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Precipitation seesaw phenomenon and its formation mechanism in the eastern and western parts of Northwest China during the flood season

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Science China Earth Sciences 2019年第12期62卷 2083-2098页

作者： Qiang ZHANG Jingjing LIN Weicheng LIU Lanying HAN Institute of Arid Meteorology China Meteorological AdministrationKey Laboratory of Arid Climatic Change and Reducing Disaster of Gansu ProvinceKey Open Laboratory of Arid Climatic Change and Disaster Reduction of CMALanzhou 730020China Gansu Provincial meteorological Bureau Lanzhou 730020China lanzhou regional Climate Center Lanzhou 730020China lanzhou Central meteorological Observatory Lanzhou 730020China

Extending across three major plateaus,namely the Qinghai-Tibetan Plateau,the Inner Mongolia-Xinjiang Plateau and the Loess Plateau,Northwest China has the complex terrain and spatio-temporal climate variations,and is affected by the interactions among different circulation systems,such as the summer monsoon,the westerlies and the plateau *** understanding of the climate variability,as well as its characteristics and evolution mechanisms in this area has been limited so *** this paper,the precipitation characteristics and mechanisms in the eastern and western parts of Northwest China during the flood season are compared and analyzed based on the data from 192 national meteorological observational sites in Northwest China in *** results show that,divided by the northern boundary of the East Asian summer monsoon,there are huge differences in the precipitation variation characteristics between the eastern and western *** inter-annual variations,interdecadal variations and total trends in the two parts all show a significant seesaw ***,it is found that the seesaw phenomenon of precipitation variation is closely related to the opposite variation between the East Asian summer monsoon index(MI)and the westerly circulation index(WI).In addition,the inverse variations on different time scales are only related to the contributions of precipitation at specific ***,in the two matching patterns of precipitation in the seesaw phenomenon,the middle and high latitudes are occupied by the"high-low-high"wave trains in the precipitation increases in the east of Northwest China(ENWC)and decreases in the west of Northwest China(WNWC)pattern,meaning precipitation increases in ENWC and decreases in *** the opposite"low-high-low"wave trains at 500 hPa height are observed in the middle and high latitudes in the WH-EA pattern at 500 hPa height,meaning precipitation increases in WNWC and decreases in ***,the atmosphere circul

关键词： Northwest China Precipitation changes Seesaw phenomenon Summer monsoon system Westerly circulation system South Asian High

Research on Water-Vapor Distribution in the Air over Qilian Mountains

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Acta meteorologica Sinica 2008年第1期22卷 107-118页

作者：张强张杰孙国武狄潇泓 Key Laboratory of Arid Climatic Changing and Reducing Disaster of Gansu Province Key Opening Laboratory of Arid Climatic Change and Disaster Reduction of CMA Institute of Arid Meteorology China meteorological Administration lanzhou regional meteorological centre

Based on the remote sensing data, the radiosonde data and precipitation data observed by weather stations, distributions of atmospheric water-vapor and cloud motion wind over the Qilian Mountains are analyzed. Moreover, on the basis of water-vapor and cloud motion wind analyses, relations of atmospheric water-vapor distribution with precipitation~ atmospheric circulation, and terrain are investigated. The results show that distributions of atmospheric water-vapor and precipitation in the Qilian Mountains are affected by the westerly belt, the southerly monsoon （the South Asian monsoon and plateau monsoon）, and the East Asian monsoon. In the northwest Qilian Mountains, water-vapor and precipitation are entirely affected by the westerly belt, and there is no other direction water-vapor transport except westerly watervapor flux, hence, the northwest region is regarded as the westerly belt region. In the south and middle of the mountaili, water-vapor is mainly controlled by the southerly monsoon, 37.7% of the total watervapor is from the south, especially in summer, the southerly water-vapor flux accounts for 55.9% of the total, and furthermore the water-vapor content in the southerly flow is more than that in the westerly flow. The southerly monsoon water-vapor is influenced by the South Asian monsoon from the Indian Ocean and the plateau monsoon in the Qinghai-Tibetan Plateau, thus, the south and middle region is called southerly monsoon region. But in the northeast Qilian Mountains, the East Asian monsoon is the main climate system affecting the water-vapor. Besides west and northwest water-vapor fluxes, there are a lot of easterly water-vapor fluxes in summer. The frequency of easterly cloud motion winds in summer half year accounts for 27.1% of the total, though the frequency is not high, it is the main water-vapor source of summer precipitation in this region, therefore, the northwest region is a marginal region of the East Asian monsoon. On the other hand, atmosp

关键词： satellite remote sensing data Qilian Mountains atmospheric water-vapor, cloud-motion wind, atmospheric circulation

Application of Direct Assimilation of ATOVS Microwave Radiances to Typhoon Track Prediction

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Advances in Atmospheric Sciences 2004年第2期21卷 283-290页

作者：张华薛纪善朱国富庄世宇吴雪宝张风英 Atmospheric Science Department Lanzhou University Lanzhou 730000 Chinese Academy of Meteorological Sciences China Meteorological Adminstration Beijing 100081 Chinese Academy of meteorological Sciences China Meteorological Adminstration Beijing 100081 National Satellite meteorological Center China Meteorological Adminstration Beijing 100081

In order to solve the difficult problem of typhoon track prediction due to the sparsity of conventional data over the tropical ocean, in this paper, the No. 0205 typhoon Rammasun of 4-6 July 2002 is studied and an experiment of the typhoon track prediction is made with the direct use of the Advanced TIROS-N Operational Vertical Sounder (ATOVS) microwave radiance data in three-dimensional variational data assimilation. The prediction result shows that the experiment with the ATOVS microwave radiance data can not only successfully predict the observed fact that typhoon Rammasun moves northward and turns right, but can also simulate the action of the fast movement of the typhoon, which cannot be simulated with only conventional radiosonde data. The skill of the typhoon track prediction with the ATOVS microwave radiance data is much better than that without the ATOVS data. The typhoon track prediction of the former scheme is consistent in time and in location with the observation. The direct assimilation of ATOVS microwave radiance data is an available way to solve the problem of the sparse observation data over the tropical ocean, and has great potential in being applied to typhoon track prediction.

关键词： radiance direct assimilation typhoon track prediction

Analysis of a Convective Storm Crossing Poyang Lake in China

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Journal of meteorological Research 2020年第3期34卷 529-545页

作者： Haibo ZOU Shuwen ZHANG Yanan LIU Weidong ZHANG Xixi YANG College of Atmosphere Sciences Lanzhou UniversityLanzhou 730000 Institute of meteorological Sciences of Jiangxi Province Jiangxi Meteorological BureauNanchang 330046

A convective storm crossing Poyang Lake(PL)in China during 1200-1600 UTC on 13 May 2015 is *** results show that this storm occurs ahead of a 500-hPa trough with weak low-level temperature advection and a convectively stable layer between 925 and 850 hPa,and the tail of the storm is enhanced when its spearhead sweeps over PL after the *** to the heating and moistening of PL,the convectively stable layer over PL is destabilized;and instead,a deep(below 700 hPa)convectively unstable layer is ***,both the radiative cooling and the storm-induced cooling result in a rapid air(near-surface)and land temperature decrease in the surrounding ***,a large lake-land temperature difference(about 6℃)occurs,which is conducive to generating land-lake breeze and enhancing the convergence of the low-level ***,the PL-induced deep convectively unstable layer and the enhanced low-level convergence jointly strengthen the crossing *** further confirm this,two simulations(with or without PL)are conducted with the Weather Research and Forecast(WRF)*** simulation with PL successfully reproduces the evolution of the storm crossing PL,while the simulation without PL *** the simulation with PL,a highμse tongue at 850 hPa associated with the storm moves eastward and downward,and merges with the PL-induced lake boundary layer,forming a deep convectively unstable layer under 700 ***,in the simulation without PL,the stable layer constantly maintains under 900 *** addition,the 900-hPa wind difference between the simulations with and without PL shows a land-lake breeze circulation that strengths the convergence of the low-level wind.

关键词： Poyang Lake(PL) lake-enhanced precipitation lake–land breeze convective instability

Tropospheric NO_2 vertical column densities retrieved from ground-based MAX-DOAS measurements at Shangdianzi regional atmospheric background station in China

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Journal of Environmental Sciences 2019年第6期31卷 186-196页

作者： Siyang Cheng Jianzhong Ma Weiping Cheng Peng Yan Huaigang Zhou Liyan Zhou Peng Yang State Key Laboratory of Severe Weather & CMA Key Laboratory of Atmospheric Chemistry Chinese Academy of Meteorological Sciences China Waterborne Transport Research Institute CMA meteorological Observation centre Shangdianzi regional Air Background Station Beijing Meteorological Bureau meteorological Bureau of Shijiazhuang

Ground-basedMulti-AXis Differential Optical Absorption Spectroscopy(MAX-DOAS)measurements were performed at Shangdianzi(SDZ)regional atmospheric background station in northern China from March 2009 to February *** tropospheric NO_2vertical column densities(VCDs)were retrieved to investigate the background condition of the Beijing–Tianjin–Hebei developed economic circle in *** seasonal variation of mean NO_2tropospheric VCDs(VCD_(Trop))at SDZ is apparent,with the maximum(1.3×10^(16)molec/cm^2)in February and the minimum(3.5×10^(15)molec/cm^2)in August,much lower than those observed at the Beijing city *** average daytime diurnal variations of NO_2VCD_(Trop )are rather consistent for all four seasons,presenting the minimum at noon and the higher values in the morning and *** largest and lowest amplitudes of NO_2VCD_(Trop)diurnal variation appear in winter and in summer,*** diurnal pattern at SDZ station is similar to those at other less polluted stations,but distinct from the ones at the urban or polluted *** NO_2VCDs at SDZ are strongly dependent on the wind,with the higher values being associated with the pollution plumes from Beijing *** NO_2VCDs derived from ground-based MAX-DOAS at SDZ show to be well correlated with corresponding OMI(Ozone Monitoring Instrument)satellite products with a correlation coefficient R=***,the OMI observations are on average higher than MAX-DOAS NO_2VCDs by a factor of 28%,probably due to the OMI grid cell partly covering the south of SDZ which is influenced more by the pollution plumes from the urban areas.

关键词： Ground-basedMAX-DOAS Tropospheric NO2 Satellite validation Pollution plume regional atmospheric background station

RETROSPECTIVE TIME INTEGRAL SCHEME AND ITS APPLICATIONS TO THE ADVECTION EQUATION

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Acta Mechanica Sinica 2002年第1期18卷 53-65页

作者：封国林董文杰杨培才曹鸿兴丑纪范 Department of meteorological Sciences Lanzhou University Lanzhou China 730000 Mathematics and Physics College Yangzhou University Yangzhou China 225009 Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China 100029 Chinese Academy of meteorological Sciences Beijing China 100081 Department of meteorological Sciences Lanzhou University Lanzhou China 730000

To put more information into a difference scheme of a differential equation for making an accurate prediction, a new kind of time integration scheme, known as the retrospective (RT) scheme, is proposed on the basis of the memorial dynamics. Stability criteria of the scheme for an advection equation in certain conditions are derived mathematically. The computations for the advection equation have been conducted with its RT scheme. It is shown that the accuracy of the scheme is much higher than that of the leapfrog (LF) difference scheme.

关键词： time integration memorization numerical weather prediction difference scheme advection equation

SEASONAL VARIATION OF RAIN-BELTS OVER CHINA

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Advances in Atmospheric Sciences 1985年第3期2卷 368-375页

作者：徐国昌李梅芳张志银 lanzhou lanzhou meteorological Center

Decadal rainfall data of 228 stations in 1951-1970 and upper-wind records in 1960-1969 published by the Central meteorological Bureau and relevant provincial organizations are employed in the analysis. It is found that the characteristic features of seasonal variation of the main rain-belts over eastern China to the east of 105°F are quite different from those to the west, over the Qinghai-Xi?hang (Tibetan) Plateau. The eastern rain-belts are closely related to the low level flow convergence lines and significantly influenced by the south Asian high and the western Pacific subtropical high.

关键词： over SEASONAL VARIATION OF RAIN-BELTS OVER CHINA

Objective identification research on cold vortex and mid-summer rainy periods in Northeast China

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Chinese Physics B 2015年第4期24卷 571-580页

作者：龚志强封泰晨房一禾 Laboratory for Climate Studies and Climate Monitoring and Diagnose National Climate Center China Meteorological Administration Atmosphere and Science College Lanzhou University regional Climate Center of Shenyang

Considering the differences between the Northeast China Cold Vortex （CV） and the Mid-Summer （MS） rainy period and their corresponding atmospheric circulations are comprehensively analyzed, and the objective identification methods of defining the annual beginning and ending dates of Northeast China CV and MS rainy periods are developed respectively. The annual beginning date of the CV （MS） rainy period is as follows. In a period from April to August, if daily regional mean precipitation ryi is larger than yearly regional mean precipitation R （or 2R） on a certain day, the station precipitation rs is larger than the station yearly mean precipitation （r/ （or 2（r）） in at least 50% of stations in Northeast China, and this condition is satisfied in the following 2 （7） days, then this date is defined as the beginning date of the CV （MS） rainy period. While the definition of the ending date of the MS rainy period shows the opposite process to its beginning date. With this objective identification method, the multi-year average （1981-2010） beginning date of the CV rainy period is May 3, the beginning date of the MS rainy period is June 27, the ending day of the CV rainy period is defined as the day before the beginning date of the MS rainy period, and the ending date of the MS rainy period is August 29. Meanwhile, corresponding anomaly analysis at a 500-hPa geopotential height, 850-hPa wind, Omega and relative humidity fields all show that the definitions of the average beginning and ending dates of the CV and MS rainy periods have a certain circulation meaning. Furthermore, the daily evolution of the CV index, meridional and zonal wind index, etc. all show that these objectively defined beginning and ending dates of the CV and MS rainy periods have climate significance.

关键词： Northeast China cold vortex rainy period mid-summer rain period objective identification method

Observed levels and trends of gaseous SO_2 and HNO_3 at ***,China:Results from 1997 to 2009

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Journal of Environmental Sciences 2013年第4期25卷 726-734页

作者： Weili Lin Xiaobin Xu Xiaolan Yu Xiaochun Zhang Jianqing Huang centre for Atmosphere Watch and Services Meteorological Observation CentreChina Meteorological Administration Key Laboratory for Atmospheric Chemistry Chinese Academy of Meteorological Sciences Waliguan Observatory

Long-term measurements of SO2 and HNO3, particularly those from the background sites, are rarely reported. We present for the first time the long-term measurements of SO2 and HNO3 at Waliguan （WLG）, the only global baseline station in the back-land of the Eurasian Continent. The concentrations of SO2 and HNO3 were observed at WLG from 1997 to 2009. The observed annual mean concentrations of SO2 and HNO3 at WLG were 1.28 ± 0.41 and 0.22 ± 0.19 μg/m3, respectively. The HNO3 concentrations were much higher in warmer seasons than in colder seasons, while the SO2 concentrations showed a nearly reversed seasonal pattern. In most months, the concentration of HNO3 was significantly correlated with that of SO2, suggesting that some common factors influence the variations of both gases and the precursors of HNO3 may partially be from the SO2-emitting sources. The SO2 concentration had a very significant （P 〈 0.0001） decreasing trend （-0.2 μg/（***）） in 1997-2002, but a significant （P 〈 0.05） increasing trend （＋0.06 μg/（m3-yr）） in 2003-2009. The HNO3 concentration showed no statistically significant trend during 1997-2009. While the decrease of SO2 in 1997-2002 agrees with the trend of global SO2 emissions, the increase in 2003-2009 is not consistent with the decreasing trends in many other regions over the world. Trajectory analysis suggests that the airmasses from the northern Qinghai-Tibetan Plateau and the Takla Makan Desert regions contributed significantly to the increasing trends of SO2 and HNO3 at WLG in 2003-2009, with a rate of ＋0.13 μg/（***） and ＋0.007μg/（***）, respectively.

关键词： SO2 HNO3 long-term trends Waliguan global baseline