by Lukas Pfitzenmaier

Dear all,

In less than 8 days, a new measurement campaign (ACCEPT - Analysis of the Composition of mixed-phase Clouds with Extended Polarization Techniques) will take place at the CESAR observation site (Cabuw, The Netherlands). The TU Delft (Atmospheric remote sensing group of Geosince and Remote Senisn of TU Delft) and TROPOS (Leibniz Institute for Tropospheric Research - Leipzig, Germany) is greatly involved in it. On behalf of the campaign team, I would like to invite you all to the Kick-Off of the campaign which will be on Tuesday 7th October at the CESAR observatory in Cabauw, from 11:00 to 15:00.

ACCEPT flyer Kick off

During that day, a short presentation of the campaign objectives as well as a tour of the different instruments will be given. This is a great chance to get information about the extended instrumental setup that will be deployed during the campaign. All together TU Delft, TROPOS, the LMU (Ludwigs Maximillians Universities - Munich, Germany), Metek (Meteorologische Messtechnik GmbH - Elmshorn, Germany) and KNMI (Royal Dutch Weather Service – The Netherlands), are glad to be able to operate a set of state-of-the-art instruments for atmospheric measurements running at Cabauw.

In the following eight weeks we are going to focus on mixed-phase clouds measurements. Mixed-phase clouds are frequently observed in the atmospheric temperature range between -40 and 0 °C where cloud water droplets and ice crystals can coexist. The composition of these mixed-phase clouds, i. e., the partitioning of liquid water and ice, plays a crucial role in the formation of precipitation and in the cloud radiative effect. The precipitation of ice crystals through layers of super-cooled liquid water affects ice crystal growth and shape.

An instrumental setup composed of Raman lidars, cloud radars, precipitation radars, and microwave radiometers will be used in synergy in order to address this topic. To measure the dynamics we have a wind profiler and a Doppler lidar, the disdrometer measures the rain drop size distribution and radiosondes give information about the atmospheric conditions. We also have a HALO camera to characterise ice crystal shapes of cirrus clouds.

The different frequencies of the sensors allow us to study many different cloud process and retrieve in the end the cloud microphysics.

So we will make a tour through all the instruments, launch the first radiosonde and will have lots of time to talk and explain more details while having some food and drinks.

If you are interested please let us know before end of next week (Friday October 3rd) by sending an e-mail to This email address is being protected from spambots. You need JavaScript enabled to view it.">This email address is being protected from spambots. You need JavaScript enabled to view it. or This email address is being protected from spambots. You need JavaScript enabled to view it., that we can prepare all the food and drinks J

So, I hope to see many of you that day!