Table of Content

28 February 2015, Volume 31 Issue 1 Previous Issue    Next Issue

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Science issues on global warming ZHAO Zong-ci,LUO Yong,WANG Shao-wu,HUANG Jian-bin 2015, 31 (1):  1-5.  Abstract ( 589 )   PDF (420KB) ( 1054 )   Save  The working group 1 of IPCC has published the fifth science assessment report in 2013. Based on lots of evidences of observations and simulations by climate models, it continues to emphasize the key point that the global is warming at the present time and continues to warm in the future due to increasing human emissions. Several scientific issues of global warming in this paper will be summarized, such as differences among several datasets of observed global surface air temperature, effects of different basic climate periods, detection and attribution of global warming during the 20th century, and the trends of global temperature change in the 21st century. It raises the further research issues of global warming in the future. The key points are: the qualities of the observed data should be raised; it should be noticed that the different basic climate periods have various values; the capabilities of both decadal and interdecadal variabilities as simulated by the climate models would be improved, and the reasons of the hiatus in global mean surface warming of the past 15 years have to be studied, therefore to revise the climate models; the uncertainties of projected the global climate change in future are from climate model differences, and various anthropogenic emission scenarios, as well as impacts of internal variability of climate system and actions of the natural external forcing. Related Articles | Metrics

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Comparative analysis of two typhoons affecting Liaodong Peninsula with similar track LI Hui-lin,GAO Song-ying,XU Lu-lu,SONG Li-li,LI Rui-han,WANG Chun-xia 2015, 31 (1):  6-13.  Abstract ( 505 )   PDF (2918KB) ( 601 )   Save  Two typhoons called Muifa (1109) and Bolaven (1215) formed over the Yellow Sea area both moved northward and affected Liaodong Peninsula. There were errors in the forecast of precipitation and wind intensity for these two typhoon processes. Based on the conventional meteorological data, observational data from intensive automatic weather stations and the NCEP reanalysis data, the above two typhoons were compared and analyzed. The results show that low trough at mid-high latitude (from 110°E to 120°E) of 500 hPa, the Okhotsk blocking high, the change of Subtropical High intensity and shape, and the northern cold air all significantly affect the northward track and intensity of the typhoons. The northern cold air was important to precipitation caused by northward typhoon, and spiral rain band around the typhoon leads to precipitation. The Japan Sea High ridge stretching to northeastern China influences significantly gale. The duration of typhoon impact is closely relative to involvement of cold air after landfall. Related Articles | Metrics

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Application of satellite and radar data to rainstorm numerical prediction WANG Xue-lian,LI Ying-hua, LIU Li-li,QIU Xiao-bin,CHEN Jing,XIE Yi-yang 2015, 31 (1):  14-19.  Abstract ( 431 )   PDF (2557KB) ( 891 )   Save Using a mesoscale numerical model ARPS (Advanced Regional Prediction System) data analysis system (ADAS), CINRAD/SA and SB Doppler radar reflectivity and Fengyun-2E satellite data were implemented in the model field. A heavy rainstorm process on July 21, 2012 in the north China was simulated using a high resolution mesoscale numerical model (WRF). The results show that the Doppler radar and satellite data are helpful for improving the accuracy of simulated heavy rainfall because of the corrections on the water vapor in lower atmospheric layers, especially for the position of falling area of precipitation and its maximum amount. At the same time, the slow development of prediction by WRF model is improved after adding the assimilated satellite and radar data. Comparison between radar and satellite assimilation suggests that the former can improve the prediction of precipitation within 6 hours, while the latter can improve precipitation forecast within 24 hours. Using the satellite and radar data, precipitation forecast is closer to the observation, especially for the beginning time, intensity and range of precipitation. Related Articles | Metrics

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Diagnostic analysis of a large range of spring fog process along the eastern Yangtze river in Anhui province FU Wei1 HE Dong-yan2 ZHU Qi1 ZHU Fu-rong1 DU Wen-rong1 LI Luan1 2015, 31 (1):  20-27.  Abstract ( 458 )   PDF (2269KB) ( 467 )   Save  Using surface observed data, upper sounding data, NCEP reanalysis data, wind profile radar data and meteorological station data along the motorway in Wuhu, the circulation and physical conditions about formation and dissipation of a fog process on March 6, 2012 along the eastern Yangtze river in Anhui province were analyzed. The results show that this spring fog process belongs to radiative fog. There are mainly westerly to southwesterly winds over the fog area when a heavy fog occurs, without significant cold air. It is controlled by the equal high pressure field in Anhui province, so it is beneficial to the formation and maintenance of fog. The physical conditions about formation and dissipation of the fog show that enough water vapor and moisture condensation caused by long wave radiative cooling are important reasons of the heavy fog formation. The inversion layer formed by radiative cooling near the ground benefits the maintenance of fog, and the fog becomes thicken and develops with rising of the inversion layer near the ground. Stability stratification formed by the inversion layer of low level prevents moisture transport upwards. Low wind speed near the surface, weak vertical shear of wind in middle and low atmosphere, turbulence in low layer, no obviously ascending motion in middle atmosphere, these all constitute the favorable dynamical conditions of fog formation, and they can make the wet layer thickened and prevent moisture transport upwards, which is also beneficial to formation and maintenance of fog. After sunrise, the solar radiation becomes stronger, and conditions beneficial to formation and maintenance of fog like radiation cooling, inversion layer and dynamical conditions disappear, so the fog dissipates. Related Articles | Metrics

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Characteristics of short-time heavy precipitation from 2008 to 2012 in Nanjing SHEN Cheng,YAN Ting-bai,LIU Dong-qing,LI Jing2 2015, 31 (1):  28-33.  Abstract ( 638 )   PDF (958KB) ( 1102 )   Save Based on hourly observed data from automatic weather stations in Nanjing from 2008 to 2012, annual, monthly and daily variation of short-time heavy precipitation and their spatial distribution were analyzed. The results indicate that the number of short-time heavy precipitation more than 50 mm/h-1 is in a significantly increasing trend from 2008 to 2012. Short-time heavy precipitation mainly occurs during June to September, especially during July and August with the highest days and strongest intensity. For spring rain period, short-time heavy precipitation often occurs in the early morning; for Meiyu period, it is often in the morning and early evening; for typhoon and flood period, it is also in the morning. In general, short-time heavy precipitation seldom occurs during midnight to early morning, while it occurs often about early evening. The spatial distribution characteristics of short-time heavy rain have obvious differences between urban and rural areas. The effect of urbanization does not lead to local heavy rain in the urban area, while it only makes the convection more active in the urban area than in the rural area under large scale weather system. Also, precipitation in the lower reaches of urban area enhances because of the above reason. Related Articles | Metrics

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Temporal and spatial characteristics of heavy rainstorm from 1960 to 2011 in Liaoning province YANG Qing1 HAN Xiu-jun1 GAO Song-ying2 YAN Qi1 LU Bing-hong 3 TIAN Li1 2015, 31 (1):  34-42.  Abstract ( 659 )   PDF (1470KB) ( 424 )   Save  Based on daily and hourly precipitation data at 61 national weather stations in Liaoning province from 1960 to 2011, the spatial and temporal climate change characteristics of heavy rainstorm were analyzed statistically. The result shows that the number of average annual rainstorm is 6.5 days, and annual average stations where heavy rainstorms were observed are 17.5 stations. High-incidence areas of two rainstorms are located in the southeast of Liaoning and southwestern to southern seacoast of Liaoning province, respectively. Regional and local heavy rain easily occurs in the area of high-incidence rainstorm because of influence of typhoon, Jianghuai cyclone, North China cyclone, Mongolia cyclone etc. and local geographical conditions in the southeast of Liaoning province. As a result, the frequency of heavy rain is high and precipitation changes largely. Extreme of precipitation and intensity both are large, and the strongest rainfall is up to 212 mm/h-1 and appears in Fengcheng. On the other hand, a regional heavy rain also easily occurs in the area of high-incidence rainstorm because of influence of typhoon, North China cyclone and topography, so extreme precipitation and intensity are also larger in the south to southwest of Liaoning province. However, the centers of maximum precipitation and extreme intensity are not consistent with that of the number of rainstorm day. Extreme of regional rainstorm is a major contribution to that of rainstorm. Hourly variation of precipitation intensity has a peak at 08:00 and a valley at 20:00. Heavy rainstorm day mainly appears from the last ten days of July to the first ten days of August, and it is higher in August than in July. The first and last regional heavy rains are influenced by Jianghuai cyclone and both occur in the south of Liaoning province. It is a significant cycle for the heavy rain day and its main inerdecadal cycle is 10 years, while main cycles of regional and local heavy rain are 36 years and 10 years respectively. Forecast suggests that the heavy rain still often occurs in the next 6 years in Liaoning province, especially the local heavy rain. Related Articles | Metrics

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Temporal-spatial characteristics of precipitation day in different levels in Beijing-Tianjin-Hebei from 1961 to 2012 LIU Jin-ping,HAN Jun-cai,XIANG Liang,FAN Yin-qi 2015, 31 (1):  43-50.  Abstract ( 431 )   PDF (3463KB) ( 885 )   Save  Based on daily precipitation data at 78 weather stations of Beijing-Tianjin-Hebei region during 1961-2012, spatial and temporal evolution of precipitation day at different levels were analyzed using methods of a trend analysis, a Morlet wavelet and an empirical orthogonal function (EOF). The results show that it has not a significant trend for precipitation day at different levels in the recent 52 years in the study area. Spatial distribution of the total rain and light rain days is in a decreasing trend from northwest to southeast. The moderate and heavy rain days have two similar centers of high values, and both are located in the northeast of Beijing-Tianjin-Hebei region and in the west of Taihangshan mountain region, respectively. However, the spatial distribution of torrential rain day has no significant feature and it is random. Both total and light rain days have two time-scale oscillation periods i.e. 13 years and 6 years, so are moderate, heavy and torrential rain days i.e.15-18 years and 8-11 years. The first mode of EOF analysis suggests that the number of precipitation day in all levels has a better consistency in the region. The second mode of EOF analysis suggests that total rain day, light, moderate and heavy rain days have an opposite phase in the north and south, and torrential rain day is more (less) in the northeast and east of study area, less (more) in middle and west of study area. Related Articles | Metrics

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Characteristics of regional high temperature heat wave events over China under SRES A2 scenario YANG Hong-long,PAN Jie,ZHANG Lei 2015, 31 (1):  51-59.  Abstract ( 473 )   PDF (1890KB) ( 972 )   Save With global warming, how to control high temperature and heat wave events will be one of the difficult problems that modern cities have to consider. An analysis of simulated distribution of the present (1961-1990) and future (2071-2100) high temperature heat wave events by three runs from a regional model (Providing Regional Climates for Impacts Studies, PRECIS) in China under the IPCC SRES A2 scenario was presented. The results indicate that PRECIS could simulate better the frequency, intensity and duration of the high temperature and heat wave events as well as corresponding atmospheric circulation for the basic period (1961-1990). Compared with those of the basic period, intensity of high temperature and heat wave events will rise, and increasing amplitude of its frequency will exceed 100% and its duration will increase by 30% or above. Also, observed and simulated results suggest that high temperature and heat wave events have a close relation to positive anomaly of 500 hPa geopotential height field over Wuhan and Harbin regions. Under future scenario, positive anomaly of 500 hPa geopotential height field will be in a increasing trend in the above two regions, and it suggests that it will probably be more serious high temperature and heat wave events in these regions. Related Articles | Metrics

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Refined forecast of cloud cover---a case study in Yuzhong ZHAO Wen-jing,ZHAO Zhong-jun,SHANG Ke-zheng,WANG Shi-gong,NING Gui-cai 2015, 31 (1):  60-66.  Abstract ( 471 )   PDF (600KB) ( 495 )   Save Based on daily cloud cover data with 3 hours interval and corresponding NCEP data with 6 hours interval from July of 2001 to July of 2011 in Yuzhong of Gansu province, relationships between forecast factors built by the NCEP data and forecast object such as the total cloud cover and low cloud cover were analyzed. A series of monthly forecast equations of cloud cover with daily 8 times was established by a stepwise regression analysis method and were tested by back substitution, and then prediction effect was checked using data of 2012. The results show that cloud cover is mainly affected by the whole layer humidity, vertical velocity, instability energy, trough intensity index and divergence of moisture flux in 700 hPa, especially the first two elements. Forecast effect of total cloud cover is better than that of low cloud cover; average errors of total cloud cover and low cloud cover are about 20% and about 30%, respectively. Tendency of predicted values can partly reflect that of observed values. Related Articles | Metrics

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Spatial-temporal distribution of frost day and its response to air temperature changes from 1971 to 2010 in He’nan province JI Xing-jie,LI Feng-xiu,WANG Ji-jun 2015, 31 (1):  67-75.  Abstract ( 590 )   PDF (2260KB) ( 377 )   Save Based on frost date data at 110 weather stations of He’nan province from 1971 to 2010, spatial and temporal distribution characteristics of the first and latest frost dates and frost-free period as well as its response to air temperature changes were analyzed by methods of a linear trend and a single correlation, and its abrupt change feature was also discussed based on the analysis using a Mann-Kendall method. The results show that average frost-free period is 221.3 days. Latitude is significantly negative correlation with the first frost date and frost-free period, and both correlation coefficients are -0.806 and -0.707 respectively; it is significantly positive correlation with the latest frost date, and correlation coefficient reaches 0.557. The first frost date delays at the rate of 2.6 days per decade (p<0.01); the latest frost date has no significant trend; the frost-free period increases at the rate of 4.7 days per decade (p<0.01). The abrupt change of the first frost date, last frost date and frost-free period all appear in 1998. Trends of the first frost date, last frost date and frost-free period differ in different regions. The first frost date delays in all six regions, especially in the west of He’nan province with 3.5 days per decade (p<0.01). The latest frost date only advances in the west and south of He’nan province. The frost-free period extends obviously except in the east of He’nan province, especially in the west with 7.7 days per decade (p<0.01). For the spatial distribution of frost period at 110 weather stations, the areas in which the first frost date is postponed significantly, in which the last frost date appears obviously earlier and in which the frost-free period extends obviously mainly include the western and southern parts of He’nan province. The first frost date is significantly related to temperature of October, while the last frost date is markedly correlated with temperature of March. Changes of the first frost and latest frost dates are mainly attributed to increasing air temperature, especially increasing average minimum air temperature in He’nan province. The first frost date delays and the latest frost date is in advance, which leads to frost-free period extending. Related Articles | Metrics

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Spatial-temporal characteristics of delayed cool injury for rice from 1961 to 2010 in Heilongjiang province GONG Li-juan,LI Shuai,JIANG Li-xia,ZHU Hai-xia 2015, 31 (1):  76-83.  Abstract ( 741 )   PDF (1948KB) ( 515 )   Save Based on the mean air temperature data at 62 weather station of Heilongjiang province from May to September during 1961-2010 and a standard on cool injury of rice (CIR), spatial and temporal distribution of delayed CIR in mild, moderate and serious grades was analyzed using methods of an accumulated anomaly and a wavelet analysis in order to provide references for prevention of CIR. The results indicate that delayed cool injury of rice occurs mainly in Heihe, Qiqihaer, eastern Harbin, western Mudanjiang and eastern Sanjiang plain. There is a significantly variation for delayed CIR during 1961-2010 in Heilongjiang province. The CIR has a turning point in 1994 and seldom appears after 1994. The CIR decreases significantly after 2000. The cycles of delayed CIR are 21 years and 9 years for mild and middle grades respectively, while it is 21 years for serious grade. Related Articles | Metrics

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Analysis of compensation point variation to CO2 with different varieties of winter wheat in North China QIU Mei-juan,LIU Jian-dong,WU Ding-rong,LIU Ling,BI Jian-jie 2015, 31 (1):  84-89.  Abstract ( 380 )   PDF (709KB) ( 375 )   Save  Compensation point to CO2 is one of the key parameters for crop growth model. Systematic measurements of parameters for physiological-ecology of different varieties of winter wheat before 1949 and from1949 to 2005 in North China were conducted using a Licor-6400. Based on these measurements, rectangular hyperbolic photosynthetic models of different winter wheat varieties in North China involving the function of CO2 were fitted in order to determine compensation point to CO2 in different varieties in different time. The results indicate that the compensation point to CO2 decreases with increase of photosynthetic photon flux density (PPFD) in the North China. Under 800 μmol·m-2·s-1 PPFD conditions, the compensation point to CO2 of the wild variety is the highest, reaching 123.40 μmol·mol-1. During 1949-2005, the compensation point to CO2 varies obviously with varieties, with the highest value of 107.07 μmol·m-2·s-1 for Taishan No.1 variety and the lowest value of 57.25 μmol·mol-1 for Hongtutou variety. Difference of maximum and minimum values between different varieties of winter wheat reaches 49.82 μmol·mol-1, and it suggests that compensation point to CO2 changes significantly with evolution of winter wheat varieties in North China. The study establishes rectangular hyperbolic photosynthetic models of seven typical winter wheat varieties in the North China involving the function of CO2, and identifies the compensation point to CO2, which provide the basic data set to develop crop models for evaluation of impact of climate change on agriculture in North China. Related Articles | Metrics

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Responses of growing period and phenological duration of woody plants to climate warming in southwestern Shandong province LI Rui-ying 2015, 31 (1):  90-95.  Abstract ( 438 )   PDF (498KB) ( 620 )   Save The response patterns of growing period and phenological period duration of 7 woody species to climate warming in Southwestern Shandong province were analyzed using a statistical analysis method. The results show that the temperature is in a significantly increasing trend (p<0.01). Under the conditions of climate warming, the spring phenological period interval of woody plants is shortened; the autumn phonological period interval is prolonged, so is growing period. Growing period is obviously longer than phenological period duration. The duration of leaf expansion is negatively correlated with temperature of last month and this month as well as subsequent monthly mean temperature. Correlation between duration of leaf expansion of Firmiana simplex and temperature of current month is significantly negative (p<0.01), while correlation between duration of flowering of Salix matsudana and robinia pseudoacacia, and subsequent monthly mean temperature is positive (p<0.05). The duration of leaf color changing and leaf falling is positively correlated with temperatures of last month and current month as well as ending month, and subsequent monthly mean temperature. Among them, the significant correlation between Salix matsudana and the temperature is also found (p<0.05). The growing period of woody plant is positively correlated with temperature, and the growing period of Salix matsudana is more sensitive to climate warming, following by those of Ulmus pumila、Firmiana simplex and Melia azedarach, The plant growing periods will be prolonged 3.0-20.0 days, 5.0-14.0 days and 2.0-18.0 days when annual mean temperature, annual mean maximum temperature and annual mean minimum temperature increase by 1℃, respectively. Related Articles | Metrics

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Change of climatic seasons between urban area and suburb in Wuhan from 1960 to 2009 CHEN Cheng,GU De-gao,LU Yang 2015, 31 (1):  96-100.  Abstract ( 476 )   PDF (471KB) ( 499 )   Save Using daily average temperature data at two weather stations in urban area and suburb of Wuhan from 1960 to 2009, the beginning date and ending date of seasons, seasonal duration and their trends as well as differences were analyzed using a method of division of same climatic seasons. The results indicate that the beginning dates of spring and summer during 1980-2009 are in advance of 10 days and 5 days in urban area of Wuhan than in suburb, while those of autumn and winter is prolonged. Summer duration is 12 days longer in urban area than in suburb, while winter and spring duration is 6 days and 5 days shorter in urban area than in suburb. Mean beginning dates of four seasons have no significant difference between urban area and suburb during 1960-2009. However, the first and latest beginning dates differ significantly for annual variation of four seasons. The beginning dates of spring and summer both are in advance in urban area and suburb, while those of autumn and winter are prolonged. In general, seasonal variation is obvious in urban area, while only the beginning date of autumn changes significantly in suburb. Summer duration is prolonged significantly in urban area, while winter duration is shortened. Spring and autumn duration in urban area has no significant change, so is seasonal duration in suburb. Variation of the beginning date of seasons and seasonal duration during 2000-2009 in Wuhan is caused by rapidly urban development as an important city in the middle of China. Related Articles | Metrics

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BCC_CSM climate system model tuning and climate simulation verification WEI Min 2015, 31 (1):  101-105.  Abstract ( 431 )   PDF (2214KB) ( 222 )   Save  In order to improve the computational efficiency of BCC_CSM climate system model, porting and tuning work of BCC_CSM on IBM high performance computing system were carried out. According to the requirement of climate prediction production, the model computational efficiency was greatly improved by tuning. With the help of distributed situation of climate variables’ field and quantitative indicators, model simulation performance was verified. The results indicate that computational speed from the modified model is 1.4 times faster than that of the original one. Annual mean surface air temperature distribution is reasonable in ten years (531-540) based on climate simulation of a CMIP5 piControl experiment, and relative error is less than 0.5%. Both of computational efficiency and simulation performance of the BCC_CSM model are met application requirements. Related Articles | Metrics

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Study on disaster risk of typhoon Soulik and its prevention benefit assessment YANG Lin,CAO Chun-rong,LIN Qiu,WEN Ming-zhang,LIN Wen-hua,ZHAO Shan-shan 2015, 31 (1):  106-112.  Abstract ( 458 )   PDF (1437KB) ( 489 )   Save Based on the meteorological dataset of typhoon Soulik，typhoon disaster data in Fujian province since 2000 and the network survey data of typhoon Soulik, pre-assessments of the loss of typhoon Soulik including affected population and direct economic losses were calculated using an estimation of upper and lower limits of a similar analysis method. Risk divisions of typhoon Soulik were carried out using a typhoon risk division method. The results indicate that pre-assessment of typhoon Soulik is consistent with the real disaster losses, and so are risk divisions. The higher risk grade is, the serious disaster loss is. The direct economic loss of most counties with high risk reaches over 10 million Yuan. According to the questionnaires with a 3-level index system of benefit assessment of typhoon prevention and mitigation behavior, all indexes could assess greatly action of the local government, the department and the public. Among them, the local government plays an important role for prevention of typhoon Soulik. Related Articles | Metrics