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Finnish Meteorological Institute
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- PublicationRestrictedTrajectory studies of Polar Statospheric Cloud Lidar Observations at Sodankyla (Finland) during SESAME: comparison with box model results of particle evolution(1999)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;Rizi, V.; Dipartimento di Fisica, Università di L'Aquila ;Redaelli, G.; Dipartimento di Fisica, Università di L'Aquila ;Visconti, G.; Dipartimento di Fisica, Università di L'Aquila ;Masci, F.; ING ;Wedekind, C.; Freie Universitat Berlin ;Stein, B.; Freie Universitat Berlin ;Immler, F.; Freie Universitat Berlin ;Mielke, B.; Freie Universitat Berlin ;Rairoux, P.; Freie Universitat Berlin ;Woste, L.; Freie Universitat Berlin ;Del Guasta, M.; IROE CNR ;Morandi, M.; IROE CNR ;Castagnoli, F.; IROE CNR ;Balestri, S.; IROE CNR ;Stefanutti, L.; IROE CNR ;Matthey, R.; Observatoire Cantonal Neuchatel ;Mitev, V.; Observatoire Cantonal Neuchatel ;Douard, M.; Universitè Lion ;Wolf, J. P.; Universitè Lion ;Kiro, E.; Finnish Meteorological Institute ;Rummukainen, M.; Finnish Meteorological Institute ;Kivi, R.; Finnish Meteorological Institute; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; Polar statospheric clouds (PSC) were observed with the milti-wavelengh lidar of the MOANA project during SESAME. The physical state, liquid or solid, of the cloud particles can be inferred from the lidar data. Using isentropic back-trajectories to obtain the thermal history of the sampled air masses, it is possible to reconcile most of the observations with current ideas on PSC formation and evolution. When the cloud particles were identified as liquid, changes in the size distributionof the droplets along the trajectory ewre calculated using micro-physical box model. Backscatter ratios ......165 26 - PublicationOpen AccessObservation of Liquid Particles at -65° in a Polar Cirrus(1995-11-06)
; ; ; ; ; ; ; ; ; ; ; ; ;Del Guasta, M.; IROE-CNR, Firenze, Italy ;Morandi, M.; IROE-CNR, Firenze, Italy ;Stefanutti, L.; IROE-CNR, Firenze, Italy ;Balestri, S.; IROE-CNR, Firenze, Italy ;Castagnoli, F.; IROE-CNR, Firenze, Italy ;Kyro, E.; FMI, Sodankyla, Finland ;Rummukainen, M.; FMI, Sodankyla, Finland ;Rizi, V.; Dipartimento di Fisica, Università di L'Aquila, Italy ;Masci, F.; ING, Italy ;Stein, B.; Freie Universita Berlin, Germany ;Mielke, B.; Freie Universita Berlin, Germany ;Matthey, R.; Observatoire Cantonal Neuchatel, Switzerland; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;Colacino, M. ;Giovanelli, G.Stefanutti, L.It is widely accepted that pure water cannot exist as a liquid below about -40°. Theoretical and laboratory studies confirm this behavior for pure water. Liquid droplets have been seldom observed in cirrus clouds down to about -50°C. The LIDAR technique can help to find out unusual supercooled clouds, when the depolarization technique is implemented: the presence of non-depolarizing layers in a cloud is indicative of a very special scattering media: scattering particles must have a symmetry axis oriented along the laser beam. This is possible either with spherical droplets or ice plates horizontally oriented. In this work, a -65°C cold, non-depolarizing cloud observed in Finland is studied, concluding that supercooled droplets are responsible for the absence of depolarization in most of the cloud. This is the coldest supercooled cirrus ever observed.144 191