Numerical calculation of the response of the south China sea to typhoon imbudo

The response of the South China Sea (SCS) to Typhoon Imbudo was examined using POM model. The results indicated that SST decreased by 2-6 degrees C with a rightward-biased response as Typhoon Imbudo passed across the SCS. Due to a strong mixing process, the mixed layer (ML) depth deepened as much as 10-60 m and ML heat budget lost 824.78 W/m(2), which was OF dominated by the vertical mixing. By the response of upper ML heat transport, the temperature below the ML increased and oscillated near the inertial period. Furthermore, strong inertial currents were generated by the storm with the max currents up to 1.4 m/s in the upper ML.

Application of altimetry data assimilation on mesoscale eddies simulation

Mesoscale eddy plays an important role in the ocean circulation. In order to improve the simulation accuracy of the mesoscale eddies, a three-dimensional variation (3DVAR) data assimilation system called Ocean Variational Analysis System (OVALS) is coupled with a POM model to simulate the mesoscale eddies in the Northwest Pacific Ocean. In this system, the sea surface height anomaly (SSHA) data by satellite altimeters are assimilated and translated into pseudo temperature and salinity (T-S) profile data. Then, these profile data are taken as observation data to be assimilated again and produce the three-dimensional analysis T-S field. According to the characteristics of mesoscale eddy, the most appropriate assimilation parameters are set up and testified in this system. A ten years mesoscale eddies simulation and comparison experiment is made, which includes two schemes: assimilation and non-assimilation. The results of comparison between two schemes and the observation show that the simulation accuracy of the assimilation scheme is much better than that of non-assimilation, which verified that the altimetry data assimilation method can improve the simulation accuracy of the mesoscale dramatically and indicates that it is possible to use this system on the forecast of mesoscale eddies in the future.

Numerical simulation of tides and tidal currents in Liaodong Bay with POM

A three-dimensional ocean circulation model, called Princeton Ocean Model (POM), is employed to simulate tides and tidal currents in Liaodong Bay. The nested grid technique is adopted to improve the computation precision. Computed harmonic constants of M-1, M-2 tides at five tidal gauge stations and surface elevations at two oil platforms are compared with those observed, and show good agreements with them. Based on the calculated results, the co-amplitude and co-phase tag lines of nil and M-2 tidal constituents, the residual current field of M-2 constituent, tidal form, tidal Current ellipse and the moving style of tidal current are given. It is found that diurnal tidal constituents have no amphidromic point whereas semi-diurnal constituents have one in the region of interest. Meanwhile, some meaningful results are concluded and presented, which are conducive to a thorough knowledge of the characteristics of tides and tidal currents in the Liaodong Bay.

长期施肥对黑土POM分布及其碳水化合物特性的影响

本文以吉林省公主岭“国家黑土肥力与肥料效益长期定位监测基地”的黑土为材料，研究长期施肥对黑土POM的分布及POM（FPOM和OPOM）中碳水化合物特性的影响，结果表明： 有机肥及有机肥与化肥配施显著提高了土壤中碳水化合物的含量，促进了植物来源的中性糖和真菌来源的氨基糖在土壤中的积累。在有机质含量较高的黑土上长期施用高量有机肥会出现养分过剩的现象。不同施肥处理下黑土有机质中中性糖的相对含量与不施肥相比无显著变化，氨基糖的相对含量则显著增加。随着有机肥施用量的增加，土壤中中性糖的含量也随之显著增加，而氨基糖则没有明显变化。 有机肥及有机肥与化肥配施能显著增加黑土中POM以及POM-C、POM-N和碳水化合物的含量，且均随有机肥施用量的增加而增加。各个处理中OPOM的碳、氮和碳水化合物含量远远高于FPOM。POM中各个单糖对施肥的响应与碳水化合物的总量基本一致。单施高量有机肥及有机肥与化肥配施均能显著提高POM中中性糖和氨基糖占有机质的比例，单施低量有机肥对POM中氨基糖和FPOM中中性糖占有机质的比例作用不明显，而能显著增加OPOM中中性糖占SOM的比例。在POM的中性糖中葡萄糖和木糖对SOM的贡献较大，氨基糖中氨基葡萄糖的贡献较大。OPOM中碳水化合物对SOM的贡献大于FPOM。FPOM中中性糖主要来源于植物，而OPOM中则主要来源于植物和微生物。在短期范围内，施肥并没有引起POM中两种来源氨基糖比例的显著变化，而从长期来看，有机肥处理却使POM中细菌源氨基糖的积累得到了加强。单施化肥对黑土有机质和黑土POM的含量以及二者中的碳、氮和碳水化合物的含量和组成均没有显著的影响。

An integrated air-POM syngas/dimethyl ether process from natural gas

A Cu-Zn-Al methanol catalyst combined with HZSM-5 was used for dimethyl ether (DME) synthesis from a syngas containing nitrogen, which was produced by air-partial oxidation of methane (air-POM). Air-POM occurred at 850 degreesC, 0.8 MPa, CH4/air/H2O/CO2 ratio of 1/2.4/0.8/0.4 over a Ni-based catalyst modified by magnesia and lanthanum oxide with 96% CH4 conversion and constantly gave syngas with a H-2/CO ratio of 2/1 during a period of 450 h. The obtained N-2-containing syngas was used directly for DME synthesis. About 90% CO per-pass conversion, 78% DME selectivity and 70% DME yield could be achieved during 450 h stability testing under the pressure of 5.0 MPa. the temperature of 240 degreesC and the space velocity of 1000 h(-1). (C) 2002 Elsevier Science B. V. All rights reserved.

Stable isotope variations in particulate organic matter and a planktivorous fish in the Yangtze River

Temporal and spatial changes in delta(13) C and delta 15 N of particulate organic matter (POM) and Hemiculter leucisculus were studied in the Yangtze River of China. Isotopic signatures of POM showed seasonal variations, which was assumed to be associated with allochthonous organic input and autochthonous phytoplankton growth. delta C-13 of H. leucisculus was 1.1 % higher than that of POM, which suggested that the food source of H. leucisculus was mostly from the POM. A mass balance model indicated the trophic position of H. leucisculus in the food web of Yangtze River was estimated to be 2.0 - 2.1, indicating that this fish mainly feeds on planktonic organic matter, which agreed with previous gut content analysis.

LIQUID-CRYSTALLINE POLYSURFACTANT

A new kind of amphiphilic polymer(PAMC(16)B) has been synthesized where the amphiphilic moiety is attached as a side chain via the hydrophilic end to the polymer backbone. DSC, POM, and WAXD study revealed that the polysurfactant formed thermotropic liquid crystalline phase. The liquid crystalline domains appeared after annealed at the melt for a period of time, and evolved with annealing. It was indicated that the thermodynamic effect played a significant role on the self-aggregation of hydrophobic ends, so as to form liquid crystalline structure. X-ray investigation suggested that the mesophase structure could be described as smectic with lamellar type of packing, in which alkyl tails aggregated to form layer, A model of supermolecular structure was given.

THE EFFECTS OF MONSOONS AND CONNECTIVITY OF SOUTH CHINA SEA ON THE SEASONAL VARIATIONS OF WATER EXCHANGE IN THE LUZON STRAIT

Seasonal variations of water exchange in the Luzon Strait are studied numerically using the improved Princeton Ocean Model (POM) with a consideration of the effects of connectivity of South China Sea (SCS) and monsoons. The numerical simulations are carried out with the strategy of variable grids, coarse grids for the Pacific basin and fine grids for the SCS. It. is shown that the Mindoro Strait plays an important role in adjusting the water balance between the Pacific and the SCS. The SCS monsoon in summer seasons hinders the entrance of the Pacific water into the SCS through the Luzon Strait while the SCS monsoon in winter seasons promotes the entrance of Pacific water into the SCS through the Luzon Strait. However, the SCS monsoon does not affect the annual mean Luzon Strait transport, as is mainly determined by the Pacific basin wind.

Simulation of barotropic and baroclinic tides in the South China Sea

The four leading tidal constituents M-2, S-2, K-1 and O-1 in the South China Sea are simulated by using POM. The model is forced with tide-generating potential and four leading tidal constituents at the open boundary. In order to simulate more exactly, TOPEX/Poseidon altimeter data are assimilated into the model and the open boundary is optimized. The computed co-tidal charts for M-2 and K-1 constituents are generally consistent with previous results in this region. The numerical simulation shows that energetic internal tides are generated over the bottom topography such as the Dongsha Islands, the Xisha Islands, the Zhongsha Islands, the Nansba Islands and the Luzon Strait.

Tidally induced upwelling off Yangtze River estuary and in Zhejiang coastal waters in summer

MASNUM wave-tide-circulation coupled numerical model (MASNUM coupled model, hereinafter) is developed based on the Princeton Ocean Model (POM). Both POM and MASNUM coupled model are applied in the numerical simulation of the upwelling off Yangtze River estuary and in Zhejiang coastal waters in summer. The upwelling mechanisms are analyzed from the viewpoint of tide, and a new mechanism is proposed. The study suggests that the tidally inducing mechanism of the upwelling includes two dynamic aspects: the barotropic and the baroclinic process. On the one hand, the residual currents induced by barotropic tides converge near the seabed, and upwelling is generated to maintain mass conservation. The climbing of the residual currents along the sea bottom slope also contributes to the upwelling. On the other hand, tidal mixing plays a very important role in inducing the upwelling in the baroclinic sea circumstances. Strong tidal mixing leads to conspicuous front in the coastal waters. The considerable horizontal density gradient across the front elicits a secondary circulation clinging to the tidal front, and the upwelling branch appears near the frontal zone. Numerical experiments are designed to determine the importance of tide in inducing the upwelling. The results indicate that tide is a key and dominant inducement of the upwelling. Experiments also show that coupling calculation of the four main tidal constituents(M-2, S-2, K-1, and O-1), rather than dealing with the single M-2 constituent, improves the modeling precision of the barotropic tide-induced upwelling.

卫星高度计资料在海洋潮汐研究中的应用

本文依据收集到的392个地面验潮站8个主要分潮（M2、S2、K1、O1、N2、K2、P1及Q1）的调和常数，对现有7个全球大洋潮汐模式的准确度进行了检验，结果显示各模式在深海区域均达到了比较高的准确度，相互之间差别也不大。经验模式GOT00和CSR4.0、同化模式NAO99、反演同化模式TPXO7.0、数值同化模式FES2002和FES2004的M2分潮均方根偏差在3 cm左右，其它分潮（S2、K1、O1、N2、K2、P1及Q1）大约在1～2 cm。本文还依据中国近海18个岛屿的调和常数对其中的5个大洋潮汐模式的准确度进行了检验，结果表明，M2分潮均方根偏差在6～14 cm，明显高于大洋部分的偏差，其中日本国家天文台的潮汐模式NAO99在中国近海的结果相对较准确。 我们利用1992年8月至2008年8月的TOPEX/POSEIDON和JASON-1(T/P-J)卫星高度计资料，对沿卫星轨道的302816个站点进行了14个分潮的潮汐调和分析，得到了全球大洋潮汐的8个主要分潮以及2个气象分潮Sa、Ssa的经验同潮图。主要结果有：（1）各分潮在卫星上升轨道与下降轨道的交叉点(约7000个)相关性分析表明：M2分潮的振幅和迟角的相关系数很高（分别为0.9965和0.9961）；S2，K1，O1和Sa分潮也有较好的相关性（相关系数为0.94～0.99）；（2）该结果与392地面个验潮站吻合较好，其中M2分潮的振幅、迟角和向量的均方根偏差分别为：1.73 cm，2.340和2.93 cm；S2，K1和O1分潮的振幅、迟角和向量的均方根偏差为1 cm左右，5.250～7.270和1.5～2.1 cm，该精度与最近几年国际上的主要大洋潮汐模式的准确度相近；（3）首次通过卫星资料获得了Sa、Ssa分潮的同潮图。周期为1年的Sa分潮与大洋105个地面站相比，振幅、迟角和向量的均方根偏差分别为1.50 cm、18.360和2.16 cm。在此基础上，进一步分析了构成Sa、Ssa气象分潮的两个主要因素（海水密度以及海面气压）在全球的分布。 在T/P-J等卫星资料无法覆盖到南大洋和北冰洋，本文利用Princeton Ocean Model（POM）进行了数值模拟，模拟结果与162个地面实测站（其中南大洋30个，北冰洋132个）的观测比较一致。基于卫星资料分析的结果和数值模拟结果合并得到了全球大洋的8个主要分潮同潮图。在此基础上通过全球潮汐能量耗散的计算得到潮能通量的分布，并得到全球M2、S2、K1和O1分潮的潮汐能量耗散率为2.431TW、0.401TW、0.336TW和0.176TW。 本文还利用卫星资料对南海潮汐进行了研究，在中国南海，获得了主要的半日潮、全日潮、四分日分潮和长周期分潮（M2，S2，N2，K2，K1，O1，P1，Q1，M4, MS4，Sa, Ssa）的经验同潮图。与南海沿岸94个地面验潮站的数据符合得比较好，M2，S2，K1及O1等4个主要分潮的平均振幅差为2～4 cm，均方根偏差分别是9～11 cm.其它4个主要分潮N2，K2，P1，Q1的平均振幅差为1～2 cm，均方根偏差为2～4 cm。此外，本文还利用卫星高度计资料潮汐分析结果沿卫星轨道进行高通滤波，分离得出中国近海的M2，S2，K1及O1分潮的内潮信息。

天津近岸台风暴潮漫滩数值模拟研究

中国是太平洋沿岸国家中频繁遭受风暴潮灾害的国家之一，提高风暴潮预报的准确性，可以直接减少海洋灾害造成的经济损失和人员伤亡，具有十分积极的重要意义。针对天津近岸海域的地形和易受风暴潮漫滩灾害侵袭的特点，本文基于对POM( Princeton Ocean Model)模式的改进，建立了天津近岸海域三维动边界风暴潮漫滩模型，并选择典型天气个例，对天津近岸区域台风影响下的风暴潮漫滩进行了数值模拟研究。 本文的计算建立在POM模式基础上，采用两重网格嵌套的方法，第一套网格对整个渤海海域进行固定边界风暴潮的数值模拟，第二套网格对天津近岸海域进行可变边界模拟。通过两套网格的合理衔接，大区域网格尽量覆盖风场范围，小区域网格细致刻画浅水区域，提高了风暴潮的模拟分辨率。 第二套网格的计算，采用干湿网格法，在POM模式中加入干湿点的判断，而岸界条件与固定边界模式一样，从而提高了模式的模拟精度，能够较真实地模拟出台风作用下风暴潮水位随岸线的移动。本文采用的Flather-Heaps干湿网格法，简单易行，不会增加程序的复杂度和计算量。 模式选取7203、8509、9216、9711号台风计算风暴潮漫滩水位变化，通过与塘沽站点实测数据的比较，计算增水曲线过程与实测结果吻合较好，基本能够真实反映天津近岸的风暴潮水位变化情况及漫滩范围。本文的研究结果验证了改进POM模式为动边界数值模型并应用于浅海区域的可行性。