2013 Vol. 35, No. 3
Display Method:
2013, 35(3): 1-10.
doi: 10.3969/j.issn.0253-4193.2013.03.001
Abstract:
On the basis of the cruising data of Lowered Acoustic Doppler Current Profilers (LADCP) and ship-mounted ADCP (SADCP) and so forth, during the cruise of Luzon Strait in April 2008, velocity profile is figured out using the LDEO LADCP processing software. We take use of the simulating results of TPXO7.2 (a TOPEX/POSEIDON global tidal model) to remove the tidal current speed from the measured value. The following main results have been obtained: the core of intruding Kuroshio flows through station C2, C7, C8 and C9, respectively, and the positions of core agree basically with those in spring 1992. At station C2 the Kuroshio is located in the upper layer from sea surface to 400 m with the maximum westward speed 77 cm/s, and its speed decreases with the increase of water depths. At station C7, C8, C9, the Kuroshio is located in the layer from surface to 500 m, depth of the Kuroshio becomes shallow gradually when it intrudes into the South China Sea. The observation results may be a support to the sandwiched vertical structure of Luzon Strait transport.
On the basis of the cruising data of Lowered Acoustic Doppler Current Profilers (LADCP) and ship-mounted ADCP (SADCP) and so forth, during the cruise of Luzon Strait in April 2008, velocity profile is figured out using the LDEO LADCP processing software. We take use of the simulating results of TPXO7.2 (a TOPEX/POSEIDON global tidal model) to remove the tidal current speed from the measured value. The following main results have been obtained: the core of intruding Kuroshio flows through station C2, C7, C8 and C9, respectively, and the positions of core agree basically with those in spring 1992. At station C2 the Kuroshio is located in the upper layer from sea surface to 400 m with the maximum westward speed 77 cm/s, and its speed decreases with the increase of water depths. At station C7, C8, C9, the Kuroshio is located in the layer from surface to 500 m, depth of the Kuroshio becomes shallow gradually when it intrudes into the South China Sea. The observation results may be a support to the sandwiched vertical structure of Luzon Strait transport.
2013, 35(3): 11-17.
doi: 10.3969/j.issn.0253-4193.2013.03.002
Abstract:
Based on the 19 years sea surface height(SSH) of tide gauge stations and satellite altimeter, the seasonal variation and the long term trend of SSH in the Sansha seas are investigated. The results show that the sea level takes on significant seasonal variation and regional characteristics in the Sansha seas. The SSH also shows prominent inter-annual variation besides the seasonal variation. The prominent terms are 2~3 a, 4~7 a and quasi-9 a. According to 19 a SSH data in the Sansha seas, the SSH shows obvious increasing trend, the average rising rate is 4.9 mm/a, the increasing range in the south of Paracel Islands is the most, the weakest in the western of Nansha Islands. Affected by abnormal atmospheric circulation and other climate events, fluctuations in the inter-annual variability of the sea level in 1998 and 2010. According to the analyzing results of the sea level forecasting model, it is predicted that in the coming 20 a, 40 a, 60 a and 90 a, sea level of Sansha seas will rise by 11 cm, 20 cm, 30 cm and 45 cm in comparison with the multi-year average.
Based on the 19 years sea surface height(SSH) of tide gauge stations and satellite altimeter, the seasonal variation and the long term trend of SSH in the Sansha seas are investigated. The results show that the sea level takes on significant seasonal variation and regional characteristics in the Sansha seas. The SSH also shows prominent inter-annual variation besides the seasonal variation. The prominent terms are 2~3 a, 4~7 a and quasi-9 a. According to 19 a SSH data in the Sansha seas, the SSH shows obvious increasing trend, the average rising rate is 4.9 mm/a, the increasing range in the south of Paracel Islands is the most, the weakest in the western of Nansha Islands. Affected by abnormal atmospheric circulation and other climate events, fluctuations in the inter-annual variability of the sea level in 1998 and 2010. According to the analyzing results of the sea level forecasting model, it is predicted that in the coming 20 a, 40 a, 60 a and 90 a, sea level of Sansha seas will rise by 11 cm, 20 cm, 30 cm and 45 cm in comparison with the multi-year average.
2013, 35(3): 18-27.
doi: 10.3969/j.issn.0253-4193.2013.03.003
Abstract:
The warm tendency of climate change in winters for the Bohai Sea and the north Huanghai Sea is taken under the globe warmer climate change. The air temperature of the behind 30 a is 1.6℃ higher than the former 30 a within the 60 a (1951-2010), it seems quite remarkable. During the period, the ice grade for the Bohai Sea and the North Huanghai Sea drops 0.6 (total 5 levels). The temperature abnormity higher in winters for the Bohai Sea and the North Huanghai Sea responds with the general circulation of the globe and the Eastern Asia. The physical mechanism mentioned above is distinct. The research is important for the sea ice forecast of the Bohai Sea and the North Huanghai Sea.
The warm tendency of climate change in winters for the Bohai Sea and the north Huanghai Sea is taken under the globe warmer climate change. The air temperature of the behind 30 a is 1.6℃ higher than the former 30 a within the 60 a (1951-2010), it seems quite remarkable. During the period, the ice grade for the Bohai Sea and the North Huanghai Sea drops 0.6 (total 5 levels). The temperature abnormity higher in winters for the Bohai Sea and the North Huanghai Sea responds with the general circulation of the globe and the Eastern Asia. The physical mechanism mentioned above is distinct. The research is important for the sea ice forecast of the Bohai Sea and the North Huanghai Sea.
2013, 35(3): 28-35.
doi: 10.3969/j.issn.0253-4193.2013.03.004
Abstract:
Based on SODA datasets and the tropical cyclone data from Unisys Weather, the heat content distribution characteristics of upper ocean 150 m and its relationship between tropical cyclone frequency in the northwest Pacific from 1960 to 2008 are studied. After considering the changes of heat content with latitudes, the maximum heat content in the North Pacific is located at 10°N, which is consistent with the upper ocean temperature structures and more reasonable in physics.The relationships of the heat content in the North Pacific and tropical cyclone frequency in the northwest Pacific show pre-winter positive correlation in the middle and high latitudes of the interior North Pacific and equatorial eastern Pacific where tropical instability waves occurred. And the correlation coefficient show significant interdecadal variations which indicate stronger correlation from 1970 to 1976 and 1984 to 2008 and weaker from 1975 to 1983. In the middle and high latitudes of the interior North Pacific, the same summer and autumn also have strong positive correlation. In the western Pacific warm pool, the negative correlation in the same autumn is most significant. The equatorial middle Pacific shows a significant positive correlation in the summer and autumn. In the equatorial eastern Pacific, the pre-winter negative correlation is most significant, negative correlation weakened in the same spring, and no significant correlation in summer and autumn.
Based on SODA datasets and the tropical cyclone data from Unisys Weather, the heat content distribution characteristics of upper ocean 150 m and its relationship between tropical cyclone frequency in the northwest Pacific from 1960 to 2008 are studied. After considering the changes of heat content with latitudes, the maximum heat content in the North Pacific is located at 10°N, which is consistent with the upper ocean temperature structures and more reasonable in physics.The relationships of the heat content in the North Pacific and tropical cyclone frequency in the northwest Pacific show pre-winter positive correlation in the middle and high latitudes of the interior North Pacific and equatorial eastern Pacific where tropical instability waves occurred. And the correlation coefficient show significant interdecadal variations which indicate stronger correlation from 1970 to 1976 and 1984 to 2008 and weaker from 1975 to 1983. In the middle and high latitudes of the interior North Pacific, the same summer and autumn also have strong positive correlation. In the western Pacific warm pool, the negative correlation in the same autumn is most significant. The equatorial middle Pacific shows a significant positive correlation in the summer and autumn. In the equatorial eastern Pacific, the pre-winter negative correlation is most significant, negative correlation weakened in the same spring, and no significant correlation in summer and autumn.
2013, 35(3): 36-46.
doi: 10.3969/j.issn.0253-4193.2013.03.005
Abstract:
In this article a tsunami propagation model was built up using the global ocean model GOCTM. This model is based on finite volume discrete method and unstructured triangular Grids. And this is no open boundary condition to be considered. The tsunami event generated by the great Sumatra-Andaman earthquake on 26 December 2004 was simulated with this model. Tsunami source is provided by Alfred Wegener Institute(AWI) in German as the initial surface elevation condition. In order to check the result,we compare model results to tide gauge data from all around the Indian Ocean,to satellite altimetry in selected track. The highest correlation coefficient between model data and tide gauge data is 0.82 proved a good correlation. And the result is satisfactory which prove the GOCTM is suitable to tsunami propagation simulation.
In this article a tsunami propagation model was built up using the global ocean model GOCTM. This model is based on finite volume discrete method and unstructured triangular Grids. And this is no open boundary condition to be considered. The tsunami event generated by the great Sumatra-Andaman earthquake on 26 December 2004 was simulated with this model. Tsunami source is provided by Alfred Wegener Institute(AWI) in German as the initial surface elevation condition. In order to check the result,we compare model results to tide gauge data from all around the Indian Ocean,to satellite altimetry in selected track. The highest correlation coefficient between model data and tide gauge data is 0.82 proved a good correlation. And the result is satisfactory which prove the GOCTM is suitable to tsunami propagation simulation.
2013, 35(3): 47-55.
doi: 10.3969/j.issn.0253-4193.2013.03.006
Abstract:
Relying on the investigation and study, it is verified that the most abnormal places of western North Pacific typhoon frequency is the east part of 150°E in low latitude region. Whats more, having been testified, typhoon frequency is closely related to the 850 hPa atmospheric circulation, latent heat flux and short-wave radiation flux. It is found that when western Pacific subtropical high becomes weaker (stronger) and moves eastward (westward), the westerly in the low latitude region will be strengthened (weakened). Along with the monsoon troughs east movement to 160°E (west movement to 140°E), more (less) latent heat flux will be transmitted from the ocean to the air. A strong (weak) vapor source can be found in the southern of monsoon trough, which is brought by the prevailing (un-prevailing) westerly and then convergences the vapor of the south subtropical high that is embedded in the easterly vapor stream. Meanwhile, the converging upward warm wet vapor cloud clusters absorb plenty (lack) of short-wave radiation flux so (not) as to form a deep-thick high temperature and high humidity unstable structure. Finally, the accumulation of the typhoon energy, together with the strong (weak) lower convergence, and the increase (decrease) of the upper divergence, is beneficial (unbeneficial) to the typhoon generation in the east part of 150°E in the low latitude region.
Relying on the investigation and study, it is verified that the most abnormal places of western North Pacific typhoon frequency is the east part of 150°E in low latitude region. Whats more, having been testified, typhoon frequency is closely related to the 850 hPa atmospheric circulation, latent heat flux and short-wave radiation flux. It is found that when western Pacific subtropical high becomes weaker (stronger) and moves eastward (westward), the westerly in the low latitude region will be strengthened (weakened). Along with the monsoon troughs east movement to 160°E (west movement to 140°E), more (less) latent heat flux will be transmitted from the ocean to the air. A strong (weak) vapor source can be found in the southern of monsoon trough, which is brought by the prevailing (un-prevailing) westerly and then convergences the vapor of the south subtropical high that is embedded in the easterly vapor stream. Meanwhile, the converging upward warm wet vapor cloud clusters absorb plenty (lack) of short-wave radiation flux so (not) as to form a deep-thick high temperature and high humidity unstable structure. Finally, the accumulation of the typhoon energy, together with the strong (weak) lower convergence, and the increase (decrease) of the upper divergence, is beneficial (unbeneficial) to the typhoon generation in the east part of 150°E in the low latitude region.
2013, 35(3): 56-64.
doi: 10.3969/j.issn.0253-4193.2013.03.007
Abstract:
The accuracy of typhoon surge numerical forecasting results mainly depends on the precision of forecasted Typhoon tracks and intensity,but also the precision of storm surge forecast model. Currently, the errors for 24/48 h typhoon forecasted tracks are about 120/210 km.The errors were large for some typhoons with abnormal tracks. The reliability of storm surge forecasting results can not be guaranteed relying solely on single Typhoon track and single-class numerical Typhoon surge forecast models. Multi-grids method can smooth different frequency deviation components in order to accelerate iteration convergence and improve precision by iterative computations among coarse grid and finer grid. A multi-model ensemble numerical typhoon surge forecast system was implemented based on high resolution and refine storm surge ensemble numerical forecast models in this paper. In do so, it can reduce genetic probability for single-class model generating similar errors. The system was valid by testing with typical typhoon surge events which impact China coasts. The results indicate that this technology improves the effects of surge forecast effectively than using single ensemble model, and may be used in the future.
The accuracy of typhoon surge numerical forecasting results mainly depends on the precision of forecasted Typhoon tracks and intensity,but also the precision of storm surge forecast model. Currently, the errors for 24/48 h typhoon forecasted tracks are about 120/210 km.The errors were large for some typhoons with abnormal tracks. The reliability of storm surge forecasting results can not be guaranteed relying solely on single Typhoon track and single-class numerical Typhoon surge forecast models. Multi-grids method can smooth different frequency deviation components in order to accelerate iteration convergence and improve precision by iterative computations among coarse grid and finer grid. A multi-model ensemble numerical typhoon surge forecast system was implemented based on high resolution and refine storm surge ensemble numerical forecast models in this paper. In do so, it can reduce genetic probability for single-class model generating similar errors. The system was valid by testing with typical typhoon surge events which impact China coasts. The results indicate that this technology improves the effects of surge forecast effectively than using single ensemble model, and may be used in the future.
2013, 35(3): 65-77.
doi: 10.3969/j.issn.0253-4193.2013.03.008
Abstract:
When tropical cyclones move over the shallow waters near islands and continents, the influences of the continental shelf and complicated thermodynamic conditions make typhoon forecasts much difficult. For this reason, a coupled model that consists of the hurricane GRAPES-TCM model and the ECOM ocean model has been developed in Shanghai Typhoon Institute of China Meteorological Administration. In order to evaluate the coupled model and understand the response of the western ocean boundary to tropical cyclones, numerical simulations of the landfalling process of Typhoon Morakot (2009) are conducted and compared with the satellite observations, with a focus on sea temperatures, upwelling and ocean currents. The coupled model can reasonably well simulate the dynamic and thermodynamic ocean responses during the landfall process of Typhoon Morakot. In the coastal waters, maximum sea temperature cooling occurred on the left-hand side of the typhoon track during its landfall, mainly due to the strong upwelling along the southeastern coast of Taiwan Island. Then the cold eddy in the Pengjiayu sea area to the northest of Taiwan Island weakened as the typhoon was over the Northwest Pacific and strengthened as the typhoon crossed the Taiwan Strait. The crossing of Morakot increased the mixed layer depth, leading to disappearance of the stratification of sea water in the Taiwan Strait.
When tropical cyclones move over the shallow waters near islands and continents, the influences of the continental shelf and complicated thermodynamic conditions make typhoon forecasts much difficult. For this reason, a coupled model that consists of the hurricane GRAPES-TCM model and the ECOM ocean model has been developed in Shanghai Typhoon Institute of China Meteorological Administration. In order to evaluate the coupled model and understand the response of the western ocean boundary to tropical cyclones, numerical simulations of the landfalling process of Typhoon Morakot (2009) are conducted and compared with the satellite observations, with a focus on sea temperatures, upwelling and ocean currents. The coupled model can reasonably well simulate the dynamic and thermodynamic ocean responses during the landfall process of Typhoon Morakot. In the coastal waters, maximum sea temperature cooling occurred on the left-hand side of the typhoon track during its landfall, mainly due to the strong upwelling along the southeastern coast of Taiwan Island. Then the cold eddy in the Pengjiayu sea area to the northest of Taiwan Island weakened as the typhoon was over the Northwest Pacific and strengthened as the typhoon crossed the Taiwan Strait. The crossing of Morakot increased the mixed layer depth, leading to disappearance of the stratification of sea water in the Taiwan Strait.
2013, 35(3): 78-86.
doi: 10.3969/j.issn.0253-4193.2013.03.009
Abstract:
The stratified conditions of seawater in the Pacific were analyzed and classified based on Argo data. Using internal wave dynamics method, the numerical value of the sound fluctuation caused by the internal wave was solved,and the sound fluctuations in different stratified conditions of seawater were simulated and analyzed. The results show that the vertical mode shape is distorted because of the nonhomogeneous density of seawater and the existence of the pycnocline,and the distortion corresponds to the intensity of pycnocline. And the number and the depths of stratification apexes have good corresponding relationships with the sound fluctuations. In general, sound transmission characteristics with internal wave are similar to the transmission characteristics without internal wave. However, acoustic field responses to the disturbance of internal wave under different stratified conditions are diverse.
The stratified conditions of seawater in the Pacific were analyzed and classified based on Argo data. Using internal wave dynamics method, the numerical value of the sound fluctuation caused by the internal wave was solved,and the sound fluctuations in different stratified conditions of seawater were simulated and analyzed. The results show that the vertical mode shape is distorted because of the nonhomogeneous density of seawater and the existence of the pycnocline,and the distortion corresponds to the intensity of pycnocline. And the number and the depths of stratification apexes have good corresponding relationships with the sound fluctuations. In general, sound transmission characteristics with internal wave are similar to the transmission characteristics without internal wave. However, acoustic field responses to the disturbance of internal wave under different stratified conditions are diverse.
2013, 35(3): 87-95.
doi: 10.3969/j.issn.0253-4193.2013.03.010
Abstract:
Doppler radar reflectivity, radial velocity and unconventional observation data are assimulated by mesoscale numerical model WRF to simulated four strong typhoons landing in Zhejiang and Fujian coast in recent years. The simulated result shows that assimilating radar data could further improve the simulation effect of typhoon track and precipitation distribution and clearly reveal the existence of the strong mesoscale convective system in the spiral cloud band near typhoon center. There is a strong convergence line occurring in the spiral cloud band near typhoon center, which corresponds very well to the observed Doppler CAPPI echo and related closely to the mesoscale heavy rainfall system in the coast area.
Doppler radar reflectivity, radial velocity and unconventional observation data are assimulated by mesoscale numerical model WRF to simulated four strong typhoons landing in Zhejiang and Fujian coast in recent years. The simulated result shows that assimilating radar data could further improve the simulation effect of typhoon track and precipitation distribution and clearly reveal the existence of the strong mesoscale convective system in the spiral cloud band near typhoon center. There is a strong convergence line occurring in the spiral cloud band near typhoon center, which corresponds very well to the observed Doppler CAPPI echo and related closely to the mesoscale heavy rainfall system in the coast area.
2013, 35(3): 96-103.
doi: 10.3969/j.issn.0253-4193.2013.03.011
Abstract:
von Kármán vortex streets in the southeast ocean area off the Jeju Island were observed on 2 March 2011 by using the Chinese Ocean Color Temperature Scanner (COCTS) data onboard Chinese Haiyang-1(HY-1B) satellite. The dynamics of the von Kármán streets were further analyzed in conjunction with observations from Moderate Resolution Imaging Spectroradiometer (MODIS). The averaged ratios(h/a)of the spacing of two atmospheric vortex street rows to that of individual vortex from COCTS and MODIS images are 0.32 and 0.35, respectively. Low wind speed vortices near sea surface and warm SST tongue were also observed in the vortex streets area, as well as an inversion temperature layer in the vertical atmosphere. The displacement speed of the vortices, 12.2 m/s, was computed from two cloud images of COCTS and MODIS in adjacent time, and the values calculated using the geometrical size (h/a) and the dynamical model for the COCTS and MODIS images are 12.8 m/s and 12.3 m/s, respectively. The dynamical parameters of vortex streets were estimated including shedding rate of the atmospheric vortex 1.24×10-4 s-1, shedding period 134 min, Reynolds number 60 to 75, kinematic vortex viscosity 2 200 to 2 750, Froude number 0.10, and Rossby number 0.43. The analyzed results in this study indicate that the Chinese HY-1B satellite data are useful for quantitative studies on oceanic and atmospheric processes, such as von Kármán atmospheric vortex streets.
von Kármán vortex streets in the southeast ocean area off the Jeju Island were observed on 2 March 2011 by using the Chinese Ocean Color Temperature Scanner (COCTS) data onboard Chinese Haiyang-1(HY-1B) satellite. The dynamics of the von Kármán streets were further analyzed in conjunction with observations from Moderate Resolution Imaging Spectroradiometer (MODIS). The averaged ratios(h/a)of the spacing of two atmospheric vortex street rows to that of individual vortex from COCTS and MODIS images are 0.32 and 0.35, respectively. Low wind speed vortices near sea surface and warm SST tongue were also observed in the vortex streets area, as well as an inversion temperature layer in the vertical atmosphere. The displacement speed of the vortices, 12.2 m/s, was computed from two cloud images of COCTS and MODIS in adjacent time, and the values calculated using the geometrical size (h/a) and the dynamical model for the COCTS and MODIS images are 12.8 m/s and 12.3 m/s, respectively. The dynamical parameters of vortex streets were estimated including shedding rate of the atmospheric vortex 1.24×10-4 s-1, shedding period 134 min, Reynolds number 60 to 75, kinematic vortex viscosity 2 200 to 2 750, Froude number 0.10, and Rossby number 0.43. The analyzed results in this study indicate that the Chinese HY-1B satellite data are useful for quantitative studies on oceanic and atmospheric processes, such as von Kármán atmospheric vortex streets.
2013, 35(3): 104-111.
doi: 10.3969/j.issn.0253-4193.2013.03.012
Abstract:
In this study, the third-generation wave model WAVEWATCH -Ⅲ (WW3) was used to simulate the wave field of the China Sea from January 1988 to December 2010, with wind input of CCMP wind field.In order to evaluate the wave energy resources reasonably, significant interval was defined.Synthetically considering the size of energy density, significant interval, stability and long-term trend of wave energy density, wave energy storage, wave energy in the China Sea were analyzed.Results show that, (1) Large area of wave energy density mainly located in the north waters of South China Sea, of above 8 kW/m all year round.(2) Frequency of significant interval in East China Sea and South China Sea is high.(3) Stability of wave energy density in January is better than that in April and October, and in July is the worst.Stability in north waters of South China Sea is much better than that in other areas.(4) Wave energy storage in most of China Sea is large than 2×104kW·h/m, and the large area locates in the north waters of South China Sea.(5) SWH and wave energy density in most of China Sea have significant increasing trend from 1988 to 2010, of 0.5-2.5 cm/a in SWH and 0.05-0.55 kW/(m·a) in wave energy density.(6) There is a rich storage of wave energy in the China sea, especially in the north waters of South China Sea, Ryukyu Islands waters and east area of Taiwan Island.
In this study, the third-generation wave model WAVEWATCH -Ⅲ (WW3) was used to simulate the wave field of the China Sea from January 1988 to December 2010, with wind input of CCMP wind field.In order to evaluate the wave energy resources reasonably, significant interval was defined.Synthetically considering the size of energy density, significant interval, stability and long-term trend of wave energy density, wave energy storage, wave energy in the China Sea were analyzed.Results show that, (1) Large area of wave energy density mainly located in the north waters of South China Sea, of above 8 kW/m all year round.(2) Frequency of significant interval in East China Sea and South China Sea is high.(3) Stability of wave energy density in January is better than that in April and October, and in July is the worst.Stability in north waters of South China Sea is much better than that in other areas.(4) Wave energy storage in most of China Sea is large than 2×104kW·h/m, and the large area locates in the north waters of South China Sea.(5) SWH and wave energy density in most of China Sea have significant increasing trend from 1988 to 2010, of 0.5-2.5 cm/a in SWH and 0.05-0.55 kW/(m·a) in wave energy density.(6) There is a rich storage of wave energy in the China sea, especially in the north waters of South China Sea, Ryukyu Islands waters and east area of Taiwan Island.
2013, 35(3): 112-118.
doi: 10.3969/j.issn.0253-4193.2013.03.013
Abstract:
In the last decades,the remote sensing technology has played a crucial role in the monitoring of the sea-ice in the Bohai Sea. The reflection characteristics of the sea ice are the fundamentals of sea-ice monitoring based on an optical remote sensing. The hemispherical-directional reflectance factor (HDRF)of three paradigmatic classes of level sea-ice collected from the eastern Liaodong Bay during the sea ice maximum is measured under cloudless sky conditions,and related anisotropic factor(ANIF)is also calculated thereafter. The results show that the hemispherical-directional reflectance factor and the anisotropic factor can increase rapidly only near the forward reflection direction within the principle plain of solar incident,while in other viewing directions,the variations of these two factors are insignificant. In addition,the thickness and inner structure of level sea-ice can affect the characteristics of the HDRF and the ANIF with varying wavelength. In the band of 350-1 350 nm,thin level sea-ice with a smooth surface has a relatively small HDRF,and thick level sea-ice has a relatively large HDRF. But in the band of 350~950 nm,absolute conclusions are drawn,thin level sea-ice with the smooth surface has a relatively large ANIF,and thick level sea-ice has a relatively small ANIF. These results suggest that the sea-ice reflection to the solar incident radiation is the combined consequent of ice-atmosphere interface reflection and internal scattering of sea ice.
In the last decades,the remote sensing technology has played a crucial role in the monitoring of the sea-ice in the Bohai Sea. The reflection characteristics of the sea ice are the fundamentals of sea-ice monitoring based on an optical remote sensing. The hemispherical-directional reflectance factor (HDRF)of three paradigmatic classes of level sea-ice collected from the eastern Liaodong Bay during the sea ice maximum is measured under cloudless sky conditions,and related anisotropic factor(ANIF)is also calculated thereafter. The results show that the hemispherical-directional reflectance factor and the anisotropic factor can increase rapidly only near the forward reflection direction within the principle plain of solar incident,while in other viewing directions,the variations of these two factors are insignificant. In addition,the thickness and inner structure of level sea-ice can affect the characteristics of the HDRF and the ANIF with varying wavelength. In the band of 350-1 350 nm,thin level sea-ice with a smooth surface has a relatively small HDRF,and thick level sea-ice has a relatively large HDRF. But in the band of 350~950 nm,absolute conclusions are drawn,thin level sea-ice with the smooth surface has a relatively large ANIF,and thick level sea-ice has a relatively small ANIF. These results suggest that the sea-ice reflection to the solar incident radiation is the combined consequent of ice-atmosphere interface reflection and internal scattering of sea ice.
2013, 35(3): 119-127.
doi: 10.3969/j.issn.0253-4193.2013.03.014
Abstract:
Sea ice brings negative influences on offshore structures, nautical transportation and aquaculture in the Liaodong Gulf, where the sea ice condition is most severe in the Bohai Sea. The accurate, successive and long-periodic real time observation of sea ice parameters is necessary for the investigation of sea ice thermodynamics and dynamics, and also guarantees the safety in an oil/gas exploitation. A sea ice radar observation system is set up on the JZ20-2 oil/gas platform according to the sea ice characteristics and engineering requirement of the Liaodong Gulf. A digital image processing and analyzing system for sea ice radar observation data is developed to extract sea ice concentration, ice velocity and ice floe area. The sea ice conditions in the JZ20-2 oil field are monitored and analyzed with this radar observation system and digital image processing software during the winter of 2011-2012. Especially, the field distribution of the sea ice velocity and the mean ice velocity in 48 h are analyzed. The results provide real time sea ice information for the sea ice management in the oil/gas field, and the investigation of sea ice drifting. Some open problems and improvements for the sea-ice radar observation and the digital image processing system are discussed.
Sea ice brings negative influences on offshore structures, nautical transportation and aquaculture in the Liaodong Gulf, where the sea ice condition is most severe in the Bohai Sea. The accurate, successive and long-periodic real time observation of sea ice parameters is necessary for the investigation of sea ice thermodynamics and dynamics, and also guarantees the safety in an oil/gas exploitation. A sea ice radar observation system is set up on the JZ20-2 oil/gas platform according to the sea ice characteristics and engineering requirement of the Liaodong Gulf. A digital image processing and analyzing system for sea ice radar observation data is developed to extract sea ice concentration, ice velocity and ice floe area. The sea ice conditions in the JZ20-2 oil field are monitored and analyzed with this radar observation system and digital image processing software during the winter of 2011-2012. Especially, the field distribution of the sea ice velocity and the mean ice velocity in 48 h are analyzed. The results provide real time sea ice information for the sea ice management in the oil/gas field, and the investigation of sea ice drifting. Some open problems and improvements for the sea-ice radar observation and the digital image processing system are discussed.
2013, 35(3): 128-136.
doi: 10.3969/j.issn.0253-4193.2013.03.015
Abstract:
The spatial distribution of nutrients structure and its controlling factors indicated by the dissolved inorganic nitrogen(DIN=NO3-+NO2-+NH4+),PO43-,SiO32- were studied on the basis of four cruises in the Changjiang (Yangtze River) Estuary and the adjacent East China Sea(ECS), nutrients absolute limitation was presented, after that the relative potential limitation was analyzed. The results showed, controlled by the Changjiang dilution water and offshore seawater mixing, DIN/P was usually above 16 in the coast east of 123°E all year round, Si/DIN was below 1 except in autumn, indicating "excess nitrogen" influenced by the Changjiang River dilution water. The water DIN/P were increased and Si/DIN decreased abnormally when phytoplankton bloomed in the riverine plume area (31°~32.5°N,122.5°~124°E)in spring and summer. In autumn DIN/P was low west and high east and Si/DIN was high west and low east in the north estuary, because high DIN low PO43- Changjiang River dilution water was separated by relatively low DIN and high SiO32- Subei Coastal Water coming from the north. In winter the oligotrophic Kuroshio water intrudes deeply into the ECS continental shelf, the high DIN/P and low Si/DIN area was attributed to elevated DIN resulting from northeast transporting Changjiang Dilution Water and enhanced Subei Coastal Water. The relative potential nutrients limitation was discriminated based on Redfield ratio: The coastal area west of 123°E presented PO43- potential limitation under the influence of Changjiang Dilution Water with high DIN and SiO32- all year round, while regional PO43- absolute limitation and relative potential limitation occurred in spring and summer as a result of massive PO43- uptake by phytoplankton. N limitation stations (DIN relative potential limitation) scattered offshore in spring and summer. In autumn N limitation existed in north coastal area as well as offshore stations. Strengthened intrusion of KSW (Kuroshio Surface Water) with lower DIN/P caused more N limitation stations in winter. The estuary plume area showed Si limitation (SiO32- relative potential limitation) because of diatom blooms in summer, whereas in winter Si limitation existed in most southern offshore stations, indicating SiO32- relative deficit in KSW.
The spatial distribution of nutrients structure and its controlling factors indicated by the dissolved inorganic nitrogen(DIN=NO3-+NO2-+NH4+),PO43-,SiO32- were studied on the basis of four cruises in the Changjiang (Yangtze River) Estuary and the adjacent East China Sea(ECS), nutrients absolute limitation was presented, after that the relative potential limitation was analyzed. The results showed, controlled by the Changjiang dilution water and offshore seawater mixing, DIN/P was usually above 16 in the coast east of 123°E all year round, Si/DIN was below 1 except in autumn, indicating "excess nitrogen" influenced by the Changjiang River dilution water. The water DIN/P were increased and Si/DIN decreased abnormally when phytoplankton bloomed in the riverine plume area (31°~32.5°N,122.5°~124°E)in spring and summer. In autumn DIN/P was low west and high east and Si/DIN was high west and low east in the north estuary, because high DIN low PO43- Changjiang River dilution water was separated by relatively low DIN and high SiO32- Subei Coastal Water coming from the north. In winter the oligotrophic Kuroshio water intrudes deeply into the ECS continental shelf, the high DIN/P and low Si/DIN area was attributed to elevated DIN resulting from northeast transporting Changjiang Dilution Water and enhanced Subei Coastal Water. The relative potential nutrients limitation was discriminated based on Redfield ratio: The coastal area west of 123°E presented PO43- potential limitation under the influence of Changjiang Dilution Water with high DIN and SiO32- all year round, while regional PO43- absolute limitation and relative potential limitation occurred in spring and summer as a result of massive PO43- uptake by phytoplankton. N limitation stations (DIN relative potential limitation) scattered offshore in spring and summer. In autumn N limitation existed in north coastal area as well as offshore stations. Strengthened intrusion of KSW (Kuroshio Surface Water) with lower DIN/P caused more N limitation stations in winter. The estuary plume area showed Si limitation (SiO32- relative potential limitation) because of diatom blooms in summer, whereas in winter Si limitation existed in most southern offshore stations, indicating SiO32- relative deficit in KSW.
2013, 35(3): 137-146.
doi: 10.3969/j.issn.0253-4193.2013.03.016
Abstract:
The cadmium toxicity data of indigenous marine species were collected and screened on the basis of analyzing the characteristics of marine biota in China.Marine water quality criteria (WQC) of Cd were then derived using the species sensitivity distribution (SSD) approach with different regression models.The results indicated that the Burr Ⅲ model was better for fitting the SSD than the other four models, log-logistic, log-normal, Gumbel and Weibull.The acute and chronic marine WQC derived with Burr Ⅲ model were 63.0 μg/L and 8.0 μg/L, respectively.The feasibility of incorporating freshwater toxicity data to derive the Cd WQC was explored.It was shown that this kind of introduction derived a rather conservative marine WQC f and thus led to an "over-protection" for marine organisms.The ecological risk of Cd was preliminarily evaluated by comparing the chronic WQC value with measured ambient waterborne Cd concentrations.It was found that there existed a low ecological risk to marine biota in China coastal waters.
The cadmium toxicity data of indigenous marine species were collected and screened on the basis of analyzing the characteristics of marine biota in China.Marine water quality criteria (WQC) of Cd were then derived using the species sensitivity distribution (SSD) approach with different regression models.The results indicated that the Burr Ⅲ model was better for fitting the SSD than the other four models, log-logistic, log-normal, Gumbel and Weibull.The acute and chronic marine WQC derived with Burr Ⅲ model were 63.0 μg/L and 8.0 μg/L, respectively.The feasibility of incorporating freshwater toxicity data to derive the Cd WQC was explored.It was shown that this kind of introduction derived a rather conservative marine WQC f and thus led to an "over-protection" for marine organisms.The ecological risk of Cd was preliminarily evaluated by comparing the chronic WQC value with measured ambient waterborne Cd concentrations.It was found that there existed a low ecological risk to marine biota in China coastal waters.
2013, 35(3): 147-154.
doi: 10.3969/j.issn.0253-4193.2013.03.017
Abstract:
Terrestrial dissolved organic matter (DOM) exported from mangrove comprises an important fraction of terrestrial DOM in the ocean. The study of photo-and bio-degradation of mangrove DOM can help better understanding the fate of mangrove DOM and the role of mangrove DOM in the coastal biogeochemical cycle. Therefore, mangrove pore-water samples were collected in April 2010 to perform the photo-and bio-degradation of mangrove DOM. Dissolved organic carbon (DOC), density of bacteria and dissolved lignin phenols were measured in light(photo-degradation) and dark incubation (bio-degradation), respectively. The results showed that after 128 d dark incubation, DOC decreased from 2 216 μmol/L to 718 μmol/L, indicating that the bioavailability of mangrove pore-water DOC was approximately 70%; after 11 days exposure to the natural sunlight, DOC decreased from 2216 μmol/L to 800 μmol/L. The degradation rates of lignin phenols were much higher in light incubation(-0.132 d-1) than dark incubation(-0.008 d-1).During the light incubation, the degradation rates of lignin phenols were higher than DOC. The rates of photo-degradation of lignin phenols were different among different lignin groups, with the increase of sunlight exposure, the ratio of syringyl (S) phenols to vanillyl (V) phenols decreased and the ratio of vanillic acid to vanillin (Ad/Al)v increased. The comparison of the variations of DOC and lignin phenols during photo-and bio-degradation suggested that microbial consumption was the major factor for the removal of mangrove DOC and photo-degradation was the major factor for the removal of terrestrial DOM in water column. The comparison of the variations of bacteria during photo-and bio-degradation implied that light can improve the utilization of DOC by bacteria. The degradation rate of lignin in mangrove forest was close to Congo River sample, but higher than that of Mississippi River samples. However, the trends of S/V and (Ad/Al)v were similar as other regions.
Terrestrial dissolved organic matter (DOM) exported from mangrove comprises an important fraction of terrestrial DOM in the ocean. The study of photo-and bio-degradation of mangrove DOM can help better understanding the fate of mangrove DOM and the role of mangrove DOM in the coastal biogeochemical cycle. Therefore, mangrove pore-water samples were collected in April 2010 to perform the photo-and bio-degradation of mangrove DOM. Dissolved organic carbon (DOC), density of bacteria and dissolved lignin phenols were measured in light(photo-degradation) and dark incubation (bio-degradation), respectively. The results showed that after 128 d dark incubation, DOC decreased from 2 216 μmol/L to 718 μmol/L, indicating that the bioavailability of mangrove pore-water DOC was approximately 70%; after 11 days exposure to the natural sunlight, DOC decreased from 2216 μmol/L to 800 μmol/L. The degradation rates of lignin phenols were much higher in light incubation(-0.132 d-1) than dark incubation(-0.008 d-1).During the light incubation, the degradation rates of lignin phenols were higher than DOC. The rates of photo-degradation of lignin phenols were different among different lignin groups, with the increase of sunlight exposure, the ratio of syringyl (S) phenols to vanillyl (V) phenols decreased and the ratio of vanillic acid to vanillin (Ad/Al)v increased. The comparison of the variations of DOC and lignin phenols during photo-and bio-degradation suggested that microbial consumption was the major factor for the removal of mangrove DOC and photo-degradation was the major factor for the removal of terrestrial DOM in water column. The comparison of the variations of bacteria during photo-and bio-degradation implied that light can improve the utilization of DOC by bacteria. The degradation rate of lignin in mangrove forest was close to Congo River sample, but higher than that of Mississippi River samples. However, the trends of S/V and (Ad/Al)v were similar as other regions.
2013, 35(3): 155-165.
doi: 10.3969/j.issn.0253-4193.2013.03.018
Abstract:
Integrated Biomarker Response (IBR) index was used for accessing the integrated quality impacted by four organic contaminants, total petroleum hydrocarbon (TPH), polychlorinated biphenyls (PCBs), Nonylphenol (NP) and Benzo(a)pyrene (B[a]P) in the intertidal sediment of Beibu Bay. Bivalves Paphia undulata and sediments were collected from 9 sites. Contents of the organic contaminants were analyzed in the sediment and soft tissue samples. Seven biomarkers related to cellular defense systems including reduced glutathione (GSH), oxidized glutathione (GSSG), glutathione peroxidase (GPx), catalase (CAT), etc. in the hepatic tissues and gills of bivalves were also quantified respectively. According to correlation analysis, eight biomarkers were selected for calculating IBR value because of their significant response to one or two pollutants in the sediment and bivalve tissues. They were GPx, GSH, GSSG, CAT in the hepatic tissues and GPx, GSH, GSSG, CAT in the gills. The IBR index of 9 sampling sites ranged from 0.27 to 1.48. Higher IBR values at site S4 in the western Fangchenggang Bay and S9 in Laorensha tidal-flat of Qinzhou Bay indicated a situation of oxidative stress in bivalves induced by organic pollutants. on the contrary, site S2 in Lemin Port and S3 in Jianghong Port of Zhanjiang City had lower IBR values indicating little pollution situation. The IBR index data agreed with chemical determination profiles and distribution of contamination sources. Therefore, this method will offer a promising potential for the integrated assessment of organic contamination in intertidal sediment of Beibu Gulf.
Integrated Biomarker Response (IBR) index was used for accessing the integrated quality impacted by four organic contaminants, total petroleum hydrocarbon (TPH), polychlorinated biphenyls (PCBs), Nonylphenol (NP) and Benzo(a)pyrene (B[a]P) in the intertidal sediment of Beibu Bay. Bivalves Paphia undulata and sediments were collected from 9 sites. Contents of the organic contaminants were analyzed in the sediment and soft tissue samples. Seven biomarkers related to cellular defense systems including reduced glutathione (GSH), oxidized glutathione (GSSG), glutathione peroxidase (GPx), catalase (CAT), etc. in the hepatic tissues and gills of bivalves were also quantified respectively. According to correlation analysis, eight biomarkers were selected for calculating IBR value because of their significant response to one or two pollutants in the sediment and bivalve tissues. They were GPx, GSH, GSSG, CAT in the hepatic tissues and GPx, GSH, GSSG, CAT in the gills. The IBR index of 9 sampling sites ranged from 0.27 to 1.48. Higher IBR values at site S4 in the western Fangchenggang Bay and S9 in Laorensha tidal-flat of Qinzhou Bay indicated a situation of oxidative stress in bivalves induced by organic pollutants. on the contrary, site S2 in Lemin Port and S3 in Jianghong Port of Zhanjiang City had lower IBR values indicating little pollution situation. The IBR index data agreed with chemical determination profiles and distribution of contamination sources. Therefore, this method will offer a promising potential for the integrated assessment of organic contamination in intertidal sediment of Beibu Gulf.
2013, 35(3): 166-171.
doi: 10.3969/j.issn.0253-4193.2013.03.019
Abstract:
Based on the sound speeds of seafloor sediments measured in-situ in the middle area of the southern Huanghai Sea, the correlations between the in-situ sound speeds and the physical parameters of seafloor sediments such as density, moisture content, porosity ratio and percent porosity are analyzed.The predicting equations of the in-situ sound speeds are established by means of a regression analysis.The result shows that there are good correlations between the in-situ sound speeds and the physical parameters with the coefficients r>0.95.The comparison between the predicting equations of the in situ sound speeds and those established based on the sound speeds measured in laboratory on board indicates that their average deviation is 22.6 m/s with a minimum of 15.8 m/s and a maximum of 31.3 m/s.The comparison between the predicting equations of the in-situ sound speeds and those developed by other authors demonstrates a distinct difference among the different predicting equations of sound speeds, and the reasons are discussed
Based on the sound speeds of seafloor sediments measured in-situ in the middle area of the southern Huanghai Sea, the correlations between the in-situ sound speeds and the physical parameters of seafloor sediments such as density, moisture content, porosity ratio and percent porosity are analyzed.The predicting equations of the in-situ sound speeds are established by means of a regression analysis.The result shows that there are good correlations between the in-situ sound speeds and the physical parameters with the coefficients r>0.95.The comparison between the predicting equations of the in situ sound speeds and those established based on the sound speeds measured in laboratory on board indicates that their average deviation is 22.6 m/s with a minimum of 15.8 m/s and a maximum of 31.3 m/s.The comparison between the predicting equations of the in-situ sound speeds and those developed by other authors demonstrates a distinct difference among the different predicting equations of sound speeds, and the reasons are discussed
2013, 35(3): 172-178.
doi: 10.3969/j.issn.0253-4193.2013.03.020
Abstract:
On the basis of the grain size analysis of surface sediment samples collected from Lianyungang coastal waters in winter and summer respectively,sediment transport trends are studied using the method of Gisedtrend,and influence factors are also discussed. The results show that the sediment transport trends in Lianyungang coastal waters are obvious. The sediment transport trends in the Haizhou Bay are southwest ward,which is consistent with the silting on the top of the bay. The sediment transport trends south of the port area are convergent. A characteristic distance,a sampling grid,a surrounding environment,and grain size fractions have a direct effect on a grain size trend analysis. Taking into account the influence of coastline,island,artificial boundary as well as the grain size fractions can enhance the reasonability of the grain size trend analysis.
On the basis of the grain size analysis of surface sediment samples collected from Lianyungang coastal waters in winter and summer respectively,sediment transport trends are studied using the method of Gisedtrend,and influence factors are also discussed. The results show that the sediment transport trends in Lianyungang coastal waters are obvious. The sediment transport trends in the Haizhou Bay are southwest ward,which is consistent with the silting on the top of the bay. The sediment transport trends south of the port area are convergent. A characteristic distance,a sampling grid,a surrounding environment,and grain size fractions have a direct effect on a grain size trend analysis. Taking into account the influence of coastline,island,artificial boundary as well as the grain size fractions can enhance the reasonability of the grain size trend analysis.
2013, 35(3): 179-188.
doi: 10.3969/j.issn.0253-4193.2013.03.021
Abstract:
Grain-size parameters of marine sediments are the sensitive indexes for reflecting the sediment sources and hydrodynamic conditions. At present, the various methods for calculating the grain-size parameters of marine sediments partially restrict the integration and availability of grain-size data. Three hundred and four-eight surface sediments grain-size data from the offshore of the Changjiang River Estuary are used to calculate the grain-size parameters, respectively adopting the graphical method of Folk and Ward, the moment method of Collias et al. and the moment method of McManus. Correlation analysis and statistical analysis methods are employed to detect the differences of results from the above three different methods and their influencing factors. The mean grain-size and sorting coefficient derived from the graphical method and the moment methods are significantly correlative and stable, which are not affected by sediment sources. On the contrary, the values of skewness and kurtosis calculated from three different methods indicate low correlation or even no relativity. The results show that the differences of grain-size parameters calculated from the three methods depend both on sediment types and their form of distribution curve. When sediments components are uniform with a normal frequency curves, there are high correlation coefficients amount the grain-size parameters from different methods, While for the case of the coarse or fine sediments with the abnormal frequency curves of a long tail feature, the different of grain-size parameters using difference methods are increased. The results suggest that Collias et al. moment formulas are recommended to be used in the process of grain-size integration for their sensitivity and reliability in reflecting the grain-size distribution characteristic.
Grain-size parameters of marine sediments are the sensitive indexes for reflecting the sediment sources and hydrodynamic conditions. At present, the various methods for calculating the grain-size parameters of marine sediments partially restrict the integration and availability of grain-size data. Three hundred and four-eight surface sediments grain-size data from the offshore of the Changjiang River Estuary are used to calculate the grain-size parameters, respectively adopting the graphical method of Folk and Ward, the moment method of Collias et al. and the moment method of McManus. Correlation analysis and statistical analysis methods are employed to detect the differences of results from the above three different methods and their influencing factors. The mean grain-size and sorting coefficient derived from the graphical method and the moment methods are significantly correlative and stable, which are not affected by sediment sources. On the contrary, the values of skewness and kurtosis calculated from three different methods indicate low correlation or even no relativity. The results show that the differences of grain-size parameters calculated from the three methods depend both on sediment types and their form of distribution curve. When sediments components are uniform with a normal frequency curves, there are high correlation coefficients amount the grain-size parameters from different methods, While for the case of the coarse or fine sediments with the abnormal frequency curves of a long tail feature, the different of grain-size parameters using difference methods are increased. The results suggest that Collias et al. moment formulas are recommended to be used in the process of grain-size integration for their sensitivity and reliability in reflecting the grain-size distribution characteristic.
2013, 35(3): 189-196.
doi: 10.3969/j.issn.0253-4193.2013.03.022
Abstract:
Based on the restoring coastline position and the underwater topography of the Abandoned Huanghe River Delta coast in different developmental stages, since the Huanghe River turning over to the north,through establishing a wide range tidal wave mathematical model and a partial tidal current mathematical model, the Huanghai Sea tidal current characteristic and the change in different evolution stages of the delta have been studied.The result shows that the current velocity is relatively weak in the radial sand ridges, due to the abandoned Huanghe River coastline protruding more than 20 km, and the ambitious underwater delta, blocking the tidal wave of spread from north to south. With the Jiangsu coastline retreating, the abandoned Huanghe River undersea delta deplanation, revolution tide in the south Huanghai Sea gets strengthening, the average current velocity and the maximum current velocity are expressed as tended to increase in the Xiyang, Lanshayang and Xiaomiaohong waterways in the radial sand ridges.
Based on the restoring coastline position and the underwater topography of the Abandoned Huanghe River Delta coast in different developmental stages, since the Huanghe River turning over to the north,through establishing a wide range tidal wave mathematical model and a partial tidal current mathematical model, the Huanghai Sea tidal current characteristic and the change in different evolution stages of the delta have been studied.The result shows that the current velocity is relatively weak in the radial sand ridges, due to the abandoned Huanghe River coastline protruding more than 20 km, and the ambitious underwater delta, blocking the tidal wave of spread from north to south. With the Jiangsu coastline retreating, the abandoned Huanghe River undersea delta deplanation, revolution tide in the south Huanghai Sea gets strengthening, the average current velocity and the maximum current velocity are expressed as tended to increase in the Xiyang, Lanshayang and Xiaomiaohong waterways in the radial sand ridges.
2013, 35(3): 197-203.
doi: 10.3969/j.issn.0253-4193.2013.03.023
Abstract:
Brown tide is a type of harmful algal bloom caused by picoplanktonic algae. It has occured continuously since 2009 and caused significant economic losses in the Bohai Sea. Controlling and reducing detrimental environmental and economic losses in affected ecosystems become an urgent problem in situations where accurate prevention and pre-control systems are not available. Mitigation of HABs by clays is an important and widely used control method. A variety of original clays and modified clays were tested on the brown tide species-Aureococcus anophagef ferens and five typical clays were chosen as the main experimental material. A series of experiments that employed original and modified clays to remove Aureococcus anophagef ferens were tested. The results showed that removal efficiency of Aureococcus blooms may be limited due to their small size and cellular density. The removal efficiency varied with the type of clay and kaolinite indicated better removal ability as compared to montmorillonite. After modification, all clay types showed significant improvement with more than three folds in removal rates. Additionally, application procedures that increase the concentration of original and modified clays, select the appropriate clay particle size and use fresh water as dispersion medium would achieve higher cell removal efficiency. Overall, our study laid a foundation for further research into the more efficient, environmentally removal materials and technologies that can be used as emergency control strategies for brown tide in coastal waters.
Brown tide is a type of harmful algal bloom caused by picoplanktonic algae. It has occured continuously since 2009 and caused significant economic losses in the Bohai Sea. Controlling and reducing detrimental environmental and economic losses in affected ecosystems become an urgent problem in situations where accurate prevention and pre-control systems are not available. Mitigation of HABs by clays is an important and widely used control method. A variety of original clays and modified clays were tested on the brown tide species-Aureococcus anophagef ferens and five typical clays were chosen as the main experimental material. A series of experiments that employed original and modified clays to remove Aureococcus anophagef ferens were tested. The results showed that removal efficiency of Aureococcus blooms may be limited due to their small size and cellular density. The removal efficiency varied with the type of clay and kaolinite indicated better removal ability as compared to montmorillonite. After modification, all clay types showed significant improvement with more than three folds in removal rates. Additionally, application procedures that increase the concentration of original and modified clays, select the appropriate clay particle size and use fresh water as dispersion medium would achieve higher cell removal efficiency. Overall, our study laid a foundation for further research into the more efficient, environmentally removal materials and technologies that can be used as emergency control strategies for brown tide in coastal waters.
2013, 35(3): 204-214.
doi: 10.3969/j.issn.0253-4193.2013.03.024
Abstract:
Mitochondrial DNA of Zhangzhou Coelomactra antiquata was obtained by long PCR amplification, and sequenced using primers-walking strategy. Then the phylogenetic tree was built with 49 bivalve species to explore the evolutionary status of the Zhangzhou C. antiquata. The results showed that the total length of mitochondrial genome of Zhangzhou C. antiquata is 17 199 bp and A+T content is 64.2%. Thirty-six genes encoding on the same chain were consisted of 12 protein genes, 22 tRNA (one duplication of tRNASer, and two copies of tRNAMet) genes and two rRNA genes (lrRNA and srRNA). The nucleotide content of non-coding regions is 10.4% (1 842 bp/17 199 bp), one major non-coding region (MNR) is 882 bp, another 400nt non-coding region, which is specific for ZZ C. antiquata, was also found in its mitochondrial genome. Significant differences of MNR between Zhangzhou C. antiquata and Rizhao C. antiquata were observed. As references to three species from Meretrix(Veneroida), four species from Mytilus(Mytiloida), and six species from Crassostrea(Ptenioida), the differences of nucleotides and amino acid sequences of protein coding genes revealed that divergence of Zhangzhou C. antiquata and Rizhao C. antiquata reached the level of interspecies difference. The difference of the encoding genes, tRNA composition and the non-coding regions suggest that Zhangzhou C. antiquata should be a new species of genus Coelomactra.
Mitochondrial DNA of Zhangzhou Coelomactra antiquata was obtained by long PCR amplification, and sequenced using primers-walking strategy. Then the phylogenetic tree was built with 49 bivalve species to explore the evolutionary status of the Zhangzhou C. antiquata. The results showed that the total length of mitochondrial genome of Zhangzhou C. antiquata is 17 199 bp and A+T content is 64.2%. Thirty-six genes encoding on the same chain were consisted of 12 protein genes, 22 tRNA (one duplication of tRNASer, and two copies of tRNAMet) genes and two rRNA genes (lrRNA and srRNA). The nucleotide content of non-coding regions is 10.4% (1 842 bp/17 199 bp), one major non-coding region (MNR) is 882 bp, another 400nt non-coding region, which is specific for ZZ C. antiquata, was also found in its mitochondrial genome. Significant differences of MNR between Zhangzhou C. antiquata and Rizhao C. antiquata were observed. As references to three species from Meretrix(Veneroida), four species from Mytilus(Mytiloida), and six species from Crassostrea(Ptenioida), the differences of nucleotides and amino acid sequences of protein coding genes revealed that divergence of Zhangzhou C. antiquata and Rizhao C. antiquata reached the level of interspecies difference. The difference of the encoding genes, tRNA composition and the non-coding regions suggest that Zhangzhou C. antiquata should be a new species of genus Coelomactra.
2013, 35(3): 215-224.
doi: 10.3969/j.issn.0253-4193.2013.03.025
Abstract:
We investigated the abundance and biomass of planktonic ciliates in Sanggou Bay, Huanghai Sea during 4 cruises between April 2011 and January 2012. The average abundance of ciliates was (7 552±10 979) ind/L, ranging from 408 ind/L to 61667 ind/L. The average biomass of ciliates(C) was( 4.79±5.77) μg/L, ranging from 0.35 μg/L to 33.09 μg/L. Abundance and biomss of aloricate ciliates decreased from the inner part to the outer part of Sanggou Bay. Tintinnids had a seaward distribution, tending to concentrate in the regions with higher salinity. High value area of total ciliate abundance and biomass moved clockwise seasonally. Ciliate abundance was highest in spring and lowest in winter. Ciliate biomass was highest in summer and lowest in winter. Larger aloricate ciliate species were more prevalent in summer, while smaller species increased their proportion of total abundance in winter. Average lorica oral diameter of tintinnids was larger in summer and smaller in autumn. Twenty seven tintinnid species were identified, 13 of which were in genus Tintinnopsis. Tintinnids occupied 16.3%±21.9% of the total ciliate abundance, being highest in summer and lowest in winter. Ciliate abundance showed no correlation with temperature, salinity, Chl a concentration and picoeukaryotes abundance, however, it showed significant positive correlations with abundance of Synechococcus and heterotrophic bacteria.
We investigated the abundance and biomass of planktonic ciliates in Sanggou Bay, Huanghai Sea during 4 cruises between April 2011 and January 2012. The average abundance of ciliates was (7 552±10 979) ind/L, ranging from 408 ind/L to 61667 ind/L. The average biomass of ciliates(C) was( 4.79±5.77) μg/L, ranging from 0.35 μg/L to 33.09 μg/L. Abundance and biomss of aloricate ciliates decreased from the inner part to the outer part of Sanggou Bay. Tintinnids had a seaward distribution, tending to concentrate in the regions with higher salinity. High value area of total ciliate abundance and biomass moved clockwise seasonally. Ciliate abundance was highest in spring and lowest in winter. Ciliate biomass was highest in summer and lowest in winter. Larger aloricate ciliate species were more prevalent in summer, while smaller species increased their proportion of total abundance in winter. Average lorica oral diameter of tintinnids was larger in summer and smaller in autumn. Twenty seven tintinnid species were identified, 13 of which were in genus Tintinnopsis. Tintinnids occupied 16.3%±21.9% of the total ciliate abundance, being highest in summer and lowest in winter. Ciliate abundance showed no correlation with temperature, salinity, Chl a concentration and picoeukaryotes abundance, however, it showed significant positive correlations with abundance of Synechococcus and heterotrophic bacteria.
2013, 35(3): 225-238.
doi: 10.3969/j.issn.0253-4193.2013.03.026
Abstract:
Abundance, biomass and size structrue of heterotrophic nanoflagellates (HNF) were investigated in the northern South China Sea (NSCS) during four cruises in summer (July 20-August 16, 2009), winter (January 6-30, 2010), autumn (October 26-November 24, 2010) and spring (April 30-May 24, 2011), respectively.It was shown that the abundance and biomass of HNF in spring, summer, autumn, winter were (0.05-1.93)×103, (0.03-2.65)×103, (0.09-2.05)×103, (0.04-1.84)×103 cells/mL and 0.56-19.50, 0.04-24.11, 0.96-14.80, 0.29-22.26 μg/L, respectively.HNF in the 2-5 μm size fraction dominated the HNF community, which accounted for more than 65% of total HNF abundance in the four seasons, while HNF in the 10-20 μm size class constituted less than 10% of total HNF abundance.In horizontal distribution, the abundance of HNF decreased gradually with distance from the coast to the open sea.In vertical distribution, the abundance of HNF decreased gradually with the increasing water depth, however, the highest abundance of HNF was observed in DCM layer in summer.Distribution of HNF in NSCS was affected by multiple environmental factors.The seasonal patterns in regulatory regime (top-down vs bottom-up) of HNF were various: during spring and autumn HNF abundance was mainly controled by predator(top-down) factors; during summer HNF abundance was mainly controled by resources(bottom-up); during winter the dominant pattern was undefined.
Abundance, biomass and size structrue of heterotrophic nanoflagellates (HNF) were investigated in the northern South China Sea (NSCS) during four cruises in summer (July 20-August 16, 2009), winter (January 6-30, 2010), autumn (October 26-November 24, 2010) and spring (April 30-May 24, 2011), respectively.It was shown that the abundance and biomass of HNF in spring, summer, autumn, winter were (0.05-1.93)×103, (0.03-2.65)×103, (0.09-2.05)×103, (0.04-1.84)×103 cells/mL and 0.56-19.50, 0.04-24.11, 0.96-14.80, 0.29-22.26 μg/L, respectively.HNF in the 2-5 μm size fraction dominated the HNF community, which accounted for more than 65% of total HNF abundance in the four seasons, while HNF in the 10-20 μm size class constituted less than 10% of total HNF abundance.In horizontal distribution, the abundance of HNF decreased gradually with distance from the coast to the open sea.In vertical distribution, the abundance of HNF decreased gradually with the increasing water depth, however, the highest abundance of HNF was observed in DCM layer in summer.Distribution of HNF in NSCS was affected by multiple environmental factors.The seasonal patterns in regulatory regime (top-down vs bottom-up) of HNF were various: during spring and autumn HNF abundance was mainly controled by predator(top-down) factors; during summer HNF abundance was mainly controled by resources(bottom-up); during winter the dominant pattern was undefined.
2013, 35(3): 239-245.
doi: 10.3969/j.issn.0253-4193.2013.03.027
Abstract:
It is generally recognized that plant rhizosphere microbial biomass is higher than that of non-rhizosphere, and this is related to a variety of substances which secreted by plant roots. Different species of mangrove plant had different degree of eutrophication and with higher phytoplankton biomass, and this was estimated at least to be partly related with the mangrove plant root exudates (REs) and the control effect on the forest organisms. Mangrove plant root exudates are one of the key factors in modulating mangrove ecological effects. Azelaic acid is a kind of two carboxylic acids detected in mangrove plants root exudates for the first time. The preliminary indoor mechanism experiment of the effect of mangrove plant root exudates on algae was conducted by using azelaic acid and alga Prorocentrum micans, the alga was cultivated with different concentrations of azelaic acid. Algal density, shape, intracellular glycerol content, pigment content and other indexes were detected in the algal growth period. The main results are as follows: in low concentration of 0.5-1.5 mg/L, azelaic acid could be used as the nutrients to be absorbed by the algal cells. While at a higher concentration of 2 mg/L and 4 mg/L, azelaic acid mainly expressed as allelopathic inhibition. Cell membrane lipid peroxidation lead to intracellular glycerol content increased, Chromatoplast produced strong stress response, the pigment synthesis was increased, especially peridinin content. More intracellular substances produced through cell metabolisms, such as starch and lipid droplets, and resulting in enlargement of vacuoles. Chromatoplast is one of the most important organelle to response stress and to resist adversity. The ecological effect of azelaic acid was mainly classified to allelopathy as for its low concentration and higher inhibition effect. Mangrove plant root exudates has a regulatory role on forest ecology. In situ field test on the mixed effects of mangrove plant root exudates should be strengthened in the future.
It is generally recognized that plant rhizosphere microbial biomass is higher than that of non-rhizosphere, and this is related to a variety of substances which secreted by plant roots. Different species of mangrove plant had different degree of eutrophication and with higher phytoplankton biomass, and this was estimated at least to be partly related with the mangrove plant root exudates (REs) and the control effect on the forest organisms. Mangrove plant root exudates are one of the key factors in modulating mangrove ecological effects. Azelaic acid is a kind of two carboxylic acids detected in mangrove plants root exudates for the first time. The preliminary indoor mechanism experiment of the effect of mangrove plant root exudates on algae was conducted by using azelaic acid and alga Prorocentrum micans, the alga was cultivated with different concentrations of azelaic acid. Algal density, shape, intracellular glycerol content, pigment content and other indexes were detected in the algal growth period. The main results are as follows: in low concentration of 0.5-1.5 mg/L, azelaic acid could be used as the nutrients to be absorbed by the algal cells. While at a higher concentration of 2 mg/L and 4 mg/L, azelaic acid mainly expressed as allelopathic inhibition. Cell membrane lipid peroxidation lead to intracellular glycerol content increased, Chromatoplast produced strong stress response, the pigment synthesis was increased, especially peridinin content. More intracellular substances produced through cell metabolisms, such as starch and lipid droplets, and resulting in enlargement of vacuoles. Chromatoplast is one of the most important organelle to response stress and to resist adversity. The ecological effect of azelaic acid was mainly classified to allelopathy as for its low concentration and higher inhibition effect. Mangrove plant root exudates has a regulatory role on forest ecology. In situ field test on the mixed effects of mangrove plant root exudates should be strengthened in the future.
2013, 35(3): 246-254.
doi: 10.3969/j.issn.0253-4193.2013.03.028
Abstract:
Bulk and grain size content, δ18O and δ13C values of carbonates in the surface sediments collected from the Zhujiang Estuary, shelf, slope and basin of the northern South China Sea were analyzed in order to determine the source of carbonates and the controlling factors of δ18O and δ13C of carbonates. The results show that the carbonates in the surface sediments of the northern South China Sea are mainly authigenic. The carbonate contents of the slope are obviously larger than those of the Zhujiang Estuary, shelf and basin. In the Zhujiang Estuary with water depth of 34 m and the basin with water depth of more than 730 m, 76.9%~84.5% of carbonates are distributed in the particles which grain diameter is less than 32 μm. Correspondingly, in the shelf with water depth of 80 m and the slope with water depth of 550 m, the carbonates are evenly distributed among all grain sizes. In addition, the spatial and grain size distribution of δ18O and δ13C of the carbonates in the Zhujiang Estuary and the shelf are obviously different from those in the slope and the basin. In the Zhujiang Estuary and the shelf, the bulk δ18O and δ13C values of carbonates become heavy from the Zhujiang Estuary to the shelf; the grain size distribution of δ18O and δ13C values of carbonates are that the δ18O and δ13C values of carbonates become heavy with the increasing of grain size and the δ18O values are positively related to δ13C values; indicating that the δ18O and δ13C of carbonates in the Zhujiang Estuary and the shelf are mainly controlled by δ18O and δ13CDIC of the water from the Zhujiang River. In the slope and the basin, the bulk δ18O values of carbonates become light from the slope to the basin and the bulk δ13C values of carbonates do not have an obviously variation from the slope to the basin; the grain size distribution of δ18O and δ13C values of carbonates are that the δ18O and δ13C values of carbonates do not have a clear trend with the increasing of grain size and the δ18O values are not or negatively related to δ13C values; indicating that the δ18O of carbonates are mainly controlled by surface seawater temperature and the δ13C of carbonates are mainly controlled by the δ13CDIC of surrounding seawater in the slope and the basin.
Bulk and grain size content, δ18O and δ13C values of carbonates in the surface sediments collected from the Zhujiang Estuary, shelf, slope and basin of the northern South China Sea were analyzed in order to determine the source of carbonates and the controlling factors of δ18O and δ13C of carbonates. The results show that the carbonates in the surface sediments of the northern South China Sea are mainly authigenic. The carbonate contents of the slope are obviously larger than those of the Zhujiang Estuary, shelf and basin. In the Zhujiang Estuary with water depth of 34 m and the basin with water depth of more than 730 m, 76.9%~84.5% of carbonates are distributed in the particles which grain diameter is less than 32 μm. Correspondingly, in the shelf with water depth of 80 m and the slope with water depth of 550 m, the carbonates are evenly distributed among all grain sizes. In addition, the spatial and grain size distribution of δ18O and δ13C of the carbonates in the Zhujiang Estuary and the shelf are obviously different from those in the slope and the basin. In the Zhujiang Estuary and the shelf, the bulk δ18O and δ13C values of carbonates become heavy from the Zhujiang Estuary to the shelf; the grain size distribution of δ18O and δ13C values of carbonates are that the δ18O and δ13C values of carbonates become heavy with the increasing of grain size and the δ18O values are positively related to δ13C values; indicating that the δ18O and δ13C of carbonates in the Zhujiang Estuary and the shelf are mainly controlled by δ18O and δ13CDIC of the water from the Zhujiang River. In the slope and the basin, the bulk δ18O values of carbonates become light from the slope to the basin and the bulk δ13C values of carbonates do not have an obviously variation from the slope to the basin; the grain size distribution of δ18O and δ13C values of carbonates are that the δ18O and δ13C values of carbonates do not have a clear trend with the increasing of grain size and the δ18O values are not or negatively related to δ13C values; indicating that the δ18O of carbonates are mainly controlled by surface seawater temperature and the δ13C of carbonates are mainly controlled by the δ13CDIC of surrounding seawater in the slope and the basin.
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