scholarly journals Local and Remote Planetary Wave Effects on Polar Mesospheric Clouds in the Northern Hemisphere in 2014

2018 ◽  
Vol 123 (10) ◽  
pp. 5149-5162 ◽  
Author(s):  
J. A. France ◽  
C. E. Randall ◽  
R. S. Lieberman ◽  
V. L. Harvey ◽  
S. D. Eckermann ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Planetary Wave ◽  
Polar Mesospheric Clouds ◽  
Wave Effects ◽  
Mesospheric Clouds

Properties of polar mesospheric clouds measured by Odin/OSIRIS in the northern hemisphere in 2002–2005

2007 ◽  
Vol 85 (11) ◽  
pp. 1143-1158 ◽  
Author(s):  
S V Petelina ◽  
E J Llewellyn ◽  
D A Degenstein
Keyword(s):  
Interannual Variability ◽  
Northern Hemisphere ◽  
Occurrence Frequency ◽  
High Latitudes ◽  
Polar Mesospheric Clouds ◽  
Infrared Imager ◽  
The Mean ◽  
Mesospheric Clouds

Interseasonal variations in the properties of Polar Mesospheric Clouds (PMC) measured by the Optical Spectrograph and InfraRed Imager System (OSIRIS) on the Odin satellite during the northern hemisphere (NH) summers of 2002–2005 are described in this work. The lowest PMC latitudes were about 50°N for every season with the number of detections smallest in 2002 and largest in 2004. In 2004 and 2005, the detection of PMCs at lower latitudes was asymmetric with the larger number of clouds observed during the first half and fewer at during the second half of the season. PMC occurrence frequency in 2002 was 25–30% lower than in 2003–2005, and the season duration was shortest in 2002 and longest in 2004. For all NH seasons except 2002, PMC occurrence frequency was systematically 20–50% higher than the Solar Mesosphere Explorer climatology. Similar to PMC occurrence frequency, cloud brightness was lowest in 2002 and highest in 2004 at all latitudes. The daily mean brightness maximum at 50°–60°N was less than 8% of that at highest latitudes. This contrasts with the maximum PMC occurrence frequency that reached nearly 30% at these latitudes in 2004 and 2005. PMC brightness showed no apparent seasonal asymmetry at lower latitudes in 2004 and 2005 that was seen in the occurrence frequency. Significant, by about a factor of 2, oscillations observed in the daily mean cloud brightness at high latitudes were also not seen in the corresponding occurrence frequency. These results suggest that the occurrence frequency alone does not provide detailed information on the cloud population and ice mass in the mesosphere. There is no significant interannual variability in the seasonal mean OSIRIS PMC altitude. Its value was very close to 8350 km for all seasons except 2004 when it was 83.42 km. The mean PMC altitudes for each season increased by 0.3–0.6 when the minimum altitude in the database was increased from 80 to 82 km. PACS Nos.: 92.05.Fg, 92.60.hc, 92.60.Jq, 92.60.Mt, 92.60.Nv, 92.60.Vb

scholarly journals Long term variations in the frequency of polar mesospheric clouds in the Northern Hemisphere from SBUV

2009 ◽  
Vol 36 (2) ◽  
pp. n/a-n/a ◽  
Author(s):  
E. P. Shettle ◽  
M. T. DeLand ◽  
G. E. Thomas ◽  
J. J. Olivero
Keyword(s):  
Northern Hemisphere ◽  
Polar Mesospheric Clouds ◽  
Mesospheric Clouds ◽  
Long Term Variations

Middle ultraviolet imager observations of the distribution of polar mesospheric clouds

2001 ◽  
Vol 27 (10) ◽  
pp. 1703-1708 ◽  
Author(s):  
J.F. Carbary ◽  
D. Morrison ◽  
G.J. Romick ◽  
L.J. Paxton ◽  
C.-I. Meng
Keyword(s):  
Polar Mesospheric Clouds ◽  
Mesospheric Clouds

Comparison of Key Characteristics of Remarkable SSW Events in the Southern and Northern Hemisphere

2021 ◽  
Author(s):  
Michal Kozubek ◽  
Peter Krizan
Keyword(s):  
Northern Hemisphere ◽  
Planetary Wave ◽  
Polar Vortex ◽  
Wave Number ◽  
Strong Activity ◽  
Key Characteristics ◽  
Zonal Wave Number ◽  
Show Difference ◽  
Temperature Enhancement ◽  
Stationary Planetary Wave

<p>An exceptionally strong sudden stratospheric warming (SSW) in the Southern Hemisphere (SH) during September 2019 was observed. Because SSW in the SH is very rare, comparison with the only recorded major SH SSW is done. According to World Meteorological Organization (WMO) definition, the SSW in 2019 has to be classified as minor. The cause of SSW in 2002 was very strong activity of stationary planetary wave with zonal wave-number (ZW) 2, which reached its maximum when the polar vortex split into two circulations with polar temperature enhancement by 30 K/week and it penetrated deeply to the lower stratosphere and upper troposphere. On the other hand, the minor SSW in 2019 involved an exceptionally strong wave-1 planetary wave and a large polar temperature enhancement by 50.8 K/week, but it affected mainly the middle and upper stratosphere. The strongest SSW in the Northern Hemisphere was observed in 2009. This study provides comparison of two strongest SSW in the SH and the strongest SSW in the NH to show difference between two hemispheres and possible impact to the lower or higher layers.</p>

scholarly journals A new Description of Probability Density Distributions of Polar Mesospheric Clouds (PMC)

2018 ◽  
Author(s):  
Uwe Berger ◽  
Gerd Baumgarten ◽  
Jens Fiedler ◽  
Franz-Josef Lübken
Keyword(s):  
Probability Density ◽  
Mass Density ◽  
Particle Radius ◽  
Number Density ◽  
Data Set ◽  
Statistical Probability ◽  
Polar Mesospheric Clouds ◽  
Density Distributions ◽  
Mesospheric Clouds ◽  
Probability Density Distributions

Abstract. In this paper we present a new description about statistical probability density distributions (pdfs) of Polar Mesospheric Clouds (PMC) and noctilucent clouds (NLC). The analysis is based on observations of maximum backscatter, ice mass density, ice particle radius, and number density of ice particles measured by the ALOMAR RMR-lidar for all NLC seasons from 2002 to 2016. From this data set we derive a new class of pdfs that describe the statistics of PMC/NLC events which is different from previously statistical methods using the approach of an exponential distribution commonly named g-distribution. The new analysis describes successfully the probability statistic of ALOMAR lidar data. It turns out that the former g-function description is a special case of our new approach. In general the new statistical function can be applied to many kinds of different PMC parameters, e.g. maximum backscatter, integrated backscatter, ice mass density, ice water content, ice particle radius, ice particle number density or albedo measured by satellites. As a main advantage the new method allows to connect different observational PMC distributions of lidar, and satellite data, and also to compare with distributions from ice model studies. In particular, the statistical distributions of different ice parameters can be compared with each other on the basis of a common assessment that facilitate, for example, trend analysis of PMC/NLC.

Climatology of Polar Mesospheric Clouds

1986 ◽  
Vol 43 (12) ◽  
pp. 1263-1274 ◽  
Author(s):  
John J. Olivero ◽  
Gary E. Thomas
Keyword(s):  
Polar Mesospheric Clouds ◽  
Mesospheric Clouds
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