Volume 45,Issue 1,2017 Table of Contents
2017, 45(1):1-6.
Abstract:
A cloud particle measurement system is a key instrument to carry out the research on cloud precipitation physics and weather modification. In China, most of the instruments are currently imported from overseas. Not only the calibration of the instrument depends on the manufacturers abroad, and costs users’ large amount of money and time, but also the traditional glass bead calibration method has defects of easy adhesion and so on. Based on the present situation, a new calibration method is proposed, which utilizes the sophisticated inkjet printing technology and visual measurement techniques to produce controllable, stable continuous water droplets of 5 diameters (from 10 μm to 50 μm) for the calibration of the instruments. The prototype structure of the system is described in detail. The factors affecting the working performance of the system are analyzed. The same Cloud Droplet Probe (CDP) is calibrated, and the new method is compared with the traditional method. The results show that the method can meet the needs of calibration of the cloud particle measurement system, and the equipment performs well and is easy to control.
A cloud particle measurement system is a key instrument to carry out the research on cloud precipitation physics and weather modification. In China, most of the instruments are currently imported from overseas. Not only the calibration of the instrument depends on the manufacturers abroad, and costs users’ large amount of money and time, but also the traditional glass bead calibration method has defects of easy adhesion and so on. Based on the present situation, a new calibration method is proposed, which utilizes the sophisticated inkjet printing technology and visual measurement techniques to produce controllable, stable continuous water droplets of 5 diameters (from 10 μm to 50 μm) for the calibration of the instruments. The prototype structure of the system is described in detail. The factors affecting the working performance of the system are analyzed. The same Cloud Droplet Probe (CDP) is calibrated, and the new method is compared with the traditional method. The results show that the method can meet the needs of calibration of the cloud particle measurement system, and the equipment performs well and is easy to control.
2017, 45(1):7-14.
Abstract:
To explore the impact of urbanization on meteorological observation and its environment, taking the national climate stations of Shouxian (SX) as an example to investigate the influence of urbanization on land use/land cover (LULC), the thermal environment of the station and the temperature/wind and their relationships are studied by using the Landsat data along with GIS and meteorological data. Results show: (1) The urbanizationinduced LULC change is the main cause of influencing the representativeness of meteorological stations. (2) The urban construction land was the main factor affecting the spatial distribution of the thermal environment around these stations, and along with the propulsion of urbanization, the contribution to these stations of the urban construction land were constantly enlarged. While in low and sublow temperature zones, vegetation and water are the main contributors. (3) Take the new site as the reference station, the higher air temperature and lower wind speed are found at the old site than those at the new site, and the match rate for wind direction is only about 15%, influenced by the rapid urbanization of Shouxian. The effects of urban expansion on meteorological factors present significant diurnal and seasonal variations. Consequently, controlling the scale and layout of the urban construction land around the stations is an effective way to improve stations’ thermal environment and enhance region representativeness.
To explore the impact of urbanization on meteorological observation and its environment, taking the national climate stations of Shouxian (SX) as an example to investigate the influence of urbanization on land use/land cover (LULC), the thermal environment of the station and the temperature/wind and their relationships are studied by using the Landsat data along with GIS and meteorological data. Results show: (1) The urbanizationinduced LULC change is the main cause of influencing the representativeness of meteorological stations. (2) The urban construction land was the main factor affecting the spatial distribution of the thermal environment around these stations, and along with the propulsion of urbanization, the contribution to these stations of the urban construction land were constantly enlarged. While in low and sublow temperature zones, vegetation and water are the main contributors. (3) Take the new site as the reference station, the higher air temperature and lower wind speed are found at the old site than those at the new site, and the match rate for wind direction is only about 15%, influenced by the rapid urbanization of Shouxian. The effects of urban expansion on meteorological factors present significant diurnal and seasonal variations. Consequently, controlling the scale and layout of the urban construction land around the stations is an effective way to improve stations’ thermal environment and enhance region representativeness.
2017, 45(1):15-21.
Abstract:
In the 40872 regional automatic weather stations participating in information quality assessment, due to the initial information deviation of the position of station (POS), changed POS information, site demolition, and other reasons, the statements of POS information are inconsistent with the actual situation. It is necessary to inspect and found the abnormal stations so to improve the observation quality. Using the SQL index data query optimization and regular Chinese character matching technology, the altitudes and locations of the regional automatic weather stations are inspected, and the accuracy of POS’s is assessed. Statistical analysis indicates that the stations with altitude differrence within 20 m account for about 72%, those more than 100 m about 7%, those within 1 km about 62%, and those more than 10 km and no matching results about 6%. Study indicates that the most of the national regional automatic weather station POS data are accurate and applicable. The related management department should verify the abnormal changes of POS information, and the results of the evaluation can be used for finding the corresponding solution in operational applications.
In the 40872 regional automatic weather stations participating in information quality assessment, due to the initial information deviation of the position of station (POS), changed POS information, site demolition, and other reasons, the statements of POS information are inconsistent with the actual situation. It is necessary to inspect and found the abnormal stations so to improve the observation quality. Using the SQL index data query optimization and regular Chinese character matching technology, the altitudes and locations of the regional automatic weather stations are inspected, and the accuracy of POS’s is assessed. Statistical analysis indicates that the stations with altitude differrence within 20 m account for about 72%, those more than 100 m about 7%, those within 1 km about 62%, and those more than 10 km and no matching results about 6%. Study indicates that the most of the national regional automatic weather station POS data are accurate and applicable. The related management department should verify the abnormal changes of POS information, and the results of the evaluation can be used for finding the corresponding solution in operational applications.
2017, 45(1):22-29.
Abstract:
An analysis is made of the data from a comparative observation test for cloud height Indicators, which was carried out at the Beijing Meteorological Observatory from December 2011 to June 2012 The Sigma Space Micro Pulse Lidar (MPL) was used as a reference along with visual assessment. The observational data of different weather conditions are analyzed mainly from the aspects of false layers, missed layers, and layer height comparability, respectively, as well as high and low visibility. There is also an assessment towards the detection capability for several typical cloud genera. The results indicate that ceilometers are in good consistency with MPL; aerosol particles (fog, haze) in the atmosphere are the main cause of inaccurate measurements; the capability of ceilometers can be improved by increasing the single laser pulse energy and optimizing the optical system.
An analysis is made of the data from a comparative observation test for cloud height Indicators, which was carried out at the Beijing Meteorological Observatory from December 2011 to June 2012 The Sigma Space Micro Pulse Lidar (MPL) was used as a reference along with visual assessment. The observational data of different weather conditions are analyzed mainly from the aspects of false layers, missed layers, and layer height comparability, respectively, as well as high and low visibility. There is also an assessment towards the detection capability for several typical cloud genera. The results indicate that ceilometers are in good consistency with MPL; aerosol particles (fog, haze) in the atmosphere are the main cause of inaccurate measurements; the capability of ceilometers can be improved by increasing the single laser pulse energy and optimizing the optical system.
2017, 45(1):30-35.
Abstract:
The meteorological data is widely varied, massive, and complex, so it has made huge system pressure in the China Integrated Meteorological Information Service System (CIMISS). The design of database tables and the optimization of the process are analyzed in detail by the Lband upperair data as a case. The database redundancy is reduced by means of the "keyelement," reasonable index, and partition to improve database access efficiency, through simple procedure to reduce the message interaction between the system and IO, so as to optimize the storage efficiency. Comparison of the storage methods OCI and PRO*C shows that PRO*C is easy to develop, and OCI has comprehensive functions but relatively complex. By comparing the efficiency of two storage modes, the system takes a PRO*C way. The actual running effect of Lband data shows that to complete a data processing takes an average of 28 s. Compared with the sounding data, the simple procedure performs faster, compared to the original.
The meteorological data is widely varied, massive, and complex, so it has made huge system pressure in the China Integrated Meteorological Information Service System (CIMISS). The design of database tables and the optimization of the process are analyzed in detail by the Lband upperair data as a case. The database redundancy is reduced by means of the "keyelement," reasonable index, and partition to improve database access efficiency, through simple procedure to reduce the message interaction between the system and IO, so as to optimize the storage efficiency. Comparison of the storage methods OCI and PRO*C shows that PRO*C is easy to develop, and OCI has comprehensive functions but relatively complex. By comparing the efficiency of two storage modes, the system takes a PRO*C way. The actual running effect of Lband data shows that to complete a data processing takes an average of 28 s. Compared with the sounding data, the simple procedure performs faster, compared to the original.
2017, 45(1):36-41.
Abstract:
A method for reading NC files for the interface based on C # and Matlab mixed programming is introduced. The Matlab toolbox library of NC files is used to write Mfile for the corresponding method, and then the Mfile is compiled into a DLL class library, and the DLL library is called in order to achieve the overall function, using C# as the development platform for the interface. An case of the WebService interface is written to extract any point or free clipping of NC files. The feasibility of this method is verified while the interface can be quickly called.
A method for reading NC files for the interface based on C # and Matlab mixed programming is introduced. The Matlab toolbox library of NC files is used to write Mfile for the corresponding method, and then the Mfile is compiled into a DLL class library, and the DLL library is called in order to achieve the overall function, using C# as the development platform for the interface. An case of the WebService interface is written to extract any point or free clipping of NC files. The feasibility of this method is verified while the interface can be quickly called.
2017, 45(1):42-46.
Abstract:
Level 1 remote sensing data of polar meteorological satellite are the basis of quantitative application of remote sensing information, which can ensure the data quality at the most extent when the abnormal phenomenon of affecting the integrity and timeliness of level1 remote sensing data is known, and the abnormal problem is located and solved as fast as possible. Taking the FY3B satellite as an example, with the operating experiences accumulated by the National Satellite Meteorological Center for many years, the quality problems of FY3B are classified, and then some quality assurance technologies are studied, aiming at problematic phenomena, reason locations, and solutions. The findings provide proposals for the ground application system to further improve the quality of level1 data.
Level 1 remote sensing data of polar meteorological satellite are the basis of quantitative application of remote sensing information, which can ensure the data quality at the most extent when the abnormal phenomenon of affecting the integrity and timeliness of level1 remote sensing data is known, and the abnormal problem is located and solved as fast as possible. Taking the FY3B satellite as an example, with the operating experiences accumulated by the National Satellite Meteorological Center for many years, the quality problems of FY3B are classified, and then some quality assurance technologies are studied, aiming at problematic phenomena, reason locations, and solutions. The findings provide proposals for the ground application system to further improve the quality of level1 data.
2017, 45(1):47-51.
Abstract:
A method for recognizing and automatically processing rainfall records resulted from snow melting from regional automatic observation stations in winter is introduced in detail. The recognition is divided into two processes: snowfall and snowmelt. Under the premise of snowfall, the selected station has a record of rainfall, and it is in accordance with the condition of melting snow. According to the inspection, the automatic recognition accuracy rate is as high as 90%. The temperature of regional automatic observation stations is used as the main condition of snowfall and snow melting, combined with the data of national meteorological observation stations and the comprehensive judgment. In order to improve the recognition of weather conditions and the nature of precipitation, the radarestimated precipitation, winter precipitation phase discrimination, and other products are also added to make up for the defects of a single reference station for precipitation data, which is of significance to the recognition of snowmelt and rainfall records.
A method for recognizing and automatically processing rainfall records resulted from snow melting from regional automatic observation stations in winter is introduced in detail. The recognition is divided into two processes: snowfall and snowmelt. Under the premise of snowfall, the selected station has a record of rainfall, and it is in accordance with the condition of melting snow. According to the inspection, the automatic recognition accuracy rate is as high as 90%. The temperature of regional automatic observation stations is used as the main condition of snowfall and snow melting, combined with the data of national meteorological observation stations and the comprehensive judgment. In order to improve the recognition of weather conditions and the nature of precipitation, the radarestimated precipitation, winter precipitation phase discrimination, and other products are also added to make up for the defects of a single reference station for precipitation data, which is of significance to the recognition of snowmelt and rainfall records.
2017, 45(1):52-58.
Abstract:
The high resolution numerical weather prediction system in Central China, named WuHan Mesoscale Model (WHMM), is designed and operated since 1 April 2014 This operational system was submitted and ran by the command lines. There are still some shortcomings in WHMM, such as, monitoring and managing the system not intuitively enough, finding and processing obstacles not conveniently, and having low operational efficiency. Therefore, the new WHMM with the client/server architecture is designed based on the Supervisor Monitor Scheduler (SMS). The new operational system fully considers the relationship between processes and the integrating all processes as a whole. Compared with the original system, it has the following characteristics: providing a clear and friend graphical interface and monitoring conveniently； locating and solving the obstacles easily and quickly. Additionally， it could improve greatly the operational efficiency, and the overall running time decreased about 354%, which is mainly concentrated in the downloading data, postprocessing, and making products.
The high resolution numerical weather prediction system in Central China, named WuHan Mesoscale Model (WHMM), is designed and operated since 1 April 2014 This operational system was submitted and ran by the command lines. There are still some shortcomings in WHMM, such as, monitoring and managing the system not intuitively enough, finding and processing obstacles not conveniently, and having low operational efficiency. Therefore, the new WHMM with the client/server architecture is designed based on the Supervisor Monitor Scheduler (SMS). The new operational system fully considers the relationship between processes and the integrating all processes as a whole. Compared with the original system, it has the following characteristics: providing a clear and friend graphical interface and monitoring conveniently； locating and solving the obstacles easily and quickly. Additionally， it could improve greatly the operational efficiency, and the overall running time decreased about 354%, which is mainly concentrated in the downloading data, postprocessing, and making products.
2017, 45(1):59-63.
Abstract:
Using virtual simulation technology and the GaeaExplorer 3DGIS platform, the 3D visual and analysis system of lightning data is designed and developed, which constructs the spatial database and the 3D simulate scene and realizes the fine 3D visualization of lightning data for the first time. By means of the spatial analysis capability of GIS, this system develops the function of data management and spatial analysis. It is important for lightning risk reduction and decision service to provide 3D data. The result shows that the system can provide a good application experience and make a solid foundation for lightning detection and scientific researches.
Using virtual simulation technology and the GaeaExplorer 3DGIS platform, the 3D visual and analysis system of lightning data is designed and developed, which constructs the spatial database and the 3D simulate scene and realizes the fine 3D visualization of lightning data for the first time. By means of the spatial analysis capability of GIS, this system develops the function of data management and spatial analysis. It is important for lightning risk reduction and decision service to provide 3D data. The result shows that the system can provide a good application experience and make a solid foundation for lightning detection and scientific researches.
2017, 45(1):64-67.
Abstract:
The remote video monitoring system for new generation weather radar is developed to meet the requirements of weather radar guarantee service. The system has realized the functions of video capture, remote assistance, data acquisition, and state monitoring. The system can quickly identify faults, while taking advantage of the remote assistance, and experts can constitutes the maintenance schema and improve radar guarantee timeliness. At present, the system has been successfully applied to four radar stations to meet the needs of remote fault diagnosis visualization and is used to improve radar operational support capabilities.
The remote video monitoring system for new generation weather radar is developed to meet the requirements of weather radar guarantee service. The system has realized the functions of video capture, remote assistance, data acquisition, and state monitoring. The system can quickly identify faults, while taking advantage of the remote assistance, and experts can constitutes the maintenance schema and improve radar guarantee timeliness. At present, the system has been successfully applied to four radar stations to meet the needs of remote fault diagnosis visualization and is used to improve radar operational support capabilities.
2017, 45(1):68-71.
Abstract:
For the difficult fault cases of the test signal abnormality of CINRAD/CD, concepts and methods for standardized maintenance of large electronic equipment are introduced. In combination with the principles and signal processing of the radar system, The fault diagnosis methods such as principle analysis, leapfrog, measurement, substitution, and so on, are used to analyze and judge faults, gradually narrowing the scope of troubleshooting. The root cause of the fault is a broken signal line between receiver and monitor unit, resulting in that the control codes cannot be send to SPDT switch in the microwave module. The standardized maintenance procedures about the type of faults are proposed, and the methods and ideas of the fault diagnosis can be used as a reference in CINRAD technical support work.
For the difficult fault cases of the test signal abnormality of CINRAD/CD, concepts and methods for standardized maintenance of large electronic equipment are introduced. In combination with the principles and signal processing of the radar system, The fault diagnosis methods such as principle analysis, leapfrog, measurement, substitution, and so on, are used to analyze and judge faults, gradually narrowing the scope of troubleshooting. The root cause of the fault is a broken signal line between receiver and monitor unit, resulting in that the control codes cannot be send to SPDT switch in the microwave module. The standardized maintenance procedures about the type of faults are proposed, and the methods and ideas of the fault diagnosis can be used as a reference in CINRAD technical support work.
2017, 45(1):72-78.
Abstract:
Based on the NCAR/NCEP daily reanalysis data of 500 hPa in the Northern Hemisphere since 1960, a dynamic similarity ensemblemean method is adopted to perform extendedrange weather forecast tests in Chongqing. Specifically, the Empirical Orthogonal Functions (EOF) method is used to extract and reconstruct the principle spatial patterns of the geopotential height during the previous few months. Within the domain of interest, candidate years with the greatest similarities are confirmed by comparing the constructed circulation patterns in each year via an analogous precursor method. After altering the temporal length of the early data, the method is conducted again to determine five typical years. In the target area, the daily precipitation frequency is then accumulated in these five years, and further presented by curves. By tracing the peaks and valleys of the curves, the date of regional heavy precipitation can be successfully forecasted in the extended range. Forecast tests indicate that results derived by this method can provide some reference for extendedrange forecasts of precipitation and temperature drop in Chongqing.
Based on the NCAR/NCEP daily reanalysis data of 500 hPa in the Northern Hemisphere since 1960, a dynamic similarity ensemblemean method is adopted to perform extendedrange weather forecast tests in Chongqing. Specifically, the Empirical Orthogonal Functions (EOF) method is used to extract and reconstruct the principle spatial patterns of the geopotential height during the previous few months. Within the domain of interest, candidate years with the greatest similarities are confirmed by comparing the constructed circulation patterns in each year via an analogous precursor method. After altering the temporal length of the early data, the method is conducted again to determine five typical years. In the target area, the daily precipitation frequency is then accumulated in these five years, and further presented by curves. By tracing the peaks and valleys of the curves, the date of regional heavy precipitation can be successfully forecasted in the extended range. Forecast tests indicate that results derived by this method can provide some reference for extendedrange forecasts of precipitation and temperature drop in Chongqing.
2017, 45(1):79-86.
Abstract:
The observed outgoing longwave radiation (OLR) from NOAA and variables of 〖WTBX〗q,T,u,v,ω 〖WTBZ〗from ERAInterim daily data set in 2002 and 2003 are analyzed by a new method of interaction among multiple timescale components to reveal the process of moisture increasing in the boundary layer before the initiation of two MJO convective events (MJO1 and MJO2, happening in the winter of 2002). It is found that during 3 days before the two MJO convections initiated, there are the 20-90 day filtered positive moisture tendency, positive moisture anomaly and vertical ascending motion leading the MJO1 and MJO2 convections in boundary layer, which indicates that moisture increasing in the boundary layer creates the convectively unstable layer good to the initiation of MJO convections. Positive horizontal moisture advection is the main contributor to the moisture increasing in both MJO1 and MJO2, which contributed to the advection process in which intraseasonal easterly transports the larger mean background moisture to the two initiation regions. The greatest difference in the process of moisture increasing between MJO1 and MJO2 is the positive vertical moisture convection, which is much larger in MJO2 than that in MJO1, which mainly contributed to the distinct difference of the component of mean background moisture by intraseasonal vertical ascending motion between MJO1 and MJO2, because there is a larger ascending motion of 20 to 90 day time scale in MJO2 than that in MJO1
The observed outgoing longwave radiation (OLR) from NOAA and variables of 〖WTBX〗q,T,u,v,ω 〖WTBZ〗from ERAInterim daily data set in 2002 and 2003 are analyzed by a new method of interaction among multiple timescale components to reveal the process of moisture increasing in the boundary layer before the initiation of two MJO convective events (MJO1 and MJO2, happening in the winter of 2002). It is found that during 3 days before the two MJO convections initiated, there are the 20-90 day filtered positive moisture tendency, positive moisture anomaly and vertical ascending motion leading the MJO1 and MJO2 convections in boundary layer, which indicates that moisture increasing in the boundary layer creates the convectively unstable layer good to the initiation of MJO convections. Positive horizontal moisture advection is the main contributor to the moisture increasing in both MJO1 and MJO2, which contributed to the advection process in which intraseasonal easterly transports the larger mean background moisture to the two initiation regions. The greatest difference in the process of moisture increasing between MJO1 and MJO2 is the positive vertical moisture convection, which is much larger in MJO2 than that in MJO1, which mainly contributed to the distinct difference of the component of mean background moisture by intraseasonal vertical ascending motion between MJO1 and MJO2, because there is a larger ascending motion of 20 to 90 day time scale in MJO2 than that in MJO1
15 Calculation and Contrastive Analysis of Rainstorm Intensity Formula for Main Urban Areas of Kunming
2017, 45(1):87-91.
Abstract:
Using the minutely precipitation data of the Kunming national basic climate station from 1981 to 2014, the rainstrom formula fitted by Pearson Ⅲ distribution, Gumbell distribution, and exponential distribution are worked out respectively by the annual maximum value method. Tested by accuracy, based on the principles of minimum error，the formula fitted by the Gumbell distribution proved optimal. Contrasting the newly formulated formula with the five rainstorm intensity formula formulated respectively for Kunming and analyzing the spatial and temporal distribution features of rainstorm intensity in Kunming, the formula proved reasonable and applicable, which can provide the basis and reference for Kunming flood control engineering design and construction.
Using the minutely precipitation data of the Kunming national basic climate station from 1981 to 2014, the rainstrom formula fitted by Pearson Ⅲ distribution, Gumbell distribution, and exponential distribution are worked out respectively by the annual maximum value method. Tested by accuracy, based on the principles of minimum error，the formula fitted by the Gumbell distribution proved optimal. Contrasting the newly formulated formula with the five rainstorm intensity formula formulated respectively for Kunming and analyzing the spatial and temporal distribution features of rainstorm intensity in Kunming, the formula proved reasonable and applicable, which can provide the basis and reference for Kunming flood control engineering design and construction.
16 Characteristics of Extreme Precipitation and Its MultiModel Simulation Evaluation in North China
2017, 45(1):92-101.
Abstract:
Based on the daily precipitation from observation stations in North China from 1961 to 2010, six extreme precipitation indexes are calculated and their spatial and temporal variation characteristics are analyzed. The simulated capability of global climate models which from CMIP5 on the extreme precipitation are further evaluated. The results are as follows: （1）The extreme precipitation indexes in North China show large regional differences. The values are high in south and low in north of North China for precipitation intensity and extreme precipitation thresholds. The rain days and continuous dry days are different between east and west of North China. The interannual variability of extreme precipitation indexes has a drying trend, and the intensity of extreme events is increasing at the same time. （2）There are differences between the global climate models of CMIP5 for simulating North China extreme precipitation index. The spatial distribution of precipitation intensity and extreme precipitation threshold have a better performance in the models. The pattern correlation coefficients are above 06 for more than half models. The same model has different simulated capabilities for different extreme precipitation indexes. （3） The pattern correlation coefficient and root mean square error have good consistency, and the correlation coefficient of model ranking is larger than 04 HadGEM2CC，HadGEM2ES，MIROC4h，MIROC5, and CCSM4 are the best five global models. Compared to allmodal ensemble average, the bestmodel ensemble average can significantly reduce the wet deviation of simulation.
Based on the daily precipitation from observation stations in North China from 1961 to 2010, six extreme precipitation indexes are calculated and their spatial and temporal variation characteristics are analyzed. The simulated capability of global climate models which from CMIP5 on the extreme precipitation are further evaluated. The results are as follows: （1）The extreme precipitation indexes in North China show large regional differences. The values are high in south and low in north of North China for precipitation intensity and extreme precipitation thresholds. The rain days and continuous dry days are different between east and west of North China. The interannual variability of extreme precipitation indexes has a drying trend, and the intensity of extreme events is increasing at the same time. （2）There are differences between the global climate models of CMIP5 for simulating North China extreme precipitation index. The spatial distribution of precipitation intensity and extreme precipitation threshold have a better performance in the models. The pattern correlation coefficients are above 06 for more than half models. The same model has different simulated capabilities for different extreme precipitation indexes. （3） The pattern correlation coefficient and root mean square error have good consistency, and the correlation coefficient of model ranking is larger than 04 HadGEM2CC，HadGEM2ES，MIROC4h，MIROC5, and CCSM4 are the best five global models. Compared to allmodal ensemble average, the bestmodel ensemble average can significantly reduce the wet deviation of simulation.
2017, 45(1):102-107.
Abstract:
The climate characteristics of dense fogs and the anomalous circulation characteristics and atmospheric circulation patterns of autumn dense fogs since 2000 in Heilongjiang Province are discussed. This research shows that dense fog days appear mostly in summer in mountain areas. The dense fog events causing severe disasters with wide range and long duration occur most frequently in autumn. All the persistent dense fog weather events in October and November are after 2010 Most of the dense fog days occur under the warm and the moist background in autumn. Based on the 500 hPa mean height and anomaly fields, the major atmospheric circulation patterns, the lower height in west and the higher height in east and the zonal circulations are put forward. Anomalous circulation characteristics such as the big positive height anomaly at middle and lower levels, anticyclone circulation at 850 hPa, and the strong norththannormal Northwest Pacific Subtropical High are helpful to improve the quality of fog forecast in the medium and short term in Heilongjiang Province.
The climate characteristics of dense fogs and the anomalous circulation characteristics and atmospheric circulation patterns of autumn dense fogs since 2000 in Heilongjiang Province are discussed. This research shows that dense fog days appear mostly in summer in mountain areas. The dense fog events causing severe disasters with wide range and long duration occur most frequently in autumn. All the persistent dense fog weather events in October and November are after 2010 Most of the dense fog days occur under the warm and the moist background in autumn. Based on the 500 hPa mean height and anomaly fields, the major atmospheric circulation patterns, the lower height in west and the higher height in east and the zonal circulations are put forward. Anomalous circulation characteristics such as the big positive height anomaly at middle and lower levels, anticyclone circulation at 850 hPa, and the strong norththannormal Northwest Pacific Subtropical High are helpful to improve the quality of fog forecast in the medium and short term in Heilongjiang Province.
2017, 45(1):108-115.
Abstract:
The changing trends of temperature and precipitation for the 21st century over Guizhou under RCPs scenarios are analyzed using the multimodel dataset of World Climate Research Programme’s Coupled Model Intercomparison Project phase 5 The results show a relatively good (poor) performance of temperature (precipitation) simulation in Guizhou based on the normalized root mean square error (NRMSE). It is found that the projected temperature (precipitation) shows a warmer (wetter) trend of 05 ℃/10a (10%/10a), 02 ℃/10a (09%/10), and 01 ℃/10a (06%/10a), respectively, in Guizhou under the scenarios of RCP85, RCP45, and RCP26, with an increase of 45 ℃ (52%), 23 ℃ (54%), and 13 ℃ (42%) relative to the reference period in the end of the 21st century. From the perspective of the spatial distribution, the increase of annual temperature relative to the reference period at the end of the 21st century gradually grows up from southwest to northeast, while precipitation has different change for different scenarios and areas. Overall, the higher the greenhouse gas concentration in the 21st century, the faster the rate of warming and wetting.
The changing trends of temperature and precipitation for the 21st century over Guizhou under RCPs scenarios are analyzed using the multimodel dataset of World Climate Research Programme’s Coupled Model Intercomparison Project phase 5 The results show a relatively good (poor) performance of temperature (precipitation) simulation in Guizhou based on the normalized root mean square error (NRMSE). It is found that the projected temperature (precipitation) shows a warmer (wetter) trend of 05 ℃/10a (10%/10a), 02 ℃/10a (09%/10), and 01 ℃/10a (06%/10a), respectively, in Guizhou under the scenarios of RCP85, RCP45, and RCP26, with an increase of 45 ℃ (52%), 23 ℃ (54%), and 13 ℃ (42%) relative to the reference period in the end of the 21st century. From the perspective of the spatial distribution, the increase of annual temperature relative to the reference period at the end of the 21st century gradually grows up from southwest to northeast, while precipitation has different change for different scenarios and areas. Overall, the higher the greenhouse gas concentration in the 21st century, the faster the rate of warming and wetting.
2017, 45(1):116-121.
Abstract:
Based on the observation data of frozen soil from 61 meteorological stations in Liaoning Province from 1964 to 2013, by using methods of linear regression, correlation analysis, and comparison of different standard climate periods, the spatial and temporal variations of frozen soil are investigated. The seasonal change of frozen soil, changes of frozen soil depth, beginning dates, and ending dates are analyzed. The results show that frozen soil in Liaoning Province are distributed zonally with latitude; the seasonal variation of frozen soil is significant, freezing appears mainly in October to next May and the freezing area and depth reach the maximum in late winter and early spring; freezing dates gradually postpone from north to South; thawing date and freezing date are just the opposite. Under the background of global warming in the last few decades, the frozen soil shows a degradation in Liaoning. In most areas the annual average temperature and the surface temperature are significantly negatively correlated with the maximum frozen soil depth, which are the most important factors affecting the depth of frozen soil. The maximum depth of frozen soil shows a shallow trend according to the 100cm isobath for different climate periods.
Based on the observation data of frozen soil from 61 meteorological stations in Liaoning Province from 1964 to 2013, by using methods of linear regression, correlation analysis, and comparison of different standard climate periods, the spatial and temporal variations of frozen soil are investigated. The seasonal change of frozen soil, changes of frozen soil depth, beginning dates, and ending dates are analyzed. The results show that frozen soil in Liaoning Province are distributed zonally with latitude; the seasonal variation of frozen soil is significant, freezing appears mainly in October to next May and the freezing area and depth reach the maximum in late winter and early spring; freezing dates gradually postpone from north to South; thawing date and freezing date are just the opposite. Under the background of global warming in the last few decades, the frozen soil shows a degradation in Liaoning. In most areas the annual average temperature and the surface temperature are significantly negatively correlated with the maximum frozen soil depth, which are the most important factors affecting the depth of frozen soil. The maximum depth of frozen soil shows a shallow trend according to the 100cm isobath for different climate periods.
2017, 45(1):122-130.
Abstract:
Using the NCEP/NCAR reanalysis data (1°×1°) and the daily precipitation data of 15 weather stations and 200 regional automatic stations over the western South Xinjiang (35° to 42°N, 73° to 80°E) in 2013, the source region, transportation, and budget features of the water vapor associated with four typical rainstorm processes over the region are analyzed. The results show that in these processes, where a strong lowlevel easterly jet (LLEJ) played a significant role, the vapor sources mainly were the Arabian Sea and the Bay of Bengal, followed by the Persian Gulf. In Process 1, the vapor was mainly transported via the easterly and southwesterly. The strong convergence over the mountains in the west and the plain in the east of South Xinjiang triggered the rainstorm. The vapor transportation with high value lasted for 24 hours, was lager in the easterly path than the southwesterly one. In Process 2, there were three paths of vapor transportation: westerly, southwesterly, and easterly, which all generated severe convergence over the western South Xinjiang and induced the extensive and strong rainstorm. The vapor input of the easterly boundary was close to that of the southerly one. The vapor transportation of high value lasted for 60 hours. In Process 3, the vapor transportation was along the westerly, southerly and easterly path. The vapor led by LLEJ, under the intersection of the westerly and easterly, heaped up along the mountains, producing the strong convergence and the rainstorm. The vapor transportation of high value lasted for 24 hours. In Process 4, the vapor transportation was mainly along the westerly, southerly, and easterly paths. The vapor input of the westerly was much larger than that of the easterly and southerly. There appeared for 2 times that the highvalue vapor transportation areas of lower and upper levels were superposed, during which the area with highvalue vapor lasted for 48 hours.
Using the NCEP/NCAR reanalysis data (1°×1°) and the daily precipitation data of 15 weather stations and 200 regional automatic stations over the western South Xinjiang (35° to 42°N, 73° to 80°E) in 2013, the source region, transportation, and budget features of the water vapor associated with four typical rainstorm processes over the region are analyzed. The results show that in these processes, where a strong lowlevel easterly jet (LLEJ) played a significant role, the vapor sources mainly were the Arabian Sea and the Bay of Bengal, followed by the Persian Gulf. In Process 1, the vapor was mainly transported via the easterly and southwesterly. The strong convergence over the mountains in the west and the plain in the east of South Xinjiang triggered the rainstorm. The vapor transportation with high value lasted for 24 hours, was lager in the easterly path than the southwesterly one. In Process 2, there were three paths of vapor transportation: westerly, southwesterly, and easterly, which all generated severe convergence over the western South Xinjiang and induced the extensive and strong rainstorm. The vapor input of the easterly boundary was close to that of the southerly one. The vapor transportation of high value lasted for 60 hours. In Process 3, the vapor transportation was along the westerly, southerly and easterly path. The vapor led by LLEJ, under the intersection of the westerly and easterly, heaped up along the mountains, producing the strong convergence and the rainstorm. The vapor transportation of high value lasted for 24 hours. In Process 4, the vapor transportation was mainly along the westerly, southerly, and easterly paths. The vapor input of the westerly was much larger than that of the easterly and southerly. There appeared for 2 times that the highvalue vapor transportation areas of lower and upper levels were superposed, during which the area with highvalue vapor lasted for 48 hours.
2017, 45(1):131-139.
Abstract:
Using daily precipitation data, conventional data, sea surface temperature data, and NCEP/ NCAR reanalysis data from 2000 to 2013, the characteristics and causality of cold airflow snowfall in the Laizhou Bay are analyzed. The results show that the snowfall intensity is small, and the moderate and heavy snow are mainly concentrated in the eastern region of the Laizhou Bay. Duration of snowfall is short within 12 hours. Coldairflow snowfall happens more frequently in the east and less in the west of the Laizhou Bay and their interannual variation are obvious. Marked periodic variation of 6 to 7 years is found. Coldairflow snowfall often occurs in January, especially from the last tenday of December to the first tenday of January and mainly around 08:00 in the morning. There is a positive correlation between the annual cold air activity index and the number of cold airflow snowfall events. There are obvious temperature thresholds at <850 hPa levels during coldairflow snowfall events. Coldairflow snowfall happens less at too high or too low sea surface temperature and airsea temperature difference over the Laizhou Bay, and the ground temperature threshold (at 2 m) is below 5 ℃, which is higher than the inland snowfall threshold. Coldairflow snowfall often happens in the northwest airflow behind a trough (including behind eddy) at 500 hPa and the northwest winds at 700 hPa and 850 hPa, and there exist three circumfluence situations: northwest, north, and northeast winds at 925 hPa and 1000 hPa.
Using daily precipitation data, conventional data, sea surface temperature data, and NCEP/ NCAR reanalysis data from 2000 to 2013, the characteristics and causality of cold airflow snowfall in the Laizhou Bay are analyzed. The results show that the snowfall intensity is small, and the moderate and heavy snow are mainly concentrated in the eastern region of the Laizhou Bay. Duration of snowfall is short within 12 hours. Coldairflow snowfall happens more frequently in the east and less in the west of the Laizhou Bay and their interannual variation are obvious. Marked periodic variation of 6 to 7 years is found. Coldairflow snowfall often occurs in January, especially from the last tenday of December to the first tenday of January and mainly around 08:00 in the morning. There is a positive correlation between the annual cold air activity index and the number of cold airflow snowfall events. There are obvious temperature thresholds at <850 hPa levels during coldairflow snowfall events. Coldairflow snowfall happens less at too high or too low sea surface temperature and airsea temperature difference over the Laizhou Bay, and the ground temperature threshold (at 2 m) is below 5 ℃, which is higher than the inland snowfall threshold. Coldairflow snowfall often happens in the northwest airflow behind a trough (including behind eddy) at 500 hPa and the northwest winds at 700 hPa and 850 hPa, and there exist three circumfluence situations: northwest, north, and northeast winds at 925 hPa and 1000 hPa.
2017, 45(1):140-148.
Abstract:
Based on the FNL 1°×1° reanalysis data，the causes of the rainstorm process occurred on 3 and 4 July 2012 in Qinba Mountain in the southern Shaanxi Province are analyzed, and the rainstorm is simulated by using the mesoscale model WRFV331, focused on the influence of topography on this rainstorm process. It is showed that the main affecting systems include a plateau trough at 500 hPa, a vortex shear line at 700 and 850 hPa, the southwest airflow along the northwest side of Subtropical High. The southwest jet from Yungui Plateau to the southern Shaanxi Province at 700 hPa climbed in the southern region of Qinling Mountains, and converged with the easterly wind, which maintained and developed the low vortex with shear line. The vertical motion caused by the superposition of convergence and the climbing increased precipitation in the south slope of Qinling Mountains. The orographic effect of Qinba Mountain increased the precipitation in the mountain area. The cold air in back of the Plateau trough entered Qinling Mountains from north to south, and warm air transported from the southern Qinling Mountains formed the baroclinic front zone. The convergence and uplift of the lower atmosphere caused by topography strengthened the frontogenesis and the baroclinic instability. The analysis of cloud hydrometeors indicates that during heavy rainfall, the maximum value centers of cloud water, rain, and ice in vertical direction overlapped, in favor of the seedingsupply effect, which increased rain particles and precipitation in mountainous regions.
Based on the FNL 1°×1° reanalysis data，the causes of the rainstorm process occurred on 3 and 4 July 2012 in Qinba Mountain in the southern Shaanxi Province are analyzed, and the rainstorm is simulated by using the mesoscale model WRFV331, focused on the influence of topography on this rainstorm process. It is showed that the main affecting systems include a plateau trough at 500 hPa, a vortex shear line at 700 and 850 hPa, the southwest airflow along the northwest side of Subtropical High. The southwest jet from Yungui Plateau to the southern Shaanxi Province at 700 hPa climbed in the southern region of Qinling Mountains, and converged with the easterly wind, which maintained and developed the low vortex with shear line. The vertical motion caused by the superposition of convergence and the climbing increased precipitation in the south slope of Qinling Mountains. The orographic effect of Qinba Mountain increased the precipitation in the mountain area. The cold air in back of the Plateau trough entered Qinling Mountains from north to south, and warm air transported from the southern Qinling Mountains formed the baroclinic front zone. The convergence and uplift of the lower atmosphere caused by topography strengthened the frontogenesis and the baroclinic instability. The analysis of cloud hydrometeors indicates that during heavy rainfall, the maximum value centers of cloud water, rain, and ice in vertical direction overlapped, in favor of the seedingsupply effect, which increased rain particles and precipitation in mountainous regions.
2017, 45(1):149-157.
Abstract:
Utilizing the conventional meteorological data, NECP 1°×1° reanalysis data, surface precipitation and Fujian CINRAD/SA data, the cause of the heavy rainfall over the western Fujian Province after Saola Typhoon landing is analyzed. The results show that the northerly flow of Continental High Pressure led to the southward movement of Saola’s upper vortex. When the typhoon entered the large environmental vertical wind shear zone, the typhoon tilted to the left of the shearline, which made typhoon move more southward. The south tilting structure provided favorable dynamic condition over heavy rainfall region. The water vapor transportation supplied by Typhoon Saola and the typhoon’s southwest airflow provided sufficient moisture for the heavy rainfall. The cold air intrusion at upper levels and warm and moist air at low levels induced the conditional instability, which was favorable for the development of deep wet convection. Warm advection combined with velocity convergence, the incursion of dry cold air at upper level, warm and moist air at low levels, and the establishment of the southwest jet at lower levels were three mesoscale systems favorable for the severe rain.
Utilizing the conventional meteorological data, NECP 1°×1° reanalysis data, surface precipitation and Fujian CINRAD/SA data, the cause of the heavy rainfall over the western Fujian Province after Saola Typhoon landing is analyzed. The results show that the northerly flow of Continental High Pressure led to the southward movement of Saola’s upper vortex. When the typhoon entered the large environmental vertical wind shear zone, the typhoon tilted to the left of the shearline, which made typhoon move more southward. The south tilting structure provided favorable dynamic condition over heavy rainfall region. The water vapor transportation supplied by Typhoon Saola and the typhoon’s southwest airflow provided sufficient moisture for the heavy rainfall. The cold air intrusion at upper levels and warm and moist air at low levels induced the conditional instability, which was favorable for the development of deep wet convection. Warm advection combined with velocity convergence, the incursion of dry cold air at upper level, warm and moist air at low levels, and the establishment of the southwest jet at lower levels were three mesoscale systems favorable for the severe rain.
2017, 45(1):158-164.
Abstract:
By using the 1949-2014 “Typhoon Annuals” compiled by the Shanghai Typhoon Institute, conventional precipitation, wind, and daily mean NCEP (25°×25°) reanalysis data, all extratropical transitional typhoons affecting Shandong are found and their spatialtemporal distributive climatic characteristics are analyzed.The results show that: from 1949 to 2014, there are 80 extratropical transitional typhoons affected Shandong. Typhoon transition occurs mainly in the middle latitudes. The number of extratropical transitional typhoons has obvious interdecadal variation and annual variation. The transitional typhoons mainly appear in summer and autumn, and relatively rare in spring and winter. The location of typhoon transition is related to the subtropical high and middle latitude westerly trough. There are obvious front areas when typhoons transit, and the intensity of the front zones is positively related to the number of the transitional typhoons. There are 33 typhoons transited and enhanced, in which the baroclinic frontal zone, cold air, cold air inclining from the middle and upper levels and sinking, upperlevel positive vorticity advection, and lowlevel warm advection are important factors beneficial to the strengthening of transitional typhoons.
By using the 1949-2014 “Typhoon Annuals” compiled by the Shanghai Typhoon Institute, conventional precipitation, wind, and daily mean NCEP (25°×25°) reanalysis data, all extratropical transitional typhoons affecting Shandong are found and their spatialtemporal distributive climatic characteristics are analyzed.The results show that: from 1949 to 2014, there are 80 extratropical transitional typhoons affected Shandong. Typhoon transition occurs mainly in the middle latitudes. The number of extratropical transitional typhoons has obvious interdecadal variation and annual variation. The transitional typhoons mainly appear in summer and autumn, and relatively rare in spring and winter. The location of typhoon transition is related to the subtropical high and middle latitude westerly trough. There are obvious front areas when typhoons transit, and the intensity of the front zones is positively related to the number of the transitional typhoons. There are 33 typhoons transited and enhanced, in which the baroclinic frontal zone, cold air, cold air inclining from the middle and upper levels and sinking, upperlevel positive vorticity advection, and lowlevel warm advection are important factors beneficial to the strengthening of transitional typhoons.
2017, 45(1):165-171.
Abstract:
Based on the WRF (Weather Research and Forecast) model and T639 data as the initial and boundary conditions, a fog process in Jinan from 13 to 14 in November 2015 is simulated. The result of simulation test is verified by the routine meteorological observation data, and the causation of the fog is analyzed from four respects. The results show: (1) the stable atmospheric layer, gentle wind, small difference between temperature and dew point are the favorite conditions for the formation of fog; (2) the occurrence and development of the fog as well as the intensity of visibility can be simulated by the WRF model; (3) the maintenance of the neutral layer and enough moisture play the key part for the formation and development of the fog; the low clouds have effect on the formation of the neutral layers near the ground and postpones the dissipation of the fog in the daytime; (4) during the formation and development of the fog, the convergence ascending motion below 925 hPa and divergence sinking motion above 925 hPa can be favorable to the formation of the fog by making the moisture accumulate in the surface layers; (5) the cold advection can be beneficial to the fog formation by increasing relative humidity, while the advection below 850 hPa get warmer in the dissipation phase of the fog, the nonadiabatic factor have little impact on the formation and development of the fog.
Based on the WRF (Weather Research and Forecast) model and T639 data as the initial and boundary conditions, a fog process in Jinan from 13 to 14 in November 2015 is simulated. The result of simulation test is verified by the routine meteorological observation data, and the causation of the fog is analyzed from four respects. The results show: (1) the stable atmospheric layer, gentle wind, small difference between temperature and dew point are the favorite conditions for the formation of fog; (2) the occurrence and development of the fog as well as the intensity of visibility can be simulated by the WRF model; (3) the maintenance of the neutral layer and enough moisture play the key part for the formation and development of the fog; the low clouds have effect on the formation of the neutral layers near the ground and postpones the dissipation of the fog in the daytime; (4) during the formation and development of the fog, the convergence ascending motion below 925 hPa and divergence sinking motion above 925 hPa can be favorable to the formation of the fog by making the moisture accumulate in the surface layers; (5) the cold advection can be beneficial to the fog formation by increasing relative humidity, while the advection below 850 hPa get warmer in the dissipation phase of the fog, the nonadiabatic factor have little impact on the formation and development of the fog.
2017, 45(1):172-178.
Abstract:
Based on conventional observational data, NECP 1°×1° reanalysis data, and Lband sounding second data, two fog and haze cases occurred in 2013 are analyzed,including the circulation situation, diffusion conditions, and boundary layer characteristics. The results are as follows: the northwest flow and cold advection at 500 hPa, weak wind on the ground, updraftdowndraft distribution for vertical velocity, and inversion were the common features when fog or haze occurred. Northwest wind, cold advection at 850 hPa, shallow ground inversion (100 to 200 m), and thin wet layer corresponded with the haze. In contrast, east wind, warm advection at 850 hPa, deep suspended inversion (400 m) beneath 925 hPa, and thick wet layer corresponded with fog. The height of updraft was higher and the average intensity of inversion was stronger when the haze happened. The height of downdraft for the fog gone was lower and the intensity was weaker simultaneously. When the haze dissipated, the ground inversion almost had no change but for the fog, there were changes: bottomlifted suspension inversion and stable atmospheric stratification shifting to neutral. When the fog and haze disappeared, there were the following common features: downdrafts at upper levels reached at the ground; vertical wind shear increased and the dry air at upper levels with low dew point was transported to the ground.
Based on conventional observational data, NECP 1°×1° reanalysis data, and Lband sounding second data, two fog and haze cases occurred in 2013 are analyzed,including the circulation situation, diffusion conditions, and boundary layer characteristics. The results are as follows: the northwest flow and cold advection at 500 hPa, weak wind on the ground, updraftdowndraft distribution for vertical velocity, and inversion were the common features when fog or haze occurred. Northwest wind, cold advection at 850 hPa, shallow ground inversion (100 to 200 m), and thin wet layer corresponded with the haze. In contrast, east wind, warm advection at 850 hPa, deep suspended inversion (400 m) beneath 925 hPa, and thick wet layer corresponded with fog. The height of updraft was higher and the average intensity of inversion was stronger when the haze happened. The height of downdraft for the fog gone was lower and the intensity was weaker simultaneously. When the haze dissipated, the ground inversion almost had no change but for the fog, there were changes: bottomlifted suspension inversion and stable atmospheric stratification shifting to neutral. When the fog and haze disappeared, there were the following common features: downdrafts at upper levels reached at the ground; vertical wind shear increased and the dry air at upper levels with low dew point was transported to the ground.
2017, 45(1):179-183.
Abstract:
Based on the development situation of the current lightning disaster risk regionalization, the paper starts with the prior risk assessment of regional lightning disaster risk and uses the disaster bearing body and hazard body model to establish evaluation indicators, which contain lightning risk, regional risk and disasters. By this model, the parameters with higher degree of intimacy are selected to study the prior hazard assessment of regional lightning disaster risk. Taking Fujian Province as an example to apply the model, the results indicate that this model can reflect well the degree of loss in lightning disaster areas. It is of positive significance to the researches on regional lightning disaster risk and the support of decision making for regional governments.
Based on the development situation of the current lightning disaster risk regionalization, the paper starts with the prior risk assessment of regional lightning disaster risk and uses the disaster bearing body and hazard body model to establish evaluation indicators, which contain lightning risk, regional risk and disasters. By this model, the parameters with higher degree of intimacy are selected to study the prior hazard assessment of regional lightning disaster risk. Taking Fujian Province as an example to apply the model, the results indicate that this model can reflect well the degree of loss in lightning disaster areas. It is of positive significance to the researches on regional lightning disaster risk and the support of decision making for regional governments.
2017, 45(1):184-188.
Abstract:
Base on the TITAN products of SWAN and Technology of SafeShot Areas, the ground weather modification command system is build. In order to make the warning products and operational recommendations more timely and accuracy, the system improved the warning and operational product algorithm: (1) improved early warning algorithm to reduce the probability of missing warning, with the warning of the TITAN storm path extrapolation instead of TITAN area identification; (2) for the areas without weather radar, where there is a time lag in using the wholeprovince radar mosaic data, the data delay setting function is introduced to improve the timeliness and accuracy of weather modification operations. By improving the algorithm, the system can satisfy the demands of ground weather modification operations and has a certain popularization value.
Base on the TITAN products of SWAN and Technology of SafeShot Areas, the ground weather modification command system is build. In order to make the warning products and operational recommendations more timely and accuracy, the system improved the warning and operational product algorithm: (1) improved early warning algorithm to reduce the probability of missing warning, with the warning of the TITAN storm path extrapolation instead of TITAN area identification; (2) for the areas without weather radar, where there is a time lag in using the wholeprovince radar mosaic data, the data delay setting function is introduced to improve the timeliness and accuracy of weather modification operations. By improving the algorithm, the system can satisfy the demands of ground weather modification operations and has a certain popularization value.
2017, 45(1):189-194.
Abstract:
The weather process during the galloping accident of iced power lines occurring in Hubei Province on 10 and 11 February 2010 is analyzed using the Weather Research and Forecasting Model (WRF) and the Jones ice accretion model, and a preliminary study of the severe weather predictability is conducted. The results show that: the simulation of ice thickness based on observed precipitation is 13 to 54 mm with the Jones wire icing model, and consistent in order of magnitude with the observed. Because of the overestimated precipitation by the WRF model, the wire icing thickness is larger than observation. The results of the WRF model show good agreement with observation in wind speed at 10 m (the simulated is about 5 to 10 m〖DK〗·s-1 and the north wind is prevailing). The transmission lines in Hubei Province are mostly oriented in the eastwest direction, more prone to ice galloping accidents.
The weather process during the galloping accident of iced power lines occurring in Hubei Province on 10 and 11 February 2010 is analyzed using the Weather Research and Forecasting Model (WRF) and the Jones ice accretion model, and a preliminary study of the severe weather predictability is conducted. The results show that: the simulation of ice thickness based on observed precipitation is 13 to 54 mm with the Jones wire icing model, and consistent in order of magnitude with the observed. Because of the overestimated precipitation by the WRF model, the wire icing thickness is larger than observation. The results of the WRF model show good agreement with observation in wind speed at 10 m (the simulated is about 5 to 10 m〖DK〗·s-1 and the north wind is prevailing). The transmission lines in Hubei Province are mostly oriented in the eastwest direction, more prone to ice galloping accidents.
30 Characteristics and Prediction of Key Climatic Factors Affecting Rate of Marketable Fruits in Wuhu
2017, 45(1):195-202.
Abstract:
Using the data of the rate of marketable fruits from 1994 to 2014 in the study area, the monthly meteorological data in Wuhu from 1965 to 2014, 88 new monthly general circulation indexes from July 1981 to June 2014 and 26 SST indexes from the national climate center, based on correlation analysis, linear trend analysis, MannKendall, and stepwise multiple regression analysis, the key climatic factors influencing the rate of marketable fruits are chosen. On this basis, the characteristics and predictions of the chosen climatic factors are analyzed. The results show that the key influence climatic factors include monthly average temperature (〖WTBX〗T〖WTBZ〗7,〖WTBX〗T〖WTBZ〗8), monthly average maximum temperature (〖WTBX〗Tmax〖WTBZ〗7,〖WTBX〗Tmax〖WTBZ〗8), monthly average minimum temperature (〖WTBX〗Tmin〖WTBZ〗7,〖WTBX〗Tmin〖WTBZ〗8), monthly average relative humidity (〖WTBX〗RH〖WTBZ〗7,〖WTBX〗RH〖WTBZ〗8), monthly average sunshine duration (〖WTBX〗S〖WTBZ〗7,〖WTBX〗S〖WTBZ〗8) in July and August, monthly average daily temperature range (Δ〖WTBX〗T〖WTBZ〗8) in August. In nearly 50 years, 〖WTBX〗T〖WTBZ〗7、〖WTBX〗Tmax〖WTBZ〗7,and 〖WTBX〗Tmin〖WTBZ〗7raised significantly, but 〖WTBX〗RH〖WTBZ〗7、Δ〖WTBX〗T〖WTBZ〗8, and 〖WTBX〗S〖WTBZ〗8dropped significantly. 〖WTBX〗T〖WTBZ〗7、〖WTBX〗Tmax〖WTBZ〗7、Δ〖WTBX〗T〖WTBZ〗8showed a gradual feature, and 〖WTBX〗Tmin〖WTBZ〗7、〖WTBX〗RH〖WTBZ〗7、Δ〖WTBX〗T〖WTBZ〗8changed suddenly. These key climatic factors were significantly correlated with many general circulation indexes and SST indexes in previous 12 months, from which key indicators are chosen as the shortterm climatic forecast indexes of the key climatic factors influencing the rate of grape marketable fruits in July and August in Wuhu, and the predicting equations of the key climatic factors are worked out. This study can provide references for grape planting in dealing with the impacts of climate change effectively.
Using the data of the rate of marketable fruits from 1994 to 2014 in the study area, the monthly meteorological data in Wuhu from 1965 to 2014, 88 new monthly general circulation indexes from July 1981 to June 2014 and 26 SST indexes from the national climate center, based on correlation analysis, linear trend analysis, MannKendall, and stepwise multiple regression analysis, the key climatic factors influencing the rate of marketable fruits are chosen. On this basis, the characteristics and predictions of the chosen climatic factors are analyzed. The results show that the key influence climatic factors include monthly average temperature (〖WTBX〗T〖WTBZ〗7,〖WTBX〗T〖WTBZ〗8), monthly average maximum temperature (〖WTBX〗Tmax〖WTBZ〗7,〖WTBX〗Tmax〖WTBZ〗8), monthly average minimum temperature (〖WTBX〗Tmin〖WTBZ〗7,〖WTBX〗Tmin〖WTBZ〗8), monthly average relative humidity (〖WTBX〗RH〖WTBZ〗7,〖WTBX〗RH〖WTBZ〗8), monthly average sunshine duration (〖WTBX〗S〖WTBZ〗7,〖WTBX〗S〖WTBZ〗8) in July and August, monthly average daily temperature range (Δ〖WTBX〗T〖WTBZ〗8) in August. In nearly 50 years, 〖WTBX〗T〖WTBZ〗7、〖WTBX〗Tmax〖WTBZ〗7,and 〖WTBX〗Tmin〖WTBZ〗7raised significantly, but 〖WTBX〗RH〖WTBZ〗7、Δ〖WTBX〗T〖WTBZ〗8, and 〖WTBX〗S〖WTBZ〗8dropped significantly. 〖WTBX〗T〖WTBZ〗7、〖WTBX〗Tmax〖WTBZ〗7、Δ〖WTBX〗T〖WTBZ〗8showed a gradual feature, and 〖WTBX〗Tmin〖WTBZ〗7、〖WTBX〗RH〖WTBZ〗7、Δ〖WTBX〗T〖WTBZ〗8changed suddenly. These key climatic factors were significantly correlated with many general circulation indexes and SST indexes in previous 12 months, from which key indicators are chosen as the shortterm climatic forecast indexes of the key climatic factors influencing the rate of grape marketable fruits in July and August in Wuhu, and the predicting equations of the key climatic factors are worked out. This study can provide references for grape planting in dealing with the impacts of climate change effectively.
31 Characteristics of Climate Warming in Guilin and Its Impact on Phenological Phases of Local Citrus
2017, 45(1):203-208.
Abstract:
After comparing the climate data of 1984 to 2014 in Guilin with local citrus growth cycle data for the same period, with the application of the linear trend estimation, correlation coefficients of SPSS and other methods, the characteristics of Guilin’s climate warming and its impact on the phenological phase of local citrus are studied. The results shows that the warming trend in Guilin in 31 years was obvious, with the following main features: the annual average temperature rose by about 04 ℃; the climate in the late 1990s and early 2000s heated up significantly, with the main and the most significant warming in spring and winter, slight warming in summer and fall. On the other hand, the change of local citrus’s phenological phase caused by climate warming was marked, thus spring phenological phase came in advance while autumn phenological phase delayed, contributing to a trend of growing season being extended. In addition, temperature is the most distinctive meteorological factor that impacts the local citrus’s phenological phase greatly. February average maximum temperature increased by 1 ℃; therefore, orange buds opened in advance about 3 to 4 days; the March average maximum temperature increased by 1 ℃, so the flowering period came in advance about 4 to 9 days; because the annual extreme maximum temperature increased by 1 ℃, the maturity postponed 68 days.
After comparing the climate data of 1984 to 2014 in Guilin with local citrus growth cycle data for the same period, with the application of the linear trend estimation, correlation coefficients of SPSS and other methods, the characteristics of Guilin’s climate warming and its impact on the phenological phase of local citrus are studied. The results shows that the warming trend in Guilin in 31 years was obvious, with the following main features: the annual average temperature rose by about 04 ℃; the climate in the late 1990s and early 2000s heated up significantly, with the main and the most significant warming in spring and winter, slight warming in summer and fall. On the other hand, the change of local citrus’s phenological phase caused by climate warming was marked, thus spring phenological phase came in advance while autumn phenological phase delayed, contributing to a trend of growing season being extended. In addition, temperature is the most distinctive meteorological factor that impacts the local citrus’s phenological phase greatly. February average maximum temperature increased by 1 ℃; therefore, orange buds opened in advance about 3 to 4 days; the March average maximum temperature increased by 1 ℃, so the flowering period came in advance about 4 to 9 days; because the annual extreme maximum temperature increased by 1 ℃, the maturity postponed 68 days.
External LinksChina Meteorological AdministrationCMA Meteorological Observation CentreChinese Academy of Meteorological SciencesBeijing Meteorological ServiceNational Satellite Meteorological Center
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Supported by:Beijing E-Tiller Technology Development Co., Ltd.