Coherent tropical-subtropical Holocene see-saw moisture patterns in the Eastern Hemisphere monsoon systems
Coherent tropical-subtropical Holocene see-saw moisture patterns in the Eastern Hemisphere monsoon systems
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东半球季风系统一致的热带-亚热带全新世跷跷板湿度模式
DOI：
10.1016/j.quascirev.2017.06.006
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发表时间：
2017-08
影响因子：
4
通讯作者：
Herzschuh Ulrike
中科院分区：
文献类型：
--
作者：
Wang Yongbo;Bekeschus Benjamin;H;orf Doerthe;Liu Xingqi;Dallmeyer Anne;Herzschuh Ulrike
全球季风（GM）的概念是在现代降水观测的基础上提出的，但其在广泛时间尺度上的应用仍存在争议。在这里，我们提出了一个综合的268个大陆古湿度记录收集的季风系统在东半球，包括东亚季风（EAsM），印度季风（IM），东非季风（EAfM），澳大利亚季风（AuM）涵盖了过去的18,000年。晚冰期至全新世水分变化的总体模式与冰芯和海洋记录推断的一致。相对于过去的10,000年（10 ka），即一个时期，具有高的空间覆盖度，模糊均值聚类分析的水分指数记录连同“谢贝尼”指数揭示了我们的数据集的四个集群。从时间演化和空间分布格局两个方面解释了各聚类的古气候意义。在热带AuM，EAfM和IM地区的主要趋势是在水分条件下，自全新世早期逐渐减少。在EAsM地区的水分变化表现出最大的指数值之间的8和6 ka。然而，位于邻近亚热带地区的记录，即不受热带辐合带影响的地区，与热带季风地区（AuM，EAfM和IM）相比，表现出相反的趋势，即逐渐增加。现代气象数据的分析揭示了与古气候记录相同的空间模式，例如，在季风全面加强的时候，在附近的亚热带地区观察到较低的降水率。我们解释这种模式的影响，一个强大的季风环流抑制空气在附近的亚热带地区的隆起，从而阻碍降水。通过类比现代系统，这意味着在全新世早期强季风时期，季风域内增强的上升气流导致邻近亚热带地区相对较弱的上升气流甚至下降气流，导致与全新世晚期相比降水不足。因此，我们的概念模型集成了区域对比水分变化到全球季风假说。
The concept of a Global Monsoon (GM) has been proposed based on modern precipitation observations, but its application over a wide range of temporal scales is still under debate. Here, we present a synthesis of 268 continental paleo-moisture records collected from monsoonal systems in the Eastern Hemisphere, including the East Asian Monsoon (EAsM), the Indian Monsoon (IM), the East African Monsoon (EAfM), and the Australian Monsoon (AuM) covering the last 18,000 years. The overall pattern of late Glacial to Holocene moisture change is consistent with those inferred from ice cores and marine records. With respect to the last 10,000 years (10 ka), i.e. a period that has high spatial coverage, a Fuzzyc-Means clustering analysis of the moisture index records together with “Xie-Beni” index reveals four clusters of our data set. The paleoclimatic meaning of each cluster is interpreted considering the temporal evolution and spatial distribution patterns. The major trend in the tropical AuM, EAfM, and IM regions is a gradual decrease in moisture conditions since the early Holocene. Moisture changes in the EAsM regions show maximum index values between 8 and 6 ka. However, records located in nearby subtropical areas, i.e. in regions not influenced by the intertropical convergence zone, show an opposite trend compared to the tropical monsoon regions (AuM, EAfM and IM), i.e. a gradual increase. Analyses of modern meteorological data reveal the same spatial patterns as in the paleoclimate records such that, in times of overall monsoon strengthening, lower precipitation rates are observed in the nearby subtropical areas. We explain this pattern as the effect of a strong monsoon circulation suppressing air uplift in nearby subtropical areas, and hence hindering precipitation. By analogy to the modern system, this would mean that during the early Holocene strong monsoon period, the intensified ascending airflows within the monsoon domains led to relatively weaker ascending or even descending airflows in the adjacent subtropical regions, resulting in a precipitation deficit compared to the late Holocene. Our conceptual model therefore integrates regionally contrasting moisture changes into the Global Monsoon hypothesis.
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影响因子：
4.3
作者：
A. Dallmeyer;M. Claussen;N. Fischer;K. Haberkorn;S. Wagner;M. Pfeiffer;Liya Jin;V. Khon;Yang W
通讯作者：
A. Dallmeyer;M. Claussen;N. Fischer;K. Haberkorn;S. Wagner;M. Pfeiffer;Liya Jin;V. Khon;Yang W
影响因子：
12.1
作者：
Yan Zhao;Zicheng Yu
通讯作者：
Yan Zhao;Zicheng Yu
DOI：
10.1191/0959683606hl929rp
发表时间：
2006-04
期刊：
The Holocene
影响因子：
--
作者：
B. Maher;Mengyu Hu
通讯作者：
B. Maher;Mengyu Hu
影响因子：
--
作者：
Pinxian Wang
通讯作者：
Pinxian Wang
影响因子：
1.9
作者：
Maria Ryner;R. Bonnefille;K. Holmgren;A. Muzuka
通讯作者：
Maria Ryner;R. Bonnefille;K. Holmgren;A. Muzuka