The decline of winter monsoon velocity in the South China Sea through the 20th century: Evidence from the Sr/Ca records in corals
The decline of winter monsoon velocity in the South China Sea through the 20th century: Evidence from the Sr/Ca records in corals
复制标题
20世纪南海冬季风速的下降：珊瑚中Sr/Ca记录的证据
DOI：
10.1016/j.gloplacha.2008.05.003
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发表时间：
2008-08-01
影响因子：
3.9
通讯作者：
Zartman, Robert E.
中科院分区：
文献类型：
--
作者：
Liu, Yi;Peng, Zicheng;Zartman, Robert E.
采自海南岛东海岸龙湾（19 ° 20 ′ N，110 ° 39 ′ E）的现代块状滨珊瑚。垂直于生长轴将珊瑚切成代表年生长的双密度带盘。通过电感耦合等离子体原子发射光谱法分析样品的Sr/Ca比。冬季海表温度（SST）的历史重建使用的Sr/Ca比在冬季带的珊瑚。南海中部西沙冬季海温与冬季风风速的相关性较弱，相关系数为0.19。南海北方海南龙湾珊瑚冬季SST与WMV的相关性较好（r=0.40）。有趣的是，我们发现两个站点（西沙和龙湾湾，海南）的冬季SST的差异（X-H指数）与WMV呈显著负相关（r=-0.73）。这种负相关可能与冬季强东北季风促使黑潮暖流通过吕宋海峡侵入南海有关。利用我们的珊瑚资料和观测到的WMV之间的关系，计算了87年的冬季风速度（WMVc）。该数据集与1993年至1998年的仪器测量数据相结合，产生了1906年至1998年93年期间的WMVc记录。世纪的WMVc具有显著的年际和年代际变化，整个世纪WMVc呈持续下降趋势，下降速率为-0.02（m/s）/a。最低风速出现在世纪的最后20年。从世纪初到20世纪末，WMVc显著下降了约30%。从南海珊瑚记录中得到的20世纪冬季风速度的下降与大气-海洋环流模式（AOGCMs）模拟的季风对温度升高的响应是一致的。此外，在仪器记录和代理记录中，1976年前后WMV都出现了明显的下降趋势，这与太平洋的许多其他记录相吻合。这一转变可能与太平洋十年涛动在太平洋范围内的变化同时发生相对应。(C)2008 Elsevier B. V.保留所有权利。
A modern massive Porites coral was collected from the Longwan Bay (19 degrees 20'N, 110 degrees 39'E) on the east coast of the Hainan Island, China. The coral was sectioned vertical to the growth axis into discs of double density-bands representing annual growth. The samples were analyzed for the Sr/Ca ratio by inductively coupled plasma atomic emission spectrometry. The history of winter sea-surface temperature (SST) is reconstructed using the Sr/Ca ratio in winter bands of corals. The winter SST at Xisha in the middle of the South China Sea (SCS) is weakly correlated with the instrument-measured winter monsoon velocity (WMV) with a correlation coefficient of 0.19. The winter SST data from corals at Longwan Bay, Hainan, in the northern SCS are moderately correlated with the WMV (r=0.40). Interestingly we found that the difference of winter SSTs between the two sites (Xisha and Longwan Bay, Hainan) (the X-H index) is significantly negatively correlated with the WMV (r=-0.73). This negative correlation may be related to the intrusion of the warm Kuroshio Current into the SCS through the Luzon Strait promoted by the strong northeastern monsoon winds in the winter. Using the relationship between our coralline data and observed WMV, the calculated winter monsoon velocity (WMVc) was obtained for 87 years. This data set in combination with the instrument-measured data between 1993 and 1998 generate a record of WMVc for a period of 93 years from 1906 to 1998. The WMVc in the 20th century shows significant interannual and decadal variability with a trend of persistent decline in the whole 20th century at the rate of decrease of -0.02 (m/s)/a. The lowest wind velocity occurred during the last two decades of the 20th century. The WMVc has decreased significantly by about 30% from the early to the late of 20th century. The 20th century decline of winter monsoon velocity evidenced from the SCS coral records is consistent with the atmosphere-ocean general circulation models (AOGCMs) simulations for monsoon response to increasing temperatures. In addition, an obvious decline shift of WMV around 1976 can be seen in both instrumental and proxy records and it coincides with many other Pacific records. This shift is likely to correspond to a Pacific-wide change in the Pacific Decadal Oscillation occurring at the same time. (C) 2008 Elsevier B.V. All rights reserved.