Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1002/2017JD026697 |
An influence of extreme southern hemisphere cold surges on the North Atlantic Subtropical High through a shallow atmospheric circulation | |
Bowerman, A. R.1; Fu, R.2; Yin, L.1; Fernando, D. N.3; Arias, P. A.4; Dickinson, R. E.1 | |
2017-10-16 | |
发表期刊 | JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES |
ISSN | 2169-897X |
EISSN | 2169-8996 |
出版年 | 2017 |
卷号 | 122期号:19 |
文章类型 | Article |
语种 | 英语 |
国家 | USA; Colombia |
英文摘要 | Previous studies have attributed interhemisphere influences of the atmosphere to the latitudinal propagation of planetary waves crossing the equator, to the triggering of equatorial Kelvin waves, or to monsoonal circulation. Over the American-Atlantic sector, such cross-equatorial influences rarely occur during boreal summer due to unfavorable atmospheric conditions. We have observed that an alternative mechanism provides an interhemisphere influence. When episodes of extreme cold surges and upper tropospheric westerly winds occur concurrently over southern hemisphere Amazonia, cold surges from extratropical South America can penetrate deep into southern Amazonia. Although they do not appear to influence upper tropospheric circulation of the northern hemisphere, extremely strong southerly cross-equatorial advection (>2 sigma standard deviations, or 2) of cold and dense air in the lower troposphere can reach as least 10 degrees N. Such cold advection increases the northward cross-equatorial pressure gradient in the lower to middle troposphere, thus shallow northerly return flow below 500hPa. This return flow and the strong lower tropospheric southerly cross-equatorial flow form an anomalous shallow meridional circulation spanning from southern Amazonia to the subtropical North Atlantic, with increased geopotential height anomalies exceeding +1 sigma to at least 18 degrees N. It projects onto the southern edge of the North Atlantic Subtropical High (NASH), increasing its pressure and leading to equatorward expansion of NASH's southern boundary. These anomalies enhance the NASH, leading to its equatorward expansion. These extreme cold surges can potentially improving the predictability of weather patterns of the tropical and subtropical Atlantic, including the variability of the NASH's southern edge. |
领域 | 气候变化 |
收录类别 | SCI-E |
WOS记录号 | WOS:000413675900001 |
WOS关键词 | LARGE-SCALE MOTIONS ; EQUATORIAL RESPONSE ; SEASONAL CYCLE ; UNITED-STATES ; AMERICA ; AIR ; PRECIPITATION ; ANTICYCLONES ; MONSOON ; WAVE |
WOS类目 | Meteorology & Atmospheric Sciences |
WOS研究方向 | Meteorology & Atmospheric Sciences |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/32182 |
专题 | 气候变化 |
作者单位 | 1.Univ Texas Austin, Dept Geol Sci, Austin, TX USA; 2.Univ Calif Los Angeles, Dept Atmospher & Ocean Sci, Los Angeles, CA 90095 USA; 3.Texas Water Dev Board, Austin, TX USA; 4.Univ Antioquia, Escuela Ambiental, Grp Ingn & Gest Ambiental 4, Medellin, Colombia |
推荐引用方式 GB/T 7714 | Bowerman, A. R.,Fu, R.,Yin, L.,et al. An influence of extreme southern hemisphere cold surges on the North Atlantic Subtropical High through a shallow atmospheric circulation[J]. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES,2017,122(19). |
APA | Bowerman, A. R.,Fu, R.,Yin, L.,Fernando, D. N.,Arias, P. A.,&Dickinson, R. E..(2017).An influence of extreme southern hemisphere cold surges on the North Atlantic Subtropical High through a shallow atmospheric circulation.JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES,122(19). |
MLA | Bowerman, A. R.,et al."An influence of extreme southern hemisphere cold surges on the North Atlantic Subtropical High through a shallow atmospheric circulation".JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 122.19(2017). |
条目包含的文件 | 条目无相关文件。 |
除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。
修改评论