Periodicities of polar mesospheric clouds inferred from a meteorological analysis and forecast system. Issue 8 (25th April 2017)

• Record Type: Journal Article
• Authors: Stevens, M. H.; Lieberman, R. S.; Siskind, D. E.; McCormack, J. P.; Hervig, M. E.; Englert, C. R.
• Is Part Of: Journal of geophysical research. Volume 122:Issue 8(2017)
• Page Start: 4508
• Page End: 4527
• Publication Date: 2017-04-25
• Subjects: mesosphere -- tides -- planetary waves -- PMC -- temperature; Atmospheric physics -- Periodicals; Geophysics -- Periodicals; 551.5
• DOI: 10.1002/2016JD025349
• Languages: English
• ISSNs: 2169-897X

Abstract

Abstract: There is currently an ambiguity in what controls polar mesospheric cloud (PMC) periodicities near 83 km altitude. This is primarily because satellite and ground‐based data sets cannot resolve global mesospheric temperature variability over the diurnal cycle. To address this limitation, we employ a global meteorological analysis and forecast system that assimilates mesospheric satellite data with two significant advances. The first is that we use output at a more rapid one hourly cadence, allowing for a quantitative description of diurnal (24 h), semidiurnal (12 h), and terdiurnal oscillations. The second is that the output drives a simple PMC parameterization which depends only on the local temperature, pressure, and water vapor concentrations. Our study focuses on results from July 2009 in the Northern Hemisphere and January 2008 in the Southern Hemisphere. We find that the 24 h migrating temperature tide as well as the 12 h and 24 h nonmigrating tides dominate northern PMC oscillations whereas the 12 h and 24 h nonmigrating tides dominate southern oscillations. Monthly averaged amplitudes for each of these components are generally 2–6 K with the larger amplitudes at lower PMC latitudes (50°). The 2 day and 5 day planetary waves also contribute in both hemispheres, with monthly averaged amplitudes from 1 to 3 K although these amplitudes can be as high as 4–6 K on some days. Over length scales of ~1000 km and timescales of ~1 week, we find that local temperature oscillations adequately describe midlatitude PMC observations. Key Points: Solar temperature tides and the 2 day and 5 day planetary waves are quantified throughout the northern and southern PMC regions The impact of these periodicities on PMC frequency and ice water content are determined PMC results are compared directly to two independent satellite data sets