采用人工神经网络双向时间序列插补模型,利用缺失数据前后已知的观测数据,插补出短期缺失通量数据;应用人工神经网络环境因子辅助参证模型,利用各种与标量通量存在明显生态学响应关系的环境因子观测资料预测长期缺失通量数据。并结合For...采用人工神经网络双向时间序列插补模型,利用缺失数据前后已知的观测数据,插补出短期缺失通量数据;应用人工神经网络环境因子辅助参证模型,利用各种与标量通量存在明显生态学响应关系的环境因子观测资料预测长期缺失通量数据。并结合Forest Site Mongolia森林生态定位站2003年的NEE观测资料,人为剔除一定比例的数据,分别用平均昼夜法(MDV)和非线形回归法(MM-S)以及2种人工神经网络模型将剔除的数据补齐,用各种插补方法得到的结果与原NEE观测资料进行对比。结果表明:2种基于人工神经网络的插补模型对通量观测缺失数据能够进行较好的插补。展开更多
Satellite-derived surface radiative fluxes have been recently improved and extended.However,the accuracy of recent satellite-derived surface radiative fluxes in the Arctic is not well characterized.Here,the authors as...Satellite-derived surface radiative fluxes have been recently improved and extended.However,the accuracy of recent satellite-derived surface radiative fluxes in the Arctic is not well characterized.Here,the authors assess the accuracy of the net surface radiative flux （NETSRF） in the Arctic,focusing on the ice-covered ocean,for three satellite products against four in situ measurements collected from different areas in the Arctic.The three satellite products are the Surface Radiation Budget project （SRB）,the International Satellite Cloud Climatology Project （ISCCP）,and the Extended AVHRR Polar Pathfinder version-2 （APP-x）.Our comparisons suggest that：（1） in terms of the overall bias,root-mean-square error,and correlation,the NETSRF of ISCCP is closer to in situ observations than that of SRB and APP-x;（2） in terms of the diurnal variation of the biases,it is not very clear which satellite product is superior to the others;and （3） in terms of the interannual variability of the bias,the NETSRF of ISCCP is more accurate than that of SRB and APP-x.This comparison may provide useful guidance to the community as to which data-set may provide the smallest bias in NETSRF展开更多
As the Earth entering into the Anthropocene, global sustainable development requires ecological research to evolve into the large-scale, quantitative, and predictive era. It necessitates a revolution of ecological obs...As the Earth entering into the Anthropocene, global sustainable development requires ecological research to evolve into the large-scale, quantitative, and predictive era. It necessitates a revolution of ecological observation technology and a long-term accumulation of scientific data. The ecosystem flux tower observation technology is the right one to meet this requirement. However, the unique advantages and potential values of global-scale flux tower observation are still not fully appreciated. Reviewing the development history of global meteorological observation and its scientific contributions to the society, we can get an important enlightenment to re-cognize the scientific mission of flux observation.展开更多
文摘采用人工神经网络双向时间序列插补模型,利用缺失数据前后已知的观测数据,插补出短期缺失通量数据;应用人工神经网络环境因子辅助参证模型,利用各种与标量通量存在明显生态学响应关系的环境因子观测资料预测长期缺失通量数据。并结合Forest Site Mongolia森林生态定位站2003年的NEE观测资料,人为剔除一定比例的数据,分别用平均昼夜法(MDV)和非线形回归法(MM-S)以及2种人工神经网络模型将剔除的数据补齐,用各种插补方法得到的结果与原NEE观测资料进行对比。结果表明:2种基于人工神经网络的插补模型对通量观测缺失数据能够进行较好的插补。
基金supported by the National Major Research High Performance Computing Program of China[grant number 2016YFB0200800]the National Natural Science Foundation of China[grant number 41676185]the NOAA Climate Program Office[grant number NA14OAR4310216]
文摘Satellite-derived surface radiative fluxes have been recently improved and extended.However,the accuracy of recent satellite-derived surface radiative fluxes in the Arctic is not well characterized.Here,the authors assess the accuracy of the net surface radiative flux （NETSRF） in the Arctic,focusing on the ice-covered ocean,for three satellite products against four in situ measurements collected from different areas in the Arctic.The three satellite products are the Surface Radiation Budget project （SRB）,the International Satellite Cloud Climatology Project （ISCCP）,and the Extended AVHRR Polar Pathfinder version-2 （APP-x）.Our comparisons suggest that：（1） in terms of the overall bias,root-mean-square error,and correlation,the NETSRF of ISCCP is closer to in situ observations than that of SRB and APP-x;（2） in terms of the diurnal variation of the biases,it is not very clear which satellite product is superior to the others;and （3） in terms of the interannual variability of the bias,the NETSRF of ISCCP is more accurate than that of SRB and APP-x.This comparison may provide useful guidance to the community as to which data-set may provide the smallest bias in NETSRF
基金Science and Technology Service Network Initiative of the Chinese Academy of Sciences(KFJ-SW-STS-169)National Natural Science Foundation of China(41671045 and 31600347)
文摘As the Earth entering into the Anthropocene, global sustainable development requires ecological research to evolve into the large-scale, quantitative, and predictive era. It necessitates a revolution of ecological observation technology and a long-term accumulation of scientific data. The ecosystem flux tower observation technology is the right one to meet this requirement. However, the unique advantages and potential values of global-scale flux tower observation are still not fully appreciated. Reviewing the development history of global meteorological observation and its scientific contributions to the society, we can get an important enlightenment to re-cognize the scientific mission of flux observation.
