Lidar observed polar stratospheric clouds over Svalbard in mid-December 1994 (scientific paper)
Polar stratospheric clouds (PSCs) were observed with lidar at Ny-Ålesund, Svalbard in the winter of 1994/1995. Compared with the temperature record over several years, the stratospheric temperature over Ny-Ålesund was very low in December and January in this winter. In the period when the PSCs were...
Summary: | Polar stratospheric clouds (PSCs) were observed with lidar at Ny-Ålesund, Svalbard in the winter of 1994/1995. Compared with the temperature record over several years, the stratospheric temperature over Ny-Ålesund was very low in December and January in this winter. In the period when the PSCs were first observed in mid-December, a slight increase of stratospheric aerosols at the top side of the background aerosol layer was found. This increase can be understood as the first stage of PSC formation in the winter. The lidar-observed PSCs in this period are characterized by high variability in space and/or time. As a typical example of these features, an event on December 12,13 and 14 is presented. In this case two layers of scattering ratio and depolarization were observed within about one km of the vertical separation. The life time of the layers was only a few hours. The characteristics of the PSCs in this period cannot be simply explained by the NAT formation theory which has been widely accepted. |
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