Previous studies have often used the 500 hPa geopotential height to define indices of the western Pacific subtropical high (WPSH). However, some studies reported that global warming caused a significant increase in geopotential height, particularly at the middle and lower latitudes, leading artificial results about long-term trend of the WPSH. To avoid the spurious signals resulting from global warming, this study first redefines the area, intensity, westward ridge point and ridge line indices of the WPSH by adopting the stream function R of horizontal circulation in the three-pattern decomposition of global atmospheric circulation (3P-DGAC). Subsequently, the climatic characteristics of the WPSH in summer are investigated by applying the new indices based on four reanalysis datasets. The results show that the circulation features of the WPSH could be revealed by the stream function R in 3P-DGAC. Moreover, the rain belt over East Asia is located at the northwest periphery of the zero-value isoline of the stream function R. We conclude that the climatological average WPSH is contracted and retreated eastward during 1979–2018 relative to 1948–1978. Nevertheless, by analyzing interdecadal changes of the time series of the new indices during 1948–2018, we find that area and intensity indices decrease with time before the end of 1970s and increase slightly with time after the end of 1970s, the western ridge point index moves eastward with time before the end of the 1970s and moves westward slightly with time after the end of 1970s, as well as there is no obvious interdecadal variations in the ridge line index. Because of the evident dynamical meaning, the stream function R in 3P-DGAC can be used as an objective indicator to describe the interdecadal variation of the WPSH under global warming.
This paper describes a rapid procedure for diagnosis of penaeid viral disease using the immune serological method. The SPA
(Staphylococcal Protein A) coagglutination test in early diagnosis of penaeid viral disease has yielded satisfactory results.
This is the first time SPA is used in China for diagnoses of viral diseases of marine invertebrates, especially penaeid shrimp.
The SPA early diagnostic method is characterized by accuracy, rapidity, simplicity and convenience, low cost, high specificity,
strong sensitivity and micro-detectability, and easy dissemination and adaptability in prawn farms. 相似文献
基于气象信息综合分析处理系统第4版(Meteorology Information Comprehensive Analysis Process System4,MICAPS 4)的精细化天气预报平台的设计与应用。从我国精细化气象格点预报业务需求出发,介绍了精细化预报系统的总体组织结构和数据流程,基于MVVM模式的总体架构设计、功能设计以及实现。平台采用高性能的分布式内存对象缓存技术,提高了系统运行效率;采用模型视图分离,将数据逻辑与用户界面剥离,增强其可扩展性,更便于省级本地化应用;开发了要素场协调性处理功能,集成了降水、温度等客观预报算法,并提供丰富的主/客观交互工具。目前,该平台已在业务中应用,为全国精细化预报业务提供了重要支撑。 相似文献
Devastating tornadoes in China have received growing attention in recent years, but little is known about their formation, structure, and evolution on the tornadic scale. Most of these tornadoes develop within the East Asian monsoon regime, in an environment quite different from tornadoes in the U.S. In this study, we used an idealized, highresolution (25-m grid spacing) numerical simulation to investigate the deadly EF4 (Enhanced Fujita scale category 4) tornado that occurred on 23 June 2016 and claimed 99 lives in Yancheng, Jiangsu Province. A tornadic supercell developed in the simulation that had striking similarities to radar observations. The violent tornado in Funing County was reproduced, exceeding EF4 (74 m s–1), consistent with the on-site damage survey. It was accompanied by a funnel cloud that extended to the surface, and exhibited a double-helix vorticity structure. The signal of tornado genesis was found first at the cloud base in the pressure perturbation field, and then developed both upward and downward in terms of maximum vertical velocity overlapping with the intense vertical vorticity centers. The tornado’s demise was found to accompany strong downdrafts overlapping with the intense vorticity centers. One of the interesting findings of this work is that a violent surface vortex was able to be generated and maintained, even though the simulation employed a free-slip lower boundary condition. The success of this simulation, despite using an idealized numerical approach, provides a means to investigate more historical tornadoes in China. 相似文献
