2013 Vol. 32, No. 9
Display Method:
2013, 32(9): .
Abstract:
Acta Oceanologica Sinica (AOS) is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.
Acta Oceanologica Sinica (AOS) is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.
2013, 32(9): 1-0.
Abstract:
Acta Oceanologica Sinica (AOS) is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.
Acta Oceanologica Sinica (AOS) is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.
2013, 32(9): 1-10.
doi: 10.1007/s13131-013-0346-9
Abstract:
The Yellow Sea Cold Water Mass (YSCWM) is one of the important water mass in the Yellow Sea (YS). It is distributed in the lower layer in the Yellow Sea central trough with the temperature less than 10℃ and the salinity lower than 33.0. To underst and the variability of the YSCWM, the hydrographic data obtained in April and August during 2009-2011 are analyzed in the south eastern Yellow Sea. In August 2011, relatively warm and saline water compared with that in 2009 and 2010 was detected in the lower layer in the Yellow Sea central area. Although the typhoon passed before the cruise, the salinity in the Yellow Sea central trough is much higher than the previous season. It means that the saline event cannot be explained by the typhoon but only by the intrusion of saline water during the previous winter. In April 2011, actually, warmand saline water (T >10℃, S >34) was observed in the deepest water depth of the south eastern area of the Yellow Sea. The wind data show that the northerly wind in 2011 winter is stronger than in 2009 and 2010 winter season. The strong northerly wind can trigger the intrusion of warm and saline Yellow Sea Warm Current. Therefore, it is proposed that the strong northerly wind in winter season leads to the intrusion of the Yellow Sea Warm Current into the Yellow Sea central trough and influenced a variability of the YSCWM in summer.
The Yellow Sea Cold Water Mass (YSCWM) is one of the important water mass in the Yellow Sea (YS). It is distributed in the lower layer in the Yellow Sea central trough with the temperature less than 10℃ and the salinity lower than 33.0. To underst and the variability of the YSCWM, the hydrographic data obtained in April and August during 2009-2011 are analyzed in the south eastern Yellow Sea. In August 2011, relatively warm and saline water compared with that in 2009 and 2010 was detected in the lower layer in the Yellow Sea central area. Although the typhoon passed before the cruise, the salinity in the Yellow Sea central trough is much higher than the previous season. It means that the saline event cannot be explained by the typhoon but only by the intrusion of saline water during the previous winter. In April 2011, actually, warmand saline water (T >10℃, S >34) was observed in the deepest water depth of the south eastern area of the Yellow Sea. The wind data show that the northerly wind in 2011 winter is stronger than in 2009 and 2010 winter season. The strong northerly wind can trigger the intrusion of warm and saline Yellow Sea Warm Current. Therefore, it is proposed that the strong northerly wind in winter season leads to the intrusion of the Yellow Sea Warm Current into the Yellow Sea central trough and influenced a variability of the YSCWM in summer.
2013, 32(9): 11-20.
doi: 10.1007/s13131-013-0347-8
Abstract:
Using a simple damped slab model, it was possible to show that a local wind induced 88% (15 of 17) of the near-inertial oscillations (NIO) observed in the mixed layer near the east coast of Korea from 1999 to 2004. The model, however, over estimated the energy level in about two-thirds of the simulated cases, because the slab model was forced with winds whose characteristic period was shorter than the damping time scale of the model at 1.5 d. At the observation site, due to typhoons and orographic effects, high-frequency wind forcing is quite common, as is the overestimation of the energy level in the slab model results. In short, a simple slab model with a damping time-scale of about 1.5 d would be enough to show that the local wind was the main energy source of the near-inertial energy in this area, but the model could not be used to accurately estimate the amount of the work done by the wind to the mixed layer.
Using a simple damped slab model, it was possible to show that a local wind induced 88% (15 of 17) of the near-inertial oscillations (NIO) observed in the mixed layer near the east coast of Korea from 1999 to 2004. The model, however, over estimated the energy level in about two-thirds of the simulated cases, because the slab model was forced with winds whose characteristic period was shorter than the damping time scale of the model at 1.5 d. At the observation site, due to typhoons and orographic effects, high-frequency wind forcing is quite common, as is the overestimation of the energy level in the slab model results. In short, a simple slab model with a damping time-scale of about 1.5 d would be enough to show that the local wind was the main energy source of the near-inertial energy in this area, but the model could not be used to accurately estimate the amount of the work done by the wind to the mixed layer.
2013, 32(9): 21-29.
doi: 10.1007/s13131-013-0348-7
Abstract:
Positive SST anomalies usually appear in remote ocean such as the China seas during an ENSO event. By analyzing the monthly data of HadISST from 1950 to 2007, it shows that the interannual component of SST anomalies peak approximately 10 months after SST anomalies peak in the eastern equatorial Pacific. As the ENSO event progresses, the positive SST anomalies spread throughout the China seas and eastward along the Kuroshio extension. Atmospheric reanalysis data demonstrate that changes in the net surface heat flux entering into the China seas are responsible for the SST variability. During El Niño, the western north Pacific anticyclone is generated, with anomalous southwester lies prevailing along the East Asian coast. This anticyclone reduces themean surface wind speed which decreases the surface heat flux and then increases the SST. The delays between the developing of this anticyclone and the south Indian Ocean anticyclone with approximately 3-6months cause the 2-3 months lag of the surface heat flux between the China seas and the Indian Ocean. The north western Pacific anticyclone is the key process bridging the warming in the eastern equatorial Pacific and that in the China seas.
Positive SST anomalies usually appear in remote ocean such as the China seas during an ENSO event. By analyzing the monthly data of HadISST from 1950 to 2007, it shows that the interannual component of SST anomalies peak approximately 10 months after SST anomalies peak in the eastern equatorial Pacific. As the ENSO event progresses, the positive SST anomalies spread throughout the China seas and eastward along the Kuroshio extension. Atmospheric reanalysis data demonstrate that changes in the net surface heat flux entering into the China seas are responsible for the SST variability. During El Niño, the western north Pacific anticyclone is generated, with anomalous southwester lies prevailing along the East Asian coast. This anticyclone reduces themean surface wind speed which decreases the surface heat flux and then increases the SST. The delays between the developing of this anticyclone and the south Indian Ocean anticyclone with approximately 3-6months cause the 2-3 months lag of the surface heat flux between the China seas and the Indian Ocean. The north western Pacific anticyclone is the key process bridging the warming in the eastern equatorial Pacific and that in the China seas.
2013, 32(9): 30-37.
doi: 10.1007/s13131-013-0349-6
Abstract:
The seasonal variation of mixing layer depth (MLD) in the ocean is determined by a wind stress and a buoyance flux. A South China Sea (SCS) ocean data assimilation system is used to analyze the seasonal cycle of its MLD. It is found that the variability of MLD in the SCS is shallow in summer and deep in winter, as is the case in general. Owing to local atmosphere forcing and ocean dynamics, the seasonal variability shows a regional characteristic in the SCS. In the northern SCS, the MLD is shallow in summer and deep in winter, affected coherently by the wind stress and the buoyance flux. The variation of MLD in the west is close to that in the central SCS, influenced by the advection of strong western boundary currents. The eastern SCS presents an annual cycle, which is deep in summer and shallow in winter, primarily impacted by a heat flux on the air-sea interface. So regional characteristic needs to be cared in the analysis about the MLD of SCS.
The seasonal variation of mixing layer depth (MLD) in the ocean is determined by a wind stress and a buoyance flux. A South China Sea (SCS) ocean data assimilation system is used to analyze the seasonal cycle of its MLD. It is found that the variability of MLD in the SCS is shallow in summer and deep in winter, as is the case in general. Owing to local atmosphere forcing and ocean dynamics, the seasonal variability shows a regional characteristic in the SCS. In the northern SCS, the MLD is shallow in summer and deep in winter, affected coherently by the wind stress and the buoyance flux. The variation of MLD in the west is close to that in the central SCS, influenced by the advection of strong western boundary currents. The eastern SCS presents an annual cycle, which is deep in summer and shallow in winter, primarily impacted by a heat flux on the air-sea interface. So regional characteristic needs to be cared in the analysis about the MLD of SCS.
2013, 32(9): 38-43.
doi: 10.1007/s13131-013-0350-0
Abstract:
Sea-ice concentration is a key item in global climate change research. Recent progress in remotely sensed sea-ice concentration product has been stimulated by the use of a new sensor, advanced microwave scanning radiometer for EOS (AMSR-E), which offers a spatial resolution of 6 km×4 km at 89GHz. A new inversion algorithm named LASI (linear ASI) using AMSR-E 89GHz data was proposed and applied in the antarctic sea areas. And then comparisons between the LASI ice concentration products and those retrieved by the other two standard algorithms, ASI (arctic radiation and turbulence interaction study sea-ice algorithm) and bootstrap, were made. Both the spatial and temporal variability patterns of ice concentration differences, LASI minus ASI and LASI minus bootstrap, were investigated. Comparative data suggest a high result consistency, especially between LASI and ASI. On the other hand, in order to estimate the LASI ice concentration errors introduced by the tie-points uncertainties, a sensitivity analysis was carried out. Additionally an LASI algorithmerror estimation based on the field measurements was also completed. The errors suggest that themoderate to high ice concentration areas (>70%) are less affected (never exceeding 10%) than those in the low ice concentration. LASI and ASI consume 75 and 112 s respectively when processing the same AMSR-E time series thourghout the year 2010. To conclude, by using the LASI algorithm, not only the seaice concentration can be retrieved with at least an equal quality as that of the two extensively demonstrated operational algorithms, ASI and bootstrap, but also in a more efficient way than ASI.
Sea-ice concentration is a key item in global climate change research. Recent progress in remotely sensed sea-ice concentration product has been stimulated by the use of a new sensor, advanced microwave scanning radiometer for EOS (AMSR-E), which offers a spatial resolution of 6 km×4 km at 89GHz. A new inversion algorithm named LASI (linear ASI) using AMSR-E 89GHz data was proposed and applied in the antarctic sea areas. And then comparisons between the LASI ice concentration products and those retrieved by the other two standard algorithms, ASI (arctic radiation and turbulence interaction study sea-ice algorithm) and bootstrap, were made. Both the spatial and temporal variability patterns of ice concentration differences, LASI minus ASI and LASI minus bootstrap, were investigated. Comparative data suggest a high result consistency, especially between LASI and ASI. On the other hand, in order to estimate the LASI ice concentration errors introduced by the tie-points uncertainties, a sensitivity analysis was carried out. Additionally an LASI algorithmerror estimation based on the field measurements was also completed. The errors suggest that themoderate to high ice concentration areas (>70%) are less affected (never exceeding 10%) than those in the low ice concentration. LASI and ASI consume 75 and 112 s respectively when processing the same AMSR-E time series thourghout the year 2010. To conclude, by using the LASI algorithm, not only the seaice concentration can be retrieved with at least an equal quality as that of the two extensively demonstrated operational algorithms, ASI and bootstrap, but also in a more efficient way than ASI.
2013, 32(9): 44-49.
doi: 10.1007/s13131-013-0351-z
Abstract:
Using the hydroacousticmethod with a 200 kHz scientific echo sounding system, the diel vertical migration (DVM)of the sound-scatteringlayer (SSL) in the Yellow Sea Bottom Cold Water (YSBCW) of the southeastern Yellow Sea was studied in April (spring) and August (summer) of 2010 and 2011. For each survey, 13-27 hours of acoustic data were continuously collected at a stationary station. The acoustic volume scattering strength (Sv) data were analyzed with temperature profile data. In the spring of both 2010 and 2011, the SSL clearly showed the vertical migration through out the entire water column,moving from the surface layer at night to near the bottom during the day. Conductivity, temperature, and depth data indicated that the entire water column was well mixed with low temperature of about 8℃. However, the SSL showed different patterns in the summers of 2010 and 2011. In the summer of 2010 (≈28℃ at the surface), the SSL migrated to near the bottom during the day, but there were two SSLs above and below the thermocline at depth of 10-30 m at night. In the summer of 2011 (≈20℃ at the surface), the SSL extended throughout the entire water column at night, possibly owing to an abrupt change in sea weather conditions caused by the passage of a Typhoon Muifa over the study area. It was concluded that the DVM patterns in summer in the YSBCW area may be greatly influenced by a strengthened or weakened thermocline.
Using the hydroacousticmethod with a 200 kHz scientific echo sounding system, the diel vertical migration (DVM)of the sound-scatteringlayer (SSL) in the Yellow Sea Bottom Cold Water (YSBCW) of the southeastern Yellow Sea was studied in April (spring) and August (summer) of 2010 and 2011. For each survey, 13-27 hours of acoustic data were continuously collected at a stationary station. The acoustic volume scattering strength (Sv) data were analyzed with temperature profile data. In the spring of both 2010 and 2011, the SSL clearly showed the vertical migration through out the entire water column,moving from the surface layer at night to near the bottom during the day. Conductivity, temperature, and depth data indicated that the entire water column was well mixed with low temperature of about 8℃. However, the SSL showed different patterns in the summers of 2010 and 2011. In the summer of 2010 (≈28℃ at the surface), the SSL migrated to near the bottom during the day, but there were two SSLs above and below the thermocline at depth of 10-30 m at night. In the summer of 2011 (≈20℃ at the surface), the SSL extended throughout the entire water column at night, possibly owing to an abrupt change in sea weather conditions caused by the passage of a Typhoon Muifa over the study area. It was concluded that the DVM patterns in summer in the YSBCW area may be greatly influenced by a strengthened or weakened thermocline.
Down-scaled regional ocean modeling system (ROMS) for high-resolution coastal hydrodynamics in Korea
2013, 32(9): 50-61.
doi: 10.1007/s13131-013-0352-y
Abstract:
A down-scaled operational oceanographic system is developed for the coastal waters of Korea using a regional ocean modeling system (ROMS). The operational oceanographic modeling system consists of atmospheric and hydrodynamic models. The hydrodynamic model, ROMS, is coupled with wave, sediment transport, and water qualitymodules. The system forecasts the predicted results twice a day on a 72 h basis, including sea surface elevation, currents, temperature, salinity, storm surge height, and wave information for the coastal waters of Korea. The predicted results are exported to the web-GIS-based coastal information system for real-time dissemination to the public and validation with real-time monitoring data using visualization technologies. The ROMS is two-way coupledwith a simulatingwaves nearshoremodel, SWAN, for the hydrodynamics and waves, nested with themeteorologicalmodel,WRF, for the atmospheric surface forcing, and externally nested with the eutrophicationmodel, CE-QUAL-ICM, for the water quality. The operational model, ROMS, was calibrated with the tidal surface observed with a tide-gage and verified with current data observed by bottom-mounted ADCP or AWAC near the coastal waters of Korea. To validate the predicted results, we used real-time monitoring data derived from remote buoy system, HF-radar, and geostationary ocean color imager (GOCI). This down-scaled operational coastal forecasting system will be used as a part of the Korea operational oceanographic system(KOOS) with other operational oceanographic systems.
A down-scaled operational oceanographic system is developed for the coastal waters of Korea using a regional ocean modeling system (ROMS). The operational oceanographic modeling system consists of atmospheric and hydrodynamic models. The hydrodynamic model, ROMS, is coupled with wave, sediment transport, and water qualitymodules. The system forecasts the predicted results twice a day on a 72 h basis, including sea surface elevation, currents, temperature, salinity, storm surge height, and wave information for the coastal waters of Korea. The predicted results are exported to the web-GIS-based coastal information system for real-time dissemination to the public and validation with real-time monitoring data using visualization technologies. The ROMS is two-way coupledwith a simulatingwaves nearshoremodel, SWAN, for the hydrodynamics and waves, nested with themeteorologicalmodel,WRF, for the atmospheric surface forcing, and externally nested with the eutrophicationmodel, CE-QUAL-ICM, for the water quality. The operational model, ROMS, was calibrated with the tidal surface observed with a tide-gage and verified with current data observed by bottom-mounted ADCP or AWAC near the coastal waters of Korea. To validate the predicted results, we used real-time monitoring data derived from remote buoy system, HF-radar, and geostationary ocean color imager (GOCI). This down-scaled operational coastal forecasting system will be used as a part of the Korea operational oceanographic system(KOOS) with other operational oceanographic systems.
2013, 32(9): 62-73.
doi: 10.1007/s13131-013-0353-x
Abstract:
Both the level 2.5 Mellor-Yamada turbulence closure scheme (MY) and K-profile parameterization (KPP) are popularly used by the oceanmodeling community. The MY and the KPP are improved through including the non-breaking surface wave-induced vertical mixing (Bv), and the improved schemes were tested by using continuous data at the Papa ocean weather station (OWS) during 1961-1965. The numerical results showed that the Bv can make the temperature simulations fit much better with the continuous data from Papa Station. The two improved schemes overcame the shortcomings of predicting too shallow upper mixed layer depth and consequently overheated sea surface temperature during summertime, which are in fact common problems for all turbulence closure models. Statistical analysis showed that the Bv effectively reduced themean absolute error and root mean square error of the upper layer temperature and increased the correlation coefficient between simulation and the observation. Further more, the performance of verticalmixing induced by shear instability and the Bv is also compared. Both the temperature structure and its seasonal cycle significantly improved by including the Bv, regardless of whether shear instability was included or not, especially for the KPP mixing scheme, which suggested that Bv played a dominant role in the upper ocean where the mean current was relatively weak, such as at Papa Station. These results may provide a clue to improve ocean circulation models.
Both the level 2.5 Mellor-Yamada turbulence closure scheme (MY) and K-profile parameterization (KPP) are popularly used by the oceanmodeling community. The MY and the KPP are improved through including the non-breaking surface wave-induced vertical mixing (Bv), and the improved schemes were tested by using continuous data at the Papa ocean weather station (OWS) during 1961-1965. The numerical results showed that the Bv can make the temperature simulations fit much better with the continuous data from Papa Station. The two improved schemes overcame the shortcomings of predicting too shallow upper mixed layer depth and consequently overheated sea surface temperature during summertime, which are in fact common problems for all turbulence closure models. Statistical analysis showed that the Bv effectively reduced themean absolute error and root mean square error of the upper layer temperature and increased the correlation coefficient between simulation and the observation. Further more, the performance of verticalmixing induced by shear instability and the Bv is also compared. Both the temperature structure and its seasonal cycle significantly improved by including the Bv, regardless of whether shear instability was included or not, especially for the KPP mixing scheme, which suggested that Bv played a dominant role in the upper ocean where the mean current was relatively weak, such as at Papa Station. These results may provide a clue to improve ocean circulation models.
2013, 32(9): 74-81.
doi: 10.1007/s13131-013-0354-9
Abstract:
A standard skill assessment (SA) tool was developed and implemented to evaluate the performance of operational forecast models in the Korea operational oceanographic system. The SA tool provided a robust way to assess model skill in the system by comparing predictions and observations, and involved the computation of multiple skillmetrics including correlation and error skills. User-and system-based acceptance criteria of skill metrics were applied to determine whether predictions were acceptable for the system. To achieve this, the tool produced a time series comparison plot, a skill score table, and an advanced summarized diagram to effectively demonstrate the multiple skill scores. Moreover, the SA was conducted to evaluate both atmospheric and hydrodynamic forecast variables. For the atmospheric variables, acceptable error criteriawere preferable to acceptable correlation criteria over short timescales, since themean square error overwhelmed the observation variance. Conversely, for the hydrodynamic variables, acceptable root mean square percentage error (e.g., perms) criteria were preferable to acceptable error (e.g.,erms) criteria owing to the spatially variable tidal intensity around the Korean Peninsula. Furthermore, the SA indicated that predetermined acceptance error criteria were appropriate to satisfy a target central frequency (fc) for which errors fell within the specified limits (i.e., the fc equals 70%).
A standard skill assessment (SA) tool was developed and implemented to evaluate the performance of operational forecast models in the Korea operational oceanographic system. The SA tool provided a robust way to assess model skill in the system by comparing predictions and observations, and involved the computation of multiple skillmetrics including correlation and error skills. User-and system-based acceptance criteria of skill metrics were applied to determine whether predictions were acceptable for the system. To achieve this, the tool produced a time series comparison plot, a skill score table, and an advanced summarized diagram to effectively demonstrate the multiple skill scores. Moreover, the SA was conducted to evaluate both atmospheric and hydrodynamic forecast variables. For the atmospheric variables, acceptable error criteriawere preferable to acceptable correlation criteria over short timescales, since themean square error overwhelmed the observation variance. Conversely, for the hydrodynamic variables, acceptable root mean square percentage error (e.g., perms) criteria were preferable to acceptable error (e.g.,erms) criteria owing to the spatially variable tidal intensity around the Korean Peninsula. Furthermore, the SA indicated that predetermined acceptance error criteria were appropriate to satisfy a target central frequency (fc) for which errors fell within the specified limits (i.e., the fc equals 70%).
2013, 32(9): 82-90.
doi: 10.1007/s13131-013-0354-9
Abstract:
A spatial and temporal variation in physiochemical parameters in the southeastern Yellow Sea (YS) is in vestigated in the spring and summer of 2009 to 2011. Nutrient show a strong negative relationship with chlorophyll a (Chl a) concentration in spring, and the subsurface chlorophyll a maxima (SCM) layer was associated with the nitracline in summer. In summer, the SCM was usually found within or above the pycnocline and at the depths of shoals from the open sea to the coastal sea due to tidal and/or topographical fronts in the southernmost study area. High Chl a concentrations were found in the central southern YS, where the YS cold water layer expanded under the pycnocline and encountered water masses during spring and summer. After a typhoonin the summer of 2011, Chl a concentration increased, especially in the central southern YS, where cold waters occurred below the pycnocline. The results suggest that the development of thermohaline frontsmay play an important role in the growth and accumulation of phytoplankt on biomass in the upper layer of the southeastern YS during spring and summer.
A spatial and temporal variation in physiochemical parameters in the southeastern Yellow Sea (YS) is in vestigated in the spring and summer of 2009 to 2011. Nutrient show a strong negative relationship with chlorophyll a (Chl a) concentration in spring, and the subsurface chlorophyll a maxima (SCM) layer was associated with the nitracline in summer. In summer, the SCM was usually found within or above the pycnocline and at the depths of shoals from the open sea to the coastal sea due to tidal and/or topographical fronts in the southernmost study area. High Chl a concentrations were found in the central southern YS, where the YS cold water layer expanded under the pycnocline and encountered water masses during spring and summer. After a typhoonin the summer of 2011, Chl a concentration increased, especially in the central southern YS, where cold waters occurred below the pycnocline. The results suggest that the development of thermohaline frontsmay play an important role in the growth and accumulation of phytoplankt on biomass in the upper layer of the southeastern YS during spring and summer.
2013, 32(9): 91-98.
doi: 10.1007/s13131-013-0356-7
Abstract:
To investigate the distribution, abundance, and species composition of dinoflagellate cysts in the Yellow Sea, surface sediment samples were collected at 37 sites, including the Korean dump site. Twenty-one dinoflagellate cyst taxa were identified, with the assemblages dominated mainly by Spiniferites bulloideus, Operculodinium centrocarpum, and cyst of Alexandrium catenella/tamarense type. A high frequency of O. centrocarpum in the Yellow Sea was observed for the first time, and it is likely that this can be attributed to the dynamics of the Yellow Sea Cold Water Mass and the Changjiang (Yangtze) River runoff. Total cyst concentrations ranged from 23 to 48 442 cysts/g dry weight, and high cyst concentrations were recorded adjacent to the dumping site. This result suggests that anthropogenic activities such as ocean dumping stimulate the growth of dinoflagellates in the Yellow Sea, which in turn leads to high levels of dinoflagellate cyst production.
To investigate the distribution, abundance, and species composition of dinoflagellate cysts in the Yellow Sea, surface sediment samples were collected at 37 sites, including the Korean dump site. Twenty-one dinoflagellate cyst taxa were identified, with the assemblages dominated mainly by Spiniferites bulloideus, Operculodinium centrocarpum, and cyst of Alexandrium catenella/tamarense type. A high frequency of O. centrocarpum in the Yellow Sea was observed for the first time, and it is likely that this can be attributed to the dynamics of the Yellow Sea Cold Water Mass and the Changjiang (Yangtze) River runoff. Total cyst concentrations ranged from 23 to 48 442 cysts/g dry weight, and high cyst concentrations were recorded adjacent to the dumping site. This result suggests that anthropogenic activities such as ocean dumping stimulate the growth of dinoflagellates in the Yellow Sea, which in turn leads to high levels of dinoflagellate cyst production.
2013, 32(9): 99-106.
doi: 10.1007/s13131-013-0357-6
Abstract:
To understand the effects of the Yellow Sea Cold Bottom Water (YSCBW) on the diel vertical migration (DVM) of the copepod Calanus sinicus, we surveyed vertical distribution of C. sinicus at a fixed station in the Yellow Sea before (spring) and during (summer) formation of the YSCBW. Cold water (<10℃) was observed in the bottom layer when the water column was ther mally stratified in summer, but the water column was thermally well-mixed in spring 2010. Samples were collected from five different layers at 3-h intervals using an opening-closing net. Adult females (1-155 ind./m3) showed a clear normal DVM pattern throughout the entire water column in spring, whereas adultmales did notmigrate. DVM of copepodite V (CV) individuals was not clear, but the maximum abundance of CI-CIV occurred consistently in the upper 10-20 m layer, where there was a high concentration of chlorophyll-a (Chl-a) (0.49-1.19 μg/L). In summer, weak DVM was limited to coldwaters beneath the thermocline for adult females (<30 ind./m3), but not for adult males. The maximum abundance of CI-CIV also occurred consistently in the subsurface layer (20-40 m) together with high concentrations of Chl-a (0.81-2.36 μg/L). CV individuals (1-272 ind./m3) moved slightly up ward nocturnally to the near-surface layer (10-20 m), where the average temperature was 25.74℃, but they were not found in the surface layer (0-10m; 28.31℃). These results indicate that the existence of the YSBCW affected food availability at depth and the vertical temperature distribution, leading to variation in the amplitude and shape of stage-specific vertical distributions (CI to adults) in C. sinicus before and during the formation of cold waters in the Yellow Sea during the study period.
To understand the effects of the Yellow Sea Cold Bottom Water (YSCBW) on the diel vertical migration (DVM) of the copepod Calanus sinicus, we surveyed vertical distribution of C. sinicus at a fixed station in the Yellow Sea before (spring) and during (summer) formation of the YSCBW. Cold water (<10℃) was observed in the bottom layer when the water column was ther mally stratified in summer, but the water column was thermally well-mixed in spring 2010. Samples were collected from five different layers at 3-h intervals using an opening-closing net. Adult females (1-155 ind./m3) showed a clear normal DVM pattern throughout the entire water column in spring, whereas adultmales did notmigrate. DVM of copepodite V (CV) individuals was not clear, but the maximum abundance of CI-CIV occurred consistently in the upper 10-20 m layer, where there was a high concentration of chlorophyll-a (Chl-a) (0.49-1.19 μg/L). In summer, weak DVM was limited to coldwaters beneath the thermocline for adult females (<30 ind./m3), but not for adult males. The maximum abundance of CI-CIV also occurred consistently in the subsurface layer (20-40 m) together with high concentrations of Chl-a (0.81-2.36 μg/L). CV individuals (1-272 ind./m3) moved slightly up ward nocturnally to the near-surface layer (10-20 m), where the average temperature was 25.74℃, but they were not found in the surface layer (0-10m; 28.31℃). These results indicate that the existence of the YSBCW affected food availability at depth and the vertical temperature distribution, leading to variation in the amplitude and shape of stage-specific vertical distributions (CI to adults) in C. sinicus before and during the formation of cold waters in the Yellow Sea during the study period.
