Comparison of retrieved noctilucent cloud particle properties from Odin tomography scans and model simulations
-
Published:2016-12-07
Issue:23
Volume:16
Page:15135-15146
-
ISSN:1680-7324
-
Container-title:Atmospheric Chemistry and Physics
-
language:en
-
Short-container-title:Atmos. Chem. Phys.
Author:
Megner Linda, Christensen Ole M.ORCID, Karlsson Bodil, Benze Susanne, Fomichev Victor I.
Abstract
Abstract. Mesospheric ice particles, known as noctilucent clouds or polar mesospheric clouds, have long been observed by rocket instruments, satellites and ground-based remote sensing, while models have been used to simulate ice particle growth and cloud properties. However, the fact that different measurement techniques are sensitive to different parts of the ice particle distribution makes it difficult to compare retrieved parameters such as ice particle radius or ice concentration from different experiments. In this work we investigate the accuracy of satellite retrieval based on scattered light and how this affects derived cloud properties. We apply the retrieval algorithm on spectral signals calculated from modelled cloud distributions and compare the results to the properties of the original distributions. We find that ice mass density is accurately retrieved whereas mean radius is often overestimated and high ice concentrations are generally underestimated. The reason is partly that measurements based on scattered light are insensitive to the smaller particles and partly that the retrieval algorithm assumes a Gaussian size distribution. Once we know the limits of the satellite retrieval we proceed to compare the properties retrieved from the modelled cloud distributions to those observed by the Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) instrument on the Odin satellite. We find that a model with a stationary atmosphere, as given by average atmospheric conditions, does not yield cloud properties that are in agreement with the observations, whereas a model with realistic temperature and vertical wind variations does. This indicates that average atmospheric conditions are insufficient to understand the process of noctilucent cloud growth and that a realistic atmospheric variability is crucial for cloud formation and growth. Further, the agreement between results from the model, when set up with a realistically variable atmosphere, and the observations suggests that our understanding of the growth process itself is reasonable.
Funder
Canadian Space Agency
Publisher
Copernicus GmbH
Subject
Atmospheric Science
Reference47 articles.
1. Asmus, H., Robertson, S., Dickson, S., Friedrich, M., and Megner, L.: Charge balance for the mesosphere with meteoric dust particles, J. Atmos. Sol.-Terr. Phy., 127, 137–149, https://doi.org/10.1016/j.jastp.2014.07.010, 2015. 2. Bailey, S. M., Thomas, G. E., Hervig, M. E., and Lumpe, J. D.: Comparing nadir and limb observations of polar mesospheric clouds: The effect of the assumed particle size distribution, J. Atmos. Sol.-Terr. Phy., 127, 51–65, https://doi.org/10.1016/j.jastp.2015.02.007, 2015. 3. Bardeen, C. G., Toon, O. B., Jensen, E. J., Marsh, D. R., and Harvey, V. L.: Numerical simulations of the three-dimensional distribution of meteoric dust in the mesosphere and upper stratosphere, J. Geophys. Res., 113, D17202, https://doi.org/10.1029/2007JD009515, 2008. 4. Barth, C. A., Rusch, D. W., Thomas, R. J., Mount, G. H., Rottman, G. J., Thomas, G. E., Sanders, R. W., and Lawrence, G. M.: Solar Mesosphere Explorer: Scientific objectives and results, Geophys. Res. Lett., 10, 237–240, https://doi.org/10.1029/GL010i004p00237, 1983. 5. Baumgarten, G., Fiedler, J., Lübken, F.-J., and von Cossart, G.: Particle properties and water content of noctilucent clouds and their interannual variation, J. Geophys. Res.-Atmos., 113, D06203, https://doi.org/10.1029/2007JD008884, 2008.
Cited by
7 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
|
|