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Kivi, R.
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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 AccessPolar startospheric cloud observation at sodankyla (SF)(1995-09-18)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;Masci, F.; ING, Italy ;Rizi, V.; Dipartimento Di Fisica, Università di L'Aquila, Italy ;Visconti, G.; Dipartimento Di Fisica, Università di L'Aquila, Italy ;Weedekind, C.; Freie Universita Berlin, Germany ;Immler, F.; Freie Universita Berlin, Germany ;Mielke, B.; Freie Universita Berlin, Germany ;Rairoux, P.; Freie Universita Berlin, Germany ;Stein, B.; Freie Universita Berlin, Germany ;Woste, L.; Freie Universita Berlin, Germany ;Del Guasta, M.; IROE-CNR, Firenze, Italy ;Morandi, M.; IROE-CNR, Firenze(Italy) ;Stefanutti, L.; IROE-CNR, Firenze(Italy) ;Douard, M.; Universitè Lyon, France ;Wolf, J. P.; Universitè Lyon, France ;Kyro, E.; FMI,Sodankyla, Finland ;Kivi, R.; FMI,Sodankyla, Finland; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;Pyle, J. A. ;Harris, N. R. P.Amanatidis, G. T.We present some preliminary results of MOANA (Measurements and modelling of Ozone and Aerosols in the Northern Atmosphere) multi-wavelength lidar system, which was operating at Sodankyla (SF) during SESAME. We observed various polar stratospheric cloud (PSC) episodes; in this work we report the measurements of January 12 (JI2) and January 19 (J19), 1995. The J12 PSC has a layered structure and two of the three particle layers show a depolarised backscattering signal. On the other hand the J19 PSC detected between 19 and 24km is likely composed of spherical (liquid) particles because no depolarization shows up. In the last case an analysis of the lidar backscattering at the different wavelengths allows to estimate the optical size distribution of the particles.134 125 - PublicationOpen AccessResults of a trajectory box model simulating the size distribution evolution of stratospheric particles (H2SO4/H2O and H2SO4/HNO3/H2O solutions). A case study during SESAME(1995-09-18)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;Rizi, V.; Dipartimeto di Fisica, Università di L'Aquila, Italy ;Redaelli, G.; Dipartimeto di Fisica, Università di L'Aquila, Italy ;Visconti, G.; Dipartimeto di Fisica, Università di L'Aquila, Italy ;Masci, F.; ING, Italy ;Ivanova, I.; Bulgarian Academy of Science, Bulgaria ;Weedekind, C.; Freie Universitat Berlin, Germany ;Immler, F.; Freie Universitat Berlin, Germany ;Mielke, B.; Freie Universitat Berlin, Germany ;Rairoux, P.; Freie Universitat Berlin, Germany ;Stein, B.; Freie Universitat Berlin, Germany ;Woste, L.; Freie Universitat Berlin, Germany ;Matthey, R.; Observatorie Cantonal Neuchatel, Swizerland ;Mitev, V.; Observatorie Cantonal Neuchatel, Swizerland ;Douard, M.; Universitè, Lyon ;Wolf, J. P.; Universitè, Lyon ;Kyro, E.; FMI, Sodankyla, Finland ;Kivi, R.; FMI, Sodankyla, Finland; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;Pyle, A. ;Harris, N. R. P.Amanatidis, G. T.A revised interpretation of ER-2 polar stratospheric cloud (PSC) observations during AASE I (1989) and MOE (1987) Tabazadeh et al., 1995) suggests a picture of the PSC formations which evidences the importance of the air mass thermal histories. A series of ER-2 measurements are consistent with the thennodynamical properties of the liquid H2SO4/HNO3/H20 solution particles, but the data collected in other flights are in agreement with the possible formation of amorphous solid solutions of HNO3 and H2O through a peculiar coolingiheating cycle below the solid sulfuric acid tetrahydrate (SAT) melting temperatures and above the water ice saturation temperatures (frost point). During this cycle the liquid H2SO4 stratospheric aerosols may undergo a phase transition to SAT particles, required for the growing of solid nitric acid hydrates. On the other hand Koop et al., (1995) report laboratory experiments which show that H2SO4/HNO3/H20 liquid particles never freeze under stratospheric conditions for temperatures higher than the frost point. despite the change in composition due to the HNO3 uptake when cooling. In addition, when solid particles are heated, they start to become liquid at the SAT melting point. Then the analysis of any PSC data should start from air mass trajectory studies, and some thermodynamical criteria could be used to infer the physical state (liquid or solid) of the sampled particles. We use a trajectory box model to study the microphysical properties of stratospheric clouds observed during SESAME by the MOANA (Measurements and modelling of Ozone and Aerosols in the Northern Atmosphere) lidar at Sodankyla (SF). Our models treats the gas to particle conversion of H2SO4, HNO3, H2O and the microphysics of Aitken particles (ATK), H2SO4/H20 (WS) and H2SO4/HNO3/H20 (WSN) solution droplets; H2SO4 -nH2O (SA) and HNO3 -nH20 (NA) solid hydrates particles are also taken into account. To analyze the MOANA observations, within a prescribed air mass thermal history, we adopt a simple criteria which states that the particles should be liquid just after having performed temperatures above the SAT melting point. while they are solid if the water ice saturation temperatures are reached. The model simulations along the air mass trajectories reaching the lidar site during the observations are in agreement with the aerosol size distribution optically retrieved by the MOANA multiwavelength lidar (Masci et al., .1995).192 118