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Long-term variations of noctilucent clouds at ALOMAR
- Source :
- Journal of Atmospheric and Solar-Terrestrial Physics. 162:79-89
- Publication Year :
- 2017
- Publisher :
- Elsevier BV, 2017.
-
Abstract
- Noctilucent clouds (NLC) are measured by the Rayleigh/Mie/Raman-lidar at the ALOMAR research facility in Northern Norway (69°N, 16°E) since 1994. The data set contains about 2860 h of NLC detections and is investigated for the first time regarding trends. NLC properties depend on cloud brightness which is taken into account by the use of several cloud classes, related to brightness ranges. For NLC brighter than the long-term detection limit and strong NLC, respectively, the trend terms show increasing occurrence frequency (+9%/dec and+5%/dec) and brightness (+1.7×10−10 m−1 sr−1/dec and +1.5×−10 m−1 sr−1/dec) from 1998 to 2015. In the same period the altitude of faint and long-term limit clouds decreases (−66 m/dec and −108 m/dec). Over the entire time period of 22 years strong clouds show an increasing altitude by +76 m/dec. NLC properties are affected differently by solar and atmospheric parameters. In general, Lyman-α and stratospheric ozone impact all three NLC parameters, temperature at 83 km impacts mainly the NLC altitude. Time series of RMR lidar and SBUV satellite instruments match best for NLC occurrence frequency and brightness when restricting SBUV to the morning data at longitudes around ALOMAR (64–74°N, 8–24°E/0–9 LT). This suggests longitudinal dependent trends, which is confirmed by trend investigations of longitudinal subsets of the SBUV data set.
- Subjects :
- Atmospheric Science
Brightness
010504 meteorology & atmospheric sciences
Meteorology
Atmospheric sciences
01 natural sciences
Term (time)
Northern norway
Geophysics
Altitude
Lidar
Space and Planetary Science
0103 physical sciences
Ozone layer
Environmental science
Satellite
010303 astronomy & astrophysics
0105 earth and related environmental sciences
Subjects
Details
- ISSN :
- 13646826
- Volume :
- 162
- Database :
- OpenAIRE
- Journal :
- Journal of Atmospheric and Solar-Terrestrial Physics
- Accession number :
- edsair.doi...........ec16a1b315ef28b0b5368316b8624d6c