F2层临界频率的太阴半日周期扰动分析

大气太阴潮汐对ES层和F2层有影响,在ES层和F2层的参数中均发现以太阴半日周期的振荡.通过分析中低纬地区10个台站F2层临界频率(foF2)的太阴半日分量变化,得到以下结论:foF2太阴半日潮有日变化和季节变化.不同的纬度,太阴半日潮的日变化、季节变化不同.武汉foF2太阴半日潮出现最强的月份、武汉中层低热层大气太阴半日潮汐风最强的月份、武汉ES层参数的太阴半日潮最大值出现的月份均相同,这表明,中层和低热层大气太阴半日潮汐和ES层、F2层的太阴半日潮汐有非常强的相关性.     

A numerical study on nonlinear propagation and short-term variability of the migrating diurnal and semidiurnal tides

By using a three-dimensional fully nonlinear numerical model in spherical coordinates and taking the linear steady solutions of the migrating diurnal and semidiurnal tides in January from the Global-Scale Wave Model （GSWM） as the initial values, we simulate the linear and nonlinear propagations of the migrating diurnal and semidiurnal tides in the atmosphere from the ground to the lower thermosphere. A comparison of our simulations with the results of GSWM is also presented. The simulation results show that affected by the nonlinearity, the migrating diurnal and semidiurnal tides propagating in the middle and upper atmosphere exhibit evident short-term variability. The nonlinear interactions between the migrating tides and the background atmosphere can obviously alter the background wind and temperature fields, which suggests that the nonlinear propagations of the migrating diurnal and semidiurnal tides impact significantly on the transient dynamical and thermal structures of the background middle and upper atmosphere and the nonlinear effect is an important cause of the difference between the results of GSWM and observations.     

基于高频地波雷达观测的粤港澳大湾区春季海表流特征研究

基于高频地波雷达系统监测得到的海表流资料, 选取907个高密度空间点, 运用调和分析等方法, 探究粤港澳大湾区2020年3月的潮流特征。结果表明, 该海域潮流以不规则半日潮M2分潮为主, 且浅水分潮影响显著。主要全日分潮和半日分潮的倾角都在120°~160°之间, 即最大流速都为西北?东南流向, 表现为向岸?离岸流动的趋势。随着与海岸线距离的增加, 潮型系数和浅水系数逐渐增大, 区域南部离岸区表现出不规则全日潮的特征。可能最大流速和实测最大流速的范围分别为0.33~71.01 cm/s和58.63~149.99 cm/s, 其大值都分布于研究区的西北部和南部。     

Potential relationships between atmospheric particulate matter transported by winter monsoons and red tides in the East China Sea

Combining numerical diagnosis from atmospheric science with biogeochemical methods,a model of the potential correlation of monsoons with red tide emergence in the East China Sea is constructed.The model is designed based on an in-depth investigation of the time-space relationship of aerosol and red tide events in the East China Sea from 2005 to 2006,and a continuous monitoring of atmospheric particulates at two stations.The study shows that every red tide event investigated has a close relationship with aerosols coming from the northwest (wind direction in winter) along with subsidence flow.The elemental abundance of total suspended particulate in Hangzhou and Tiantai is different from that of soil background levels,indicating atmospheric particulates there are brought in by winter winds.There is a significant correlation between the content of iron and phosphorous in atmospheric particulates,which mainly exist in binding materials between particulates.In addition,the confined absorption of iron and phosphorous by red tides is related to the intensity of sunlight.These results provide new information regarding the mechanism for the high frequency of red tides in the East China Sea.The results also provide a scientific basis for establishing new pathways for pre-warning and forecasting of red tide disasters.     

First observation of mesospheric and thermospheric winds by a Fabry-Perot interferometer in China

A Fabry-Perot interferometer, funded by the Meridian Project in China, was deployed at the Xinglong station (40.2°N,117.4°E) of the National Astronomical Observatories in Hebei Province, China. The instrument has been operating since April 2010, measuring mesospheric and thermospheric winds. The first observational data of winds at three heights in the mesosphere and thermosphere were analyzed, demonstrating the capacity of this instrument to aid basic scientific research. The wavelengths of three airglow emissions were OH892.0, OI 557.7, and OI 630.0 nm, which corresponded to heights of 87, 98, and 250 km, respectively. Three 38-day data sets of horizontal winds, from April 5, 2010 to May 12, 2010, show clear day-to-day variations at the same height. The minimum and maximum meridional winds at heights of 87, 98, and 250 km were –16.5 to 8.7 m/s, –24.4 to 15.9 m/s, and –43.6 to 1.5 m/s. Measurements of zonal winds were –5.4 to 7.6 m/s, 2.3 to 23.0 m/s, and –22.6 to 49.3 m/s. The average data from the observations was consistent with the data from HWM93. The wind data at heights of 87 and 98 km suggest a semi-diurnal oscillation, clearly consistent with HWM93 results. Conversely there was a clear discrepancy between the observations and the model at 250 km. In general, this Fabry-Perot interferometer is a useful ground-based instrument for measuring mesospheric and thermospheric winds at middle latitudes.     

烟台外海潮波的特征

在烟台外海,潮汐属于正规半日潮性质,而潮流属于日潮流性质.用数值模拟和实测潮流分析两种方法研究了该特征并解释造成这一现象的原因:在烟台外海M2分潮具有驻波振动,存在着M2分潮流的辐聚、辐散现象,因而该海域M2分潮流很小.该海域日分潮流没有辐聚、辐散现象,因而日分潮流相对较强,从而造成了该海域的潮汐、潮流性质相异的特殊现象.     

台州湾附近海域潮汐、潮流特性

利用临时验潮站横门站的1a潮位观测资料、下大陈站长期验潮资料以及4个垂线测站的大、中、小潮潮流同步观测资料,分析了台州湾附近海域的潮汐、潮流特征,并探讨了海平面空间分布特征的影响因素.结果表明:横门站与下大陈站的潮汐类型均属于正规半日潮类型;横门站年平均潮差大于下大陈站4 cm;2站平均涨、落潮历时相当;台州湾除T-1...     

基于钦州湾验潮站2008-2020年潮位序列的潮汐特征研究

潮汐是钦州湾的主要海洋动力,对物质输运、海洋工程、海洋生态环境等都有重要影响。本研究基于钦州湾验潮站2008-2020年共13年的水位观测资料,利用潮汐调和分析、偏度计算和线性回归等方法,分析钦州湾长时间的潮汐变化、潮不对称性特征及海平面变化趋势。结果表明,钦州湾验潮站潮汐以O₁、K₁分潮占优,属于规则全日潮。主要分潮振幅有显著的年际变化,2008年为最小值,O₁为95.82 cm, K₁为88.18 cm, M₂为39.53 cm; 2016年达到最大值,O₁为104.27 cm, K₁为95.15 cm, M₂为46.16 cm,这一变化与月赤纬角的变化有关。钦州湾潮不对称现象显著,涨潮历时比落潮历时多2-3 h,造成该现象的主要原因是受到半日分潮和全日分潮之间相互作用的影响,其中主要贡献来源于O₁、K₁、M₂之间的相互作用,占总潮汐偏度的80...     

HF Radar Observation of Tidal Current over the Beibu Gulf,South China Sea

In this paper, a new fully-digital high frequency(HF) radar system OSMAR-SD(ocean state measuring and analyzing radar, S-smaller, D-digital) is employed for observation of the tidal current over the Beibu Gulf, South China Sea. This system can operate at two frequencies to achieve wider range and better resolution of measurement. Experimental results show that the radar measurements agree with the tide level data well. The environmental noise level is also analyzed to demonstrate its detrimental effect upon the measurement, the period of this effect is about 24 h. Moreover, it's the first time that the characteristic of the irregular diurnal tide over Beibu Gulf is clearly measured by HF radar.     

Global structures of the DE3 tide

The Hough mode decomposition (HMD) is used to investigate the global structures of the eastward propagating diurnal tide of zonal wavenumber 3 (DE3). The tide is delineated by using the SABER/ TIMED temperatures collected during 2002―2006. The HMD analysis results show that the DE3 tide is primarily dominated by two leading propagating Hough modes, i.e., (-3, 3) and (-3, 4) modes; the in-fluences .of the other Hough modes including trapped modes can be neglected. Based upon the HMD analysis results, this paper first reported the maximum of the tidal activity in the MLT region. The re-sults show that the DE3 tide exhibits annual unimodal distribution with the maximal amplitude occur-ring at 110 km in late summer (around July each year). Moreover, characteristic 2-year period variation is observed in the (-3, 3) Hough mode. And this type of inter-annual variation is further reflected in the tidal amplitude at 110 km height. For example, corresponding to the 2-year variation of the (-3, 3) mode, the DE3 tidal amplitude exhibits two substantially enhanced activities with maximal amplitude exceed-ing 12 K in 2002 and 2004, respectively. Moreover, current investigation results indicate that the influ-ence of the second propagating Hough mode, (-3, 4) mode, is important, in particular at the height un-der 100 km, where the DE3 amplitudes exhibit antisymmetric distribution with respect to the equator. The (-3, 4) mode exhibits bimodal distribution over a yearly course, which dominates the DE3 tide in the lower mesosphere. For example, two maximal DE3 activities were observed in late-winter-to-early- spring and late-autumn-to-early-winter, respectively. The first maximum is seen in the south of the equator, and the second maximum is in the north of it.     

Correlation between ionospheric longitudinal harmonic components and upper atmospheric tides

There is strong correlation among the ionospheric longitudinal structures of wavenumber-3 (WN3), wavenumber-4 (WN4), and eastward-propagating diurnal tides with zonal wave numbers s = 2 and 3 (DE2 and DE3) in the upper atmosphere. The total electron content derived from the Global Ionospheric Maps of the Jet Propulsion Laboratory is used to deduce the latitudinally total electron content (ITEC) in the low-latitude ionosphere, and TIDE/TIMED observations are employed to obtain zonal and meridian winds of the mesopause and lower thermosphere. Through Fourier transformation, various ionospheric longitudinal harmonic components and tidal patterns are derived from the ionospheric and upper-atmospheric observations, and we compare the annual/inter-annual variations in ionospheric harmonic components WN3 and WN4 with those in atmospheric tides (DE2 and DE3). It is found that the annual and inter-annual variations in WN3 and WN4 are consistent with those in DE2 and DE3 zonal wind components respectively, while they are inconsistent with those in the meridian components. We then decompose the harmonic components into “tidal patterns”, finding that the “DE2” and “DE3” patterns are the main parts of WN3 and WN4 respectively. Their annual and inter-annual variations are similar to those of atmospheric tidal patterns (DE2 and DE3). Complex correlation results show that correlation between the ionospheric “DE2” in WN3 and the atmospheric tidal DE2 zonal wind component is quite strong in the Northern Hemisphere, while that between the ionospheric “DE3” in WN4 and the atmospheric tidal DE3 zonal wind component is much stronger at low latitudes. At the same time, the contribution of the meridian wind component is very weak. Above all, the atmospheric tidal DE2 and DE3 patterns are important factors of the ionospheric WN3 and WN4 structures.     

2001—2017年中国近海水域赤潮发生规律及其影响因素

通过收集整理2001—2017年相关数据, 对我国近海海域赤潮爆发规律及影响因素进行初步探究。结果表明, 我国近海海域赤潮发生规律呈先增后减趋势, 2001—2005年, 近海赤潮面积和频次大幅度增加, 2006—2017年则明显减少。2008—2017年, 我国发生赤潮608 次, 引发赤潮的第一优势物种有65种。其中, 东海原甲藻(Prorocentrum donghaiense)是引发赤潮次数最多的生物, 共计106次。各海区赤潮的影响因素有差异: 渤海区赤潮面积变化主要受营养盐和总氮影响, 东海区赤潮面积和次数变化与营养盐、总氮、总磷和亚硝态氮显著相关, 南海区赤潮面积变化与污染物入海量和CODcr显著正相关(P<0.05)。为进一步减少赤潮爆发, 提出我国近海海域赤潮防治建议: 建设在线监测站点, 采取因区制宜的管控措施, 加强源头排污管理, 完善应急响应体系, 进行海洋生态修复。     

Internal tide characteristics over northern South China Sea continental slope

21-day in-situ ADCP current and CTD data from an anchored observational station by R/V Shiyan 3 are used to investigate the characteristics of intemal tide in the northern South China Sea continental slope. The results show that tide and internal tide are both mixed type in the observed region and dominated by diurnals; the maximum internal tidal major axes of K1, O1 were largest and reached 11 cm/s, 10 cm/s, respectively, and their current vectors rotate anticlockwise. The 300 m-deep internal tide presents obvious quasi-diurnal oscillation and its average amplitude reaches 50 m. Furthermore, internal tide carried high energy; in the upper layers above 140 m, the kinetic energy of intemal tides accounts for 15%--37% of overall kinetic energy, most of internal tide energy concentrates around the thermocline.     

中国大陆境内的O1分波应变负荷潮

根据Schwideiski海潮图,本文根据作者提出的积分Green函数方法计算了全球海潮O_1分波在中国大陆产生的应变负荷潮,并绘制了应变负荷潮在中国大陆的分布图。分布图表明,中国大陆全境的O_1分波应变负荷潮受太平洋海潮的控制,在中国南部沿海地区南海海潮的作用非常显著,此处应变负荷潮的振幅可以接近甚至超过固体潮的振幅,即使在大陆西部内陆地区,负荷潮的振幅亦可达固体潮振幅的百分之几。要合理解释应变固体潮的观测结果,正确考虑负荷潮的影响是十分必要的。     

FVCOM模型在渤海湾潮流潮汐模拟中的应用

浅海是潮运动占优的海域,潮汐、潮流对物质输运和水交换有重要影响．采用非结构有限体积近岸海洋模型（FVCOM）模拟渤海湾的三维潮汐潮流分布和变化规律,非结构网格能真实地拟合岸线,刻画出渤海湾的复杂岸线,能够较好地计算出渤海湾的潮汐潮流的时空分布特点,与实测值吻合较好．模拟的M,分潮振幅的平均方差为7．33cm,迟角的平均方差为11．53°．在渤海湾,M2分潮的最大振幅为120cm,湾内的迟角差为70°;渤海湾湾中潮余流较弱,流速在0—0．6cm／s．渤海湾是潮流较强的区域,海区的最大可能潮流流速超过100cm／s．     

基于中频雷达探测资料的中层大气潮汐

利用Lomb—Scargle周期图法和谐波拟合法分析武汉中频雷达试验站2002年2月6日到3月6日的探测数据，水平风场的LS功率谱显示武汉上空存在很强的24h潮汐波动，在某些高度上还会出现较强的12h和弱的8h潮汐。24h潮汐是中层顶区域主要的潮汐成分，谐波拟舍的方法表明，24h潮汐的振幅在88km达到最大，并且其能量是向上传播的。     

淤泥质海岸泥沙运动模拟及进港航道大风天回淤特性研究

建立波浪、潮流共同作用下的泥沙运动数学模型,提出了一种对泥沙运动模型率定与验证的新思路,即采用代表潮和代表波浪场对长期水动力进行模拟,并利用具有统计意义的代表含沙量场对泥沙起动各参数进行率定,最后采用不同风浪条件下的含沙量实测数据对模型进行验证.以连云港地区为例,对这种新思路进行了检验.研究结果表明,这种率定/验证思路可有效应用于粘性泥沙运动和航道回淤的模拟中.在所建思路与模型基础上,对淤泥质海岸大风作用下的泥沙运动特征及进港航道回淤特性进行了研究.结论显示大风作用下的含沙量分布形式与正常天气相似,但含沙量数值大幅增高.一次大风对航道回淤的影响时间应为大风期间与风后一段时间的总和,其中航道回淤最强的时刻发生在风后一天左右,然后随时间推移而逐渐降低至正常天气状态.最后,根据模型预测,连云港地区进港航道不会发生一次大风骤淤碍航的情况.     

长江河口石洞口电厂扩建工程温排水三维数值模拟

采用改进的河口海岸海洋三维数值模式ECOM,考虑潮汐、径流、风应力和江表面热通量的作用,计算和分析石洞口电厂扩建工程夏季温排水的输运扩散.数值模式计算流速流向和实测资料符合良好,表明模式能较正确地模拟长江河口的水动力过程.模式计算结果表明,温排水分布在沿岸一带,受径流作用,下游受影响范围远较上游大.在本工程排水口附近,大潮和小潮平均温升分别为2.34和2.84℃,表层温升为1.0℃的面积分别为0.09和0.20 km~2,底层温升为1.0℃的面积均为0.09 km~2.大潮期间流速大,平流和侧向扩散作用大,造成大潮期间本工程排水口附近温升大小、温升沿岸扩展的范围和量值明显比小潮期间小.     

正规半日潮港湾中的潮汐余流环流

根据湄洲湾和厦门湾这二个正规半日潮港湾的实测海流资料,获得了这二个港湾中几个典型海区的表层、5m层和底层潮汐余流,从而描述了其分布特征,证实了在正规半日潮港湾中可存在多个潮汐余流环流,讨论了风、岸形和底形等因素对潮汐余流的影响。     

东京湾流场三维数值模拟

结合东京湾海水流动的特点，建立了求解其水流运动要素的三维数值模型。在模型中考虑了潮汐、风等的影响，沿水深方向可分成多层计算，定量地给出潮汐在各变化时刻的水流运动要素、潮位分布等。模拟计算结果表明计算值与实测值吻合很好。