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30 April 2016, Volume 32 Issue 2 Previous Issue    Next Issue

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Effect of different cloud microphysical parameterization schemes of WRF model on autumn precipitation over West China AI Kai, ZHENG Yi-qun, ZENG Xin-min, CHEN Hao-wei 2016, 32 (2):  1-10.  doi: 10.11927/j.issn.1673-503X.2016.02.001 Abstract ( 330 )   PDF (3463KB) ( 582 )   Save In this paper, an autumn precipitation event on September 13 to 20, 2011 over the West China was simulated using the WRF model with five different cloud microphysical parameterization schemes.The simulated results were compared and possible reasons of precipitation changes among different experiments were analyzed.The results show that every scheme can be used in the simulation of the autumn rainfall in the West China, and each of them can well generate night rain.However, the falling area of simulated rainfall and its intensity are underestimated by the Kessler cloud microphysical parameterization scheme, Simulated precipitation intensity is stronger when using the Lin scheme.In general, the main precipitation processes are simulated better with the Ferrier and WSM3 schemes.By comparing simulation results of five different cloud microphysical parameterization schemes, it is found that the precipitation intensities simulated by five schemes are of good association with the upward motion strength simulated by the WRF model. References | Related Articles | Metrics

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Analysis of forming reason of freezing rain weather and its characteristics in mountain and plain of Anhui province JIANG Yang, HE Zhi-xin, ZHOU Kun, ZHU Hong-fang, WANG Dong-yong 2016, 32 (2):  11-17.  doi: 10.11927/j.issn.1673-503X.2016.02.002 Abstract ( 343 )   PDF (4440KB) ( 523 )   Save In order to investigate the causes of winter freezing weather and improve freezing rain forecasting accuracy, synoptic characteristics of a freezing event in February of 2010 in Anhui province were analyzed based on conventional observation data, intensive observation data and the NCEP reanalysis data.At the same time, numerical simulation by a WRF model for this process was performed, and physical field and stratification condition were discussed.The results show that freezing rain in the south mountain area and north plain area of Anhui province is mainly caused by strong cold air moving down south quickly, which makes cold continental high meeting the western Pacific subtropical high and forming a saddle shape pressure field.Analysis of simulation suggests that forming reasons and stratification features of this process in the mountain and plain differ significantly.Forming of freezing rain in the mountain area is related to block and lifting of mountain to cold and warm air, while it needs strong cold air moving southward rapidly in the plain area and produces stratification structure that is favorable to generate freezing rain weather.In the mountain area, it has great temperature inversion gradient and higher cold center height when freezing rain weather occurs.In the plain, it has great negative temperature center and higher cold center height near the surface when freezing rain weather occurs, while there is not stable corresponding relation with temperature inversion gradient.Generation of freezing rain weather is a complex physics process, and it has relationship with intensity of temperature inversion, height of cold pad and amplitude of temperature change. References | Related Articles | Metrics

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Diagnostic analysis of a strong precipitation in Liaoning province LIU Jing, REN Chuan, DONG Wei, CAI Kui-zhi, CUI Sheng-quan, WANG Ying, CHEN Ni-na 2016, 32 (2):  18-27.  doi: 10.11927/j.issn.1673-503X.2016.02.003 Abstract ( 368 )   PDF (4403KB) ( 393 )   Save Using intensive and conventional meteorological data, geostationary satellite infrared cloud image and Doppler weather radar monitoring products, precipitation features, environment conditions, water vapor transport, energy field, evolution characteristics of mesoscale cloud, horizontal and vertical distribution of radar reflectivity during a heavy rain event on August 19 to 22, 2010 in Liaoning province were analyzed.The results indicate that there are two rainfall stages in this period, i.e.cold vortex moving east and low vortex moving north.In general, the heavy rain is characterized with large amount precipitation, long duration, wide range and strong local outbreak.Westerly long wave trough is stable.Subtropical high and Japan Sea high are maintained, so the situation of "east low and west resistance" is obvious.The upper and lower systems are coupled, including northeast cold vortex, high-level divergence, wind shear in the lower troposphere, low level jet and surface cyclone and so on.The dry cold air from the north and warm humid air from the south converge over the torrential rain region, and vapor conditions for the severe rain is favorable.With the cold frontal moving eastward, lifting conditions grows by the energy front.Many small-scale and mesoscale convective clusters develop into mesoscale convective complex (MCC).Areas of cold cloud anvil could decide ranges of precipitation.Directions of the echo long axis and echo movement are parallel, thus "train effect" is seen on the radar echo imagery during this precipitation period and leads to local strong precipitation.Meanwhile, radar echo has the characteristics of backward propagation and low centroid which is similar to the tropical heavy rainfall. References | Related Articles | Metrics

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Study on dynamic system of explosive cyclone causing a snowstorm in Heilongjiang province REN Li, ZHANG Gui-hua, ZHOU Yi-han, ZHAO Ning, WANG Chun-hua 2016, 32 (2):  28-36.  doi: 10.11927/j.issn.1673-503X.2016.02.004 Abstract ( 262 )   PDF (2979KB) ( 348 )   Save Using the data of comprehensive observations from weather stations and the NCEP reanalysis data, circulation features and increasing process of explosive cyclone resulted in a snowstorm on November 25, 2013 over Heilongjiang province were analyzed.On this basis, distribution characteristics and vertical structure of vorticity advection and upper and lower jet were studied, so is the contribution of vorticity advection, positive and baroclinic of moist potential vorticity (MPV) to explosive cyclone.Dynamic mechanism of this explosive cyclone was discussed.The results show that cyclone center is under the positive vorticity advection zone in front of upper trough for this event.The positive vorticity convection makes isobaric surface reduced, thus cyclone maintains and develops.The surface cyclone is always located on the left front of the South upper jet core and the right rear of the North upper jet core.The dynamic effects of the two upper jets cause strong divergence in high troposphere.The coupling of high-low jet induces high divergence area overlaying on the top of low convergence area, which consequently leads to intense ascending movement.Thus, it increases intensity of cyclone development and snowfall.Strong baroclinicity is favorable to development of explosive cyclone.The burst of the cyclone is closely associated with the distribution and evolution of the moist potential vorticity.The downward spread of high MPV from the upper troposphere is also of an advantage to the cyclone development.When the equal ξmpv1 curve of the upper troposphere tends to quasi level condition, the cyclone gradually weakens.Increased atmospheric moist baroclinity can lead to increase vertical vorticity significantly, which accelerates development of explosive cyclone.The change of vertical vorticity is lagged behind wet baroclinicity. References | Related Articles | Metrics

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Remote response of autumn precipitation to previous oceanic and atmospheric signals in Liaoning province FANG Yi-he, GONG Qiang, ZHAO Lian-wei, WANG Xiao-tao, ZHOU Xiao-yu, CUI Yan, REN Chuan, WANG Dang, WEN Ri-hong 2016, 32 (2):  37-43.  doi: 10.11927/j.issn.1673-503X.2016.02.005 Abstract ( 278 )   PDF (2001KB) ( 577 )   Save In order to find previous oceanic and atmospheric signals which can significantly influence autumn precipitation in Liaoning province and provide theoretical basis to support autumn climatic forecast, the abnormal characteristics of autumn precipitation were analyzed based on the monthly mean precipitation data from 53 weather observational stations during 1961 to 2012, the NCEP/NCAR monthly mean reanalysis data of geopotential height field and sea level pressure field, and monthly mean sea surface temperature data reconstructed by the NOAA.Meanwhile, previous oceanic and atmospheric signals of autumn precipitation were sought in Liaoning province by a correlation analysis method, and then a prediction equation was established by a multiple linear regression method.The results indicate that the first mode's spatial vector of EOF analysis for the autumn precipitation anomalies percentage shows a consistent abnormal variation characteristic over the whole Liaoning province, and the autumn precipitation anomalies percentage is in a decreasing trend year by year.The North Atlantic SST tripole in previous May, July and August, the Tropical India Ocean Dipole (IOD) in May and the North Pacific Oscillation in May can influence the first mode of the autumn precipitation in Liaoning province, and they can be used as forecast factors of autumn precipitation.Their positive phases correspond to abundant autumn rain in Liaoning province, and vice versa. References | Related Articles | Metrics

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Characteristics of concentrations of main air pollutants at Chaoyang District,Beijing ZHANG Zi-yue, LI Yan, DAI Gao-ju, WANG Wei-qi, CHENG Yue-xing 2016, 32 (2):  44-51.  doi: 10.11927/j.issn.1673-503X.2016.02.006 Abstract ( 385 )   PDF (917KB) ( 793 )   Save Using monitoring concentration data of PM2.5, O3, NO, NOx, CO and SO2 from 2011 to 2013 at national weather station of Chaoyang district of Beijing, variation of concentrations of 6 air pollutants in different time scales were analyzed.The results show that PM2.5 concentration is of a significantly increasing trend and the number of days with heavy pollution grade is also increasing.There is no significant trend for annual average concentration of the other five gaseous pollutants.However, they have obviously seasonal variations.The O3 concentration is high in summer and low in winter, while it is opposite to concentrations of PM2.5, NOx, CO and SO2.The latter is related to the increase of pollutant emission in heating period of winter.The curve of diurnal variation for concentrations of pollutants is bimodal except O3 (unimodal), which may be related to human activities and weather conditions.The diurnal variations of pollutants' concentrations at Chaoyang district differ significantly from those at Baolian, Shunyi and Shangdianzi stations which represent urban area, inner and outer suburbs of Beijing respectively.Among them, difference of PM2.5 concentration is the most significant.The diurnal variation of PM2.5 concentration is bimodal at Chaoyang station, three peaks at Baolian station, and unimodal at Changping and Shangdianzi stations.The single peak occurs at night in the latter two stations.Urbanization development in different regions differs each other, which leads to significant differences in local pollutants' concentrations. References | Related Articles | Metrics

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Characteristics of air quality and its relationship with meteorological conditions in Jinzhou BAI Xue, ZHANG Cui-yan, JI Yuan, YANG Gui-juan, ZHANG Fang, SHI Hong-ting, WEN Zhou 2016, 32 (2):  52-58.  doi: 10.11927/j.issn.1673-503X.2016.02.007 Abstract ( 331 )   PDF (975KB) ( 481 )   Save Using air quality index (AQI) and the daily mean concentration data of air pollutants in Jinzhou and corresponding meteorological data from March of 2014 to February of 2015, temporal and spatial characteristics of air quality and its relationship with meteorological conditions were analyzed.The results show that the frequency of the air quality with good grade is 62% in Jinzhou, while those with light pollution and excellent air quality grades are 23% and 6% respectively.The primary pollutants are PM2.5, PM10, SO2 and O3 in Jinzhou.Air quality is the worst in October and February, while it is the best in September when the number of days with excellent and great air quality grades reaches 97% in this month.Air quality is the worst at Tian'an Street, and its concentration of SO2 is 5 times higher than that at Baigu Street.The main influence systems are terrain trough pattern, Mongolia low circulation pattern and uniform pressure field when the air pollution grade is above slight contamination.Precipitation has good cleanup effect for pollutants, especially for PM10.Dust weather can cause serious air pollution.Presence of inversion temperature is not favorable to the diffusion of pollutants.The lower the bottom height of inversion layer is, the more serious air pollution is.A regression equation of AQI is established and the fitting results suggest that the estimated values are consistent with observed values, especially in spring. References | Related Articles | Metrics

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Polarization-difference parameterization in estimating liquid water path based on AMSR-E data WANG Ying, LI Guo-chun, GAO Yang-hua, DU Qin, ZHAO Zi-qi 2016, 32 (2):  59-65.  doi: 10.11927/j.issn.1673-503X.2016.02.008 Abstract ( 293 )   PDF (1686KB) ( 509 )   Save Cloud liquid water (vertically-integrated cloud liquid water) is a key parameter in meteorology and cloud physics, and its quantitative measurement is important to climate change, numerical weather prediction (NWP), and severe weather monitoring.Using a combination of the space-borne microwave radiometer AMSR-E and the Moderate Resolution Imaging MODIS with AUQA, relationship between microwave polarization channel bright ness temperature and atmospheric moisture ω was established, and the polarization-difference parameterization (PDP) was improved.The results indicate that cloud liquid water path can be directly retrieved by the Advanced Microwave Scanning Radiometer for earth observing plan (EOS) (AMSR-E) polarization-difference signals at 36.5 GHz and 89 GHz, and the resolution could reach 1 km according to retrieved ω of MODIS.Retrieval of cloud liquid water path from AMSR-E and the presented cloud image by MODIS conforms completely.Compared with the retrieved products from the NCEP 1°×1° 6 h vertically-integrated cloud liquid water data, the error is less than 0.04 kg·m-2. References | Related Articles | Metrics

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Study on impact of polar vortex on north Pacific storm track and its possible mechanism LIU Ming-yan, LI Fei, ZHENG Shi, ZHOU Xiao-yu, CUI Yan, ZHAO Chun-yu, WANG Ying, GONG Qiang, ZHANG Hai-na 2016, 32 (2):  66-71.  doi: 10.11927/j.issn.1673-503X.2016.02.009 Abstract ( 221 )   PDF (2040KB) ( 460 )   Save Based on the NCEP/NCAR reanalysis data from 1969 to 2013, the impacts of the northern polar vortex on the North Pacific storm track and its possible physical mechanism in recent 45 winters were analyzed.The results show that storm track is mainly located in the range of 120°E-120°W, 30°-60°N, and the strongest disturbance center is near 45°N.Singular Value Decomposition (SVD) suggests that there are two major coupled modes between the polar vortex and storm track.The first coupled mode depicts that the storm track is stronger (weaker) in the vicinity of its long-term mean locations while the polar vortex is stronger (weaker) in the polar region.The second mode depicts that as the polar vortex increases and shifts to the North Pacific, the storm track comparing to its mean state is stronger in the south of its long-term mean locations.On the contrary, as the polar vortex increases and moves to the north America, the storm track comparing to its mean state increases in the north of its long-term mean locations.A regression analysis further suggests that the anomalous change of polar vortex may give rise to change at 500 hPa geopotential height, and then change the East Asia westerly jet and the baroclinicity in the upstream of the storm track, and finally the storm track itself. References | Related Articles | Metrics

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Responses of extreme energy consumption of typical office building to climate in Tianjin SHI Jun, LI Ming-cai, CAO Jing-fu, GUO Jun, XIONG Ming-ming 2016, 32 (2):  72-78.  doi: 10.11927/j.issn.1673-503X.2016.02.010 Abstract ( 269 )   PDF (747KB) ( 566 )   Save The study simulated heating and cooling energy consumption of typical office building during 1981 to 2010 in Tianjin based on a TRNSYS energy simulation software.Daily or hourly extreme energy consumption was determined by a percentile method and the response of extreme energy consumption to climate was analyzed in order to provide references for energy conservation of typical office building.The results show that the number of extreme heating energy consumption days is in a decreasing trend, while that of the cooling is in an increasing trend.Both are not significant at a confidence test.Also, the percentage of extreme energy consumption to the total does not change significantly.The extreme heating energy consumption is mainly influenced by temperature and wind, whereas the cooling is dominantly related to temperature, moisture and solar radiation.The dry bulb temperature, wet bulb temperature, wind speed and solar radiation influence the hourly extreme heating energy consumption.There is a delay of hourly extreme heating energy consumption on wind speed and solar radiation.On the other hand, wet bulb temperature and solar radiation influence the hourly extreme cooling energy consumption.No delay is found in the impacts of solar radiation on hourly extreme cooling energy consumption, while the response to wet bulb temperature delays 2-3 hours.Building energy conservation design and operation phases should therefore fully take into account of the different meteorological factors in winter and summer. References | Related Articles | Metrics

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Characteristics of sunshine duration from 1961 to 2013 in Bayingolin Mongol Autonumous Prefecture LIU Qiang-ji, WU Sheng-li, FANG Liang, HU Xue-ying 2016, 32 (2):  79-88.  doi: 10.11927/j.issn.1673-503X.2016.02.011 Abstract ( 327 )   PDF (1860KB) ( 739 )   Save Based on daily sunshine duration, temperature, precipitation, wind speed and relative humidity at 7 weather stations in Bayingolin Mongol Autonumous Prefecture(Bazhou) of Xinjiang Uygur Autonomous Region from 1961 to 2013, temporal and spatial trends of annual and monthly as well as seasonal sunshine duration and its influence factors were analyzed by methods of a linear fitting, a 5 years sliding mean, an accumulated anomaly and a Mann-Kendall mutation test.The results indicate that annual average sunshine duration obviously decreases at the rate of 46.1 h per decade, so are the four seasonal values at the rates of 3.6 h per decade in spring, 16.3 h per decade in summer, 12.1 h per decade in autumn and 14.1 h per decade in winter respectively.The order of contribution to the change of annual sunshine duration from high to low in turn is summer, winter, autumn and spring.The maximum and minimum sunshine duration occur in August and December and account for 9.9% and 6.0% of the total annual sunshine duration respectively.The monthly sunshine duration are in a decreasing trend except in April.An abrupt change occurs in 1985 for annual sunshine duration, 1988 for summer sunshine duration, 1984 for autumn sunshine duration and 1985 for winter sunshine duration, while there is not the abrupt change for spring sunshine duration.Annual sunshine duration has a negative correlation with annual mean temperature, precipitation and relative humidity, while it has a positive correlation with wind speed. References | Related Articles | Metrics

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Characteristics of sunshine duration and its influencing factors in Shenyang from 1980 to 2014 MU Chen-ying, XU Quan-hui, ZHANG Jing, LI Shi, SONG Xiao-wei, ZHAO Feng, ZHANG Yu, QIU Mei-juan 2016, 32 (2):  89-94.  doi: 10.11927/j.issn.1673-503X.2016.02.012 Abstract ( 509 )   PDF (1178KB) ( 843 )   Save Based on monthly sunshine duration, annual low cloud amount, annual total cloud amount, annual precipitation and number of annual precipitation days at 7 weather stations in Shenyang from 1980 to 2014, climate characteristics of annual and seasonal sunshine duration were analyzed by a climatic trend method.The correlation relationships were discussed between sunshine duration and its influencing elements.The results indicate that the annual and seasonal sunshine duration in Shenyang are in decreasing trends from 1980 to 2014.Annual mean sunshine duration in Shenyang reduces at the rate of 74.5 h per decade, and it is less than average in the recent 35 years after 2002.There is a significantly decreasing tendency in seasonal sunshine duration at the rates of 11.8-27.1 h per decade, and the order of decreasing amplitudes ranks from high to low as summer, autumn, spring and winter.Spatial distribution of annual sunshine duration in Shenyang decreases from the north to south.Sunshine duration in each weather station is in a decreasing trend.Annual sunshine duration is in a significant negative correlation with precipitation, total cloud amount, low cloud amount and number of precipitation days, especially with the latter three elements. References | Related Articles | Metrics

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Study on rice chilling injury index in Yunnan province WU Yong-bin, CHEN Dan-ni, ZHANG Ming-da, ZHU Bin, DUAN Chang-chun 2016, 32 (2):  95-99.  doi: 10.11927/j.issn.1673-503X.2016.02.013 Abstract ( 304 )   PDF (572KB) ( 389 )   Save Impacts of altitude changes on growth and yield of rice as well as photosynthesis characteristics were analyzed based on rice potted and carrying experiment at 4 sites of different altitudes from April to October of 2013 in Dongchuan region in Yunnan province.The critical altitudes which make the maximum differences of rice growth for japonica rice and indica rice were ascertained.The chilling injury indexes of rice at elongation, blooming and fructicative and milk-ripe stages were determined combining synchronous meteorological observation data.The results show that temperature change with increasing altitude influences greatly growth indexes of indica rice and japonica rice and their photosynthesis, especially for japonica rice.The critical altitude of the maximum difference for indica rice growth is from 1500 m to 1800 m, while that for japonica rice growth is from 1800 m to 2100 m.At the jointing stage, the low temperature and chilling injury indexes for indica rice and japonica rice are defined as 19.6℃ and 17.2℃;both are 20.5℃ and 18.1℃ at the blooming and fructicative stage;they are 19.1℃ and 16.7℃ at the milky stage, respectively. References | Related Articles | Metrics

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Dynamic forecast of winter wheat yield based on an integral regression method in Gansu province JIA Jian-ying, LIU Yi-feng, PENG Ni, WAN Xin, LIANG Yun, WANG Xiao-wei, SHEN En-qing 2016, 32 (2):  100-105.  doi: 10.11927/j.issn.1673-503X.2016.02.014 Abstract ( 204 )   PDF (629KB) ( 672 )   Save Winter wheat is one of the major grain crops in Gansu province, so it is important to forecast its yield dynamically for agricultural production and food security.Based on daily meteorological observation data at 16 weather stations and winter wheat yield data of Gansu province from 1985 to 2013, the main meteorological factors and the key periods influencing winter wheat yield in Longzhong, Longdong and Longnan regions in Gansu province were analyzed according to principles of integral regression.Dynamic forecast models for winter wheat yield in the last ten days of March, April and May were established.The results show that the precipitation and temperature have great influence on winter wheat yield.Increased precipitation has clearly positive effect on the winter wheat yield, especially at the fallow period and reviving jointing stage of winter wheat.Warmer temperature has an obviously negative effect on winter wheat in seedling-before winter stage and jointing-booting stage, whereas warming has a positive effect on winter wheat in late winter-reviving stage in Longzhong region and Longdong region.Forecast verification test in the recent five years suggests that average accuracy rate of the dynamic yield forecasting model reaches above 96%, which can meet the demand by operational service. References | Related Articles | Metrics

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Determination of weight coefficient in agro-meteorological yield prediction QIU Mei-juan, SONG Ying-bo, WANG Jian-lin, WANG Dong-ni, QU Si-miao, REN Jing-quan, WU Ding-rong, LIU Jian-dong 2016, 32 (2):  106-111.  doi: 10.11927/j.issn.1673-503X.2016.02.015 Abstract ( 315 )   PDF (753KB) ( 454 )   Save In the crop yield prediction based on climate suitability index, the determination of weight coefficient was of vital importance to the results.Using winter wheat in Shandong province as a case study, weight coefficient of each ten-day was determined by methods of an absolute value, normalization and a correlation coefficient.Correlations among climate suitability indexes calculated by the above methods and with meteorological yield were analyzed, and the optimal one was used to dynamically predict wheat yield.The results indicate that the correlation between meteorological yield and climate suitability index obtained by the correlation coefficient method almost all passes a significant test of the 0.01 level compared with the other two methods, which can reflect the relationship between the development of winter wheat with change of climatic conditions.The accuracy rate of the historical fitting for the established model is above 94.5%, and the standardized root mean square error (n-RMSE) is less than 7.0%, showing the excellent performance of the model.The results of yield dynamic prediction during 2010 to 2011 suggest that the mean accuracy rate is above 93.0% and most are above 96.0%, which can meet the service needs. References | Related Articles | Metrics