Stratospheric aerosol size distributions from multispectral lidar measurements at Sodankylä during EASOE

Abstract

Multispectral lidar data measured at Sodankylä (67°N, 26°E), have been used to characterize stratospheric aerosols. Using depolarization measurements, particles have been classified into PSC and volcanic aerosols. While Pinatubo aerosol could be observed inside the polar vortex from the beginning of the campaign, only few PSC events have been observed. For Pinatubo aerosol lognormal size distribution parameters have been retrieved, indicating particle distributions with 0.1 µm to 0.3 µm median‐radius between 17 and 22 km and up to 0.7 µm below. Height resolved size distribution parameters and aerosol surface areas are given.

Statistical mechanics of fullerene coalescence growth

“…24 It expresses an accelerated growth of larger particles at the expense of smaller ones. This growth characteristics is wellknown, e.g., for atmospheric aerosols 27 and snow crystals 28 merging onto inelastic collision. When this picture is transferred to the case of cluster condensation the size statistics emerges from the second order reaction [16][17][18] inferred from purely classical inelastic two-body collisions between two cluster species ͑I − J͒ and J in the plasma to form the species I:…”

A new regularized inversion method for the retrieval of stratospheric aerosol size distributions applied to 16 years of SAGE II data (1984–2000): method, results and validation

“…As an example, Deshler (1994) observed strong variations between four successive measurements carried out over Kiruna within a delay of one month, due to the displacement of the polar vortex position and the local incursion of midlatitude air masses. Another illustration is given by the comparison between lidar measurements carried out by Stein et al (1994) at Sodankylä (67 • N, 26 • E) on 13 February 1992, and Deshler's measurements (Deshler, 1994) on the same date above Kiruna (68 • N, 21 • E). Despite the proximity of these observations, both data sets show discrepancies up to about 20% on the mode radius, and about a factor of 2 on the particle number density.…”

“…Deshler et al, 1992Deshler et al, , 1993Deshler, 1994;Sugita et al, 1999) and observations from ground based lidar stations (e.g. Del Guzzi et al, 1999;Stein et al, 1994) are very useful complementary approaches, giving direct access to accurate information about the aerosol characteristics. The disposal of adequate impactors and particle counters allows quite a reliable description and quantification of very thin aerosol particles and condensation nuclei.…”

Airborne Instrumentation for Aerosol Measurements

“…For such cases, if the particles are liquid and hence spherical, it is possible, by means of multispectral investigation and Mie theory calculations, to derive the particle size distribution. (28,29) For solid aspherical particles, general analytical solutions of the Maxwell equations can be obtained for simple cases (i.e. spheroids, Chebyshev particles, etc.)…”

“…Then, in the case of spherical particles, using multispectral LIDARs, it is possible to invert the LIDAR signatures to obtain the particle size distribution and index of refraction by means of Mie theory computations. (28,32,33) These techniques have already been accomplished by ground-based LIDARs, and a wide network of multispectral LIDAR systems is presently operating at very different latitudes and longitudes. For cloud particle size evaluation, with particles in the range between tens and hundreds of micrometers, an equivalent set of wavelengths in this range would be necessary.…”