Occurrence of polar stratospheric clouds at Kiruna
Abstract. Polar stratospheric clouds (PSCs) are often observed in the Kiruna region in northern Sweden, east of the Scandinavian mountain range, during wintertime. PSC occurrence can be detected by ground-based optical instruments. Most of these require clear tropospheric weather. By applying the ze...
| Main Authors: | , , , , , , |
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.371.8679 http://hal.archives-ouvertes.fr/docs/00/31/67/11/PDF/angeo-17-1457-1999.pdf |
| Summary: | Abstract. Polar stratospheric clouds (PSCs) are often observed in the Kiruna region in northern Sweden, east of the Scandinavian mountain range, during wintertime. PSC occurrence can be detected by ground-based optical instruments. Most of these require clear tropospheric weather. By applying the zenith-sky colour index technique, which works under most weather conditions, the data availability can be extended. The observations suggest that PSC events, especially of type II (water PSCs) may indeed more common than predicted by synoptic models, which is expected because of the frequent presence of mountain-induced leewaves. However, it will be of importance to increase the density of independent observations. Key words. Atmospheric composition and structure (aerosols and particles, cloud physics and chemistry) á Meteorology and atmospheric dynamics (mesoscale meteorology) (ECMWF). That method does not account for PSC formation by local cooling in mountain-induced waves, which can be observed in certain areas close to mountain ridges, such as the Kiruna region in northern Sweden. It has been proposed by Carslaw et al. (1998) that these wave-induced PSCs may be a major cause of the discrepancies between observed and modelled ozone loss. However, their importance is still the object of much controversy. An experimental climatology of actual PSC observations is therefore desirable, which means that the density of such observations must be increased. A number of optical remote-sensing instruments suitable for that purpose are at present in operation around the Scandinavian mountain range, both active (lidars) and passive (spectrometers and cameras). The ®nal aim may be PSC mapping using satellite data (Garcia et al., 1995; MeerkoÈ tter, 1995). This procedure will require calibration against ground-based instruments. |
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