2015 Vol. 37, No. 7
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2015, 37(7): .
Abstract:
2015, 37(7): 1-14.
Abstract:
The Tectonic Map of Indian Ocean(1:15 000 000) is compiled to reflect the integrated geology,geomorphology,geophysics,and resource character of Indian Ocean. It is based on newly updated geophysical data,and combines materials obtained through COMRA cruises. The map aims to provide theory support for promoting the research of Indian Ocean tectonic evolution and resource distribution. The compiling methods,data,map content,and tectonic division is introduced in this paper. This paper further analyzed the tectonic pattern of Indian Ocean,which is recognized as various micro-continents,multiple spreading episodes,enriched oceanic plateaus and aseismic ridges,and λ-pattern mid-ocean ridges. Based on previous studies,three stages of tectonic evolution of Indian Ocean is revealed: (1)Breakup of Gondwana Continent and initial seafloor spreading (Jurassic-Mid Cretaceous),(2) seafloor spreading accompanied with spreading center jump (Mid Cretaceous-early Paleogene),and (3) closing of Neo-Tethys Ocean and rifting of East African Rift (Cenozoic). The modern pattern of various micro-continents,multiple spreading episodes,and λ-pattern mid-ocean ridges took shape in early Paleogene.
The Tectonic Map of Indian Ocean(1:15 000 000) is compiled to reflect the integrated geology,geomorphology,geophysics,and resource character of Indian Ocean. It is based on newly updated geophysical data,and combines materials obtained through COMRA cruises. The map aims to provide theory support for promoting the research of Indian Ocean tectonic evolution and resource distribution. The compiling methods,data,map content,and tectonic division is introduced in this paper. This paper further analyzed the tectonic pattern of Indian Ocean,which is recognized as various micro-continents,multiple spreading episodes,enriched oceanic plateaus and aseismic ridges,and λ-pattern mid-ocean ridges. Based on previous studies,three stages of tectonic evolution of Indian Ocean is revealed: (1)Breakup of Gondwana Continent and initial seafloor spreading (Jurassic-Mid Cretaceous),(2) seafloor spreading accompanied with spreading center jump (Mid Cretaceous-early Paleogene),and (3) closing of Neo-Tethys Ocean and rifting of East African Rift (Cenozoic). The modern pattern of various micro-continents,multiple spreading episodes,and λ-pattern mid-ocean ridges took shape in early Paleogene.
2015, 37(7): 15-21.
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Flood and tide features in Minjiang River tidal reach are analyzed and a high-resolution flood-tide coupled model which used high-resolution GIS data for Minjiang Estuary with the highest grid resolution of 50 to 100 m at key areas has been established in this paper. Unstructured triangular mesh that can realize 50 to 100 m' grid resolution at key areas is employed in the model. Zhuqi section has been chosen for flood boundary,and three numerical experiments have been conducted for June 6 2006 flood process. The experiments' results indicated that,when coupled with tide and flood,the simulation of each tide gauge agree very well with measured data compared with model results only with flood or tide; the original tidal features have been changed at the different sections in Minjiang River tidal reach by the flood signals,obvious flood characteristics have been shown in Wenshanli and Jiefang Bridge station,flood-tidal mixed characteristics have been shown in Xianan,Baiyantan and Guantou station; the strong interaction between tide and flood occurred in the watercourse (from Xiannan in South Channel to Guantou) because the current velocity is reduced during high water time but increasing during low water time.
Flood and tide features in Minjiang River tidal reach are analyzed and a high-resolution flood-tide coupled model which used high-resolution GIS data for Minjiang Estuary with the highest grid resolution of 50 to 100 m at key areas has been established in this paper. Unstructured triangular mesh that can realize 50 to 100 m' grid resolution at key areas is employed in the model. Zhuqi section has been chosen for flood boundary,and three numerical experiments have been conducted for June 6 2006 flood process. The experiments' results indicated that,when coupled with tide and flood,the simulation of each tide gauge agree very well with measured data compared with model results only with flood or tide; the original tidal features have been changed at the different sections in Minjiang River tidal reach by the flood signals,obvious flood characteristics have been shown in Wenshanli and Jiefang Bridge station,flood-tidal mixed characteristics have been shown in Xianan,Baiyantan and Guantou station; the strong interaction between tide and flood occurred in the watercourse (from Xiannan in South Channel to Guantou) because the current velocity is reduced during high water time but increasing during low water time.
2015, 37(7): 22-32.
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The influence of the different melting rate of Greenland ice sheet on sea level of the global and regional ocean are studied based on POP model under the RCP4.5 scenario for the 21st century. In the 21st century,the low melting rate of Greenland ice sheet has small influence on the global and regional sea level variations,which mainly due to the meridional overturning flow doesn't weak under the low melting rate of Greenland ice sheet in the Atlantic. The high melting rate will have notably effect on the dynamic and steric sea level in the Atlantic,the Arctic and Antarctic Circumpolar Current (ACC). The dynamic sea level will significantly rise in the north Atlantic subpolar Ocean,tropical Atlantic Ocean,the south Atlantic subtropical and Arctic Ocean,which will rise fast in ocean of southern Greenland and along the coast of North America,that is due to notable weakened of the meridional overturning flow caused by strengthen stratification of the upper ocean and deep convection weakened because of a lot of fresh water input Greenland nearby ocean in the high rate of melting of Greenland ice sheet,namely the labrad or current will strengthen,the Gulf Stream and the north Atlantic current weakened. The thermosteric sea level will significantly decline in the Arctic ocean,the ocean of the southern Greenland and the Atlantic subtropical ocean,while which obviously rise the tropical Atlantic ocean and the Gulf Stream. Meanwhile the halosteric sea level change will be opposite to the thermosteric sea level. The steric sea level showed change due to the water is cooling and thin in the north Atlantic subpolar ocean,the weakened of the Atlantic meridional overturning flow and thermohaline circulation caused by input of lot of low temperature and low salt water in the 21st century.
The influence of the different melting rate of Greenland ice sheet on sea level of the global and regional ocean are studied based on POP model under the RCP4.5 scenario for the 21st century. In the 21st century,the low melting rate of Greenland ice sheet has small influence on the global and regional sea level variations,which mainly due to the meridional overturning flow doesn't weak under the low melting rate of Greenland ice sheet in the Atlantic. The high melting rate will have notably effect on the dynamic and steric sea level in the Atlantic,the Arctic and Antarctic Circumpolar Current (ACC). The dynamic sea level will significantly rise in the north Atlantic subpolar Ocean,tropical Atlantic Ocean,the south Atlantic subtropical and Arctic Ocean,which will rise fast in ocean of southern Greenland and along the coast of North America,that is due to notable weakened of the meridional overturning flow caused by strengthen stratification of the upper ocean and deep convection weakened because of a lot of fresh water input Greenland nearby ocean in the high rate of melting of Greenland ice sheet,namely the labrad or current will strengthen,the Gulf Stream and the north Atlantic current weakened. The thermosteric sea level will significantly decline in the Arctic ocean,the ocean of the southern Greenland and the Atlantic subtropical ocean,while which obviously rise the tropical Atlantic ocean and the Gulf Stream. Meanwhile the halosteric sea level change will be opposite to the thermosteric sea level. The steric sea level showed change due to the water is cooling and thin in the north Atlantic subpolar ocean,the weakened of the Atlantic meridional overturning flow and thermohaline circulation caused by input of lot of low temperature and low salt water in the 21st century.
2015, 37(7): 33-40.
Abstract:
Based on the National Center for Environmental Prediction (NCEP) reanalysis data, Hadley Sea Surface Temperature (SST) and so on, this thesis analysed the mechanism of the autumn Atlantic SSTA effecting on the winter high altitude circulation. The research results are as follows:(1)There is an interaction between North Atlantic SSTA and the atmospheric circulation anomaly; (2)The autumn Atlantic SSTA has good continuity. Due to the continuity of the autumn SSTA in North Atlantic, the "positive-negative-positive (+-+)" distribution of North Atlantic SSTA leads to larger December 500 hPa geopotential height over the Barents Sea;(3)Under the sea surface wind anomaly (SSWA) actions, the feedback mechanism and wind-evaporation-SSTA can benefit the ‘+-+’ SSTA lasting and the feedback to atmospheric circulation anomaly; (4) The negative SSTA moves easterly from October to December, and the stronger evaporation, because of the same wind direction of the SSWA and background wind, produces stronger up-vertical movement. With the positive precipitation area moving easterly from Western Europe, the latent heat transport to the Barents Sea along with the southeast airflow in front of the low trough, promotes the development of the Ridge. Research shows the SSTA and atmospheric circulation anomaly can be affected by autumn Atlantic SSTA through the periodic air-sea interaction mechanism and the winter climate change in Northeast China produces a corresponding change.
Based on the National Center for Environmental Prediction (NCEP) reanalysis data, Hadley Sea Surface Temperature (SST) and so on, this thesis analysed the mechanism of the autumn Atlantic SSTA effecting on the winter high altitude circulation. The research results are as follows:(1)There is an interaction between North Atlantic SSTA and the atmospheric circulation anomaly; (2)The autumn Atlantic SSTA has good continuity. Due to the continuity of the autumn SSTA in North Atlantic, the "positive-negative-positive (+-+)" distribution of North Atlantic SSTA leads to larger December 500 hPa geopotential height over the Barents Sea;(3)Under the sea surface wind anomaly (SSWA) actions, the feedback mechanism and wind-evaporation-SSTA can benefit the ‘+-+’ SSTA lasting and the feedback to atmospheric circulation anomaly; (4) The negative SSTA moves easterly from October to December, and the stronger evaporation, because of the same wind direction of the SSWA and background wind, produces stronger up-vertical movement. With the positive precipitation area moving easterly from Western Europe, the latent heat transport to the Barents Sea along with the southeast airflow in front of the low trough, promotes the development of the Ridge. Research shows the SSTA and atmospheric circulation anomaly can be affected by autumn Atlantic SSTA through the periodic air-sea interaction mechanism and the winter climate change in Northeast China produces a corresponding change.
2015, 37(7): 41-53.
Abstract:
Using the Ensemble Adjustment Kalman Filter (EAKF),two kinds of oceanic satellite observations,namely sea surface temperature (SST) and sea level anomaly (SLA),had been assimilated into the ocean model component of the FIO-ESM (First Institute of Oceanography Earth System Model version 1.0). We analyzed the differences of the atmospheric circulation,specific humidity,cloud fraction,and precipitation in tropical between the assimilation and no assimilation experiment,to investigate the impacts of ocean data assimilation on tropical precipitation simulation in a climate model. The results showed that ocean data assimilation can effectively improve the sea surface temperature and ocean heat content in the upper layer of the ocean,the absolute mean error of annual mean SST in the area of 30°S~30°N were reduced by 60%. Sea level pressure and atmospheric circulation such as lower winds had been significantly improved. The atmospheric vertical motion turns to be more reasonable,which provide reliable dynamic conditions for precipitation simulation. Improvements of SST and atmospheric circulation would further influence the spatial distribution of the specific humidity and cloud fraction,giving more reasonable moisture conditions for precipitation simulation. Finally,the spatial distribution and intensity of zonal mean were significantly improved,the peak value of precipitation in the south of the equator were obviously reduced,and the absolute mean error of annual mean precipitation in the oceanic area of 30°S~30°N were reduced by 35%.
Using the Ensemble Adjustment Kalman Filter (EAKF),two kinds of oceanic satellite observations,namely sea surface temperature (SST) and sea level anomaly (SLA),had been assimilated into the ocean model component of the FIO-ESM (First Institute of Oceanography Earth System Model version 1.0). We analyzed the differences of the atmospheric circulation,specific humidity,cloud fraction,and precipitation in tropical between the assimilation and no assimilation experiment,to investigate the impacts of ocean data assimilation on tropical precipitation simulation in a climate model. The results showed that ocean data assimilation can effectively improve the sea surface temperature and ocean heat content in the upper layer of the ocean,the absolute mean error of annual mean SST in the area of 30°S~30°N were reduced by 60%. Sea level pressure and atmospheric circulation such as lower winds had been significantly improved. The atmospheric vertical motion turns to be more reasonable,which provide reliable dynamic conditions for precipitation simulation. Improvements of SST and atmospheric circulation would further influence the spatial distribution of the specific humidity and cloud fraction,giving more reasonable moisture conditions for precipitation simulation. Finally,the spatial distribution and intensity of zonal mean were significantly improved,the peak value of precipitation in the south of the equator were obviously reduced,and the absolute mean error of annual mean precipitation in the oceanic area of 30°S~30°N were reduced by 35%.
2015, 37(7): 54-66.
Abstract:
Since the satellite launched,the cross-calibration,validation and quality assessment for HY-2A satellite radar altimeter product have been ongoing. In this paper,we finish the verification work that HY-2A satellite altimeter 44th cycle IGDR product data was compared with Jason-2 IGDR through global distribution,two-dimensional histogram and the daily average methods. While the main environmental parameters and geophysical product data quality analysis showed that data quality are stable. In addition,the analysis of the SSH differences at crossovers between HY-2A ascending and descending tracks,the SSH differences at HY-2A and Jason-2 and sea Level Anomaly (SLA) along track have been done to evaluate performance of HY-2A satellite altimeter observation system,the results showed that sea surface height accuracy is about 7.48 cm,close to Jason-2. It can meet the needs of marine applications and scientific research.
Since the satellite launched,the cross-calibration,validation and quality assessment for HY-2A satellite radar altimeter product have been ongoing. In this paper,we finish the verification work that HY-2A satellite altimeter 44th cycle IGDR product data was compared with Jason-2 IGDR through global distribution,two-dimensional histogram and the daily average methods. While the main environmental parameters and geophysical product data quality analysis showed that data quality are stable. In addition,the analysis of the SSH differences at crossovers between HY-2A ascending and descending tracks,the SSH differences at HY-2A and Jason-2 and sea Level Anomaly (SLA) along track have been done to evaluate performance of HY-2A satellite altimeter observation system,the results showed that sea surface height accuracy is about 7.48 cm,close to Jason-2. It can meet the needs of marine applications and scientific research.
2015, 37(7): 67-77.
Abstract:
Colored dissolved organic matters(CDOM) directly affect the optical characteristics of sea water. As one of the fundamental parameters of inverse modeling the water organic pollution content water color remote sensing,the concentration of CDOM in the water is usually indexed by the absorption coefficeient at 440 nm wavelength,ag(440). Therefore,in order to obtain the spatial variability of the CDOM concentration in the relevant areas and to extract other water environmental paramenters,it is essential to establish a remote sensing inverse model of ag(440). Applying the in-site measured apparent and inherent optical properties of Zhujiang River Estuary of southern China in November 2013 and February 2014,respectively,we established a remote sensing inverse model of ag(440) based on the HJ-1/CCD satellite. The model is then applied to Zhujiang River Estuary to obtain the spatial distribution of CDOM concentration under the clear sky between January 2012 and June 2014. The results that,(1) the in-situ measured ag(440) in Zhujiang River Estuary varied between 0.1 and 0.3 m-1,the value is obviously larger in the areas with high influence of land and river runoff than those with low influence of land and river runoff. It also shows some regular variation with differene sections; (2) the validation of the model by the in-situ data givers a relative error of 9%,indicating a high accuracy of the inverse model; (3) the CDOM spatial distribution data from the inverse model are in good agreement with the observation,in the whole Zhujiang River Estuary and the adjacent areas,ag(440) varies between 0.07 and 0.31 m-1,and the value is higher in the western part of the estuary than the eastern part.
Colored dissolved organic matters(CDOM) directly affect the optical characteristics of sea water. As one of the fundamental parameters of inverse modeling the water organic pollution content water color remote sensing,the concentration of CDOM in the water is usually indexed by the absorption coefficeient at 440 nm wavelength,ag(440). Therefore,in order to obtain the spatial variability of the CDOM concentration in the relevant areas and to extract other water environmental paramenters,it is essential to establish a remote sensing inverse model of ag(440). Applying the in-site measured apparent and inherent optical properties of Zhujiang River Estuary of southern China in November 2013 and February 2014,respectively,we established a remote sensing inverse model of ag(440) based on the HJ-1/CCD satellite. The model is then applied to Zhujiang River Estuary to obtain the spatial distribution of CDOM concentration under the clear sky between January 2012 and June 2014. The results that,(1) the in-situ measured ag(440) in Zhujiang River Estuary varied between 0.1 and 0.3 m-1,the value is obviously larger in the areas with high influence of land and river runoff than those with low influence of land and river runoff. It also shows some regular variation with differene sections; (2) the validation of the model by the in-situ data givers a relative error of 9%,indicating a high accuracy of the inverse model; (3) the CDOM spatial distribution data from the inverse model are in good agreement with the observation,in the whole Zhujiang River Estuary and the adjacent areas,ag(440) varies between 0.07 and 0.31 m-1,and the value is higher in the western part of the estuary than the eastern part.
2015, 37(7): 78-84.
Abstract:
Argo data from 2010 to 2013 was used to analyze the convergence zone's features in the east of Luzon strait(19°~23°N,123°~127°E). The results as shows: (1)The acoustic velocity near ocean surface in seasons were ranked from large to small: summer,autumn,spring and winter. The maximum acoustic velocity is 1 543.5 m/s in summer while the minimum is 1 533.4 m/s in winter. The mixed layer depth in seasons were ordered from large to small as followed: winter,autumn,spring and summer. (2)The WOA13 climatological data was used to prolong the sound velocity profiles to seafloor. Analysis the features of sound channel in seasons.The depth and sound velocity of sound channel axis were stabilized. The depth was in 1 000 to 1 040 m,the sound velocity of sound channel axis is 1 482 m/s. The length of sound channel more than 4 500 m in all four seasons,it was beneficial to formed convergence zone. (3)The study area formed convergence zone surely,the probability which is more than 50% accounted for 70.6%. The occurrence probability of convergence zone was seasonal variation significantly,spring and winter is more likely to formed,summer is least. (4)The RAMGeo acoustic forecast model was used to simulate the four seasons' acoustic transmission loss in the east of Luzon strait,obtained the seasonal variation of the convergence zone in the study area. While the source depth is 100 m,the receiver depth is 10 m: the first convergence zone,the distance from sound source is 61 to 64 km,the nearest distance is in summer,while the farther is in spring and winter. The convergence-wide,the maximum is 10 km in summer,while the minimum is 4.6 km in spring. The distribution of convergence-gains is opposite with convergence-wide in seasons,the strongest is 14.6 dB in spring,while the least is 8.5 dB in summer.
Argo data from 2010 to 2013 was used to analyze the convergence zone's features in the east of Luzon strait(19°~23°N,123°~127°E). The results as shows: (1)The acoustic velocity near ocean surface in seasons were ranked from large to small: summer,autumn,spring and winter. The maximum acoustic velocity is 1 543.5 m/s in summer while the minimum is 1 533.4 m/s in winter. The mixed layer depth in seasons were ordered from large to small as followed: winter,autumn,spring and summer. (2)The WOA13 climatological data was used to prolong the sound velocity profiles to seafloor. Analysis the features of sound channel in seasons.The depth and sound velocity of sound channel axis were stabilized. The depth was in 1 000 to 1 040 m,the sound velocity of sound channel axis is 1 482 m/s. The length of sound channel more than 4 500 m in all four seasons,it was beneficial to formed convergence zone. (3)The study area formed convergence zone surely,the probability which is more than 50% accounted for 70.6%. The occurrence probability of convergence zone was seasonal variation significantly,spring and winter is more likely to formed,summer is least. (4)The RAMGeo acoustic forecast model was used to simulate the four seasons' acoustic transmission loss in the east of Luzon strait,obtained the seasonal variation of the convergence zone in the study area. While the source depth is 100 m,the receiver depth is 10 m: the first convergence zone,the distance from sound source is 61 to 64 km,the nearest distance is in summer,while the farther is in spring and winter. The convergence-wide,the maximum is 10 km in summer,while the minimum is 4.6 km in spring. The distribution of convergence-gains is opposite with convergence-wide in seasons,the strongest is 14.6 dB in spring,while the least is 8.5 dB in summer.
2015, 37(7): 85-96.
Abstract:
A gravity core M04 was taken from the Chukchi Sea Basin during the fifth Chinese National Arctic Research Expedition in 2012. All samples were analyzed for grain size,ice-raft detritus,clay mineral,XRF scanning and sediment color features. The stratigraphic framework of core M04 since Marine Isotope Stage 4 was established by synthesizing results of IRD,color cycles,clay proxies (kaolinite to illite and kaolinite to chlorite ratios),AMS14C ages,as done previously for other cores. It is clearly distinguished between sediments deposited during glacial and interglacial with the grain size and clay mineral composition of sediments. During glacial,the grain size distribution is bimodal components of the sediment through the current transport and sea ice transport process,with high content of illite and low content of kaolinite. In contrast,during interglacial,the grain size distribution is trimodal components of the sediment through the current transport and sea ice and iceberg transport process,with content of illite reducsing and content of kaolinite increasing. Clay-mineral association in core M04 and the adjacent marginal continental shelf areas are compared to identify source areas and transport pathways of terrigenous material in the Chukchi Sea Basin during the Late Pleistocene. Based on the above study,it is indicated that sedimentary environment has been significantly changed from the late Pleistocene.During the interglacial stage,terrestrial sources input into the study area from the Beaufort Sea driven by Beaufort Gyre,but during the glacial stage,fine particulate terrigenous input from the East Siberian Sea driven by the opposite direction circulation.
A gravity core M04 was taken from the Chukchi Sea Basin during the fifth Chinese National Arctic Research Expedition in 2012. All samples were analyzed for grain size,ice-raft detritus,clay mineral,XRF scanning and sediment color features. The stratigraphic framework of core M04 since Marine Isotope Stage 4 was established by synthesizing results of IRD,color cycles,clay proxies (kaolinite to illite and kaolinite to chlorite ratios),AMS14C ages,as done previously for other cores. It is clearly distinguished between sediments deposited during glacial and interglacial with the grain size and clay mineral composition of sediments. During glacial,the grain size distribution is bimodal components of the sediment through the current transport and sea ice transport process,with high content of illite and low content of kaolinite. In contrast,during interglacial,the grain size distribution is trimodal components of the sediment through the current transport and sea ice and iceberg transport process,with content of illite reducsing and content of kaolinite increasing. Clay-mineral association in core M04 and the adjacent marginal continental shelf areas are compared to identify source areas and transport pathways of terrigenous material in the Chukchi Sea Basin during the Late Pleistocene. Based on the above study,it is indicated that sedimentary environment has been significantly changed from the late Pleistocene.During the interglacial stage,terrestrial sources input into the study area from the Beaufort Sea driven by Beaufort Gyre,but during the glacial stage,fine particulate terrigenous input from the East Siberian Sea driven by the opposite direction circulation.
2015, 37(7): 97-107.
Abstract:
Sand wave is a widely occurring submarine bedform which exists on the sea floor of shallow seas due to the complex interaction between waves,tides and sediments. Knowledge of sand wave characteristics and behavior has scientific import and engineering application value. Crest lines and trough lines are basic topographic characteristics of sand wave,and the basis to describe sand wave variation. In this paper,we present a new method of automatic recognition of sand wave topographic features based on composite digital depth model (DDM),called optimally-directional profiling method. We built an optimal direction map from DDM,and use the optimal direction to profile DDM and involve matrix calculus,by verifying extrema points to extract the topographic features. Taking composite sand waves in Taiwan Bank as an example,the comparison experiment result indicated that,the method is capable of extracting crest lines and trough lines of sand waves automatically and accurately based on multi-resolution DDM. With no requirement for setting any thresholds,the automatic degree of extracting topographic features is further increased. The method possessed important practical application value.
Sand wave is a widely occurring submarine bedform which exists on the sea floor of shallow seas due to the complex interaction between waves,tides and sediments. Knowledge of sand wave characteristics and behavior has scientific import and engineering application value. Crest lines and trough lines are basic topographic characteristics of sand wave,and the basis to describe sand wave variation. In this paper,we present a new method of automatic recognition of sand wave topographic features based on composite digital depth model (DDM),called optimally-directional profiling method. We built an optimal direction map from DDM,and use the optimal direction to profile DDM and involve matrix calculus,by verifying extrema points to extract the topographic features. Taking composite sand waves in Taiwan Bank as an example,the comparison experiment result indicated that,the method is capable of extracting crest lines and trough lines of sand waves automatically and accurately based on multi-resolution DDM. With no requirement for setting any thresholds,the automatic degree of extracting topographic features is further increased. The method possessed important practical application value.
2015, 37(7): 108-122.
Abstract:
Ocean waves simulation during 2001 to 2010 was constructed to explore the ocean waves energy in Shandong offshore by using the third-generation wave model SWAN. The validation results show the model is accurate and robust comparing with the observations. The average wave energy flux densities in Shandong offshore are almost below 2 000 W/m,which are lower than the European countries and the southern coast of China. 12 points around Shandong offshore were analyzed from variations of wave energy flux density and other objective wave energy related factors,which show that the wave energy flux density appears an obvious rising trend due to climate change. From the comprehensive view,three areas are recommended as the priority area for the development of ocean wave energy,which are the eastern offshore of Shandong,the central area of the Bohai and the outer ocean near Penglai islands. In Chengshan eastern sea,the wave energy resource is abundant. The wave energy flux density in the winter is up to 5 000 W/m. For this,the development and utilization of small and medium-sized power supply equipment or facilities are in line with reality.
Ocean waves simulation during 2001 to 2010 was constructed to explore the ocean waves energy in Shandong offshore by using the third-generation wave model SWAN. The validation results show the model is accurate and robust comparing with the observations. The average wave energy flux densities in Shandong offshore are almost below 2 000 W/m,which are lower than the European countries and the southern coast of China. 12 points around Shandong offshore were analyzed from variations of wave energy flux density and other objective wave energy related factors,which show that the wave energy flux density appears an obvious rising trend due to climate change. From the comprehensive view,three areas are recommended as the priority area for the development of ocean wave energy,which are the eastern offshore of Shandong,the central area of the Bohai and the outer ocean near Penglai islands. In Chengshan eastern sea,the wave energy resource is abundant. The wave energy flux density in the winter is up to 5 000 W/m. For this,the development and utilization of small and medium-sized power supply equipment or facilities are in line with reality.
2015, 37(7): 123-131.
Abstract:
MODIS images are valuable data source generated from operational satellite remote sensing for monitoring Enteromorpha in the Yellow Sea. However,there are large errors inenteromorpha coverage derived on base of NDVI Threshold Method,because of mixed pixels in the coarse resolution(250 m) MODIS images. To solve the problem,this paper,using the near real-time HJ-1 CCD images as reference,the "NDVI-abundance" decomposition of mixed pixel model was established. The developed model can significantly improve the extracted Enteromorpha information. As the method presented here can extract more accurate information,it is speculated to play a significant role in copying with Enteromorpha disasters.
MODIS images are valuable data source generated from operational satellite remote sensing for monitoring Enteromorpha in the Yellow Sea. However,there are large errors inenteromorpha coverage derived on base of NDVI Threshold Method,because of mixed pixels in the coarse resolution(250 m) MODIS images. To solve the problem,this paper,using the near real-time HJ-1 CCD images as reference,the "NDVI-abundance" decomposition of mixed pixel model was established. The developed model can significantly improve the extracted Enteromorpha information. As the method presented here can extract more accurate information,it is speculated to play a significant role in copying with Enteromorpha disasters.
2015, 37(7): 132-141.
Abstract:
Calcareous nannofossils biostratigraphy was studied on a sample of Co-rich ferromanganese crust,CM3D06,from the Magellanseamounts in the Western Pacific. The occurrences of classic calcareous nannofossils,which can typically represent the eras from the late Cretaceous to the Pleistocene,indicate that the crust has started forming in the Late Cretaceous. A suit of molecular fossils,including n-alkane,isoprenoid hydrocarbon and sterane,were detected in the Co-rich ferromanganese crust. Features of the molecular characteristics index,MH,ΣC23-/C24+、CPI 、Pr/Ph、Pr/nC17、Ph/nC18和nC31/nC17 suggest the organic source in the crust mainly from marine phytoplankton、zooplankton and benthic non-photosynthetic fungus. The proportion patterns of C29、C28 and C27 of the sterol component show the rapid evolution of the organism population. The relationship between the growing of the crust and the changes in the oceanic environment was also addressed through the organic carbon isotope and Pr/Ph analyses on each layer of the crust.
Calcareous nannofossils biostratigraphy was studied on a sample of Co-rich ferromanganese crust,CM3D06,from the Magellanseamounts in the Western Pacific. The occurrences of classic calcareous nannofossils,which can typically represent the eras from the late Cretaceous to the Pleistocene,indicate that the crust has started forming in the Late Cretaceous. A suit of molecular fossils,including n-alkane,isoprenoid hydrocarbon and sterane,were detected in the Co-rich ferromanganese crust. Features of the molecular characteristics index,MH,ΣC23-/C24+、CPI 、Pr/Ph、Pr/nC17、Ph/nC18和nC31/nC17 suggest the organic source in the crust mainly from marine phytoplankton、zooplankton and benthic non-photosynthetic fungus. The proportion patterns of C29、C28 and C27 of the sterol component show the rapid evolution of the organism population. The relationship between the growing of the crust and the changes in the oceanic environment was also addressed through the organic carbon isotope and Pr/Ph analyses on each layer of the crust.
2015, 37(7): 142-152.
Abstract:
Since the 1950s,coastal erosion has always occurred in Guangdong province. Based on comprehensive survey,this paper describes the status,classifies the intensity and discusses the intensity-distribution law of Guangdong coastal erosion; summarize the features and differences of different types of coastal erosion; moreover,on analysis of the affecting factors,coastal erosion is regarded as the coefficient result of the natural and human activities,with the latter as the main factor that aggravates coastal erosion. This study is beneficial to realize the disaster mitigation and prevention in Guangdong coastal zone,establishing a fruitful basis for future disaster research.
Since the 1950s,coastal erosion has always occurred in Guangdong province. Based on comprehensive survey,this paper describes the status,classifies the intensity and discusses the intensity-distribution law of Guangdong coastal erosion; summarize the features and differences of different types of coastal erosion; moreover,on analysis of the affecting factors,coastal erosion is regarded as the coefficient result of the natural and human activities,with the latter as the main factor that aggravates coastal erosion. This study is beneficial to realize the disaster mitigation and prevention in Guangdong coastal zone,establishing a fruitful basis for future disaster research.
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