Quantification of the intensity of mixing hotspots to clarify the dynamics of the global meridional overturning circulation

量化混合热点强度以阐明全球经向翻转环流的动态

基本信息

批准号：
17340139
负责人：
HIBIYA Toshiyuki
金额：
$ 9.79万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17340139/
关键词：
Diapycnal diffusivity Mixing hotspots Global map Latitudinal dependence Internal tides Microstructure profiler Meridional overturning circulation Expendable current profilers 近慣性流シアー

项目摘要

The un-tethered free-fall microstructure profiler “TurboMAP-D" was used to collect a total of 53 velocity microstructure profiles in the interior of the Pacific Ocean. We found the diapycnal diffusivity at 20°-30°N was roughly in proportional to the logarithm of the locally available energy density of the semidiurnal internal tide and reached more than 10^<-4> m^2s^<-1> near the Izu-Ogasawara Ridge. In contrast, diapycnal diffusivity was found to remain of the order of〜10^<-5> m^2s^<-1> poleward of 30°N and equatorward of 20°N, irrespective of the amount of locally available semidiurnal internal tide energy. We have confirmed that these observed features are consistent with the global map of diapycnal diffusivity in the main thermocline predicted by Hibiya et al. (2006).Using an idealized ocean general circulation model, we next examined the effect of“mixing hotspots", predicted by Hibiya et al. (2006), on the meridional overturning circulation of the Pacific Ocean. We have found that the estimated upwelling in the mixing hotspots is not sufficient to balance deep-water production. In addition, the northward transport of the deep water crossing the equator was found to be much less than estimated from previous current meter moorings and hydrographic surveys. One plausible explanation for these results is that the magnitude of the meridional overturning circulation of the Pacific Ocean has been overestimated from observations. We raise doubts about the validity of previous ocean general circulation models where diapycnal diffusivity is assigned ad hoc to attain the current magnitude suggested from current meter moorings and hydrographic surveys.

非束缚的自由微型结构探测器”用于收集太平洋的埃里尔。我们发现，在20°-30°N处的二细扩散率与半潮湿内部潮汐的局部密度的对数大致相比，大致比半潮汐内部的局部局部密度更高，并重新获得了。 10^-4> Ara山脊。潮汐。我们已经确认观察到的特征与Hibiya预测的主要热阶段的全球型号图相一致。估计在混合热点中的上升是对深水的不满意太平洋已经从观测模型中进行了探测。

项目成果

期刊论文数量（0）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Time aliasing in estimating the wind-induced inertial energy : Comment on“Improved global maps and 54-year history of wind-work on ocean inertial motions"by Matthew. H. Alford

估算风引起的惯性能时的时间混叠：对 Matthew. H. Alford 所著的“改进的全球地图和 54 年风力作用对海洋惯性运动的历史”的评论

DOI：
发表时间：
2005
期刊：
Geophysical Research Letters 32・8
影响因子：
0
作者：
Watanabe;M.;T. Hibiya;T. Enomoto
通讯作者：
T. Enomoto

Microstructure measurements in the mid-depth waters of the North Pacific

DOI：
10.1029/2006gl028695
发表时间：
2007-03-13
期刊：
GEOPHYSICAL RESEARCH LETTERS
影响因子：
5.2
作者：
Nagasawa, Maki;Hibiya, Toshiyuki;Takagi, Shogo
通讯作者：
Takagi, Shogo

Global mapping of wind-induced internal wave energy in the deep ocean (in Japanese)

深海风引起的内波能的全球测绘（日语）

DOI：
发表时间：
2007
期刊：
Cooperative Research Report for 2006, Center for Climate System Research, University of Tokyo
影响因子：
0
作者：
Hibiya;T.;Y. Niwa;T. Endoh;M. Nagasawa;Y. Tanaka;Y. Sugiyama;K. Mohri
通讯作者：
K. Mohri

Assessment of finescale parameterization of deep ocean mixing using a new microstructure profiler.

使用新型微观结构剖面仪评估深海混合的精细参数化。