The SPARC Intercomparison of Middle-Atmosphere Climatologies

Randel, William J.; Udelhofen, Petra M.; Fleming, Eric L.; Geller, Marvin A.; Gelman, M. E.; Hamilton, Kevin; Karoly, David J.; Ortland, D. A.; Pawson, S.; Swinbank, Richard; Wu, Fei; Baldwin, Mark P.; Chanin, Marie-Lise; Philippe, Keckhut; Labitzke, K.; Remsberg, Ellis E.; Simmons, A. J.; Wu, Dong L.

doi:10.1175/1520-0442(2004)017<0986:tsiomc>2.0.co;2

Cited by 220 publications

(231 citation statements)

References 38 publications

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“…11. MIPAS PSC detections are shown for the altitude range of about 18-22 km (450-550 K potential temperature), which coincides with the range of polar vortex temperature minima (Randel et al, 2004) and PSC occurrence frequency maxima (Poole and Pitts, 1994;Spang et al, 2005;Pitts et al, 2009) during the course of the polar winter. To help link the PSC observations to gravity wave activity, further information was added to the maps following Spang et al (2016).…”

Section: A Survey Of Gravity-wave-induced Psc Formation Eventssupporting

confidence: 66%

A decadal satellite record of gravity wave activity in the lower stratosphere to study polar stratospheric cloud formation

et al. 2017

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Abstract. Atmospheric gravity waves yield substantial small-scale temperature fluctuations that can trigger the formation of polar stratospheric clouds (PSCs). This paper introduces a new satellite record of gravity wave activity in the polar lower stratosphere to investigate this process. The record is comprised of observations of the Atmospheric Infrared Sounder (AIRS) aboard NASA's Aqua satellite from January 2003 to December 2012. Gravity wave activity is measured in terms of detrended and noise-corrected 15 µm brightness temperature variances, which are calculated from AIRS channels that are the most sensitive to temperature fluctuations at about 17-32 km of altitude. The analysis of temporal patterns in the data set revealed a strong seasonal cycle in wave activity with wintertime maxima at mid-and high latitudes. The analysis of spatial patterns indicated that orography as well as jet and storm sources are the main causes of the observed waves. Wave activity is closely correlated with 30 hPa zonal winds, which is attributed to the AIRS observational filter. We used the new data set to evaluate explicitly resolved temperature fluctuations due to gravity waves in the European Centre for Medium-Range Weather Forecasts (ECMWF) operational analysis. It was found that the analysis reproduces orographic and non-orographic wave patterns in the right places, but that wave amplitudes are typically underestimated by a factor of 2-3. Furthermore, in a first survey of joint AIRS and Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) satellite observations, nearly 50 gravity-wave-induced PSC formation events were identified. The survey shows that the new AIRS data set can help to better identify such events and more generally highlights the importance of the process for polar ozone chemistry.

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Section: A Survey Of Gravity-wave-induced Psc Formation Eventssupporting

confidence: 66%

A decadal satellite record of gravity wave activity in the lower stratosphere to study polar stratospheric cloud formation

et al. 2017

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“…From 1976 onward the 5 • × 5 • resolution is available. Detailed comparisons of these analyses can be found elsewhere (Manney et al, 2003(Manney et al, , 2005Randel et al, 2004;Labitzke and Kunze, 2005). The PSC v intercomparison is summarised in Figure A1.…”

Section: Discussionmentioning

confidence: 99%

Variability of the Northern Hemisphere polar stratospheric cloud potential: the role of North Pacific disturbances

Orsolini

Karpechko

Nikulin

2009

Quart J Royal Meteoro Soc

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ABSTRACT:The potential of the Arctic stratosphere to sustain the formation of Polar Stratospheric Clouds (PSCs) is a key factor in determining the amount of ozone destroyed each winter, and is often measured as a 'PSC volume'. The latter quantity has been shown to closely follow a near-linear compact relationship with winter-averaged column ozone loss, and displays a high variability from monthly to decadal time-scales. We examine the connection between meteorological conditions in the troposphere and the variability of lower polar stratospheric temperatures over the last four decades, and specifically, conditions leading to a high PSC volume. In addition to the well-established connection between the North Atlantic Oscillation (NAO) and the polar vortex, we demonstrate the large influence of precursory disturbances over the North Pacific and the Far East, the region of maximum climatological upward wave activity flux. Namely, very high monthly PSC volume (in the top 12%) predominantly follows the development of positive tropospheric height anomalies over the Far East, which lead to a weakening of the background planetary wave trough, and lessened upward wave activity flux into the stratosphere. Precursory anomalies over the Far East are reminiscent of East Asian monsoon amplification episodes.

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“…However, it is difficult to derive the larger scale wind fields using the geostrophic assumption in the tropics because the Coriolis parameter vanishes at the equator and the solutions become numerically unstable (Hamilton, 1998;Žagar et al, 2004;Polavarapu et al, 2005). For instance, significant differences are seen between wind climatologies derived from mass balance (Fleming et al, 1990;Randel et al, 2004). A further complication in the middle atmosphere is that the small errors from the lower atmosphere propagate vertically and amplify strongly in the upper stratosphere and mesosphere (Nezlin et al, 2009;Alexander et al, 2010).…”

Section: P Baron Et Al: Smiles Windsmentioning

confidence: 99%

Observation of horizontal winds in the middle-atmosphere between 30° S and 55° N during the northern winter 2009–2010

et al. 2013

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Abstract. Although the links between stratospheric dynamics, climate and weather have been demonstrated, direct observations of stratospheric winds are lacking, in particular at altitudes above 30 km. We report observations of winds between 8 and 0.01 hPa (~35–80 km) from October 2009 to April 2010 by the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on the International Space Station. The altitude range covers the region between 35–60 km where previous space-borne wind instruments show a lack of sensitivity. Both zonal and meridional wind components were obtained, though not simultaneously, in the latitude range from 30° S to 55° N and with a single profile precision of 7–9 m s–1 between 8 and 0.6 hPa and better than 20 m s–1 at altitudes above. The vertical resolution is 5–7 km except in the upper part of the retrieval range (10 km at 0.01 hPa). In the region between 1–0.05 hPa, an absolute value of the mean difference < 2 m s–1 is found between SMILES profiles retrieved from different spectroscopic lines and instrumental settings. Good agreement (absolute value of the mean difference of ~2 m s–1) is also found with the European Centre for Medium-Range Weather Forecasts (ECMWF) analysis in most of the stratosphere except for the zonal winds over the equator (difference > 5 m s−1). In the mesosphere, SMILES and ECMWF zonal winds exhibit large differences (> 20 m s–1), especially in the tropics. We illustrate our results by showing daily and monthly zonal wind variations, namely the semi-annual oscillation in the tropics and reversals of the flow direction between 50–55° N during sudden stratospheric warmings. The daily comparison with ECMWF winds reveals that in the beginning of February, a significantly stronger zonal westward flow is measured in the tropics at 2 hPa compared to the flow computed in the analysis (difference of ~20 m s–1). The results show that the comparison between SMILES and ECMWF winds is not only relevant for the quality assessment of the new SMILES winds, but it also provides insights on the quality of the ECMWF winds themselves. Although the instrument was not specifically designed for measuring winds, the results demonstrate that space-borne sub-mm wave radiometers have the potential to provide good quality data for improving the stratospheric winds in atmospheric models.

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The SPARC Intercomparison of Middle-Atmosphere Climatologies

Cited by 220 publications

References 38 publications

A decadal satellite record of gravity wave activity in the lower stratosphere to study polar stratospheric cloud formation

A decadal satellite record of gravity wave activity in the lower stratosphere to study polar stratospheric cloud formation

Variability of the Northern Hemisphere polar stratospheric cloud potential: the role of North Pacific disturbances

Observation of horizontal winds in the middle-atmosphere between 30° S and 55° N during the northern winter 2009–2010

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