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Data-Driven Load Forecasting Using Machine Learning and Meteorological Data
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作者 Aishah Alrashidi Ali Mustafa Qamar 《Computer Systems Science & Engineering》 SCIE EI 2023年第3期1973-1988,共16页
Electrical load forecasting is very crucial for electrical power systems’planning and operation.Both electrical buildings’load demand and meteorological datasets may contain hidden patterns that are required to be i... Electrical load forecasting is very crucial for electrical power systems’planning and operation.Both electrical buildings’load demand and meteorological datasets may contain hidden patterns that are required to be investigated and studied to show their potential impact on load forecasting.The meteorological data are analyzed in this study through different data mining techniques aiming to predict the electrical load demand of a factory located in Riyadh,Saudi Arabia.The factory load and meteorological data used in this study are recorded hourly between 2016 and 2017.These data are provided by King Abdullah City for Atomic and Renewable Energy and Saudi Electricity Company at a site located in Riyadh.After applying the data pre-processing techniques to prepare the data,different machine learning algorithms,namely Artificial Neural Network and Support Vector Regression(SVR),are applied and compared to predict the factory load.In addition,for the sake of selecting the optimal set of features,13 different combinations of features are investigated in this study.The outcomes of this study emphasize selecting the optimal set of features as more features may add complexity to the learning process.Finally,the SVR algorithm with six features provides the most accurate prediction values to predict the factory load. 展开更多
关键词 Electricity load forecasting meteorological data machine learning feature selection modeling real-world problems predictive analytics
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Spatial-temporal characteristics of drought detected from meteorological data with high resolution in Shaanxi Province, China 被引量:2
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作者 WANG Yudan KONG Yunfeng +1 位作者 CHEN Hao DING Yongjian 《Journal of Arid Land》 SCIE CSCD 2020年第4期561-579,共19页
The spatial pattern of meteorological factors cannot be accurately simulated by using observations from meteorological stations(OMS) that are distributed sparsely in complex terrain. It is expected that the spatial-te... The spatial pattern of meteorological factors cannot be accurately simulated by using observations from meteorological stations(OMS) that are distributed sparsely in complex terrain. It is expected that the spatial-temporal characteristics of drought in regions with complex terrain can be better represented by meteorological data with the high spatial-temporal resolution and accuracy. In this study, Standard Precipitation Evapotranspiration Index(SPEI) calculated with meteorological factors extracted from ITPCAS(China Meteorological Forcing Dataset produced by the Institute of Tibetan Plateau Research, Chinese Academy of Sciences) was applied to identify the spatial-temporal characteristics of drought in Shaanxi Province of China, during the period of 1979–2016. Drought areas detected by SPEI calculated with data from ITPCAS(SPEI-ITPCAS) on the seasonal scale were validated by historical drought records from the Chinese Meteorological Disaster Canon-Shaanxi, and compared with drought areas detected by SPEI calculated with data from OMS(SPEI-OMS). Drought intensity, trend and temporal ranges for mutations of SPEI-ITPCAS were analyzed by using the cumulative drought intensity(CDI) index and the Mann-Kendall test. The results indicated that drought areas detected from SPEI-ITPCAS were closer to the historical drought records than those detected from SPEI-OMS. Severe and exceptional drought events with SPEI-ITPCAS lower than –1.0 occurred most frequently in summer, followed by spring. There was a general drying trend in spring and summer in Shaanxi Province and a significant wetting trend in autumn and winter in northern Shaanxi Province. On seasonal and annual scales, the regional and temporal ranges for mutations of SPEI-ITPCAS were different and most mutations occurred before the year 1990 in most regions of Shaanxi Province. The results reflect the response of different regions of Shaanxi Province to climate change, which will help to manage regional water resources. 展开更多
关键词 SPEI drought areas meteorological data cumulative drought intensity drying trend wetting trend
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Towards Increasing Data Availability for Meteorological Services: Inter-Comparison of Meteorological Data from a Synoptic Weather Station and Two Automatic Weather Stations in Kenya 被引量:1
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作者 Richard Muita Paul Kucera +8 位作者 Stella Aura David Muchemi David Gikungu Samuel Mwangi Martin Steinson Paul Oloo Nicholas Maingi Ezekiel Muigai Mwaura Kamau 《American Journal of Climate Change》 2021年第3期300-316,共17页
Meteorological data is useful for varied applications and sectors ranging from weather and climate forecasting, landscape planning to disaster management among others. However, the availability of these data requires ... Meteorological data is useful for varied applications and sectors ranging from weather and climate forecasting, landscape planning to disaster management among others. However, the availability of these data requires a good network of manual meteorological stations and other support systems for its collection, recording, processing, archiving, communication and dissemination. In sub-Saharan Africa, such networks are limited due to low investment and capacity. To bridge this gap, the National Meteorological Services in Kenya and few others from African countries have moved to install a number of Automatic Weather Stations (AWSs) in the past decade including a few additions from private institutions and individuals. Although these AWSs have the potential to improve the existing observation network and the early warning systems in the region, the quality and capacity of the data collected from the stations are not well exploited. This is mainly due to low confidence, by data users, in electronically observed data. In this study, we set out to confirm that electronically observed data is of comparable quality to a human observer recorded data, and can thus be used to bridge data gaps at temporal and spatial scales. To assess this potential, we applied the simple Pearson correlation method and other statistical tests and approaches by conducting inter-comparison analysis of weather observations from the manual synoptic station and data from two Automatic Weather Stations (TAHMO and 3D-PAWS) co-located at KMD Headquarters to establish existing consistencies and variances in several weather parameters. Results show there is comparable consistency in most of the weather parameters between the three stations. Strong associations were noted between the TAHMO and manual station data for minimum (r = 0.65) and maximum temperatures (r = 0.86) and the maximum temperature between TAHMO and 3DPAWS (r = 0.56). Similar associations were indicated for surface pressure (r = 0.99) and RH (r > 0.6) with the weakest correlations occurring in wind direction and speed. The Shapiro test for normality assumption indicated that the distribution of several parameters compared between the 3 stations were normally distributed (p > 0.05). We conclude that these findings can be used as a basis for wider use of data sets from Automatic Weather Stations in Kenya and elsewhere. This can inform various applications in weather and climate related decisions. 展开更多
关键词 meteorological data Manual Weather Station Automatic Weather Station CORRELATION
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Wireless Backup System of Meteorological Data Transmission
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作者 Li Zhen Yu Shangyou 《Meteorological and Environmental Research》 CAS 2014年第5期1-2,5,共3页
By using wireless communication technology, when wired network of grassroots station is failure, wireless backup system of meteorological data transmission can automatically switch, and transmit the data at the statio... By using wireless communication technology, when wired network of grassroots station is failure, wireless backup system of meteorological data transmission can automatically switch, and transmit the data at the station with line fault to the destination by short message way. The system has simple operation and low operation cost, and transmission fault of real-time meteorological data due to line problem at the station can be effectively decreased. At present, the system has been tested successfully and put into business operation. 展开更多
关键词 Wireless backup system meteorological data Short message China
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Development of Management and Application System of Basic Meteorological Data
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作者 Hou Yiguang Zhao Jin +1 位作者 Li Bingfeng Wang Xiao 《Meteorological and Environmental Research》 CAS 2015年第7期17-22,共6页
Based on convenience and safety of historical data application, B/S mode is used instead of database management structure of C/S mode, and it can not only combine database and network, but also realize the safe use of... Based on convenience and safety of historical data application, B/S mode is used instead of database management structure of C/S mode, and it can not only combine database and network, but also realize the safe use of historical data online. High-level programming language is used to develop a online management and application system of historical meteorological data based on B/S mode. System data import function can import ground report file sequence of Xuzhou ( including five county-level stations) into the database, construct Oracle database of Xuzhou and the five stations since 1953, and establish data tables of time, day, ten-day, monthly, quarterly and annual historical data, weather information and so forth. Management software of database server is established to realize instruction-level management and scheduling of database and a balanced distribution of resources among users. At the same time, a Web-based management application interface is set up to meet users' needs to retrieve a variety of repositories, and it provides statistical query of time, day, ten-day, monthly, quarterly and annual historical data and climate data for each meteorological element, thereby meeting the needs of meteorological research and all sectors of society for statistical query of meteorological data. 展开更多
关键词 Basic meteorological data Management and application systems Web application China
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Research on Spatial Statistical Downscaling Method of Meteorological Data Applied to Photovoltaic Prediction
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作者 Yan Jin DingmeiWang +1 位作者 Ruiping Zhang Haiying Dong 《Energy Engineering》 EI 2022年第5期1923-1940,共18页
Aiming at the low spatial resolution of meteorological data output from a numerical model in photovoltaic power prediction,a geographically weighted statistical downscaling method considers the influence factors such ... Aiming at the low spatial resolution of meteorological data output from a numerical model in photovoltaic power prediction,a geographically weighted statistical downscaling method considers the influence factors such as normalized vegetation index(NDVI),digital elevation model(DEM),slope direction,longitude and latitude is proposed.This method is based on the correlation between meteorological data and NDVI,DEM,slope direction,latitude and longitude,and introduces DEM and local Moran index to improve the regression model,and obtains 100∗100 m high-resolution meteorological spatial distribution data.Finally,combining the measured data of the study area and the established EOF iterative downscaling method to verify and compare the downscaling results.The results show that the error between the downscaled meteorological data and the measured value is smaller,and the comprehensive downscaling accuracy of the geographically weighted regression method is higher,and the model fitting effect is better.Therefore,this method can effectively improve the influence of errors caused by lower resolution,and provide a more reliable meteorological basis for the prediction of photovoltaic power. 展开更多
关键词 Numerical model meteorological data resolving power
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Application of Meteorological Data Operation System(MDOS)in Meteorological Operation
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作者 Bingyu YANG Honghong HUANG +1 位作者 Qun ZHOU Kangning SHU 《Meteorological and Environmental Research》 CAS 2022年第1期31-34,共4页
Meteorological data operation system(MDOS)is a comprehensive business platform that integrates data transmission and monitoring,quality control,processing,storage and distribution,and data services.The operation and i... Meteorological data operation system(MDOS)is a comprehensive business platform that integrates data transmission and monitoring,quality control,processing,storage and distribution,and data services.The operation and implementation of MDOS has further improved the quality control system of meteorological data in Yunnan Province,adjusted the business layout of meteorological data,and made the availability ratio of meteorological data continue to increase.The availability ratio of meteorological data from national stations rose from 99.68% to 99.96%,and that of regional stations increased from 95.33% to 99.08% from 2016 to 2020.MDOS not only solves the problem of inconsistent data and quality control methods of various business platforms,but also provides guarantees for more refined and accurate weather forecasts and climate predictions. 展开更多
关键词 MDOS meteorological data Quality control
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Determination of Kolmogorov Entropy of Chaotic Attractor Included in One-Dimensional Time Series of Meteorological Data
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作者 严绍瑾 彭永清 王建中 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1991年第2期243-250,共8页
The 1970-1985 day to day averaged pressure dataset of Shanghai and the extension method in phase space are used to calculate the correlation dimension D and the second-order Renyi entropy K2 of the approximation of Ko... The 1970-1985 day to day averaged pressure dataset of Shanghai and the extension method in phase space are used to calculate the correlation dimension D and the second-order Renyi entropy K2 of the approximation of Kolmogorov's entropy, the fractional dimension D = 7.7-7.9 and the positive value K2 - 0.1 are obtained. This shows that the attractor for the short-term weather evolution in the monsoon region of China exhibits a chaotic motion. The estimate of K2 yields a predictable time scale of about ten days. This result is in agreement with that obtained earlier by the dynamic-statistical approach.The effects of the lag time i on the estimate of D and K2 are investigated. The results show that D and K2 are convergent with respect to i. The day to day averaged pressure series used in this paper are treated for the extensive phase space with T = 5, the coordinate components are independent of each other; therefore, the dynamical character quantities of the system are stable and reliable. 展开更多
关键词 Determination of Kolmogorov Entropy of Chaotic Attractor Included in One-Dimensional Time Series of meteorological data
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Effect of Meteorological Data Assimilation on Regional Air Quality Forecasts over the Korean Peninsula
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作者 Yunjae CHO Hyun Mee KIM +3 位作者 Eun-Gyeong YANG Yonghee LEE Jae-Bum LEE Soyoung HA 《Journal of Meteorological Research》 SCIE CSCD 2024年第2期262-284,共23页
The Weather Research and Forecasting model coupled with Chemistry(WRF-Chem),a type of online coupled chemistry-meteorology model(CCMM),considers the interaction between air quality and meteorology to improve air quali... The Weather Research and Forecasting model coupled with Chemistry(WRF-Chem),a type of online coupled chemistry-meteorology model(CCMM),considers the interaction between air quality and meteorology to improve air quality forecasting.Meteorological data assimilation(DA)can be used to reduce uncertainty in meteorological field,which is one factor causing prediction uncertainty in the CCMM.In this study,WRF-Chem and three-dimensional variational DA were used to examine the impact of meteorological DA on air quality and meteorological forecasts over the Korean Peninsula.The nesting model domains were configured over East Asia(outer domain)and the Korean Peninsula(inner domain).Three experiments were conducted by using different DA domains to determine the optimal model domain for the meteorological DA.When the meteorological DA was performed in the outer domain or both the outer and inner domains,the root-mean-square error(RMSE),bias of the predicted particulate matter(PM)concentrations,and the RMSE of predicted meteorological variables against the observations were smaller than those in the experiment where the meteorological DA was performed only in the inner domain.This indicates that the improvement of the synoptic meteorological fields by DA in the outer domain enhanced the meteorological initial and boundary conditions for the inner domain,subsequently improving air quality and meteorological predictions.Compared to the experiment without meteorological DA,the RMSE and bias of the meteorological and PM variables were smaller in the experiments with DA.The effect of meteorological DA on the improvement of PM predictions lasted for approximately 58-66 h,depending on the case.Therefore,the uncertainty reduction in the meteorological initial condition by the meteorological DA contributed to a reduction of the forecast errors of both meteorology and air quality. 展开更多
关键词 meteorological data assimilation regional air quality forecast particulate matter concentration optimal model domain forecast error WRF-Chem
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Assessment of Meteorological Threats to the Coordinated Search and Rescue of Unmanned/Manned Aircraft
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作者 Fei YAN Chuan LI +2 位作者 Xiaoyi FU Kefeng WU Yuying LI 《Meteorological and Environmental Research》 2024年第1期27-29,37,共4页
The architecture and working principle of coordinated search and rescue system of unmanned/manned aircraft,which is composed of manned/unmanned aircraft and manned aircraft,were first introduced,and they can cooperate... The architecture and working principle of coordinated search and rescue system of unmanned/manned aircraft,which is composed of manned/unmanned aircraft and manned aircraft,were first introduced,and they can cooperate with each other to complete a search and rescue task.Secondly,a threat assessment method based on meteorological data was proposed,and potential meteorological threats,such as storms and rainfall,can be predicted by collecting and analyzing meteorological data.Finally,an experiment was carried out to evaluate the performance of the proposed method in different scenarios.The experimental results show that the coordinated search and rescue system of unmanned/manned aircraft can be used to effectively assess meteorological threats and provide accurate search and rescue guidance. 展开更多
关键词 Unmanned/manned aircraft Coordinated search and rescue Assessment of meteorological threats meteorological data
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PNN based crop disease recognition with leaf image features and meteorological data 被引量:2
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作者 Shi Yun Wang Xianfeng +1 位作者 Zhang Shanwen Zhang Chuanlei 《International Journal of Agricultural and Biological Engineering》 SCIE EI CAS 2015年第4期60-68,共9页
An automatic crop disease recognition method was proposed in this paper,which combined the statistical features of leaf images and meteorological data.The images of infected crop leaves were taken under different envi... An automatic crop disease recognition method was proposed in this paper,which combined the statistical features of leaf images and meteorological data.The images of infected crop leaves were taken under different environments of the growth periods,temperature and humidity.The methods of image morphological operation,contour extraction and region growing algorithm were adopted for leaf image enhancement and spot image segmentation.From each image of infected crop leaf,the statistical features of color,texture and shape were extracted by image processing,and the optimal meteorological features with the highest accuracy rate were obtained and selected by the attribute reduction algorithm.The fusion feature vector of the image was formed by combining the statistical features and the meteorological features.Then the probabilistic neural networks(PNNs)classifier was adopted to evaluate the classification accuracy.The experimental results on three cucumber diseased leaf image datasets,i.e.,downy mildew,blight and anthracnose,showed that the crop diseases can be effectively recognized by the integrated application of leaf image processing technology,the disease meteorological data and PNNs classifier,and the recognition accuracy rate was higher than 90%,which indicated that the PNNs classifier trained on the disease feature coefficients extracted from the crop disease leaves and meteorological data could achieve higher classification accuracy. 展开更多
关键词 image processing crop disease recognition disease meteorological data MORPHOLOGY probabilistic neural networks(PNNs)
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SOME PROBLEMS AND TREATMENT IN THE REGRESSION ANALYSIS OF METEOROLOGICAL DATA
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作者 俞善贤 陈孝源 《Acta meteorologica Sinica》 SCIE 1990年第1期128-134,共7页
In this paper,some problems of regression analysis in the meteorological application are discussed and main reasons for statistical inference failures are analysed.We may find the failure problems with diagnos- tic me... In this paper,some problems of regression analysis in the meteorological application are discussed and main reasons for statistical inference failures are analysed.We may find the failure problems with diagnos- tic method and solve them by different treatment.It has been proved that the treatment make the accuracy and stability of forecasting improved greatly. 展开更多
关键词 SOME PROBLEMS AND TREATMENT IN THE REGRESSION ANALYSIS OF meteorological data THAN WANG
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Evaluation of Water Losses by Evaporation in the Nakanbe Basin
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作者 Bayala Alfred Kabre Sayouba +5 位作者 Yonli Hamma Fabien Chesneau Xavier Thierry Sikoudouin Maurice Ky Zeghmati Belkacem Kieno P. Florent Kam Sié 《Atmospheric and Climate Sciences》 2024年第1期29-41,共13页
A numerical approach to heat and mass transfer in a large water reservoir is presented. This water reservoir is likened to a parallelepiped reservoir whose vertical and lower walls are adiabatic and impermeable. The e... A numerical approach to heat and mass transfer in a large water reservoir is presented. This water reservoir is likened to a parallelepiped reservoir whose vertical and lower walls are adiabatic and impermeable. The equations that govern natural convection in water are solved by the finite volume method and Thomas’salgorithm. The adequacy between the velocity and pressure fields is ensured by the SIMPLE algorithm. We are going to evaluate the water losses by evaporation from three dams in the Nakanbé basin in Burkina Faso for a period of thirty years, that is to say from January 1, 1991, to March 15, 2020. The three dams have a rate of evaporation greater than 40% of the volume of water stored. Indeed the rate of evaporation in each dam increases with the water filling rate in the reservoir: we have observed the following results for each dam in the Nakanbé basin;for the date of 02/27/1988 to 03/13/2020., the Loumbila dam received a total volume of stored water of 22.02 Mm<sup>3</sup> and 10.57 Mm<sup>3</sup> as the total volume of water evaporated at the same date. At the Ouaga dam (2 + 3), it stored a water volume of 4.06 Mm<sup>3</sup> and evaporated 2.03 Mm<sup>3</sup> of its storage volume from 01/01/1988 to 05/07/2016. Finally, with regard to the Bagré dam, it stored 745.16 Mm<sup>3</sup> of water and 365.13 Mm<sup>3</sup> as the volume of water evaporated from 01/01/1993 to 03/31/2020. 展开更多
关键词 Numerical Study EVAPORATION meteorological data Natural Convection BASINS DAMS
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Numerical Modeling and Technico-Economic Analysis of a Hybrid Energy Production System for Self-Consumption: Case of Rural Area in the Comoros
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作者 Fahad Maoulida Mohamed Aboudou Kassim +2 位作者 Rabah Djedjig Ahmed Ihlal Mohammed El Ganaoui 《Journal of Power and Energy Engineering》 2024年第5期24-59,共36页
This study aims to provide electricity to a remote village in the Union of Comoros that has been affected by energy problems for over 40 years. The study uses a 50 kW diesel generator, a 10 kW wind turbine, 1500 kW ph... This study aims to provide electricity to a remote village in the Union of Comoros that has been affected by energy problems for over 40 years. The study uses a 50 kW diesel generator, a 10 kW wind turbine, 1500 kW photovoltaic solar panels, a converter, and storage batteries as the proposed sources. The main objective of this study is to conduct a detailed analysis and optimization of a hybrid diesel and renewable energy system to meet the electricity demand of a remote area village of 800 to 1500 inhabitants located in the north of Ngazidja Island in Comoros. The study uses the Hybrid Optimization Model for Electric Renewable (HOMER) Pro to conduct simulations and optimize the analysis using meteorological data from Comoros. The results show that hybrid combination is more profitable in terms of margin on economic cost with a less expensive investment. With a diesel cost of $1/L, an average wind speed of 5.09 m/s and a solar irradiation value of 6.14 kWh/m<sup>2</sup>/day, the system works well with a proportion of renewable energy production of 99.44% with an emission quantity of 1311.407 kg/year. 99.2% of the production comes from renewable sources with an estimated energy surplus of 2,125,344 kWh/year with the cost of electricity (COE) estimated at $0.18/kWh, presenting a cost-effective alternative compared to current market rates. These results present better optimization of the used hybrid energy system, satisfying energy demand and reducing the environmental impact. 展开更多
关键词 Hybrid System Rural Area Electrification COMOROS Techno-Economic Analysis PV-Wind-Diesel-Battery meteorological data HOMER Energy Pro
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Assessment of the methods for determining net radiation at different time-scales of meteorological variables
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作者 Ni An Sahar Hemmati Yu-Jun Cui 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2017年第2期239-246,共8页
When modeling the soil/atmosphere interaction,it is of paramount importance to determine the net radiation flux.There are two common calculation methods for this purpose.Method 1 relies on use of air temperature,while... When modeling the soil/atmosphere interaction,it is of paramount importance to determine the net radiation flux.There are two common calculation methods for this purpose.Method 1 relies on use of air temperature,while Method 2 relies on use of both air and soil temperatures.Nowadays,there has been no consensus on the application of these two methods.In this study,the half-hourly data of solar radiation recorded at an experimental embankment are used to calculate the net radiation and long-wave radiation at different time-scales(half-hourly,hourly,and daily) using the two methods.The results show that,compared with Method 2 which has been widely adopted in agronomical,geotechnical and geo-environmental applications.Method 1 is more feasible for its simplicity and accuracy at shorter time-scale.Moreover,in case of longer time-scale,daily for instance,less variations of net radiation and long-wave radiation are obtained,suggesting that no detailed soil temperature variations can be obtained.In other words,shorter time-scales are preferred in determining net radiation flux. 展开更多
关键词 Energy balance Net radiation Different time-scales meteorological data
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Improving Simulations of Vegetation Dynamics over the Tibetan Plateau:Role of Atmospheric Forcing Data and Spatial Resolution 被引量:1
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作者 Zhijie KANG Bo QIU +3 位作者 Zheng XIANG Ye LIU Zhiqiang LIN Weidong GUO 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2022年第7期1115-1132,I0018-I0022,共23页
The efficacy of vegetation dynamics simulations in offline land surface models(LSMs)largely depends on the quality and spatial resolution of meteorological forcing data.In this study,the Princeton Global Meteorologica... The efficacy of vegetation dynamics simulations in offline land surface models(LSMs)largely depends on the quality and spatial resolution of meteorological forcing data.In this study,the Princeton Global Meteorological Forcing Data(PMFD)and the high spatial resolution and upscaled China Meteorological Forcing Data(CMFD)were used to drive the Simplified Simple Biosphere model version 4/Top-down Representation of Interactive Foliage and Flora Including Dynamics(SSiB4/TRIFFID)and investigate how meteorological forcing datasets with different spatial resolutions affect simulations over the Tibetan Plateau(TP),a region with complex topography and sparse observations.By comparing the monthly Leaf Area Index(LAI)and Gross Primary Production(GPP)against observations,we found that SSiB4/TRIFFID driven by upscaled CMFD improved the performance in simulating the spatial distributions of LAI and GPP over the TP,reducing RMSEs by 24.3%and 20.5%,respectively.The multi-year averaged GPP decreased from 364.68 gC m^(-2)yr^(-1)to 241.21 gC m^(-2)yr^(-1)with the percentage bias dropping from 50.2%to-1.7%.When using the high spatial resolution CMFD,the RMSEs of the spatial distributions of LAI and GPP simulations were further reduced by 7.5%and 9.5%,respectively.This study highlights the importance of more realistic and high-resolution forcing data in simulating vegetation growth and carbon exchange between the atmosphere and biosphere over the TP. 展开更多
关键词 SSiB4 meteorological forcing data vegetation dynamics spatial resolution Tibetan Plateau
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Observed Impacts of Climate Variability on LULC in the Mesopotamia Region 被引量:1
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作者 Muntaha Alzubade Orkan Ozcan +1 位作者 Nebiye Musaoglu Murat Türke¸s 《Computers, Materials & Continua》 SCIE EI 2021年第5期2255-2269,共15页
Remote sensing analysis techniques have been investigated extensively,represented by a critical vision,and are used to advance our understanding of the impacts of climate change and variability on the environment.This... Remote sensing analysis techniques have been investigated extensively,represented by a critical vision,and are used to advance our understanding of the impacts of climate change and variability on the environment.This study aims to find a means of analysis that relies on remote sensing techniques to demonstrate the effects of observed climate variability on Land Use and Land Cover(LULC)of the Mesopotamia region,defined as a historical region located in the Middle East.This study employed the combined analysis of the Normalized Difference Vegetation Index(NDVI),Land Surface Temperature(LST),and two statistical analysis methods(Pearson Correlation Analysis,r;Coefficient of Determination,R^(2)),which were applied using the Moderate Resolution Imaging Spectroradiometer data and observed surface meteorological data from 2000 to 2018.The resulting NDVI images show five LULC classes with NDVI values varying between−0.3 and 0.9.Furthermore,changes in the classified LULC area were compared statistically to those in NDVI values,where a positive relationship was found.Also,when the LST values and temperature are more extreme,the NDVI values were found to be smaller,suggesting a decrease in the density of vegetation cover.A negative correlation was found through Pearson correlation analysis(r=∼−0.64),indicating a direct effect of increased temperatures on LULC.Indeed,this negative relationship between NDVI and LST was proven using R^(2) values,where a two-dimensional scatter plot analysis showed that R^(2) ranges from 0.54 to 0.9.Ultimately,the results obtained from this study reveal changes that may have many prominent effects in the field of LULC classification,accelerating the implications of climate change and variability factors. 展开更多
关键词 NDVI LST MODIS data meteorological data MESOPOTAMIA
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PV-Wind-Diesel System for Energy Supply on Remote Area Applied for Telecommunication Towers in Comoros 被引量:1
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作者 Fahad Maoulida Djedjig Rabah +1 位作者 Mohammed El Ganaoui Kassim Mohamed Aboudou 《Open Journal of Energy Efficiency》 2021年第2期50-72,共23页
The Comoros is an archipelago in the Indian Ocean located in the Mozambique Channel between the African continent and Madagascar. Geographically Comoros is composed of four islands: Grande Comores, Anjouan, Mohél... The Comoros is an archipelago in the Indian Ocean located in the Mozambique Channel between the African continent and Madagascar. Geographically Comoros is composed of four islands: Grande Comores, Anjouan, Mohéli and Mayotte (under French administration). Apart from Mayotte, the others three independent islands commonly known as the Union of the Comoros are suffering from energy stress since their independence year 1975 until nowadays. The energy supplied and distributed by the national electricity company, SONELEC produced by diesel engines, is not stable with so much load shedding all the time. This instability energy leads to a lack of a phone network in some telecommunications towers connected to grid. The majority of telecommunications towers are located in rural areas not connected to grid and running on diesel generators, which once again leads to a problem with the telecommunications network when diesel engines fail. The two competing companies which operate in the field of telecommunications in the Comoros, namely Comores Télécom, a national public company and Telma, the private one, are still unable to ensure the provision of the telecommunications network on a regular basis. This is why we propose in the present work, a sizing of hybrid system composed essentially of a diesel generator, a wind turbine and a photovoltaic solar system with storage in batteries for supplying telecommunications towers in order to permanently ensure the provision of the telecommunications network for the well-being of the population. Our future energy must be based on non-polluting energies with significant resources. Renewable energies are the best candidates but with intermittent production especially in rural areas not connected to the national electricity grid whose energy demand is more important to meet the needs of the population. The aim of this work is the sizing of a hybrid system composed of a diesel generator, a wind turbine and a photovoltaic solar system with storage in batteries for supplying telecommunications towers located in rural areas in the Comoros. In fact, to verify the performance of the hybrid system, a numerical study has been carried out with the HOMER 2.68 Beta software using meteorological data from the Comoros. The results obtained show that this hybrid combination is more profitable in the margin of economic cost and environmental assessments with a less expensive investment. These results also show a better optimization of Wind/PV/Battery of the hybrid system used, satisfying the demand and contributing to the preservation of the environment to fight against climate change with a low cost of energy. 展开更多
关键词 Hybrid System Renewable Energy HOMER meteorological data TELECOMMUNICATION TOWERS Rural Area
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Structure of Thunderstorm Gust Fronts with Topographic Effects
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作者 A. A. Bidokhti and T. Bani-Hashem Institute of Geophysics, Tehran University, P.O, Box 14155-6466, Tehran, LR. Iran 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2001年第6期1161-1174,共14页
Surface meteorological observations, associated with gust fronts produced by thunderstorm outflows over Tehran, an area surrounded by mountains, have been analyzed. Distinctive features are sudden drop in air temperat... Surface meteorological observations, associated with gust fronts produced by thunderstorm outflows over Tehran, an area surrounded by mountains, have been analyzed. Distinctive features are sudden drop in air temperature, up to 10°C, sharp increase in wind speed, up to 30 m s?1, with wind shift, to northwesterly, pressure jump, up to 4 hPa, humidity increase, up to 40%, and rain after some 20 min. Gust fronts which often occur in spring time, have a typical thickness of about 1.5 km and produce vertical wind shear of the order of 10?2s?1. Although these features seem to be common for most of the events, their intensities differ from one event to another, indicating that the gust fronts may occur in different sizes and shapes. Apart from a dominant effect on the formation of the original thunderstorms, topography appears to break up the frontal structure of the gust fronts. The internal Rossby radius of deformation for these flows is small enough (~ 100 km) for rotational effects to be minor. A laboratory model of the gust front (gravity current) also shows that it initially has a distinctive head with a turbulent wake, and can be broken up by topography. It is shown that when the environment is stratified, turbulence due to lobes and clefts instabilities near the nose of the current is suppressed. When the ground is rough, these instabilities are highly amplified and the internal Froude number of the flow is reduced. The bottom slope in the presence of rough topography leads to the break up of the current head and produces a broad and highly non-uniform head, recognized in the density signals. Key words Frontal structure - Gravity current - Meteorological data - Outflows 展开更多
关键词 Frontal structure Gravity current meteorological data OUTFLOWS
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Modeling of Trophospheric Ozone Concentrations Using Genetically Trained Multi-Level Cellular Neural Networks
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作者 H.Kurtulus OZCAN Erdem BILGILI +2 位作者 Ulku SAHIN O.Nuri UCAN Cuma BAYAT 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2007年第5期907-914,共8页
Tropospheric ozone concentrations, which are an important air pollutant, are modeled by the use of an artificial intelligence structure. Data obtained from air pollution measurement stations in the city of Istanbul ar... Tropospheric ozone concentrations, which are an important air pollutant, are modeled by the use of an artificial intelligence structure. Data obtained from air pollution measurement stations in the city of Istanbul are utilized in constituting the model. A supervised algorithm for the evaluation of ozone concentration using a genetically trained multi-level cellular neural network (ML-CNN) is introduced, developed, and applied to real data. A genetic algorithm is used in the optimization of CNN templates. The model results and the actual measurement results are compared and statistically evaluated. It is observed that seasonal changes in ozone concentrations are reflected effectively by the concentrations estimated by the multilevel-CNN model structure, with a correlation value of 0.57 ascertained between actual and model results. It is shown that the multilevel-CNN modeling technique is as satisfactory as other modeling techniques in associating the data in a complex medium in air pollution applications. 展开更多
关键词 genetic algorithm cellular neural networks (CNN) OZONE meteorological data
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