Climatic variability and change over southern Africa: a reflection on underlying processes
Climatic variability and change over southern Africa: a reflection on underlying processes
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南部非洲的气候变率和变化：对基本过程的反思
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
M. Jury
中科院分区：
文献类型：
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作者：
S. Mason;M. Jury
南部非洲年降雨量的准周期性已被确定；特别是，大约18年的周期可能与东赤道太平洋和中部印度洋海面温度的年代际变化有关。南海岸的10年周期与驻波3的变化有关。与潮湿和干燥年份相关的大气异常可能与重要的降雨天气系统的频率、强度和持续性的变化有关，并突出了大陆低热强度和西风槽的首选位置和幅度的重要性。厄尔尼诺南方涛动事件以及印度洋和南大西洋的海面温度异常可以影响次大陆的热带和温带大气环流和水分通量，从而对降雨变化产生重大影响。长期气候变化的证据并不像萨赫勒地区那样明确，尽管自 20 世纪 70 年代末以来，一些地区出现了干旱的迹象。气温升高的幅度与半球趋势大致相同，可能归因于温室效应的增强。
Quasi-periodicities in annual rainfall totals over southern Africa have been identified; in particular, an approximately 18-year cycle may be related to interdecadal variability in sea-surface temperatures in the eastern equatorial Pacific and central Indian Oceans. A 10-year cycle along the south coast is related to variability in standing wave 3. Atmospheric anomalies associated with wet and dry years can be related to changes in the frequency, intensity and persistence of important rainfall-producing weather systems and highlight the significance of the strength of the continental heat low and the preferred locations and amplitudes of the westerly troughs. El Niño Southern Oscillation events and sea-surface temperature anomalies in the Indian and South Atlantic Oceans can influence both the tropical and the temperate atmospheric circulation and moisture fluxes over the subcontinent and thus are significant influences on rainfall variability. Evidence for long-term climatic change is not as definitive as in the Sahel, although there are indications of desiccation in some areas since the late-1970s. Increases in temperatures are of approximately the same magnitude as the hemispheric trends and may be attributable to the enhanced greenhouse effect.