Climate sequences can be applied to defining sensitive climate zones, and then the mining of spatio-temporal teleconnection patterns is useful for learning from the past and preparing for the future. However, scale-de...Climate sequences can be applied to defining sensitive climate zones, and then the mining of spatio-temporal teleconnection patterns is useful for learning from the past and preparing for the future. However, scale-dependency in this kind of pattern is still not well handled by existing work. Therefore, in this study, the multi-scale regionalization is embedded into the spatio-temporal teleconnection pattern mining between anomalous sea and land climatic events. A modified scale-space clustering algorithm is first developed to group climate sequences into multi-scale climate zones. Then, scale variance analysis method is employed to identify climate zones at characteristic scales, indicating the main characteristics of geographical phenomena. Finally, by using the climate zones identified at characteristic scales, a time association rule mining algorithm based on sliding time windows is employed to discover spatio-temporal teleconnection patterns. Experiments on sea surface temperature, sea level pressure, land precipitation and land temperature datasets show that many patterns obtained by the multi-scale approach are coincident with prior knowledge, indicating that this method is effective and reasonable. In addition, some unknown teleconnection patterns discovered from the multi-scale approach can be further used to guide the prediction of land climate.展开更多
Using European Centre for Medium-Range Weather Forecasts Reanalysis V5(ERA5)reanalysis data,this study investigated the reconstruction effects of various climate variabilities on surface wind speed in China from 1979 ...Using European Centre for Medium-Range Weather Forecasts Reanalysis V5(ERA5)reanalysis data,this study investigated the reconstruction effects of various climate variabilities on surface wind speed in China from 1979 to 2022.The results indicated that the reconstructed annual mean wind speed and the standard deviation of the annual mean wind speed,utilizing various climate variability indices,exhibited similar spatial modes to the reanalysis data,with spatial correlation coefficients of 0.99 and 0.94,respectively.In the reconstruction of six major wind power installed capacity provinces/autonomous regions in China,the effects were notably good for Hebei and Shanxi provinces,with the correlation coefficients for the interannual regional average wind speed time series being 0.65 and 0.64,respectively.The reconstruction effects of surface wind speed differed across seasons,with spring and summer reconstructions showing the highest correlation with reanalysis data.The correlation coefficients for all seasons across most regions in China ranged between 0.4 and 0.8.Among the reconstructed seasonal wind speeds for the six provinces/autonomous regions,Shanxi Province in spring exhibited the highest correlation with the reanalysis,with a coefficient of 0.61.The large-scale climate variability indices showed good reconstruction effects on the annual mean wind speed in China,and could explain the interannual variability trends of surface wind speed in most regions of China,particularly in the main wind energy provinces/autonomous regions.展开更多
Climate variability has become a decisive factor for the crop yields in Sub-Saharan African countries. Inter-annual variability in rainfall has been the key climatic element that determines the success of agriculture ...Climate variability has become a decisive factor for the crop yields in Sub-Saharan African countries. Inter-annual variability in rainfall has been the key climatic element that determines the success of agriculture in this region.From an analysis of recent rainfall conditions in West Africa,FAO(2001) concluded that a long-term change in rainfall has occurred in the semi-arid and sub-humid zones of West Africa.Thus,this study aims at assessing the vulnerability of crop yields to inter-annual variability in rainfall in sub-Saharan African countries taking Nigeria as a case study.A time series of the averaged value of the 12-Month Weighted Anomaly Standardized Precipita-展开更多
【目的】怒江山茶(Camellia saluenensis Stapf ex Bean)是观赏茶花中叶片最小的物种,株型矮小、紧凑、美观,是极具园林应用潜力的观赏树种。未来温室效应增强导致怒江山茶的适生区域发生变化,因此怒江山茶的潜在适生区研究可为其引种...【目的】怒江山茶(Camellia saluenensis Stapf ex Bean)是观赏茶花中叶片最小的物种,株型矮小、紧凑、美观,是极具园林应用潜力的观赏树种。未来温室效应增强导致怒江山茶的适生区域发生变化,因此怒江山茶的潜在适生区研究可为其引种栽培和保护性开发提供科学依据。【方法】基于129条怒江山茶的标本信息,通过生态位模型(MaxEnt模型)和ArcGIS软件,模拟怒江山茶在中国1970—2000年间及未来4个时期(2030s、2050s、2070s、2090s)不同气候条件下的分布情况,探究其适生范围和主导气候因子。【结果】(1)历史基准期,怒江山茶的潜在适生区面积为3.80×10^(5)km^(2),占中国陆地面积的3.94%,主要分布于云南和四川;MaxEnt型ROC曲线的AUC值为0.99,表明模型精度较高,预测结果较好。(2)19个气候变量中,季节性温度变化(B4)对怒江山茶地理分布状况影响最大。(3)未来时期,怒江山茶的适生区范围有所增加。低适生区变化最为明显,有逐渐向西南和东北方向延伸趋势。【结论】怒江山茶在中国的潜在适生区有所扩大,但主要稳定在滇中及金沙江流域,因此可将滇中、金沙江流域的怒江山茶筛选为核心种质,以期推进怒江山茶的引种栽培及园林应用。展开更多
Functional traits, specifically leaf functional traits, are core-topics to explore importance to the invasion success of invasive plant species. This study aims to address the differences in leaf functional traits and...Functional traits, specifically leaf functional traits, are core-topics to explore importance to the invasion success of invasive plant species. This study aims to address the differences in leaf functional traits and their corresponding variability of the invasive tree staghorn sumac Rhus typhina L. with different invasion success, including lower and higher invasion success, in two climatic regions in North China, including a warm temperate region and a cold temperate region. No significant differences were found for leaf functional traits of staghorn sumac across different invasion success. However, the variability of leaf chlorophyll and nitrogen concentrations of staghorn sumac under higher invasion success were approximately 66.023% and 68.615% higher than those under lower invasion success, respectively. The leaf chlorophyll and nitrogen concentrations of staghorn sumac in the warm temperate region were approximately 18.432% and 16.337% higher than those in cold temperate region, respectively. The variability of specific leaf area of staghorn sumac in warm temperate region was approximately 59.802% higher than that in cold temperate region. Accordingly, leaf chlorophyll and N concentrations as well as specific leaf area of staghorn sumac and their corresponding variability may play an essential role in shaping ecological success of studied invader along a climatic gradient.展开更多
基金Projects(41601424,41171351)supported by the National Natural Science Foundation of ChinaProject(2012CB719906)supported by the National Basic Research Program of China(973 Program)+2 种基金Project(14JJ1007)supported by the Hunan Natural Science Fund for Distinguished Young Scholars,ChinaProject(2017M610486)supported by the China Postdoctoral Science FoundationProjects(2017YFB0503700,2017YFB0503601)supported by the National Key Research and Development Foundation of China
文摘Climate sequences can be applied to defining sensitive climate zones, and then the mining of spatio-temporal teleconnection patterns is useful for learning from the past and preparing for the future. However, scale-dependency in this kind of pattern is still not well handled by existing work. Therefore, in this study, the multi-scale regionalization is embedded into the spatio-temporal teleconnection pattern mining between anomalous sea and land climatic events. A modified scale-space clustering algorithm is first developed to group climate sequences into multi-scale climate zones. Then, scale variance analysis method is employed to identify climate zones at characteristic scales, indicating the main characteristics of geographical phenomena. Finally, by using the climate zones identified at characteristic scales, a time association rule mining algorithm based on sliding time windows is employed to discover spatio-temporal teleconnection patterns. Experiments on sea surface temperature, sea level pressure, land precipitation and land temperature datasets show that many patterns obtained by the multi-scale approach are coincident with prior knowledge, indicating that this method is effective and reasonable. In addition, some unknown teleconnection patterns discovered from the multi-scale approach can be further used to guide the prediction of land climate.
基金the National Natural Science Foundation of China(42176243)。
文摘Using European Centre for Medium-Range Weather Forecasts Reanalysis V5(ERA5)reanalysis data,this study investigated the reconstruction effects of various climate variabilities on surface wind speed in China from 1979 to 2022.The results indicated that the reconstructed annual mean wind speed and the standard deviation of the annual mean wind speed,utilizing various climate variability indices,exhibited similar spatial modes to the reanalysis data,with spatial correlation coefficients of 0.99 and 0.94,respectively.In the reconstruction of six major wind power installed capacity provinces/autonomous regions in China,the effects were notably good for Hebei and Shanxi provinces,with the correlation coefficients for the interannual regional average wind speed time series being 0.65 and 0.64,respectively.The reconstruction effects of surface wind speed differed across seasons,with spring and summer reconstructions showing the highest correlation with reanalysis data.The correlation coefficients for all seasons across most regions in China ranged between 0.4 and 0.8.Among the reconstructed seasonal wind speeds for the six provinces/autonomous regions,Shanxi Province in spring exhibited the highest correlation with the reanalysis,with a coefficient of 0.61.The large-scale climate variability indices showed good reconstruction effects on the annual mean wind speed in China,and could explain the interannual variability trends of surface wind speed in most regions of China,particularly in the main wind energy provinces/autonomous regions.
文摘Climate variability has become a decisive factor for the crop yields in Sub-Saharan African countries. Inter-annual variability in rainfall has been the key climatic element that determines the success of agriculture in this region.From an analysis of recent rainfall conditions in West Africa,FAO(2001) concluded that a long-term change in rainfall has occurred in the semi-arid and sub-humid zones of West Africa.Thus,this study aims at assessing the vulnerability of crop yields to inter-annual variability in rainfall in sub-Saharan African countries taking Nigeria as a case study.A time series of the averaged value of the 12-Month Weighted Anomaly Standardized Precipita-
文摘【目的】怒江山茶(Camellia saluenensis Stapf ex Bean)是观赏茶花中叶片最小的物种,株型矮小、紧凑、美观,是极具园林应用潜力的观赏树种。未来温室效应增强导致怒江山茶的适生区域发生变化,因此怒江山茶的潜在适生区研究可为其引种栽培和保护性开发提供科学依据。【方法】基于129条怒江山茶的标本信息,通过生态位模型(MaxEnt模型)和ArcGIS软件,模拟怒江山茶在中国1970—2000年间及未来4个时期(2030s、2050s、2070s、2090s)不同气候条件下的分布情况,探究其适生范围和主导气候因子。【结果】(1)历史基准期,怒江山茶的潜在适生区面积为3.80×10^(5)km^(2),占中国陆地面积的3.94%,主要分布于云南和四川;MaxEnt型ROC曲线的AUC值为0.99,表明模型精度较高,预测结果较好。(2)19个气候变量中,季节性温度变化(B4)对怒江山茶地理分布状况影响最大。(3)未来时期,怒江山茶的适生区范围有所增加。低适生区变化最为明显,有逐渐向西南和东北方向延伸趋势。【结论】怒江山茶在中国的潜在适生区有所扩大,但主要稳定在滇中及金沙江流域,因此可将滇中、金沙江流域的怒江山茶筛选为核心种质,以期推进怒江山茶的引种栽培及园林应用。
基金Project(31300343)supported by the National Natural Science Foundation of ChinaProject(Y20160023)supported by Open Science Research Fund of State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,China+1 种基金Project supported by Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),ChinaProject supported by Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment
文摘Functional traits, specifically leaf functional traits, are core-topics to explore importance to the invasion success of invasive plant species. This study aims to address the differences in leaf functional traits and their corresponding variability of the invasive tree staghorn sumac Rhus typhina L. with different invasion success, including lower and higher invasion success, in two climatic regions in North China, including a warm temperate region and a cold temperate region. No significant differences were found for leaf functional traits of staghorn sumac across different invasion success. However, the variability of leaf chlorophyll and nitrogen concentrations of staghorn sumac under higher invasion success were approximately 66.023% and 68.615% higher than those under lower invasion success, respectively. The leaf chlorophyll and nitrogen concentrations of staghorn sumac in the warm temperate region were approximately 18.432% and 16.337% higher than those in cold temperate region, respectively. The variability of specific leaf area of staghorn sumac in warm temperate region was approximately 59.802% higher than that in cold temperate region. Accordingly, leaf chlorophyll and N concentrations as well as specific leaf area of staghorn sumac and their corresponding variability may play an essential role in shaping ecological success of studied invader along a climatic gradient.
