Table of Content

30 December 2011, Volume 27 Issue 6 Previous Issue    Next Issue

Articles

Select

Forecasting of winter precipitation phase state in Northeast China based on WRF mesoscale model CUI Jin, ZHOU Xiao-Shan, CHEN Li-Qiang, ZHANG Ai-Zhong, YANG Sen, YAN Qi 2011, 27 (6):  1-6.  Abstract ( 730 )   PDF (1613KB) ( 939 )   Save The forecasting of winter precipitation phase state in the Northeast Chinawas attempted with a  mesoscale numerical weather prediction model (WRFV3.1.1). According to the percentage of frozen fraction of precipitation mixing proportion in atmosphere near the ground in water vapor mixing proportion that may condense into precipitation, the rain snow boundary line, sleet area, the transition zone of rain snow were determined. The results indicate that this method could forecast  the distribution areas of rain, snow and sleet and the evolution of precipitation phase state during precipitation process with a relatively good accuracy. The application of these numerical forecast products  could significantly improve the accuracy of weather forecast . Related Articles | Metrics

Select

Variation characteristics of visibility and its main influencing factors in Dandong, Liaoning province ZHAO Hu-Jia, MA Yan-Jun 2011, 27 (6):  7-13.  Abstract ( 712 )   PDF (814KB) ( 686 )   Save Based on the visibility data from the instrument observation and manual observation from June 2007 to November 2009 in Dandong, relationship between these two records was analyzed. The effects of particle concentrations such as PM10, PM2.5 and PM1.0 in the different seasons on the visibility were discussed. The relationship between precipitation intensity and wet removal efficiency of PM was analyzed. The results indicate that the visibility ratio between visual measurement and instrumental measurement is small under the low visibility condition. The proportion of PM10 is larger when visibility is poor, and the mean monthly wind speed is in the negative correlations with the values of PM1.0/PM10 and PM2.5/PM10. The more the weather phenomena are in a month, the poorer the relatively mean monthly visibility is. The change of mean daily mass concentration of PM and the wet removal efficiency of PM to precipitation are related to precipitation intensity. The average visibility values from both visual measurement and instrumental measurement decrease with the increasing of precipitation intensity. Related Articles | Metrics

Select

Temporal distribution character of regional heavy rain from 2001 to 2010 in Liaoning province GONG Ying, CHEN Li-Qiang 2011, 27 (6):  14-19.  Abstract ( 684 )   PDF (1326KB) ( 689 )   Save Based on the hourly precipitation data from automatic weather stations in Liaoning province and the NCEP data (1°×1° resolution), the 25 heavy rain events in the flood seasons from 2001 to 2010 were analyzed in order to obtain the temporal distribution characteristics and typical weather systems of the heavy rain events. The results show that among the 25 heavy rain events, 7 events (28%) have two main rain phases, i.e. there are obviously decreasing precipitation and transformation of weather system between two rain phases. The upper air jet stream is the main weather system at high level (200 hPa) during the heavy rain process. 92% of main weather systems are upper trough at middle level (in 500 hPa). Among 92%, the common influence of upper trough and subtropical high accounts for 57%. 88% of inducing systems is a shear line of the top (or eastern) of cyclone (or inversion trough) at low level (in 800 hPa), and 12% is a shear of saddle field. In general, the weather systems of heavy rain events with two rain phases at high and middle levels do not change in the two stages. The main weather systems are upper jet stream in high level and the common influence of upper trough and subtropical high in middle level (a few of them are only influenced by upper trough). The heavy rain processes with two rain stages are accompanied with the adjustment of the elements fields at low level, especially the adjustment of wind field, which results in the transformation of weather systems at low level or the change of intensity. The adjustment stage of the elements fields at low level is also the interval period of two rain phases. The collocation of weather system and duration of the heavy rain process do not have obvious characteristics for the heavy rain events with two rain stages. That is to say, the heavy rain events in their early period could not be identified whether they could develop into two or more stage rain. 17 events in Dandong and Benxi have the phenomena of abruptly increasing precipitation among 25 heavy rain events, which is related to the location of two cities, namely, Benxi is located in the southeastern Changbai Mountain and the southeast of Dandong is close to the sea. Related Articles | Metrics

Select

Characteristics of a short-time heavy rain along the Huaihe River in Anhui province based on LAPS data LI Ping, GUAN Li, HUANG Yong, DI Jing 2011, 27 (6):  20-27.  Abstract ( 530 )   PDF (3961KB) ( 534 )   Save Based on the Local Analysis and Prediction System (LAPS) data, the mesoscale weather characteristics of a short-time heavy rain process along the Huaihe River of Anhui province were analyzed in order to investigate the forming reasons and weather features of this rain process. The practicability of LAPS data was validated. The results indicate that the main weather system in this process is mesoscale cyclonic vortex. The moving of the cyclonic vortex to the northern Anhui province along the Huaihe River provides a trigger mechanism for the occurrence and development of the heavy rain. The radar precipitation echoes mainly occur in the south side of mesoscale vortex in 850 hPa and during the ascending process of southwest air flow in front of the trough in 700 hPa. The persistent low air jet stream together with the concomitant water vapor provides water vapor conditions and dynamic mechanism for the heavy rain process. The development of radar echo and the evolution of cloud liquid water content are compared, and it finds that the maximum value area of cloud liquid water contents often appears in the area generating newborn monomer of radar echo. The distributions of cloud liquid water contents based on LAPS data are important to forecast the development trend of radar echo and precipitation distribution. Related Articles | Metrics

Select

Simulation analysis of PM10 emission from typically atmospheric pollution sources in winter of 2007 over Shenyang ZOU Xu-Dong, TIAN Xiao-Bo, YANG Hong-Bin, WANG Hong-Yu, LIU Yu-Che, ZHANG Yun-Hai 2011, 27 (6):  28-34.  Abstract ( 773 )   PDF (1522KB) ( 585 )   Save According to PM10 concentration data from 9 typically atmospheric pollution sources in the urban area of Shenyang from December 2007 to February 2008, the monthly averages of meteorological fields and PM10 concentration distributions were simulated using MM5 model coupled with CALPUFF model. The results indicate that the high-pressure controls Shenyang region in winter and the north wind is strong, and the weather situation is usually unfavorable to pollutants diffusion after they are strengthened and weakened. Shear of wind direction and wind speed is obvious in the ground and in high level when it is the westerly wind in high level and wind speed is large, and shear could be strengthened or reduced. The most serious air pollution occurs in February 2007 over the Shenyang city. The pollutants mainly distributes in the south and southeast of Shenyang, especially in the south. The distribution ranges of PM10 concentrations are related to wind filed and topography. The diffusion ranges of pollutants are large and the concentrations of pollutants are small when topography is flat and wind speed is large, and vise versa. Related Articles | Metrics

Select

Comparison of two rainstorm processes in Zhejiang province caused by northeast cold vortex LUO Ling, HU Liang, HE Jin-Hai, LOU Xiao-Fen 2011, 27 (6):  35-42.  Abstract ( 698 )   PDF (4242KB) ( 674 )   Save Two rainstorm processes caused by northeast cold vortex occurred in the early June of 2009 in Zhenjiang province, and both had the different features. Based on the conventional meteorological data, data from automatic weather stations, the NECP reanalysis data and satellite images, the large-scale circumfluence background, dynamical and thermodynamic conditions, water vapor conditions of two processes were compared. The results indicate that weather situation is different because of the differences of temperature fields in middle and low levels and intensity of systems from upstream to downstream. The rainstorm on June 2nd is a continuously regional process and is mainly generated by stratiform cloud. The rain band distribution is zonal. There are large range convergence in low level and divergence in high level. The convergence in low level is stronger than the divergence in high level. The southwest jet steam exists in low level, which provides the important water vapor and dynamical conditions for rainstorm. Atmospheric stratification is stable.By comparison, the rainstorm on June 5th is a severe convection weather process. The distributions of precipitation are uneven, and precipitation intensity is strong and duration is short in this process. There are not large range convergence and divergence areas in high and low levels and southwest jet stream in low level. Water vapor conditions are poor in the early period of precipitation. This process is mainly generated by thermodynamic action, and unstably atmospheric stratification triggers the severe convection weather and results in the local rainstorm. The key points of forecasting are the structures of divergence in high level and convergence in low level as well as southwest jet stream in low level for the first regional rainstorm process, while those are atmospheric stratification instability degree and incursion of dry and cold air from the rear of northeast cold vortex for the second local rainstorm process. Related Articles | Metrics

Select

Spatial-temporal characteristics of activity frequencies of northern cyclone and southern cyclone in East Asia WANG Yan-Ling, WANG Li-Juan 2011, 27 (6):  43-48.  Abstract ( 583 )   PDF (1588KB) ( 667 )   Save Based on the NCEP/NCAR daily reanalysis sea level pressure field data from 1953 to 2007, the spatial-temporal characteristics of activity frequencies of northern cyclones and southern cyclones in East Asia were analyzed. The results show that there are obvious inter-annual and inter-decadal variability for activity frequencies of northern cyclones and southern cyclones. With the inter-decadal climatic jump in the global scale, activity frequencies of northern cyclones have an obviously abrupt change in 1980s. The most activity frequencies of northern cyclones and southern cyclones appear in May and in August, respectively. Northern cyclones are frequent in spring and have two obviously large values centers. The centers are located in the middle of Mongolia and the north of Northeast China, respectively. Southern cyclones are frequent in summer and they are mainly located in the sea regions of the east of China and the south of Japan. The seasonal variations of activity frequencies of southern cyclones and northern cyclones are related to atmospheric circulation. The relationally analytical results of this study could provide the references for knowing well the activity rules of extratropical cyclone in East Asia and forecasting cyclone activity. Related Articles | Metrics

Select

Analysis of main measuring indices of Journal of Meteorology and Environment from 2006 to 2009 LI Li-Guang, LI Chang-Jie, WANG Hong-Bo, ZHAO Zi-Qi, LIU Jing-Miao 2011, 27 (6):  49-52.  Abstract ( 496 )   PDF (448KB) ( 646 )   Save Based on the data from the China national knowledge infrastructure (CNKI) network (http://www.cnki.net), the characteristics of some indices of the Journal of Meteorology and Environment from 2006 to 2009 were analyzed and communication ability of the journal was summarized. The results indicate that citation indicator indices such the total citation frequency, impact factor and non-self citing impact factor are in increasing trends. Of them, the total citation frequency increases from 145 in 2006 to 645 in 2009; impact factor increases from 0.177 in 2006 to 1.389 in 2009; non-self citing impact factor increases from 0.470 in 2007 to 0.989 in 2009. Source journal citation indices such literature sources amount is stable around 90 papers every year. Ratio of funded papers increases from 0.38 in 2007 to 0.78 in 2009. The annual net increasing rates of various indices are greater. Now, the Journal of Meteorology and Environment has been spread over 12 nations and regions. The network loading amount and browsing amount of the Journal of Meteorology and Environment is higher in Asia than in the other continents and the loading and browsing ratios reach 66.11% and 73.71% in Asia respectively, while the ratios are 13.21% and 11.91% in China and both are in one university----Nanjing University of Information Science and Technology. Related Articles | Metrics

Select

Function implementation and application of ″GRPA++ financing processing system″ in meteorological departments WAN Zhi-Hong, LIU Feng-Hui, CHEN Zheng, GU Wei 2011, 27 (6):  53-55.  Abstract ( 940 )   PDF (360KB) ( 497 )   Save ″GRPA++ financial processing system″ was used in meteorological departments since 2010. The financial staff could establish online data set, treat daily financial business, fill and report spreadsheet, and governing units could check debit/credit amount, transactions and ending balance of subordinate units during a certain accounting period or a few consecutive accounting periods by using this system. The system also includes the general ledger for a statistical summary of certain units during a certain accounting period or during several successive accounting periods. The application of ″GRPA++ financial processing system″ has made the daily business operation on-line, strengthened the on-line supervision of governing units and auditors and the management of financial information as well as enforcement of budget, which is important to financial management. At the same time, it enhanced the work efficiency and ensured safety and integrality of financial accounting information. Related Articles | Metrics

Select

Application of satellite cloud image  to monitoring and early warning of heavy fog along the coast LI Yan-Jiang, WANG Xin-Long, JU Li-Ling, GONG Yu, BIAN Qing-He, LU Xian-Mei 2011, 27 (6):  56-65.  Abstract ( 710 )   PDF (6379KB) ( 699 )   Save  Based on FY-2E satellite image from 2005 to 2010, the weather data of 28 heavy fog events along the coast and meteorological data from island weather stations from 2008 to 2010, the satellite cloud image with aerological sounding data, the surface weather chart was overlaid and temperature of the inversion layer profile of temperature field and TBB values were compared with sea surface temperature, and the areas and depth of sea fog, the temperature in fog region in autumn and winter were evaluated with MICAPS 3.0 system by the atmospheric static equation and thermodynamic theory. The results indicate that the fog monitored with infrared image and visible cloud image changes from light fog to heavy fog along the coast of Dalian, Yantai and Tianjin under special circulation background around the Bohai sea regions, and it moves to the north along the coast. The vertical depth of fog reaches 400-600 m, the lapse rate of temperature is 0.02-0.04 ℃/100 m. The difference values of temperature are 1-2 ℃ and 3-5 ℃ between the east and the west directions and between the south and the north directions in the Bohai sea, respectively. Radiative fog and advection fog are associated with weakly high and low pressure fields, respectively. The heavy fog is strengthened for the fog area is covered by the low cloud, while the visibility of the light fog is weakened because of the overlaying of low cloud. The advection fog is mixed into water vapor conveyer belt of low level after it is lifted by the frontal surface, which is indicative to subsequent snowfall or rainfall. The effect of forecasting for these heavy fog events during 2009-2010 is good in terms of the above mentioned method, and it could provide guidelines for selecting the forecasting factors and improving the work flow of forecasting and monitoring operation of heavy fog events. Related Articles | Metrics

Select

Characteristics of annual variations of winter rain/snow and atmospheric aerosol distributions in the north of China WANG Ji-Zhi, LI Duo, YANG Yuan-Qin, WANG Ya-Qiang 2011, 27 (6):  66-71.  Abstract ( 577 )   PDF (736KB) ( 933 )   Save With the rapid development of atmospheric observation technology in recent years, it provides some new observational facts for the analysis of the inter-annual variations of the heavy snow in winter and increases some new understanding. It is considered that the effect of atmospheric circulation on annual variations of winter snowfall is important, while it is just one of most aspects. New observational facts indicate that the inter-annual variations and differences of winter snow may be related to atmospheric aerosol. According to precipitation data from 279 weather stations from 1980 to 2008 and atmospheric aerosol optical depth (AOD) data from 1980 to 2005 in the north of China, the relationships between amount of winter rain/snow and AOD were analyzed. The results indicate that the typical years with more winter rain/snow are 1980, 1984, 1989, 1993, 1998, 2003 and 2006 in the north of China, while those with  less winter rain/snow are 1982-1983, 1985-1988, 1997, 2001 and 2005. The correlation analysis between the total winter snowfall and synchronous AOD in the north of China shows that the annual variation of winter rain/snow is in a positive correlation with AOD550nm, and the correlation coefficient is significant at 0.001 levels. The differences of AOD between years having  more and less rain/snow  are significant. Atmospheric AOD is clearly larger   in the years having more rain/snow, and the average of positive anomaly of AOD reaches 1×10-3-5×10-3 in the north of North China and the south of Northeast China. However, the difference relative to this value is significant in the years having less rain/snow. The atmospheric AOD shows  a significantly negative anomaly and the average is -5×10-3. Related Articles | Metrics