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arXiv 1001.3772astro-ph.IM
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冰穹A、冰穹C和South Pole上空大气性质的比较

Comparison of the atmospheric properties above Dome A, Dome C, and the South Pole

S. Hagelin, E. Masciadri, F. Lascaux, J. Stoesz

摘要:

对南极内陆高原三个观测点的大气特性进行了天文学应用研究,计算了欧洲中期天气预报中心(ECMWF)全年(2005年)分析数据的月中值,从而覆盖了所有季节。在每年的时间尺度上从圆顶C和南极延伸的无线电探空被用来验证在自由大气中的分析的可靠性,并研究在第一个100米的风速,因为分析数据不是最佳的这个高度范围。自由大气中的风速是从ECMWF对所有三个站点的分析中获得的。冬季高层大气风速的强弱似乎与地点距极高中心的距离有关。Richardson数被用来研究自由大气的稳定性,从而研究在这三个位置上触发热力学不稳定性的概率。我们发现,在绝大多数情况下,在南极高原内部的自由大气比中纬度地区更稳定。给出这些数据,我们可以得到一个排名的三个网站相对于风速,在自由大气中,以及在表面层,相对于大气的稳定性,使用理查森数。

英文摘要:

The atmospheric properties above three sites on the Internal Antarctic Plateau are investigated for astronomical applications calculating the monthly median of the analysis-data from ECMWF (European Centre for Medium-Range Weather Forecasts) for an entire year (2005) thus covering all seasons. Radiosoundings extended on a yearly time scale from Dome C and the South Pole are used to verify the reliability of the analyses in the free atmosphere and to study the wind speed in the first 100 m as the analysis-data are not optimized for this altitude-range. The wind speed in the free atmosphere is obtained from the ECMWF analyses from all three sites. It appears that the strength of the wind speed in the upper atmosphere in winter is correlated to the distance of the site from the centre of the polar high. The Richardson number is employed to investigate the stability of the free atmosphere and, consequently, the probability to trigger thermodynamic instabilities above the three sites. We find that, in a large majority of the cases, the free atmosphere over the Internal Antarctic Plateau is more stable than at mid-latitude sites. Given these data we can obtain a ranking of the three sites with respect to wind speed, in the free atmosphere as well as in the surface layer, and with respect to the stability of the atmosphere, using the Richardson number.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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