Volume 43,Issue 6,2015 Table of Contents
2015, 43(6):1007-1014.
Abstract:
The integrated application of geostationary meteorological satellite and polar orbit meteorological satellite can maximize their advantages. The East Asian multisatellite integrated precipitation operational software follows Lagrange integration algorithm. The infrared cold cloud motion vectors calculated from geostationary meteorological satellite infrared brightness temperature provide constraints for propagating and morphing of polar orbit meteorological satellite microwave precipitation retrievals. Then the geostationary meteorological satellite infrared information is integrated with polar orbit meteorological satellite microwave information. During the software design, the overall framework of multidata hierarchical management and plugin multiservice unit cooperation are considered to provide the basic guarantee for operational software’s stability, fast data processing capability, future data change, and algorithm update.
The integrated application of geostationary meteorological satellite and polar orbit meteorological satellite can maximize their advantages. The East Asian multisatellite integrated precipitation operational software follows Lagrange integration algorithm. The infrared cold cloud motion vectors calculated from geostationary meteorological satellite infrared brightness temperature provide constraints for propagating and morphing of polar orbit meteorological satellite microwave precipitation retrievals. Then the geostationary meteorological satellite infrared information is integrated with polar orbit meteorological satellite microwave information. During the software design, the overall framework of multidata hierarchical management and plugin multiservice unit cooperation are considered to provide the basic guarantee for operational software’s stability, fast data processing capability, future data change, and algorithm update.
Dang Xuanfa
,
Kong Lingwang
,
Han Yuting
,
Liu Yongqiang
,
Huang Rui
,
Song Yuan
,
Yang Yongxiang
,
Wang Xin
2015, 43(6):1015-1018.
Abstract:
Rainfall gauges (meters) are the main observation instrument of precipitation. In order to ensure the accuracy of the measurement results, the calibration and field verification are very necessary. A rain gauge (meter) indoor test instrument is devised, which can also carry out calibration in outdoor tests. The calibrating instrument uses the measurement standards traceable to the ball as the standard. A peristaltic pump is used for the constant velocity control of rainfall intensity and a power controller and a storage battery are used to realize the outdoor rainfall instrument calibration without the alternating current. Through the analysis of tests and application, it is found that its performance is better than similar domestic products, and it complies with the measurement standards of traceability for rain gauges (meters). It is applicable to calibration and field verfication, and can be used for the field verification of rainfall sensors in automatic weather stations.
Rainfall gauges (meters) are the main observation instrument of precipitation. In order to ensure the accuracy of the measurement results, the calibration and field verification are very necessary. A rain gauge (meter) indoor test instrument is devised, which can also carry out calibration in outdoor tests. The calibrating instrument uses the measurement standards traceable to the ball as the standard. A peristaltic pump is used for the constant velocity control of rainfall intensity and a power controller and a storage battery are used to realize the outdoor rainfall instrument calibration without the alternating current. Through the analysis of tests and application, it is found that its performance is better than similar domestic products, and it complies with the measurement standards of traceability for rain gauges (meters). It is applicable to calibration and field verfication, and can be used for the field verification of rainfall sensors in automatic weather stations.
Xiao Jianhui
,
Zhang Hongying
,
Wu Xiangjuan
,
Wang Shaohui
,
Yao Aiguo
,
Dang Xuanfa
,
Zhang Erguo
,
Wu Ning
2015, 43(6):1019-1024.
Abstract:
Measurement comparison is organized by the Ningxia Meteorological Metrology Calibration Laboratory to verify the calibration capability of the Northwest China meteorological metrological institutes. Temperature, humidity, and pressure are involved, and automatic weather station sensors are used in the experiments. The leading laboratory is in charge of data collection and analysis. The comparison result analysis is carried out by means of normalized standard deviation. The comparison results of temperature and pressure are very satisfactory, and that of humidity is satisfactory. The comparison test data is realistic and credible. The results can reflect the level of verification or calibration, and the current situation of meteorological measurement standard devices of reference laboratories objectively. It can also identify the problems existed in the reference laboratories effectively, which is very important in improving the capability of calibration laboratories.
Measurement comparison is organized by the Ningxia Meteorological Metrology Calibration Laboratory to verify the calibration capability of the Northwest China meteorological metrological institutes. Temperature, humidity, and pressure are involved, and automatic weather station sensors are used in the experiments. The leading laboratory is in charge of data collection and analysis. The comparison result analysis is carried out by means of normalized standard deviation. The comparison results of temperature and pressure are very satisfactory, and that of humidity is satisfactory. The comparison test data is realistic and credible. The results can reflect the level of verification or calibration, and the current situation of meteorological measurement standard devices of reference laboratories objectively. It can also identify the problems existed in the reference laboratories effectively, which is very important in improving the capability of calibration laboratories.
2015, 43(6):1025-1029.
Abstract:
According to the observations of wind data analysis from Lband radar at Yangjiang radiosonde station of Guangdong, there sometimes appear some cases of inconsistence with the theoretical values if using comprehensive detection radar or no slant distance (or height replacement) wind measurement methods to calculate the results at the wind measurement levels．The results from these two methods in wind measuring are sometimes beyond the permitted error range of upperlevel meteorological observation instruments for overall measurement accuracy. Results show that when the radar elevation angle is less than 30° and the wind speed of the wind measurement level is <3 m/s, the wind speeds calculated from the two kinds of wind methods are almost the same， with the errors within the permitted range, but there are large differences sometimes in wind direction, beyond the allowed error range. When radar elevation angle is less than 15° and the wind speed in the wind measurement level is >30 m/s, the wind directions in the measure wind layer calculated by the two methods are close, but the differences in wind speed in the wind measurement levels are comparatively large, also beyond the allowed error range.
According to the observations of wind data analysis from Lband radar at Yangjiang radiosonde station of Guangdong, there sometimes appear some cases of inconsistence with the theoretical values if using comprehensive detection radar or no slant distance (or height replacement) wind measurement methods to calculate the results at the wind measurement levels．The results from these two methods in wind measuring are sometimes beyond the permitted error range of upperlevel meteorological observation instruments for overall measurement accuracy. Results show that when the radar elevation angle is less than 30° and the wind speed of the wind measurement level is <3 m/s, the wind speeds calculated from the two kinds of wind methods are almost the same， with the errors within the permitted range, but there are large differences sometimes in wind direction, beyond the allowed error range. When radar elevation angle is less than 15° and the wind speed in the wind measurement level is >30 m/s, the wind directions in the measure wind layer calculated by the two methods are close, but the differences in wind speed in the wind measurement levels are comparatively large, also beyond the allowed error range.
2015, 43(6):1030-1039.
Abstract:
Lack of detection mechanisms for operational status of meteorological observation equipment has been a major challenge to China’s surface meteorological observation operation and support service. To meet the actual demands of operation monitoring, the structures of the existing inservice surface automatic weather observation equipment are outlined, in combination with the related research findings, the status detection points of each main component are subdivided, classified, and encoded one by one in 10 modules: data collection module, barometric observation module, temperature and humidity observation module, wind observation module, surface temperature observation module, rain observation module, power supply system module, software module, visibility observation module, and weighing precipitation observation module. With reference to the long Z data files of the existing inservice equipment, the operational status messaging specifications of automatic surface weather observation equipment are formulated and the information detection technology for monitoring the operational status of automatic surface meteorological observation equipment is developed. The technology, to some extent, solved the problem—lack of design specifications for monitoring information of surface meteorological observation equipment in China. The current unfavorable situation featured by numerous manufacturers, varied models, and nonstandard equipment can be mitigated by setting up the unified specifications and standards, to facilitate the standardization of automatic surface meteorological observation equipment operational monitoring technology.
Lack of detection mechanisms for operational status of meteorological observation equipment has been a major challenge to China’s surface meteorological observation operation and support service. To meet the actual demands of operation monitoring, the structures of the existing inservice surface automatic weather observation equipment are outlined, in combination with the related research findings, the status detection points of each main component are subdivided, classified, and encoded one by one in 10 modules: data collection module, barometric observation module, temperature and humidity observation module, wind observation module, surface temperature observation module, rain observation module, power supply system module, software module, visibility observation module, and weighing precipitation observation module. With reference to the long Z data files of the existing inservice equipment, the operational status messaging specifications of automatic surface weather observation equipment are formulated and the information detection technology for monitoring the operational status of automatic surface meteorological observation equipment is developed. The technology, to some extent, solved the problem—lack of design specifications for monitoring information of surface meteorological observation equipment in China. The current unfavorable situation featured by numerous manufacturers, varied models, and nonstandard equipment can be mitigated by setting up the unified specifications and standards, to facilitate the standardization of automatic surface meteorological observation equipment operational monitoring technology.
2015, 43(6):1040-1045.
Abstract:
The design and implementation process of an automatic voice alarm system based on IMS are introduced. The process consists of hardware and software architecture. Compared with the schemes based on voice cards, the hardware system is based on a multimedia switch and supported by IMS; therefore, it has the advantages of high stability, concurrency, and strong expansibility. The software system is built under C/S and B/S structures: the C/S part with high manageability and configurability collects exceptions appeared in the meteorological communication and sends corresponding voice alarm, while the B/S part is responsible for the display, statistics and analysis of alarm information. The application results show that the automatic voice alarm system is stable and reliable.
The design and implementation process of an automatic voice alarm system based on IMS are introduced. The process consists of hardware and software architecture. Compared with the schemes based on voice cards, the hardware system is based on a multimedia switch and supported by IMS; therefore, it has the advantages of high stability, concurrency, and strong expansibility. The software system is built under C/S and B/S structures: the C/S part with high manageability and configurability collects exceptions appeared in the meteorological communication and sends corresponding voice alarm, while the B/S part is responsible for the display, statistics and analysis of alarm information. The application results show that the automatic voice alarm system is stable and reliable.
2015, 43(6):1046-1052.
Abstract:
Conventional automatic weather stations depend on the electricity and communications infrastructure strongly and the application environment is also restricted. The meteorological observation node based on a wireless sensor network is designed and implemented. The hardware system of weather observation nodes uses the CC2530 chip as the core and lithium batteries as supply power, and connects meteorological sensors via analog and digital interfaces and works on 2.4 GHz. The software system is based on the TinyOS operating system, and various kinds of meteorological sensor drivers and a multihop routing protocol based on LEPS protocol are developed. A test is conducted in field environment, including power, communication distance, sensors, and network performance. Test results show that the meteorological observation nodes form a stable multihop selforganizing data collection and transmission network in the environment without electricity and communications infrastructure. Therefore, it is suitable for deployment and application in the difficult areas such as high mountains, islands and deserts.
Conventional automatic weather stations depend on the electricity and communications infrastructure strongly and the application environment is also restricted. The meteorological observation node based on a wireless sensor network is designed and implemented. The hardware system of weather observation nodes uses the CC2530 chip as the core and lithium batteries as supply power, and connects meteorological sensors via analog and digital interfaces and works on 2.4 GHz. The software system is based on the TinyOS operating system, and various kinds of meteorological sensor drivers and a multihop routing protocol based on LEPS protocol are developed. A test is conducted in field environment, including power, communication distance, sensors, and network performance. Test results show that the meteorological observation nodes form a stable multihop selforganizing data collection and transmission network in the environment without electricity and communications infrastructure. Therefore, it is suitable for deployment and application in the difficult areas such as high mountains, islands and deserts.
2015, 43(6):1053-1059.
Abstract:
Concerning the difficults in data management and organization of prefecturelevel meteorological database systems,a novel approach for architecture and design of meteorological database system is presented under the framework of standardization and normalization. The physical storage model and uniform interface specification of meteorological data are designed through the logical and physical classification of those data. In addition, to archive a uniform treating effect of meteorological data acquisition, transmission, storage, and backup, a data processing method is presented based on RabbitMQ and metadata technology, which enhances the flexibility and extensibility of meteorological data processing through the mapping relationship of message data and metadata. The system has been put into operation, which provides stable, efficient data support for meteorological data management and public service.
Concerning the difficults in data management and organization of prefecturelevel meteorological database systems,a novel approach for architecture and design of meteorological database system is presented under the framework of standardization and normalization. The physical storage model and uniform interface specification of meteorological data are designed through the logical and physical classification of those data. In addition, to archive a uniform treating effect of meteorological data acquisition, transmission, storage, and backup, a data processing method is presented based on RabbitMQ and metadata technology, which enhances the flexibility and extensibility of meteorological data processing through the mapping relationship of message data and metadata. The system has been put into operation, which provides stable, efficient data support for meteorological data management and public service.
2015, 43(6):1060-1064.
Abstract:
The airborne cloud and precipitation particle image probe for aircraft observation is the main detection method for cloud microphysics research. Before transferred and stored in PC, particle image data from the image probe should be compressed, which makes it necessary to use special software for subsequent particle image playback. Based on the structure analysis of cloud particle image data, the combination of message queuing and JKI state machine is used in the system design of software structure. Using the graphic programming language LabVIEW, the cloud and precipitation particle image playback software is developed, which can display, extract, and store the information of cloud and precipitation particle images and provide references for researches on cloud and precipitation physics.
The airborne cloud and precipitation particle image probe for aircraft observation is the main detection method for cloud microphysics research. Before transferred and stored in PC, particle image data from the image probe should be compressed, which makes it necessary to use special software for subsequent particle image playback. Based on the structure analysis of cloud particle image data, the combination of message queuing and JKI state machine is used in the system design of software structure. Using the graphic programming language LabVIEW, the cloud and precipitation particle image playback software is developed, which can display, extract, and store the information of cloud and precipitation particle images and provide references for researches on cloud and precipitation physics.
2015, 43(6):1065-1069.
Abstract:
The development of a realtime monitoring software for the transmission of meteorological data compatible with smart phones by using Mono for Android, ASP.NET and C# to ensure the timeliness of transmission is introduced, and the realtime monitoring of the transmission of meteorological data in a secure, timely and accurate fashion is described in terms of software requirement analysis, software architecture and implementation. It gives a detailed presentation of the main functions of the software and their optimization. The software can be used to obtain, publish, and transmit data and achieve user control with Web service. It can optimize the performance of Web service to ensure the security and efficiency of data transmission. It can also use backstage service, implicit threading, and timing warning to develop quickresponse smart phone clients and create resolutionindependent UI.
The development of a realtime monitoring software for the transmission of meteorological data compatible with smart phones by using Mono for Android, ASP.NET and C# to ensure the timeliness of transmission is introduced, and the realtime monitoring of the transmission of meteorological data in a secure, timely and accurate fashion is described in terms of software requirement analysis, software architecture and implementation. It gives a detailed presentation of the main functions of the software and their optimization. The software can be used to obtain, publish, and transmit data and achieve user control with Web service. It can optimize the performance of Web service to ensure the security and efficiency of data transmission. It can also use backstage service, implicit threading, and timing warning to develop quickresponse smart phone clients and create resolutionindependent UI.
2015, 43(6):1070-1073.
Abstract:
The Weather Service Data Open Platform is similar to the Baidu, Taobao, and Tencent open platforms, based on http (Hypertext Transfer Protocol, Hypertext Transfer Protocol) application programming interfaces for individuals and organizations in society to provide meteorological services data. The Nginx Web Server platform data interface provides Web services, using the Nginx Module to handle user requests and business logic. By means of the Nginx module’s features of small footprint, high concurrency, and high stability, it can address the massive user access problems caused by the high load Web Server. The platform consists of three subplatform business process compositions, i.e., API interface platform, user application platform, and business management platform), being responsible for interface request processing, user application management, and background management.
The Weather Service Data Open Platform is similar to the Baidu, Taobao, and Tencent open platforms, based on http (Hypertext Transfer Protocol, Hypertext Transfer Protocol) application programming interfaces for individuals and organizations in society to provide meteorological services data. The Nginx Web Server platform data interface provides Web services, using the Nginx Module to handle user requests and business logic. By means of the Nginx module’s features of small footprint, high concurrency, and high stability, it can address the massive user access problems caused by the high load Web Server. The platform consists of three subplatform business process compositions, i.e., API interface platform, user application platform, and business management platform), being responsible for interface request processing, user application management, and background management.
2015, 43(6):1074-1084.
Abstract:
In order to provide a valuable reference to shortterm weather forecast of convective gales, the indices of forecast and early warning are summarized from 〖WTBX〗T〖WTBZ〗ln〖WTBX〗p〖WTBZ〗, convective parameters, radar echoes, etc. According to the cases of gales from 2006 to 2009, it is found that gales frequently occurred in summer and had a local feature, showing bimodal distribution with the peak values in April and July. The convective parameters had indicative meaning for convective gale forecasting. The beginning of a convective gale can be distinguished by radar echo intensity, radial velocity (≥10 m〖DK〗·s-1 at 0.5° radar elevation), and the rapid reduction after the appearing of maximum echo top height and VIL.
In order to provide a valuable reference to shortterm weather forecast of convective gales, the indices of forecast and early warning are summarized from 〖WTBX〗T〖WTBZ〗ln〖WTBX〗p〖WTBZ〗, convective parameters, radar echoes, etc. According to the cases of gales from 2006 to 2009, it is found that gales frequently occurred in summer and had a local feature, showing bimodal distribution with the peak values in April and July. The convective parameters had indicative meaning for convective gale forecasting. The beginning of a convective gale can be distinguished by radar echo intensity, radial velocity (≥10 m〖DK〗·s-1 at 0.5° radar elevation), and the rapid reduction after the appearing of maximum echo top height and VIL.
2015, 43(6):1085-1094.
Abstract:
The characteristics of 15 events precipitation in 2010 are analyzed based on the data observed by the raindrop disdrometer in Donguan, Guangdong Province. Six typical cases, including 2 stratiform precipitation (S), 2 Mixed convective and Stratiform precipitation (M), and 2 convective precipitation (C) events, are selected to analyze the relevance of various feature parameters and the characteristics of rain drop size distribution. The results show that the regularities of the distribution of parameters, including average particle diameter, average rainfall intensity, average rainwater content, the largest cube root diameter, and the most rainfall intensity, are C>M>S; the raindrop spectrum models of the precipitation produced by the same type of clouds are very close to each other, and there is a single peak spectrum in 2 Stype precipitation. The raindrop size distributions of Mand Ctype precipitation are obvious 2 or multipeak model. There are more bigger raindrops in Mand Ctype precipitation than in Stype precipitation; the relevance between rainwater content and rainfall intensity is the best, and that between radar reflectivity and rainfall intensity is the next; there are mainly small particles below 1 mm in Stype precipitation; the widths of raindrop spectrum of Mand Ctype precipitation are bigger than that of Stype precipitation， and there are more particles of over 1 mm.
The characteristics of 15 events precipitation in 2010 are analyzed based on the data observed by the raindrop disdrometer in Donguan, Guangdong Province. Six typical cases, including 2 stratiform precipitation (S), 2 Mixed convective and Stratiform precipitation (M), and 2 convective precipitation (C) events, are selected to analyze the relevance of various feature parameters and the characteristics of rain drop size distribution. The results show that the regularities of the distribution of parameters, including average particle diameter, average rainfall intensity, average rainwater content, the largest cube root diameter, and the most rainfall intensity, are C>M>S; the raindrop spectrum models of the precipitation produced by the same type of clouds are very close to each other, and there is a single peak spectrum in 2 Stype precipitation. The raindrop size distributions of Mand Ctype precipitation are obvious 2 or multipeak model. There are more bigger raindrops in Mand Ctype precipitation than in Stype precipitation; the relevance between rainwater content and rainfall intensity is the best, and that between radar reflectivity and rainfall intensity is the next; there are mainly small particles below 1 mm in Stype precipitation; the widths of raindrop spectrum of Mand Ctype precipitation are bigger than that of Stype precipitation， and there are more particles of over 1 mm.
2015, 43(6):1095-1103.
Abstract:
The Qinghai Tibet Plateau is a sensitive area to global climate change. By using the mesoscale model WRF3.5.1, selecting the Tibet Plateau (26° to 39°N, 73° to 104°E) as a critical area, in order to discuss the possible effects of initial anomaly soil moisture on short term climate change in summer over China. Results show that soil moisture has obvious effects on the regionalscale climate. In wet soil moisture conditions, precipitation in the most parts of China increases, especially in parts of Northeast China and East China; meanwhile, temperature in the most parts of China decreases generally and distinctly. In dry soil moisture conditions, the precipitation in the most parts of China decreases along with rising temperature. In conclusion, wet soil has mainly positive feedback effect on precipitation and negative feedback on temperature.
The Qinghai Tibet Plateau is a sensitive area to global climate change. By using the mesoscale model WRF3.5.1, selecting the Tibet Plateau (26° to 39°N, 73° to 104°E) as a critical area, in order to discuss the possible effects of initial anomaly soil moisture on short term climate change in summer over China. Results show that soil moisture has obvious effects on the regionalscale climate. In wet soil moisture conditions, precipitation in the most parts of China increases, especially in parts of Northeast China and East China; meanwhile, temperature in the most parts of China decreases generally and distinctly. In dry soil moisture conditions, the precipitation in the most parts of China decreases along with rising temperature. In conclusion, wet soil has mainly positive feedback effect on precipitation and negative feedback on temperature.
2015, 43(6):1104-1109.
Abstract:
A precipitation index is designed and calculated, selecting such factors to be ingredients of IngredientsBased Forecasting Methodology as the divergence of nongeostrophic wet 〖WTHX〗Q〖WTBZ〗vector, MPV, and total volume water vapor. It is found that the precipitation index is in good agreement with real precipitation in value and trends. The precipitation index can reflect the wet and dry periods. With the NCEP CFSv2 data of April to June 2014, the precipitation index is calculated. The monthly precipitation index value can well reflect the maximum rainfall in May (usually in June). Ingredient method can provide a useful reference for shortterm climate prediction.
A precipitation index is designed and calculated, selecting such factors to be ingredients of IngredientsBased Forecasting Methodology as the divergence of nongeostrophic wet 〖WTHX〗Q〖WTBZ〗vector, MPV, and total volume water vapor. It is found that the precipitation index is in good agreement with real precipitation in value and trends. The precipitation index can reflect the wet and dry periods. With the NCEP CFSv2 data of April to June 2014, the precipitation index is calculated. The monthly precipitation index value can well reflect the maximum rainfall in May (usually in June). Ingredient method can provide a useful reference for shortterm climate prediction.
2015, 43(6):1110-1115.
Abstract:
Based on the daily maximum air temperature data from 74 stations in Hunan from 1961 to 2013, the complete time series of hot days is established. The temporal and spatial distribution and changing trend of hot days in Hunan during last 53 years are analyzed. The results show that hot days show an increasing trend with an increase rate of 2 days per 10 years, which is more obvious in the northern Hunan. The maximum hot duration shows a weak decreasing trend in the southern Hunan with a reducing rate of 0.5 days per 10 years, but there is a strong increasing trend in the north and central parts of Hunan with an increase rate of 1 day per 10 years. Since the 1990s, hot days in Hunan have increased and enhanced significantly. A climatic prediction model of hot days is established using the optimal subset regression method. The verification of the 53year historical records shows that the model can forecast hot days in Hunan satisfactorily, which can be put to operational use.
Based on the daily maximum air temperature data from 74 stations in Hunan from 1961 to 2013, the complete time series of hot days is established. The temporal and spatial distribution and changing trend of hot days in Hunan during last 53 years are analyzed. The results show that hot days show an increasing trend with an increase rate of 2 days per 10 years, which is more obvious in the northern Hunan. The maximum hot duration shows a weak decreasing trend in the southern Hunan with a reducing rate of 0.5 days per 10 years, but there is a strong increasing trend in the north and central parts of Hunan with an increase rate of 1 day per 10 years. Since the 1990s, hot days in Hunan have increased and enhanced significantly. A climatic prediction model of hot days is established using the optimal subset regression method. The verification of the 53year historical records shows that the model can forecast hot days in Hunan satisfactorily, which can be put to operational use.
2015, 43(6):1116-1120.
Abstract:
Different key factors are chosen and composed from the numerical forecast products of the models of ECMWF and T639 from 2013 to 2014, and the surface hourly temperature forecast are established by means of the nonlinear regressive methods—BP (Back Propagation) neural net， SVM (Support Vector Machine), and constructed nonlinear function methods. The results show that the error correction method can reduce forecast error more stably when the error is large; adjusted by the mean errors, all the three methods can forecast the hourly temperature satisfactorily, with mean absolute errors reduced generally by 0.5 ℃. The test of independent samples indicates that the mean absolute errors of hourly temperature forecast by utilizing the methods of BP, SVM, constructed nonlinear function, and error correction are less than 1.5 ℃, 1.7 ℃, 1.8 ℃, and 1.4 ℃, respectively. The constructed nonlinear function has a good performance in fitting and prediction in general.
Different key factors are chosen and composed from the numerical forecast products of the models of ECMWF and T639 from 2013 to 2014, and the surface hourly temperature forecast are established by means of the nonlinear regressive methods—BP (Back Propagation) neural net， SVM (Support Vector Machine), and constructed nonlinear function methods. The results show that the error correction method can reduce forecast error more stably when the error is large; adjusted by the mean errors, all the three methods can forecast the hourly temperature satisfactorily, with mean absolute errors reduced generally by 0.5 ℃. The test of independent samples indicates that the mean absolute errors of hourly temperature forecast by utilizing the methods of BP, SVM, constructed nonlinear function, and error correction are less than 1.5 ℃, 1.7 ℃, 1.8 ℃, and 1.4 ℃, respectively. The constructed nonlinear function has a good performance in fitting and prediction in general.
2015, 43(6):1121-1126.
Abstract:
The pentad mean temperature anomaly forecasting model of the Xinjiang area is established using Empirical Orthogonal Function decomposition (EOF), Ensemble Empirical Mode Decomposition (EEMD), and Least Square Support Vector Machine (LSSVM) methods. Using the EEMD to decompose the first three time series obtained from EOF into a series of Intrinsic Mode Function (IMF), the predicted IMF is acquired by using LSSVM. The acquisition of pentad mean temperature anomaly is from the forecast of time series and temporal reconstruction. Tendays mean temperature anomaly is acquired based on the pentad mean temperature anomaly, and the month mean temperature anomaly was acquired based on the 10days mean temperature anomaly. The model using the temporal anomaly correlation coefficients (ACC), the skill score (SS) and anomaly sign score (〖WTBX〗R〖WTBZ〗) are evaluated. The results show that the model worked well in the first 20 pentads with an average ACC of 0.32, average SS of 0.70, and average〖WTBX〗 R 〖WTBZ〗of 050. It worked well in the first ten 10day periods, with an average ACC of 0.50, average SS of 0.50, and average 〖WTBX〗R〖WTBZ〗 of 0.50. It also worked well in three months, with an average ACC of 0.50, an average SS of 0.50, and an average 〖WTBX〗R〖WTBZ〗 of 0.80.
The pentad mean temperature anomaly forecasting model of the Xinjiang area is established using Empirical Orthogonal Function decomposition (EOF), Ensemble Empirical Mode Decomposition (EEMD), and Least Square Support Vector Machine (LSSVM) methods. Using the EEMD to decompose the first three time series obtained from EOF into a series of Intrinsic Mode Function (IMF), the predicted IMF is acquired by using LSSVM. The acquisition of pentad mean temperature anomaly is from the forecast of time series and temporal reconstruction. Tendays mean temperature anomaly is acquired based on the pentad mean temperature anomaly, and the month mean temperature anomaly was acquired based on the 10days mean temperature anomaly. The model using the temporal anomaly correlation coefficients (ACC), the skill score (SS) and anomaly sign score (〖WTBX〗R〖WTBZ〗) are evaluated. The results show that the model worked well in the first 20 pentads with an average ACC of 0.32, average SS of 0.70, and average〖WTBX〗 R 〖WTBZ〗of 050. It worked well in the first ten 10day periods, with an average ACC of 0.50, average SS of 0.50, and average 〖WTBX〗R〖WTBZ〗 of 0.50. It also worked well in three months, with an average ACC of 0.50, an average SS of 0.50, and an average 〖WTBX〗R〖WTBZ〗 of 0.80.
2015, 43(6):1127-1132.
Abstract:
With the pan evaporation data, temperature, sunlight, precipitation, and some other meteorological data from 1971 to 2010 in Yantai, the changes in pan evaporation characteristics are analyzed. By using the linear regression, correlation analysis, wavelet analysis, and stepwise regression analysis methods, effects of meteorological factors on the changes of evaporation are analyzed. The results show that there existed periodic variation in annual evaporation with the main periods of 2 to 3 years and the periods of 4 to 8 and 8 to 12 years; there were periodic changes of 3 to 5, 5 to 7, 7 to 11, and 2 to 4 years, respectively, in evaporation in spring, summer, autumn, and winter. Increased average relative humidity and reduced sunshine duration brought about the reduction in annual evaporation, and factors influencing the changes of evaporation in different seasons were different. Sunshine duration and total cloud cover were the most important in summer and autumn. While in autumn and winter evaporation is mainly affected by average relative humidity, sunshine duration, and total cloud cover jointly.
With the pan evaporation data, temperature, sunlight, precipitation, and some other meteorological data from 1971 to 2010 in Yantai, the changes in pan evaporation characteristics are analyzed. By using the linear regression, correlation analysis, wavelet analysis, and stepwise regression analysis methods, effects of meteorological factors on the changes of evaporation are analyzed. The results show that there existed periodic variation in annual evaporation with the main periods of 2 to 3 years and the periods of 4 to 8 and 8 to 12 years; there were periodic changes of 3 to 5, 5 to 7, 7 to 11, and 2 to 4 years, respectively, in evaporation in spring, summer, autumn, and winter. Increased average relative humidity and reduced sunshine duration brought about the reduction in annual evaporation, and factors influencing the changes of evaporation in different seasons were different. Sunshine duration and total cloud cover were the most important in summer and autumn. While in autumn and winter evaporation is mainly affected by average relative humidity, sunshine duration, and total cloud cover jointly.
2015, 43(6):1133-1141.
Abstract:
Base on the conventional observational data and NCEP 1°×1° reanalysis data, the causes of low trough and coldfront rainfall processes without vortex or low level jet in the lower troposphere, one influenced by a backwardtilting trough and the other by a forwardtilting trough, are analyzed contrastively. The results show that although the circulation patterns of two processes in the lower troposphere were very similar, there were significant differences on the spatial structure. The front of the backwardtilting trough tilted toward the cold air and was divided into three sections. The cold air of the first section below 850 hPa was weak, but played a triggering role for the precipitation process. The rainfall distribution was on the leading edge of the first section in its moving direction, where the dense streamline zone in cyclonic convergence was on the ground. The front of the forwardtilting trough was complete, a wet baroclinic frontal zone inclined to the warm area. The rainfall distribution was 1 to 2 latitude distance in front of the front where the dense streamline zone in southward airflow was on the right side of the ground convergence line. Both heavy rain events had strong water vapor transport at lower levels, and there existed high temperature and high humidity, with humidity up to 15 g/kg at 925 hPa. The difference is that the rainfall area of the former was in the highvalue water vapor flux area in the front edge of the dense 〖WTBX〗θ〖WTBZ〗e lines in wind convergence region; while the rainfall area of the latter was in the dense water vapor flux isopleth zone at the tip of 〖WTBX〗θ〖WTBZ〗e warm tongue in wind convergence region, but more inclined to the warm air side. In addition, heavy rains often occurred in such special orographic uplift areas as mountainous areas or coastline.
Base on the conventional observational data and NCEP 1°×1° reanalysis data, the causes of low trough and coldfront rainfall processes without vortex or low level jet in the lower troposphere, one influenced by a backwardtilting trough and the other by a forwardtilting trough, are analyzed contrastively. The results show that although the circulation patterns of two processes in the lower troposphere were very similar, there were significant differences on the spatial structure. The front of the backwardtilting trough tilted toward the cold air and was divided into three sections. The cold air of the first section below 850 hPa was weak, but played a triggering role for the precipitation process. The rainfall distribution was on the leading edge of the first section in its moving direction, where the dense streamline zone in cyclonic convergence was on the ground. The front of the forwardtilting trough was complete, a wet baroclinic frontal zone inclined to the warm area. The rainfall distribution was 1 to 2 latitude distance in front of the front where the dense streamline zone in southward airflow was on the right side of the ground convergence line. Both heavy rain events had strong water vapor transport at lower levels, and there existed high temperature and high humidity, with humidity up to 15 g/kg at 925 hPa. The difference is that the rainfall area of the former was in the highvalue water vapor flux area in the front edge of the dense 〖WTBX〗θ〖WTBZ〗e lines in wind convergence region; while the rainfall area of the latter was in the dense water vapor flux isopleth zone at the tip of 〖WTBX〗θ〖WTBZ〗e warm tongue in wind convergence region, but more inclined to the warm air side. In addition, heavy rains often occurred in such special orographic uplift areas as mountainous areas or coastline.
2015, 43(6):1142-1148.
Abstract:
Using the realtime Doppler weather radar, boundary layer wind profiler radar, and automatic weather station data, the characteristic structure evolution in the 4th landing of supertyphoon Ramasun on the Guangxi coastal is studied. The results show that the typhoon eye area had characteristics of low atmospheric pressure, weak wind speed, dry and warm air, in which atmospheric pressure showed funnelshaped changes; the typhoon eye area maintained a round shape during typhoon landing, with a radius of 30 km, a typical strong typhoon structure. In addition, the large value area of the radial velocity in radar exhibited an asymmetrical feature with the right quadrant larger than the left quadrant. The error of surface measurements is only 5.4 m/s; the horizontal wind field of wind profiler radar can reflect the vertical structure accurately and intuitively in different parts of the typhoon. Wind direction had experienced a “northeasteastsoutheastsouth” change process, and the overall characteristics of wind speed increased first and then decreased. Moreover, the vertical speed, atmospheric refractive index,structure constant (C2n) can well reflect the variation of typhoon structure, typhoon clouds and airflow; wind direction was consistent in two types of weather radar wind field products, but in VWP products wind speed was smaller than that from wind profiler radar. When there are invalid data in VWP products, wind profiler radar products can be used as complementary.
Using the realtime Doppler weather radar, boundary layer wind profiler radar, and automatic weather station data, the characteristic structure evolution in the 4th landing of supertyphoon Ramasun on the Guangxi coastal is studied. The results show that the typhoon eye area had characteristics of low atmospheric pressure, weak wind speed, dry and warm air, in which atmospheric pressure showed funnelshaped changes; the typhoon eye area maintained a round shape during typhoon landing, with a radius of 30 km, a typical strong typhoon structure. In addition, the large value area of the radial velocity in radar exhibited an asymmetrical feature with the right quadrant larger than the left quadrant. The error of surface measurements is only 5.4 m/s; the horizontal wind field of wind profiler radar can reflect the vertical structure accurately and intuitively in different parts of the typhoon. Wind direction had experienced a “northeasteastsoutheastsouth” change process, and the overall characteristics of wind speed increased first and then decreased. Moreover, the vertical speed, atmospheric refractive index,structure constant (C2n) can well reflect the variation of typhoon structure, typhoon clouds and airflow; wind direction was consistent in two types of weather radar wind field products, but in VWP products wind speed was smaller than that from wind profiler radar. When there are invalid data in VWP products, wind profiler radar products can be used as complementary.
2015, 43(6):1149-1156.
Abstract:
Based on the NCEP/NCAR reanalysis data, the characteristics of Rammasun over the offshore of China are analyzed using the synoptic and dynamic diagnosis methods. The results show that high SST in the South China Sea and the abundant water vapor transport at lower and middle levels provided favorable energy for the intensification of Rammasun; weak vertical environmental wind shear between 0 to 4 ms-1 at lower, middle, and upper levels, which maintained nearly 22 hour, was a necessary condition for supertyphoon Rammasun landing two times; strong divergence at the upper level, positive vorticity which enlarged at the lower level, and the positive vorticity column stretched to the upper troposphere resulted in Rammasun increased sharply; there was a time lag of about 12 hours between the vertical wind shear change and the typhoon’s rapid intensity change; and the changing of vorticity at the lower troposphere was also about 9 hours earlier than typhoon strengthening.
Based on the NCEP/NCAR reanalysis data, the characteristics of Rammasun over the offshore of China are analyzed using the synoptic and dynamic diagnosis methods. The results show that high SST in the South China Sea and the abundant water vapor transport at lower and middle levels provided favorable energy for the intensification of Rammasun; weak vertical environmental wind shear between 0 to 4 ms-1 at lower, middle, and upper levels, which maintained nearly 22 hour, was a necessary condition for supertyphoon Rammasun landing two times; strong divergence at the upper level, positive vorticity which enlarged at the lower level, and the positive vorticity column stretched to the upper troposphere resulted in Rammasun increased sharply; there was a time lag of about 12 hours between the vertical wind shear change and the typhoon’s rapid intensity change; and the changing of vorticity at the lower troposphere was also about 9 hours earlier than typhoon strengthening.
2015, 43(6):1157-1163.
Abstract:
Continuous supply of water vapor is a necessary condition for the occurrence and development of a rainstorm. The groundbased GPS technology provides a new method for the detection of tropospheric water vapor, which provides technical guarantee for the accuracy and precision of weather forecast. The Bernese 5.0 software was used to process the groundbased GPS data in a heavy rainstorm on 21 July 2012 in Beijing.The temporal and spatial variation series of the PWV (Precipitable Water Vapor) are obtained and contrasted with radiosonde data. The results show that high spatial and temporal resolution groundbased GPS technology has obvious advantageous for the detection of atmospheric water vapor in the troposphere. The high correlation with the actual rainfall shows a positive significance of groundbased GPS technology in the monitoring and earlywarning of rainstorms. The results indicate that when higher PWV （>40 mm）continues in Beijing, within 24 to 36 hours there may occur a heavy rainfall; when PWV becomes very rich (increased 10 to 20 mm per hour) with sustainable PWV development in short time, a storm may be coming. The effective application of GPSMET technology in weather forecast can improve the precision and accuracy greatly.
Continuous supply of water vapor is a necessary condition for the occurrence and development of a rainstorm. The groundbased GPS technology provides a new method for the detection of tropospheric water vapor, which provides technical guarantee for the accuracy and precision of weather forecast. The Bernese 5.0 software was used to process the groundbased GPS data in a heavy rainstorm on 21 July 2012 in Beijing.The temporal and spatial variation series of the PWV (Precipitable Water Vapor) are obtained and contrasted with radiosonde data. The results show that high spatial and temporal resolution groundbased GPS technology has obvious advantageous for the detection of atmospheric water vapor in the troposphere. The high correlation with the actual rainfall shows a positive significance of groundbased GPS technology in the monitoring and earlywarning of rainstorms. The results indicate that when higher PWV （>40 mm）continues in Beijing, within 24 to 36 hours there may occur a heavy rainfall; when PWV becomes very rich (increased 10 to 20 mm per hour) with sustainable PWV development in short time, a storm may be coming. The effective application of GPSMET technology in weather forecast can improve the precision and accuracy greatly.
2015, 43(6):1164-1169.
Abstract:
Base on the ECMWF analysis and forecast data (025°×025°), wind profile data, and radiosonde data, the transformation process of raintosnow and then snowtorain in Jiaxing on 18 February 2014 is analyzed. The result shows that the temperature at 850 hPa and 925 hPa declined during the daytime, but the transformation from rain to snow occurred in the morning and that from snow to rain in the afternoon. In the morning, abundant water vapor was lifted to the higher and colder height, and then condensed, forming dense snowflakes; when snowflakes fell, the temperature at lower levels was not high enough for them to melt. While in the afternoon, water vapor mainly existed at the low levels, where temperature was only between -2 ℃ and -3 ℃. Supercooled water droplets instead of snowflakes formed in this environment, and at the same time surface temperature increased up to over 0 ℃ by the effects of warm advection near the ground from the sea, so the precipitation phase transformed from snow to rain.
Base on the ECMWF analysis and forecast data (025°×025°), wind profile data, and radiosonde data, the transformation process of raintosnow and then snowtorain in Jiaxing on 18 February 2014 is analyzed. The result shows that the temperature at 850 hPa and 925 hPa declined during the daytime, but the transformation from rain to snow occurred in the morning and that from snow to rain in the afternoon. In the morning, abundant water vapor was lifted to the higher and colder height, and then condensed, forming dense snowflakes; when snowflakes fell, the temperature at lower levels was not high enough for them to melt. While in the afternoon, water vapor mainly existed at the low levels, where temperature was only between -2 ℃ and -3 ℃. Supercooled water droplets instead of snowflakes formed in this environment, and at the same time surface temperature increased up to over 0 ℃ by the effects of warm advection near the ground from the sea, so the precipitation phase transformed from snow to rain.
2015, 43(6):1170-1175.
Abstract:
The problems of electromagnetic interference caused by lightning strikes are important research topics in the building lightning protection area. The spatial distribution of the magnetic field around elevated subway station is simulated using the finite element method (FEM) when struck by lightning. The method of magnetic field numerical simulation by use of FEM in the IES electromagnetic simulation software is introduced, and taking the Changyang elevated subway station in Fangshan as an example, the distribution of the magnetic field is obtained through the following process: model building, material setting, excitation source applying, mesh generation, postprocessing, etc. Then the spatial distribution of the magnetic field is presented in figures, and the features of the magnetic field are analyzed. The intensity and scope of lightning magnetic interference are determined, and the corresponding protection methods and measures are proposed. Finally, the attenuation of the magnetic field and the safe distance from the equipment to the downconductor are calculated after the shielding measures being taken in the elevated station.
The problems of electromagnetic interference caused by lightning strikes are important research topics in the building lightning protection area. The spatial distribution of the magnetic field around elevated subway station is simulated using the finite element method (FEM) when struck by lightning. The method of magnetic field numerical simulation by use of FEM in the IES electromagnetic simulation software is introduced, and taking the Changyang elevated subway station in Fangshan as an example, the distribution of the magnetic field is obtained through the following process: model building, material setting, excitation source applying, mesh generation, postprocessing, etc. Then the spatial distribution of the magnetic field is presented in figures, and the features of the magnetic field are analyzed. The intensity and scope of lightning magnetic interference are determined, and the corresponding protection methods and measures are proposed. Finally, the attenuation of the magnetic field and the safe distance from the equipment to the downconductor are calculated after the shielding measures being taken in the elevated station.
2015, 43(6):1176-1180.
Abstract:
The UAV (Unmaned Air Vehicle) aerial photography is a combination of UAV technology and photography, and a UAV remote sensing technology realizing through the integration of aircraft technology, communication technology, and GPS differential positioning and image technology. Multirotor UAVs have many advantages, such as lowcost, flexibility, high security, and enabling the detection of highrisk areas. Its maximum flight speed is 60 km/h, maximum climb speed is 60 km/h, and maximum flying height is 3 km. It can easily mount microcamera or SLR camera to perform observation mission. In this study, the UAV aerial photography is applied to lightning protection. After actual testing, it is found that some difficult problems in lightning protection that are unable to complete manually can be solved through the use of UAV aerial photography technology, including the external lightning protection system checking for towers and sloping roof constructions，the investigation of lightning disasters, and the estimation of the sizes of the building structures. The inspection efficiency of lightning protection device in largescale building groups can be greatly improved by UAV applications. It has good prospects in lightning protection and Lightning disaster investigation.
The UAV (Unmaned Air Vehicle) aerial photography is a combination of UAV technology and photography, and a UAV remote sensing technology realizing through the integration of aircraft technology, communication technology, and GPS differential positioning and image technology. Multirotor UAVs have many advantages, such as lowcost, flexibility, high security, and enabling the detection of highrisk areas. Its maximum flight speed is 60 km/h, maximum climb speed is 60 km/h, and maximum flying height is 3 km. It can easily mount microcamera or SLR camera to perform observation mission. In this study, the UAV aerial photography is applied to lightning protection. After actual testing, it is found that some difficult problems in lightning protection that are unable to complete manually can be solved through the use of UAV aerial photography technology, including the external lightning protection system checking for towers and sloping roof constructions，the investigation of lightning disasters, and the estimation of the sizes of the building structures. The inspection efficiency of lightning protection device in largescale building groups can be greatly improved by UAV applications. It has good prospects in lightning protection and Lightning disaster investigation.
2015, 43(6):1181-1185.
Abstract:
According to meteorological observation data during the high temperature season in 2013 and the observation results of microclimate and rice fructification in middleseason rice anthesis, two warming modes of rice community during the high temperature season are concluded: compound warming and radiative warming. Panicle temperature is affected not only by ambient temperature, but also by solar radiation intensity. The higher the rice panicle is, the higher its temperature is, and the temperature of the upper rice panicle is higher than that of its lower part. Through analyzing the synchronous observation data of rice panicle and microclimate in 2013, verified by the observation data in 2008, which are characterized with radiation warming, the time proportion with panicle temperature being ≥35 ℃ in the anthesis period (09:00 to 13:00) for middleseason rice is concluded as a quantitative indicator of the high temperature effect on the percentage of unfilled grains. Even when temperature is <35 ℃, the panicle temperature can also be ≥35 ℃ due to intense solar radiation, which leads to high temperature sterility of rice.
According to meteorological observation data during the high temperature season in 2013 and the observation results of microclimate and rice fructification in middleseason rice anthesis, two warming modes of rice community during the high temperature season are concluded: compound warming and radiative warming. Panicle temperature is affected not only by ambient temperature, but also by solar radiation intensity. The higher the rice panicle is, the higher its temperature is, and the temperature of the upper rice panicle is higher than that of its lower part. Through analyzing the synchronous observation data of rice panicle and microclimate in 2013, verified by the observation data in 2008, which are characterized with radiation warming, the time proportion with panicle temperature being ≥35 ℃ in the anthesis period (09:00 to 13:00) for middleseason rice is concluded as a quantitative indicator of the high temperature effect on the percentage of unfilled grains. Even when temperature is <35 ℃, the panicle temperature can also be ≥35 ℃ due to intense solar radiation, which leads to high temperature sterility of rice.
2015, 43(6):1186-1191.
Abstract:
Based on the phenological data of peony and meteorological data in Heze, the correlation between first flowering dates of peony and meteorological condition is analyzed by using the statistical analysis methods, such as climatic trend rate and MannKendall abrupt change test. The results show that: (1) The first flowering dates of peony show an advanced tendency of 4.4 d/10a, and abrupt changes occurred in 1996. The first flowering date of peony is mainly concentrated in the last ten days of April from 1981 to 1996, while other mainly concentrated in the middle ten days of April in from 1997 to 2010. (2) The dates of peony flowering are mainly depended on the mean temperature of March, and the mutation nodes of first peony flowering dates and March mean temperature are consistent; the influence of February mean temperature is the second, March sunshine has certain influence on the first peony flowering dates; precipitation has no obvious influence. (3) The dates of peony flowering are predicted with the ForcTT model: the optimal beginning date is 1 February; the optimal basic temperature is 1 ℃; the average error is 1.29 days; RMSE is 1.73 days. While the basic temperature is 3 ℃, average error and RMSE are within 2 days, which also verifies that February and March temperature has great influence on the first flowering dates of peony.
Based on the phenological data of peony and meteorological data in Heze, the correlation between first flowering dates of peony and meteorological condition is analyzed by using the statistical analysis methods, such as climatic trend rate and MannKendall abrupt change test. The results show that: (1) The first flowering dates of peony show an advanced tendency of 4.4 d/10a, and abrupt changes occurred in 1996. The first flowering date of peony is mainly concentrated in the last ten days of April from 1981 to 1996, while other mainly concentrated in the middle ten days of April in from 1997 to 2010. (2) The dates of peony flowering are mainly depended on the mean temperature of March, and the mutation nodes of first peony flowering dates and March mean temperature are consistent; the influence of February mean temperature is the second, March sunshine has certain influence on the first peony flowering dates; precipitation has no obvious influence. (3) The dates of peony flowering are predicted with the ForcTT model: the optimal beginning date is 1 February; the optimal basic temperature is 1 ℃; the average error is 1.29 days; RMSE is 1.73 days. While the basic temperature is 3 ℃, average error and RMSE are within 2 days, which also verifies that February and March temperature has great influence on the first flowering dates of peony.
2015, 43(6):1192-1196.
Abstract:
Based on the daily meteorological data in Fuzhou from 1961 to 2012, the monthly human comfortability is analyzed with the torridity index. The results show that: (1) The human comfort index based on daily mean temperature can reflect human sensation in all seasons except summer; however, the human comfort index from maximum temperature can reflect human’s real feeling. (2) The comfort degree can be divided into 5 levels: January to February (cold); March, November, and December (slightly cold); April to June and September (comfort); July to August (a little hot); October (fairly comfort). May is most comfort, January is most cold, and July is the hottest. (3) The comfort index increased obviously during the last 50 years. Although the increase trend of comfort index was not significant, the large values appeared after the late 1990’s. The results indicate that the human comfort degree increased in winter, especially after the late 1980’s.
Based on the daily meteorological data in Fuzhou from 1961 to 2012, the monthly human comfortability is analyzed with the torridity index. The results show that: (1) The human comfort index based on daily mean temperature can reflect human sensation in all seasons except summer; however, the human comfort index from maximum temperature can reflect human’s real feeling. (2) The comfort degree can be divided into 5 levels: January to February (cold); March, November, and December (slightly cold); April to June and September (comfort); July to August (a little hot); October (fairly comfort). May is most comfort, January is most cold, and July is the hottest. (3) The comfort index increased obviously during the last 50 years. Although the increase trend of comfort index was not significant, the large values appeared after the late 1990’s. The results indicate that the human comfort degree increased in winter, especially after the late 1980’s.
2015, 43(6):1197-1202.
Abstract:
Human comfort has a significant impact on people’s work and life, and studies of human comfort under different weather conditions are important in public meteorological service. Using the atmospheric detection technology and means, the temperature and humidity were obtained at three times (07:00,13:30,19:00) a day in four typical observation sites in the Chengdu University of Information Technology from June 2013 to March 2014. The difference of indoor and outdoor human comfort is analyzed under typical cloudy and clear days, and the correlation of indoor and outdoor human comfort is studied by using the temperature and humidity index (THI). The results show: (1) On sunny days, the number of comfortable days is the greatest in the crowded indoor environment, accounting for 61% of the total number of days; on cloudy days, the number of comfortable days is the least in the outdoor environment, constituting 40% of the total number of days. (2) The biggest difference in human comfort under different weather conditions is in summer. On sunny days, the human comfort in small rooms with less people is the best, while outdoor comfort is the worst. However, on cloudy days, outdoor comfort is the best, while the human comfort in big crowded rooms is the worst. (3) On cloudy days, a significant correlation is found in temperature and humidity indexes between less crowded small indoor and outdoor environment, the correlation being the best (〖WTBX〗R2 〖WTBZ〗=0.97), while the correlation is the worst (〖WTBX〗R〖WTBZ〗2=0.92) between large crowded indoor and outdoor temperature and the humidity indexes.
Human comfort has a significant impact on people’s work and life, and studies of human comfort under different weather conditions are important in public meteorological service. Using the atmospheric detection technology and means, the temperature and humidity were obtained at three times (07:00,13:30,19:00) a day in four typical observation sites in the Chengdu University of Information Technology from June 2013 to March 2014. The difference of indoor and outdoor human comfort is analyzed under typical cloudy and clear days, and the correlation of indoor and outdoor human comfort is studied by using the temperature and humidity index (THI). The results show: (1) On sunny days, the number of comfortable days is the greatest in the crowded indoor environment, accounting for 61% of the total number of days; on cloudy days, the number of comfortable days is the least in the outdoor environment, constituting 40% of the total number of days. (2) The biggest difference in human comfort under different weather conditions is in summer. On sunny days, the human comfort in small rooms with less people is the best, while outdoor comfort is the worst. However, on cloudy days, outdoor comfort is the best, while the human comfort in big crowded rooms is the worst. (3) On cloudy days, a significant correlation is found in temperature and humidity indexes between less crowded small indoor and outdoor environment, the correlation being the best (〖WTBX〗R2 〖WTBZ〗=0.97), while the correlation is the worst (〖WTBX〗R〖WTBZ〗2=0.92) between large crowded indoor and outdoor temperature and the humidity indexes.
2015, 43(6):1203-1208.
Abstract:
The rainfall data from the Beijing Meteorological Observatory and Miyun Station in Beijing, which were assumed as representative stations for urban and suburban areas, are used. Based on the minutetominute rainfall observation data from 1961 to 2013, comparison and analysis are made of the different cumulative rainfall in summer, the frequency of rainfall, and the precipitation intensity between urban and suburb areas. Also, using the Gumbel method, which can fit annual maximum to derive the equations of rainstorm intensity for urban and suburb areas, their spatial availabilities are compared. The results indicate that there are obvious characteristics in variations of daily rainfall in Beijing, including the larger proportion of rainfall at night and higher occurrence frequency of rainfall from noon to midnight and greater rainfall amount, frequency, and precipitation intensity during 15:00 to 17:00 in both urban and suburb areas; the total rainfall, shortduration rainfall, and precipitation intensity in summer were greater in the suburb area. However, the intensitydurationfrequency curve shows that the rainfall data of urban stations is inapplicable for suburban stations, and the difference between urban suburb areas should be considered. Different standards should be adopted in the design of the drainage system.
The rainfall data from the Beijing Meteorological Observatory and Miyun Station in Beijing, which were assumed as representative stations for urban and suburban areas, are used. Based on the minutetominute rainfall observation data from 1961 to 2013, comparison and analysis are made of the different cumulative rainfall in summer, the frequency of rainfall, and the precipitation intensity between urban and suburb areas. Also, using the Gumbel method, which can fit annual maximum to derive the equations of rainstorm intensity for urban and suburb areas, their spatial availabilities are compared. The results indicate that there are obvious characteristics in variations of daily rainfall in Beijing, including the larger proportion of rainfall at night and higher occurrence frequency of rainfall from noon to midnight and greater rainfall amount, frequency, and precipitation intensity during 15:00 to 17:00 in both urban and suburb areas; the total rainfall, shortduration rainfall, and precipitation intensity in summer were greater in the suburb area. However, the intensitydurationfrequency curve shows that the rainfall data of urban stations is inapplicable for suburban stations, and the difference between urban suburb areas should be considered. Different standards should be adopted in the design of the drainage system.
32 Meteorological Forecast Model of Daily Maximum Electrical Load in Shanghai Based on Filter Technique
2015, 43(6):1209-1212.
Abstract:
Electrical load is significantly impacted by weather conditions. Therefore, the seasonal variation, holiday effects, weekend effects, and the weather dependency of daily maximum electrical load are investigated by using the daily maximum electrical load data in Shanghai and meteorological observations from the Xujiahui weather station from May 2010 to December 2013. The stepwise regression method and filter technique are employed to build the meteorological forecast model in winter and summer. The model consists of two components: regular change component and weathersensitive component. The results show that the effects of various holidays are different. The Spring Festival has the longest and greatest influence on daily maximum power load. The holiday effect is more pronounced during the first several days of the National Day than in the other days. The weekend effect is greater in summer than in other seasons. The best model is able to explain most of variability in daily maximum electrical load, with the mean prediction relative error less than 5%.
Electrical load is significantly impacted by weather conditions. Therefore, the seasonal variation, holiday effects, weekend effects, and the weather dependency of daily maximum electrical load are investigated by using the daily maximum electrical load data in Shanghai and meteorological observations from the Xujiahui weather station from May 2010 to December 2013. The stepwise regression method and filter technique are employed to build the meteorological forecast model in winter and summer. The model consists of two components: regular change component and weathersensitive component. The results show that the effects of various holidays are different. The Spring Festival has the longest and greatest influence on daily maximum power load. The holiday effect is more pronounced during the first several days of the National Day than in the other days. The weekend effect is greater in summer than in other seasons. The best model is able to explain most of variability in daily maximum electrical load, with the mean prediction relative error less than 5%.
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.
Supported by:Beijing E-Tiller Technology Development Co., Ltd.