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Temporal variability of vertical heat flux in the Makarov Basin during the ice camp observation in summer 2010

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Acta Oceanologica Sinica 2015年第11期34卷 118-125页

作者： GUO Guijun SHI Jiuxin JIAO Yutian college of physical and environmental oceanography Ocean University of China Key laboratory of physical oceanography Ministry of Education

Based on hydrographic data obtained at an ice camp deployed in the Makarov Basin by the 4th Chinese Arctic Research Expedition in August of 2010, temporal variability of vertical heat flux in the upper ocean of the Makarov Basin is investigated together with its impacts on sea ice melt and evolution of heat content in the remnant of winter mixed layer （rWML）. The upper ocean of the Makarov Basin under sea ice is vertically stratified. Oceanic heat flux from mixed layer （ML） to ice evolves in three stages as a response to air temperature changes, fluctuating from 12.4 W/m2 to the maximum 43.6 W/m2. The heat transferred upward from ML can support （0.7＋0.3） cm/d ice melt rate on average, and daily variability of melt rate agrees well with the observed results. Downward heat flux from ML across the base of ML is much less, only 0.87 W/m2, due to enhanced stratification in the seasonal halocline under ML caused by sea ice melt, indicating that increasing solar heat entering summer ML is mainly used to melt sea ice, with a small proportion transferred downward and stored in the rWML. Heat flux from ML into rWML changes in two phases caused by abrupt air cooling with a day lag. Meanwhile, upward heat flux from Atlantic water （AW） across the base of rWML, even though obstructed by the cold halocline layer （CHL）, reaches 0.18 W/m2 on average with no obvious changing pattern and is also trapped by the rWML. Upward heat flux from deep AW is higher than generally supposed value near 0, as the existence of rWML enlarges the temperature gradient between surface water and CHL. Acting as a reservoir of heat transferred from both ML and AW, the increasing heat content of rWML can delay the onset of sea ice freezing.

关键词： sea ice heat flux remnant of winter mixed layer heat content Makarov Basin

Seasonal Variations of Several Main Water Masses in the Southern Yellow Sea and East China Sea in 2011

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Journal of Ocean University of China 2013年第4期12卷 524-536页

作者： QUAN Qi MAO Xinyan YANG Xiaodan HU Yingying ZHANG Haiyan JIANG Wensheng Key laboratory of physical oceanography MOE college of physical and environmental oceanography Ocean University of China

The seasonal variations of several main water masses in the southern Yellow Sea (SYS) and East China Sea (ECS) in 2011 were analyzed using the in-situ data collected on four *** was something special in the observations for the Yellow Sea Warm Current (YSWC) ,the Yellow Sea Cold Water Mass (YSCWM) and the Changjiang Diluted Water (CDW) during that *** YSWC was confirmed to be a seasonal current and its source was closely associated with the Kuroshio onshore intrusion and the northerly *** was also found that the YSCWM in the summer of 2011 occupied a more extensive area in comparison with the climatologically-mean case due to the abnormally powerful wind prevailing in the winter of 2010 and decaying gradually *** from the reduced Changjiang River discharge,the CDW spreading toward the Cheju Island in the summer of 2011 was weaker than the long-term mean and was confined to flow southward in the other *** other water masses seemed normal without noticeable anomalies in *** Yellow Sea Coastal Current (YSCC) water,driven by the northerly wind,flowed southeastward as a whole except for its northeastward surface layer in *** Taiwan Warm Current (TWC) was the strongest in summer and the weakest in winter in its northward *** Kuroshio water with an enhanced onshore intrusion in autumn was stable in hydrographic features apart from the seasonal variation of its surface layer.

关键词： water masses seasonal variations southern Yellow Sea East China Sea

Effects of high-order nonlinearity and rotation on the fission of internal solitary waves in the South China Sea

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Journal of Hydrodynamics 2013年第2期25卷 226-235页

作者：张善武范植松 college of physical and environmental oceanography Ocean University of China

A variable coefficient, rotation-modified extended Kortweg-deVries （vReKdV） model is applied to the study of the South China Sea （SCS）, with focus on the effects of the high-order （cubic） nonlinearity and the rotation on the disintegration process of large-amplitude （170 m） Internal Solitary Waves （ISWs） and the semi-diurnal internal tide propagating from the deep basin station to the slope and shelf regions in a continuously stratified system. The numerical solutions show that the high-order nonlinearity significantly affects the wave profile by increasing the wave amplitude and the phase speed in the simulated area. It is shown that the initial KdV-type ISW will decay faster when the rotation dispersion is considered, however the wave profile does not change significantly and the rotation effect is not important. The simulations of the semi-diurnal internal tide indicate that the phase of the wave profile is shifted earlier when the rotation effect is included. A solitary wave packet emerges on the shelf, and the wave speed is also greater when considering the rotation dispersion. In addition, the effects of the background currents are discussed further in this paper It is found that the background currents generally change the magnitude and occasionally change the sign of the nonlinear coefficients in the northern SCS.

关键词： Internal Solitary Waves (ISWs) internal tide high-order nonlinearity rotation

Wave Characteristics and Extreme Parameters in the Bohai Sea

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China Ocean Engineering 2012年第2期26卷 341-350页

作者：王智峰吴克俭周良明吴伦宇 college of physical and environmental oceanography Ocean University of China physical oceanography laboratory Ocean University of China The First Institute of oceanography State Oceanic Administration

This paper is aimed at the whole Bohai Sea, as the complement and improvement of wave characteristics and extreme parameters. Wave fields were simulated in the Bohai Sea by using wave model SWAN from 1985 to 2004. The input data based on the hindcast of high-resolution wind fields from RAMS and water level fields from POM, which have been tested and verified well. Comparisons of significant wave heights between simulation and station observations show a good agreement in general. By statistical analysis, the wave characteristics such as significant wave heights, dominant wave directions and their seasonal variations are discussed. In addition, main wave extreme parameters and directional extreme values particularly for 100-year return period are investigated.

关键词： Bohai Sea wave fields statistical characteristics extreme parameters

A Numerical Study of Tidal Asymmetry: Preferable Asymmetry of Nonlinear Mechanisms in Xiangshan Bay, East China Sea

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Journal of Ocean University of China 2014年第5期13卷 733-741页

作者： XU Peng MAO Xinyan JIANG Wensheng ZHOU Liangming physical oceanography laboratory Ocean University of China college of physical and environmental oceanography Ocean University of China

In-situ measurements in Xiangshan Bay, the East China Sea, show that the duration of the rising tide is shorter than that of the falling tide around the bay mouth, while it becomes much longer in the inner bay. A finite volume coastal ocean model(FVCOM) with an unstructured mesh was applied to simulate the asymmetric tidal field of Xiangshan Bay. The model reproduced the observed tidal elevations and currents successfully. Several numerical experiments were conducted to clarify the roles of primary mechanisms underlying the asymmetric tidal field. According to the model results, the time-varying channel depth and nonlinear advection prefer shorter duration of the rising tide in Xiangshan Bay, while the time-varying bay width favors longer duration of the rising tide. The overtides generated by these two opposite types of nonlinear mechanisms are out of phase, resulting in smaller M4 amplitude than the sumfold of each individual contribution. Although the bottom friction as a nonlinear mechanism contributes little to the generation of overtide M4, it is regarded as a mechanism that could cause a shorter duration of the rising tide, for it can slow down the M2 phase speed much more than it slows down the M4 phase speed. The time-varying depth, nonlinear advection and bottom friction are dominating factors around the bay mouth, while the time-varying width dominates in the inner bay, causing the tidal elevation asymmetry to be inverted along the bay.

关键词： FVCOM tidal asymmetry Xiangshan Bay nonlinear mechanisms

Mechanistic insight into the synergy between nickel single atoms and nanoparticles on N-doped carbon for electroreduction of CO2

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Journal of Energy Chemistry 2025年第1期100卷 327-336页

作者： Mingdong Sun Wenwen Guan Cailing Chen Chao Wu Xiaoling Liu Biao Meng Tao Chen Yu Han Jun Wang Shibo Xi Yu Zhou State Key laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Nanjing Tech University Advanced Membranes and Porous Materials Center Physical Sciences and Engineering Division King Abdullah University of Science and Technology Institute of Sustainability for Chemicals Energy and Environment A*STAR (Agency for Science Technology and Research) college of Materials Science and Engineering Sichuan University

The synergy of single atoms （SAs） and nanoparticles （NPs） has demonstrated great potential in promoting the electrocatalytic carbon dioxide reduction reaction （CO2RR）;however,the rationalization of the SAs/NPs proportion remains one challenge for the catalyst ***,a Ni2+-loaded porous poly（ionic liquids）(PIL) precursor synthesized through the free radical self-polymerization of the ionic liquid monomer,1-allyl-3-vinylimidazolium chloride,was pyrolyzed to prepare the Ni,N co-doped carbon materials,in which the proportion of Ni SAs and NPs could be facilely modulated by controlling the annealing *** catalyst Ni-NC-1000 with a moderate proportion of Ni SAs and NPs exhibited high efficiency in the electrocatalytic conversion of CO2into *** Ni K-edge X-ray absorption near-edge structure （XANES） spectra and theoretical calculations were conducted to gain insight into the synergy of Ni SAs and *** charge transfer from Ni NPs to the surrounding carbon layer and then to the Ni SAs resulted in the electron-enriched Ni SAs active *** the electroreduction of CO2,the coexistence of Ni SAs and NPs strengthened the CO2activation and the affinity towards the key intermediate of*COOH,lowering the free energy for the potential-determining*CO2→*COOH step,and therefore promoted the catalysis efficiency.

关键词： Activation energy

Sea-level variation/change and thermal contribution in the Bering Sea

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Acta Oceanologica Sinica 2005年第6期24卷 36-45页

作者： ZUO Juncheng ZHANG Jianli DU Ling LI Peiliang LI Lei college of physical and environmental oceanography Ocean University of China Qingdao 266003 China College of Physical and Environmental Oceanography Ocean University of China Qingdao 266003 China College of Physical and Environmental Oceanography Ocean University of China Qingdao 266003 China College of Physical and Environmental Oceanography Ocean University of China Qingdao 266003 China College of Physical and Environmental Oceanography Ocean University of China Qingdao 266003 China

The long-term sea-level trend in the Bering Sea is obtained by the analysisof TOPEX/Poseidon altimeter data, including the data of two tide gauges. The averaged sea-level inthe Bering Sea rises at a rate of 2.47 mm/a from 1992 to 2002. The mean sea-level is falling in themost part of the Bering Sea, especially in its central basin, and it is rising in the northeasternpart of the Bering Sea. During the 1998/99 change, the sea-level anomaly differences exhibit asignificant sea-level anomaly fall in the deep basin of the Bering Sea, which is roughly in the sameposition where a prominent SST fall exists. The maximal fall of sea-level is about 10 cm in thesouthwestern part of the Bering Sea, and the maximal fall of about 2℃ in the SST also appeared inthe same region as the sea level did. The steric sea-level change due to temperature variations isdiscussed. The results are compared with the TOPEX/Poseidon altimeter data at the different spatialscales. It is indicated that the seasonal amplitude of the steric height is about 35% of theobserved TOPEX/Poseidon amplitude, which is much smaller than the 83% in the mid-latitudes area. Thesystematic difference between the TOPEX/Poseidon data with the range of about 7.5 cm and thethermal contribution with the range of about 2.5 cm is about 5 cm. This indicates that the thermaleffect on the sea level is not as important as the case in the mid-latitudes area. In the BeringSea, the phase of the steric height leads the observed sea level by about three months.

关键词： sea-level variation steric bering sea

Climatology and seasonal variability of the Mindanao Undercurrent based on OFES data

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Acta Oceanologica Sinica 2013年第7期32卷 14-20页

作者： WANG Caixia LAN Jian WANG Gang college of physical and Environment oceanography Ocean University of China physical oceanography laboratory Ocean University of China

The simulation of an ocean general circulation model for the earth simulator （OFES） is transformed to an isopycnal coordinate to investigate the spatial structure and seasonal variability of the Mindanao Under- current （MUC）. The results show that （1） potential density surfaces, δ0=26.5 and δ0=27.5, can be chosen to encompass the M UC layer. Southern Pacilic tropical water （SPTW）, Antarctic Intermediate Water （AAIW） and high potential density water （HPDW） constitute the MUC. （2） Climatologically, the MOC exists in the form of dual-core. In some months, the dual-core structure changes to a single-core structure. （3） Choosing section at 8°N for calculating the transport of the MUC transport is reliable. Potential density constraint provides a good method for calculating the transport of the MOC. （4） The annual mean transport of the MUC is 8.34 × 106 m3/s and varies considerably with seasons： stronger in late spring and weaker in winter.

关键词： Mindanao Undercurrent southern Pacilic tropical water Antarctic intermediate water

On the Blocking Flow Patterns in the Euro–Atlantic Sector:A Simple Model Study

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Advances in Atmospheric Sciences 2014年第5期31卷 1181-1196页

作者： LUO Dehai YAO Yao physical oceanography laboratory College of Physical and Environmental OceanographyOcean University of China Key laboratory of Regional Climate-Environment for East Asia Chinese Academy of Science

The flow patterns of Euro-Atlantic blocking events in winter are investigated by dividing the sector into three sub- regions： 60°-30°W （Greenland region）; 20°W-30°E [eastern Atlantic-Europe （EAE） region]; and 50°-90°E （Ural region）. It is shown that blocking events in winter are extremely frequent in the three sub-regions. Composite 500-mb geopotential height fields for intense and long-lived blocking events demonstrate that the blocking fields over Greenland and Ural regions exhibit southwest-northeast （SW-NE） and southeast-northwest （SE-NW） oriented dipole-type patterns, respectively, while the composite field over the EAE region exhibits an Ω-type pattern. The type of composite blocking pattern seems to be related to the position of the blocking region relative to the positive center of the climatological stationary wave （CSW） anomaly existing near 10°W. The physical cause of why there are different composite blocking types in the three sub-regions is identified using a nonlinear multiscale interaction model. It is found that when the blocking event is in almost the same position as the positive CSW anomaly, the planetary-scale field can exhibit an Ω-type pattern due to the enhanced positive CSW anomaly. Neverthe- less, a SW-NE （SE-NW） oriented dipole-type block can occur due to the reduced positive CSW anomaly as it is farther in the west （east） of the positive CSW anomaly. The total fields of blocking in the three regions may exhibit a meandering flow comprised of several isolated anticyclonic and cyclonic vortices, which resembles the Berggren-Bolin-Rossby meandering jet type.

关键词： blocking flow pattern synoptic eddies nonlinear multiscale interaction climatological stationary wave anomaly