by Stefanos Samaras

Right after our summer school I (Stefanos Samaras) extended my stay to Bucharest to fulfill my secondment in INOE, Bucharest. My work there focused on two targets: 1) Extract the microphysics for spherical particles and 2) Improve the algorithm of Bucharest group for the calculation of the extinction coefficient profile.

A lot of work was done for the first part. Many runs of microphysical retrieval code gave us the chance to study not only the behavior of our algorithm for different set-ups (both from mathematical and physical point-of-view) but also compare it with the sun photometer- and AMS retrievals. Not every single run confirmed our expectation or physical intuition, and this is mostly due to the fact that very little information is used as an input (only 5 optical parameters) and that the automatized way to produce and restrict the solution space is not always trustworthy and has to be further verified by operator’s experience. In addition, I had the chance to watch closer the synergy between lidar systems and the AMS.

The second objective was approached by applying an algorithm of Potsdam group to range corrected lidar signals ofStefanos Bucharest group. A few modifications to the code had to be done first, for compatibility reasons and then run several tests for the inversion to derive the extinction coefficient profiles. Primary studies indeed showed some improvement for the exctinction retrieval. Furthermore an alternative way of discretising the problem was suggested. Still, this was a first contact with problem and a lot of tests are yet to be done.

The best part of this secondment was the “synergy” of people. Continuous group work combined with a nice environment made my stay here as fruitful as it could get. Best regards and a huge Thanks to Doina and her group for their warm hospitality and for taking such a good care of me.