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Daily rates of gross primary production, net community production and community respiration were determined in spring of 1997
at two stations in a warm streamer off Sanriku, Japan fromin vitro changes in dissolved oxygen. The phytoplankton community was composed of chlorophytes, cryptophytes and prymnesiophytes as
determined by biomarker pigment analysis. Gross production, integrated from the surface to its 1% light level was 52.5 and
80.4 mmol O2 m−2d−1. The difference in gross production is ascribed to variations in photosynthetic activity of the population. Community respiration
was 17.4 and 49.5 mmol O2 m−2d−1, and positive net community production was found within the euphotic zone. The contribution of autotrophic and heterotrophic
respiration to community respiration was estimated on the basis of the observed respiration and the phytoplankton composition.
Heterotrophic respiration was calculated to be highly variable and the observed difference in community respiration was due
to heterotrophic respiration. Heterotrophic respiration was considered to play an important role in the rapid mineralization
of organic materials. 相似文献
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为了研究西太平洋声散射层的垂向分布特征和日变化规律,分析了多波束测深系统的水体影像数据。观测结果表明,西太平洋存在着两个声散射层,一个声散射层位于0~200 m,另一个声散射层位于500~700 m,两个声散射层散射强度具有明显的日变化特征,上层散射层的散射强度呈现白天弱,夜晚强的特征,而下层散射层的散射强度日变化规律与上层相反,并且发现深散射层的厚度也存在日变化特征;分析了此种方法的优缺点,对以后声散射层的观测分析提供了新的思路。此外,利用同时下放的声速仪(SVP)的温度和深度数据对下放式声学多普勒流速剖面仪(LADCP)的观测结果进行了修正,得到了更为精确的声散射层垂向位置分布。 相似文献
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Smirnova J. E. Zabolotskikh E. V. Bobylev L. P. Chapron B. 《Izvestiya Atmospheric and Oceanic Physics》2016,52(9):1128-1136
Izvestiya, Atmospheric and Oceanic Physics - In this study polar lows over the Nordic Seas for the period of 1995–2008 have been detected and studied using the Special Sensor Microwave Imager... 相似文献
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本文分析了日本海发生的一次极地低压的水平结构和垂直结构,极地低压的"眼"处几乎无云,由螺旋状云系环绕,并伴有较强的下沉气流,具有暖核结构。热力学收支表明,该暖核主要是由伴随下沉气流的绝热增暖造成的。 相似文献
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Shipboard data from seven cruises covering April 1988–October 1990 are analyzed to follow the dynamical evolution of a persistent warm core eddy located to the southeast of Cyprus. The eddt is characterized by an isothermal, isohaline lens of water wedged between the seasonal and permanent thermoclines. In the winter, this thermostad extends from the surface to a depth of nearly 400 m, while in other seasons it lies in the layer from 200 to 400 m. The data indicate that the temperature and salinity of the core of the eddy remained constant throughout most of 1989 and then increased abruptly (with a slight increase in σφ) in the winter of 1989–1990. The velocity jet usually appears between the surface and 200 m at a mean distance of 35 km from the center of the eddy. Speeds in the jets typically exceed 25 cm s−1 and occasionally reach 50 cm s−1. During 1989 the eddy spins down as indicated by a loss of kinetic energy. This weakening permits an abrupt renewal or exchange of core water during the winter of 1989–1990. The remnants of the previous core are apparently forced to sink into the permanent thermocline where the water may be free to spread laterally if the cross-isopycnal gradient of potential vorticity is weak. This process could explain the cycle of Levantine Intermediate Water formation in the centers of warm core eddies and its eventual lateral spreading. Finally the eddy slowly begins to spin up again in 1990. 相似文献
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AstudyofanewretrievalalgorithmformeasurementofoceanicwindvectorsfieldusingsatellitemicrowavescatterometerLinMingsen,SunYing,Z... 相似文献
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Josh N. Plant Kenneth S. Johnson Steve E. Fitzwater Carole M. Sakamoto Luke J. Coletti Hans W. Jannasch 《Deep Sea Research Part I: Oceanographic Research Papers》2010,57(12):1585-1595
An In Situ Ultraviolet Spectrophotometer (ISUS) was coupled to a benthic chamber to characterize the bisulfide flux emanating from a warm spring at the Extrovert Cliff locality within Monterey Bay, California. The chamber was periodically flushed with bottom seawater to reset chemical concentrations, which enabled deployments over multiple days. Data from several deployments, each lasting at least 10 days, were used to calculate flow rates, fluid concentrations, and fluxes over time. The bisulfide concentration of the fluid entering the chamber varied from 75 to 4500 μmol l?1. Positive temperature anomalies up to 3.5° were associated with these elevated concentrations. Linear flow rates ranged from 2 to >17 m day?1, while the bisulfide fluxes varied from 0.2 to 80 mol m?2 day?1. The bisulfide originated at depth and was not produced in the surface sediments via an anaerobic oxidation of methane coupled to sulfate reduction. Tides modulated the flow as well as the composition of the fluid entering the chamber. It appeared that a deep sourced fluid, which supplied the bisulfide, was mixed with a second, ambient seawater-like fluid before entering the flux chamber. At low tides, flow rates were at their highest and the contribution of the deep sourced fluid to the fluid entering the chamber was at a maximum. 相似文献
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一种利用SMOS卫星观测的海表面盐度反演海水盐度廓线的方法 总被引:4,自引:1,他引:3
This paper proposes a new method to retrieve salinity profiles from the sea surface salinity(SSS) observed by the Soil Moisture and Ocean Salinity(SMOS) satellite. The main vertical patterns of the salinity profiles are firstly extracted from the salinity profiles measured by Argo using the empirical orthogonal function. To determine the time coefficients for each vertical pattern, two statistical models are developed. In the linear model, a transfer function is proposed to relate the SSS observed by SMOS(SMOS_SSS) with that measured by Argo, and then a linear relationship between the SMOS_SSS and the time coefficient is established. In the nonlinear model, the neural network is utilized to estimate the time coefficients from SMOS_SSS, months and positions of the salinity profiles. The two models are validated by comparing the salinity profiles retrieved from SMOS with those measured by Argo and the climatological salinities. The root-mean-square error(RMSE) of the linear and nonlinear model are 0.08–0.16 and 0.08–0.14 for the upper 400 m, which are 0.01–0.07 and 0.01–0.09 smaller than the RMSE of climatology. The error sources of the method are also discussed. 相似文献
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Heat content change in the surface isothermal layer of a typical warm core ring in the sea east of Japan is described based
on approximately 90 CTD profiles obtained by one profiling float. Erosion of the seasonal thermocline and development of a
surface isothermal layer from the mid-summer to the early winter of 1999 are clearly seen. While heat content change between
two consecutive profiles with a 35-hour time interval is much noisier, its 10-day running mean is consistent with net surface
heat flux, indicating that surface heat flux dominates the temporal heat content change in the surface isothermal layer in
the warm core ring. 相似文献
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Distinctions between the longitudinal structures of circulation in the stratosphere and mesosphere/lower thermosphere of the Northern and Southern hemispheres are investigated on the basis of the temperature and geopotential distributions obtained with a SABER instrument (TIMED satellite) in the months of February and August in 2002–2005. The positions of the winter cyclone and polar vortex at stratospheric and mesospheric heights in 2002–2005 are compared to the climatic data over 1978–1998. At stratospheric heights, the mean position of the polar vortex’s center over several years changed insignificantly during the specified years (several degrees in latitude and longitude) in both the Southern and Northern hemispheres. At mesosphere/lower thermosphere heights, the polar vortex occupies the same position in the Southern Hemisphere each year during 2002–2005, and this position agrees with the estimates for 1996–1997. Parameters of stationary planetary waves with the zonal wave number 1 (SPW1) in the fields of temperature, geopotential, and wind are calculated from data on the temperature and geopotential. The height profiles of SPW1 amplitudes and phases calculated from the SABER instrument data for August in the Southern Hemisphere are in good agreement with the profiles of amplitudes and phases obtained from the direct wind measurements with HRDI and WINDII instruments. A strong interannual variability of SPW1 parameters is observed in the Northern Hemisphere. The calculation of the Eliassen-Palm flux and its divergence has shown that SPW1 penetrates into the mesosphere mainly from the stratosphere and slows down the zonal mean flux. However, in the Southern Hemisphere, there is a regular additional SPW1 source with the center at a height of about 65 km and a latitude of 55°S. Such a SPW1 source is, on average, absent in the Northern Hemisphere during 2002–2005; however, in some years (for example, in February 2004), its existence is possible. 相似文献
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Michael Reynolds 《Ocean Engineering》1983,10(1):65-76
A small, inexpensive, and easily deployable meteorological buoy is described. Buoy motion is greatly reduced by appropriate ballast techniques; vector averaging further removes buoy motion effects from wind data. Data is transmitted to the GOES satellite and is retrieved by telephone. Measurements are vector-averaged wind components, wind speed, wind direction, water temperature, air temperature, and compass direction. Data from two field trials are discussed. Speed comparisons averaged 0.2 m sec−1 with a standard deviation of 0.6 m sec−1. Direction comparisons were different due to local topography, but they indicate a probable accuracy of ±5°. 相似文献
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Ken Furuya Osamu Hasegawa Takashi Yoshikawa Satoru Taguchi 《Journal of Oceanography》1998,54(5):545-552
The light-saturated maximum value (P
B
max) and initial slope (α) of the photosynthesis-irradiance (P-E) curve were examined in a warm streamer, a cold streamer and
a warm core ring off the Sanriku area in the subarctic western North Pacific Ocean during an ADEOS/OCTS Sanriku field campaign
in early May 1997. BothP
B
max and α were within the ranges of temperate populations. A regional difference was apparent inP
B
max: populations in the warm streamer tended to show higher value ranging between 1.92 and 4.74 mgC (mgChla)−1h−1 than those in the cold streamer and the warm core ring (1.35–2.87 mgC (mgChla)−1h−1). A depth variation was also observed in α in both the warm streamer and the warm core ring: shallow populations tended to
have lower α than deep populations. The depth variations in bothP
B
max and α resulted in a lower light intensity of the light saturation in a deeper population than that of a shallower one. These
depth-related variations in the P-E parameters were likely a manifestation of “shade-adaptation” of photosynthesis. Photoinhibition
was not observed over in situ surface light intensity varying below ca 1600 μmol photon m−2s−1. Water-column primary productivity was biooptically estimated to be 233 to 949 mgC m−2d−1 using vertical distributions of the P-E parameters, chlorophylla, phytoplankton light absorption and underwater irradiance. Applicability of surface data sets for estimation of water-column
productivity is discussed. 相似文献
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Atmospheric frontal gravity waves observed in satellite SAR images of the Bohai Sea and Huanghai Sea 总被引:1,自引:0,他引:1
LIU Shuming LI Ziwei YANG Xiaofeng Pichel William G YU Yang ZHENG Quanan LI Xiaofeng 《海洋学报(英文版)》2010,29(5):35-43
In the satellite synthetic aperture radar (SAR) images of the Bohai Sea and Huanghai Sea, the authors observe sea surface imprints of wave-like patterns with an average wavelength of 3.8 km. Comparing SAR observations with sea surface wind fields and surface weather maps, the authors find that the occurrence of the wave-like phenomena is associated with the passing of atmospheric front. The authors define the waves as atmospheric frontal gravity waves. The dynamical parameters of the wave packets are derived from statistics of 9 satellite SAR images obtained from 2002 to 2008. A two-dimensional linear physical wave model is used to analyze the generation mechanism of the waves. The atmospheric frontal wave induced wind variation across the frontal wave packet is compared with wind retrievals from the SAR images. The CMOD-5 (C-band scatterometer ocean geophysical model function) is used for SAR wind retrievals VV (transmitted vertical and received vertical) for ENVISAT and HH (transmitted horizontally and received horizontally) for RADARSAT-1. A reasonable agreement between the analytical solution and the SAR observation is reached. This new SAR frontal wave observation adds to the school of SAR observations of sea surface imprints of AGWs including island lee waves, coastal lee waves, and upstream Atmospheric Gravity Waves (AGW). 相似文献