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The GNSS PWV retrieval using non-observation meteorological parameters based on ERA5 and its relation with precipitation
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作者 Weifeng Yang Zhiping Chen +2 位作者 Kaiyun Lv Pengfei Xia Tieding Lu 《Geodesy and Geodynamics》 EI CSCD 2024年第3期302-313,共12页
The pressure and temperature significantly influence precipitable water vapor(PWV) retrieval. Global Navigation Satellite System(GNSS) PWV retrieval is limited because the GNSS stations lack meteorological sensors. Fi... The pressure and temperature significantly influence precipitable water vapor(PWV) retrieval. Global Navigation Satellite System(GNSS) PWV retrieval is limited because the GNSS stations lack meteorological sensors. First, this article evaluated the accuracy of pressure and temperature in 68 radiosonde stations in China based on ERA5 Reanalysis data from 2015 to 2019 and compared them with GPT3model. Then, the accuracy of pressure and temperature calculated by ERA5 were estimated in 5 representative IGS stations in China. And the PWV calculated by these meteorological parameters from ERA5(ERA5-PWV) were analyzed. Finally, the relation between ERA5-PWV and precipitation was deeply explored using wavelet coherence analysis in IGS stations. These results indicate that the accuracy of pressure and temperature of ERA5 is better than the GPT3 model. In radiosonde stations, the mean BIAS and MAE of pressure and temperature in ERA5 are-0.41/1.15 hpa and-0.97/2.12 K. And the mean RMSEs are 1.35 hpa and 2.87 K, which improve 74.77% and 40.58% compared with GPT3 model. The errors of pressure and temperature of ERA5 are smaller than the GPT3 model in bjfs, hksl and wuh2, and the accuracy of ERA5-PWV is improved by 18.77% compared with the GPT3 model. In addition, there is a significant positive correlation between ERA5-PWV and precipitation. And precipitation is always associated with the sharp rise of ERA5-PWV, which provides important references for rainfall prediction. 展开更多
关键词 ERA5 GNSS precipitable water vapor precipitation Wavelet coherence analysis
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Future Changes and Uncertainties in Temperature and Precipitation over China Based on CMIP5 Models 被引量:23
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作者 TIAN Di GUO Yan DONG Wenjie 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2015年第4期487-496,共10页
Climate changes in future 21 st century China and their uncertainties are evaluated based on 22 climate models from the Coupled Model Intercomparison Project Phase 5(CMIP5). By 2081–2100, the annual mean surface ai... Climate changes in future 21 st century China and their uncertainties are evaluated based on 22 climate models from the Coupled Model Intercomparison Project Phase 5(CMIP5). By 2081–2100, the annual mean surface air temperature(SAT) is predicted to increase by 1.3℃± 0.7℃, 2.6℃± 0.8℃ and 5.2℃± 1.2℃ under the Representative Concentration Pathway(RCP) scenarios RCP2.6, RCP4.5 and RCP8.5, relative to 1986–2005, respectively. The future change in SAT averaged over China increases the most in autumn/winter and the least in spring, while the uncertainty shows little seasonal variation.Spatially, the annual and seasonal mean SAT both show a homogeneous warming pattern across China, with a warming rate increasing from southeastern China to the Tibetan Plateau and northern China, invariant with time and emissions scenario.The associated uncertainty in SAT decreases from northern to southern China. Meanwhile, by 2081–2100, the annual mean precipitation increases by 5% ± 5%, 8% ± 6% and 12% ± 8% under RCP2.6, RCP4.5 and RCP8.5, respectively. The national average precipitation anomaly percentage, largest in spring and smallest in winter, and its uncertainty, largest in winter and smallest in autumn, show visible seasonal variations. Although at a low confidence level, a homogeneous wetting pattern is projected across China on the annual mean scale, with a larger increasing percentage in northern China and a weak drying in southern China in the early 21 st century. The associated uncertainty is also generally larger in northern China and smaller in southwestern China. In addition, both SAT and precipitation usually show larger seasonal variability on the sub-regional scale compared with the national average. 展开更多
关键词 CMIP5 China surface air temperature precipitation PROJECTION UNCERTAINTY
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Evaluation of IMERG, TMPA, ERA5, and CPC precipitation products over China's Mainland: Spatiotemporal patterns and extremes 被引量:5
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作者 Shan-hu Jiang Lin-yong Wei +3 位作者 Li-liang Ren Lin-qi Zhang Meng-hao Wang Hao Cui 《Water Science and Engineering》 EI CAS CSCD 2023年第1期45-56,共12页
A comprehensive assessment of representative satellite-retrieved(Integrated Multi-satellite Retrievals for Global Precipitation Measurement(IMERG)and Tropical Rainfall Measuring Mission Multi-satellite Precipitation A... A comprehensive assessment of representative satellite-retrieved(Integrated Multi-satellite Retrievals for Global Precipitation Measurement(IMERG)and Tropical Rainfall Measuring Mission Multi-satellite Precipitation Analysis(TMPA)),reanalysis-based(fifth generation of atmospheric reanalysis by the European Centre for Medium Range Weather Forecasts(ERA5)),and gauge-estimated(Climate Prediction Center(CPC))precipitation products was conducted using the data from 807 meteorological stations across China's Mainland from 2001 to 2017.Error statistical metrics,precipitation distribution functions,and extreme precipitation indices were used to evaluate the quality of the four precipitation products in terms of multi-timescale accuracy and extreme precipitation estimation.When the timescale increased from daily to seasonal scales,the accuracy of the four precipitation products first increased and then decreased,and all products performed best on the monthly timescale.Their accuracy ranking in descending order was CPC,IMERG,TMPA,and ERA5 on the daily timescale and IMERG,CPC,TMPA,and ERA5 on the monthly and seasonal timescales.IMERG was generally superior to its predecessor TMPA on the three timescales.ERA5 exhibited large statistical errors.CPC provided stable estimated values.For extreme precipitation estimation,the quality of IMERG was relatively consistent with that of TMPA in terms of precipitation distribution and extreme metrics,and IMERG exhibited a significant advantage in estimating moderate and heavy precipitation.In contrast,ERA5 and CPC exhibited poor performance with large systematic underestimation biases.The findings of this study provide insight into the performance of the latest IMERG product compared with the widely used TMPA,ERA5,and CPC datasets,and points to possible directions for improvement of multi-source precipitation data fusion algorithms in order to better serve hydrological applications. 展开更多
关键词 IMERG TMPA ERA5 CPC Extreme precipitation
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Future Precipitation Extremes in China under Climate Change and Their Physical Quantification Based on a Regional Climate Model and CMIP5 Model Simulations 被引量:8
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作者 Peihua QIN Zhenghui XIE +2 位作者 Jing ZOU Shuang LIU Si CHEN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2021年第3期460-479,共20页
The atmospheric water holding capacity will increase with temperature according to Clausius-Clapeyron scaling and affects precipitation.The rates of change in future precipitation extremes are quantified with changes ... The atmospheric water holding capacity will increase with temperature according to Clausius-Clapeyron scaling and affects precipitation.The rates of change in future precipitation extremes are quantified with changes in surface air temperature.Precipitation extremes in China are determined for the 21st century in six simulations using a regional climate model,RegCM4,and 17 global climate models that participated in CMIP5.First,we assess the performance of the CMIP5 models and RCM runs in their simulation of extreme precipitation for the current period(RF:1982-2001).The CMIP5 models and RCM results can capture the spatial variations of precipitation extremes,as well as those based on observations:OBS and XPP.Precipitation extremes over four subregions in China are predicted to increase in the mid-future(MF:2039-58)and far-future(FF:2079-98)relative to those for the RF period based on both the CMIP5 ensemble mean and RCM ensemble mean.The secular trends in the extremes of the CMIP5 models are predicted to increase from 2008 to 2058,and the RCM results show higher interannual variability relative to that of the CMIP5 models.Then,we quantify the increasing rates of change in precipitation extremes in the MF and FF periods in the subregions of China with the changes in surface air temperature.Finally,based on the water vapor equation,changes in precipitation extremes in China for the MF and FF periods are found to correlate positively with changes in the atmospheric vertical wind multiplied by changes in surface specific humidity(significant at the p<0.1 level). 展开更多
关键词 precipitation extremes regional climate model CMIP5 models
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Assessment of model performance of precipitation extremes over the mid-high latitude areas of Northern Hemisphere:from CMIP5 to CMIP6 被引量:11
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作者 LIN Wenqing CHEN Huopo 《Atmospheric and Oceanic Science Letters》 CSCD 2020年第6期598-603,共6页
This study explores the model performance of the Coupled Model Intercomparison Project Phase 6(CMIP6)in simulating precipitation extremes over the mid–high latitudes of Asia,as compared with predecessor models in the... This study explores the model performance of the Coupled Model Intercomparison Project Phase 6(CMIP6)in simulating precipitation extremes over the mid–high latitudes of Asia,as compared with predecessor models in the previous phase,CMIP5.Results show that the multimodel ensemble median generally outperforms the individual models in simulating the climate means of precipitation extremes.The CMIP6 models possess a relatively higher capability in this respect than the CMIP5 models.However,discrepancies also exist between models and observation,insofar as most of the simulated indices are positively biased to varying degrees.With respect to the temporal performance of indices,the majority are overestimated at most time points,along with large uncertainty.Therefore,the capacity to simulate the interannual variability needs to be further improved.Furthermore,pairwise and multimodel ensemble comparisons were performed for 12 models to evaluate the performance of individual models,revealing that most of the new-version models are better than their predecessors,albeit with some variance in the metrics amongst models and indices. 展开更多
关键词 precipitation extremes CMIP5 CMIP6 the mid-high latitudes of Asia
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Intensified East Asian summer monsoon and associated precipitation mode shift under the 1.5 ℃ global warming target 被引量:7
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作者 WANG Tao MIAO Jia-Peng +1 位作者 SUN Jian-Qi FU Yuan-Hai 《Advances in Climate Change Research》 SCIE CSCD 2018年第2期102-111,共10页
In this study, the East Asian summer climate changes under the 1.5 ℃ global warming (1.5 GW) target in 30 simulations derived from 15 coupled models within the Coupled Model Intercomparison Program phase 5 (CMIP5... In this study, the East Asian summer climate changes under the 1.5 ℃ global warming (1.5 GW) target in 30 simulations derived from 15 coupled models within the Coupled Model Intercomparison Program phase 5 (CMIP5) are examined. Compared with the current summer climate (1975-2005), both surface air temperature and precipitation increase significantly over the East Asian continent during the 1.5 GW period (average period 2021-2051). In northeastern China this is particularly pronounced with regional averaged precipitation increases of more than 7.2%, which is greater than that for the whole East Asian continent (approximately 4.2%). Due to stronger enhancement of precipitation north of 40°N, the leading empirical orthogonal function (EOF) mode of summer precipitation over the East Asian continent changes from tripolar-like mode to dipole mode. As there is stronger surface warming over the East Asian continent than that over surrounding ocean, the land-sea thermal contrast is enhanced during the 1.5 GW period. As a result, the monsoon circulation in the lower troposphere is significantly strengthened, which causes the increased summer precipitation over the East Asian continent. In addition, larger interannual variabilities of East Asian summer monsoon circulation and associated precipitation are also suggested for the 1.5 GW period. 展开更多
关键词 East Asian summer monsoon precipitation 1.5 global warming target CMIP5
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ECHAM5-Simulated Impacts of Two Types of El Nio on the Winter Precipitation Anomalies in South China 被引量:8
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作者 SU Jing-Zhi ZHANG Ren-He ZHU Cong-Wen 《Atmospheric and Oceanic Science Letters》 CSCD 2013年第5期360-364,共5页
The authors used an atmospheric general circulation model (AGCM) of European Centre Hamburg Model (ECHAM5.4) and investigated the possible impacts of eastern Pacific (EP) and central Pacific (CP) El Ni(n)o o... The authors used an atmospheric general circulation model (AGCM) of European Centre Hamburg Model (ECHAM5.4) and investigated the possible impacts of eastern Pacific (EP) and central Pacific (CP) El Ni(n)o on the winter precipitation anomalies in South China.A composite analysis suggested much more rainfall during the mature phase of EP El Ni(n)o than in the case of CP El Ni(n)o,and their corresponding observed wet centers to be located in the southeast coast and the region to the south of the Yangtze River,respectively.Results obtained on the basis of model-sensitive run imply that the modelsimulated rainfall anomalies agree well with the observation,and the magnitude of simulated rainfall anomalies were found to be reduced when the amplitude of sea surface temperature anomaly (SSTA) forcing of EP and CP El Ni(n)o was cut down.These results imply that the rainfall anomaly in South China is very sensitive not only to the type of El Ni(n)o but also to its intensity. 展开更多
关键词 eastern/central Pacific El Ni(n)o precipitation ECHAM5 South China
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ENSO combination mode and its influence on seasonal precipitation over southern China simulated by ECHAM5/MPI-OM 被引量:2
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作者 YI Shengjie ZHENG Fei LUO Hao 《Atmospheric and Oceanic Science Letters》 CSCD 2019年第3期184-191,共8页
Recent studies show that a combination mode (C-mode) represents the seasonally modulated dynamics of ENSO, which plays an important role in maintaining the western North Pacific anomalous anticyclone. This C-mode coul... Recent studies show that a combination mode (C-mode) represents the seasonally modulated dynamics of ENSO, which plays an important role in maintaining the western North Pacific anomalous anticyclone. This C-mode could obviously influence the East Asian climate, especially since the contribution of ENSO to southern China's precipitation has weakened since the late 1990s. This paper evaluates whether the C-mode and its influences on precipitation over southern China can be realistically described by the climate model ECHAM5/MPI-OM. The authors find that the model is able to reproduce the spatial and temporal variability of the C-mode and the asymmetric responses of air-sea variations in the tropical Pacific. The model also reveals the observed significant effects of the C-mode on the wintertime and springtime rainfall over southern China during El Nino events. The findings have implications for ECHAM5/MPI-OM being a valuable tool for simulating and predicting the C-mode-related seasonal precipitation over southern China. 展开更多
关键词 C-mode precipitation Southern China ECHAM5/MPI-OM
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How Large Precipitation Changes over Global Monsoon Regions by CMIP5 Models? 被引量:2
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作者 CHEN Huo-Po SUN Jian-Qi 《Atmospheric and Oceanic Science Letters》 CSCD 2013年第5期306-311,共6页
Future changes in precipitation over global monsoon domains and their adjacent dry regions are investigated using present-day climate simulations(1986–2005)and future climate simulations under the Representative Conc... Future changes in precipitation over global monsoon domains and their adjacent dry regions are investigated using present-day climate simulations(1986–2005)and future climate simulations under the Representative Concentration Pathways(RCP4.5)scenario by the Coupled Model Intercomparison Project Phase 5(CMIP5)models.In the present-day climate simulations,high reproducibility of the extents of global monsoon domains and dry regions is observed from the multi-model ensemble(MME)result;the associated local summer precipitation variation and its interannual variability are also successfully reproduced.In the future,the global monsoon domains are projected to be expanded,while the dry regions are expected to initially increase and then decrease.The summer precipitation and its variability show significant increases over most global monsoon domains and obvious decreases over their adjacent dry regions.These results indicate that currently wet regions will become wetter and dry areas will be dryer under global warming conditions.Further analysis indicates that changes in summer precipitation over global monsoon and dry regions can be interpreted as moisture convergence changes associated with changes in horizontal moisture transport. 展开更多
关键词 CMIP5 global monsoon summer precipitation moisture convergence PROJECTION
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Intercomparison of CRA-Interim Precipitation Products with ERA5 and JRA-55 被引量:4
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作者 YE Meng-shu YAO Xiu-ping +2 位作者 ZHANG Tao XU Xiao-feng WANG Shi-gong 《Journal of Tropical Meteorology》 SCIE 2021年第2期136-147,共12页
Based on the hourly observational data during 2007-2016 from surface meteorological stations in China,this paper compares the influence of 3-hourly precipitation data,mainly from the Chinese Reanalysis-Interim(CRA-Int... Based on the hourly observational data during 2007-2016 from surface meteorological stations in China,this paper compares the influence of 3-hourly precipitation data,mainly from the Chinese Reanalysis-Interim(CRA-Interim),ECMWF Reanalysis 5(ERA5)and Japanese Reanalysis-55(JRA-55),on the simulation of the spatial and temporal distribution of regional precipitation in China and the bias distribution of the simulation.The results show that:(1)The three sets of reanalysis datasets can all reflect the basic spatial distribution characteristics of annual average precipitation in China.The simulation of topographic forced precipitation in complex terrain by using CRA-interim is more detailed,while CRA-interim has larger negative bias in central and East China,and larger positive bias in southwest China.(2)In terms of seasonal precipitation,the three sets of reanalysis datasets overestimate the precipitation in the heavy rainfall zone in spring and summer,especially in southwest China.According to CRA-interim,location of the rain belt in the First Rainy Season in South China is west by south,and the summer precipitation has positive bias in southwest and South China.(3)All of the reanalysis datasets can basically reflect the distribution difference of inter-annual variation of drought and flood,but overall the CRA-Interim generally shows negative bias,while the ERA5 and JRA-55 exhibit positive bias.(4)For the diurnal variation of precipitation in summer,all the reanalysis datasets perform better in simulating the daytime precipitation than in the night,and the bias of CRA-interim is less in the Southeast and Northeast than elsewhere.(5)The ERA5 generally performs the best on the evaluation of quantitative precipitation forecast,the JRA-55 is the next,followed by the CRA-Interim.The CRA-Interim has higher missing rate and lower threat score for heavy rains;however,at the level of downpour,the CRA-Interim performs slightly better. 展开更多
关键词 reanalysis datasets temporal and spatial distributions of precipitation CRA ERA5 JRA-55
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Assessing the Applicability of Multi-Source Precipitation Products over the Chinese Mainland and Its Seven Regions
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作者 TIAN Wei WU Yun-long +2 位作者 LIN Chen ZHANG Jing-guo LIM KAM SIAN Kenny Thiam Choy 《Journal of Tropical Meteorology》 SCIE 2024年第3期275-288,共14页
Satellite-based and reanalysis precipitation products provide valuable information for various applications.However,their performance varies widely across regions due to different data sources and production processes... Satellite-based and reanalysis precipitation products provide valuable information for various applications.However,their performance varies widely across regions due to different data sources and production processes.This paper evaluated the daily performance of four precipitation products(MSWEP,ERA5,PERSIANN,and TRMM)for seven regions of the Chinese mainland,using observations from 2462 ground stations across the country as a benchmark.We used four statistical and four classification indicators to describe their spatial and temporal accuracy,and capability to detect precipitation events while analyzing their applicability.The results show that according to the precipitation char-acteristics and accuracy of different types of precipitation products over the Chinese mainland,MSWEP was the most suitable product over the Chinese mainland,having the lowest root mean square error and mean absolute error,along with the highest coefficient of determination.It was followed by TRMM and ERA5,whereas PERSIANN lagged behind in terms of performance.In terms of different regions,MSWEP still performed well,especially in North China and East China.The accuracy of the four precipitation products was relatively low in the summer months,and they all overestimated in the northwest region.In other months,MSWEP and TRMM were better than PERSIANN and ERA5.The four precipitation products had good detection performance over the Chinese mainland,with probability of detection above 0.5.However,with the increase of precipitation threshold,the detection capability of the four products decreased,and MSWEP and ERA5 had good detection capability for moderate rain.TRMM’s detection capability for heavy rain and rainstorms was better than that of the other three products,and PERSIANN’s detection capability for moderate rain,heavy rain and rainstorms was relatively poor,with a large deviation. 展开更多
关键词 precipitation product MSWEP TRMM ERA5 PERSIANN
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Synthesis and luminescence properties of nanocrystalline Gd_3Ga_5O_(12):Eu^(3+) by a homogeneous precipitation method 被引量:3
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作者 Li Yanhong Lu Haiyan +2 位作者 Zhang Yongming Ma Jing Song Guoyi 《Rare Metals》 SCIE EI CAS CSCD 2012年第6期599-603,共5页
Nanocrystalline Gd3Ga5O12:Eu3+ with cubic phase was prepared by a urea homogeneous precipitation method. X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), Fourier transform infrared spectrosc... Nanocrystalline Gd3Ga5O12:Eu3+ with cubic phase was prepared by a urea homogeneous precipitation method. X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), thermo-gravimetric and differential thermal analysis (TG-DTA) and photoluminescence spectra were used to characterize the samples. The effects of the initial solution pH value and urea content on the structure of the sample were studied. The XRD results show that pure phase Gd3Ga5O12 can be obtained at pH =6 and pH =8 of the initial solution. The average crystallite size can be calculated as in the range of 24~33 nm. The average crystallite size decreases with increasing molar ratio of urea to metal ion. The results of excitation spectra and emission spectra show that the emission peaks are ascribed to 5D0→7FJ transitions of Eu3+, and the magnetic dipole transition originated from 5D0 →7F1 of Eu3+ is the strongest; the broad excitation bands belong to change transfer band of Eu?O and the host absorption of Gd3Ga5O12. An efficient energy transfer occurs from Gd3+ to Eu3+. 展开更多
关键词 Gd3Ga5O12:Eu3+ nanocrystal urea homogeneous precipitation method LUMINESCENCE
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Robustness of Precipitation Projections in China:Comparison between CMIP5 and CMIP3 Models 被引量:1
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作者 CHEN Huo-Po SUN Jian-Qi 《Atmospheric and Oceanic Science Letters》 CSCD 2014年第1期67-73,共7页
Three sources of uncertainty in model projections of precipitation change in China for the 21st century were separated and quantified: internal variability,inter-model variability,and scenario uncertainty.Simulations ... Three sources of uncertainty in model projections of precipitation change in China for the 21st century were separated and quantified: internal variability,inter-model variability,and scenario uncertainty.Simulations from models involved in the third phase and the fifth phase of the Coupled Model Intercomparison Project(CMIP3 and CMIP5) were compared to identify improvements in the robustness of projections from the latest generation of models.No significant differences were found between CMIP3 and CMIP5 in terms of future precipitation projections over China,with the two datasets both showing future increases.The uncertainty can be attributed firstly to internal variability,and then to both inter-model and internal variability.Quantification analysis revealed that the uncertainty in CMIP5 models has increased by about 10%–60% with respect to CMIP3,despite significant improvements in the latest generation of models.The increase is mainly due to the increase of internal variability in the initial decades,and then mainly due to the increase of inter-model variability thereafter,especially by the end of this century.The change in scenario uncertainty shows no major role,but makes a negative contribution to begin with,and then an increase later. 展开更多
关键词 precipitation PROJECTION UNCERTAINTY CMIP3 CMIP5
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Residual stress and precipitation of Mg-5Zn-3.5Sn-1Mn-0.5Ca-0.5Cu alloy with different quenching rates 被引量:2
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作者 Cong Wang Tianjiao Luo +2 位作者 Yunteng Liu Qiuyan Huang Yuansheng Yang 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2021年第2期604-612,共9页
The effect of the quenching rate after solution treatment on the residual stress and precipitation behavior of a high strength Mg-5 Zn-3.5 Sn-1 Mn-0.5 Ca-0.5 Cu plate is studied.The simulation results show decreasing ... The effect of the quenching rate after solution treatment on the residual stress and precipitation behavior of a high strength Mg-5 Zn-3.5 Sn-1 Mn-0.5 Ca-0.5 Cu plate is studied.The simulation results show decreasing temperature gradient in the plate with decreasing quenching rate,which leads to weakened inhomogeneous plastic deformation and decreased residual stress.No dynamic precipitation on the grain boundary happens after either cold water cooling or air cooling,however,air cooling leads to dynamic precipitation of Mg-Zn phase on Mn particles around which a low-density precipitate zone develops after aging treatment.Moreover,the fine and densely distributed Mg-Zn precipitates observed after aging treatment of the cold water cooled alloy are replaced by coarse precipitates with low density for the air cooled alloy.Both the low-density precipitate zone near Mn particles and the coarsening of precipitates are the source of the decrease in hardness and tensile properties of the air cooled alloy.The residual stress drops faster than the hardness with decreasing quenching rate,which makes it possible to lower the residual stress without sacrificing too much age-hardening ability of the alloy. 展开更多
关键词 Mg-5Zn-3.5Sn-1Mn-0.5Ca-0.5Cu alloy Solution treatment Quenching rate Residual stress precipitation AGE-HARDENING
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Comprehensive applicability evaluation of four precipitation products at multiple spatiotemporal scales in Northwest China
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作者 WANG Xiangyu XU Min +3 位作者 KANG Shichang LI Xuemei HAN Haidong LI Xingdong 《Journal of Arid Land》 SCIE CSCD 2024年第9期1232-1254,共23页
Precipitation plays a crucial role in the water cycle of Northwest China.Obtaining accurate precipitation data is crucial for regional water resource management,hydrological forecasting,flood control and drought relie... Precipitation plays a crucial role in the water cycle of Northwest China.Obtaining accurate precipitation data is crucial for regional water resource management,hydrological forecasting,flood control and drought relief.Currently,the applicability of multi-source precipitation products for long time series in Northwest China has not been thoroughly evaluated.In this study,precipitation data from 183 meteorological stations in Northwest China from 1979 to 2020 were selected to assess the regional applicability of four precipitation products(the fifth generation of European Centre for Medium-Range Weather Forecasts(ECMWF)atmospheric reanalysis of the global climate(ERA5),Global Precipitation Climatology Centre(GPCC),Climatic Research Unit gridded Time Series Version 4.07(CRU TS v4.07,hereafter CRU),and Tropical Rainfall Measuring Mission(TRMM))based on the following statistical indicators:correlation coefficient,root mean square error(RMSE),relative bias(RB),mean absolute error(MAE),probability of detection(POD),false alarm ratio(FAR),and equitable threat score(ETS).The results showed that precipitation in Northwest China was generally high in the east and low in the west,and exhibited an increasing trend from 1979 to 2020.Compared with the station observations,ERA5 showed a larger spatial distribution difference than the other products.The overall overestimation of multi-year average precipitation was approximately 200.00 mm and the degree of overestimation increased with increasing precipitation intensity.The multi-year average precipitation of GPCC and CRU was relatively close to that of station observations.The trend of annual precipitation of TRMM was overestimated in high-altitude regions and the eastern part of Lanzhou with more precipitation.At the monthly scale,GPCC performed well but underestimated precipitation in the Tarim Basin(RB=-4.11%),while ERA5 and TRMM exhibited poor accuracy in high-altitude regions.ERA5 had a large bias(RB≥120.00%)in winter months and a strong dispersion(RMSE≥35.00 mm)in summer months.TRMM showed a relatively low correlation with station observations in winter months(correlation coefficients≤0.70).The capture performance analysis showed that ERA5,GPCC,and TRMM had lower POD and ETS values and higher FAR values in Northwest China as the precipitation intensity increased.ERA5 showed a high capture performance for small precipitation events and a slower decreasing trend of POD as the precipitation intensity increased.GPCC had the lowest FAR values.TRMM was statistically ineffective for predicting the occurrence of daily precipitation events.The findings provide a reference for data users to select appropriate datasets in Northwest China and for data developers to develop new precipitation products in the future. 展开更多
关键词 precipitation products the fifth generation of European Centre for Medium-Range Weather Forecasts(ECMWF)atmospheric reanalysis of the global climate(ERA5) Global precipitation Climatology Centre(GPCC) Climatic Research Unit gridded Time Series(CRU TS) Tropical Rainfall Measuring Mission(TRMM) applicability evaluation Northwest China
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Synthesis of Polycrystalline Yb:Gd_3Ga_5O_(12) Nanopowders by Homogeneous Precipitation Method
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作者 黄德馨 刘景和 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2010年第1期123-126,共4页
The Ytterbium doped gadolinium gallium garnet [Yb3+:Gd3Ga5O12, Yb:GGG] precursor powders were synthesized via homogeneous precipitation method using Yb2O3, Ga2O3, Gd2O3 and ammonium bicarbonate [NH4HCO3] as precipi... The Ytterbium doped gadolinium gallium garnet [Yb3+:Gd3Ga5O12, Yb:GGG] precursor powders were synthesized via homogeneous precipitation method using Yb2O3, Ga2O3, Gd2O3 and ammonium bicarbonate [NH4HCO3] as precipitator, and ammonium sulfate [(NH4)2SO4] as additive. The evolution of phase composition and micro-structure of the powders were characterized by TG- DTA, XRD, IR, and TEM. The results indicate that all precursor powders completely transform to Yb:GGG phase by calcining at 900 ℃ for 8 h, the resultant powders are well dispersed and have smaller particle size approximately 80 nm owing to the electrostatic effect. 展开更多
关键词 Yb:Gd3Ga5O12 POLYCRYSTALLINE homogeneous precipitation NANOPOWDERS
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The Operational Forecasting of Total Precipitation in Flood Seasons (April to September) of 5 Years (1983-1987)
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作者 汤懋苍 李天时 +1 位作者 张建 李存强 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1989年第3期289-300,共12页
Ⅰ.INTRODUCTION We have discovered that there exists a good corresponding relationship between theanomalous axes of soil temperature at a depth of 1.6m in winter (December to February) andprecipitations in following f... Ⅰ.INTRODUCTION We have discovered that there exists a good corresponding relationship between theanomalous axes of soil temperature at a depth of 1.6m in winter (December to February) andprecipitations in following flood season (Tang et al., 1982a). We have also designed a simplethermodynamical model and applied it to the forecasting of precipitations in the flood season(Tang et al., 1982 b,c). The practical forecast started from 1975. Before 1980, however, therewere only 40-50 stations in China for measuring the soil temperature at a 1.6m depth. Since1980, the stations have been increased to a total of about 180, but no available mean valueshad been obtained from newly added stations before 1982. Therefore the analysis and map-ping of anomalies of soil temperature was not performed until 1983, and from then on theprecision of analysis has been greatly improved. The following is the actual situation of forecast in five years from 1983 to 1987. 展开更多
关键词 of 5 Years April to September The Operational Forecasting of Total precipitation in Flood Seasons
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Assessment of CMIP3-CMIP5 Climate Models Precipitation Projection and Implication of Flood Vulnerability of Bangkok
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作者 Seree Supharatid 《American Journal of Climate Change》 2015年第1期140-162,共23页
Reliable estimates of precipitation are essential for both research and practical applications. CMIP3 and CMIP5 climate simulations provide both historical simulations and future projections of extreme climate. The 20... Reliable estimates of precipitation are essential for both research and practical applications. CMIP3 and CMIP5 climate simulations provide both historical simulations and future projections of extreme climate. The 2011 monsoon season was one of case studies with exceptionally heavy and led to extensive and long-lasting flooding in the Chao Phraya river basin, Thailand. Flooding was exacerbated by the rapid expansion of urban areas into flood plains and was the costliest natural disaster in the country’s history, with direct damages estimated at US$45 billion. The present paper focuses on the precipitation downscaling of CMIP3 and CMIP5 models. The majority of CMIP3 and CMIP5 models overestimate the dry spell (in June and July) and underestimate the peak precipitation (in May and September). The interquartile model range for precipitation, which is spanned by the 25th and 75th quantiles, is closer to the observed data for CMIP5 than CMIP3 models. However, overall results suggest that the performance of CMIP5 models cannot be readily distinguished from of CMIP3 models, although there are clear signals of improvements over Bangkok. The correlation coefficient is found between 0.6 - 0.8, implying that most of the models simulate the mean rainfall reasonably well. Both model generations have approximately the same standard deviation as observed, but more spatial variability and more RMS error are found for the future projections. Use of the Multi Model mean shows continuously increased rainfall from the near future to the far future while the Multi Model Median shows increased rainfall only for the far future. These findings in changing precipitation are discussed through the flood behavior in 2011. Results from flood simulation with several adaptation measures reveal that flood cannot be completely avoided. One of the best practices for highflood risk communities is to raise the house with open space in the first floor. 展开更多
关键词 precipitation DOWNSCALING CMIP3 CMIP5 The 2011 Great FLOOD
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ERA-5降水数据在澜沧江流域高山峡谷地区的适用性研究 被引量:1
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作者 张佳鹏 王加虎 +1 位作者 李丽 陈明霞 《水电能源科学》 北大核心 2021年第1期14-17,5,共5页
以澜沧江流域典型高山峡谷地区为例,首先对最新发布的ERA-5再分析降水产品进行不同时空尺度下的精度评估,发现ERA-5数据与站点数据之间的相关性较高,可较好反映流域降水分布空间变化趋势,但高估了实测降水,存在着较大的系统误差,且误差... 以澜沧江流域典型高山峡谷地区为例,首先对最新发布的ERA-5再分析降水产品进行不同时空尺度下的精度评估,发现ERA-5数据与站点数据之间的相关性较高,可较好反映流域降水分布空间变化趋势,但高估了实测降水,存在着较大的系统误差,且误差有明显的时空变异特性,需经校正才可投入实际应用;然后使用比率偏差校正法对ERA-5进行校正,针对每个包含气象站的ERA-5网格计算其日降水事件对应的校正系数,将校正系数插值到每个网格,从而实现整个研究区域的校正,校正后的ERA-5数据在降水空间分布和数值上的精度均大幅度提升;最后采用水文模型间接评估校正效果,结果表明校正后的ERA-5降水径流模拟精度同样明显高于原始数据。 展开更多
关键词 era-5降水 澜沧江流域 评估 校正 径流模拟
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ERA-5降水数据在雨量站稀疏地区的适用性研究--以缅甸密支那流域为例 被引量:3
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作者 张佳鹏 王加虎 +1 位作者 李丽 陈明霞 《人民长江》 北大核心 2021年第6期36-41,共6页
为探究降水产品在雨量站稀疏地区的适用性,选择位于缅甸的密支那流域作为研究流域,以雨量站数据作为参考数据,评估了ERA-5再分析降水数据的精度;并使用ERA-5数据率定和驱动CREST模型,探究了该数据应用于径流模拟的可行性。结果表明:在... 为探究降水产品在雨量站稀疏地区的适用性,选择位于缅甸的密支那流域作为研究流域,以雨量站数据作为参考数据,评估了ERA-5再分析降水数据的精度;并使用ERA-5数据率定和驱动CREST模型,探究了该数据应用于径流模拟的可行性。结果表明:在整个研究区域内,ERA-5数据和雨量站数据之间的相关程度高,差距较小;而在径流模拟方面,ERA-5数据可以较好地模拟中低水位的日径流过程,对于高水位流量则存在着一定的低估,但不同观测时段的NSCE系数均在0.7以上,总体而言精度仍较高;对于月径流量,该数据在不同观测时段的NSCE系数均大于0.85,相关系数均在0.9以上,能够较好地描述径流的年内变化特征。因此,ERA-5降水数据在一定程度上可以代替雨量站数据作为研究区域的降水数据来源,应用于流域水资源管理、水利工程设计等领域。 展开更多
关键词 再分析降水数据 精度评估 径流模拟 CREST 密支那流域 缺资料地区
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