The Changbaishan volcano is an active and considerably hazardous volcano located on the border of China and North Korea. This paper summarizes a series of geophysical surveys as well as seismological and volcano-obser...The Changbaishan volcano is an active and considerably hazardous volcano located on the border of China and North Korea. This paper summarizes a series of geophysical surveys as well as seismological and volcano-observational networks around the Changbaishan volcanic area. We characterize deep structures related to the Changbaishan volcanic area. The prominent low-velocity anomalies and low-resistance bodies associated with the magma system under the Changbaishan volcano were detected in the crust and upper mantle, and high-velocity anomalies were imaged within the mantle transition zone,suggesting that the origin of the Changbaishan volcano is related to the subducted Pacific slab. However, there exist a few major obstacles for comprehensively elucidating the deep structure of the Changbaishan volcano as well as for the preparedness for and response toward future volcanic unrest and activity. It is essential to collect data from both China and Korean Peninsula to image the deep structure beneath the Changbaishan volcanic area. A multi-disciplinary approach comprising seismological investigations, deformation information from GNSS and InSar, and gravity and magnetotelluric surveying is a reliable manner for imaging high-resolution structures and fluid movement for the spatial distribution and variation of the volcanic magma chamber.An effective volcano-monitoring network system is considerably important to improve hazard assessments and characterize the potential future eruption of the Changbaishan volcano.展开更多
The aim of this study was to characterize the changes in berry anatomy during the development of grape(Vitis vinifera L.,and Vitis vinifera×Vitis labrusca)with different shapes.Paraffin sectioning was used to exa...The aim of this study was to characterize the changes in berry anatomy during the development of grape(Vitis vinifera L.,and Vitis vinifera×Vitis labrusca)with different shapes.Paraffin sectioning was used to examine the structural parameters of the cells.The results revealed that,with the development of berries,the transverse and longitudinal diameters of the flesh cells gradually increased,revealing certain regularity.However,the transverse and longitudinal diameters of the epidermal and sub-epidermal cells were different between varieties,reflecting the specificity of the varieties.The growth of the transverse and longitudinal diameters of the berries was found to be completed in the early stage of development.A combination of correlation analysis and size analysis for each cell layer revealed that,due to the small crosssectional area of the epidermal and sub-epidermal cells,the influence of these cells on the transverse and the longitudinal diameters of the berries would be small.In conclusion,the longitudinal and transverse diameters of the grape berries were mainly determined by the longitudinal and transverse diameters of the flesh cells.The different shapes of the grape berries could mainly be attributed to the different growth rates of the flesh cells in the longitudinal and transverse directions.These different rates of growth led to different lengths and widths of the berry.展开更多
In order to improve understanding of deep convective clouds over the Tibetan Plateau, characteristics of vertical structure of a deep strong convective cloud over Naqu station and a deep weak convective cloud approxim...In order to improve understanding of deep convective clouds over the Tibetan Plateau, characteristics of vertical structure of a deep strong convective cloud over Naqu station and a deep weak convective cloud approximately 100 km to the west of Naqu station, which occurred over 1300-1600 Beijing Time (BT) 9 July 2014 during the Third Tibetan Plateau Atmospheric Science Experiment (TIPEX-Ⅲ), are analyzed, based on multi-source satellite data from TRMM, CloudSat, and Aqua, and radar data from ground-based vertically pointing radars (C-band frequency-modulated continuous-wave radar and KA-band millimeter wave cloud radar). The results are as follows.(1) The horizontal scales of both the deep strong and deep weak convective clouds were small (10-20 km), and their tops were high[15-16 km above sea level (ASL)]. Across the level of 0℃ isotherm in the deep strong convective cloud, the reflectivity increased rapidly, suggesting that the melting process of solid precipitation particles through the 0℃ level played an important role. A bright band located at 5.5 km ASL (i.e., 1 km above ground level) appeared during the period of convection weakening.(2) The reflectivity values from TRMM precipitation radar below 11 km were found to be overestimated compared to those derived from the C-band frequency-modulated continuous-wave radar.(3) Deep convective clouds were mainly ice clouds, and there were rich small ice particles above 10 km, while few large ice particles were found below 10 km. The microphysical processes of deep strong and deep weak convective clouds mainly included mixed-phase process and glaciated process, and the mixed-phase process can be divided into two types:one was the rimming process below the level of -25℃(deep strong convective cloud) or -29℃(deep weak convective cloud) and the other was aggregation and deposition process above that level. The latter process was accompanied with fast increase in ice particle effective radius. The above evidence from space-based and ground-based observational d展开更多
This article aims to build a theory of atmospheric boundary layer turbulence under complex conditions. To achieve this goal, we constructed a multi-site observation and analysis method of atmospheric turbulence based ...This article aims to build a theory of atmospheric boundary layer turbulence under complex conditions. To achieve this goal, we constructed a multi-site observation and analysis method of atmospheric turbulence based on related principles.This method first requires verification for the ergodicity of the full-scale observation of surface-layer turbulence, which proves that eddies within a scale of 60 min during a four-site observation can easily meet ergodicity. Meanwhile, by applying the second-order structure function for the horizontal wind speed turbulence of a single site and upstream and downstream points, we verified the ergodicity of the turbulence observation. Comparing the turbulence spectrum to the second-order structure function for the horizontal wind speed from the four-site observation, a relatively high accordance was observed, proving the reasonability of the multi-site observation. Moreover, compared to the single-site observation, the four-site observation can improve the estimation accuracy of the surface-layer turbulence spectrum and vertical turbulent flux. As a result, we can describe the threedimensional structure of turbulence more accurately and comprehensively by combining analytical data from single-site and four-site observations. In summary, the multi-site turbulence observation method shows that the horizontal and vertical wind turbulence of the Baimiao plateau has a typical structure of a turbulence spectrum with clear spectral gaps. The result is in accordance with the scale of the turbulence spectral gaps obtained from the 6 h data. The horizontal wind speed is under the influence of the terrain, so its spectrum of large-scale eddies has higher fluctuations, but its spectral gaps can still be clearly distinguished. Although the spectral gaps of the temperature spectrum are not distinguishable, they still have the same scale as the spectral gap of the vertical and horizontal turbulence spectrum. Moreover, the temperature spectrum possesses typical structure characteristics of the b展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 41474041 and 41774058)the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDB18000000)
文摘The Changbaishan volcano is an active and considerably hazardous volcano located on the border of China and North Korea. This paper summarizes a series of geophysical surveys as well as seismological and volcano-observational networks around the Changbaishan volcanic area. We characterize deep structures related to the Changbaishan volcanic area. The prominent low-velocity anomalies and low-resistance bodies associated with the magma system under the Changbaishan volcano were detected in the crust and upper mantle, and high-velocity anomalies were imaged within the mantle transition zone,suggesting that the origin of the Changbaishan volcano is related to the subducted Pacific slab. However, there exist a few major obstacles for comprehensively elucidating the deep structure of the Changbaishan volcano as well as for the preparedness for and response toward future volcanic unrest and activity. It is essential to collect data from both China and Korean Peninsula to image the deep structure beneath the Changbaishan volcanic area. A multi-disciplinary approach comprising seismological investigations, deformation information from GNSS and InSar, and gravity and magnetotelluric surveying is a reliable manner for imaging high-resolution structures and fluid movement for the spatial distribution and variation of the volcanic magma chamber.An effective volcano-monitoring network system is considerably important to improve hazard assessments and characterize the potential future eruption of the Changbaishan volcano.
基金The authors are grateful for the National Key Research and Development Program(Grant No.2019YFD1000101)the financial support from the National Natural Science Foundation Project(Grant Nos.31672131 and 31372027)+1 种基金China Agriculture Research System(Grant No.CARS-29)and the Agricultural Science and Technology Innovation Program(Grant No.CAAS-ASTIP-2018-ZFRI).
文摘The aim of this study was to characterize the changes in berry anatomy during the development of grape(Vitis vinifera L.,and Vitis vinifera×Vitis labrusca)with different shapes.Paraffin sectioning was used to examine the structural parameters of the cells.The results revealed that,with the development of berries,the transverse and longitudinal diameters of the flesh cells gradually increased,revealing certain regularity.However,the transverse and longitudinal diameters of the epidermal and sub-epidermal cells were different between varieties,reflecting the specificity of the varieties.The growth of the transverse and longitudinal diameters of the berries was found to be completed in the early stage of development.A combination of correlation analysis and size analysis for each cell layer revealed that,due to the small crosssectional area of the epidermal and sub-epidermal cells,the influence of these cells on the transverse and the longitudinal diameters of the berries would be small.In conclusion,the longitudinal and transverse diameters of the grape berries were mainly determined by the longitudinal and transverse diameters of the flesh cells.The different shapes of the grape berries could mainly be attributed to the different growth rates of the flesh cells in the longitudinal and transverse directions.These different rates of growth led to different lengths and widths of the berry.
基金Supported by the China Meteorological Administration Special Public Welfare Research Fund for the Third Tibetan Plateau Atmospheric Science Experiment(GYHY201406001)National Natural Science Foundation of China(41605107 and 91437104)Basic Research Fund of Chinese Academy of Meteorological Sciences(2015Y006)
文摘In order to improve understanding of deep convective clouds over the Tibetan Plateau, characteristics of vertical structure of a deep strong convective cloud over Naqu station and a deep weak convective cloud approximately 100 km to the west of Naqu station, which occurred over 1300-1600 Beijing Time (BT) 9 July 2014 during the Third Tibetan Plateau Atmospheric Science Experiment (TIPEX-Ⅲ), are analyzed, based on multi-source satellite data from TRMM, CloudSat, and Aqua, and radar data from ground-based vertically pointing radars (C-band frequency-modulated continuous-wave radar and KA-band millimeter wave cloud radar). The results are as follows.(1) The horizontal scales of both the deep strong and deep weak convective clouds were small (10-20 km), and their tops were high[15-16 km above sea level (ASL)]. Across the level of 0℃ isotherm in the deep strong convective cloud, the reflectivity increased rapidly, suggesting that the melting process of solid precipitation particles through the 0℃ level played an important role. A bright band located at 5.5 km ASL (i.e., 1 km above ground level) appeared during the period of convection weakening.(2) The reflectivity values from TRMM precipitation radar below 11 km were found to be overestimated compared to those derived from the C-band frequency-modulated continuous-wave radar.(3) Deep convective clouds were mainly ice clouds, and there were rich small ice particles above 10 km, while few large ice particles were found below 10 km. The microphysical processes of deep strong and deep weak convective clouds mainly included mixed-phase process and glaciated process, and the mixed-phase process can be divided into two types:one was the rimming process below the level of -25℃(deep strong convective cloud) or -29℃(deep weak convective cloud) and the other was aggregation and deposition process above that level. The latter process was accompanied with fast increase in ice particle effective radius. The above evidence from space-based and ground-based observational d
基金supported by the National Natural Science Foundation of China(Grant Nos.42175104&41675014)。
文摘This article aims to build a theory of atmospheric boundary layer turbulence under complex conditions. To achieve this goal, we constructed a multi-site observation and analysis method of atmospheric turbulence based on related principles.This method first requires verification for the ergodicity of the full-scale observation of surface-layer turbulence, which proves that eddies within a scale of 60 min during a four-site observation can easily meet ergodicity. Meanwhile, by applying the second-order structure function for the horizontal wind speed turbulence of a single site and upstream and downstream points, we verified the ergodicity of the turbulence observation. Comparing the turbulence spectrum to the second-order structure function for the horizontal wind speed from the four-site observation, a relatively high accordance was observed, proving the reasonability of the multi-site observation. Moreover, compared to the single-site observation, the four-site observation can improve the estimation accuracy of the surface-layer turbulence spectrum and vertical turbulent flux. As a result, we can describe the threedimensional structure of turbulence more accurately and comprehensively by combining analytical data from single-site and four-site observations. In summary, the multi-site turbulence observation method shows that the horizontal and vertical wind turbulence of the Baimiao plateau has a typical structure of a turbulence spectrum with clear spectral gaps. The result is in accordance with the scale of the turbulence spectral gaps obtained from the 6 h data. The horizontal wind speed is under the influence of the terrain, so its spectrum of large-scale eddies has higher fluctuations, but its spectral gaps can still be clearly distinguished. Although the spectral gaps of the temperature spectrum are not distinguishable, they still have the same scale as the spectral gap of the vertical and horizontal turbulence spectrum. Moreover, the temperature spectrum possesses typical structure characteristics of the b
