印度尼西亚贯穿流（the Indonesian Throughflow，ITF）是通过印度尼西亚海连接热带太平洋和热带印度洋的低纬环流系统，它不仅是热带西太平洋低纬度西边界流的一部分，也是全球大洋输送带的一部分。研究表明，ITF对印度洋和太平洋之间...印度尼西亚贯穿流（the Indonesian Throughflow，ITF）是通过印度尼西亚海连接热带太平洋和热带印度洋的低纬环流系统，它不仅是热带西太平洋低纬度西边界流的一部分，也是全球大洋输送带的一部分。研究表明，ITF对印度洋和太平洋之间的质量、热量和盐度收支都起到了重要的作用，因此对热带气候有重要的影响意义。但是，缺少对印度尼西亚海域直接的、持续的观测，在很大程度上限制了我们对ITF的理解。数值模式作为一种有效的辅助手段，可以重现ITF的环流结构，弥补观测不足。对ITF的相关研究中，为了分辨印度尼西亚海的复杂地形，普遍使用高分辨率的大洋环流模式，因此在利用模式来研究ITF物理机制之前，系统评估模式性能是我们不可缺少的步骤。展开更多
利用INSTANT(The International Nusantara Stratification and Transport,努沙登加拉层结及输运的国际联合观测计划)计划所测得的流场数据,研究了ITF(Indonesian Throughflow,印度尼西亚贯穿流)在主要流出海峡——龙目海峡(Lombok Stra...利用INSTANT(The International Nusantara Stratification and Transport,努沙登加拉层结及输运的国际联合观测计划)计划所测得的流场数据,研究了ITF(Indonesian Throughflow,印度尼西亚贯穿流)在主要流出海峡——龙目海峡(Lombok Strait)、翁拜海峡(Ombai Strait)和帝汶海峡(Timor Passage)随深度和时间的变化,并对表层和温跃层的流速进行了功率谱分析。研究发现,ITF流场在龙目和翁拜海峡表层有显著的年循环,在季风转换期间各个层次上海流都会出现反转,从印度洋流向海峡内;而帝汶海峡在300m以下出现反转流。3个海峡的表层流都以年周期为主,温跃层的流以半年变化为主,并且都有丰富的季节内变化。高频部分,除了在龙目海峡表层K1日潮占优外,各海峡均以M2半日潮为主。展开更多
Detailed mineral magnetic measurements,integrated with grain-size distribution and X-ray diffraction(XRD) analyses,were made on the marine sediments of Core MD98-2172,retrieved from the Eastern Timor Sea.Values of mag...Detailed mineral magnetic measurements,integrated with grain-size distribution and X-ray diffraction(XRD) analyses,were made on the marine sediments of Core MD98-2172,retrieved from the Eastern Timor Sea.Values of magnetic susceptibility in this core drop sharply down-core from-3.85 m deep below sediment/water interface and are very low at-5.35 m.However,both XRD and grain-size distribution results show no sudden change in terrigenous input during sedimentation.Mineral magnetic results indicate that the depth of-3.85 m may be an oxic/anoxic boundary.Therefore,the sediments below-3.85 m have been subjected to intense reductive diagenesis,whereas the sediments above-3.85 m are seldom affected.The magnetic properties of the sediments shallower than 3.85 m are dominated by pseudo-single domain(PSD) magnetite,with little down-core variation in its content and grain size.Below-3.85 m,the magnetic mineral assemblages that have survived in the sediments may record different stages of the reductive diagenesis:(1) the sediments from the 3.85-5.35 m interval are at the stage of iron oxide reduction;PSD magnetite is the major magnetic contributor,but it becomes less abundant and coarser down-core;(2) the sediments below-5.35 m are at the stage of sulphate reduction;ferrimagnetic minerals almost vanish and paramagnetic minerals contribute to down-core susceptibility variations,including pyrite as evidenced by high-temperature magnetic susceptibility measurements.However,the susceptibility variations below-5.35 m of Core MD98-2172 show obvious periodicity,despite the intense effect of reductive diagenesis.Furthermore,the down-core susceptibility variations are coincident with fluctuations in the quantity of fine detrital particles(<8 μm),which may come mainly from the advection of the Indonesia Throughflow(ITF) and/or river input from Timor.Therefore,for Core MD98-2172,susceptibility variation below-5.35 m,which potentially correspond to fluctuations in the quantity of fine particles,may record the histories of the development of the ITF and precipitation on Timor.展开更多
文摘印度尼西亚贯穿流（the Indonesian Throughflow，ITF）是通过印度尼西亚海连接热带太平洋和热带印度洋的低纬环流系统，它不仅是热带西太平洋低纬度西边界流的一部分，也是全球大洋输送带的一部分。研究表明，ITF对印度洋和太平洋之间的质量、热量和盐度收支都起到了重要的作用，因此对热带气候有重要的影响意义。但是，缺少对印度尼西亚海域直接的、持续的观测，在很大程度上限制了我们对ITF的理解。数值模式作为一种有效的辅助手段，可以重现ITF的环流结构，弥补观测不足。对ITF的相关研究中，为了分辨印度尼西亚海的复杂地形，普遍使用高分辨率的大洋环流模式，因此在利用模式来研究ITF物理机制之前，系统评估模式性能是我们不可缺少的步骤。
文摘利用INSTANT(The International Nusantara Stratification and Transport,努沙登加拉层结及输运的国际联合观测计划)计划所测得的流场数据,研究了ITF(Indonesian Throughflow,印度尼西亚贯穿流)在主要流出海峡——龙目海峡(Lombok Strait)、翁拜海峡(Ombai Strait)和帝汶海峡(Timor Passage)随深度和时间的变化,并对表层和温跃层的流速进行了功率谱分析。研究发现,ITF流场在龙目和翁拜海峡表层有显著的年循环,在季风转换期间各个层次上海流都会出现反转,从印度洋流向海峡内;而帝汶海峡在300m以下出现反转流。3个海峡的表层流都以年周期为主,温跃层的流以半年变化为主,并且都有丰富的季节内变化。高频部分,除了在龙目海峡表层K1日潮占优外,各海峡均以M2半日潮为主。
基金Supported by the National Basic Research Program of China (No. 2006CB701400)the National Natural Science Foundation of China (Nos. 40621002,40974035,40272074)Projects of Ministry of Education of China ("111" Project B07011,IRT0546)
文摘Detailed mineral magnetic measurements,integrated with grain-size distribution and X-ray diffraction(XRD) analyses,were made on the marine sediments of Core MD98-2172,retrieved from the Eastern Timor Sea.Values of magnetic susceptibility in this core drop sharply down-core from-3.85 m deep below sediment/water interface and are very low at-5.35 m.However,both XRD and grain-size distribution results show no sudden change in terrigenous input during sedimentation.Mineral magnetic results indicate that the depth of-3.85 m may be an oxic/anoxic boundary.Therefore,the sediments below-3.85 m have been subjected to intense reductive diagenesis,whereas the sediments above-3.85 m are seldom affected.The magnetic properties of the sediments shallower than 3.85 m are dominated by pseudo-single domain(PSD) magnetite,with little down-core variation in its content and grain size.Below-3.85 m,the magnetic mineral assemblages that have survived in the sediments may record different stages of the reductive diagenesis:(1) the sediments from the 3.85-5.35 m interval are at the stage of iron oxide reduction;PSD magnetite is the major magnetic contributor,but it becomes less abundant and coarser down-core;(2) the sediments below-5.35 m are at the stage of sulphate reduction;ferrimagnetic minerals almost vanish and paramagnetic minerals contribute to down-core susceptibility variations,including pyrite as evidenced by high-temperature magnetic susceptibility measurements.However,the susceptibility variations below-5.35 m of Core MD98-2172 show obvious periodicity,despite the intense effect of reductive diagenesis.Furthermore,the down-core susceptibility variations are coincident with fluctuations in the quantity of fine detrital particles(<8 μm),which may come mainly from the advection of the Indonesia Throughflow(ITF) and/or river input from Timor.Therefore,for Core MD98-2172,susceptibility variation below-5.35 m,which potentially correspond to fluctuations in the quantity of fine particles,may record the histories of the development of the ITF and precipitation on Timor.
