基于火灾信息资源管理系统(Fire Information for Resource Management System,FIRMS)MODIS(Moderate-resolution Imaging Spectroradiometer)与VIIRS(Visible Infrared Imaging Radiometer)的活跃火位置数据,按照2000—2018年不同时间...基于火灾信息资源管理系统(Fire Information for Resource Management System,FIRMS)MODIS(Moderate-resolution Imaging Spectroradiometer)与VIIRS(Visible Infrared Imaging Radiometer)的活跃火位置数据,按照2000—2018年不同时间(年、月、时)和空间(国家)尺度分析了北极地区活跃火动态变化,旨在为活跃火的预测和管理提供依据。研究结果表明:(1)2012—2018年,MODIS C6(MODIS Near Real-time 1 km active fire products,MCD14DL)与VIIRS V1(VIIRS Near Real-time 375 m active fire products,VNP14-IMGTDL_NRT)活跃火频次趋势一致,最大值与最小值分别出现在2013年与2015年;(2)北极地区活跃火频次累计最多的国家是俄罗斯,最少的国家是挪威,两套产品年际变化在不同国家特征颇为相似;(3)北极地区7国(俄罗斯、美国、加拿大、丹麦、挪威、瑞典和芬兰)活跃火现象主要集中在6—8月,活跃火观测时段主要集中在各国当地时间12时左右。展开更多
High Mountain Asia(HMA) region contains the world’s highest peaks and the largest concentration of glaciers except for the polar regions, making it sensitive to global climate change. In the context of global warming...High Mountain Asia(HMA) region contains the world’s highest peaks and the largest concentration of glaciers except for the polar regions, making it sensitive to global climate change. In the context of global warming, most glaciers in the HMA show various degrees of negative mass balance,while some show positive or near-neutral balance. Many studies have reported that spatial heterogeneity in glacier mass balance is strongly related to a combination of climate parameters. However, this spatial heterogeneity may vary according to the dynamic patterns of climate change at regional or continental scale. The reasons for this may be related to non-climatic factors. To understand the mechanisms by which spatial heterogeneity forms, it is necessary to establish the relationships between glacier mass balance and environmental factors related to topography and morphology. In this study, climate, topography,morphology, and other environmental factors are investigated. Geodetector and linear regression analysis were used to explore the driving factors of spatial variability of glacier mass balance in the HMA by using elevation change data during 2000–2016. The results show that the coverage of supraglacial debris is an essential factor affecting the spatial heterogeneity of glacier mass balance, followed by climatic factors and topographic factors, especially the median elevation and slope in the HMA. There are some differences among mountain regions and the explanatory power of climatic factors on the spatial differentiation of glacier mass balance in each mountain region is weak, indicating that climatic background of each mountain region is similar. Therefore, under similar climatic backgrounds, the median elevation and slope are most correlated with glacier mass balance. The interaction of various factors is enhanced, but no unified interaction factor plays a primary role. Topographic and morphological factors also control the spatial heterogeneity of glacier mass balance by influencing its sensitivity to climate change. In conclusion,geodetector method provides an objective framework for revealing the factors controlling glacier mass balance.展开更多
文摘基于火灾信息资源管理系统(Fire Information for Resource Management System,FIRMS)MODIS(Moderate-resolution Imaging Spectroradiometer)与VIIRS(Visible Infrared Imaging Radiometer)的活跃火位置数据,按照2000—2018年不同时间(年、月、时)和空间(国家)尺度分析了北极地区活跃火动态变化,旨在为活跃火的预测和管理提供依据。研究结果表明:(1)2012—2018年,MODIS C6(MODIS Near Real-time 1 km active fire products,MCD14DL)与VIIRS V1(VIIRS Near Real-time 375 m active fire products,VNP14-IMGTDL_NRT)活跃火频次趋势一致,最大值与最小值分别出现在2013年与2015年;(2)北极地区活跃火频次累计最多的国家是俄罗斯,最少的国家是挪威,两套产品年际变化在不同国家特征颇为相似;(3)北极地区7国(俄罗斯、美国、加拿大、丹麦、挪威、瑞典和芬兰)活跃火现象主要集中在6—8月,活跃火观测时段主要集中在各国当地时间12时左右。
基金supported by the National Natural Science Foundation of China(42071085,41701087)the Open Project of the State Key Laboratory of Cryospheric Science(SKLCS 2020-10)。
文摘High Mountain Asia(HMA) region contains the world’s highest peaks and the largest concentration of glaciers except for the polar regions, making it sensitive to global climate change. In the context of global warming, most glaciers in the HMA show various degrees of negative mass balance,while some show positive or near-neutral balance. Many studies have reported that spatial heterogeneity in glacier mass balance is strongly related to a combination of climate parameters. However, this spatial heterogeneity may vary according to the dynamic patterns of climate change at regional or continental scale. The reasons for this may be related to non-climatic factors. To understand the mechanisms by which spatial heterogeneity forms, it is necessary to establish the relationships between glacier mass balance and environmental factors related to topography and morphology. In this study, climate, topography,morphology, and other environmental factors are investigated. Geodetector and linear regression analysis were used to explore the driving factors of spatial variability of glacier mass balance in the HMA by using elevation change data during 2000–2016. The results show that the coverage of supraglacial debris is an essential factor affecting the spatial heterogeneity of glacier mass balance, followed by climatic factors and topographic factors, especially the median elevation and slope in the HMA. There are some differences among mountain regions and the explanatory power of climatic factors on the spatial differentiation of glacier mass balance in each mountain region is weak, indicating that climatic background of each mountain region is similar. Therefore, under similar climatic backgrounds, the median elevation and slope are most correlated with glacier mass balance. The interaction of various factors is enhanced, but no unified interaction factor plays a primary role. Topographic and morphological factors also control the spatial heterogeneity of glacier mass balance by influencing its sensitivity to climate change. In conclusion,geodetector method provides an objective framework for revealing the factors controlling glacier mass balance.
