热带印度洋偶极子发生和演变机制的数值研究

对中国科学院大气物理研究所(IAP)大气科学和地球流体力学数值模拟国家重点实验室(LASG)发展的第三代海洋模式(L30T63 OGCM)进行了改进。分析了该模式1959年1月—1998年12月的40a积分结果，以此研究热带印度洋偶极子发生、发展和消亡的物理机制。对数值模拟结果的分析表明，赤道印度洋表面异常东风引起的异常环流结构是偶极子发生、发展的主要动力学原因，其表面异常东风转换为异常西风所引起的异常环流结构调整是偶极子消亡的主要动力学原因；海气界面热通量异常的交换对热带印度洋海表温度距平偶极子模态的形成和演变起着重要的作用；垂直输送作用是热带印度洋次表层海温偶极子模态发生和演变的主要物理机制。     

Aliasing due to sampling of the Adriatic temperature, salinity and density in space

High-resolution underway temperature and conductivity measurements collected by R/V Knorr during winter and spring 2003 are used to characterize errors associated with spatial aliasing in the northern and central Adriatic Sea. During winter, 99th percentile temperature, salinity and density errors were 0.62 °C, 0.25 and 0.12 kg/m³ (0.25 °C, 0.10 and 0.05 kg/m³) for sampling at 10 km (5 km) horizontal resolution, respectively. The corresponding values in spring were 1.31 °C, 0.50 and 0.40 kg/m³ (0.93 °C, 0.25 and 0.22 kg/m³) for the 10 km (5 km) sample spacing, respectively. The largest errors were associated with energetic regions over the shallow, western Adriatic, in front of the Po River mouth and off the tip of the Istrian peninsula. The deeper eastern basin exhibited smaller errors. The variability of errors in time and space reflected the variability of small-scale density features, characterized by wavelengths as small as 2 km in winter and 1 km in spring and being more pronounced in the western and northern parts of the Adriatic. As these results indicate that errors associated with undersampling can be considerable, they should be taken into account while planning future CTD measurements in the region.     

一种基于BP算法学习的小波神经网络

为发展 Szu的基于信号表示的小波神经网络 ,提出一种多输入多输出的小波网络模型 ,网络隐层采用框架小波函数、输出层采用 Sigmoid激励函数 ,并选用“熵误差函数”以加速网络的学习速度。奇偶判别和混沌时间序列预测例子的实验结果表明了它具有良好的函数逼近能力和推广能力 ,收敛速度和均方误差均优于相同结构的多层感知器模型。     

梭鱼仔鱼耳石日轮形成及自然种群日龄的鉴定

梭鱼实验种群样本,系于1987年5月,从山东大沽河口搜集的亲鱼经人工授精后孵出的仔鱼在实验室培育取得;自然种群样本,于同年同地区采集。对于实验种群耳石生长轮形成的周期性进行了研究。结果表明,实验种群培育天数(D)与耳石生长轮数(N)之间的关系以回归式N=D-1.89表达之;根据实验种群耳石轮纹形成的周期性规律,鉴定了自然种群的日龄,表明二者具相似的周期性规律;协方差分析表明,梭鱼早期阶段的生长,自然种群比实验种群快。     

黄海、渤海底层温度数值预报方法的研究

根据文献［ｌ］建立的底层温度（ＴＨ）与其水柱垂向平均温度（）的经验关系，结合流体动力学方程和（垂向平均）热传导方程，发展了以水气温差和风速为已知量的底层温度二维数值预报模式。该模式避开了海面热量和动量输入在垂直水柱中分配的复杂物理过程而直接报出底层水温场，具有较好的实用性；此外，从试报结果看，效果令人满意。     

A Numerical Model of Coastal Processes of Sand Beaches Based on Long-Term Wave Series

A numerical model of shoreline change of sand beaches based on long-term field wave data is proposed, the explicit and implicit finite difference forms of the model are described, and an application of the model is presented. Results of the application indicate that the model is sensitive to the order of the input wave data, and that the effects of long-term wave series and the effects of the mean annual wave conditions on the model are different. Instead of a single wave condition, the wave series will make the calibration and the verification of the model more practical and the results of the model more reasonable.     

Oxygen Uptake During Repeated Exposure to Temperature Change: Physiological Divergence in Panamanian Cognate Pairs and Latitudinally Distant Populations of Decapod Crustacea

Abstract. The emergence of the Isthmus of Panama subdivided the amphi-American biota. In the present study, Pacific and Atlantic populations of four cognate pairs of crabs were used to discern whether exposure to different thermal regimes in habitats, in the putative absence of gene flow, has resulted in physiological divergence. Populations that potentially form a common genetic pool were also used; these were populations of the Atlantic Panama cognate that occur in Belize and Florida. Decreases in water temperature occur periodically in Pacific Panama and Florida, but not in Atlantic Panama or Belize. In this study, physiological divergence in oxygen uptake was assessed in response to repeated exposure to either control and decreased temperature or control and increased temperature. Results indicate that, in only some of the genera tested, exposure to decreases in habitat temperature has resulted in divergence. Partial support is found for the corollary that adaptation to an environment with periods of decreased temperature results in reduced compensation during exposure to elevated temperature.     

Subsurface Water Masses in the Central North Pacific Transition Region: The Repeat Section along the 18° Meridian

A repeat hydrographic section has been maintained over two decades along the 180° meridian across the subarctic-subtropical transition region. The section is naturally divided into at least three distinct zones. In the Subarctic Zone north of 46°N, the permanent halocline dominates the density stratification, supporting a subsurface temperature minimum (STM). The Subarctic Frontal Zone (SFZ) between 42°–46°N is the region where the subarctic halocline outcrops. To the south is the Subtropical Zone, where the permanent thermocline dominates the density stratification, containing a pycnostad of North Pacific Central Mode Water (CMW). The STM water colder than 4°C in the Subarctic Zone is originated in the winter mixed layer of the Bering Sea. The temporal variation of its core temperature lags 12–16 months behind the variations of both the winter sea surface temperature (SST) and the summer STM temperature in the Bering Sea, suggesting that the thermal anomalies imposed on the STM water by wintertime air-sea interaction in the Bering Sea spread over the western subarctic gyre, reaching the 180° meridian within a year or so. The CMW in this section originates in the winter mixed layer near the northern edge of the Subtropical Zone between 160°E and 180°. The CMW properties changed abruptly from 1988 to 1989; its temperature and salinity increased and its potential density decreased. It is argued that these changes were caused by the climate regime shift in 1988/1989 characterized by weakening of the Aleutian Low and the westerlies and increase in the SST in the subarctic-subtropical transition region. This revised version was published online in August 2006 with corrections to the Cover Date.     

A map series of the Southern East Pacific Rise and its flanks, 15° S to 19° S

Four large-scale bathymetric maps of the Southern East Pacific Rise and its flanks between 15° S and 19° S display many of the unique features of this superfast spreading environment including abundant seamounts (the Rano Rahi Field), axial discontinuities, discontinuity migration, and abyssal hill variation. Along with a summary of the regional geology, these maps will provide a valuable reference for other sea-going programs on-and off-axis in this area, including the Mantle ELectromagnetic and Tomography (MELT) experiment.