A joint statistical model of wind speed and wind shear is critical for height-dependent wind resource characteristic analysis.However,given the different atmospheric conditions that may be involved,the statistical dis...A joint statistical model of wind speed and wind shear is critical for height-dependent wind resource characteristic analysis.However,given the different atmospheric conditions that may be involved,the statistical distribution of the two variables may show multimodal characteristics.In this work,a finite mixture bivariate statistical model was designed to describe the statistical properties,which is composed of several components,each with a Weibull distribution and a normal distribution for wind speed and wind shear,respectively,with a Gaussian copula to describe the dependency structure between the two variables.To confirm the developed model,reanalysis data from six positions in the coastal sea areas of China were used.Our results disclosed that the developed joint statistical model can accurately capture the different multimodal structures presented in all the bivariate samples under mixed atmospheric conditions,giving acceptable predictions of the joint probability distributions.Proper consideration of wind shear coefficient variation is crucial in estimating height-dependent wind resource characteristics.Importantly,unlike traditional methods that are limited to specific hub heights,the model developed here can estimate wind energy potential across different hub heights,enhancing the economic viability assessment of wind power projects.展开更多
Methane （CH4） emissions estimated with the Intergovernmental Panel on Climate Change （IPCC） inventory method at the city and regional scale are subject to large uncertainties.In this study,we determined the CH4：C...Methane （CH4） emissions estimated with the Intergovernmental Panel on Climate Change （IPCC） inventory method at the city and regional scale are subject to large uncertainties.In this study,we determined the CH4：CO2 emissions ratio for both Nanjing and the Yangtze River Delta （YRD）,using the atmospheric CH4 and CO2 concentrations measured at a suburban site in Nanjing in the winter.The atmospheric estimate of the CH4：CO2 emissions ratio was in reasonable agreement with that calculated using the IPCC method for the YRD （within 20％）,but was 200％ greater for the municipality of Nanjing.The most likely reason for the discrepancy is that emissions from unmanaged landfills are omitted from the official statistics on garbage production.展开更多
A simple method for estimating the contributions of mineral dust to PM2.5, PM10, or TSP is presented. The method is based on the assumption of external mixing of two types of particles with different PM2.5/PM10 ratios...A simple method for estimating the contributions of mineral dust to PM2.5, PM10, or TSP is presented. The method is based on the assumption of external mixing of two types of particles with different PM2.5/PM10 ratios, The method was applied to local and transported dust events observed in Tsukuba, Japan, and was compared with collocated polarization lidar measurements. The method was then applied to three dust events that occurred in Oki, Rishiri, and Ochiishi,Japan, in 2012. The results showed that the method was useful for detecting mineral dust and for qualitatively describing the mixing of dust with anthropogenic aerosols.展开更多
基金supported by the Key R&D Program of Shandong Province,China(No.2021ZLGX04)the National Natural Science Foundation of China(No.52171284)。
文摘A joint statistical model of wind speed and wind shear is critical for height-dependent wind resource characteristic analysis.However,given the different atmospheric conditions that may be involved,the statistical distribution of the two variables may show multimodal characteristics.In this work,a finite mixture bivariate statistical model was designed to describe the statistical properties,which is composed of several components,each with a Weibull distribution and a normal distribution for wind speed and wind shear,respectively,with a Gaussian copula to describe the dependency structure between the two variables.To confirm the developed model,reanalysis data from six positions in the coastal sea areas of China were used.Our results disclosed that the developed joint statistical model can accurately capture the different multimodal structures presented in all the bivariate samples under mixed atmospheric conditions,giving acceptable predictions of the joint probability distributions.Proper consideration of wind shear coefficient variation is crucial in estimating height-dependent wind resource characteristics.Importantly,unlike traditional methods that are limited to specific hub heights,the model developed here can estimate wind energy potential across different hub heights,enhancing the economic viability assessment of wind power projects.
基金supported by the Ministry of Education of China (Grant PCSIRT)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)+2 种基金the National Natural Science Foundation of China (Grant No.31100359)the Natural Science Foundation of Jiangsu Province (Grant No.BK2011830)the Ningbo Planning Project of Science and Technology (Grant No.2012C50044)
文摘Methane （CH4） emissions estimated with the Intergovernmental Panel on Climate Change （IPCC） inventory method at the city and regional scale are subject to large uncertainties.In this study,we determined the CH4：CO2 emissions ratio for both Nanjing and the Yangtze River Delta （YRD）,using the atmospheric CH4 and CO2 concentrations measured at a suburban site in Nanjing in the winter.The atmospheric estimate of the CH4：CO2 emissions ratio was in reasonable agreement with that calculated using the IPCC method for the YRD （within 20％）,but was 200％ greater for the municipality of Nanjing.The most likely reason for the discrepancy is that emissions from unmanaged landfills are omitted from the official statistics on garbage production.
文摘A simple method for estimating the contributions of mineral dust to PM2.5, PM10, or TSP is presented. The method is based on the assumption of external mixing of two types of particles with different PM2.5/PM10 ratios, The method was applied to local and transported dust events observed in Tsukuba, Japan, and was compared with collocated polarization lidar measurements. The method was then applied to three dust events that occurred in Oki, Rishiri, and Ochiishi,Japan, in 2012. The results showed that the method was useful for detecting mineral dust and for qualitatively describing the mixing of dust with anthropogenic aerosols.
