2013 Vol. 35, No. 4
Display Method:
2013, 35(4): 1-10.
doi: 10.3969/j.issn.0253-4193.2013.04.001
Abstract:
The recent advances in marine zooplankton research is reviews, which includes research areas of marine zooplankton community structure and biodiversity and zooplankton's responses to global climate change. Marine zooplankton is rich in species numbers, abundant and widely distributed, and they play a vital role in marine ecosystems. In the marine food webs, zooplankton controls primary production by grazing on phytoplankton. At the same time, they are the prey of animals of higher trophic levels, such as fish, shrimp, whales and seabirds, acting as the role of secondary producers. The community structure, population dynamics and species diversity of zooplankton influence the amount of fish and other marine animal resources. Thus, zooplankton is the key link in the marine food webs, and the biological and ecological processes of zooplankton drive the ecosystem dynamics in global oceans. Many international research programs have focused on the biological diversity, inter-annual variability and long-term trend of the plankton communities, and related them to global climate change. This paper summarized the recent advances in zooplankton research in the following 6 major areas: (1) zooplankton habitats, population distributions and proliferation dynamics; (2) community structure and diversity of zooplankton; (3) experimental ecology and controlled in situ ecological study of zooplankton; (4) zooplankton's responses to global climate change; (5) zooplankton ecology in extreme habitats such as deep-sea, polar and low-oxygen areas; (6) new technologies and methods for zooplankton research．
The recent advances in marine zooplankton research is reviews, which includes research areas of marine zooplankton community structure and biodiversity and zooplankton's responses to global climate change. Marine zooplankton is rich in species numbers, abundant and widely distributed, and they play a vital role in marine ecosystems. In the marine food webs, zooplankton controls primary production by grazing on phytoplankton. At the same time, they are the prey of animals of higher trophic levels, such as fish, shrimp, whales and seabirds, acting as the role of secondary producers. The community structure, population dynamics and species diversity of zooplankton influence the amount of fish and other marine animal resources. Thus, zooplankton is the key link in the marine food webs, and the biological and ecological processes of zooplankton drive the ecosystem dynamics in global oceans. Many international research programs have focused on the biological diversity, inter-annual variability and long-term trend of the plankton communities, and related them to global climate change. This paper summarized the recent advances in zooplankton research in the following 6 major areas: (1) zooplankton habitats, population distributions and proliferation dynamics; (2) community structure and diversity of zooplankton; (3) experimental ecology and controlled in situ ecological study of zooplankton; (4) zooplankton's responses to global climate change; (5) zooplankton ecology in extreme habitats such as deep-sea, polar and low-oxygen areas; (6) new technologies and methods for zooplankton research．
2013, 35(4): 11-18.
doi: 10.3969/j.issn.0253-4193.2013.04.002
Abstract:
In this paper, the hydrographic survey data in coastal waters of Guangdong, Hainan, and Guangxi during the summer of 2006, combined with QuikSCAT wind data were used to document spatial characteristics of upwelling, and to explore roles of the wind and wind stress curl on the upwelling, and responses of temperature, currents, sea level to the upwelling. The results show that the coastal upwelling regions in eastern Hainan and western Guangdong are not separated but merged together below 10 m layer. The coastal upwelling in eastern Hainan is mainly driven by the southwest monsoon during summer, and the wind stress curl also impacts the process of upwelling. The coastal upwelling in western Guangdong is mainly caused by the local wind stress curl. The intensity of upwelling in eastern Hainan coast was stronger than that in western Guangdong coast. In eastern Hainan coast, the water in upper layer (<18 m) moved primarily offshore, while the water in lower layer moved dominantly onshore, with a stronger flow in upper layer. The upwelling phenomenon in eastern Hainan is intermittent, and modulated by the strength of alongshore wind. The strength of coastal upwelling in eastern Hainan was closely correlated to local sea surface height, with variations of former lag that of later in 1-2 days.
In this paper, the hydrographic survey data in coastal waters of Guangdong, Hainan, and Guangxi during the summer of 2006, combined with QuikSCAT wind data were used to document spatial characteristics of upwelling, and to explore roles of the wind and wind stress curl on the upwelling, and responses of temperature, currents, sea level to the upwelling. The results show that the coastal upwelling regions in eastern Hainan and western Guangdong are not separated but merged together below 10 m layer. The coastal upwelling in eastern Hainan is mainly driven by the southwest monsoon during summer, and the wind stress curl also impacts the process of upwelling. The coastal upwelling in western Guangdong is mainly caused by the local wind stress curl. The intensity of upwelling in eastern Hainan coast was stronger than that in western Guangdong coast. In eastern Hainan coast, the water in upper layer (<18 m) moved primarily offshore, while the water in lower layer moved dominantly onshore, with a stronger flow in upper layer. The upwelling phenomenon in eastern Hainan is intermittent, and modulated by the strength of alongshore wind. The strength of coastal upwelling in eastern Hainan was closely correlated to local sea surface height, with variations of former lag that of later in 1-2 days.
2013, 35(4): 19-28.
doi: 10.3969/j.issn.0253-4193.2013.04.003
Abstract:
A three-dimensional hydrodynamic model for Changjiang Estuary and the adjacent sea was developed within the framework of Environmental Fluid Dynamics Code (EFDC). The effect of vertical resolution on the simulation of M2 tide was analyzed. The direction of M2 tide propagation was simulated correctly. The M2 tide propagated from southeast to northwest in open sea, then it propagated inland along coastline in Changjiang River and Hangzhou Bay. The bottom stress and turbulence varying with vertical resolution determined the energy propagated into Changjiang River and Hangzhou Bay. This made the amplitude of M2 tide decrease with increasing vertical resolution in Changjiang River. But in Hangzhou Bay, the amplitude of M2 tide increased with increasing vertical resolution at first, then decreased with increasing vertical resolution. The computation of bottom stress was based on the mixing length theory and the boundary layer was assumed to be a constant fluxes layer. The bottom layer should be thin enough so that the higher velocity of the upper water, which resulted in higher bottom stress, was of little importance in bottom layer. The intensity of vertical turbulence increased with increasing vertical resolution. This transmitted more high velocity of upper water into bottom layer and resulted in higher bottom stress again. Finally, the more consumption of energy caused by higher bottom stress made the amplitude of M2 tide become smaller．
A three-dimensional hydrodynamic model for Changjiang Estuary and the adjacent sea was developed within the framework of Environmental Fluid Dynamics Code (EFDC). The effect of vertical resolution on the simulation of M2 tide was analyzed. The direction of M2 tide propagation was simulated correctly. The M2 tide propagated from southeast to northwest in open sea, then it propagated inland along coastline in Changjiang River and Hangzhou Bay. The bottom stress and turbulence varying with vertical resolution determined the energy propagated into Changjiang River and Hangzhou Bay. This made the amplitude of M2 tide decrease with increasing vertical resolution in Changjiang River. But in Hangzhou Bay, the amplitude of M2 tide increased with increasing vertical resolution at first, then decreased with increasing vertical resolution. The computation of bottom stress was based on the mixing length theory and the boundary layer was assumed to be a constant fluxes layer. The bottom layer should be thin enough so that the higher velocity of the upper water, which resulted in higher bottom stress, was of little importance in bottom layer. The intensity of vertical turbulence increased with increasing vertical resolution. This transmitted more high velocity of upper water into bottom layer and resulted in higher bottom stress again. Finally, the more consumption of energy caused by higher bottom stress made the amplitude of M2 tide become smaller．
2013, 35(4): 29-35.
doi: 10.3969/j.issn.0253-4193.2013.04.004
Abstract:
Based on the 3D numerical model with high resolution grid, the response time of saltwater intrusion in the Changjiang Estuary to the change of river discharge at Datong in different tidal pattern is studied. The calculated domain of the model includes the lower reaches of the Changjiang River from Datong to the Changjiang Estuary and its adjacent sea. The results show that the time response of saltwater intrusion to the increasing river discharge at Datong in different tidal pattern is 4.0 to 6.2 days, and is obvious longer in neap tide than the one in other tidal pattern. The response time of saltwater intrusion to the river discharge change in dry season was solved in this paper, which can be as a scientific reference when the river discharge should be used in the studies of hydrology, sediment and environment in the Changjiang Estuary.
Based on the 3D numerical model with high resolution grid, the response time of saltwater intrusion in the Changjiang Estuary to the change of river discharge at Datong in different tidal pattern is studied. The calculated domain of the model includes the lower reaches of the Changjiang River from Datong to the Changjiang Estuary and its adjacent sea. The results show that the time response of saltwater intrusion to the increasing river discharge at Datong in different tidal pattern is 4.0 to 6.2 days, and is obvious longer in neap tide than the one in other tidal pattern. The response time of saltwater intrusion to the river discharge change in dry season was solved in this paper, which can be as a scientific reference when the river discharge should be used in the studies of hydrology, sediment and environment in the Changjiang Estuary.
2013, 35(4): 36-46.
doi: 10.3969/j.issn.0253-4193.2013.04.005
Abstract:
Variation of pack ice extent (PIE) in summer Arctic is important for understanding the sea-ice change in Arctic Ocean. As the ice concentration smoothly decreases from pack ice to marginal ice zone(MIZ), there is no definite boundary between them. Therefore a threshold of ice concentration, C0, is required to define a margin of the pack ice in order to study the spatiotemporal variation of pack ice coverage. Two characteristics of ice concentration variation were obtained using 6.25 km resolution data of AMSR-E. The pack ice areas decrease with higher thresholds of ice concentration, whereas the decreasing rate with ice concentration is not uniform. A value of ice concentration could be chosen as a threshold at which the decreasing rate shifts from faster to slower. Meanwhile, the differences of ice concentration with neighboring grids will have a biggest statistical change nearby the margin. The suggested thresholds by the two characteristics mentioned above are all 89%, indicating a well defined threshold with clear physical significance. Based on the threshold of ice concentration, an erosion algorithm is used to eliminate the MIZ and a connected domain algorithm is used to remove the small ice pieces out of the pack ice. The larger PIE appeared during 2002-2006 with little annual variation. Since 2007, PIE decreased obviously. The minimum PIE was renewed in 2010 and 2011, especially the PIE of 2011 is only 64% of 2006. The variation of PIE is quite different from the ice-coverage extent (PIE plus MIZ), being an relative independent parameter in reflecting the sea ice variation in the area with high ice concentration. Sea-ice melting and variability of MIZ are two main factors influence the PIE. MIZ could extend or shrink by dynamic factors, which will induce some ice blocks moving from or into pack ice, leading to an associated transition between PIE and MIZ. This paper provides a new insight about sea ice variation in the Arctic, and the decrease of PIE indicates the ongoing reduce of pack ice in central Arctic Ocean．
Variation of pack ice extent (PIE) in summer Arctic is important for understanding the sea-ice change in Arctic Ocean. As the ice concentration smoothly decreases from pack ice to marginal ice zone(MIZ), there is no definite boundary between them. Therefore a threshold of ice concentration, C0, is required to define a margin of the pack ice in order to study the spatiotemporal variation of pack ice coverage. Two characteristics of ice concentration variation were obtained using 6.25 km resolution data of AMSR-E. The pack ice areas decrease with higher thresholds of ice concentration, whereas the decreasing rate with ice concentration is not uniform. A value of ice concentration could be chosen as a threshold at which the decreasing rate shifts from faster to slower. Meanwhile, the differences of ice concentration with neighboring grids will have a biggest statistical change nearby the margin. The suggested thresholds by the two characteristics mentioned above are all 89%, indicating a well defined threshold with clear physical significance. Based on the threshold of ice concentration, an erosion algorithm is used to eliminate the MIZ and a connected domain algorithm is used to remove the small ice pieces out of the pack ice. The larger PIE appeared during 2002-2006 with little annual variation. Since 2007, PIE decreased obviously. The minimum PIE was renewed in 2010 and 2011, especially the PIE of 2011 is only 64% of 2006. The variation of PIE is quite different from the ice-coverage extent (PIE plus MIZ), being an relative independent parameter in reflecting the sea ice variation in the area with high ice concentration. Sea-ice melting and variability of MIZ are two main factors influence the PIE. MIZ could extend or shrink by dynamic factors, which will induce some ice blocks moving from or into pack ice, leading to an associated transition between PIE and MIZ. This paper provides a new insight about sea ice variation in the Arctic, and the decrease of PIE indicates the ongoing reduce of pack ice in central Arctic Ocean．
2013, 35(4): 47-51.
doi: 10.3969/j.issn.0253-4193.2013.04.006
Abstract:
The temperature anomalies lag relationship between whole south Indian Ocean and the upper welling region of the southwest tropical Indian Ocean is investigated using the Simple Ocean Data Assimilation (SODA) oceanic reanalyses. The results indicate that the signal of temperature anomalies propagates from high latitude to low latitude along thermocline in the southeast Indian Ocean. It is found that the atmospheric perturbation drive the signal in the ocean located around 65°S, 105°E at the beginning, then it reaches to southeast Indian Ocean after about 10 a. The possible reason is also discussed in this study．
The temperature anomalies lag relationship between whole south Indian Ocean and the upper welling region of the southwest tropical Indian Ocean is investigated using the Simple Ocean Data Assimilation (SODA) oceanic reanalyses. The results indicate that the signal of temperature anomalies propagates from high latitude to low latitude along thermocline in the southeast Indian Ocean. It is found that the atmospheric perturbation drive the signal in the ocean located around 65°S, 105°E at the beginning, then it reaches to southeast Indian Ocean after about 10 a. The possible reason is also discussed in this study．
2013, 35(4): 52-63.
doi: 10.3969/j.issn.0253-4193.2013.04.007
Abstract:
Gas transfer velocity of CO2 on the air-sea interface over North Pacific has been constructed using four bulk formulas, and the seasonal variation of gas transfer velocity and CO2 flux are studied. Compared with wind speed dependent parameterizations, the wave-derived formulas result in different seasonal pattern of transfer velocity and CO2 flux. In tropical and sub-tropical zone (0°-30°N), the wave-dependent formulas show weaker gas transfer velocity and less air to sea CO2 flux. In the northern area (30°-50°N), wave-dependent formulas enhance gas transfer velocity and result in larger CO2 flux from air to sea. Furthermore, climatological monthly mean gas transfer velocity and the CO2 flux in Kuroshio Extension are calculated. The results reveal that gas transfer velocity and CO2 flux reach maximum in winter and spring respectively. The differences among four bulk formulas on the mean gas transfer velocity and CO2 flux in Kuroshio Extrension are not significant, but the wave parameterization causes stronger seasonal variance．
Gas transfer velocity of CO2 on the air-sea interface over North Pacific has been constructed using four bulk formulas, and the seasonal variation of gas transfer velocity and CO2 flux are studied. Compared with wind speed dependent parameterizations, the wave-derived formulas result in different seasonal pattern of transfer velocity and CO2 flux. In tropical and sub-tropical zone (0°-30°N), the wave-dependent formulas show weaker gas transfer velocity and less air to sea CO2 flux. In the northern area (30°-50°N), wave-dependent formulas enhance gas transfer velocity and result in larger CO2 flux from air to sea. Furthermore, climatological monthly mean gas transfer velocity and the CO2 flux in Kuroshio Extension are calculated. The results reveal that gas transfer velocity and CO2 flux reach maximum in winter and spring respectively. The differences among four bulk formulas on the mean gas transfer velocity and CO2 flux in Kuroshio Extrension are not significant, but the wave parameterization causes stronger seasonal variance．
2013, 35(4): 64-71.
doi: 10.3969/j.issn.0253-4193.2013.04.008
Abstract:
The reliability of air-sea CO2 fluxes estimation model parameters is an important factor in determining the reliability of the model and also determines the reliability of the model estimation results, so it is important to carry out the sea-air CO2 fluxes estimation model error propagation law and sensitivity analysis for controlling the endmember factors of the model parameters, improving the model prediction accuracy and reducing the uncertainty. Since there are many parameters in the model, and various parameters influence each other, it is difficult to analyze error propagation process and sensitivity analysis. In this paper, based on the detailed analysis of air-sea CO2 fluxes estimation model establishment process and the classic computation model of the air-sea CO2 fluxes 2 partial pressure difference, taking the in situ data fluxes model establishment as an example, in term of the parameters in the model, assuming the normal distribution of the parameter error, the error propagation law of each parameter in the model was analyzed using the Monte Carlo technique, and the single-factor perturbation test method was used for the air-sea CO2 fluxes estimation model parameters sensitivity analysis. It was shown from the simulation and analytical results: CO2 flux measurement model error propagation law meet various forms, such as the normal distribution and exponential distribution; gas exchange coefficient is sensitive to the flux calculation results, and the wind speed and sea surface temperature accuracy are the critical parameters to be concerned and controlled in the process of the flux estimation.
The reliability of air-sea CO2 fluxes estimation model parameters is an important factor in determining the reliability of the model and also determines the reliability of the model estimation results, so it is important to carry out the sea-air CO2 fluxes estimation model error propagation law and sensitivity analysis for controlling the endmember factors of the model parameters, improving the model prediction accuracy and reducing the uncertainty. Since there are many parameters in the model, and various parameters influence each other, it is difficult to analyze error propagation process and sensitivity analysis. In this paper, based on the detailed analysis of air-sea CO2 fluxes estimation model establishment process and the classic computation model of the air-sea CO2 fluxes 2 partial pressure difference, taking the in situ data fluxes model establishment as an example, in term of the parameters in the model, assuming the normal distribution of the parameter error, the error propagation law of each parameter in the model was analyzed using the Monte Carlo technique, and the single-factor perturbation test method was used for the air-sea CO2 fluxes estimation model parameters sensitivity analysis. It was shown from the simulation and analytical results: CO2 flux measurement model error propagation law meet various forms, such as the normal distribution and exponential distribution; gas exchange coefficient is sensitive to the flux calculation results, and the wind speed and sea surface temperature accuracy are the critical parameters to be concerned and controlled in the process of the flux estimation.
2013, 35(4): 72-79.
doi: 10.3969/j.issn.0253-4193.2013.04.009
Abstract:
Based on CCMP data, ECMWF wave data and the latest CO2 data, we made an estimation of air-sea CO2 flux by using 2 bi-parameter gas transfer velocity formulas and 4 gas transfer velocity formulas parameterized by wind speed. The former result is 30% larger than the latter one. On the whole, bi-parameter formulas strengthen both sink and source of CO2 in the ocean. Extended research on the influence of average time-scale on estimation of air-sea CO2 flux was made. Result of scaler averaging method is much more stable than that of vector averaging method.Average global sea wind speed was enlarging during 1988-2009, while the uptake of CO2 didn't change much.In the past 20 years, the uptake ability of global ocean declined．
Based on CCMP data, ECMWF wave data and the latest CO2 data, we made an estimation of air-sea CO2 flux by using 2 bi-parameter gas transfer velocity formulas and 4 gas transfer velocity formulas parameterized by wind speed. The former result is 30% larger than the latter one. On the whole, bi-parameter formulas strengthen both sink and source of CO2 in the ocean. Extended research on the influence of average time-scale on estimation of air-sea CO2 flux was made. Result of scaler averaging method is much more stable than that of vector averaging method.Average global sea wind speed was enlarging during 1988-2009, while the uptake of CO2 didn't change much.In the past 20 years, the uptake ability of global ocean declined．
2013, 35(4): 80-87.
doi: 10.3969/j.issn.0253-4193.2013.04.010
Abstract:
Along with the appearance of a great deal of high-resolution quad-polarization synthetic aperture radar (SAR) images, the traditional classification methods lead to worse results with lower classification precision due to the speckle. Therefore, the object-based method based on the context has been used to classify the types of sea ice of RADARSAT-2 SAR image in the Liaodong Gulf. The classification result is compared with that of professional classification and Wishard supervised classification based on H-α decomposition, It is showed that this method can eliminate the speckle with better visual effect and higher classification precision．
Along with the appearance of a great deal of high-resolution quad-polarization synthetic aperture radar (SAR) images, the traditional classification methods lead to worse results with lower classification precision due to the speckle. Therefore, the object-based method based on the context has been used to classify the types of sea ice of RADARSAT-2 SAR image in the Liaodong Gulf. The classification result is compared with that of professional classification and Wishard supervised classification based on H-α decomposition, It is showed that this method can eliminate the speckle with better visual effect and higher classification precision．
2013, 35(4): 88-97.
doi: 10.3969/j.issn.0253-4193.2013.04.011
Abstract:
Sea surface temperature (SST) products are important data sources for global ocean atmosphere system studies, and of great importance for research and applications in marine related fields. Six SST analysis products (AVHRR-only, AMSR+AVHRR, NCODA, RSS, RTG-HR and OSTIA) are compared and evaluated for January and July 2007 near the Agulhas Return Current (ARC) in the south Indian Ocean and the circumpolar circulation regions.The characteristics of the six products are compared in terms of monthly averaged SST analysis, SST gradient, statistical parameter analysis and wavenumber spectra analysis. These results suggest that the overall trend of the variability changes of the SST products is consistent. However, the RTG-HR analysis is much smoother than the other analyses, oceanic front from the OSTIA analysis is the weakest, the RSS is much noisier, and the NCODA analysis exhibits apparent bias. With sufficient satellite infrared observations under cloud-free conditions, it is found that microwave AMSR observations cannot provide more additional SST information, otherwise it will reduce the spatial variability of the SST products.
Sea surface temperature (SST) products are important data sources for global ocean atmosphere system studies, and of great importance for research and applications in marine related fields. Six SST analysis products (AVHRR-only, AMSR+AVHRR, NCODA, RSS, RTG-HR and OSTIA) are compared and evaluated for January and July 2007 near the Agulhas Return Current (ARC) in the south Indian Ocean and the circumpolar circulation regions.The characteristics of the six products are compared in terms of monthly averaged SST analysis, SST gradient, statistical parameter analysis and wavenumber spectra analysis. These results suggest that the overall trend of the variability changes of the SST products is consistent. However, the RTG-HR analysis is much smoother than the other analyses, oceanic front from the OSTIA analysis is the weakest, the RSS is much noisier, and the NCODA analysis exhibits apparent bias. With sufficient satellite infrared observations under cloud-free conditions, it is found that microwave AMSR observations cannot provide more additional SST information, otherwise it will reduce the spatial variability of the SST products.
2013, 35(4): 98-105.
doi: 10.3969/j.issn.0253-4193.2013.04.012
Abstract:
The temporal and spatial distribution of a chlorophyll a (Chl-a) concentration in the northern South China Sea (NSCS) and its relationship with marine environmental factors were studied based on the annually and monthly mean images (January 2007 to December 2010) of the Chl-a concentration, which were obtained from the MODIS chlorophyll a concentration Level 2 products, then classified into seven regions based on the isobaths and divided into six grades. The preliminary results showed that during 2007-2010 in the NSCS, the highest value area(>5 mg/m3) of Chl-a concentration was mainly distributed in Guangdong coastal estuaries, and the biggest in summer, followed in spring and autumn, the smallest in winter; The second highest value area(1.0～5.0 mg/m3) of the Chl-a concentration was mainly in the waters between coastline and 50m isobaths. The distribution range of Chl-a concentration in summer and winter was larger, extending to the vicinity the 50 m isobath, smaller in spring and autumn, keeping within 50 m isobath; the mid-value area(0.3～1.0 mg/m3) of the Chl-a concentration mainly distrubuted between 50 and 100 m isobath with complex temporal and spatial variation; the low value area(<0.3 mg/m3) of the Chl-a concentration distributed basically in the waters beyond the 100 m isobath, where the regional average of monthly mean Chl-a concentration was the lowest in summer, followed by spring and autumn, the highest in winter, and where the spatial distributions of the Chl-a concentration were homogeneous in spring, summer and autumn, but due to the monsoon and the intrusion of Kuroshio, became more complex in winter. The temporal and spatial features of the Chl-a concentration in the NSCS were affected by the variations of the marine environmental factors, such as monsoon, coastal rivers, ocean currents, sea surface temperature, etc．
The temporal and spatial distribution of a chlorophyll a (Chl-a) concentration in the northern South China Sea (NSCS) and its relationship with marine environmental factors were studied based on the annually and monthly mean images (January 2007 to December 2010) of the Chl-a concentration, which were obtained from the MODIS chlorophyll a concentration Level 2 products, then classified into seven regions based on the isobaths and divided into six grades. The preliminary results showed that during 2007-2010 in the NSCS, the highest value area(>5 mg/m3) of Chl-a concentration was mainly distributed in Guangdong coastal estuaries, and the biggest in summer, followed in spring and autumn, the smallest in winter; The second highest value area(1.0～5.0 mg/m3) of the Chl-a concentration was mainly in the waters between coastline and 50m isobaths. The distribution range of Chl-a concentration in summer and winter was larger, extending to the vicinity the 50 m isobath, smaller in spring and autumn, keeping within 50 m isobath; the mid-value area(0.3～1.0 mg/m3) of the Chl-a concentration mainly distrubuted between 50 and 100 m isobath with complex temporal and spatial variation; the low value area(<0.3 mg/m3) of the Chl-a concentration distributed basically in the waters beyond the 100 m isobath, where the regional average of monthly mean Chl-a concentration was the lowest in summer, followed by spring and autumn, the highest in winter, and where the spatial distributions of the Chl-a concentration were homogeneous in spring, summer and autumn, but due to the monsoon and the intrusion of Kuroshio, became more complex in winter. The temporal and spatial features of the Chl-a concentration in the NSCS were affected by the variations of the marine environmental factors, such as monsoon, coastal rivers, ocean currents, sea surface temperature, etc．
2013, 35(4): 106-111.
doi: 10.3969/j.issn.0253-4193.2013.04.013
Abstract:
The statistical results of major elements in the sediments collected from northern slope of the South China Sea indicate that the terrestrial element association are Ti,Al,Fe,K,Mn,Mg. The comparison of the Ti normalized ratios of the major elements curves (such as Al/Ti、Fe/Ti and K/Ti) and planktonic foraminifera oxygen isotopic curve are presented that, during the cooling events (Heinrich event, Younger Dryas event, PME event), the terrestrial major element ratios decreased significantly. On one side, these characteristics of major elements show that the cooling events might influence the chemical weathering intensity in terrigenous area, on the other, it also plays an obvious indication role in short time scales climate changes, which is similar to indicating large time scales climate changes．
The statistical results of major elements in the sediments collected from northern slope of the South China Sea indicate that the terrestrial element association are Ti,Al,Fe,K,Mn,Mg. The comparison of the Ti normalized ratios of the major elements curves (such as Al/Ti、Fe/Ti and K/Ti) and planktonic foraminifera oxygen isotopic curve are presented that, during the cooling events (Heinrich event, Younger Dryas event, PME event), the terrestrial major element ratios decreased significantly. On one side, these characteristics of major elements show that the cooling events might influence the chemical weathering intensity in terrigenous area, on the other, it also plays an obvious indication role in short time scales climate changes, which is similar to indicating large time scales climate changes．
2013, 35(4): 112-120.
doi: 10.3969/j.issn.0253-4193.2013.04.014
Abstract:
Mound-shaped reflections of Miocene Meishan formation are widely developed in southern Qiongdongnan Basin. Their identification and analysis are of important significance both for sedimentology research and hydrocarbon exploration. They are mainly located in the Beijiao depression and its surrounding slopes, with high amplitudes on top and bottom interfaces and weak reflections in its interior. Sometimes lateral drape reflections exist on the mound top and mounds migrate in a way of growth from structural depression toward higher slopes. In addition of the comprehensive analysis of the palaeotectonic and paleogeographic background, geometry and distribution and impedance of mound-shaped reflections suggest that they should not probably originated by reef or/and mud diapirs and volcanoes. Instead they may be contour currents deposits or some kind of sediment wave formed under the bottom currents in deep-water environment.
Mound-shaped reflections of Miocene Meishan formation are widely developed in southern Qiongdongnan Basin. Their identification and analysis are of important significance both for sedimentology research and hydrocarbon exploration. They are mainly located in the Beijiao depression and its surrounding slopes, with high amplitudes on top and bottom interfaces and weak reflections in its interior. Sometimes lateral drape reflections exist on the mound top and mounds migrate in a way of growth from structural depression toward higher slopes. In addition of the comprehensive analysis of the palaeotectonic and paleogeographic background, geometry and distribution and impedance of mound-shaped reflections suggest that they should not probably originated by reef or/and mud diapirs and volcanoes. Instead they may be contour currents deposits or some kind of sediment wave formed under the bottom currents in deep-water environment.
2013, 35(4): 121-128.
doi: 10.3969/j.issn.0253-4193.2013.04.015
Abstract:
Decadal variations in the erosion/deposition pattern of the Hangzhou Bay and their physical mechanism in recent years have been studied based on the bathymetrical data in 1959, 2003 and 2010, and historical changes of sediment supply from the Changjiang River and erosion/deposition in Qiantang estuary. The results show that (1) the upstream of Hangzhou Bay have been obviously deposited since 1959, and the deposition is featured by a developing trend toward downstream; (2) local bathymetry have been adjusted in the last half century, some small-scale shoal-channel systems have disappeared and the northern bank of the bay mouth have been been eroded since 2003 while it was deposited before 2003; (3) during 1959-2003 and 2003-2010, the annually-averaged sediments deposited in Hangzhou Bay are 0.91×108 and 1.66×108 m3, respectively, and the corresponding deposition rates are0.2 and 9.3 mm/a; (4) the effects of the dramatic reduction of sediment supply from Changjiang River have been not obvious for the whole Qiantang Estuary, i.e. from the Hangzhou Bay mouth to Zakou section, furthermore, the annually-averaged deposition rate after 2003 is a little more than that before 2003. This is probably caused by the land reclamation of the Qiantang Estuary in the past. The erosion/deposition pattern of the Hangzhou Bay in recent 50 a is a result of morphological response of both large and small river basin-estuary systems to human activities.
Decadal variations in the erosion/deposition pattern of the Hangzhou Bay and their physical mechanism in recent years have been studied based on the bathymetrical data in 1959, 2003 and 2010, and historical changes of sediment supply from the Changjiang River and erosion/deposition in Qiantang estuary. The results show that (1) the upstream of Hangzhou Bay have been obviously deposited since 1959, and the deposition is featured by a developing trend toward downstream; (2) local bathymetry have been adjusted in the last half century, some small-scale shoal-channel systems have disappeared and the northern bank of the bay mouth have been been eroded since 2003 while it was deposited before 2003; (3) during 1959-2003 and 2003-2010, the annually-averaged sediments deposited in Hangzhou Bay are 0.91×108 and 1.66×108 m3, respectively, and the corresponding deposition rates are0.2 and 9.3 mm/a; (4) the effects of the dramatic reduction of sediment supply from Changjiang River have been not obvious for the whole Qiantang Estuary, i.e. from the Hangzhou Bay mouth to Zakou section, furthermore, the annually-averaged deposition rate after 2003 is a little more than that before 2003. This is probably caused by the land reclamation of the Qiantang Estuary in the past. The erosion/deposition pattern of the Hangzhou Bay in recent 50 a is a result of morphological response of both large and small river basin-estuary systems to human activities.
2013, 35(4): 129-141.
doi: 10.3969/j.issn.0253-4193.2013.04.016
Abstract:
To improve navigability of the major access channel into Shanghai Harbor, a large-scale Deep Waterway Project (DWP) was carried out in the North Passage (NP) of the Yangtze Estuary. Training walls, groins and channel dredging directly transformed the natural geometry of the estuary. Besides, the engineering constructions greatly hindered the exchanges of water and sediment between the NP and adjacent bar areas. Changes in the characteristics of hydrodynamics and sediment dynamics were accessed by statistical analysis on the data of flow and suspended sediment concentration (SSC), which were collected simultaneously at several locations along the main channel of the NP prior to and after the engineering works. The results show that the decreased ebb flow diversion from the South Channel and the overbanking flood tidal currents from the Jiuduan Shoal caused an increase in the flood tidal volume and an decrease in the ebb tidal volume in the distributrary inlet and upper reach, while the concentrating of flow into the main channel by the training walls and groins caused an increase in the ebb tidal volume in the lower reach. The analysis on the mechanisms of sediment transport reveals that Euler residual flow, tidal pumping, Stokes effect and vertical-longitudinal circulation are main forcing agents leading to residual sediment transport. Euler residual flow caused seaward transport, while Stokes effect and vertical-longitudinal circulation caused landward transport. Sediment transport due to tidal pumping varied with seasons. During wet seasons, the transports due to Euler residual flow and tidal pumping significantly changed, leading to the change in the along-channel distribution of the net sediment transport in a spring tidal cycle, which suggests an overall sediment accumulation in the middle and lower reach prior to the DWP but accumulation in the upper half of the middle reach after the DWP. During dry seasons, the divergent pattern of sediment transport due to tidal pumping resulted in sediment resuspension in most part of the channel, with sediment accumulation in the distributrary inlet after the DWP.
To improve navigability of the major access channel into Shanghai Harbor, a large-scale Deep Waterway Project (DWP) was carried out in the North Passage (NP) of the Yangtze Estuary. Training walls, groins and channel dredging directly transformed the natural geometry of the estuary. Besides, the engineering constructions greatly hindered the exchanges of water and sediment between the NP and adjacent bar areas. Changes in the characteristics of hydrodynamics and sediment dynamics were accessed by statistical analysis on the data of flow and suspended sediment concentration (SSC), which were collected simultaneously at several locations along the main channel of the NP prior to and after the engineering works. The results show that the decreased ebb flow diversion from the South Channel and the overbanking flood tidal currents from the Jiuduan Shoal caused an increase in the flood tidal volume and an decrease in the ebb tidal volume in the distributrary inlet and upper reach, while the concentrating of flow into the main channel by the training walls and groins caused an increase in the ebb tidal volume in the lower reach. The analysis on the mechanisms of sediment transport reveals that Euler residual flow, tidal pumping, Stokes effect and vertical-longitudinal circulation are main forcing agents leading to residual sediment transport. Euler residual flow caused seaward transport, while Stokes effect and vertical-longitudinal circulation caused landward transport. Sediment transport due to tidal pumping varied with seasons. During wet seasons, the transports due to Euler residual flow and tidal pumping significantly changed, leading to the change in the along-channel distribution of the net sediment transport in a spring tidal cycle, which suggests an overall sediment accumulation in the middle and lower reach prior to the DWP but accumulation in the upper half of the middle reach after the DWP. During dry seasons, the divergent pattern of sediment transport due to tidal pumping resulted in sediment resuspension in most part of the channel, with sediment accumulation in the distributrary inlet after the DWP.
2013, 35(4): 142-154.
doi: 10.3969/j.issn.0253-4193.2013.04.017
Abstract:
Based on the data obtained in four seasonal surveys during 2006-2007 in the southern Huanghai (Yellow) Sea Cold Water Mass area, the seasonal evolution of dissolved oxygen(DO), chlorophyll a(Chl a)maximum phenomena and nutrient accumulating process was analyzed.The result showed that:(1)From spring to autumn, the depth of DO and Chl a maximum layer had the trend of deepening first and then shallowing, the scope of DO and Chl a maximum layer increased firstly and then decreased, the depth and scope of DO and Chl a maximum layer were the largest in summer;the DO and Chl a maximum phenomena disappeared in winter.(2)In DO maximum layer in the deep waters of the cold water mass in summer, DO concentration in summer was higher than in spring, while in DO maximum layer in the boundary area of the cold water mass in summer, DO concentration in summer was lower than in spring.(3)From spring to autumn, Chl a concentration in Chl a maximum layer had the trend of decreasing firstly and then increasing, and it was the lowest in summer;in Chl a maximum layer located in the frontal region of the cold water mass in summer, Chl a concentration in summer was the largest all the year round, and was much higher than in deep waters.(4)The nutrient storage in the bottom cold water mass area of the southern Huanghai Sea had spatial heterogeneity, generally, there was a high-concentration core of nutrients in the deep waters and the boundary region of the cold water mass area respectively, the one situating in the deep water had the fixed position on the whole all the year round, while the one located in the boundary region of the cold water mass moved westward from spring to summer, and then moved eastward again when autumn was coming.(5)Hydrological factors and bio-chemical effect played an important role in regulating the seasonal evolution of the DO and Chl a maximum phenomena as well the nutrient storage．
Based on the data obtained in four seasonal surveys during 2006-2007 in the southern Huanghai (Yellow) Sea Cold Water Mass area, the seasonal evolution of dissolved oxygen(DO), chlorophyll a(Chl a)maximum phenomena and nutrient accumulating process was analyzed.The result showed that:(1)From spring to autumn, the depth of DO and Chl a maximum layer had the trend of deepening first and then shallowing, the scope of DO and Chl a maximum layer increased firstly and then decreased, the depth and scope of DO and Chl a maximum layer were the largest in summer;the DO and Chl a maximum phenomena disappeared in winter.(2)In DO maximum layer in the deep waters of the cold water mass in summer, DO concentration in summer was higher than in spring, while in DO maximum layer in the boundary area of the cold water mass in summer, DO concentration in summer was lower than in spring.(3)From spring to autumn, Chl a concentration in Chl a maximum layer had the trend of decreasing firstly and then increasing, and it was the lowest in summer;in Chl a maximum layer located in the frontal region of the cold water mass in summer, Chl a concentration in summer was the largest all the year round, and was much higher than in deep waters.(4)The nutrient storage in the bottom cold water mass area of the southern Huanghai Sea had spatial heterogeneity, generally, there was a high-concentration core of nutrients in the deep waters and the boundary region of the cold water mass area respectively, the one situating in the deep water had the fixed position on the whole all the year round, while the one located in the boundary region of the cold water mass moved westward from spring to summer, and then moved eastward again when autumn was coming.(5)Hydrological factors and bio-chemical effect played an important role in regulating the seasonal evolution of the DO and Chl a maximum phenomena as well the nutrient storage．
2013, 35(4): 155-161.
doi: 10.3969/j.issn.0253-4193.2013.04.018
Abstract:
A high resolution sediment core was selected in the Zhejiang coastal mud area, which was also located within the hypoxia area. The biomarkers, such as brassicasterol, dinosterol and C37 Alkenone were determined on the 210Pb-dated sediment core. According to the vertical distribution of the biomarkers and ratios in the core sediments, we reconstructed the changes in phytoplankton productivity and community structure over the last 110 years in the Zhejiang coastal region. The results indicated increased phytoplankton productivity during the last 100 years in the mud area. Phytoplankton productivity increased gradually starting in the 1960s and accelerated after the 1980s. The change of phytoplankton community structure showed an increasing relative contribution of dinoflagellates and a decreasing relative contribution of diatoms over the last 100 years. The increase in phytoplankton productivity in the Zhejiang coastal mud area corresponded to the increased use of fertilizer and nitrogen fluxes from the Changjiang River during the last 50 years. Meanwhile the succession of diatoms to dinoflagellates was probably caused by the increasing trends in N∶P and N∶Si ratios. We suggested that these variations were mainly caused by the increasing anthropogenic activities such as the industrialization, agricultural development and the construction of dams since the 1960s and especially since the 1980s.
A high resolution sediment core was selected in the Zhejiang coastal mud area, which was also located within the hypoxia area. The biomarkers, such as brassicasterol, dinosterol and C37 Alkenone were determined on the 210Pb-dated sediment core. According to the vertical distribution of the biomarkers and ratios in the core sediments, we reconstructed the changes in phytoplankton productivity and community structure over the last 110 years in the Zhejiang coastal region. The results indicated increased phytoplankton productivity during the last 100 years in the mud area. Phytoplankton productivity increased gradually starting in the 1960s and accelerated after the 1980s. The change of phytoplankton community structure showed an increasing relative contribution of dinoflagellates and a decreasing relative contribution of diatoms over the last 100 years. The increase in phytoplankton productivity in the Zhejiang coastal mud area corresponded to the increased use of fertilizer and nitrogen fluxes from the Changjiang River during the last 50 years. Meanwhile the succession of diatoms to dinoflagellates was probably caused by the increasing trends in N∶P and N∶Si ratios. We suggested that these variations were mainly caused by the increasing anthropogenic activities such as the industrialization, agricultural development and the construction of dams since the 1960s and especially since the 1980s.
2013, 35(4): 162-167.
doi: 10.3969/j.issn.0253-4193.2013.04.019
Abstract:
Screening, cloning and bioinformatics analysis of P23 gene differently expressed in large female and small female of Litopenaeus vannamei.Suppression subtractive hybridization (SSH) approach was used to isolate differently expressed genes in abdominal muscle samples of the female-shrimp between large female (LF; body weight>90 percentile of weight distribution curve) and small female (SF; body weight<10 percentile of weight distribution curve). Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) was used to analysis the change of P23 mRNA level between large female and small female, and biotechnology were employed to predict gene specific structure and potential motif domain.The subtraction efficiency was estimated by a housekeeping gene β-actin, and the results showed that β-actin was subtracted efficiently at 210 and 25 folds for SF and LF subtracted cDNA library respectively. RT-QPCR showed that the P23 has an effect to up-regulated expression in weight gain. Whole length of the P23 gene from Litopenaeus vannamei was 495bp (186 amino acid residues). The sequence has been accessed in GenBank (JF806619). Partial sequence of the P23 gene had strong hydrophobicity but with no transmembrane helices structure. The signal peptide prediction in P23 gene showed that there was a signal peptide with strong amino acid residues in the partial Sequence of the P23 gene．
Screening, cloning and bioinformatics analysis of P23 gene differently expressed in large female and small female of Litopenaeus vannamei.Suppression subtractive hybridization (SSH) approach was used to isolate differently expressed genes in abdominal muscle samples of the female-shrimp between large female (LF; body weight>90 percentile of weight distribution curve) and small female (SF; body weight<10 percentile of weight distribution curve). Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) was used to analysis the change of P23 mRNA level between large female and small female, and biotechnology were employed to predict gene specific structure and potential motif domain.The subtraction efficiency was estimated by a housekeeping gene β-actin, and the results showed that β-actin was subtracted efficiently at 210 and 25 folds for SF and LF subtracted cDNA library respectively. RT-QPCR showed that the P23 has an effect to up-regulated expression in weight gain. Whole length of the P23 gene from Litopenaeus vannamei was 495bp (186 amino acid residues). The sequence has been accessed in GenBank (JF806619). Partial sequence of the P23 gene had strong hydrophobicity but with no transmembrane helices structure. The signal peptide prediction in P23 gene showed that there was a signal peptide with strong amino acid residues in the partial Sequence of the P23 gene．
Seasonal variability of zooplankton community characteristics in the Rongcheng Bay contiguous waters
2013, 35(4): 168-175.
doi: 10.3969/j.issn.0253-4193.2013.04.020
Abstract:
Based on the field survey data in February, May, August and November 2009, seasonal variability of zooplankton community characteristics in the Rongcheng Bay contiguous waters were studied. A total of 59 zooplankton species (pelagic larvae included) were identified in the four cruises. There were more than 30 species in the autumn, summer and spring, with 38, 35 and 32 species respectively, which were much more than that in winter (22 species). Aidanosagitta crassa, Calanus sinicus, Paracalanus parvus and Oithona similes were the main dominant species in the study region, and their spatial and seasonal distributions varied very much. The zooplankton biomass (wet weight) averaged 433.8 mg/m3 in winter (highest), 220.7 mg/m3 in spring, 162.4 mg/m3 in autumn and 52.5 mg/m3 in summer (lowest). The diversity index H′ of zooplankton community averaged 2.50 in this study, and the evenness index J′ averaged 0.65. The results showed that diversity and evenness were higher in summer and lower in spring, suggesting that the zooplankton community in summer were more stable than that in spring. Further analysis concluded that the raft aquaculture in the coastal waters had significant impacts on the distribution of the zooplankton community in the Rongcheng Bay contiguous waters．
Based on the field survey data in February, May, August and November 2009, seasonal variability of zooplankton community characteristics in the Rongcheng Bay contiguous waters were studied. A total of 59 zooplankton species (pelagic larvae included) were identified in the four cruises. There were more than 30 species in the autumn, summer and spring, with 38, 35 and 32 species respectively, which were much more than that in winter (22 species). Aidanosagitta crassa, Calanus sinicus, Paracalanus parvus and Oithona similes were the main dominant species in the study region, and their spatial and seasonal distributions varied very much. The zooplankton biomass (wet weight) averaged 433.8 mg/m3 in winter (highest), 220.7 mg/m3 in spring, 162.4 mg/m3 in autumn and 52.5 mg/m3 in summer (lowest). The diversity index H′ of zooplankton community averaged 2.50 in this study, and the evenness index J′ averaged 0.65. The results showed that diversity and evenness were higher in summer and lower in spring, suggesting that the zooplankton community in summer were more stable than that in spring. Further analysis concluded that the raft aquaculture in the coastal waters had significant impacts on the distribution of the zooplankton community in the Rongcheng Bay contiguous waters．
2013, 35(4): 176-187.
doi: 10.3969/j.issn.0253-4193.2013.04.021
Abstract:
The composition and distribution of picoplankton were mainly investigated in the southern Yellow Sea in summer. The effects of main environmental factors were also discussed in the study. The seawater samples were analyzed using Flow Cytometer, and the average abundance of Synechococcus, picoeukaryotes and bacteria were at order of 1×104, 1×103, 1×106 cells/mL, respectively. The influence of environmental factors including temperature, salinity, nutrients and light on picoplankton were discussed. The results revealed that the picoplankton were limited obviously by temperature and light, but less limited by nutrients. Only in the offshore, the influence of nutrients was reflected by the abnormal high picoplankton abundance. Bacteria were limited little by the environmental factors for their high environment adaptability, and they could keep high abundance even in the deep water.
The composition and distribution of picoplankton were mainly investigated in the southern Yellow Sea in summer. The effects of main environmental factors were also discussed in the study. The seawater samples were analyzed using Flow Cytometer, and the average abundance of Synechococcus, picoeukaryotes and bacteria were at order of 1×104, 1×103, 1×106 cells/mL, respectively. The influence of environmental factors including temperature, salinity, nutrients and light on picoplankton were discussed. The results revealed that the picoplankton were limited obviously by temperature and light, but less limited by nutrients. Only in the offshore, the influence of nutrients was reflected by the abnormal high picoplankton abundance. Bacteria were limited little by the environmental factors for their high environment adaptability, and they could keep high abundance even in the deep water.
2013, 35(4): 188-200.
doi: 10.3969/j.issn.0253-4193.2013.04.022
Abstract:
Nine common species of red seaweeds were collected from the coasts of Qingdao Shandong, Nantong Jiangsu and Xiangshan Zhejiang area, which could be classified into 2 classes, 5 orders, 6 families, 8 genus (according to the NCBI). The hsp 70 genes were amplified by PCR from 9 red seaweeds, phylogenetic analysis were carried out based on the hsp70 gene and HSP 70 protein sequences. The obtained target bands amplified by the primers P1/P3 were about 630bp, which were presumed located near the ATPs domain based on the HSPs sequences analysis The distances of hsp70 sequences within 9 red seaweeds were between 0.078 and 0.319, and the similarities of sequences were between 73% and 92%, which conservation were slightly lower than their HSP70 proteins. The codons ended with A and T were preferred in the hsp70 genes of these 9 red seaweeds while the codons of CGC and TGG were not founded. The results of the phylogenetic analysis of hsp70, 18S rDNA and rbcL sequences in other algae, microbes and plants obtained from GenBank suggested that the origin of the primitive red algae Cyanidium caldarium and Cyanidioschyzon merolae strain 10D were more primordially than the other red algae, while the Pyropia species were followed, and the phylogenesis of the 9 species of red seaweeds studied in this paper were coherent with those described in NCBI. The difference of nutrition mode might be the basic factor of HSP 70 differentiation in fungi, algae and plant, while the adaptation to variable environment was the major factor in biological molecular evolution when the organisms were at the same morphological levels, which made the species much stronger in stress resistance and more stable in genetic structures.
Nine common species of red seaweeds were collected from the coasts of Qingdao Shandong, Nantong Jiangsu and Xiangshan Zhejiang area, which could be classified into 2 classes, 5 orders, 6 families, 8 genus (according to the NCBI). The hsp 70 genes were amplified by PCR from 9 red seaweeds, phylogenetic analysis were carried out based on the hsp70 gene and HSP 70 protein sequences. The obtained target bands amplified by the primers P1/P3 were about 630bp, which were presumed located near the ATPs domain based on the HSPs sequences analysis The distances of hsp70 sequences within 9 red seaweeds were between 0.078 and 0.319, and the similarities of sequences were between 73% and 92%, which conservation were slightly lower than their HSP70 proteins. The codons ended with A and T were preferred in the hsp70 genes of these 9 red seaweeds while the codons of CGC and TGG were not founded. The results of the phylogenetic analysis of hsp70, 18S rDNA and rbcL sequences in other algae, microbes and plants obtained from GenBank suggested that the origin of the primitive red algae Cyanidium caldarium and Cyanidioschyzon merolae strain 10D were more primordially than the other red algae, while the Pyropia species were followed, and the phylogenesis of the 9 species of red seaweeds studied in this paper were coherent with those described in NCBI. The difference of nutrition mode might be the basic factor of HSP 70 differentiation in fungi, algae and plant, while the adaptation to variable environment was the major factor in biological molecular evolution when the organisms were at the same morphological levels, which made the species much stronger in stress resistance and more stable in genetic structures.
2013, 35(4): 201-207.
doi: 10.3969/j.issn.0253-4193.2013.04.023
Abstract:
Using “Beijing No.1” small satellite panchromatic and multispectral images the sea ice in the Bohai Sea in winter was monitored.According to the corres-pondence between spectral characteristics of multispectral and field testing of the ice spectrum, water and ice satellite image recognition model and the outer edge of sea ice recognition model are established to estimate the sea ice area and analysis sea ice trends.According to sea ice type the ice area was divided to classify the severity of the ice disaster.For example, winter of 2007, the statistical area of sea ice is close to the results of the operational inversion MODIS data.“Beijing No.1” satellite can provide high-resolution remote sensing of sea ice for the ocean monitoring and forecasting service.And it provide reliable and effective disaster information for the comprehensive survey and evaluation of offshore marine sea ice surveys.
Using “Beijing No.1” small satellite panchromatic and multispectral images the sea ice in the Bohai Sea in winter was monitored.According to the corres-pondence between spectral characteristics of multispectral and field testing of the ice spectrum, water and ice satellite image recognition model and the outer edge of sea ice recognition model are established to estimate the sea ice area and analysis sea ice trends.According to sea ice type the ice area was divided to classify the severity of the ice disaster.For example, winter of 2007, the statistical area of sea ice is close to the results of the operational inversion MODIS data.“Beijing No.1” satellite can provide high-resolution remote sensing of sea ice for the ocean monitoring and forecasting service.And it provide reliable and effective disaster information for the comprehensive survey and evaluation of offshore marine sea ice surveys.
2013, 35(4): 208-213.
doi: 10.3969/j.issn.0253-4193.2013.04.024
Abstract:
The data of significant wave height (SWH) obtained with “HY-2” and other satellite altimeters from October 1, 2011 to March 8, 2012 are merged by using the inverse distance to a power method in the different combination. The data fusion results are compared with the NDBC buoy data. The comparisons indicate that:(1) all the data fusion in different combinations could reflect the real situation of sea surface; (2)the data of the SWH measured with “HY-2” altimetry can work well in the multisatellite altimeters data fusion and even can take the place of EVNISAT for its sudden lost.
The data of significant wave height (SWH) obtained with “HY-2” and other satellite altimeters from October 1, 2011 to March 8, 2012 are merged by using the inverse distance to a power method in the different combination. The data fusion results are compared with the NDBC buoy data. The comparisons indicate that:(1) all the data fusion in different combinations could reflect the real situation of sea surface; (2)the data of the SWH measured with “HY-2” altimetry can work well in the multisatellite altimeters data fusion and even can take the place of EVNISAT for its sudden lost.
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