Identification of polar stratospheric clouds from the ground by visible spectrometry

• Published in: Geophysical research letters Vol. 18; no. 4; pp. 779 - 782
• Main Authors: Sarkissian, A., Pommereau, J. P., Goutail, F.
• Format: Journal Article
• Language: English
• Published: Washington, DC Blackwell Publishing Ltd 01.04.1991; American Geophysical Union
• Subjects: 540110; AEROSOLS; Atmospheric composition. Chemical and photochemical reactions; CLOUDS; COLLOIDS; COLOR; DISPERSIONS; EARTH ATMOSPHERE; Earth, ocean, space; ENERGY TRANSFER; ENVIRONMENTAL SCIENCES; Exact sciences and technology; External geophysics; Geophysics; Grounds; HEAT TRANSFER; HYDRATES; HYDROGEN COMPOUNDS; INORGANIC ACIDS; LAYERS; LEVELS; MATHEMATICAL MODELS; NITRIC ACID; OPTICAL PROPERTIES; ORGANOLEPTIC PROPERTIES; OZONE LAYER; PHYSICAL PROPERTIES; Physics of the high neutral atmosphere; POLAR REGIONS; RADIANT HEAT TRANSFER; RADIATIONS; Sky; SOLAR RADIATION; SOLS; SPECTROSCOPY; Statistics; STELLAR RADIATION; STRATOSPHERE; TROPOSPHERE; Twilight; VAPOR CONDENSATION; WEATHER; Sweden; Polar stratospheric cloud; Europe; Ground based measurement; Stratosphere; Visible spectrometry; Models; Radiative transfer; Arctic Region; Upper atmosphere; Twilight sky
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/91GL00769

When sighted from the ground in clear weather, stratospheric clouds make large changes in the sky color during twilight. Spectrometric measurements performed from the ground during CHEOPS show that the color changes can be either large reddenings or blueings. A radiative transfer model demonstrates that the first are caused by thin hazes above 22 km while the second are related to thick clouds below, and that the color change during twilight is little sensitive to tropospheric clouds. Statistics of presence of PSC's above Kiruna during CHEOPS which shows that reddenings are correlated with temperature below NAT condensation at high altitude (30 hPa, 21.5 km) and blueings at low altitude (50 hPa, 18.5km), support this interpretation, as also the consistency with PSC measurements with in‐situ aerosol counters, balloon radiometer and from satellite observations. Spectrometric observations of the zenith sky at twilight is therefore thought to be a powerful method for identifying the presence and the altitude of PSCs above a station in all tropospheric weather conditions.