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Time series changes in sea surface temperature (SST), chlorophyll a (Chl a), nutrients (PO4, NO3), and sea winds, which correlated with the passage of Typhoon Shanshan in the East/Japan Sea (EJS), are illustrated using satellite data for Chl a, SST, sea winds, and in situ data for nutrients and water temperature. The sea-surface cooling (SSC) effect by the passage of the typhoon was higher at stations nearer to the center compared to stations further from the center. The SSC effect at stations in the colder water region (on the left side of the typhoon’s track) was higher than at stations in the Tsushima Warm Current region (on the right side of the typhoon). The SSC effect continued for approximately 10 days after the passage of the typhoon. The Chl a concentration at all stations increased after the passage of the typhoon. This increase continued for a period of approximately 10 days, but the duration period at each station varied with distance from the typhoon center. Changes in Chl concentrations at stations within a 2° distance on both sides from the typhoon’s center were higher than that at other stations. The changes in Chl a by the passage of the typhoon were measured at approximately 0.3–1.0 mg/m3 along the moving path of the typhoon. Phosphate and nitrate changes were inversely correlated with the water temperature changes; the nutrient concentration increased with the passage of the typhoon. Like the changes in SST, changes in nutrient concentrations on the left side of the typhoon’s track were higher compared to those at the center and the right side. 相似文献
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A. N. Gruzdev E. P. Kropotkina S. V. Solomonov A. S. Elokhov 《Izvestiya Atmospheric and Oceanic Physics》2017,53(2):195-203
Using results of ground-based spectrometric measurements, we analyze the anomalies in the stratospheric contents of O3 and NO2 in the Moscow region related to the sudden stratospheric warming and associated distortion of the stratospheric circumpolar vortex in early February 2010 and to the latitudinal displacement of the vortex towards the European sector in late March 2011 before the final spring warming. In the former case, the O3 concentration increased up to 85% and the stratospheric column NO2 content increased twice; in the latter case, the O3 concentration decreased by a quarter and the NO2 content decreased twice in comparison with average values for the time periods preceding the onsets of the anomalies. Estimates of the statistical correlationship of the stratospheric O3 and NO2 contents with potential vorticity and geopotential have been obtained. 相似文献
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Dag Myrhaug 《Journal of Oceanography》2016,72(4):661-662
A paper by Iida et al. that was recently published in this journal (J Oceanogr 17:637–661, 2015) presented trends in the partial pressure of carbon dioxide in surface seawater and the estimated sea–air carbon dioxide flux over the global open oceans for the last two decades. The purpose of the present discussion is to demonstrate that the formula used by Iida et al. in their assessments can also be employed to estimate the sea–air carbon dioxide flux based on long-term wind statistics, i.e., based on data showing how the mean wind speed 10 m above the sea surface has varied over a long period. Examples of the application of this approach are given here, based on long-term wind statistics for the northern North Sea and the North West Shelf of Australia. 相似文献
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Isotope parameters (δD, δ<Superscript>18</Superscript>O) and sources of freshwater input to Kara Sea
The isotope characteristics (δD, δ18О) of Kara Sea water were studied for quantitative estimation of freshwater runoff at stations located along transect from Yamal Peninsula to Blagopoluchiya Bay (Novaya Zemlya). Freshwater samples were studied for glaciers (Rose, Serp i Molot) and for Yenisei and Ob estuaries. As a whole, δD and δ18O are higher in glaciers than in river waters. isotope composition of estuarial water from Ob River is δD =–131.4 and δ18O =–17.6‰. Estuarial waters of Yenisei River are characterized by compositions close to those of Ob River (–134.4 and–17.7‰), as well as by isotopically “heavier” compositions (–120.7 and–15.8‰). Waters from studied section of Kara Sea can be product of mixing of freshwater (δD =–119.4, δ18O =–15.5) and seawater (S = 34.9, δD = +1.56, δ18O = +0.25) with a composition close to that of Barents Sea water. isotope parameters of water vary significantly with salinity in surface layer, and Kara Sea waters are desalinated along entire studied transect due to river runoff. concentration of freshwater is 5–10% in main part of water column, and <5% at a depth of >100 m. maximum contribution of freshwater (>65%) was recorded in surface layer of central part of sea. 相似文献
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The age and growth of filefish, Thamnaconus modestus (Günther 1877) in the southern waters of Korea were investigated. Samples were collected with commercial trawl catches during the period from May 2009 to December 2011. Of the 2,626 specimens collected, the sex ratio was not significantly different from 1:1 (P > 0.05). The total length ranged from 11.3 to 42.1 cm. The gonadosomatic index for both sexes was the highest in May to June, indicating that May to June is the main spawning period. The length of females at sexual maturity was 25.92 cm. The length-weight relationship of the filefish was TW = 0.0121TL3.0536 (n = 1,692, r2 = 0.9034, P < 0.001). The age of the sampled individuals was estimated by counting growth rings recorded on the 5th vertebrae; ages ranged from 0 to 9 years. The filefish of the same age displayed a high individual variation in total length. Length-at-age data were fitted by using the Von Bertalanffy growth model. The estimated Von Bertalanffy growth parameters were L∞ = 42.04 cm, k = 0.21 year?1 and t0 = ?1.56 for females, L∞ = 41.20 cm, k = 0.18 year?1 and t0 = ?2.36 for males, and L∞ = 43.16 cm, k = 0.17 year?1 and t0 = ?2.18 for the combination of both male and female. These data can be used as useful biological information for the future fishery management of filefish resources in Korean waters. 相似文献
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Artificial hatching and fry culture of Bostrichthys sinensis (Lacépède) has been successful under conditions of enclosed seawater circulation system in the Aquarium Lab, South China Sea Fish. Res. Inst, on the 13th of April, 1984. The development of each stage of the eggs, larvae and juveniles are described, and colour photographs of every development stage were taken. According to their physiological characteristics in each stage, necessary ecological conditions for the developments are preliminarily discussed. 相似文献
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Roger Searle 《Marine Geology》1977,25(4):299-320
A detailed survey of a 1°-square of sea floor 100 miles northeast of the Azores has revealed the presence of scarps over 30 km long striking generally 120°, transverse to the regional topographic and magnetic lineations. They are not associated with a major fracture zone. Sedimentation in the area appears to have been by a mixture of pelagic and turbidity-current processes, with a Miocene increase in sedimentation rate probably indicating the subaerial emergence of the Azores Archipelago. Magnetic anomalies were identified along a number of profiles between the survey area and the Mid-Atlantic Ridge crest, and indicate a short period of increased spreading rate from about 12-3 m.y. ago. 相似文献
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Sayaka Yasunaka Yukihiro Nojiri Taketo Hashioka Chisato Yoshikawa Taketoshi Kodama Shin-ichiro Nakaoka Sanae Chiba Fuminori Hashihama Masahide Wakita Ken Furuya Daisuke Sasano Akihiko Murata Hiroshi Uchida Michio Aoyama 《Journal of Oceanography》2018,74(1):1-11
We used more than 25,000 nutrient samples to elucidate for the first time basin-scale distributions and seasonal changes of surface ammonium (NH4 +) and nitrite (NO2 ?) concentrations in the Pacific Ocean. The highest NH4 +, NO2 ?, and nitrate (NO3 ?) concentrations were observed north of 40°N, in the coastal upwelling region off the coast of Mexico, and in the Tasman Sea. NH4 + concentrations were elevated during May–October in the western subarctic North Pacific, May–December in the eastern subarctic North Pacific, and June–September in the subtropical South Pacific. NO2 ? concentrations were highest in winter in both hemispheres. The seasonal cycle of NH4 + was synchronous with NO2 ?, NO3 ?, and satellite chlorophyll a concentrations in the western subtropical South Pacific, whereas it was synchronous with chlorophyll-a but out of phase with NO2 ? and NO3 ? in the subarctic regions. 相似文献
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Baoxiao Qu Jinming Song Huamao Yuan Xuegang Li Ning Li Liqin Duan 《Journal of Oceanography》2017,73(3):365-382
In this work, we examined the carbonate parameters, i.e. total alkalinity (TA), pH, and partial pressure of CO2 (pCO2), and the air–sea CO2 flux (FCO2) in the continental shelves of the southern Yellow Sea (SYS) and East China Sea (ECS), based on two field surveys conducted in April and August of 2011. Surface pCO2 showed significant spatial variations, ranging from 246 to 686 µatm in spring (average ± standard deviation = 379 ± 95 µatm) and from 178 to 680 µatm in summer (384 ± 114 µatm). During the spring cruise, the central SYS (pCO2 < 240 µatm) and the Changjiang estuary (pCO2 < 300 µatm) were under-saturated with CO2, while the southern SYS and the southwestern ECS were supersaturated (pCO2 = 420–680 µatm). In summer, however, the CO2-supersaturated waters (pCO2 = 380–680 µatm) occupied a relatively wide area, including the nearshore of the SYS and the Changjiang estuary, whereas pCO2-deficient water (pCO2 = 220–380 µatm) was observed only at the offshore ECS. In general, the entire SYS and ECS area behaved as a sustained CO2 sink, with average FCO2 of ?3.9 and ?2.1 mmol m?2 d?1 in spring and summer, respectively. Phytoplankton production was the driving force for CO2 absorption, especially during the spring cruise. In addition, we found that typical water mixing processes and decomposition of terrestrial material were responsible for the release of CO2 in three turbidity maximum regions. 相似文献
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Assume that the Tonglu Canal would be widened and deepened in which a water lock is constructed at the river side, and made open to the sea side.The canal''s planned control dimensions are determined, and the erosion and siltation characteristics along the river (totally 81.8 km) are analyzed by the numerical calculation of one-dimensional unsteady flow and the relative standards.According to the data of the evolution, hydrology and sediment in the Xiaomiaohong Waterway, it is found reasonable to select the channel near the Xingang Gate as the second sea-entering approach.This paper is helpful in planning and designing the approach. 相似文献
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Bacteria abundance, chlorophyll a, ATP and POC concentrations and respiration rates of microorganisms in the Changjiang Estuary and the plume were determined in July 1986. The high values of bacteria abundance occurred in the river mouth in association with suspended matter. It is assumed that bacteria were the major contributor to ATP and the main consumer of dissolved oxygen, and that the relationship between ATP and POC was present in that area. In the dilution zone (salinity; 25-30), instead of bacteria, phytoplankton was the major contributor to ATP and respiration rates, due to diatom bloom. Close relationships between Chi a and ATP, and ATP and POC were observed. Contribution of microbial carbon to POC was also estimated. 相似文献
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Abstract Phosphorus and nitrogen were measured in stream run‐off from the four catchments of the Taita Experimental Basin (41° 11′ S, 174° 58′ E). The land is used as exotic conifer forest, native forest, and hill pasture. Multiple regression analysis was used to estimate chemical losses per unit area in floods and at low flows. At low flows, the hill pasture (fertilised with lime at 630 kg·ba?1·y?1, and superphosphate at 380 kg·ha?1·y?1) tended to lose more phosphorus and nitrate than the forested land, but differences were small, and not always significant. During large floods, the hill pasture (No. 5 Catchment) lost about 3 times as much reactive phosphate and 2–5 times as much total phosphorus as the forested land, and 130–190 times as much nitrate as land in the Exotic Forest and Native Forest 2 Catchments. Nitrate losses from land in the No. 4 Catchment (mainly native forest) were as high as those from the hill pasture, so high nitrate loss is not associated solely with agriculture. Losses of total phosphorus via the catchment streams were estimated as: No. 5 Catchment (hill pasture), 293 g·ha?1·y?1; Native Forest 2 Catchment, 201 g·ha?1·y?1; No. 4 Catchment, 124 g·ha?1·y?1; Exotic Forest Catchment, 71 g·ha?1.y?1. Nitrate‐N losses were estimated to have been 1356 g·ha?1·y?1, 11.5 g·ha?1·y?1, 1436 g·ha?1·y?1, and 44 g·ha?1·y?1 respectively. Phosphorus and nitrate concentrations were similar in the Exotic Forest and Native Forest 2 streams, but the Exotic Forest tended to lose smaller amounts because it yielded about 50% less water per unit area. Over the 2‐y study, an estimated 47–70% of phosphorus losses and up to 83% nitrate losses occurred in large floods; 31% and 48% respectively were apparently lost from the hill pasture catchment in a single flood. Less than 20% of estimated phosphorus losses and as little as 1% of nitrate losses occurred at low flows. Run‐off of phosphorus and nitrate was spasmodic, and this should be considered in assessing the impact of surface run‐off on the biology and chemistry of receiving waters. 相似文献
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Ariyoshi Keisuke Kuwano-Yoshida Akira Chi Wu-Cheng 《Marine Geophysical Researches》2019,40(4):451-451
Marine Geophysical Research - 相似文献
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《Deep Sea Research Part II: Topical Studies in Oceanography》1999,46(3-4):815-842
Zooplankton communities, studied in the surface mixed layer on a 1600 m transect across the Arabian Sea, were found to differ in their temporal and spatial response to seasonal forcing. The transect studied, spanned seasonally eutrophic upwelling, mesotrophic downwelling and aseasonal oligotrophic waters. The nano- and microzooplankton communities constituted a relatively constant compartment in the tropical monsoon ecosystem, whilst the mesozooplankton showed a clear response to both upwelling and season. The heterotrophic nanoflagellates were concentrated in the surface mixed layer, except in the eutrophic upwelling waters of the SW monsoon. They reached maximum cell concentrations of 855 ml-1 during the SW monsoon and a maximum biomass of 8.4 mg C m-3 during the intermonsoon. Nanozooplankton standing stocks, in the surface mixed layer, ranged between 7 and 333 mg C m-2, with highest stocks found during the intermonsoon. The microzooplankton community was dominated by Protozoa, particularly aloricate ciliates and heterotrophic dinoflagellates, which accounted for up to 99% in terms of numbers and up to 71% of the biomass. Sarcodines and metazoan nauplii were recorded in lower numbers (<400 l-1). The microzooplankton were also concentrated in the surface mixed layer during both periods, except in the eutrophic coastal waters during the SW monsoon, when relatively high biomass values were found below the mixed layer depth. Their standing stocks, in the surface mixed layer, ranged between 50 and 182 mg C m-2, with the highest concentration found in the mesotrophic offshore waters during the late monsoon period. Total mesozooplankton standing stocks, in the surface 100 m, decreased with distance from the coastal to offshore waters and between seasons, decreasing from 1248 to 238 mg C m-2 during the late SW monsoon and 656–89 mg C m-2 during the following intermonsoon. The largest size class, of 1000–2000 μm sized organisms, dominated throughout except at the oligotrophic station during the intermonsoon period, when the smallest class, of 200–500 μm, were more important. The shift in size structure from large to small zooplankton occurred in response to a shift in dominance from large to small phytoplankton cells both spatially, along a eutrophic–oligotrophic gradient, and seasonally. These responses are a result of the physical forcing associated with the monsoon seasons in the Arabian Sea. 相似文献