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本文在多年试验研究的基础上，研制了一套较为完善的黄海中部近海海域海洋气象预报服务的专门系统，本系统可进行海上大风、海水表层温度、以及风浪预报，并具备海上天气的实时监测和动态决策服务的能力。 相似文献
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Late Pleistocene sequences around Dundalk Bay, eastern Ireland, record glaciomarine sedimentation near the margin of a grounded ice lobe around 15 ka BP. A coastal exposure at Cooley Point consists of four major facies deposited outside this ice limit. (1) A basal mud facies deposited from sediment plumes accumulated following the initial ice marginal retreat inland. It contains a well-preserved Arctic microfauna dominated by the foram Elphidium clavatum and the ostracod Roundstonia globulifera. (2) A flat to undulating boulder facies (pavement), mostly one clast thick, is found pressed into the mud and is characterized by bevelled and striated upper clast surfaces. Pavement attributes are a result of intertidal activity in a cold climate. The boulder source is due to rafting by ice floes from glacigenic debris deposited during an ice advance. (3) Laminated sand facies drape the pavement and are a result of variable current activity. (4) The overlying gravel facies is separated from the sand facies by a marine erosion surface. The gravel facies is subaqueous, channelized and is overlain by late glacial raised beach ridges. Locally the gravels have been deformed by ice pressure from partially floating ice floes. Facies changes record terrestrial submergence and provide evidence for changes in relative sea level during part of the last deglacial cycle. The boulder pavement and deformed gravel facies suggest that ice floes and sea ice effects may be more common within stratigraphies along emergent coasts than previously thought, though they have a low preservation potential. Extreme conditions during the deglacial favoured opportunistic microfaunas during mud deposition. This event may be related to a major meltwater event within the Irish Sea Basin. 相似文献
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《African Journal of Marine Science》2013,35(1):97-106
Long time-series of sea surface temperature (SST) and pseudo wind stress (τ) in six areas in the South-East Atlantic are analysed as possible inputs into fisheries models. The areas encompass oceanic and coastal regimes. A clear seasonal signal is evident in all areas, with an amplitude in SST of 3–4°C in the upwelling areas and 5°C farther offshore and on the Agulhas Bank. Warming lags in the north and offshore by 1–2 months. Monthly variability is highest in the upwelling areas. An increasing trend in SST is suggested in all areas, the post-World War II era being about 1,0°C warmer than earlier periods. Some coherence occurs between areas at times, although at other times the anomalies are distinctly out of phase. There is a suggestion of an upward trend in the equatorward wind stress in some offshore areas after 1964, with a sharp change in 1975. Benguela Niños are evident in the environmental record and have a periodicity of around 10 years. 相似文献
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《African Journal of Marine Science》2013,35(2):501-504
The extent to which the relationship between juvenile abalone Haliotis midae and sea urchins Parechinus angulosus is induced by their physical habitat along the Namaqualand coast of South Africa was investigated. Correlation analyses between the proportion of abalone utilising sea urchins for refuge and the proportion of habitat defined as exposed were computed from 28 experimental seeding sites in Port Nolloth on the north-west coast of South Africa. A highly significant positive correlation was found (r = 0.72, p < 0.05). It was concluded that, along the Namaqualand coast, under-boulder habitat was the most important factor determining the survival of juvenile abalone (size 12–26mm). Site selection should therefore be based on the suitability of the physical substratum to provide shelter for juvenile abalone along that coast. 相似文献
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《African Journal of Marine Science》2013,35(3-4):493-509
High-resolution (1km) satellite data from the NOAA AVHRR (Advanced Very High Resolution Radiometer) and OrbView-2 SeaWiFS (Sea-viewing Wide Field-of-view Sensor) are used to investigate the upper layer dynamics of the southern Benguela ecosystem in more detailed space and time scales than previously undertaken. A consistent time-series of daily sea surface temperature (SST) and chlorophyll a concentration images is generated for the period July 1998–June 2003, and a quantitative analysis undertaken. The variability in SST, upwelling and phytoplankton biomass is explored for selected biogeographic regions, with particular focus on intra-seasonal time scales. The location and emergence of upwelling cells are clearly identified along the length of the southern Benguela, being distinct on the narrow inner and the mid-continental shelves. Most notable is the rapidly pulsating nature of the upwelling, with intense warm/cold events clearly distinguished. The phytoplankton response to this physical forcing is described. Chlorophyll concentration on the inner shelf largely mirrors the pattern of SST variability, similarly dominated by event-scale processes. Over the mid-shelf, higher chlorophyll is observed throughout all seasons, although low biomass occurs during winter. The variability of the offshore extent of SST and chlorophyll is identified at locations of differing shelf width. Cooler upwelled water is confined primarily to the narrow inner-shelf, with event-scale pulses extending considerable distances offshore. Agulhas Current influences are readily observed, even on the Cape Peninsula inner-shelf. Chlorophyll concentrations vary considerably between the locations of differing shelf width. SST, upwelling and phytoplankton indices are derived for selected locations to quantify the intra-seasonal variations. The SST indices show marked temperature changes associated with rapid pulsation on the event scale. No strong seasonal signal is evident. In contrast, the upwelling indices display a strong seasonal signal, with most intense upwelling occurring in spring/summer in the south. The phytoplankton response to the seasonal upwelling index differs between the selected locations. This study concludes that, although low-resolution SST and chlorophyll data may be useful for investigating general patterns over large scales, higher resolution data are necessary to identify finer scale spatial and temporal variability, especially in the inshore coastal zones. 相似文献
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《African Journal of Marine Science》2013,35(1):331-361
Assessment of the status of southern bluefin tuna (SBT) by Australia and Japan has used a method (ADAPT) that imposes a number of structural restrictions, and is similar to methods used for a number of stocks world-wide. A flexible method for assessment of the SBT population is presented that is much less restrictive and has potentially wide applicability. The three key features are: (1) all fitting to data is within the context of maximum likelihood, (2) catch-at-age data are not assumed to be without error (as in existing methods), but rather to be random variables, while age-specific selectivity is allowed to change over time within the bounds of specific structure, and (3) autocorrelation in recruitment processes is considered within the likelihood framework of the model. While the results suggest the stock has been depleted considerably from its virgin biomass, and are generally consistent with previous assessments, they also indicate that it is not as much below the biomass that will produce maximum suitable yield as previously estimated and that the extent of stock rebuilding necessary may not be as large as has been argued. The available data are shown to provide little information on the steepness parameter of the stock-recruitment function, and hence on sustainable catch levels for the stock. 相似文献
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《African Journal of Marine Science》2013,35(3):473-490
Hypotheses regarding temperature, food abundance and food size were tested to explore niche separation between Calanoides carinatus, an abundant copepod in the cool and food-rich southern Benguela upwelling system, and Calanus agulhensis, the dominant copepod on the warmer, relatively food-poor Agulhas Bank off the south coast of South Africa. Under non-limiting food conditions, egg production by both species increased linearly with temperatures between 9°C and 18°C. Egg production by C. carinatus was relatively faster at 21°C, but was offset by greater mortality. Both species showed similar functional responses to food concentration in the field, reaching satiation at ～15mg Chl a m?3, or ～3–4ppm. Food abundance was the most important predictor of egg production, whether measured as Chl a or as particle volume. Both species preferred larger particles that dominated the biomass peak, but particle size appeared more important for C. carinatus, with increasingly faster rates of egg production as the proportion of large cells (>10μm) exceeded 50%, and slower ingestion of small (<10μm) cells. Omnivory may be more important to C. agulhensis. Niche separation between the two species appears unrelated to temperature, food abundance or diel vertical migratory behaviour, and is more likely a function of variability in food availability, although food size may also play a role. 相似文献