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Based on the daily precipitation data from national meteorological stations, ERA5 reanalysis data and the CMA Tropical Cyclone Best Track Dataset during 1979-2019, this paper sets out to conduct statistical analysis and synoptic classification of 51 large-scale persistent severe rainfall (LPSR) events during the rainy season in Guangxi Autonomous Region, and study the key circulation characteristics and differences in frontogenetic structure. The main conclusions are as follows: There are six synoptic types of the LPSR events, namely North China Trough (NCT), South Branch Trough (SBT), Low Vortex&Shear (LVS), Subtropical High Edge (SHE), Tropical Cyclone (TC) and Monsoon Depression (MD), all of which are characterized by a background of stable synoptic circulation. The NCT has the highest frequency, and the SBT has the longest average duration and the widest average influence range. The precipitation intensity of NCT, SBT and LVS is almost the same, and their precipitation areas overlap in northeast Guangxi. The frontogenesis is caused by the special terrain of this area and its interaction with cold and warm air. The initial height of strong frontogenesis is higher and shallow. There are some intrusions of dry and cold air in the middle and low layers, especially in the NCT, and such intrusions increase atmospheric instability and induce frontogenesis development. Moreover, SBT is accompanied by warm rain belt along the coast. The precipitation intensity of SHE, TC and MD is more intense, and their main precipitation area is in southern Guangxi. In these cases, the frontogenesis is mostly caused by the warm air lifted by the terrain, the narrow tube effect, and the friction convergence, which triggers and maintains efficient warm cloud precipitation. The initial height of strong frontogenesis of the latter two are lower and deeper, and their efficiency of warm cloud precipitation is higher, while the strong frontogenesis of the SBT's coastal frontogenesis area and SHE are relatively shallower. [ABSTRACT FROM AUTHOR]

Copyright of Evaluation & Analysis of Drug-Use in Hospitals of China is the property of Evaluation & Analysis of Drug-Use in Hospitals of China Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Scientiarum Naturalium Universitatis Sunyatseni / Zhongshan Daxue Xuebao is the property of Sun-Yat-Sen University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To further understand the basic characteristics of the tropical cyclones over the South China Sea (SCSTC), this paper uses the best track dataset of tropical cyclones compiled by the Shanghai Typhoon Institute of China Meteorological Administration (CMA-ATI) to analyze the frequency, origin and intensity changes of SCSTC with different moving paths from 1949 to 2019 by wavelet analysis and synthetic analysis. The results show that: (1) The frequency of SCSTC shows a decreasing trend year by year. The overall frequency of SCSTC in the northeast direction is relatively low, and the peak months are mainly in May and June. The overall frequency of SCSTC in the west/ northwest direction is relatively high, accounting for about 76 % of the total, and the peak months are mainly in August and September. The change in the frequency of SCSTC in the west/ northwest direction is consistent with the movement of the ridgeline of the western Pacific subtropical high. When the ridgeline of the subtropical high gradually moves north (south), the frequency of SCSTC gradually increases (decreases). (2) The average intensity of the SCSTC in the northeast direction is stronger than that in the west/ northwest direction, and the life cycle is longer. Secondary strengthening of typhoons and strong typhoons is more significant in northeastward SCSTC. (3) The oirigin points of SCSTC with different paths have undergone northward uplift and then southward withdrawal with the change of seasons, which is consistent with the movement of subtropical high ridgeline. The oirigin point of SCSTC in the northeast direction is 2～3 latitudes norther than that of SCSTC in the west/ northwest direction. [ABSTRACT FROM AUTHOR]

Based on the Global Ensemble Forecast System data, the present study uses the WRF model and the GEFS dynamic downscaling method to obtain the regional ensemble forecast initial states. Moreover, the assimilated analysis field is integrated to achieve the reginal ensemble forecast for a precipitation event during annually first rainy season in South China. Four tests, namely Hybrid, 3DVar, EnKF, and Ctrl, are carried out for a torrential rain process on June 10, 2019 in South China. We also explore the evolution characteristics of the ensemble disturbance and ensemble spread for the assimilation schemes with difference background error covariance matrices and evaluate the precipitation simulation performance of different tests. The results show that: (1) Hybrid can improve the initial field of the model, while 3DVar and EnKF failed. (2) For wind, temperature, and relative humidity, the forecast error of Hybrid in the early forecast is less than that of 3DVar and EnKF. In the middle and late forecast, the forecast error of 3DVar and EnKF is reduced and is smaller than that of Hybrid. As for the ensemble disturbance energy, Hybrid and Ctrl are better than 3DVar and EnKF in the early forecast, and 3DVar and EnKF are better than Hybrid and Ctrl in the middle and late forecasts. (3) According to the 24-hour cumulative precipitation scores, the assimilation test is better than Ctrl, 3DVar and EnKF are better than Hybrid; 3DVar scores the best in heavy and moderate rainfall and EnKF scores the best in torrential rain and above. (4) For 24-hour cumulative precipitation ensemble statistical analysis, the area under the curve value of the assimilation test is greater than that of Ctrl; 3DVar performs the best in the 10mm~100mm cumulative precipitation threshold and EnKF performs the best in the 125mm cumulative precipitation threshold. [ABSTRACT FROM AUTHOR]

Copyright of Acta Scientiarum Naturalium Universitatis Sunyatseni / Zhongshan Daxue Xuebao is the property of Sun-Yat-Sen University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Sciencepaper is the property of China Sciencepaper and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Shandong Medical Journal is the property of Shandong Medical Health Newspapers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Kunming Medical University / Kunming Yike Daxue Xuebao is the property of Kunming Medical Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)