With the development and deployment of observation systems in the ocean,more precise passive and active microwave data are becoming available for the weather forecasting and the climate monitoring.Due to the complicat...With the development and deployment of observation systems in the ocean,more precise passive and active microwave data are becoming available for the weather forecasting and the climate monitoring.Due to the complicated variability of the sea ice concentration(SIC)in the marginal ice zone and the scarcity of high-precision sea ice data,how to use less data to accurately reconstruct the sea ice field has become an urgent problem to be solved.A reconstruction method for gridding observations using the variational optimization technique,called the multi-scale high-order recursive filter(MHRF),which is a combination of Van Vliet fourth-order recursive filter and the three-dimensional variational(3D-VAR)analysis,has been designed in this study to reproduce the refined structure of sea ice field.Compared with the existing spatial multi-scale first-order recursive filter(SMRF)in which left and right filter iterative processes are executed many times,the MHRF scheme only executes the same filter process once to reduce the analysis errors caused by multiple filters and improve the filter precision.Furthermore,the series connected transfer function in the high-order recursive filter is equivalently replaced by the paralleled one,which can carry out the independent filter process in every direction in order to improve the filter efficiency.Experimental results demonstrate that this method possesses a good potential in extracting the observation information to successfully reconstruct the SIC field in computational efficiency.展开更多
This article provides an assessment of the changes in marine climate drivers(hazards),associated impacts,risks,and adaptation to the coastal China zones and seas since the mid 20th century.The results show that:①Mari...This article provides an assessment of the changes in marine climate drivers(hazards),associated impacts,risks,and adaptation to the coastal China zones and seas since the mid 20th century.The results show that:①Marine climate drivers,such as ocean warming,sea level rise,typhoon,storm surges and marine heat waves(MHWs),have increased significantly in strength,frequency and range over the past decades.②Ocean warming has caused substantial changes in marine phenology,species composition,geographical distribution,and frequent occurrences of ecological disasters such as red tides,green tides,and macro-jellyfish outbreaks,while MHWs have induced degradation in tropical coral reefs and major losses in the marine aquaculture industry in the coastal China seas.③Sea level rise threatens the typical habitats of coastal wetlands such as mangrove and estuaries,and exacerbates coastal erosion,seawater intrusion and the impacts of typhoon,storm surges on the coastal flood disasters.④Human activities,such as large-scale reclamation,pollutant discharge,and overfishing,have increased the exposure and vulnerability of China's marine and coastal ecosystems,leading to the low-aging and miniaturization of fishery types,decline of offshore fishery resources,reduction of coastal wetland areas,and degradation of biodiversity and ecosystem stability.⑤Under different climate scenarios such as low and high greenhouse gases emission scenario(RCP 2.6 and 8.5),as the warming and sea level rise in the coastal China seas continue,extreme sea level(ESL)events will occur more frequently,e.g.,by the end of this century,the current once per century ESL events will become annually or even annually less(RCP 8.5)in many coastal areas,such as at Lvsi and Xiamen tidal gauge stations;and the ESL events could pose serious risks on the coastal areas.Finally,the article further discusses the adaptation measures and related uncertain issues to address climate change in the coastal China zones and seas,and puts forward relevant countermeasures and suggestions in order to reduce its negative impacts on the sustainable development of human community.展开更多
基金The National Key Research and Development Program of China under contract Nos 2018YFC1407402 and 2017YFC1404103the National Programme on Global Change and Air-Sea Interaction(GASI-IPOVAI-04)of Chinathe Open Fund Project of Key Laboratory of Marine Environmental Information Technology,Ministry of Natural Resources。
文摘With the development and deployment of observation systems in the ocean,more precise passive and active microwave data are becoming available for the weather forecasting and the climate monitoring.Due to the complicated variability of the sea ice concentration(SIC)in the marginal ice zone and the scarcity of high-precision sea ice data,how to use less data to accurately reconstruct the sea ice field has become an urgent problem to be solved.A reconstruction method for gridding observations using the variational optimization technique,called the multi-scale high-order recursive filter(MHRF),which is a combination of Van Vliet fourth-order recursive filter and the three-dimensional variational(3D-VAR)analysis,has been designed in this study to reproduce the refined structure of sea ice field.Compared with the existing spatial multi-scale first-order recursive filter(SMRF)in which left and right filter iterative processes are executed many times,the MHRF scheme only executes the same filter process once to reduce the analysis errors caused by multiple filters and improve the filter precision.Furthermore,the series connected transfer function in the high-order recursive filter is equivalently replaced by the paralleled one,which can carry out the independent filter process in every direction in order to improve the filter efficiency.Experimental results demonstrate that this method possesses a good potential in extracting the observation information to successfully reconstruct the SIC field in computational efficiency.
基金supported by grants from the National Key Research and Development Program of China [grant numbers 2016YFC1401800,2017YFC1404103,2016YFC1401701,and 2019YFC1510000]the National Natural Science Foundation of China [grant number 41976019]the Tianjin Natural Science Foundation [grant number 18JCQNJC01200]。
基金The research was supported by the National Key R&D Program[Grant number.2017YFA0604902,2017YFA0604903].
文摘This article provides an assessment of the changes in marine climate drivers(hazards),associated impacts,risks,and adaptation to the coastal China zones and seas since the mid 20th century.The results show that:①Marine climate drivers,such as ocean warming,sea level rise,typhoon,storm surges and marine heat waves(MHWs),have increased significantly in strength,frequency and range over the past decades.②Ocean warming has caused substantial changes in marine phenology,species composition,geographical distribution,and frequent occurrences of ecological disasters such as red tides,green tides,and macro-jellyfish outbreaks,while MHWs have induced degradation in tropical coral reefs and major losses in the marine aquaculture industry in the coastal China seas.③Sea level rise threatens the typical habitats of coastal wetlands such as mangrove and estuaries,and exacerbates coastal erosion,seawater intrusion and the impacts of typhoon,storm surges on the coastal flood disasters.④Human activities,such as large-scale reclamation,pollutant discharge,and overfishing,have increased the exposure and vulnerability of China's marine and coastal ecosystems,leading to the low-aging and miniaturization of fishery types,decline of offshore fishery resources,reduction of coastal wetland areas,and degradation of biodiversity and ecosystem stability.⑤Under different climate scenarios such as low and high greenhouse gases emission scenario(RCP 2.6 and 8.5),as the warming and sea level rise in the coastal China seas continue,extreme sea level(ESL)events will occur more frequently,e.g.,by the end of this century,the current once per century ESL events will become annually or even annually less(RCP 8.5)in many coastal areas,such as at Lvsi and Xiamen tidal gauge stations;and the ESL events could pose serious risks on the coastal areas.Finally,the article further discusses the adaptation measures and related uncertain issues to address climate change in the coastal China zones and seas,and puts forward relevant countermeasures and suggestions in order to reduce its negative impacts on the sustainable development of human community.
基金supported by the National Key Research and Development Program of China[grant number 2016YFC1401803]the National Natural Science Foundation of China[grant numbers 41976019 and 42076020]+3 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences[grant number XDA20060502]the open project of the State Key Laboratory of Tropical Oceanography,South China Sea Institute of Oceanology,Chinese Academy of Sciences[grant number LTO1910]the Research Program of the Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)[grant number GML2019ZD0306]the Key Research Program of the Chinese Academy of Sciences[grant number ZDRW-XH-2019-2]。
