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201.
202.
Evidence has been found for the teleconnection of Indian Ocean Dipole mode (IOD) events in the southern high latitude sea
surface pressure field, although the mechanisms that might lead to such far-reaching links remain unresolved. Based on the
teleconnection pattern between IOD and the climate anomaly in the upper troposphere, we propose one such mechanism here: the
energy propagation theory of the atmospheric planetary wave. Ray traces of the atmospheric planetary waves suggest that the
energy propagation of the waves could be responsible for the teleconnection between IOD and tropospheric climate anomalies
in southern high latitudes. 相似文献
203.
在2—D不变性矩快速计算的基础上,利用人工神经网络,使用不变性矩完成2—D形状的识别。实验结果与现有文献的结果比较,本文采用的方法具有特征数目少、意义统一、识别快速、准确的特点。 相似文献
204.
Bispectrumandasymmetryofwaveshape¥DingPingxing;KongYazhen;andSunFu(StateKeyLaboratoryOfEstuarineand ̄alR ̄h,InstituteofEStuarin... 相似文献
205.
岬间砂质海岸平衡形态模型及其在华南海岸的应用 总被引:1,自引:0,他引:1
本文介绍了对数螺线、双曲线、抛物线三种岬间海湾平面平衡形态模型,并通过对比分析,表明抛物线为三种模型中较为理想的模型.根据抛物线模型的基本原理,本文提供了模型的可行性操作,并就抛物线模型对华南岬间海湾的应用展开了讨论. 相似文献
206.
Long-Term Variability of North Pacific Subtropical Mode Water in Response to Spin-Up of the Subtropical Gyre 总被引:1,自引:0,他引:1
The Meteorological Research Institute's ocean general circulation model (MRI-OGCM) has been used to investigate the temperature
variability of the North Pacific Subtropical Mode Water (NPSTMW) over a time series longer than 5 years via the spin-up of
the subtropical gyre. Besides an interannual variation, the wintertime sea surface temperature in the area where the NPSTMW
is formed, and the temperature of the NPSTMW itself, both change remarkably in a >5-year time scale. An analysis of heat budgets
showed that the long-term changes in NPSTMW temperature are due mainly to a leading advection of heat by the Kuroshio Extension
and compensating surface heat flux. As a result of a dynamical adjustment to the wind stress fields, the transports of the
Kuroshio and the Kuroshio Extension increased in the mid 1970s with a lag of 3 years after the wind stress curl in the central
North Pacific. The increased heat advection by the Kuroshio Extension induces a warming in the mixed layer in the NPSTMW formation
area, followed by a warming of the NPSTMW itself. Both these warming actions increase the heat release to the atmosphere.
These results imply that the surface heat flux over the Kuroshio Extension area varies in response to the change in the ocean
circulation through the spin-up of the subtropical gyre.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
207.
Chang Ao Wenzhi Zeng Peiling Yang Weimin Xing Guoqing Lei Jingwei Wu Jiesheng Huang 《水文研究》2021,35(4):e14130
Natural hillslopes are mostly composed of complex slope shapes, which significantly affect soil erosion. However, existing studies have mainly focused on uniform slopes to simplify complex hillslopes, and the mechanisms responsible for the influence of slope shape on soil and nutrient losses are still not well understood, especially in the application of soil improvers to reduce soil loss. To investigate the effects of slope shape and polyacrylamide (PAM) application on runoff, soil erosion and nutrient loss, this study conducted artificial field rainfall experiments involving two PAM application rates and nine slope shapes. The results indicate that the average amount of soil loss from convex slopes was 1.5 and 1.3 times greater than that from concave and uniform slopes, respectively, and the average amount of ammonia nitrogen loss and phosphate loss increased by 24.0%–58.6%. Soil and nutrient losses increased as the convexity of the convex slopes increased. For runoff, there was little difference between concave and convex slopes, but the runoff amount for both slopes was greater than that for uniform slopes. After PAM application, the soil loss decreased by more than 90%, and the nutrient loss decreased by 28.2%–68.1%. The application of PAM was most effective in reducing soil erosion and nutrient loss from convex slopes, and it is recommended to appropriately increase the PAM application rate for convex slopes. A strong linear relationship between ammonia nitrogen and phosphate concentrations and sediment concentrations was found in the runoff on slopes with no PAM application. However, this linear relationship weakened for slopes with PAM application. The findings of this study may be valuable for optimizing nonpoint source pollution management in basins. 相似文献
208.
Abstract This study investigates the characteristics of hydrograph components from a watershed in Taiwan. Hydrograph components were modelled by using a model of three serial reservoirs with one parallel reservoir. Mean rainfall was calculated by using the block kriging method. The model parameters for 38 events were calibrated by using the shuffled complex evolution optimization algorithm. The model verification was made using 18 events. Based on the study results, the following findings were obtained: (1) for single-peak events, times to peak of hydrograph components are an increasing power function of the peak time of rainfall; (2) peak discharges of hydrograph components are linearly proportional to that of total runoff, and the ratios of quick and slow runoff are approximately 83% and 17% of total runoff, respectively; and (3) the total volume of quick runoff component is 52% of total runoff and that of slow runoff is 27%. Editor D. Koutsoyiannis Citation Li, Y.-J., Cheng, S.-J. Pao, T.-L. and Bi, Y.-J., 2012. Relating hydrograph components to rainfall and streamflow: a case study from northern Taiwan. Hydrological Sciences Journal, 57 (5), 861–877. 相似文献
209.
In this paper, the parametric tropical cyclone models for storm surge modeling are further developed. Instead of tangential wind speed via cyclostrophic balance and radial wind speed using a simple formulation of defection angle, the analytical expressions of tangential and radial wind speed distribution are derived from the governing momentum equations based on the general symmetric pressure distribution of Holland and Fujita. The radius of the maximum wind is estimated by tropical cyclone wind structure which is characterized by the radial extent of special wind speed. The shape parameter in the pressure model is estimated by the data of several tropical cyclones that occurred in the East China Sea. Finally, the Fred cyclone (typhoon 199417) is calculated, and comparisons of the measured and calculated air pressures and wind speed are presented. 相似文献
210.