Modeling Responses of Polar Mesospheric Clouds to Gravity Wave and Instability Dynamics and Induced Large‐Scale Motions

2021 ◽  
Author(s):  
Wenjun Dong ◽  
David C. Fritts ◽  
Gary E. Thomas ◽  
Thomas S. Lund
Keyword(s):  
Gravity Wave ◽  
Large Scale ◽  
Polar Mesospheric Clouds ◽  
Mesospheric Clouds

scholarly journals Universal power law of the gravity wave manifestation in the AIM CIPS polar mesospheric cloud images

2018 ◽  
Vol 18 (2) ◽  
pp. 883-899 ◽  
Author(s):  
Pingping Rong ◽  
Jia Yue ◽  
James M. Russell III ◽  
David E. Siskind ◽  
Cora E. Randall
Keyword(s):  
Normal Distribution ◽  
Gravity Wave ◽  
Power Spectra ◽  
Polar Mesospheric Clouds ◽  
Universal Power Law ◽  
Wave Morphology ◽  
Mesospheric Clouds ◽  
Morlet Wavelet Transform ◽  
Universal Law ◽  
Impact Sample

Abstract. We aim to extract a universal law that governs the gravity wave manifestation in polar mesospheric clouds (PMCs). Gravity wave morphology and the clarity level of display vary throughout the wave population manifested by the PMC albedo data. Higher clarity refers to more distinct exhibition of the features, which often correspond to larger variances and a better-organized nature. A gravity wave tracking algorithm based on the continuous Morlet wavelet transform is applied to the PMC albedo data at 83 km altitude taken by the Aeronomy of Ice in the Mesosphere (AIM) Cloud Imaging and Particle Size (CIPS) instrument to obtain a large ensemble of the gravity wave detections. The horizontal wavelengths in the range of  ∼ 20–60 km are the focus of the study. It shows that the albedo (wave) power statistically increases as the background gets brighter. We resample the wave detections to conform to a normal distribution to examine the wave morphology and display clarity beyond the cloud brightness impact. Sample cases are selected at the two tails and the peak of the normal distribution to represent the full set of wave detections. For these cases the albedo power spectra follow exponential decay toward smaller scales. The high-albedo-power category has the most rapid decay (i.e., exponent  =  −3.2) and corresponds to the most distinct wave display. The wave display becomes increasingly blurrier for the medium- and low-power categories, which hold the monotonically decreasing spectral exponents of −2.9 and −2.5, respectively. The majority of waves are straight waves whose clarity levels can collapse between the different brightness levels, but in the brighter background the wave signatures seem to exhibit mildly turbulent-like behavior.

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

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

scholarly journals The advective Brewer-Dobson circulation in the ERA5 reanalysis: variability and trends

2020 ◽  
Author(s):  
Mohamadou Diallo ◽  
Manfred Ern ◽  
Felix Ploeger
Keyword(s):  
Gravity Wave ◽  
Large Scale ◽  
Climate Model ◽  
Southern Oscillation ◽  
Natural Variability ◽  
Radiation Budget ◽  
Residual Circulation ◽  
Quasi Biennial Oscillation ◽  
Acceleration Rate ◽  
Good Agreement

Abstract. The stratospheric Brewer-Dobson circulation (BDC) is an important element of climate as it determines the transport and distributions of key radiatively active atmospheric trace gases, which affect the Earth’s radiation budget and surface climate. Here, we evaluate the inter-annual variability and trends of the BDC in the ERA5 reanalysis and inter-compare with the ERA-Interim reanalysis for the 1979–2018 period. We also assess the modulation of the circulation by the Quasi-Biennial Oscillation (QBO) and the El Niño-Southern Oscillation (ENSO), and the forcings of the circulation by the planetary and gravity wave drag. A comparison of ERA5 and ERA-Interim reanalyses shows a very good agreement in the morphology of the BDC and in its structural modulations by the natural variability related to QBO and ENSO. Despite the good agreement in the spatial structure, there are substantial differences in the strength of the BDC and of the natural variability impacts on the BDC between the two reanalyses, particularly in the upper troposphere and lower stratosphere (UTLS), and in the upper stratosphere. Throughout most regions of the stratosphere, the variability and trends of the advective BDC are stronger in the ERA5 reanalysis due to stronger planetary and gravity wave forcings, except in the UTLS below 20 km where the tropical upwelling is about 40 % weaker due to a weaker gravity wave forcings at the equatorial flank of the subtropical jet. In the extra-tropics, the large-scale downwelling is stronger in ERA5 than in ERA-Interim linked to significant differences in planetary and gravity wave forcings. Analysis of the BDC trend shows a global acceleration of the annual mean residual circulation with an acceleration rate of about 1.5 % per decade at 70 hPa due to the long-term intensification in gravity and planetary wave breaking, consistent with observed and future climate model predicted BDC changes.

scholarly journals Bright polar mesospheric clouds formed by main engine exhaust from the space shuttle's final launch

2012 ◽  
Vol 117 (D19) ◽  
pp. n/a-n/a ◽  
Author(s):  
Michael H. Stevens ◽  
Stefan Lossow ◽  
Jens Fiedler ◽  
Gerd Baumgarten ◽  
Franz-Josef Lübken ◽  
...  
Keyword(s):  
Engine Exhaust ◽  
Polar Mesospheric Clouds ◽  
Mesospheric Clouds ◽  
Main Engine
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