2023 Vol. 45, No. 5
Display Method:
2023, 45(5): 1-13.
doi: 10.12284/hyxb2023074
Abstract:
Here we examine the history of sea ice activity recorded in the Core LV87-54-1 recovered from the northern Okhotsk Sea shelf using high-resolution grain-size analyses. We extracted 3 end members and use EM3 as the sea-ice proxy, using the program AnalySize to conduct end members analyses on the data. According to EM3 results, active sea ice was persistently predominant in the northern Okhotsk Sea shelf since the Last Glacial Maximum. The EM3 content was high and the sea ice activity was intense during the Last Glacial Maximum and Heinrich Stadial 1. The climate cooling at the middle and high latitudes of the Northern Hemisphere and the negative Arctic Oscillation were the main controlling mechanism for sea ice expansion during glacial periods. And weakened runoff from the Amur caused by decreased East Asian Summer Monsoon would allow more sea ice formation in the Okhotsk Sea. Sea ice formation decreased at the onset of the Bølling-Allerød warm period, and then decreased sharply after a slight peak during the Younger Dryas Event. EM3 levels remained low stably since the Holocene due to: increased local autumn insolation, positive Arctic Oscillation and enhanced East Asian Summer Monsoon suppresses subsequent sea ice formation.
Here we examine the history of sea ice activity recorded in the Core LV87-54-1 recovered from the northern Okhotsk Sea shelf using high-resolution grain-size analyses. We extracted 3 end members and use EM3 as the sea-ice proxy, using the program AnalySize to conduct end members analyses on the data. According to EM3 results, active sea ice was persistently predominant in the northern Okhotsk Sea shelf since the Last Glacial Maximum. The EM3 content was high and the sea ice activity was intense during the Last Glacial Maximum and Heinrich Stadial 1. The climate cooling at the middle and high latitudes of the Northern Hemisphere and the negative Arctic Oscillation were the main controlling mechanism for sea ice expansion during glacial periods. And weakened runoff from the Amur caused by decreased East Asian Summer Monsoon would allow more sea ice formation in the Okhotsk Sea. Sea ice formation decreased at the onset of the Bølling-Allerød warm period, and then decreased sharply after a slight peak during the Younger Dryas Event. EM3 levels remained low stably since the Holocene due to: increased local autumn insolation, positive Arctic Oscillation and enhanced East Asian Summer Monsoon suppresses subsequent sea ice formation.
2023, 45(5): 14-26.
doi: 10.12284/hyxb2023076
Abstract:
Carrying out researches on marine sediments’ source can help to better understand the mechanism of material transport and the process of regional and global material circulation. A sediment provenance study has been conducted by analyzing the rare earth element and Sr-Nd isotopes of the ANT36-C4-05 core sediment in the Cosmonaut Sea, Antarctic. The results show that the average content of rare earth element (REE) in the sediment is relatively high, with an obvious fractionation between light REE (LREE) and heavy REE (HREE); and the average 87Sr/86Sr value of the sediment is relatively high, while the average εNd(0) value is significantly negative. The REE and Sr-Nd isotopic characteristics indicate that since the late Middle-Holocene, the sediment is mainly originated from high-grade metamorphic rocks in the vicinity of the Prydz Bay and Enderby Land, East Antarctic. These detrital materials are partly introduced into the Cosmonaut Sea under the ice-sea interaction, with the Antarctic Coastal Current and Antarctic Slope Current playing important roles in the transportation; simultaneously, it may also rely on katabatic winds originating from the Antarctic interior plateau to complete the transport process from source areas to the study area. The results of the provenance end member mixing model show that the sediment is mainly originated from metamorphic rocks in the Prydz Bay area (>70%), while the contribution from Enderby Land is relatively small. The significant difference in the contribution of two source areas is related to the differences in glaciers, ocean currents, and wind forces between two areas: compared to Enderby Land, the glacier in the Prydz Bay area is larger in scale and moves at a faster speed, with a stronger erosive and transport capacity for the bedrock; in the meanwhile, the Antarctic Bottom Water originating from the bottom of the Prydz Bay area may play an important role during the westward transportation; and the Prydz Bay area is one of the stronger wind force regions of katabatic winds, which can contribute more bedrock debris to downwind areas, for example the Cosmonaut Sea. These factors result in the characteristic of the ANT36-C4-05 core sediment in the Cosmonaut Sea which is mainly from the Prydz Bay area.
Carrying out researches on marine sediments’ source can help to better understand the mechanism of material transport and the process of regional and global material circulation. A sediment provenance study has been conducted by analyzing the rare earth element and Sr-Nd isotopes of the ANT36-C4-05 core sediment in the Cosmonaut Sea, Antarctic. The results show that the average content of rare earth element (REE) in the sediment is relatively high, with an obvious fractionation between light REE (LREE) and heavy REE (HREE); and the average 87Sr/86Sr value of the sediment is relatively high, while the average εNd(0) value is significantly negative. The REE and Sr-Nd isotopic characteristics indicate that since the late Middle-Holocene, the sediment is mainly originated from high-grade metamorphic rocks in the vicinity of the Prydz Bay and Enderby Land, East Antarctic. These detrital materials are partly introduced into the Cosmonaut Sea under the ice-sea interaction, with the Antarctic Coastal Current and Antarctic Slope Current playing important roles in the transportation; simultaneously, it may also rely on katabatic winds originating from the Antarctic interior plateau to complete the transport process from source areas to the study area. The results of the provenance end member mixing model show that the sediment is mainly originated from metamorphic rocks in the Prydz Bay area (>70%), while the contribution from Enderby Land is relatively small. The significant difference in the contribution of two source areas is related to the differences in glaciers, ocean currents, and wind forces between two areas: compared to Enderby Land, the glacier in the Prydz Bay area is larger in scale and moves at a faster speed, with a stronger erosive and transport capacity for the bedrock; in the meanwhile, the Antarctic Bottom Water originating from the bottom of the Prydz Bay area may play an important role during the westward transportation; and the Prydz Bay area is one of the stronger wind force regions of katabatic winds, which can contribute more bedrock debris to downwind areas, for example the Cosmonaut Sea. These factors result in the characteristic of the ANT36-C4-05 core sediment in the Cosmonaut Sea which is mainly from the Prydz Bay area.
2023, 45(5): 27-38.
doi: 10.12284/hyxb2023062
Abstract:
Combined with hydrometeorological data, a six-day tracking survey was carried out in the coastal waters of Changhua Town, Changjiang County, western Hainan Island on March 10 to 15, 2022. And this study analyzed the variation characteristics of environmental factors and influencing factors in the process of Phaeocystis globose bloom. During the peak of the bloom, the abundance of Phaeocystis globosa and CODMn were as high as 3.10×108 cells/L and 35 mg/L, which were much higher than those reported in other areas. The rainfall and wind wave disturbance before the bloom promoted the terrestrial runoff and the release of sedimentary nutrients, which provided material conditions for the bloom. The sudden rise of temperature induces the bloom, and the larger tidal range and lower wind speed create favorable external conditions for the accumulation along the colony. During the elimination of the bloom, the concentrations of DIN, PO4-P, DO, CODMn and Mn decreased significantly, in which DIN and PO4-P were the limiting factors, and DO, CODMn and Mn were important characteristic factors. After the yellow colony broken, the concentrations of Chl a and SiO3-Si also decreased rapidly, and then slowly increased or even higher than the peak concentration level, when the diatom abundance represented by Chaetoceros curvisetus gradually increased. The study also preliminarily explores the basic generation and elimination process of the bloom, which provides an important reference for the further study of the bloom mechanism of P. globosa in this area.
Combined with hydrometeorological data, a six-day tracking survey was carried out in the coastal waters of Changhua Town, Changjiang County, western Hainan Island on March 10 to 15, 2022. And this study analyzed the variation characteristics of environmental factors and influencing factors in the process of Phaeocystis globose bloom. During the peak of the bloom, the abundance of Phaeocystis globosa and CODMn were as high as 3.10×108 cells/L and 35 mg/L, which were much higher than those reported in other areas. The rainfall and wind wave disturbance before the bloom promoted the terrestrial runoff and the release of sedimentary nutrients, which provided material conditions for the bloom. The sudden rise of temperature induces the bloom, and the larger tidal range and lower wind speed create favorable external conditions for the accumulation along the colony. During the elimination of the bloom, the concentrations of DIN, PO4-P, DO, CODMn and Mn decreased significantly, in which DIN and PO4-P were the limiting factors, and DO, CODMn and Mn were important characteristic factors. After the yellow colony broken, the concentrations of Chl a and SiO3-Si also decreased rapidly, and then slowly increased or even higher than the peak concentration level, when the diatom abundance represented by Chaetoceros curvisetus gradually increased. The study also preliminarily explores the basic generation and elimination process of the bloom, which provides an important reference for the further study of the bloom mechanism of P. globosa in this area.
2023, 45(5): 39-52.
doi: 10.12284/hyxb2023064
Abstract:
Beibu Gulf is located in the northwestern part of the South China Sea and is experiencing a significant increase in the frequency, duration and extent of harmful algal blooms (HABs) outbreaks in the last 30 years. To characterize phytoplankton and bacterial communities during the massive Noctiluca scintillans bloom in the Beibu Gulf, seawater samples were collected from the area of a massive N. scintillans outbreak west from Weizhou Island on February 21, 2021, and environmental factors, along with phytoplankton and bacterial communities were analyzed. The results showed that the sea water quality of this area met the standards of Chinese Class I seawater quality, mainly in the absolute phosphate limit state. In recent years, other studies reported low nutrient content and limited phosphorus in waters adjacent to Weizhou Island and in the central part of Beibu Gulf during the non-harmful algal bloom (HAB) period. Therefore, N. scintillans bloom investigated in this study belonged to a non-eutrophication HAB event. Two phyla, five genera, and five species of phytoplankton were identified in seawater, among which N. scintillans was the absolute dominant species, with a cell density of 2.00×103–3.75×103 cells/L. The red discoloration of the sea water was caused by the red heterotrophic N. scintillans. Both phylogenetic and genetic distance analyses demonstrated that the causative N. scintillans in the Beibu Gulf was similar to N. scintillans along the coast of China. High-throughput sequencing of the V3–V4 region of the 16S rRNA gene in seawater samples revealed that the number of OTUs (operational taxonomic units) in bacterial community ranged from 294 to 414, with Alphaproteobacteria and Gammaproteobacteria as the dominant groups. The bacterial community structure was affected by various environmental factors, including COD, DO, DIN,\begin{document}${\rm{PO}}_4^{3-} $\end{document} ![]()
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Beibu Gulf is located in the northwestern part of the South China Sea and is experiencing a significant increase in the frequency, duration and extent of harmful algal blooms (HABs) outbreaks in the last 30 years. To characterize phytoplankton and bacterial communities during the massive Noctiluca scintillans bloom in the Beibu Gulf, seawater samples were collected from the area of a massive N. scintillans outbreak west from Weizhou Island on February 21, 2021, and environmental factors, along with phytoplankton and bacterial communities were analyzed. The results showed that the sea water quality of this area met the standards of Chinese Class I seawater quality, mainly in the absolute phosphate limit state. In recent years, other studies reported low nutrient content and limited phosphorus in waters adjacent to Weizhou Island and in the central part of Beibu Gulf during the non-harmful algal bloom (HAB) period. Therefore, N. scintillans bloom investigated in this study belonged to a non-eutrophication HAB event. Two phyla, five genera, and five species of phytoplankton were identified in seawater, among which N. scintillans was the absolute dominant species, with a cell density of 2.00×103–3.75×103 cells/L. The red discoloration of the sea water was caused by the red heterotrophic N. scintillans. Both phylogenetic and genetic distance analyses demonstrated that the causative N. scintillans in the Beibu Gulf was similar to N. scintillans along the coast of China. High-throughput sequencing of the V3–V4 region of the 16S rRNA gene in seawater samples revealed that the number of OTUs (operational taxonomic units) in bacterial community ranged from 294 to 414, with Alphaproteobacteria and Gammaproteobacteria as the dominant groups. The bacterial community structure was affected by various environmental factors, including COD, DO, DIN,
2023, 45(5): 53-63.
doi: 10.12284/hyxb2023060
Abstract:
Flow velocity is one of the key environmental factors for deep sea aquaculture. In order to further understand the molecular regulation mechanism of golden pompano (T. ovatus) under flow velocity stress, the fishes were stressed under the static water, medium flow velocity (54 cm/s) and high flow velocity (90 cm/s), and the LC/MS metabolomics technology was used to explore the changes of endogenous metabolites in the liver to look for differential metabolites and related metabolic pathways. The results show that 51 metabolites in the medium flow velocity group have significant difference with which in the static water and are enriched in 40 pathways, mainly including galactose metabolism, gluconeogenesis, biosynthesis of unsaturated fatty acids, arachidonic acid metabolism, etc. Forty metabolites in the high flow velocity group have significant difference with which in the static water and are enriched in 22 pathways, mainly including biosynthesis of unsaturated fatty acids, pantothenate and CoA biosynthesis, lysine degradation, arachidonic acid metabolism, linoleic acid metabolism, etc. Compared with the medium flow velocity group, 31 metabolites in the high flow velocity group have significant difference and are enriched in 12 pathways, mainly including arachidonic acid metabolism, adipocytokine signaling pathway, cysteine and methionine metabolism, etc. Pathway analysis shows that both medium and high flow velocity stress promoted unsaturated fatty acid metabolism, arachidonic acid metabolism and pantothenic acid synthesis. The ability of swimming is improved to against the stress of flow velocity by strengthening metabolism. The medium flow velocity group mainly significantly affected the metabolism of galactose, cysteine and methionine. At this time, more and more energy produced by fish is used for exercise. The high flow velocity group mainly significantly affect the metabolism of L-lysine and retinoic acid, which reveals that the swimming ability of fish may be decreased and some immune functions may be triggered under the high flow velocity stress.
Flow velocity is one of the key environmental factors for deep sea aquaculture. In order to further understand the molecular regulation mechanism of golden pompano (T. ovatus) under flow velocity stress, the fishes were stressed under the static water, medium flow velocity (54 cm/s) and high flow velocity (90 cm/s), and the LC/MS metabolomics technology was used to explore the changes of endogenous metabolites in the liver to look for differential metabolites and related metabolic pathways. The results show that 51 metabolites in the medium flow velocity group have significant difference with which in the static water and are enriched in 40 pathways, mainly including galactose metabolism, gluconeogenesis, biosynthesis of unsaturated fatty acids, arachidonic acid metabolism, etc. Forty metabolites in the high flow velocity group have significant difference with which in the static water and are enriched in 22 pathways, mainly including biosynthesis of unsaturated fatty acids, pantothenate and CoA biosynthesis, lysine degradation, arachidonic acid metabolism, linoleic acid metabolism, etc. Compared with the medium flow velocity group, 31 metabolites in the high flow velocity group have significant difference and are enriched in 12 pathways, mainly including arachidonic acid metabolism, adipocytokine signaling pathway, cysteine and methionine metabolism, etc. Pathway analysis shows that both medium and high flow velocity stress promoted unsaturated fatty acid metabolism, arachidonic acid metabolism and pantothenic acid synthesis. The ability of swimming is improved to against the stress of flow velocity by strengthening metabolism. The medium flow velocity group mainly significantly affected the metabolism of galactose, cysteine and methionine. At this time, more and more energy produced by fish is used for exercise. The high flow velocity group mainly significantly affect the metabolism of L-lysine and retinoic acid, which reveals that the swimming ability of fish may be decreased and some immune functions may be triggered under the high flow velocity stress.
2023, 45(5): 64-78.
doi: 10.12284/hyxb2023050
Abstract:
To identify abalone species effectively for better management and protection of abalone germplasm resources, we have obtained the complete mitochondrial genome of juvenile green abalone (Haliotis fulgens) through high-throughput sequencing, and its sequences and structural characteristics are analyzed accordingly. The results show that the mitogenome of H. fulgens is 17 041 bp in total length and encoded 37 genes, including 13 protein coding genes, 22 transfer RNA (tRNA) genes and 2 ribosomal RNA (rRNA) genes. The 13 protein coding genes used AUG as the starting codon and UAA or UAG as the termination codon. Twenty-one tRNA genes other than tRNA-Ser(AGN) could be folded into a typical cloverleaf structure. There is a rich A+T non-coding region between tRNA-Glu and COX3, with two hairpin structures containing palindromes in it. A phylogenetic tree was constructed based on the reported complete mitochondrial genome sequences of Haliotis genus species, and phylogenetic analysis shows that H. fulgens is clustered with H. discus hannai, H. rufescens and H. cracherodii. Comparing the domains of 13 proteins of mitogenome of H. fulgens and H. discus hannai, we found the number of transmembrane domains of ND2 or ND4 dehydrogenase subunits were different in them. Whether this is related to the difference of high temperature tolerance between them needs further study. In brief, the first acquisition and analysis of the complete mitochondrial genome of H. fulgens has enriched the abalone cellular genetic information, and provided basic data and references for abalone species classification, germplasm identification, and protection of germplasm resources of H. fulgens as well.
To identify abalone species effectively for better management and protection of abalone germplasm resources, we have obtained the complete mitochondrial genome of juvenile green abalone (Haliotis fulgens) through high-throughput sequencing, and its sequences and structural characteristics are analyzed accordingly. The results show that the mitogenome of H. fulgens is 17 041 bp in total length and encoded 37 genes, including 13 protein coding genes, 22 transfer RNA (tRNA) genes and 2 ribosomal RNA (rRNA) genes. The 13 protein coding genes used AUG as the starting codon and UAA or UAG as the termination codon. Twenty-one tRNA genes other than tRNA-Ser(AGN) could be folded into a typical cloverleaf structure. There is a rich A+T non-coding region between tRNA-Glu and COX3, with two hairpin structures containing palindromes in it. A phylogenetic tree was constructed based on the reported complete mitochondrial genome sequences of Haliotis genus species, and phylogenetic analysis shows that H. fulgens is clustered with H. discus hannai, H. rufescens and H. cracherodii. Comparing the domains of 13 proteins of mitogenome of H. fulgens and H. discus hannai, we found the number of transmembrane domains of ND2 or ND4 dehydrogenase subunits were different in them. Whether this is related to the difference of high temperature tolerance between them needs further study. In brief, the first acquisition and analysis of the complete mitochondrial genome of H. fulgens has enriched the abalone cellular genetic information, and provided basic data and references for abalone species classification, germplasm identification, and protection of germplasm resources of H. fulgens as well.
2023, 45(5): 79-89.
doi: 10.12284/hyxb070
Abstract:
Implementation of the artificial sandbar is a typical measure for the beach nourishment. Research on the morphological evolution of the artificial sandbar meets the important need for coastal protection and restoration. Domestic and international research on morphological evolution of nearshore artificial sandbar and underlying sediment transport mechanisms are summarized in this paper, focusing on the theoretical aspects, e.g. cross-shore migration, morphology evolution, morphology coupling and mechanisms of sediment transport of the artificial sandbar. In the methodology perspective, the description of the equilibrium profile and numerical modelling of morphology evolution of the artificial sandbar are also highlighted. It is also proposed that future research should focus on the deepening of mechanisms of key processes, the improvement of simulation and prediction methods and the application of practical beach nourishment projects.
Implementation of the artificial sandbar is a typical measure for the beach nourishment. Research on the morphological evolution of the artificial sandbar meets the important need for coastal protection and restoration. Domestic and international research on morphological evolution of nearshore artificial sandbar and underlying sediment transport mechanisms are summarized in this paper, focusing on the theoretical aspects, e.g. cross-shore migration, morphology evolution, morphology coupling and mechanisms of sediment transport of the artificial sandbar. In the methodology perspective, the description of the equilibrium profile and numerical modelling of morphology evolution of the artificial sandbar are also highlighted. It is also proposed that future research should focus on the deepening of mechanisms of key processes, the improvement of simulation and prediction methods and the application of practical beach nourishment projects.
2023, 45(5): 90-106.
doi: 10.12284/hyxb2023058
Abstract:
Quantitative analysis on the properties of marine phytoplankton bloom events is helpful to understand the marine ecology, environment, and dynamic processes. In the South China Sea, remote sensing is vulnerable to clouds. Previous studies were mostly conducted with discontinuous observation or remote sensing data, which failed to comprehensively understand the characteristics and controlling factors of marine bloom events in the South China Sea. This study applied the statistical framework for defining marine heat waves, based on previously reconstructed daily full coverage remotely sensed chlorophyll a product from 2005 to 2019, to extract marine bloom events in two representative subregions, i.e., the northwestern Luzon in winter and southeastern Vietnam in summer. The duration, intensity, and corresponding long-term trends of marine bloom events in the two representative sea areas were analyzed. The results showed that the bloom frequency in the Luzon Strait has decreased, while the intensity has increased. These trends were significant in most areas for the winter Luzon Strait, while the trends for most of the summer Vietnam coasts were not significant. We further analyzed the influencing factors of marine bloom events and found that the winds (positive correlation) and sea surface temperature (negative correlation) had the greatest impacts on the bloom events. In both two representative sea areas, the marine bloom events were mainly dominated by upwelling, and the wind was the most important influencing factor. Analysis on the precursor conditions of marine bloom events found that the sub-mesoscale activity represented by the temperature front is also an important influencing factor. The study applied in South China Sea as a case study, as well can provide a new perspective to study marine ecosystem and environment.
Quantitative analysis on the properties of marine phytoplankton bloom events is helpful to understand the marine ecology, environment, and dynamic processes. In the South China Sea, remote sensing is vulnerable to clouds. Previous studies were mostly conducted with discontinuous observation or remote sensing data, which failed to comprehensively understand the characteristics and controlling factors of marine bloom events in the South China Sea. This study applied the statistical framework for defining marine heat waves, based on previously reconstructed daily full coverage remotely sensed chlorophyll a product from 2005 to 2019, to extract marine bloom events in two representative subregions, i.e., the northwestern Luzon in winter and southeastern Vietnam in summer. The duration, intensity, and corresponding long-term trends of marine bloom events in the two representative sea areas were analyzed. The results showed that the bloom frequency in the Luzon Strait has decreased, while the intensity has increased. These trends were significant in most areas for the winter Luzon Strait, while the trends for most of the summer Vietnam coasts were not significant. We further analyzed the influencing factors of marine bloom events and found that the winds (positive correlation) and sea surface temperature (negative correlation) had the greatest impacts on the bloom events. In both two representative sea areas, the marine bloom events were mainly dominated by upwelling, and the wind was the most important influencing factor. Analysis on the precursor conditions of marine bloom events found that the sub-mesoscale activity represented by the temperature front is also an important influencing factor. The study applied in South China Sea as a case study, as well can provide a new perspective to study marine ecosystem and environment.
2023, 45(5): 107-117.
doi: 10.12284/hyxb2023068
Abstract:
As an important material, energy and information exchange channel between land and sea, the development of the tidal creek would determine the vegetation growth and succession on the tidal flats. The growth of vegetation would also influence the evolution of the tidal creek and the topography. The aim of this study was to investigate the distribution of tidal flats vegetation types in the Yancheng coastal wetland, Jiangsu Province and their influence on tidal creek development. Through the UAV technology, the inversion of the tidal flats topographic elevation model and the extraction of vegetation information, it observed the tidal flats of southern Tiaozini. The results showed that: (1) with the expansion of the cordgrass (Spartina alterniflora) community, the original salt marsh vegetation on the tidal flats appeared to shrink in patches; (2) as the tidal channel extended inland, the bottom of the channel was gradually occupied by cordgrass which showed an obvious distribution along the tidal creeks; (3) there were littoral ridges on both sides of the tidal creek, and cordgrass has the effect to uplift the terrain of the topography of tidal creeks and the tidal flat nearby. The development of tidal creeks would accelerate the invasion of cordgrass, and its invasion can change the original topography and vegetation compositions of the tidal flats. This contributed to the understanding of how tidal creeks affected the distribution of vegetation populations as they developed on the tidal flats. It demonstrated the inverse effect of vegetation distribution on the tidal creek development. The study could provide some reference for the local management of cordgrass and the use of drone technology in it.
As an important material, energy and information exchange channel between land and sea, the development of the tidal creek would determine the vegetation growth and succession on the tidal flats. The growth of vegetation would also influence the evolution of the tidal creek and the topography. The aim of this study was to investigate the distribution of tidal flats vegetation types in the Yancheng coastal wetland, Jiangsu Province and their influence on tidal creek development. Through the UAV technology, the inversion of the tidal flats topographic elevation model and the extraction of vegetation information, it observed the tidal flats of southern Tiaozini. The results showed that: (1) with the expansion of the cordgrass (Spartina alterniflora) community, the original salt marsh vegetation on the tidal flats appeared to shrink in patches; (2) as the tidal channel extended inland, the bottom of the channel was gradually occupied by cordgrass which showed an obvious distribution along the tidal creeks; (3) there were littoral ridges on both sides of the tidal creek, and cordgrass has the effect to uplift the terrain of the topography of tidal creeks and the tidal flat nearby. The development of tidal creeks would accelerate the invasion of cordgrass, and its invasion can change the original topography and vegetation compositions of the tidal flats. This contributed to the understanding of how tidal creeks affected the distribution of vegetation populations as they developed on the tidal flats. It demonstrated the inverse effect of vegetation distribution on the tidal creek development. The study could provide some reference for the local management of cordgrass and the use of drone technology in it.
2023, 45(5): 118-128.
doi: 10.12284/hyxb2023066
Abstract:
In the field of ocean remote sensing research, the construction of a high temporal resolution sea surface wind (SSW) dataset through the use of multi-source satellite data has become a popular topic. This article aims to quantitatively evaluate the error characteristics and calibration coefficients of SSW speed data obtained from different sensors using buoy data and ERA5 for the satellites scatterometer and radiometer in orbit simultaneously in 2019. The unit error of various satellite remote sensing SSW is comparatively analyzed, providing technical support for quantitative applications such as multi-source satellite SSW blending and assimilation. Furthermore, compared with equal neutral wind speeds, the wind speeds inferred by microwave scatterometer and radiometer are better suited to be interpreted by stress-equivalent winds, which enables the optimal application of satellite remote sensing data. The SSW speeds remotely sensed by existing scatterometers and radiometers are generally consistent with the buoy and ERA5 stress-equivalent wind, but exhibit some deviations at high wind speeds (wind speed greater than 20 m/s). An indicator factor for lateral comparison of wind speed errors is proposed to achieve relative error estimation of scatterometer and radiometer wind speeds, which provides an important reference for error setting in multi-source data assimilation applications. The results demonstrate that the inherent wind speed errors of the five scatterometers range from 0.40 to 0.73, and the inherent wind speed errors of the five microwave radiometers range from 0.86 to 1.23. In conclusion, it can be observed that the scatterometers generally exhibit better accuracy in SSW speed estimation than radiometers in the wind speed range of 0 m/s to 20 m/s.
In the field of ocean remote sensing research, the construction of a high temporal resolution sea surface wind (SSW) dataset through the use of multi-source satellite data has become a popular topic. This article aims to quantitatively evaluate the error characteristics and calibration coefficients of SSW speed data obtained from different sensors using buoy data and ERA5 for the satellites scatterometer and radiometer in orbit simultaneously in 2019. The unit error of various satellite remote sensing SSW is comparatively analyzed, providing technical support for quantitative applications such as multi-source satellite SSW blending and assimilation. Furthermore, compared with equal neutral wind speeds, the wind speeds inferred by microwave scatterometer and radiometer are better suited to be interpreted by stress-equivalent winds, which enables the optimal application of satellite remote sensing data. The SSW speeds remotely sensed by existing scatterometers and radiometers are generally consistent with the buoy and ERA5 stress-equivalent wind, but exhibit some deviations at high wind speeds (wind speed greater than 20 m/s). An indicator factor for lateral comparison of wind speed errors is proposed to achieve relative error estimation of scatterometer and radiometer wind speeds, which provides an important reference for error setting in multi-source data assimilation applications. The results demonstrate that the inherent wind speed errors of the five scatterometers range from 0.40 to 0.73, and the inherent wind speed errors of the five microwave radiometers range from 0.86 to 1.23. In conclusion, it can be observed that the scatterometers generally exhibit better accuracy in SSW speed estimation than radiometers in the wind speed range of 0 m/s to 20 m/s.
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