Correction [to “Spectral analysis of 10M resolution scalar velocity profiles in the stratosphere”]

Dewan, E. M.; Grossbard, Neil; Quesada, A. F.; Good, R. E.

doi:10.1029/gl011i006p00624

Cited by 25 publications

(9 citation statements)

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“…Nonhydrostatic waves could also transport significant amounts of momentum, but their possible contribution cannot be determined by the theory employed here to analyze the data. We find that the fluxes for periods below 1 h can be comparable to fluxes in longer period bands, despite the well-known tendency for much larger variances at longer periods [Walterscheid et al, 2012;Dewan et al, 1984aDewan et al, , 1984b. Walterscheid et al [2012], assuming a saturated spectrum, calculated that the momentum fluxes in the vicinity of the Antarctic Peninsula provide a significant zonal acceleration of the lower stratosphere.…”

Section: Discussionmentioning

confidence: 58%

Section: Discussionmentioning

confidence: 99%

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Spectral distribution of gravity wave momentum fluxes over the Antarctic Peninsula from Concordiasi superpressure balloon data

et al. 2016

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Gravity waves generated by flow over the steep topography of the Antarctic Peninsula transport significant amounts of zonal and meridional momentum into the stratosphere. Quantitative determination of this transport has been carried out for wave periods of 1 h or greater using data from a previous Antarctic superpressure balloon campaign in austral spring 2005 (VORCORE). The present study uses data from the later Concordiasi campaign (2010) to extend the momentum flux determination to shorter periods. Maps of the vertical fluxes of meridional and zonal momentum are presented for periods down to 12 min. We find that the momentum fluxes for periods below 1 h are comparable to those at longer periods, despite larger variances at longer periods. The momentum fluxes in the vicinity of the peninsula provide a significant zonal acceleration of the lower stratosphere, confirming a conclusion from the VORCORE data. The geographical distribution of fluxes around the peninsula has peaks both leeward and windward of the main terrain features. Numerical simulations suggest that the separate peaks may be related to wave transience caused by unsteady winds over the peninsula. Momentum fluxes comprise a main distribution maximizing at moderate flux values and a secondary distribution maximizing at high values exhibiting a high degree of intermittency. The high flux events account for the largest part of the average flux and suggest that drag parameterizations should take them into account. It is found that waves generated by the jet stream are also a significant source of momentum flux.

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Section: Discussionmentioning

confidence: 58%

Section: Discussionmentioning

confidence: 99%

Spectral distribution of gravity wave momentum fluxes over the Antarctic Peninsula from Concordiasi superpressure balloon data

et al. 2016

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“…As can be seen, the anomalous variability can be very misleading indeed. In the high-resolution spectral analysis of smoke trail data [Dewan et al, 1984[Dewan et al, , 1988] the number of points per profile was of the order of 1000. More precisely, there were 2-5 segments containing about 400 points each.…”

Section: Postdarkeningmentioning

confidence: 99%

“…The discovery [Dewan et al, 1984] that the horizontal velocity vertical wavenumber spectrum appears to be "universal" has inspired a number of theories to be formulated in order to explain this finding. These include those of Dewan and Good [1986], extended by Smith et al [1987], as well as Weinstock [1990], Hines [1991a, b, c], Gardner [1994], and Medvedev and Klaasen [1995].…”

Section: Introductionmentioning

confidence: 99%

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Power spectral artifacts in published balloon data and implications regarding saturated gravity wave theories

Dewan¹,

Grossbard²

2000

J. Geophys. Res.

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Abstract. There are several theories of atmospheric gravity wave power spectral densities (PSDs) which have been published. These, in turn, have inspired numerous experimental tests. The spectra involved are in the class denoted "stochastic, red noise spectra." This means that most of the power is at the low-frequency end and obeys a power law falloff in going to higher frequency. The present paper describes how some published experimental spectra are flawed by an artifact of spectral analysis which has not heretofore been recognized in the literature. It involves both an amplitude fluctuation enhancement and a coupling between spectral amplitude and slope, and it can be avoided only by stringent control of spectral leakage. Because of "trade-off' considerations every data set, depending on its length and signal characteristics, requires a different method of analysis. It is therefore required that PSD analysis programs must be adjusted and tested to fit each situation. For this purpose a simple method is described to simulate data of known general characteristics for test purposes (to avoid the pitfalls). Since the papers by Nastrom et al. [1997] and de la Torre et al. [1997] have the unfortunate artifact in their analyses, their conclusions regarding saturated gravity wave theories should be reexamined. IntroductionThe discovery [Dewan et al., 1984] that the horizontal velocity vertical wavenumber spectrum appears to be "universal" has inspired a number of theories to be formulated in order to explain this finding. These include those of Dewan and Good [1986] waves. In particular, they showed "scatter diagrams" that display correlations between spectral slope and spectral amplitude. As we shall show, their results are contaminated by an artifact not previously discussed in the literature; and this was the original motivation of the present investigation.In recent years, many "canned programs" and "recipes" have been published which perform spectral analysis of experimental data. Unfortunately, such publications give little hint of the vast number of pitfalls that are involved, and they do not give much information about the literature available which might be helpful in this regard. On the basis of our own experience and that of our colleagues, we are very much aware that there is no single procedure (due to trade-offs) which is appropriate to every data set, and that therefore in our joint

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Gravity wave and equatorial wave morphology of the stratosphere derived from long‐term rocket soundings

Eckermann

Hirota²,

Hocking

1995

Quart J Royal Meteoro Soc

136

108

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Fluctuations in vertical profiles of atmospheric temperature and horizontal wind in the 20-60 km altitude range have been isolated from meteorological rocket measurements during 1977-87 at 15 widely separated sites. The seasonal, geographical, and vertical variability of the variance of horizontal velocities, + p, and relative-temperature perturbations, F , were studied. The bulk of the variance of both quantities in the 2-10 km and 2-20 km vertical-wavelength bands was associated with gravity-wave motions, although in-depth study of the wave polarization shows that planetary-scale equatorial wave modes contribute to the variance at equatorial sites. Annual mean variances varied widely among -the 15 stations, suggesting appreciable geographical variability in stratospheric wave activity. Whereas u'* + u '~ values generally increased significantly with altitude throughout the stratosphere, F values grew less substantially and often decreased with altitude at upper heights. Rotations of wave-velocity phasors with height were always more frequently clockwise than anticlockwise in the northern hemisphere, consistent with upward-propagating wave energy, yet these percentages (>50%) showed a marked semi-annual variation, with equinoctial maxima and minima at the solstices. At high latitudes (-50°N-80"N) variances exhibited a strong annual variation, with the minimum in summer and a strong peak during winter at both lower (20-40 km) and upper (40-60 km) heights. The annual variance cycle attenuated somewhat at mid-latitudes (-25"N-40"N), and a strong peak in August dominated the d 2 + variations at 4 0 4 0 km. The peak was also evident in p, but was smaller relative to the winter peak. At low latitudes (-15"N-25'") the wave morphology was broadly similar to that at mid-latitudes, apart from an additional upper-level peak in the variance in May. This peak in May occurred in some years but not in others at mid-latitude stations. At the equatorial stations (-10"N-10%) the low-level variance showed little systematic seasonal variability, but exhibited clear modulation over a quasi-two-year period. Much of this variance was consistent with the Kelvin modes thought to drive the eastward phase of the stratospheric quasibiennial oscillation (QBO). However, the uniform east-west alignment of waves was inconsistent with the expected polarization of the mixed Rossby-gravity wave mode which is believed to drive the westward phase of the QBO. At 40-60 km, the variance was strongly attenuated around April-May and November, when both 8 + ? and Fdecreased with height around the 40-45 km range, indicating that wave dissipation occurs here. This produced a semi-annual variation at upper heights, with maxima around January and July, which may contribute significantly to the semi-annual wave driving of the equatorial upper stratosphere. Polarization studies showed that this variance in the 2-10 km band was mostly due to gravity waves, although equatorial modes contributed during December-February .

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Correction [to “Spectral analysis of 10M resolution scalar velocity profiles in the stratosphere”]

Cited by 25 publications

References 1 publication

Spectral distribution of gravity wave momentum fluxes over the Antarctic Peninsula from Concordiasi superpressure balloon data

Spectral distribution of gravity wave momentum fluxes over the Antarctic Peninsula from Concordiasi superpressure balloon data

Power spectral artifacts in published balloon data and implications regarding saturated gravity wave theories

Gravity wave and equatorial wave morphology of the stratosphere derived from long‐term rocket soundings

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