather balloon as well, but the conditions were too bad, so we skipped it. The first two pictures are taken inside the TARA radar cabi. The other two are outside during one of our discussions. They illustrate quite well, that a measurement campaign includes a lot of ‘IDLE state’ as well. And if the weather is not nice you wait inside 🙂

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Oct 122014

Now the first week is over already. It was an interesting one and we learned a lot from it.

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One thing is that hardware for wireless connection is not always waterproof. So we bought new ones and installed them and now everything works again. Network problems also costs us some missing of raw-data with TARA yesterday, but now everything seems to work again. The biggest issue we had so far is that both cloud radars stop working at the same. So right now we try to repair them with the support from METEK. One is already back and measuring. For the second on we hope to get it done soon.

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We also performed our first measurements with CAELI on Friday. We took almost 3 hours of measurements with it. At the beginning some low cumulus clouds were present. This made it difficult to align the lidar properly but after a short stop and a short readjustment it worked fine. Also in the afternoon the low cloud disappeared and we could measure the cirrus clouds.

All in all the first week was quite busy and I hope that the next weeks will be busy as well. But it would be nice to have less errors to fix and take more measurements instead.

Oct 092014

On the 7th of October we had a very nice Kick-Off. I think we all got a good impression about the campaign and about the clouds we want to observe. We all got wet around noon when a convective cell overpassed the site. But it desappeared as fast as it appeared. So thanks to Tim for giving us the nice pictures (the big ones in the middle). He took both pictures within less then 2 hours difference. With those to pictures you already can get an impression about how variable the weather was on the 7th of October over Cabauw.

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During this precipitation event one of the radars stopped working. This was fixed in the evening and it is now working continuously. But now one of our network connections is broken and we are working to fix that at the moment. The new equipment is bought and installed. And now waterproof!

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We also measured some nice clouds that morning, so the first data are taken. We hope for more nice and cloudy days like that morning. Now the sun is shining and we hope for a nice sunset later