Polar mesosphere winter echoes during MaCWAVE

Kirkwood, S.; Belova, Evgenia; Blum, U.; Croskey, C. L.; Dalin, Peter; Fricke, K. H.; Goldberg, R. A.; Manninen, J.; Mitchell, John; Schmidlin, F. J.

doi:10.5194/angeo-24-1245-2006

Cited by 43 publications

(83 citation statements)

References 27 publications

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“…The median value of the HPHW is ∼ 6.8 m s −1 and the median value of the energy dissipation rate is ∼ 238.5 mW kg −1 . This value is larger than reported by Lübken et al (2007) and Kirkwood et al (2006a) during PMWE events. Also, in situ measurements in the winter mesosphere without PMWE (Lübken et al, 1993b;Lübken, 1997a) reveal considerably smaller values.…”

Section: Discussioncontrasting

confidence: 53%

“…Lübken et al, 2006Lübken et al, , 2007Rapp et al, 2011;Morris et al, 2011). However, measurements with lidar and radar (Kirkwood et al, 2002;Stebel et al, 2004;Belova et al, 2005;Kero et al, 2008;La Hoz and Havnes, 2008) have triggered the hypothesis that small charged aerosol particles (probably of meteoric origin) play a similar role as in the case of PMSE (e.g. Rapp and Lübken, 2004).…”

Section: Introductionmentioning

confidence: 99%

“…Previous work has clearly shown that a sufficiently high ionization level caused e.g. by sufficiently large, highly energetic proton (and electron) fluxes or enhanced X-ray fluxes are an essential prerequisite for the existence of PMWE (Kirkwood et al, 2002;Zeller et al, 2006;Kirkwood et al, 2006a).…”

Section: Introductionmentioning

confidence: 99%

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Statistical characteristics of PMWE observations by the EISCAT VHF radar

Strelnikova¹,

Rapp

2013

Ann. Geophys.

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In the present paper ~ 32.5 h of EISCAT VHF PMWE observations were analyzed with focus on spectral properties like spectral width, doppler shift and spectral shape. Examples from two days of observations with weak and strong polar mesosphere winter echo (PMWE) signals are presented and discussed in detail. These examples reveal a large variability from one case to the other. That is, some features like an observed change of vertical wind direction and spectral broadening can be very prominent in one case, but unnoticeable in the other case. However, for all observations a change of spectral shape inside the layer relative to the incoherent background is noticed

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Section: Discussioncontrasting

confidence: 53%

Section: Introductionmentioning

confidence: 99%

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Statistical characteristics of PMWE observations by the EISCAT VHF radar

Strelnikova¹,

Rapp

2013

Ann. Geophys.

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“…These models have been extensively tested in various different conditions (auroral electron precipitation, solar proton events, quiet conditions) with ionization sources according to satellite measurements and electron-density measurements by sounding rockets, by partial-reflection radar and by the EIS-CAT incoherent-scatter radar (e.g. Kirkwood and Eliasson, 1990;Kirkwood et al, 2002;Osepian et al, 2009a, b). These models use simplified ion-chemistry and prescribed traceconstituent models to allow computational efficiency in calculating electron density profiles, as well as their dependence on trace constituents, which can be readily compared with observations.…”

Section: Ion and No Production Rate Modelmentioning

confidence: 99%

Ionization and NO production in the polar mesosphere during high-speed solar wind streams: model validation and comparison with NO enhancements observed by Odin-SMR

et al. 2015

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Abstract. Precipitation of high-energy electrons (EEP) into the polar middle atmosphere is a potential source of significant production of odd nitrogen, which may play a role in stratospheric ozone destruction and in perturbing large-scale atmospheric circulation patterns. High-speed streams of solar wind (HSS) are a major source of energization and precipitation of electrons from the Earth's radiation belts, but it remains to be determined whether these electrons make a significant contribution to the odd-nitrogen budget in the middle atmosphere when compared to production by solar protons or by lower-energy (auroral) electrons at higher altitudes, with subsequent downward transport. Satellite observations of EEP are available, but their accuracy is not well established. Studies of the ionization of the atmosphere in response to EEP, in terms of cosmic-noise absorption (CNA), have indicated an unexplained seasonal variation in HSS-related effects and have suggested possible order-ofmagnitude underestimates of the EEP fluxes by the satellite observations in some circumstances. Here we use a model of ionization by EEP coupled with an ion chemistry model to show that published average EEP fluxes, during HSS events, from satellite measurements (Meredith et al., 2011), are fully consistent with the published average CNA response (Kavanagh et al., 2012). The seasonal variation of CNA response can be explained by ion chemistry with no need for any seasonal variation in EEP. Average EEP fluxes are used to estimate production rate profiles of nitric oxide between 60 and 100 km heights over Antarctica for a series of unusually well separated HSS events in austral winter 2010. These are compared to observations of changes in nitric oxide during the events, made by the sub-millimetre microwave radiometer on the Odin spacecraft. The observations show strong increases of nitric oxide amounts between 75 and 90 km heights, at all latitudes poleward of 60 • S, about 10 days after the arrival of the HSS. These are of the same order of magnitude but generally larger than would be expected from direct production by HSS-associated EEP, indicating that downward transport likely contributes in addition to direct production.

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“…Nielson et al (2006) analyze the character of small-scale gravity wave and instability structures near the mesopause in winter. Finally, Kirkwood et al (2006), Williams et al (2006b), and Croskey et al (2006) examine the microphysics underlying polar mesosphere winter echoes, correlated sporadic sodium and E layers, and plasma structures at small spatial scales. Figure 1 is an artist's conception designed to describe the summer 2002 program at ARR in Norway.…”

Section: Introductionmentioning

confidence: 99%

The MaCWAVE program to study gravity wave influences on the polar mesosphere

et al. 2006

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Abstract. MaCWAVE (Mountain and Convective WavesAscending VErtically) was a highly coordinated rocket, ground-based, and satellite program designed to address gravity wave forcing of the mesosphere and lower thermosphere (MLT). The MaCWAVE program was conducted at the Norwegian Andøya Rocket Range (ARR, 69.3 • N) in July 2002, and continued at the Swedish Rocket Range (Esrange, 67.9 • N) during January 2003. Correlative instrumentation included the ALOMAR MF and MST radars and RMR and Na lidars, Esrange MST and meteor radars and RMR lidar, radiosondes, and TIMED (Thermosphere Ionosphere Mesosphere Energetics and Dynamics) satellite measurements of thermal structures. The data have been used to define both the mean fields and the wave field structures and turbulence generation leading to forcing of the large-scale flow. In summer, launch sequences coupled with groundbased measurements at ARR addressed the forcing of the summer mesopause environment by anticipated convective and shear generated gravity waves. These motions were measured with two 12-h rocket sequences, each involving one Terrier-Orion payload accompanied by a mix of MET rockets, all at ARR in Norway. The MET rockets were used to define the temperature and wind structure of the stratosphere and mesosphere. The Terrier-Orions were designed to measure small-scale plasma fluctuations and turbulence that might be induced by wave breaking in the mesosphere. For the summer series, three European MIDAS (Middle Atmosphere Dynamics and Structure) rockets were also launched from ARR in coordination with the MaCWAVE Correspondence to: R. A. Goldberg (richard.a.goldberg@nasa.gov) payloads. These were designed to measure plasma and neutral turbulence within the MLT. The summer program exhibited a number of indications of significant departures of the mean wind and temperature structures from "normal" polar summer conditions, including an unusually warm mesopause and a slowing of the formation of polar mesospheric summer echoes (PMSE) and noctilucent clouds (NLC). This was suggested to be due to enhanced planetary wave activity in the Southern Hemisphere and a surprising degree of interhemispheric coupling. The winter program was designed to study the upward propagation and penetration of mountain waves from northern Scandinavia into the MLT at a site favored for such penetration. As the major response was expected to be downstream (east) of Norway, these motions were measured with similar rocket sequences to those used in the summer campaign, but this time at Esrange. However, a major polar stratospheric warming just prior to the rocket launch window induced small or reversed stratospheric zonal winds, which prevented mountain wave penetration into the mesosphere. Instead, mountain waves encountered critical levels at lower altitudes and the observed wave structure in the mesosphere originated from other sources. For example, a large-amplitude semidiurnal tide was observed in the mesosphere on 28 and 29 January, and appears to have contributed to significant in...

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Polar mesosphere winter echoes during MaCWAVE

Cited by 43 publications

References 27 publications

Statistical characteristics of PMWE observations by the EISCAT VHF radar

Statistical characteristics of PMWE observations by the EISCAT VHF radar

Ionization and NO production in the polar mesosphere during high-speed solar wind streams: model validation and comparison with NO enhancements observed by Odin-SMR

The MaCWAVE program to study gravity wave influences on the polar mesosphere

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