共查询到10条相似文献，搜索用时 109 毫秒
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海洋表层温度对台风"蔷薇"路径和强度预测精度的影响 总被引：1，自引：0，他引：1
基于中尺度大气模式WRF(Weather Research and Forecasting Model),首先对2007年3次船舶辐射通量观测进行模拟,以检验WRF对长波和短波辐射通量的模拟能力,结果表明使用中国近海海洋环境数值预报系统环流模式POM(Princeton Ocean Model)模拟的高时空分辨率的海洋表层温度能够显著改进短波辐射通量的模拟,而对长波辐射通量模拟的改进不明显。然后,将业务化运行的中国近海海洋环境数值预报系统后报的逐时海洋表面温度(SST)作为WRF底边界条件,对2008年15号强台风"蔷薇"(Jangmi)过程进行了数值后报试验。结果表明,与使用NCEP/NCAR的SST试验后报的台风中心位置偏差相比,使用高时空分辨率的SST能够较为显著地改善"蔷薇"的路径模拟,台风中心位置模拟偏差减少11%,尤其在台风减弱阶段,台风中心位置模拟偏差减少37%。台风强度在台风发展的不同阶段对下垫面SST的变化敏感性不同。台风路径附近的海表面温度下降会导致海洋向大气输送的热量减少从而减弱台风强度。 相似文献
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基于中尺度大气模式WRF(Weather Research and Forecasting Model),首先对2007年3次船舶辐射通量观测进行模拟,以检验WRF对长波和短波辐射通量的模拟能力,结果表明使用中国近海海洋环境数值预报系统环流模式POM(Princeton Ocean Model)模拟的高时空分辨率的海洋表层温度能够显著改进短波辐射通量的模拟,而对长波辐射通量模拟的改进不明显。然后,将业务化运行的中国近海海洋环境数值预报系统后报的逐时海洋表面温度(SST)作为WRF底边界条件,对2008年15号强台风"蔷薇"(Jangmi)过程进行了数值后报试验。结果表明,与使用NCEP/NCAR的SST试验后报的台风中心位置偏差相比,使用高时空分辨率的SST能够较为显著地改善"蔷薇"的路径模拟,台风中心位置模拟偏差减少11%,尤其在台风减弱阶段,台风中心位置模拟偏差减少37%。台风强度在台风发展的不同阶段对下垫面SST的变化敏感性不同。台风路径附近的海表面温度下降会导致海洋向大气输送的热量减少从而减弱台风强度。 相似文献
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The disastrous tsunami of December 26, 2004, exposed the urgent need for implementing a tsunami warning system. One of the essential requirements of a tsunami warning system is the set up of tsunami inundation models which can predict inundation and run-up along a coastline for a given set of seismic parameters. The Tsunami Warning Centre and the State/District level Disaster Management Centres should have tsunami inundations maps for different scenarios of tsunami generation. In the event of a tsunamigenic earthquake, appropriate decisions on issue of warnings and/or evacuation of coastal population are made by referring to such maps. The nature of tsunami inundation and run-up along the Kerala coast for the 2004 Sumatra and 1945 Makran, and a hypothetical worst-case scenario are simulated using the TUNAMI N2 model and the results are presented in this paper. Further, scenarios of tsunami inundation arising out of possible rise in sea level as projected by the Intergovernmental Panel on Climate Change (IPCC 2001) are also simulated and analysed in the paper. For the study, three representative sectors of the Kerala coast including the Neendakara-Kayamkulam coast, which was the worst hit by the 2004 tsunami, are chosen. The results show that the southern locations and certain locations of central Kerala coast are more vulnerable for Sumatra when compared to Makran 1945 tsunami. From the results of numerical modelling for future scenarios it can be concluded that sea level rise can definitely make pronounced increase in inundation in some of the stretches where the backshore elevation is comparatively low. 相似文献
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M.A. Burford D.M. Alongi A.D. McKinnon L.A. Trott 《Estuarine, Coastal and Shelf Science》2008,79(3):440-448
Tropical estuaries are under increasing pressure worldwide from human impacts, but are poorly studied compared with temperate systems. This study examined a tropical macrotidal estuary, Darwin Harbour, in northern Australia, using a combination of direct measurements and literature values to determine the main sources of primary production and the sources of nutrients supporting growth. The main source of primary production was calculated to be the extensive area of fringing mangroves and resulted in a net autotrophic system (PG:R = 2.1). Much of the carbon in the mangrove forests appears to be retained within the forests or respired, as the water column was also net autotrophic despite the carbon inputs. Phytoplankton were the second largest primary producer on a whole-of-harbour basis, with low biomass constrained by light and nutrient availability. The phytoplankton were likely to be nitrogen (N) limited, based on low N:phosphorus (P) ratios, low dissolved bioavailable N concentrations (ammonium (NH4+), nitrate (NO3−), urea), and evidence that phytoplankton growth in bioassays was stimulated by NH4+ addition. The largest new source of N to the system was from the ocean due to higher N concentrations in the incoming tides than the outgoing tides. Atmospheric inputs via N fixation on the intertidal mudflats and subtidal sediments were substantially lower. The rivers feeding into the harbour and sewage were minor N inputs. Nitrogen demand by primary producers was high relative to available N inputs, suggesting that N recycling within the water column and mangrove forests must be important processes. Darwin Harbour is adjacent to the rapidly growing urban area of Darwin city, but overall there is no evidence of anthropogenic nutrient inputs having substantial effects on primary production in Darwin Harbour. 相似文献
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用于海洋环境科学的一种新方法--影响因子分析法 总被引：3，自引：0，他引：3
用影响因子法对象山港海域叶绿素a与海水理化因子之间关系分析,结果表明：水温、溶解氧(DO)、气温、盐度、化学耗氧量(COD)因子为叶绿素a浓度变化的重要有效影响因子,其中水温、溶解氧因子占主导地位。由于该海域的富营养化,N、P和Si营养盐已经不再是影响浮游植物生长的有效因子。在特定海域资料有限的情况下,影响因子法比普通的相关和灰色系统分析更具有透明性,能够有效剔除无效因子,定量表达各理化因子对叶绿素a的影响程度。用影响因子法可以明确地判断出特定海域各海水理化因子对叶绿素a影响的主次程度及其有效性,从而定量确定出影响叶绿素a浓度的主要因子。 相似文献
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Yu. P. Solov'ev 《Physical Oceanography》1990,1(3):193-201
A method applied for the determination of the statistical characteristics of the wind wave envelope is considered. It is shown that the correlation function envelope for a normal random process defines the basic properties of the process envelope and it can be expressed through the spectrum width. No limitations are imposed on the form or the width of the spectrum. The model is effective for a developing and steady sea disturbance when the attenuation of the temporal correlation function can be approximated by an exponent. Numerical computations and experimental results for typical cases of sea disturbance are compared.Translated by Mikhail M. Trufanov. 相似文献
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Seonghun Kim Kyounghoon Lee Won Duk Yoon Hyungbeen Lee Kangseok Hwang 《Ocean Science Journal》2016,51(1):59-65
Nemopilema nomurai jellyfish, which are believed to complete their development in the East China Sea, have started migrating into the Yellow Sea in recent years. We obtained biomass estimates of this species in the Yellow Sea using bottom trawl fishing gear and sighting surveys over a 5-year period. These methods are effective for obtaining N. nomurai jellyfish density estimates and information about the community distribution near the bottom or surface of the sea. To verify the vertical distributions of giant jellyfish between, we used hydroacoustic equipment, including an optical stereo camera system attached to a towed sledge and an echo counting method with scientific echosounder system. Acoustic and optical data were collected while the vessel moved at 3 knots, from which the distribution and density of N. nomurai jellyfish were analyzed. Subsequently, the camera system was towed from a 7 m mean depth to sea level, with the detection range of the acoustic system extending from an 8 m depth to the bottom surface. The optical and acoustic methods indicated the presence of vertical distribution of 0.113 (inds/m3) and 0.064 (inds/m3), respectively. However, the vertical distribution indicated that around 93% of individuals occurred at a depth range of 10–40 m; thus, a 2.4-fold greater density was estimated by acoustic echo counting compared to the optical method. 相似文献
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In general, neighboring vertical datums can be compared directly at one or more common points on the border between the datums. This direct method requires leveling and gravity measurements. Such a direct connection is not possible if the datums are separated by an ocean or another body of water. Then a rigorous mathematical model, an indirect approach, may be useful. In order to connect regional vertical datums, a rigorous mathematical model is derived based on a method by Rummel and Teunissen. In this study, two vertical datums are connected indirectly by means of a combination of precise geocentric positions of tide gauge sites and their geoid heights in one geocentric coordinate system and their height values in the respective height datums. This method is used to connect the Swedish and the Finnish height systems. The difference between Swedish RH70 and the Finnish N60 height systems is estimated to —12.1±2.7 cm. The results are mostly in good agreement with those of the direct approach by Sjöberg and by Ekman and the indirect approach by Pan and Sjöberg. 相似文献
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Comparing to single BeiDou Navigation Satellite System (BDS) Precise Point Positioning (PPP), a method which can more quicklydetermine the ambiguity parameters of BDS through applying the contribution of GPS observations is proposed and analyzed in this article. The numerical examples and analysis show that the ionosphere-free ambiguities of BDS satellites can be determined and converged more quickly because of the contribution of GPS observations. The average improvement of the convergent speed of positioning is 18.5% and its positioning accuracy in N, E, and U components are improved by 29.4, 30.3, and 34.4%, respectively, with the contribution of the a priori coordinates obtained from GPS observations. This method is useful for single BDS system positioning when there is a priori information provided by GPS or other sensors which be replaced by and can be applied at the beginning of the computation. 相似文献