This study investigates the distinct impacts of eastern Pacific(EP)and central Pacific(CP)El Niño events on winter shortwave solar radiation(SSR)in southern China,revealing different spatial distributions and und...This study investigates the distinct impacts of eastern Pacific(EP)and central Pacific(CP)El Niño events on winter shortwave solar radiation(SSR)in southern China,revealing different spatial distributions and underlying mechanisms.The results show that,during the developing winter of EP El Niño,significant SSR reductions occur in southwestern China and the east coast of southern China due to a strong,zonally extended Northwest Pacific anticyclone that transports moisture from the tropical Northwest Pacific and North Indian Ocean,while the northeast of southern China experiences a weak increase in SSR.In contrast,during the developing winter of CP El Niño,SSR decreases in the east of southern China with a significant decrease in the lower basin of the Yangtze River but an increase in the west of southern China with a remarkable increase in eastern Yunnan.The pronounced east-west dipole pattern in SSR anomalies is driven by a meridionally elongated Northwest Pacific anticyclone,which enhances northward moisture transport to the east of southern China while leaving western areas drier.Further research reveals that distinct moisture anomalies during the developing winter of EP and CP events result in divergent SSR distributions across southern China,primarily through modulating the total cloud cover.These findings highlight the critical need to differentiate between El Niño types when predicting medium and long-term variability of radiation in southern China.展开更多
This study proposes a novel forecasting framework that simultaneously captures the strong periodicity and irregular meteorological fluctuations inherent in solar radiation time series.Existing approaches typically def...This study proposes a novel forecasting framework that simultaneously captures the strong periodicity and irregular meteorological fluctuations inherent in solar radiation time series.Existing approaches typically define inter-regional correlations using either simple correlation coefficients or distance-based measures when applying spatio-temporal graph neural networks(STGNNs).However,such definitions are prone to generating spurious correlations due to the dominance of periodic structures.To address this limitation,we adopt the Elastic-Band Transform(EBT)to decompose solar radiation into periodic and amplitude-modulated components,which are then modeled independently with separate graph neural networks.The periodic component,characterized by strong nationwide correlations,is learned with a relatively simple architecture,whereas the amplitude-modulated component is modeled with more complex STGNNs that capture climatological similarities between regions.The predictions from the two components are subsequently recombined to yield final forecasts that integrate both periodic patterns and aperiodic variability.The proposed framework is validated with multiple STGNN architectures,and experimental results demonstrate improved predictive accuracy and interpretability compared to conventional methods.展开更多
土地利用类型变化通过改变地表-大气相互作用对区域气候产生影响,了解土地利用类型变化对区域气候的影响有助于未来土地利用规划和制定区域政策,特别是生态环境极端脆弱敏感的干旱半干旱地区。车尔臣河流域位于塔克拉玛干沙漠(TD)东缘,...土地利用类型变化通过改变地表-大气相互作用对区域气候产生影响,了解土地利用类型变化对区域气候的影响有助于未来土地利用规划和制定区域政策,特别是生态环境极端脆弱敏感的干旱半干旱地区。车尔臣河流域位于塔克拉玛干沙漠(TD)东缘,是保护且末县不被塔克拉玛干沙漠吞噬的唯一防线。近20年来,人为活动使当地植被增加、水体面积扩大,但这种变化对区域气候的影响尚不清楚。利用WRF(Weather Research and Forecasting)模式,分别使用2001年和2021年的MODIS MCD12Q16.1(MCD12Q1)版本全球土地利用类型数据集,设置对照实验研究车尔臣河流域土地利用类型变化对2021年7月区域气候的影响。结果表明:车尔臣河流域水体和绿地增加使地表蒸散总值增加了2.95 mm,地面2 m比湿均值增加了2×10^(-4)kg·kg^(-1);水汽的增加使流域南部山坡区域降水增加,流域北部受反气旋性气流控制,降水没有明显变化;地表绿化和水体增加导致的降水量增加不能补充地表蒸散增加损失的水分。台特玛湖面积恢复区域气温显著降低,平均最高温和最低温分别降低1.8℃和1.3℃;台特玛湖以外的区域,地表植被的增加通过调节蒸散、地表反照率和大气长波辐射等多种途径影响气温,使流域北部最高温升高、最低温降低,流域南部最高温降低、最低温升高;总体而言,地表反照率减小造成的地面净辐射增加起主导作用,净辐射平均增加7.35 W·m^(-2),地面平均气温升高0.21℃。车尔臣河流域水体和绿地增加区域向塔克拉玛干沙漠(TD)地区输送了部分水汽,使TD地区5 km以下水汽含量增加,通过调节辐射使TD地区温度升高,其中,大气逆辐射的增加占主导作用,使区域平均气温升高0.3℃;在反气旋性气流控制下,TD地区降水基本没有变化。展开更多
基金funded by a Project from China Southern Power Grid Company Ltd.(Nos.ZBKJXM20232481 and ZBKJXM20232482)。
文摘This study investigates the distinct impacts of eastern Pacific(EP)and central Pacific(CP)El Niño events on winter shortwave solar radiation(SSR)in southern China,revealing different spatial distributions and underlying mechanisms.The results show that,during the developing winter of EP El Niño,significant SSR reductions occur in southwestern China and the east coast of southern China due to a strong,zonally extended Northwest Pacific anticyclone that transports moisture from the tropical Northwest Pacific and North Indian Ocean,while the northeast of southern China experiences a weak increase in SSR.In contrast,during the developing winter of CP El Niño,SSR decreases in the east of southern China with a significant decrease in the lower basin of the Yangtze River but an increase in the west of southern China with a remarkable increase in eastern Yunnan.The pronounced east-west dipole pattern in SSR anomalies is driven by a meridionally elongated Northwest Pacific anticyclone,which enhances northward moisture transport to the east of southern China while leaving western areas drier.Further research reveals that distinct moisture anomalies during the developing winter of EP and CP events result in divergent SSR distributions across southern China,primarily through modulating the total cloud cover.These findings highlight the critical need to differentiate between El Niño types when predicting medium and long-term variability of radiation in southern China.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(RS-2023-00249743).
文摘This study proposes a novel forecasting framework that simultaneously captures the strong periodicity and irregular meteorological fluctuations inherent in solar radiation time series.Existing approaches typically define inter-regional correlations using either simple correlation coefficients or distance-based measures when applying spatio-temporal graph neural networks(STGNNs).However,such definitions are prone to generating spurious correlations due to the dominance of periodic structures.To address this limitation,we adopt the Elastic-Band Transform(EBT)to decompose solar radiation into periodic and amplitude-modulated components,which are then modeled independently with separate graph neural networks.The periodic component,characterized by strong nationwide correlations,is learned with a relatively simple architecture,whereas the amplitude-modulated component is modeled with more complex STGNNs that capture climatological similarities between regions.The predictions from the two components are subsequently recombined to yield final forecasts that integrate both periodic patterns and aperiodic variability.The proposed framework is validated with multiple STGNN architectures,and experimental results demonstrate improved predictive accuracy and interpretability compared to conventional methods.
文摘土地利用类型变化通过改变地表-大气相互作用对区域气候产生影响,了解土地利用类型变化对区域气候的影响有助于未来土地利用规划和制定区域政策,特别是生态环境极端脆弱敏感的干旱半干旱地区。车尔臣河流域位于塔克拉玛干沙漠(TD)东缘,是保护且末县不被塔克拉玛干沙漠吞噬的唯一防线。近20年来,人为活动使当地植被增加、水体面积扩大,但这种变化对区域气候的影响尚不清楚。利用WRF(Weather Research and Forecasting)模式,分别使用2001年和2021年的MODIS MCD12Q16.1(MCD12Q1)版本全球土地利用类型数据集,设置对照实验研究车尔臣河流域土地利用类型变化对2021年7月区域气候的影响。结果表明:车尔臣河流域水体和绿地增加使地表蒸散总值增加了2.95 mm,地面2 m比湿均值增加了2×10^(-4)kg·kg^(-1);水汽的增加使流域南部山坡区域降水增加,流域北部受反气旋性气流控制,降水没有明显变化;地表绿化和水体增加导致的降水量增加不能补充地表蒸散增加损失的水分。台特玛湖面积恢复区域气温显著降低,平均最高温和最低温分别降低1.8℃和1.3℃;台特玛湖以外的区域,地表植被的增加通过调节蒸散、地表反照率和大气长波辐射等多种途径影响气温,使流域北部最高温升高、最低温降低,流域南部最高温降低、最低温升高;总体而言,地表反照率减小造成的地面净辐射增加起主导作用,净辐射平均增加7.35 W·m^(-2),地面平均气温升高0.21℃。车尔臣河流域水体和绿地增加区域向塔克拉玛干沙漠(TD)地区输送了部分水汽,使TD地区5 km以下水汽含量增加,通过调节辐射使TD地区温度升高,其中,大气逆辐射的增加占主导作用,使区域平均气温升高0.3℃;在反气旋性气流控制下,TD地区降水基本没有变化。
