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The Record-Breaking Extreme Drought in Yunnan Province, Southwest China during Spring-Early Summer of 2019 and Possible Causes

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Journal of Meteorological Research 2020年第5期34卷 997-1012页

作者： ting ding Hui GAO National Climate Center China Meteorological AdministrationBeijing 100081

In spring and early summer of 2019, Yunnan Province experienced the most severe seasonal drought on record,with days of extreme drought area exceeding 10^5 km^2 far more than normal. Consistently, the precipitation in each month from February to June is over 30% less than normal, and about 50% less in the most severe drought period(April–June). The rainy season in Southwest China(SWC) started on the third pentad in June 2019, which is the second latest in history. The rainy season in Yunnan started on 24 June, which is the latest(29 days later than normal). On the contrary, the onset of the South China Sea summer monsoon(SCSSM) is abnormally early. The lag time between the start of the rainy season in SWC and the onset of the SCSSM in 2019 is 7 pentads, which is the largest since 1961, much longer than the climate mean(less than 1 pentad). The present study analyzes the possible reasons why the rainy season came extremely late and the drought disaster persisted and intensified after a much early SCSSM, at both seasonal and subseasonal timescales. The abnormally late onset of the rainy season and the second greatest potential evapotranspiration(PET) since 1981 are the direct reasons for the persistent drought. Statistical results show that the water vapor from southwest of Yunnan in April–June contributes more than that from the east at the seasonal scale. In April–June 2019, however, the southern branch trough(SBT) was abnormally weak, the large and strong anticyclonic wind anomaly prevailed over the Bay of the Bengal(BOB), and the meridional water vapor transport to Yunnan was weak. At the subseasonal scale, the weaker SBT lasted the longest, and the strong convection over the BOB came up late despite of an early onset of the SCSSM, which resulted in reduced low-level moisture convergence in Yunnan and development of drought prior to the SCSSM onset. From the onset of SCSSM to the start of rainy season in SWC, the SBT and meridional water vapor transport from the B

关键词： Yunnan Province extreme drought South China Sea summer monsoon(SCSSM) rainy season in Southwest China(SWC) southern branch trough(SBT)

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An Efficient Algebraic Solution for Moving Source Localization from Quadruple Hybrid Measurements

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Chinese Journal of Electronics 2022年第2期31卷 255-265页

作者： ding ting ZHAO Yongsheng ZHAO Yongjun Henan High-Speed Railway Operation and Technological Research Center PLA Strategic Support Force Information Engineering University

This paper deals with the 3-D moving source localization using time difference of arrival(TDOA), frequency difference of arrival(FDOA), angle of arrival(AOA) and AOA rate measurements, gathered from a set of spatially distributed receivers. The TDOA,FDOA, AOA and AOA rate measurement equations were firstly established according to the space geometric relationship of the source relative to the receivers. Then an efficient closed-form algorithm for source position and velocity estimation from the quadruple hybrid measurements was proposed. The proposed algorithm converts the nonlinear measurement equations into a linear set of equations, which can then be used to estimate the source position and velocity applying weighted least square(WLS) minimization. In contrast to existing two-stage WLS algorithms, the proposed algorithm does not introduce any nuisance parameters and requires merely onestage, which enables for source localization with the fewest receivers necessary. Theoretical accuracy analysis shows that the proposed algorithm reaches the CramerRao lower bound, and simulation studies corroborate the efficiency and superiority of the proposed algorithm over other algorithms.

关键词： algebraic solution AOA rate measurement equations position measurement velocity estimation angle of arrival spatially distributed receivers Cramer-Rao lower bound source separation least squares approximations closed-form algorithm time difference of arrival two-stage WLS algorithms quadruple hybrid measurements time-of-arrival estimation source position weighted least square minimization frequency difference of arrival TDOA nonlinear measurement equations 3D moving source localization minimisation velocity measurement space geometric relationship direction-of-arrival estimation

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An unprecedented high temperature event in southern China in autumn 2021 and the essential role of the mid-latitude trough

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Advances in Climate Change Research 2022年第6期13卷 772-777页

作者： ting ding Xiang LI Hui GAO Climate Studies Key Laboratory National Climate CenterChina Meteorological AdministrationBeijing 100081China

Studies about high temperatures in China rarely touched the period beyond *** in September-early October 2021,a record-breaking high temperature event occurred in southern China,and affected agriculture in many *** the daily maximum temperature and the number of high temperature days were the highest in September since *** better understand the different features and possible causes of the extreme event in autumn from those in summer,the analysis of atmospheric circulation patterns was *** western Pacific subtropical high(WPSH)was quite stronger and extended much more westward in most of the days in September 2021 than its climatology,which directly caused this unprecedented autumn high temperature ***,the mid-latitude trough over the east of Japan may also play an essential role in this high temperature *** to the southward extension of the trough,a cyclonic circulation anomaly appeared at 850 hPa,and its northerly wind component prevailed in the west of the trough and blocked the eastward retreat of the *** a result,southern China was stably controlled by the WPSH,which led to the persistence of this high temperature *** conclusion is further confirmed by the statistical results from the analysis of the multi-year data and analogue *** to the previous studies,this study reveals the essential role of the mid-latitude trough and highlights the joint impacts of the WPSH and the trough in causing the unprecedented autumn high temperature event.

关键词： Extreme high temperature Western Pacific subtropical high Mid-latitude trough Southern China

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Abrupt Flood–Drought Alternation in Southern China during Summer 2019

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Journal of Meteorological Research 2021年第6期35卷 998-1011页

作者： Yuan YUAN Hui GAO ting ding National Climate Center China Meteorological AdministrationBeijing 100081

We investigated the abrupt alternation from flood to drought in southern China during summer 2019 using multiple *** anomalies of precipitation occurred in southern China in the summer of 2019 and the daily precipitation in the south of the middle and lower reaches of the Yangtze River valley showed an abrupt change from flood to drought conditions around *** highest precipitation in 39 yr was recorded between 1 June and 14 July *** circulation systems affecting this high precipitation included a persistent deepened East Asian trough,the southward location of the western Pacific subtropical high,an intensified East Asian subtropical jet,an anomalous low-level cyclone from southern Japan to southern China,and extremely strong positive vorticity over the Jiangnan *** different atmospheric circulation anomalies from 15 July to 31 August caused continuously high temperatures,below-normal precipitation,and severe drought in Jiangnan *** investigations showed that the sudden change in atmospheric circulation around mid-July started in the mid and lower troposphere and was influenced by the northward track of Tropical Cyclone Danas in the northwestern Pacific.

关键词： abrupt changes summer precipitation East Asian trough western Pacific subtropical high tropical cyclone

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Antibacterial Effect of Cinnamon Oil Combined with Thyme or Clove Oil

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Agricultural Sciences in China 2011年第9期10卷 1482-1487页

作者： LU Fei ding Yi-cheng YE Xing-qian ding Yu-ting College of Biological and Environmental Engineering Zhejiang University of Technology Hangzhou 310014 P.R.China Department of Food Science and Nutrition Zhejiang University Hangzhou 310029 P.R.China

Antibacterial effect of cinnamon oil combined with thyme or clove oil was studied in this paper. Agar dilution method was used to determine the minimum inhibitory concentrations （MICs） of the essential oils （EOs） of cinnamon, thyme, and clove oil against three Gram-positive bacteria （Bacillus subtilis, Bacillus cereus, and Staphylococcus aureus）, and two Gramnegative bacteria （Escherichia coli and Salmonella typhimurium）. The results showed that cinnamon was a promising antibacterial substance with MIC ranged from 0.1 to 0.4 μL mL^-1 for the five bacterial species. Agar dilution checkerboard method was used to test the combined antibacterial effect of cinnamon oil with thyme or clove oil. Combination of cinnamon and thyme oil showed an additive effect against all selected bacteria, and combination of cinnamon and clove oil displayed an additive effect against B. subtilis, B. cereus, S. aureus, and an indifferent effect against E. coli and S. typhimurium. Furthermore, gas chromatography-mass spectrometry （GC-MS） measurement was used to analyze the components of the EOs, and the main components of cinnamon, thyme, and clove were cinnamaldehyde, thymol, carvacrol and p-cymene, and eugenol, respectively.

关键词： cinnamon oil antibacterial effect essential oils combination chemical components

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2018: The Hottest Summer in China and Possible Causes

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Journal of Meteorological Research 2019年第4期33卷 577-592页

作者： ting ding Yuan YUAN Jianming ZHANG Hui GAO National Climate Center China Meteorological AdministrationBeijing 100081 Hunan Climate Center Changsha 410118

In 2018,China experienced the hottest summer since *** maximum,mean,and minimum temperatures all reached the *** temperatures in most regions were much higher than normal;in northern China especially,the temperature anomalies were above double of the standard *** variations of temperature anomalies appeared in the national mean and in northern China on different timescales from intraseasonal to annual,indicating that the above normal temperature in northern China contributed significantly to the record-breaking hot summer of entire *** among the high temperature in summer 2018,the tropospheric circulation,and the global sea surface temperatures(SSTs)are further *** is found that the intensified and more northward western Pacific subtropical high(WPSH),weakened Northeast China cold vortex(NECV),and positive geopotential height anomaly from northern China to the Sea of Japan resulted in the abnormally high temperature in summer *** late July to mid August,the WPSH was stronger than normal,with its ridge line jumping to north of 40°N;meanwhile,the NECV was much weaker and more northward than normal;both of the two systems led to the persistent high temperature in northern China during this *** addition,the SSTs in Kuroshio and its extension area(K–KE)in summer 2018 were also the highest since 1961 and the greatest positive SST anomaly in K–KE was favorable for the above normal geopotential height over North China–Northeast China–Japan at 500 hPa,giving rise to the exceptionally high temperature in northern China.

关键词： summer temperature western Pacific subtropical high(WPSH) Northeast China cold vortex(NECV) atmospheric circulation Kuroshio and its extension(K-KE)

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Comparison of surgical indications for hysterectomy by age and approach in 4653 Chinese women

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Frontiers of Medicine 2014年第4期8卷 464-470页

作者： Jingjing Jiang ting ding Aiyue Luo Yunping Lu ding Ma Shixuan Wang Department of Obstetrics and Gynecology Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan 430030 China

Approximately one million hysterectomies are performed each year in China. However, national data regarding the indications and the surgical approaches for hysterectomy are lacking. The aim of this study was to examine the surgical indications for hysterectomy in different age groups and the relative merits of different surgical approaches for hysterectomy in Chinese women. Clinical data from 4653 cases of hysterectomy performed in Tongji Hospital from 2004 to 2009 were analysed. Hysterectomy was most commonly performed among women aged 40-49 years （2299; 49.4%）. Overall, colporrhagia and abdominal pain were the two most common indications for hysterectomy. The most common indications by age groups were as follows： malignant ovarian tumour, 〈 20 years; malignant uterine tumour, 20-29 and 30-39 years; uterine myoma, 40-49 and 50-59 years; and uterine prolapse, 60-69 and 〉 70 years. The proportion of malignant aetiology also varied by age, being the highest in women aged 〈 20 years （75.0%） and the lowest in those aged 40-49 years （19.9%）. Approximately 35% women who had hysterectomies also had concomitant bilateral oophorectomy. The lowest rate of oophorectomy occurred in women aged 30-39years （15.8%）, whereas the highest rate was in those aged 50-59years （75.9%）. The abdominal surgical approach was used in 84% of all hysterectomies. Surgeries using the vaginal approach required a significantly shorter operating time （118 min average） than all other approaches （P 〈 0.05）. Both the amount of bleeding and the blood transfusion volume required were smaller in vaginal approaches, with no significant differences between the others. The surgical approaches used were also related to the scope of surgery. Both the surgical indications and the rates of bilateral oophorectomy varied by age. In terms of both operating time and the amount of bleeding and blood transfusion volume required, the vaginal approach was superior to all other surgical approaches.

关键词： hysterectomy surgical indications surgical approach bilateral oophorectomy

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Extreme cold wave in early November 2021 in China and the influences from the meridional pressure gradient over East Asia

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Advances in Climate Change Research 2022年第6期13卷 797-802页

作者： Xiang LI Ying-Juan ZHANG Hui GAO ting ding National Climate Center China Meteorological AdministrationBeijing 100081China Beijing Meteorological Service Beijing 100089China

In early November 2021,China experienced its second strongest cold wave event during *** the Siberian high is considered the main factor influencing cold wave events in East Asia,it was not extremely strong from 4 to November 9,*** spatial distribution of the correlation coefficients between the sea level pressure and the daily temperature anomalies shows a monopole pattern,with a notable negative centre in the southern part of the Siberian high monitoring ***,the correlation between the sea level pressure and temperature drop presents a typical dipole pattern,with a distinct negative centre in the northern monitoring domain and a positive centre in southern East *** the November 2021 super cold wave process,the sea level pressure anomalies display a dipole pattern with a higher centre in the north and a lower centre in the south owing to the northward shift of the Intertropical Convergence *** meridional pressure gradient index clearly reveals the non-negligible effect of subtropical low-pressure on this super cold wave process,indicating its possibly essential supplementary role in enhancing this *** above findings provide a new understanding of its mechanism and long-range forecasts.

关键词： Cold wave Siberian high Meridional pressure gradient Dipole pattern

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Extreme characteristics and causes of the drought event in the whole Yangtze River Basin in the midsummer of 2022

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Advances in Climate Change Research 2023年第5期14卷 642-650页

作者： Zhuo-Zhuo LYU Hui GAO Rong GAO ting ding Climate Studies Key Laboratory National Climate CenterChina Meteorological AdministrationBeijing 100081China Key Laboratory of Meteorological Disaster(KLME) Ministry of Education&Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)Nanjing University of Information Science&TechnologyNanjing 210044China

Due to their huge socio-economic impacts and complex formation causes,extreme and continuous drought events have become the focus and nodus of research in recent *** the midsummer(July-August)of 2022,a severe drought event occurred in the whole Yangtze River Basin(YRB),*** that period,the precipitation in the upper,middle and lower reaches of the YRB dropped over 40%less than the 1961-2021 climatic mean,which had never happened ***,the temperature was the highest during *** record-breaking magnitude of less rainfall and high temperature directly led to the continuous development of this extreme drought *** atmospheric moisture budget analysis revealed that the YRB midsummer rainfall anomaly was dominated by the anomalous powerful vertical moisture advection,which was derived from the strongest descending motion over the whole YRB in the 2022 midsummer during *** western Pacific subtropical high(WPSH)during the midsummer remained stronger,more westward and lasted longer than the climatic *** a result,the whole YRB was controlled by a positive geopotential height *** evidence revealed that the anomalous subtropical zonal flow played a crucial role in inducing the extreme descent over the ***,the anomalous upper-tropospheric easterly flow over the YRB in 2022 is the strongest during 1981-2022,modulating the generation of the unprecedented descent anomaly over the *** likelihood that an integrated connection of severe drought in East Asia and flood in West Asia and northwestern South Asia would increase when the extremely strong easterly anomalies in the upper troposphere emerged and induced descending adiabatic flow on the eastern sides of the Tibetan *** results of this study can provide scientific insights into the predictability of extreme drought events and provide ways to improve predictions.

关键词： Yangtze River Basin Midsummer extreme drought Atmospheric circulations Zonal flow Water vapour budget Subtropical high

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Linkage of the Decadal Variability of Extreme Summer Heat in North China with the IPOD since 1981

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Advances in Atmospheric Sciences 2023年第9期40卷 1617-1631页

作者： Tiejun XIE Ji WANG Taichen FENG ting ding Liang ZHAO Beijing Municipal Climate Center Beijing Meteorological BureauBeijing 100089China School of Atmospheric Sciences Sun Yat-sen UniversityZhuhai 528478China National Climate Center China Meteorological AdministrationBeijing 100081China State Key Laboratory of Numerical Modeling for Atmosphere Sciences and Geophysical Fluid Dynamics(LASG) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

Extreme summer heat can have serious socioeconomic impacts in North ***,we explore the decadal variability of the number of extreme heat days in early-to-mid summer(June and July)and a related potential mechanism consistent with the major seasonal occurrence period of extreme heat events in North China(NCSH).Observational analyses show significant decadal variability in NCSH for 1981–2021,potentially linked to the Indo-Pacific warm pool and Northwest Pacific Ocean dipole(IPOD)in early-to-mid *** diagnostic analysis and the linear baroclinic model(LBM)show that the positive IPOD in early-to-mid summer can excite upward vertical wind anomalies in the South China-East China Sea region,shifting the position of the western Pacific subtropical high(WPSH)to the east or weakening the degree of its control of the South China-East China Sea region,thus generating a positive geopotential height quadrupole(EAWPQ)pattern in the East Asia-Northwest Pacific ***,the EAWPQ can cause air compression(expansion)over North China by regulating the tropospheric thickness anomalies in North China,thus increasing(decreasing)***,an empirical model that incorporates the linear trend can better simulate the decadal NCSH compared to an empirical model based solely on the IPOD index,suggesting that the decadal variability of NCSH may be a combined contribution of the decadal IPOD and external linear forcing.

关键词： extreme heat early-mid summer North China Indo-Pacific warm pool and Northwest Pacific Ocean dipole(IPOD) decadal variability

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