本文基于观测资料和LICOM2.0模拟结果的分析研究,简要介绍讨论了太平洋—印度洋海温(异常)联合模(PIOAM)的存在、特征、演变及其影响等问题。热带太平洋—印度洋区域乃至全球范围的海表温度异常(SSTA)资料进行EOF分解,都清楚表明其第一...本文基于观测资料和LICOM2.0模拟结果的分析研究,简要介绍讨论了太平洋—印度洋海温(异常)联合模(PIOAM)的存在、特征、演变及其影响等问题。热带太平洋—印度洋区域乃至全球范围的海表温度异常(SSTA)资料进行EOF分解,都清楚表明其第一分量在热带太平洋—印度洋的空间形态与太平洋—印度洋海温(异常)联合模(PIOAM)非常相似,说明PIOAM是热带太平洋—印度洋实实在在存在的一种海温异常模态。对应PIOAM的正、负位相,热带印度洋和西太平洋地区的夏季(JJA)850 h Pa距平风场有近乎相反的异常流场形势;对流层低层的Walker环流支和亚洲夏季风都出现了不同特征的(近乎相反)异常;在PIOAM正(负)位相将使得100 h Pa的南亚高压位置偏东(西)。对热带太平洋和印度洋温跃层曲面上的海温异常(为了方便将其称为SOTA)进行EOF分解,发现其第一模态也是一个三极子模态,即当赤道中西印度洋大部分海域与赤道中东太平洋大部分海域偏暖(偏冷)时,赤道东印度洋和赤道西太平洋大部分海域则偏冷(偏暖);它与太平洋—印度洋表层的PIOAM十分类似,也表明PIOAM在海洋次表层也是存在的。高分辨海洋环流模式LICOM2.0的模拟结果,无论是对太平洋—印度洋表层还是次表层的PIOAM的特征和演变都刻画得很好,这从另一个角度进一步说明PIOAM是热带太平洋—印度洋实际存在的一种海温变化模态。PIOAM正、负位相不仅对亚洲及西太平洋地区的天气气候有非常不一样的影响(不少地方有反向的特征),还会对南北美洲和非洲一些地区产生不同影响;而且其影响与单独的厄尔尼诺(El Ni?o)及印度洋偶极子(IOD)都不尽相同。展开更多
The authors investigate biases in the freshwater flux（FWF） of CORE.v2—a common data-set for stand-alone ocean models—based on the results of a set of experiments using an OGCM. The authors identify freshening bias...The authors investigate biases in the freshwater flux（FWF） of CORE.v2—a common data-set for stand-alone ocean models—based on the results of a set of experiments using an OGCM. The authors identify freshening biases in the FWF in the subtropical regions of the North Pacific, South Pacific, and South Atlantic, which may be caused by the weak surface wind, high specific humidity,or high precipitation in the CORE.v2 data. The authors also find biases in sea surface salinity that are caused by ocean dynamics, such as in the North Atlantic, and that cannot be corrected by correcting surface forcing.展开更多
The performance of the eddy-resolving LICOM2.0 in simulating the Indonesian Throughflow has been evaluated against the INSTANT data in the present study.The mean vertical structures of the along strait velocities are ...The performance of the eddy-resolving LICOM2.0 in simulating the Indonesian Throughflow has been evaluated against the INSTANT data in the present study.The mean vertical structures of the along strait velocities are simulated well in LICOM2.0,but the large velocities at the bottom of the Lifamatola Passage and the Timor Passage cannot be reproduced by LICOM2.0.The causes are considered to be both the errors in the topography and the tidal mixing at the bottom.Despite several biases in the mean velocities,the mean inflow and outflow volume transports in LICOM2.0 are almost identical to the INSTANT data.Compared with the lower resolution LICOM,the most significant improvement is the better simulation of the partitions of the inflow and outflow transports in individual straits.The outflow for low-resolution LICOM is mainly through the Ombai and Lombok Strait,whereas that for LICOM2.0 is mainly through the Timor Passage.The variability of the vertical structure of velocities and the volume transport are also investigated.LICOM2.0 overestimates the magnitude of the upper-layer currents and the amplitude of the variation.We also found that the largest correlation coefficient occurs in the shallowest strait,the Lombok,whereas the lowest occurs in the Timor Passage,especially in the upper layer.The latter may be caused by the unrealistic transport through the Torres Strait in LICOM2.0.展开更多
文摘本文基于观测资料和LICOM2.0模拟结果的分析研究,简要介绍讨论了太平洋—印度洋海温(异常)联合模(PIOAM)的存在、特征、演变及其影响等问题。热带太平洋—印度洋区域乃至全球范围的海表温度异常(SSTA)资料进行EOF分解,都清楚表明其第一分量在热带太平洋—印度洋的空间形态与太平洋—印度洋海温(异常)联合模(PIOAM)非常相似,说明PIOAM是热带太平洋—印度洋实实在在存在的一种海温异常模态。对应PIOAM的正、负位相,热带印度洋和西太平洋地区的夏季(JJA)850 h Pa距平风场有近乎相反的异常流场形势;对流层低层的Walker环流支和亚洲夏季风都出现了不同特征的(近乎相反)异常;在PIOAM正(负)位相将使得100 h Pa的南亚高压位置偏东(西)。对热带太平洋和印度洋温跃层曲面上的海温异常(为了方便将其称为SOTA)进行EOF分解,发现其第一模态也是一个三极子模态,即当赤道中西印度洋大部分海域与赤道中东太平洋大部分海域偏暖(偏冷)时,赤道东印度洋和赤道西太平洋大部分海域则偏冷(偏暖);它与太平洋—印度洋表层的PIOAM十分类似,也表明PIOAM在海洋次表层也是存在的。高分辨海洋环流模式LICOM2.0的模拟结果,无论是对太平洋—印度洋表层还是次表层的PIOAM的特征和演变都刻画得很好,这从另一个角度进一步说明PIOAM是热带太平洋—印度洋实际存在的一种海温变化模态。PIOAM正、负位相不仅对亚洲及西太平洋地区的天气气候有非常不一样的影响(不少地方有反向的特征),还会对南北美洲和非洲一些地区产生不同影响;而且其影响与单独的厄尔尼诺(El Ni?o)及印度洋偶极子(IOD)都不尽相同。
基金supported by the National Basic Research Program of China(grant number 2013CB956204)the Strategic Priority Research Program of the Chinese Academy of Sciences(grant numbers XDA11010403 and XDA11010304)
文摘The authors investigate biases in the freshwater flux（FWF） of CORE.v2—a common data-set for stand-alone ocean models—based on the results of a set of experiments using an OGCM. The authors identify freshening biases in the FWF in the subtropical regions of the North Pacific, South Pacific, and South Atlantic, which may be caused by the weak surface wind, high specific humidity,or high precipitation in the CORE.v2 data. The authors also find biases in sea surface salinity that are caused by ocean dynamics, such as in the North Atlantic, and that cannot be corrected by correcting surface forcing.
基金supported by the National Basic Research Program of China(2010CB951904 and 2013CB956204)the National Natural Science Foundation of China(41275084,41075059 and 41023002)the Strategic Priority Research Program–Climate Change:Carbon Budget and Related Issues of the Chinese Academy of Sciences(XDA05110302)
文摘The performance of the eddy-resolving LICOM2.0 in simulating the Indonesian Throughflow has been evaluated against the INSTANT data in the present study.The mean vertical structures of the along strait velocities are simulated well in LICOM2.0,but the large velocities at the bottom of the Lifamatola Passage and the Timor Passage cannot be reproduced by LICOM2.0.The causes are considered to be both the errors in the topography and the tidal mixing at the bottom.Despite several biases in the mean velocities,the mean inflow and outflow volume transports in LICOM2.0 are almost identical to the INSTANT data.Compared with the lower resolution LICOM,the most significant improvement is the better simulation of the partitions of the inflow and outflow transports in individual straits.The outflow for low-resolution LICOM is mainly through the Ombai and Lombok Strait,whereas that for LICOM2.0 is mainly through the Timor Passage.The variability of the vertical structure of velocities and the volume transport are also investigated.LICOM2.0 overestimates the magnitude of the upper-layer currents and the amplitude of the variation.We also found that the largest correlation coefficient occurs in the shallowest strait,the Lombok,whereas the lowest occurs in the Timor Passage,especially in the upper layer.The latter may be caused by the unrealistic transport through the Torres Strait in LICOM2.0.
