The quasi 16-day wave in mesospheric water vapor during boreal winter 2011/2012

Abstract

Abstract. This study investigates the characteristics of the quasi 16-day wave in the mesosphere during boreal winter 2011/2012 using observations of water vapor from groundbased microwave radiometers and satellite data. The groundbased microwave radiometers are located in Seoul (South Korea, 37 • N), Bern (Switzerland, 47 • N) and Sodankylä (Finland, 67 • N). The quasi 16-day wave is observed in the mesosphere at all three locations, while the dominant period increases with latitude from 15 days at Seoul to 20 days at Sodankylä. The observed evolution of the quasi 16-day wave confirms that the wave activity is strongly decreased during a sudden stratospheric warming that occurred in midJanuary 2012. Using satellite data from the Microwave Limb Sounder on the Aura satellite, we examine the zonal characteristics of the quasi 16-day wave and conclude that the observed waves above the midlatitudinal stations Seoul and Bern are eastward-propagating s = −1 planetary waves with periods of 15 to 16 days, while the observed oscillation above the polar station Sodankylä is a standing wave with a period of approximately 20 days. The strongest relative wave amplitudes in water vapor during the investigated time period are approximately 15 %. The wave activity varies strongly along a latitude circle. The activity of the quasi 16-day wave in mesospheric water vapor during boreal winter 2011/2012 is strongest over northern Europe, the North Atlantic Ocean and northwestern Canada. The region of highest wave activity seems to be related to the position of the polar vortex. We conclude that the classic approach to characterize planetary waves zonally averaged along a latitude circle is not sufficient to explain the local observations because of the strong longitudinal dependence of the wave activity.

Signatures of the 2-day wave and sudden stratospheric warmings in Arctic water vapour observed by ground-based microwave radiometry

“…We successfully applied this method to other middle atmospheric trace gas studies (e.g. Hocke et al, 2013;Scheiben et al, 2014). The wavelet-like analysis has the advantage of capturing variations with non-persistent phase.…”

“…Spectral decomposition of MIAWARA-C's time series showed dominant variations with periods of approximately 16, 10, 5 and 2 days. A detailed analysis of the evolution and regional differences of the quasi-16-day wave for winter 2011/12 has already been presented in Scheiben et al (2014) using ground-based microwave data of trace gases including the data obtained with MIAWARA-C. In this study we concentrate on the investigation of the Q2DW.…”

“…Investigation of the quasi-16-day wave in mesospheric water vapour during the boreal winter 2011/12 based on data from MIAWARA-C has already been presented in Scheiben et al (2014). This paper focuses on the effect of SSWs and the Q2DW.…”

Quasi 18 h wave activity in ground-based observed mesospheric H<sub>2</sub>O over Bern, Switzerland

“…It is the only instrument capable of steadily observing wind in the otherwise sparsely probed atmospheric layer between 35 and 70 km altitude. Other techniques like rocket (Schmidlin, 1986) or lidar-based measurements (Lübken et al, 2016;Baumgarten et al, 2015) can provide wind data in this region with a higher vertical and temporal resolution than WIRA but suffer from high operational costs (rockets, lidar) or cloudy conditions (lidar). Meteorological rocket soundings are thus only suitable for short campaigns, not for continuous observations.…”

Variability of mesospheric water vapor above Bern in relation to the 27-day solar rotation cycle

“…Many studies contributed to the understanding of waves in the middle atmosphere with periods of 2 days (Salby, 1981;Yue et al, 2012), 5 days (Wu et al, 1994;Riggin et al, 2006), and 16 days (McDonald et al, 2011;Scheiben et al, 2014). A few papers considered variations from 20 days up to three months (Wu and Jiang, 2005;Mayr et al, 2009;Studer et al, 2012).…”