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Journal of Oceanology and Limnology 2022年第3期40卷 891-906页

作者： Kai LIU Shan GAO Fan WANG Institute of Oceanology Chinese Academy of SciencesQingdao 266071China Center for Ocean Mega-Science Chinese Academy of SciencesQingdao 266071China University of Chinese Academy of Sciences Beijing 100049China China Laboratory for Ocean Dynamics and Climate Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China

The classical Lagrangian particle tracing method is widely used in the evaluation of the ocean annual subduction ***,our analysis indicates that in addition to neglecting the effect of mixing,there are two possible deviations in the method:one is an overestimation due to not considering that the amount of subducted water at the source location may be inadequate during the late winter of the first year when the mixed layer becomes shallow;the other one is an underestimation due to the neglect of the effective subduction caused by strong vertical *** analysis shows that these two deviations mainly exist in the low-latitude subduction areas of the South Pacific and South *** two deviations have very similar distribution areas and can partially off set each ***,the overall deviation is still large,and the maximum relative deviation ratio can reach 50%;therefore,it cannot be ignored.

关键词： subduction rate Lagrangian particle tracing method mixed layer tropical water eastern subtropical mode water

On the Response of the Global subduction rate to Global Warming in Coupled Climate Models

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Advances in Atmospheric Sciences 2014年第1期31卷 211-218页

作者： LIU Chengyan WANG Zhaomin School of Marine Sciences Nanjing University of Information Science & Technology

The response of the global subduction rate to global warming was assessed based on a set of Intergovernmental Panel on Climate Change （IPCC） Fourth Assessment Report （AR4） models. It was found that the subduction rate of the global ocean could be significantly reduced under a warming climate, as compared to a simulation of the present-day climate. The reduction in the subduction volume was quantitatively estimated at about 40 Sv and was found to be= primarily induced by the decreasing of the lateral induction term due to a shallower winter mixed layer depth. The shrinking of the winter mixed layer would result from intensified stratification caused by increased heat input into the ocean under a warming climate. A reduction in subduction associated with the vertical pumping term was estimated at about 5 Sv. F^rther, in the Southern Ocean, a significant reduction in subduction was estimated at around 24 Sv, indicating a substantial contribution to the weakening of global subduction.

关键词： subduction rate mixed layer depth global warming

A study of Indian Ocean Subtropical Mode Water: subduction rate and water characteristics

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Acta Oceanologica Sinica 2016年第1期35卷 38-45页

作者： MA Jie LAN Jian ZHANG Ningning Physical Oceanography Laboratory Ocean University of China College of Oceanic and Atmospheric Sciences Ocean University of China

The annual subduction rate in the South Indian Ocean was calculated by analyzing Simple Ocean Data Assimilation （SODA） outputs in the period of 1950-2008. The subduction rate census for potential density classes showed a peak corresponding to Indian Ocean subtropical mode water （IOSTMW） in the southwestern part of the South Indian Ocean subtropical gyre. The deeper mixed layer depth, the sharper mixed-layer fronts and the associated relatively faster circulation in the present climatology resulted in a larger lateral induction, which primarily dominants the IOSTMW subduction rate, while with only minor contribution from vertical pumping. Without loss of generality, through careful analysis of the water characteristics in the layer of minimum vertical temperature gradient （LMVTG）, the authors suggest that the IOSTMW was identified as a thermostad, with a lateral minimum of low potential vorticity （PV, less than 200× 10^-12 m^-1·s^-1） and a low dT/dz （less than 1.5℃/（100 m））. The IOSTMW within the South Indian Ocean subtropical gyre distributed in the region approximately from 25° to 50° E and from 30° to 39°S. Additionally, the average characteristics （temperature, salinity, potential density） of the mode water were estimated about （16.38 ± 0.29）℃, （35.46 ±0.04）, （26.02 ±0.04） ae over the past 60 years.

关键词： Indian Ocean Subtropical Mode Water subduction rate the layer of minimum vertical temperaturegradient water characteristics

Potential effects of subduction rate in the key ocean on global warming hiatus

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Acta Oceanologica Sinica 2018年第3期37卷 63-68页

作者： CHEN Xingrong LIU Shan CAI Yi ZHANG Shouwen National Marine Environmental Forecasting Center State Oceanic Administration Key Laboratory of Research on Marine Hazards Forecasting National Marine Environmental Forecasting CenterState Oceanic Administration

In this study, the possible effects of subduction rate on global warming hiatus were investigated using Simple Ocean Data Assimilation（SODA） data. This study first analyzed the characteristics of the temporal and spatial distribution of global subduction rate, which revealed that the North Atlantic meridional overturning circulation region and the Antarctic Circumpolar Current region are the two main sea areas with great subduction *** this basis, four key areas were selected to explore the relationship between the local subduction rate and the global mean sea surface temperature. In addition, the reason for the variations in subduction rate was preliminarily explored. The results show good correspondence of the subduction of the key areas in the North Atlantic meridional overturning the circulation region and the Antarctic Circumpolar Current region to the global warming hiatus, with the former leading by about 10 years. The subduction process may be a physical mechanism by which the North Atlantic overturning circulation and the Antarctic Circumpolar Current act on the stagnation of global warming. Advection effect plays an important role in the variations in subduction in the key regions. In the Antarctic Circumpolar Current region, the magnitude of sea surface wind stress is closely related to the local changes in subduction.

关键词： global warming hiatus sea surface temperature inter-decadal variation subduction rate

An assessment of the subduction rate in the CMIP6 historical experiment

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Acta Oceanologica Sinica 2023年第1期42卷 44-60页

作者： Shan Liu Xueyi Jing Xingrong Chen Huijun Wang National Marine Environmental Forecasting Center Ministry of Natural ResourcesBeijing100081China National Supercomputing Center in Wuxi Wuxi214315China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science&TechnologyNanjing210044China Nansen-Zhu International Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing100029China

subduction process is a dynamical bridge for the exchanges of heat between the atmosphere and subsurface ocean water,which is regarded as a central proxy for the ocean climate *** its key indicator in climate signals,it is of importance to examine the ability of a model to simulate the global subduction rate before investigating the climate *** this paper,we evaluated the ability of 21 climate models from Coupled Model Intercomparison Project Phase 6(CMIP6)in simulating the subduction *** general,the simulation ability of the models to the subduction climatology is better than that to the long-term variation *** on the comprehensive analysis of climatology distribution and long-term trend of the subduction rate,GISS-E2-1-G performs better in reproducing the subduction rate climatology and IPSL-CM6A-LR can simulate positive long-term trend for both the global mean subduction rate and the lateral induction term in the Antarctic Circumpolar Current(ACC)***,it is still challenging to capture both the distribution characteristics of the subduction climatology and the long-term temporal trend for the 21 CMIP6 *** addition,the model results demonstrate that,the ACC area is the major region contributing to the long-term trend of the global mean subduction *** analysis in this paper indicates that the poor simulation ability of reproducing the long-term trend of global mean subduction rate might be attributed to the ocean dynamics,for example,the zonal velocity at the bottom mixed layer and zonal gradient of mixed layer depth.

关键词： subduction rate CMIP6 climatology long-term trend

Control of subduction rate on Tonga-Kermadec arc magmatism

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Journal of Oceanology and Limnology 2018年第3期36卷 687-699页

作者： LUO Qing ZHANG Guoliang Key Laboratory of Marine Geology and Environment Institute of OceanologyChinese Academy of SciencesQingdao 266071China University of Chinese Academy of Sciences Beijing 100049China Laboratory of Marine Geology Qingdao National Laboratory for Marine Science and TechnologyQingdao 266071China Deep-Sea Extreme Environment and Life Processes Center Institute of OceanologyChinese Academy of SciencesQingdao 266071China

Dehydration/melting of oceanic crusts during returning to the mantle in subduction zones are related to origin of arc lavas. The factors that influence arc magmatism include compositions of the subducting slabs, mantle wedge and subduction rates. However, distinguishing these factors remains difficult and highly debated. Subducting rate is related to the total mass of inputs and controls thermal structure, thus plays a crucial role in arc magmatism. Here we explore the relationships between geochemical variations of arc lavas and convergence rates(increasing from 46 mm/a to the south to 83 mm/a to the northward) in the Tonga-Kermadec arc system. Data of geochemistry for lava samples from nine islands of this arc system are collected and compiled to investigate the role of subduction rate in arc magmatism. Lavas from the northern Tonga arc with a faster subduction rate show broadly lower concentrations of TiO_2 and highfield-strength elements(HFSEs, e.g. Nb, Ta, Zr, Hf), and higher Ba/Th, U/Th ratios than the Kermadec Arc to the south. Some of the Kermadec lavas show the highest values of Th/Nb ratio. We suggest that the northern Tonga arc with a higher subduction rate has been influenced by a stronger role of subductionreleased fluid, which results in stronger large-ion-lithophile elements(LILEs) and relatively weaker HFSEs contribution. It is interpreted that faster subduction rate tend to create a cooler subduction zone, leading to stronger dehydration subduction slab contribution with, thus, higher LILE/HFSE ratios of arc lavas. The conclusion contributes to a better understanding of arc magmatism, and ultimately the long-term chemical differentiation of the Earth. More supplementary geochemical data along Tonga-Kermadec arc and tests in other arcs are needed.

关键词： subduction rate arc magmatism Tonga-Kermadec Arc

Variability of subduction rates of the subtropical North Pacific mode waters

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Chinese Journal of Oceanology and Limnology 2011年第5期29卷 1131-1141页

作者：胡海波刘秦玉张媛刘伟 School of Atmospheric Sciences Nanjing University Physical Oceanography Laboratory & Ocean-Atmosphere Interaction and Climate Laboratory Ocean University of China School of Atmospheric Sciences Nanjing University of Information Science and Technology Center for Climatic Research and Department of Atmospheric and Oceanic Sciences University of Wisconsin-Madison

The climatology subduction rate for the entire Pacific is known, but the mechanism of interannual to decadal variation remains unclear. In this study, we calculated the annual subduction rates of three types of North Pacific subtropical mode waters using a general circulation model (LICOM1.0) for the period of 1958-2001. The model experiments focused on interannual variations of ocean dynamical processes under daily wind forcings and seasonal heat fluxes. The mode water formation region was defined by a potential vorticity minimum at outcrop locations. The model results show that two subduction rate maxima (>100 m/a) were located in the Subtropical Mode Water (STMW) and the Central Mode Water (CMW) formation regions. These regions are consistent with a climatologically calculated value. The subduction rate in the Eastern Subtropical Mode Water (ESTMW) formation region was smaller at about 75 m/a. The subduction rate shows clear interannual and decadal variations associated with oceanic dynamic variabilities. The average subduction rate of the STMW was much smaller during the period of 1981-1990 compared with other periods, while that of the CMW had a negative anomaly before 1975 and a positive anomaly after 1978. The variability agreed with Ekman and geostrophic advections and mixed layer depths. The interannual variability of the subduction rate for the ESTMW was smallest during 1970-1990, as a result of a weak wind stress curl. This paper explores how interannual signals from the atmosphere are stored in different parts of the ocean, and thus may contribute to a better understanding of feedback mechanisms for the Pacific Decadal Oscillation (PDO) event.

关键词： subduction rate North Pacific subtropical mode water ocean modeling

North Pacific Eastern Subtropical Mode Water simulation and future projection

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Acta Oceanologica Sinica 2015年第3期34卷 25-30页

作者： XIA Ruibin LIU Qinyu XU Lixiao LU Yiqun Physical Oceanography Laboratory/Qingdao Collaborative Innovation Center of Marine Science and Technology Key Laboratory of Ocean-Atmosphere Interaction and Climate in Universities of ShandongOcean University of China

The present climate simulation and future projection of the Eastern Subtropical Mode Water （ESTMW） in the North Pacific are investigated based on the Geophysical Fluid Dynamics Laboratory Earth System Model （GFDL-ESM2M）. Spatial patterns of the mixed layer depth （MLD） in the eastern subtropical North Pacific and the ESTMW are well simulated using this model. Compared with historical simulation, the ESTMW is produced at lighter isopycnal surfaces and its total volume is decreased in the RCP8.5 runs, because the subduction rate of the ESTMW decreases by 0.82×10？6 m/s during February–March. In addition, it is found that the lateral induction decreasing is approximately four times more than the Ekman pumping, and thus it plays a dominant role in the decreased subduction rate associated with global warming. Moreover, the MLD during February–March is banded shoaling in response to global warming, extending northeastward from the east of the Hawaii Islands （20°N, 155°W） to the west coast of North America （30°N, 125°W）, with a max-imum shoaling of 50 m, and then leads to the lateral induction reduction. Meanwhile, the increased north-eastward surface warm current to the east of Hawaii helps strengthen of the local upper ocean stratification and induces the banded shoaling MLD under warmer climate. This new finding indicates that the ocean surface currents play an important role in the response of the MLD and the ESTMW to global warming.

关键词： eastern subtropical mode water global warming mixed layer depth subduction rate heat advection