Founded in 1973, Meteorological Science and Technology(Bimonthly, ISSN:1671—6345, CN 11—2374/P)is governed by China Meteorological Administration, and jointly sponsored by CMA Meteorological Observation Centre, Chinese Academy of Meteorological Sciences, Beijing Meteorological Service, National Satellite Meteorological Center and National Meteorological Information Centre. As a comprehensive technical journal with engineering features, Meteorological Science and Technology aims to provide a platform for the exchange of knowledge, technology, and experience for scientific and technical personnel. The journal mainly publishes research articles that reflect new theories, methods, and technologies in atmospheric science and related sciences. Main columns include Atmospheric Sounding and Information Technology; Weather & Climate and Numerical Forecasting; Applied Meteorology and Scientific Experiments, and Practical Techniques.

The journal is now indexed by China Science and Technology Journal Database, CNKI Digital Library, Wanfang Data. The journal is also a source journal of A Guide to the Core Journal of China (1992, 1996, 2000, 2008, 2014), China Academic Journal CD-ROM, and Chinese Scientific and Technical Papers and Citations.

Meteorological Science and Technology is an A4-size journal published bimonthly with worldwide distribution. The annual subscription fee is 120 CNY. Readers can subscribe anytime throughout the year. Researchers, professionals, and lecturers engaged in atmospheric science and related disciplines are welcome to submit articles and subscribe to the journal.

  • Current Issue
  • Archive
  • Most Downloaded
  • Browser Ranking
  • Citation Ranking
    Article Search
    Search by issue
    Select AllDeselectExport
    Display Method:
    2023,51(5):613-628, DOI:
    Abstract:
    Monitoring the snow cover on the Qinghai Tibet Plateau holds great significance for climate prediction and snow disaster prediction, among other things. With its high temporal resolution and high spatial resolution, FY-4 data is providing a new field in snow monitoring service by geostationary satellite. Constructing snow monitoring methods and models based on FY-4A not only expands the application field of geostationary satellites but also enriches the means of snow monitoring application. The high temporal resolution of FY-4 provides minute-level data for research on snow monitoring, offering a more detailed understanding of changes in snow cover and clouds. To facilitate application for producers and reference for decision-makers, and to further improve the accuracy of snow depth inversion products, this paper is based on the hourly field snow depth observation data, daily FY-3D_SNC data, and the hourly FY-4A satellite data. A snow identification method based on NDSI (Normalized Difference Snow Index) is being constructed, as well as a snow depth monitoring model. In the end, referring to the existing snow depth classification standards on the Qinghai Tibet Plateau, a classification standard for snow depth levels in shallow snow areas using FY-4 satellite is proposed, based on NDSI and the linear estimation equation of snow depth. Mapping examples of different snow depth levels in plateau areas have been completed to better provide reference for practical business monitoring services and applications. The results show that NDSI≥0.20 is the reasonable threshold for FY-4A satellite snow detection in the Qinghai Tibet Plateau region, with a missing detection rate of less than 8.0% regardless of cloud conditions. The ground station verification results show that the accuracy of snow recognition is over 83.33%. After the cloud is directly removed in the spatial range, the accuracy of snow identification is more than 82.48%, verified by the confusion matrix. Therefore, the FY4 satellite has the ability to monitor snow cover in the Qinghai Tibet Plateau region. Although the FY-4A satellite does not have the ability to distinguish snow depths exceeding 10 cm, it can effectively identify shallow snow depths below 10 cm, with a correlation coefficient of 0.745, passing the 0.001 significance level. As a result, the FY-4A satellite snow depth level index of 0 to 10 cm has been established, with an overall classification accuracy of 87.50%. Hence, the FY-4A satellite snow depth inversion method has good estimation ability for 0 to 10 cm shallow snow depths in the Qinghai Tibet Plateau region.
    2023,51(5):629-638, DOI:
    Abstract:
    Aiming at the problem of uncertainty regarding the threshold parameters in the quality control of radiosonde temperature using the bi-weight standard deviation method, an optimization algorithm for threshold Z parameters based on the skewness and normal waveform indicators is being proposed. By utilizing the temperature data from three radiosonde stations in Fujian in 2017 and the ERA5 model reanalysis temperature data, a comparative analysis of the different datasets of the sounding temperature increment data before and after quality control is conducted. The distribution curve of the kurtosis-skewness value CKS with threshold Z indicates that a higher threshold Z will result in incomplete quality control, while a lower threshold Z will result in excessive quality control. The optimal threshold Z of the bi-weight standard deviation method, as determined by the kurtosis-skewness value CKS, is more consistent with the normal distribution requirements of the model assimilation system than the fixed threshold of the bi-weight standard deviation method. This provides a better method for quality control of radiosonde temperature data in model assimilation. Regarding the distribution characteristics of temperature increment before and after quality control, the temperature observation increment consistently removes outliers from the entire pressure atmosphere using a fixed increment value. Around 57.15% of outliers are primarily distributed in the range of 0-100 hPa, while the remaining 42.85% of outliers are evenly distributed in the range of 100-1000 hPa. The abnormal points, where the absolute value of temperature increment within the range of 0-100 hPa is greater than 10 ℃, are caused by factors such as solar radiation affecting the temperature sensor, which exceed the normal detection error range. These abnormal points can be removed in advance before quality control, further improving the quality of radiosonde temperature data.
    2023,51(5):639-647, DOI:
    Abstract:
    The layout quality of the meteorological station network directly affects the efficiency of observation data use. The existing surface precipitation station network in Sichuan Province is analyzed from the perspectives of the horizontal station spacing, vertical layer distribution, slope, river basin, risk zoning, station control range, and grid coverage, aiming to provide a scientific basis for the subsequent increase or decrease of stations and the optimisation of station network layout. The results show that: (1) The average horizontal station spacing of Sichuan precipitation stations is 9.04 km, which fully meets the requirements for climate monitoring by the World Meteorological Organisation OSCAR, and the “breakthrough” needs of global numerical weather forecasting, but there still exists a certain gap from the ideal “target”. (2) Over 80% of precipitation stations in Sichuan Province are located in low and medium-altitude areas, and 92.38% of precipitation stations are located in flat slopes, relatively flat slopes, gentle slopes, and relatively gentle slopes. (3) The area of the higher and highest-risk areas in Sichuan Province accounts for less than 40%, and the number of stations accounts for more than 50%. The density of the station network gradually increases with the risk area from low to high. (4) Stations with a control area of <100 km2 are primarily distributed in the Sichuan Basin. Stations in the Western Sichuan Plateau generally have a control area of more than 100 km2, and some stations have a control area of more than 1000 km2. (5) The grid coverage at different resolutions is highest in the Sichuan Basin, followed by the Panzhihua Xichang area, and the Western Sichuan Plateau is relatively low.
    2023,51(5):648-657, DOI:
    Abstract:
    Limited by the geographical environment, communication conditions, and personnel support capacity, the scientific investigation data of the Qinghai-Tibet Plateau cannot be collected and transmitted through the existing meteorological communication system. This has been a challenging problem for meteorological researchers. Relying on the public cloud resources of telecom operators, the author has established a scientific research data collection and transmission platform and is carrying out a significant amount of scientific research observation data collection and transmission work in Motuo, Tibet. The platform utilizes a high-concurrency data acquisition and distributed parallel processing framework to achieve continuous and orderly work of data collection, processing, distribution, monitoring, and other applications on a single server. It also provides targeted monitoring and archiving services for data in combination with the characteristics of scientific research instruments. Additionally, the author has designed and implemented a lightweight data upload client to address the data acquisition problem of scientific observation equipment deployed in the field. The platform〖DK〗’s design can be applied to the collection and transmission of scientific observation data in other regions.
    2023,51(5):658-667, DOI:
    Abstract:
    In order to achieve the goal of integrating provincial meteorological service data resources and unifying meteorological service export, promote the efficient application of meteorological data products in disaster prevention and public services, based on the Spring Cloud framework, the Hunan meteorological service platform is developed using Software Plugin, WebSerivce and other technologies. This paper introduces the layered model and functional structure of this platform and the key technologies such as multi-source meteorological data fusion processing, data parallel processing based on microservice, data vectorization based on SVG, and data secure interaction. The platform obtains meteorological data from CMADaas, packages them into the data plugin, graphic plugin and speciality plugin, provides meteorological products such as observation data, forecast, early warning, satellite cloud and Radar images through standard interfaces, and ensures the security of meteorological products service process based on MOID. The meteorological service plugin of this platform has been applied to the application systems of the Hunan Emergency Management Department, Natural Resources Department, Water Resources Department and other units. Application results indicate that the plugin service mode of this platform is suitable for different types of meteorological service needs, such as C/S clients, websites, and mobile apps. It realizes the unified management, efficient processing and standardized application of meteorological services and improves provincial meteorological service capabilities.
    2023,51(5):668-680, DOI:
    Abstract:
    The simulation of the extremely severe rainfall that occurred in Zhengzhou City, Henan Province, on 20 July 2021, is carried out to figure out the effects of topographic height and relief on water vapour transport and vertical conditions using the numerical model. The result shows that the CMA-MESO (GRAPES-MESO 3km) model’s simulation was satisfied with the actual situation for this process. However, the simulated precipitation centre was slightly to the west. The terrain had a significant impact on precipitation. The precipitation centre weakened when the terrain height decreased, and its position leaned toward the north. The precipitation centre strengthened when the terrain height increased, and its position leaned toward the south. The main influence mechanisms are as follows: (1) The upward effect of the Taihang Mountain and the mountain on the west side of Zhengzhou City resulted in a strong vertical ascending movement in the west of Zhengzhou City, and there was a deep convective system. The blocking effect of Funiu Mountain terrain had a significant effect on the north-south position of the vertical movement centre. Under the influence of the two typhoons, the warm and wet air coming from the southeast was formed, and the blocking effect of the southern part of Taihang Mountain caused part of the air in the north branch to deflect to the west and produced a southward component. That conjoined with the southerly airflow over Funiu Mountain and the southern branch of the southeast airflow, transported water vapour to the northwest under the blocking mountains such as Taihang Mountain and Songshan Mountain so that large-scale water vapour convergence was maintained over Zhengzhou City, and extremely heavy rain was generated. (2) With the increase of local height, part of the airflow from the north branch of the southeast airflow was blocked and turned into the northeast airflow, the intensity of the convergence zone of the airflow increased, the vertical velocity centre shifted to the south, and the water vapour content over Zhengzhou increased obviously. The southern branch of the southeast airflow also produced a strong updraft in the southwest of Zhengzhou under the effect of Funiu Mountain and formed two heavy precipitation centres near Zhengzhou, corresponding to Funiu Mountain and Songshan Mountain in the southwest and Taihang Mountain in the northwest, respectively. Under the uniform terrain condition, without the lifting and blocking effect of Taihang Mountain and Songshan Mountain, the water vapour accumulation over Zhengzhou decreased, the vertical movement centre moved northward, and the simulated precipitation centre was weaker than the real terrain condition, and the location was northward.
    2023,51(5):681-692, DOI:
    Abstract:
    Typhoon Hagupit (No.04,2020) caused torrential rainfall in the mountain region as it passed over North Yandang Mountain after making landfall in the south coastal areas of Zhejiang Province. Based on the Weather Research and Forecast (WRF) version 4.0.2 mesoscale numerical model, a high-resolution numerical simulation is conducted on typhoon Hagupit to analyse the effect of North Yandang Mountain on the occurrence of this heavy rainstorm caused by the typhoon. Sensitivity experiments, which involve adjusting the terrain height by lifting or reducing it, are carried out to investigate the role of terrain. The results are as follows: The track and intensity of the typhoon were well simulated by the numerical experiment over time. The simulated torrential rain triggered by the typhoon was consistent with the observation, including the rainfall area and intensity. The distribution of the strong wind centre caused by typhoon Hagupit was noticeably asymmetric. The first and fourth quadrants of typhoon Hagupit successively passed over the mountain region after the typhoon made landfall, which transported sufficient water vapour to the mountain region through a strong southerly jet on the east side of the typhoon. A long and narrow spiralling convergence band was observed at low altitudes above the mountain region, which was brought from the inner core of typhoon Hagupit before the landfall. The location and distribution of the water vapour flux convergence band were consistent with the wind convergence band. Strong upward motion occurred on the windward slope along the heavy rain centres when the eyewall of the typhoon passed over, indicating favourable dynamic conditions for the formation of torrential rain. The water vapour transport band extended upward from the near surface into the lower atmosphere, and scattered convective cells started to be triggered and enhance in the mountain region simultaneously. As the back of typhoon Hagupit passed over, the winds weakened in the high altitude area of the mountain region, resulting in flow around and the formation of mesoscale vortices, which contributed to the heavy rainstorm. The primary reason for the appearance of torrential rainfall was the presence of a strong, persistent, and fixed positive vorticity centre on the windward slope of the heavy rain centre. In sensitive experiments involving the terrain height, it was observed that the accumulated precipitation decreased by 40% to 50% when the terrain height in North Yandang Mountain was set to zero, while it increased by over 60% when the terrain height was doubled in the mountain region.
    2023,51(5):693-703, DOI:
    Abstract:
    The weather system on 600 hPa can analyse the main characteristics of the variation of low vortex over the western Sichuan Plateau and identify the relationship between the development and movement of low vortex and the heavy precipitation area over the western Sichuan Plateau. Therefore, we are currently analyzing the spatiotemporal distribution of the vortex on 600 hPa, the relationship between low vortex and precipitation, and dynamic and thermal characteristics of vortex causing rainfall in the western Sichuan Plateau in the summer half of the year by using the 3-hour ERA5 reanalysis data (0.25°×0.25°) and the hourly precipitation data from 2011 to 2020. The results show that there are 80 low vortices per year in 42 years, and the duration of less than one day accounts for 95.7% of the total. The formation and extinction of the low vortices are affected by the topography on the east side of the plateau and the obvious diurnal variation of surface temperature. The annual average number of the low vortices generated in the western Sichuan Plateau is 61.5. The annual average number of the low vortices which move in the western Sichuan Plateau is 18. And the annual average number of the low vortices which move out of the western Sichuan Plateau is 5.3. The source area of the low vortex is located in Baiyu County in Ganzi Prefecture. And the dissipation area of the low vortex is located in Litang County in Ganzi Prefecture. The low vortices with a life history longer than 12 h account for 36.4%,which will bring precipitation. And more than 83.7% of them will cause moderate rainfall or above. The central position of the maximum daily precipitation intensity associated with the low vortex moves from the eastern and southern parts of the western Sichuan Plateau to the central part each month, and then gradually moves back to the eastern and southern parts. Correspondingly, in July and August, majority low vortices move from the north and south to the centre and wobble away. In other months, majority low vortices formed in the centre will affect the east and south areas, or generated in the south and then stagnate or wobble in situ. Strong vertical upward motion, the coupling development of positive vorticity region and the formation and maintenance of the deep unstable stratification are the dynamic characteristics and thermodynamic stratification conditions of the generation and development of vortex, causing heavy precipitation.
    2023,51(5):704-714, DOI:
    Abstract:
    Based on conventional observation data, dual-polarisation radar data, and raindrop spectrometer data, different phases of rain, sleet, and pure snow caused by a rare cold wave that occurred in Changzhou on 28 March 2020 are analyzed. The results show that: (1) The impact of this intense cold wave weather happened in the winter and spring alternating season at the end of March. There was a severe drop in cooling weather in Changzhou (the temperate drop in early spring ranked second in history), and light rain, light sleet, or light snow occurred successively. During the cold wave, the temperature fell sharply twice. The first drop (8.7 ℃ in 6 h) was caused by the weak cold air at the surface. The second cooling period (2 h drop of 5.0 ℃ during this time) occurred primarily due to a combination of high altitude trough, mid to low-level shear, and surface cold high pressure, as well as strong cold advection intrusion and the absorption of evaporative (or sublimative) heat by an apparent dry layer at 850 hPa. This triggered a sharp decrease in temperature at the mid and low levels during precipitation, causing the entire layer to become a cold layer and remained low. This provided favourable conditions for the rain to turn into snow, resulting in rapid changes in the precipitation phase. (2) The dual-polarisation radar determined that the three precipitation phases displayed different polarisation variable characteristics. When the precipitation phase changed to sleet, Z increased, ZDR increased significantly, CC showed an evident low-value zonal distribution, and KDP increased slightly. During the transition from sleet to pure snow, the mixed region of rain and snow phase composed of Z>30 dBz, ZDR>1 dB, CC<0.95 was gradually pressured south, and then became Z>22 dBz, ZDR<1 dB,CC>0.98 pure snow, and KDP decreased slightly. It was also observed that dual-polarisation radar had more reference significance for monitoring precipitation in different phase states than single polarisation radar. (3) The rain phase consisted of high-concentration small particles and low-concentration large particles. The raindrop speed-scale spectrum presented a slanted band, which conformed to the Brandes experience curve, characterised by a large falling velocity and small particle diameter. In the stage of sleet, the number concentration decreased, the particle size range broadened, Dm increased significantly, and the maximum diameter approached 6 mm. The range of raindrop velocity and particle size fell between rain and pure snow. In the pure snow stage, at the beginning of the snow, the snow intensity was small, and the number concentration decreased significantly. As the snow intensity increased, the number concentration increased, nearing 2.2 m-3mm-1. The spectral width of particles widened rapidly, and there were more large particles. The concentration of small particles was larger, whilst the concentration of large particles was smaller.
    2023,51(5):715-727, DOI:
    Abstract:
    The urban heat island effect is one of the primary manifestations of the impact of human activities on the atmospheric system. In this paper, the Space and Time Multiscale Analysis System (STMAS) is used to fuse multi-source high spatial and temporal resolution observations from automatic ground stations, radars, satellites and other sources, and establish a three-dimensional data set of urban heat island. Moreover, on this basis, the characteristics of the intensity change of Beijing urban heat island are statistically analyzed, and a case of an ultrastrong urban heat island (June 11-12, 2021) is selected to analyze its three-dimensional fine structure characteristics in detail. The results show that: (1) In the case of the heat island, the suburban near-surfaces cooled rapidly at night, forming an inversion layer, while the temperature of the urban near-surface decreased slowly, which made the temperature difference between suburban and urban near-surface increased continuously. (2) The warm core structure of the three-dimensional temperature field of this ultrastrong urban heat island was clearly visible in the isobaric surface on the ground and near ground isobaric surfaces below 990 hPa. The wind field anomaly showed the characteristics of cyclonic circulation. It converged from suburb to urban area at low height, causing upward movement that could reach middle and high heights, indicating that the urban heat island effect could enhance the vertical circulation.
    2023,51(5):728-737, DOI:
    Abstract:
    With the economic and social development of Shihezi, especially the continuous advancement of industrialization, the pollution weather caused by the haze weather in Shihezi occurs frequently in winter. The heavy pollution weather caused by the haze in winter in 2019 has exceeded 50 days, and the ambient air quality has been deteriorating. In this paper, an analysis is made to investigate the impact of artificial smog dispersal in Shihezi, north of Tianshan Mountain, using the data of extinction coefficient observed by the aerosol lidar in Shihezi in December 2019. The methods mainly adopt the physical statistical test method of weather modification, such as the sign test, pairwise rank sum test of inspection, nonparametric tests, and parametric t-test. The smog reduction effect is obtained based on the extinction coefficient of aerosol lidar. In addition, the ground station monitoring cannot obtain the vertical distribution characteristics and evolution law of pollution. At present, most scholars use aerosol lidar to fill this monitoring gap and realize three-dimensional monitoring of the pollution process. The results are as follows: 20 minutes after the artificial smog dispersal operation, the reliability of the reduction of the average extinction coefficient at different heights below 400 m is 99.5%. Further, according to the 95% confidence threshold, the reduction value is 0.05, and the reduction rate is 9.8%. The reliability of the positive effect obtained by the pairwise rank sum test is 97.5%, which is very significant. However, the reliability of the positive effect obtained by the parametric t-test is only 90% to 80%, which does not reach the threshold of 99.5%, indicating a general significance. This is related to the fact that different types of catalysts are used in operation, such as only hygroscopic dry powder catalyst, and that the variation effect of extinction coefficient as samples cannot meet the test efficiency due to the high seeding height. Further analysis shows that the response effect of reducing the extinction coefficient at different heights below 400 meters decreases from top to bottom 20 minutes after the aircraft〖DK〗’s manual haze reduction operation, which is consistent with the gradual response process of the physical mechanism of the catalyst effect that artificially affects the operation seeding from top to bottom. In China, meteorologists have used weather modification to improve the quality of ambient air. In terms of this paper, the weather modification technology is used to carry out the winter haze reduction test in Shihezi. In the course of the test, the extinction coefficient detected by aerosol lidar is utilized to preliminarily analyze the test effect, which is the first time in China.
    2023,51(5):738-746, DOI:
    Abstract:
    The occurrence process of flood disasters has a certain degree of predictability. Predictive analysis of flood risk can mitigate or reduce the impact of disasters and improve disaster prevention and reduction capabilities. The analysis of flood hazard warning is an important foundation for disaster prevention and reduction. Early warning before the occurrence of disasters can effectively reduce the impact of disasters. The research is focused on flood disasters in the Yangtze River-Huaihe River basin during June to August 2020. This paper aims to develop an improved flood hazard risk warning analysis model using the Analytic Hierarchy Process (AHP) and multiple triggering and predisposing factors. Triggering factors, including cumulative precipitation in the previous three days, current soil moisture, and forecasted precipitation, are crucial in assessing the immediate risks of flood disasters. Predisposing factors, such as river network density, terrain elevation, terrain amplitude, and land use data, provide insights into the vulnerability of the region to flood disasters. By combining these factors, we can effectively evaluate the flood risk and issue timely warnings to mitigate the impact of disasters. To validate the effectiveness of the proposed model, we compare the evaluation results with the flood disaster information reported in the “Meteorological Disaster Management System” of the China Meteorological Administration. The evaluation accuracy rate, which measures the agreement between the risk assessment and the actual occurrence of disasters, reaches 74.46%. This indicates that the model has a relatively high accuracy in predicting flood risks. Additionally, the missing rate, which measures the proportion of missed warnings, is only 5.59%, demonstrating the model’s ability to effectively capture potential flood disasters. Furthermore, the evaluation results show a good correlation between the risk assessment and the actual occurrence of disasters. The warning rate of the maximum disaster unit index, which represents the highest risk within a county, reaches 81.6%. Moreover, for “extreme” heavy rain and flood disasters, the warning rate exceeds 77.3%. This suggests that the proposed model is particularly effective in predicting and warning against severe flood disasters. In terms of temporal consistency evaluation, the risk index consistently increases 3-5 days before the occurrence of “extreme” heavy rain and flood disasters. In conclusion, the model’s high accuracy and reliability make it a valuable tool for decision-making in disaster prevention and reduction efforts. By providing timely and accurate warnings, the model can significantly mitigate the impact of flood disasters and improve the region’s resilience to such events. Future research can focus on further refining the model and incorporating additional factors to enhance its predictive capabilities.
    2023,51(5):747-754, DOI:
    Abstract:
    Lightning disasters are now recognised as one of the top ten most severe natural calamities, being particularly frequent in mountainous areas. The continuous growth of tourism has led to significant impacts on tourists and cable cars, especially in mountainous scenic areas, where equipment like cable cars are highly sensitive to lightning. To investigate the key factors influencing lightning development in these regions and to promptly understand the trends in lightning activity in and around the Huangshan Scenic Area, we are leveraging multiple monitoring data, such as Doppler weather radar, meteorological soundings, and lightning detection. In this study, we are building and evaluating multiple lightning nowcasting models using different machine learning algorithms. The models are based on the non-inductive charging mechanism in the thunderstorm and the characteristics of Doppler weather radar echo. We are extracting echo characteristics of the Doppler weather radar as key forecasting factors, focusing on the intensity, vigour, and movement trends of the thunderstorm system. By comparing false alarm rates, missed alarm rates, and TS scores of various machine learning algorithms, we are selecting the most suitable forecast method for mountainous scenic areas. Our evaluation results reveal that the Random Forest (RF), Logistic Regression (LR), K-Nearest Neighbour (KNN), Gaussian Naive Bayes (GNB), and Support Vector Machine (SVM) algorithms all have certain nowcasting capabilities for lightning. The RF algorithm scores highest in TS scoring, the SVM has the lowest missed alarm rate, and LR has the lowest false alarm rate. Among these, the intensity and vigorous development of the thunderstorm system play a pivotal role in the RF algorithm, with the radar base reflectivity at the -20 ℃ layer height in the thunderstorm system intensity having the most influence, followed by the radar echo thickness above the 0 ℃ layer. Taking an example on 29 August 2021, when a large-scale intense thunderstorm occurred in and around the Huangshan Scenic Area in the afternoon. Employing the RF method resulted in a false alarm rate of 0.425, a missed alarm rate of 0.378, and a TS score of 0.426, indicating good forecasting performance in the area.
    2023,51(5):755-763, DOI:
    Abstract:
    Lightning protection is a measure taken to prevent and reduce material losses and loss of life or personal injury caused by lightning strikes. Lightning protection facilities are easily affected by the external environment and their decreasing performance. Therefore, it is of great significance to evaluate the protection ability of lightning protection measures scientifically to ensure and improve the protection effect. The advantages and disadvantages of fault tree analysis, Bayesian network evaluation, neural network, failure mode analysis, Kent score, and principal component analysis are discussed. Based on the characteristics of coupling and fuzziness of lightning protection measures and the requirement of reasonably determining evaluation index weight, the fuzzy comprehensive evaluation based on improved analytic hierarchy process is proposed. According to the relevant technical standards and norms of lightning protection, considering the impact of the lightning environment, carrier characteristics, and natural factors, an evaluation index system of lightning protection capability with 6 primary indexes and 17 secondary indexes is established. The weights of each index are calculated by establishing a comparison matrix, calculating importance ranking index, constructing a judgment matrix, calculating a transfer matrix, constructing an optimal transfer matrix, calculating a quasi-optimal consistent matrix, solving the feature vector, and so on. The evaluation set and membership matrix of fuzzy comprehensive evaluation are established, and the single index fuzzy evaluation is carried out by using the weight vector and membership matrix corresponding to the evaluation level. The multi-index fuzzy comprehensive evaluation is carried out by using a new matrix composed of a single index evaluation vector and an index weight vector. The evaluation grade of lightning protection capability is determined by the principle of maximum membership degree. This method is used to evaluate the lightning protection ability of the oil and gas gathering station library containing an inflammable and explosive production area, information control function area, and power system function area. The evaluation level is consistent with the actual situation and related literature cases, indicating the applicability and correctness of the method, and providing guidance for the improvement of lightning protection measures and lightning protection ability.
    2023,51(5):764-770, DOI:
    Abstract:
    Based on the observation data of the open-circuit CH4 gas analyzer at Shouxian National Climatological Observatory, we analyze the variation characteristics and influencing factors of CH4 flux in different growth periods of rice-wheat rotation farmland in the Huaihe River Basin. The results show that CH4 flux in the Huaihe River Basin has a single peak distribution throughout the year, with the peak occurring in summer. The diurnal variation of CH4 flux shows a single peak during the day, and the peaks mostly appear in the afternoon. CH4 flux during the day is higher than at night. CH4 flux in the rice growth period is significantly higher than that in the wheat growth period. During the wheat growth period, CH4 flux is the smallest during the seedling period but the largest during the mature period, reaching 0.14 μg m-2s-1. During the rice growth period, the maximum CH4 flux during the jointing period is 3.02 μg m-2s-1, and the minimum during the maturity stage is 0.12 μg m-2s-1. CH4 flux decreases by 50% and 30% before and after the harvest of rice and wheat. This study shows that crop biomass has a significant impact on CH4 flux. CH4 flux is positively correlated with precipitation, relative humidity, water vapour pressure, soil temperature, and air temperature. When precipitation, humidity, or air temperature is higher, the CH4 flux will be greater.
    Article Search
    Search by issue
    Select AllDeselectExport
    Display Method:
    2020,48(6):917-922, DOI:
    [Abstract] (686) [HTML] (0) [PDF 1.07 M] (33525)
    Abstract:
    Using the meteorological observation data of Yuepuhu in Xinjiang from 1981 to 2019, combined with the growth and development of Flos Lonicerae, the relationship between the climatic conditions and the growth of Flos Lonicerae in Yuepuhu are analyzed. According to the ecological characteristics of Flos Lonicerae, the meteorological conditions of Flos Lonicerae cultivation in Yuepuhu are systematically analyzed, and the results show that the average temperature of each phenological stage of Flos Lonicerae in Yuepuhu show an obvious increasing trend; the number of sunshine hours has an obvious increasing trend; and the water source is sufficient. These are conducive to the normal growth and development of Flos Lonicerae. As the temperature rises and the number of sunshine hours increases, the planting time has been advanced from the previous mid March to early March; the planting area has expanded year by year, from tens of hectares in 2016 to 345 hm2 in 2019; and the planting mode has been adjusted from the plain cropping to inter cropping method. In the inter planting mode, the varieties are unified with Beihua No.1. The number of consecutive high temperature days of ≥38 ℃ during the growth and development of Flos Lonicerae, especially in ≥40 ℃ high temperature weather, the short term heavy precipitation weather, windy and sandy weather and other meteorological conditions have certain influence on the quality and yield of Flos Lonicerae. Exploration of the favorable climatic conditions for the development of the Flos Lonicerae planting industry in Yuepuhu provides a scientific basis for the construction of the Yuepuhu Flos Lonicerae industrial base, as well as the meteorological guarantee for the increase of income of flower farmers.
    2021,49(1):55-62, DOI:
    [Abstract] (574) [HTML] (0) [PDF 11.58 M] (32100)
    Abstract:
    Clouds are an important part of the earth system, which can affect the radiation balance of the earth atmosphere system by affecting atmospheric radiation transmission. At present, the information obtained from three dimensional cloud observation has certain limitations, so it is necessary to obtain more accurate three dimensional cloud information by using multi source observation data merging analysis. Based on the successive correction method, 〖JP2〗the Three Dimensional Cloud Merge Analysis Operation System (3DCloudA V1.0) integrates multi source data such as numerical forecast products, geostationary meteorological satellite observation, meteorological radar observation to produce the real time 0.05°/h three dimensional cloud merging analysis product covering China and its surrounding areas (0°-60°N, 70°-140°E), which is distributed to the national and provincial meteorological departments through the China Telecommunication System. The modular system framework is considered in the operation system design and construction process, and the fault tolerant functions such as EC Flow scheduling process real time monitoring and automatic restarting are developed, which effectively improves the stability and reliability of the operation system. Evaluations show that through merging multi source observation data, the three dimensional cloud merge analysis product can describe cloud the top, inside and bottom information more accurately.〖JP〗
    2014,42(5):823-831, DOI:
    [Abstract] (1392) [HTML] (0) [PDF 2.17 M] (29636)
    Abstract:
    In order to improve the weather forecast quality over the low latitude plateau regions, the wind data retrieved with VAD (Velocity Azimuth Display) method are assimilated to the WRF (Weather Research and Forecasting) model by WRF 3DVar (3 Dimensional Variational Data Assimilation System). With different assimilation schemes, a torrential rain event occurred in Yunnan Province from 00:00UTC 30 June 2009 to 00:00UTC 1 July 2009 is numerically simulated and comparatively analyzed. The results indicate that the initial wind fields of the WRF model are markedly improved by assimilating the retrieved wind data. The WRF 3DVar can availably introduce the information of the retrieved wind to the initial conditions of the regional numerical model. The assimilation of the retrieved wind data helps enhance the wind convergence and vapor transportation over the rainy area. Furthermore, the assimilation help improve quantitative precipitation forecasts. The quantitative test of the 18 hour rainfall forecast shows that forecasts are more accurate, less pretermissions, and more rational pertinence for over 250 mm precipitation in the assimilation experimentations. The higher the assimilation frequency and the longer the assimilation time is, the more obvious the influence of data assimilation on the initial fields and forecast fields of the regional model is. But long assimilation time may increase the speed of synoptic systems and the overestimate rainfall, and so the suitable selection of frequency and time is crucial in numerical experimentations.
    2013,41(4):758-763, DOI:
    [Abstract] (1841) [HTML] (0) [PDF 26.87 M] (28331)
    Abstract:
    Through investigating the lightning disasters of ancient buildings, the distribution of ancient buildings being stricken by lightning are analyzed. It is found that animal finials and prominent parts of the like, old trees, towers and kiosks, service facilities and other parts of ancient buildings are vulnerable to lightning strikes. It is found that once an ancient building is stricken by lightning, it is probable to be stricken again by lightning. The reasons for that ancient buildings are stricken and caught fire by lightning are analyzed, and the proportions of casualties caused by ancient building lightning disasters are calculated. It is concluded that the reasons for ancient buildings stricken by lightning includes the appropriate location and structure of ancient buildings, tree triggering, internal environment changes, and water infiltration because of disrepair and other factors vulnerable to lightning.
    2017,45(6):1116-1124, DOI:
    [Abstract] (1068) [HTML] (0) [PDF 2.65 M] (26880)
    Abstract:
    Data quality assessment is an important part in model operation application. In this paper, the soil moisture observation data and China Meteorological Administration Land Data Assimilation System (CLDAS) data are used to establish the online CLDAS data quality assessment system through the MySQL database and the Web technology like html, JavaScript, HighChart, etc. The assessment analysis between the simulated soil moisture and the observed soil moisture at any of stations and provinces, times and different soil layers is implemented in the form of correlation coefficient, root mean square error, relative deviation, and mean deviation. Diagrams such as time series and scatter are visually displayed to compare the observation and simulated data in the system. The statistical indexes can be calculated immediately using JavaScript language in the Web platform. The assessment results and the comparison diagrams can be showed through the internet Web page, and the real time monitoring of the model product data quality can be achieved.
    2013,41(1):15-19, DOI:
    [Abstract] (2245) [HTML] (0) [PDF 12.84 M] (23015)
    Abstract:
    Due to the influence of the curve Earth, the fixed detection mode of the CINRAD/SA weather radar uses the minimum elevation angle of 0.5 °, so the blind area is relatively big, and the detection capability for low level precipitation echoes is limited. On the basis of experiments, the calculation formulas of the minimum height applicable when CINRAD/SA detects with positive and negative elevation angles are devised. Then the minimum detecting heights of CINRAD/SA at different distances with different elevation angles (0.5°, 0°, -0.3°,-0.5°) are calculated. Through analyzing characteristics of radar products detected under different elevation angles, some suggestions on CINRAD/SA about using negative elevation angles are presented.
    2010,38(3):289-294, DOI:
    [Abstract] (2549) [HTML] (0) [PDF 63.01 M] (21837)
    Abstract:
    With the intensive observation data and NCEP/NCAR reanalyzed data, an unusual heavy fog process occurred over the east central China from 25 to 27 December in 2006 is analyzed in aspects of the large scale synoptic condition and dynamic and thermodynamic mechanisms. It was shown that the fog occurred while the near ground wind velocity varied from 0.3 to 2.9 m/s and the dense fog occurred while the wind velocity varied from 0.3 to 2.4 m/s and the visibility was within 15 meters when velocity was from 0.8 to 1.1 m/s. Although vapor condition was bad and rainfall didn’t occur within a few days before the heavy fog, the continuous vapor transportation of the southwestern air current before a trough offered plentiful vapor for the fog. The results also show that the stable stratification gradually established before the fog.At first, the instable stratification built at higher levels after sunrise, subsequently passed downward to lower levels, and then the inversion layer destroyed and the fog dispersed and cleared off. The results indicate that the visibility changed rapidly and violently before the first stage of the severe heavy fog but it did not before the second stage.
    2010,38(3):281-288, DOI:
    [Abstract] (2103) [HTML] (0) [PDF 57.54 M] (20684)
    Abstract:
    In order to reveal the development mechanisms of heavy snowfall in Hebei Province,two heave snow processes on 14 to 16 March 2003 and 20 to 21 February 2004 are selected. A contrast analysis of their meteorological characteristics is made from aspect of synoptic situation and physical mechanism by means of numerical diagnosis with the NCEP reanalysis data and conventional observation data. The results show that the combination of south and north troughs with identical phase around 110°E at 500 hPa, the allocation of the surface pressure field with high in north and low in south, and the appearance of the ground inverted trough in the Hetao area of NW China, as well as the thermodynamic conditions with warm temperature tongue and warm advection in the lower troposphere, are the favorable large scale background for the formation of heavy snowfall. There are three important paths of water vapor in the two snow events: from southwest in front of the 500 hPa trough, from east at low level, and from low level jet. From the cross sections of vorticity, divergence, vertical velocity and vertical helicity, it is found that the vertical distribution of convergence at low level but divergence at upper level and ascending motion in the whole troposphere benefit the forming and maintaining of heavy snowfall, and the distribution of positive vorticity (vertical helicity) in the whole troposphere is most favorable. It is also suggested the temperature descending to below 0 ℃ at both 850 hPa and 925 hPa, meanwhile below 1 ℃ in the surface, is favorable to snowing. The results can be used as reference in the forecasting heavy snowfall.
    2010,38(4):432-436, DOI:
    [Abstract] (1954) [HTML] (0) [PDF 13.24 M] (16026)
    Abstract:
    A whole province range thunderstorm occurred in Zhejiang Province on 26 June 2009, and the occurrence frequency of cloud to ground lightning in this thunderstorm is the highest since the establishment of the lightning position system in 2006. By means of the observation data from the lightning position system, the intensive rainfall observation system, and Doppler radar, the characteristics of the cloud to ground lightning process are analyzed. The results indicate that lightning strokes were mainly negative; in the lightning echo image, negative strokes were mostly distributed in the area of 25 dBz to 55 dBz, and positive strokes were usually in the area of 25 dBz to 35 dBz; lightning strokes occurred mostly on the side of echo development or advancement, distributed around the area with maximum gradients, and there seldom appeared lightning strokes around a strong echo center; the frequency of cloud to ground lightning was correlated closely with the accumulated precipitation of the whole province during the thunderstorm. The peak value of precipitation lagged more than 0.5 hour behind the peak value of the frequency of cloud to ground lightning, and the accumulated precipitation of the whole province occurred 1 to 2 hours behind the peak value of the frequency of cloud to ground lightning. Therefore, the cloud to ground lightning data can be used as a basis in short range severe precipitation forecasting.
    2009,37(1):67-73, DOI:
    [Abstract] (2425) [HTML] (0) [PDF 788.79 K] (14253)
    Abstract:
    Soil moisture is a key variable in water and energy exchanges in land atmosphere interface. The passive microwave remote sensing is the most potent technology to retrieve soil moisture. A brief introduction is made to microwave theory, and a general review of soil moisture retrieval algorithms is given. Three typical cases are illustrated based on the different microwave sensors by comparing various algorithms, which correspond to the three parameter AMSR based retrieval developed by Njoku and Li, the two parameter SMMR based retrieval developed by Owe et al. and the two parameter SSM/I based retrieval developed by Wen et al. The insufficiency and potentials in the researches on soil moisture are discussed.
    2013,41(3):506-515, DOI:
    [Abstract] (1546) [HTML] (0) [PDF 18.37 M] (13145)
    Abstract:
    By using ADAS (ARPS Data Analysis System) and NCEP GFS data as the background field, an assimilation experiment is conducted on CB\\CC Doppler radar reflectivity in Northwest China, and by means of WRF (Weather Research and Forecasting Model), a weather process occurred around the Hetao region of Yellow River and Hebei Province is simulated. The contrast between the experiment results using different simulation schemes and the forecasting verification show that: (1) the introducing of the C Band radar reflectivity data is complementary in space with the S Band radar data, and the rainfall field and vertical structure information given by the complex cloud analysis scheme with satellite and surface observation data are closer to reality. (2) The scheme with C Band radar reflectivity assimilated is superior to the unassimilated for the simulation of the reflectivity echoes, but the simulated system is gradually ebbed because of the inadequate water supply, which is different from reality. (3) The contrast between different assimilation schemes with the real precipitation indicates that the assimilated reflectivities improved the short time precipitation forecast.
    2010,38(4):456-462, DOI:
    [Abstract] (2165) [HTML] (0) [PDF 21.77 M] (12837)
    Abstract:
    The variation features of GPS retrieved atmospheric Precipitable Water Vapor (PWV) are analyzed, and a comparison is conducted on the radiosonde observations and the retrieved precipitation (PWV) in Yunnan. The results show that PWV can be used to reflect the seasonal characteristics of precipitation, and the values of PWV from lower elevation stations are generally higher than those of higher elevation stations in the same period; the changing trends of PWV and radiosonde observations are basically the same, and the correlation coefficient is approximately 0.89; the variation periods of PWV and precipitation are also identical, with the precipitation starting mostly following the peak after a consecutive increasing of PWV; the large increasing amplitude (or keeping at high level) of PWV can be used as an indicator for forecasting continuous heavy precipitation, but when the peak value of PWV is used as a forecasting indicator, seasonal factors should be considered also.
    2013,41(4):696-702, DOI:
    [Abstract] (1498) [HTML] (0) [PDF 10.65 M] (12630)
    Abstract:
    Two coastal heavy rain events occurred in 4-5 and 21-22 August 2010 were caused by the subtropical high. For several kinds of numerical products that are used widely, verification is conducted mainly from the aspects of circulation situation, influencing systems, and precipitation elements. The results show that these numerical products have certain prediction capability for heavy rainfall quantitatively, but predicted rainfall levels are generally smaller, and the prediction of the strong precipitation center is poor in stability; the position forecasts of EC and T639 models are more accurate, but the intensity forecasts are smaller than the actual situation. There are certain differences between numerical models and the actual situation in the position and intensity of the weather systems producing the heavy rainfall. As for the West Pacific subtropical high, the 72 h forecast of the T639 model is weaker than the actual storm, and the stability of EC model is higher, but there is certain deviation in upper trough and shear line forecasts. In torrential rain forecasting, it is necessary, on the basis of numerical forecast products, to combine strong convective products with such auxiliary tools as intensive observation data, physical fields, similar examples, experienced empirical extrapolation, etc., to improve the forecast accuracy of heavy rain forecasts.
    2016,44(5):816-821, DOI:
    [Abstract] (1324) [HTML] (0) [PDF 1.77 M] (12196)
    Abstract:
    Aiming at the problems of safety shot chart mapping, the automatic cartographic algorithm is proposed, which is based on spatial reference, spatial analysis, cartographic expression. According to the location of the station,the accurate space reference coordinate system is adopted. Distance circles and azimuth rays are generated by analysis tools, and the generative process of the safety shot sector zone is derived from the set theory. On account of derivation results,the tools such as SymDiff_analysis, FeatureToPolygon_management, and SelectLayerByLocation_management were integrated to the completed spatial analysis process.The application shows that users just need input the related data,and the drawing process is without human computer interaction, which can guarantee the accuracy of the drawing elements and put an end to the possibility of leakage.
    2010,38(1):49-52, DOI:
    [Abstract] (2392) [HTML] (0) [PDF 24.55 M] (11931)
    Abstract:
    A large scale haze process happened on 12 to 13 December 2008 over Jiangxi Province is analyzed comprehensively based on the air pollution index, conventional observation, and radiosonde data. The results show that the joint influence of the southward moving cold air induced by the vertically turning horizontal trough and the dry warm tongue in the middle level layer is the background cause of the haze process. The cold air could not invade the high level layer above 700 hPa rapidly because of the restraining effect of the dry warm tongue, and then there appeared a “temperature inversion” structure, which facilitated the formation and maintenance of the large scale haze process. Affected jointly by the diurnal temperature difference and the cold air, with a relative low humidity, the weather changed frequently between haze and light fogs. A lower height of mixing layer made the pollutants move horizontally and spread along the mountains, and consequently turned the haze area into a east west pattern from a north south pattern.
    2003,31(1):33, DOI:
    [Abstract] (2145) [HTML] (0) [PDF 135.43 K] (11657)
    Abstract:
    The different values of standard temperature year average using the meteorological data in Anhui Province are discussed. The statistical test of these differences of element average is made on the supposition that standard square deviation for whole data is unknown.The current year average based on 1960-1990 data for China meteorological operation is suitable to the statistical analysis.
    2010,38(3):394-398, DOI:
    [Abstract] (1988) [HTML] (0) [PDF 18.61 M] (11169)
    Abstract:
    The characteristics of benefit assessment of major meteorological disaster service are analyzed. The benefit assessment models, indexes, and working flow are constructed, and a comprehensive assessment is conducted in aspects of weather forecast accuracy, forecasting service coverage, feedback from government decision making departments, and overall assessment of service benefits, and so on. The system is based on the Asp.Net platform and B/S (Browser/Server) structure of. Taking the low temperature and snow/freeze disaster of 2008 as an example, an operation application assessment is carried out with the system, which proved a useful tool for evaluating the benefits of major meteorological disaster service.
    2013,41(6):1101-1108, DOI:
    [Abstract] (1459) [HTML] (0) [PDF 24.45 M] (11134)
    Abstract:
    The characteristics of Radar echoes during the heavy rainfall event from 9 to 16 July 2010 along the Yangtze River in Anhui are analyzed on the basis of conventional meteorological data and Doppler radar data of Hefe Station. It is concluded that the favorable larger scale circulation,ample water vapor, and stronger ascending movement are the advantageous weather background for the severe rainfall. The results show that the source regions of heavy rainfall along the Yangze River in Anhui are often in the Dabie Mountains. The formation and development of radar echoes during heavy rains are always related with the local strong convergence in wind field (adverse wind regions). Heavy rainfall events are prone to happen when rainbelts are combined along the low level shear line and then strengthened, and when single echoes move in the same direction with the larger scale rainbelt area slowly or quasi stationarily.
    2011,39(2):160-164, DOI:
    [Abstract] (2261) [HTML] (0) [PDF 3.88 M] (10894)
    Abstract:
    By using the daily precipitation data from 71 stations in Anhui province from 1961 to 2008, the precipitation amount and frequency of annual heavy rainfall are calculated for every station, and then the climatic characteristics of heavy rainfall over Anhui Province are analyzed by such methods as trend analysis, EOF, power spectrum analysis, wavelet analysis, Mann Kendall test, and so on. The results show that the distribution of heavy rainfall from 1971 to 2000, in accordance with the distribution of the frequency, shows a latitudinal pattern; the high amount and frequency of heavy rainfall appeared mostly around the end of June and the beginning of July. The heavy rainfall in most parts of Anhui had an increase trend, with the high value areas in the western Huaibei and the southern Jiangnan regions. The values of first mode of EOF were positive in all the province, with high values in the southwest of Anhui. The second mode of EOF indicates that the distributions of heavy rainfall in the South and North are contrary, greater in the North and less in the south. The third mode of EOF indicates that heavy rainfall was greater in both South and North, and less in the central part. There were periodic variations with the main periods being 9 to 10 years and the secondary period of about 3 years. The heavy rainfall in recent 50 years in Anhui experienced five cycles in the 9 to 10 year time scale. There was a mutation around 1978, and the average rainfall from 1979 to 2008 is 583 mm higher than the average from 1961 to 1978.
    2019,47(5):780-785, DOI:
    [Abstract] (1279) [HTML] (0) [PDF 2.37 M] (10758)
    Abstract:
    With the rapid development of the Android system and Internet technology, the smart TV box hardware technology has become one of the most promising industries. The main focus of this paper is the application software designation of smart TV boxes. In order to enrich the means of mobile meteorological information service, smart TV box meteorological service software (weather box) has been widely developed by either using Android, Nginx, Web service or other technical solutions. In this paper, we detailed the newly designed hardware, i.e., system architecture and network topology. Then, we introduce software implementations. By using the newly proposed Load Balancing Strategy and Network Architecture Optimization, our production can dynamically be adaptive to those high concurrent users while maintaining the acceptable security level. Our product also follows the user experiences, which we previously received from our clients, to be convenient the operation process. The product can be potentially valuable as guidance for the relevance software designation towards smart TV boxes.
    Article Search
    Search by issue
    Select AllDeselectExport
    Display Method:
    2008,36(6):760-763, DOI:
    [Abstract] (5079) [HTML] (0) [PDF 464.40 K] (2560)
    Abstract:
    An analysis is made of the annual, seasonal, and monthly variation characteristics of sunshine duration in recent 50 years and its relationship with total cloudiness, trying to detect the variation of sunshine duration in Chengdu by the abrupt climate change theory. The results indicate that in recent 50 years, the sunshine duration decreased with a tendency of 69.41 hours per ten years; the interannual variation amplitude was obviously greater; and the difference between the sunshine durations in 1963 and in 1989 is up to 662.8 hours. There is obvious seasonal difference in sunshine duration, with bigger decreasing amplitude in summer and winter than those in spring and autumn and a tendency of -29.77 and -20.17, -9.91 and -9.56 hours per ten years, respectively. The decreasing tendency is obviously greater in August and less in April. The annual variation of sunshine duration is consistent with sunshine percentage. The sudden change occurred around 1978, with the annual sunshine duration decreased rapidly.
    2004,32(4):251, DOI:
    [Abstract] (5071) [HTML] (0) [PDF 423.81 K] (2916)
    Abstract:
    CINRAD/SA, China Next Generation Weather Radar,was produced by the Beijing METSATAR Radar Co., Ltd, based on the NEXRAD WSR-88D technology.Its software system was modified to provide the new RHI/PPI scan mode because NEXRAD WSR-88D provides only the volume scan mode. The design and realization of the RHI/PPI scan mode on the CINRAD/SA are described.
    2008,36(4):474-479, DOI:
    [Abstract] (4266) [HTML] (0) [PDF 650.10 K] (2141)
    Abstract:
    An observational experiment was conducted on the impact of air temperature and humidity variation on soil resistivity and earthing resistance with different structures by selecting three typical soil conditions to set three vari structure lightning protecting earthing bodies in Ningxia for one year. By means of comparative and regression analysis, the impacts of different soil conditions on soil resistivity at different temperatures and humidity in different seasons, and the variation characteristics and regularities of the lightning protecting earthing bodies with different structures are studied, and accordingly the optimal requirements for the layout and structure of lightning protecting earthing bodies are presented.
    2005,33(4):340-344, DOI:
    [Abstract] (3633) [HTML] (0) [PDF 146.22 K] (3930)
    Abstract:
    In order to develop and utilize reasonably climate resources and offer a scientific basis for the sub-area management of livestock production over grasslands, an analysis was made of the Inner Mongolia grassland climate characteristics and effects of climate on the growth of pasture grass, the distribution of domestic animal breeds and the soil environment. It is found that some isolines of climatic moisture are almost superposed with the boundaries of soil, which indicates that the formation of soil zones is closely related to climatic conditions, and climate and soil environment are main influence factors for pasture types and the ecosystem. Based on the climatic moisture, in combination with the distribution characteristics of soil over Inner Mongolia, a regionalization was carried out of grassland ecological types, which is not only rational, but also stable. It is pointed out that the climatic warming and the resulting changes in recent years improved, to some extent, the productivity of the grasslands, but not changed the ecotype in Inner Mongolia.
    2010,38(1):1-8, DOI:
    [Abstract] (3538) [HTML] (0) [PDF 988.69 K] (5425)
    Abstract:
    An introduction of the main reanalysis data of NCEP, ECMWF, JMA and the preliminary comparison among them are given from the following aspects: (1) assimilation systems, including the assimilation module and method; (2) the data used in the reanalysis; and (3) the methods of quality control and bias correction. The main assimilation methods of all reanalysis datasets include the 3D variational method, 4D variational method, and optimum interpolation. The dominating differences of these reanalysis datasets are data types and the resolution of modules. In addition, the advantages and deficiencies of these reanalysis datasets are given by empirical analysis. It is helpful for selecting the correct reanalysis dataset. The advances in reanalysis in China ars introduced simply and some problems on the improvement of the reanalysis in China are discussed.

WeChat

Mobile website

Most Read

Most Cited

Most Downloaded

You are thevisitors     Copyright:    
Organizer:中国气象局气象探测中心,中国气象科学研究院,北京市气象局,国家卫星气象中心,国家气象信息中心
     Address:北京市海淀区中关村南大街46号       E-mail:100081      Telephone :010-68407256      Fax:010-68407256
Supported by:Beijing E-Tiller Technology Development Co., Ltd.