Oceanologia

Oceanologia

Volume 63, Issue 2, April–June 2021, Pages 238-246
Oceanologia

Original Research Article
Lidar observation of aerosol transformation in the atmospheric boundary layer above the Baltic Sea

https://doi.org/10.1016/j.oceano.2021.01.002Get rights and content
Under a Creative Commons license
open access

Highlights

  • Profiles of the aerosol effective radius were measured over the Baltic Sea.

  • Data from lidar measurements and theoretical calculation was used.

  • The sea spray generation functions should include the dependence of ASPD on wind speed.

Abstract

Investigation results of a coarse and accumulation mode of aerosol properties above the Baltic Sea are reported. A most important role in the direct aerosol effect on climate have aerosols from the group of coarse and accumulation mode particles. Overseas in the atmosphere, there is a lot of aerosols from the fine fraction but their impact is not so important as coarse and accumulation mode particles. Sea spray emission from the sea surface takes place over a wide range of aerosol particle size distribution, it is also large in size range which are studying in this work (Lewis and Schwartz, 2004). The discussed range is most important in view of atmospheric optical properties, smaller particles do not have such an influence on scattering as particles from range 0.5–2 µm. The research was performed with a multiwavelength lidar. Due to the application of special software, the aerosol particle size distributions were retrieved from the lidar returns. That provided an opportunity to determine the profiles of the aerosol effective radius. We showed that the aerosol properties depend mainly on the direction of the air mass advection and the wind speed. The impact of the Baltic Sea on the aerosol size distribution is huge in the case of the advection from the open sea. Moreover, the aerosol effective radiuses in the whole boundary layer are much larger in the case of strong than for light wind. Our results suggest that the aerosol flux and the aerosol particle size distribution should be related to the wind speed in the emission function.

Keywords

Aerosol
Lidars measurements
Atmospheric boundary layer

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