南海浮游圆筛藻的分类研究

圆筛藻属的种类是南海近岸浮游植物中的优势种或习见种，又是海洋动物的直接或间接食物。近年来随着石油工业的迅速发展，发现在油田岩心样品中也保存着一些圆筛藻，因此有必要了解我国圆筛藻的种类和分布，供作我国资源开发的参考。 关于南海圆筛藻的分类研究，金德祥等报告过14种1变种。郭玉洁报告过圆筛藻属的5个新种。郭玉洁等报告过采自西沙群岛和中沙群岛及其附近海域的圆筛藻9种。本文主要报告采自广东省近海和北部湾东部的圆筛藻13种7变种，其中4种6变种在我国是首次记录，1种和1变种是世界新记录。到目前为止，在南海已记录圆筛藻24种7变种。 本文除对产自我国南海的圆筛藻的壳面特征进行绘图、描述和拍照外，并对其环面也进行了详细描述和绘图，以补充以往文献的不足。对于在西沙和中沙群岛及其附近海域已作过详细形态描述的种类如高圆筛藻(Coscinodiscus nobilis Gruu.)等，在此则不再重复。各种名下仅列出其原始定名文献和国内资料，对国外的一般性文献则从略。本文绝大部分种类的学名均根据科学出版社出版的《藻类名词及名称》(1979)。     

西沙、中沙群岛海域的角藻

角藻是甲藻门、甲藻纲、多甲藻目、角藻科的一个大属,在世界上已记录约120种,除个别种外,都是海产,主要分布在热带大洋及其附属海域。它们中的大多数对环境条件要求相当严格,因此其区系分布和生态特点在海洋学上具有重要意义。 截至目前,已发表的一些世界大洋的角藻分类和生态报告,除印度洋调査外,其余大都未涉及其边缘海域。在国内,曾报道渤海、厦门和海南岛水域的角藻32种,其调査区或在内海或距岸较近。西沙、中沙群岛海域的角藻则尚未见记载。 随着我国海洋调査范围向东部和南部外海发展,我们采到许多角藻标本。本文根据1974年5-6月和1975年3-4月,在西沙、中沙群岛及其附近海域(15°28''-17°30′N,111°10′-114°50′E)42个测站上,用网目为68平方微米的小型浮游生物网,自水底至水表垂直拖网所获得的材料,先报告角藻31种,其中有20种和4変种是我国初次记录(包括新订正的一个变种),其余种类以后陆续报道。 在西沙、中沙群岛海域的角藻中,除极少数可见于温带外,绝大多数都是热带海域的习见种;还有圆头形角藻(Ceratium gravidum Gourrct)、剑锋角藻(C. incisum (Karst.)(?rg)、曲肘角藻(C. geniculatum(Lemm.)Cleve)等世界罕见的狭热带性种,锥形角藻(C. schroeteri Schr?der)、梭角藻针状变种(C. fusus var.seta(Ehr.)J?rg)、偏转角藻(C.deflexum(Kof.)J?rg.)、毕氏角藻(C. bigelowii Kofoid)等热带印度-西太平洋特有种，以及深水产的嗜阴性物种,如脑形角藻(C.cephalotum (Lemm.)J?rg.)、长头形角藻(C. praelongum (Lemm.) Kofoid ex J?rg)等。它们分别代表着西沙、中沙群岛海域生物地理学和海洋生态学的特点。 本属有些种的形态变化很大,无论在文献或我们的标本中都出现许多这种现象。因此在本文中对一些多型种标本进行了详细测量,以便与其近缘种比较。J?rgensen曾提出本属的分类演化系统, Sournia对此也进行过讨论。目前我们对本属全部种类的形态和生态变异认识还不全面,故本文对每亚属内的物种暂按种名字母顺序排列描述,以后再进一步讨论其演化系统。     

Seagrasses from the Nansei Islands, Southern Japanese Archipelago: species composition, distribution and biogeography

The Nansei Islands in the southern Japanese Archipelago have 15 taxa of seagrasses from seven genera within three families. Seagrasses in this region grow on coral sands or coral debris in shallow reefs and on sandy or muddy substrata in the shallow areas of bays and inlets. Certain Halophila species grow in deep water off some islands. Enhalus acoroides only reaches to Ishigaki I. with winter sea water temperature (WST) at 23 °C, while Okinawa I. (WST at 21.6 °C) is the northern biogeographic limit for Halophila decipiens, H. okinawensis, H. major and H. gaudichaudii. Amami‐oshima I. (WST at 20.7 °C) is the northern border for Thalassia hemprichii, H. minor, H. ovalis, Cymodocea serrulata, Cymodocea rotundata, Syringodium isoetifolium, Halodule uninervis and Halodule pinifolia. Halophila mikii the sole seagrass collected from Yakushima I. (WST at 19.3 °C), is of volcanic origin. The distribution of tropical seagrasses in the Nansei Islands is clearly associated with the warm Kuroshio Current, WST and habitat availability. Zostera japonica is the only temperate species occurring in the region. Meadows of Z. japonica, H. ovalis and Halodule pinifolia have disappeared from certain localities in the Archipelago, due probably to human activities and natural siltation.     

Comparison of Sea Surface Heights Derived from Satellite Altimetry and from Ocean Bottom Pressure Gauges: The SW Pacific MOTEVAS Project

A bottom pressure gauge (BPG) was installed in proximity (3.7 km at closest approach) of Jason-1 and formerly TOPEX/Poseidon (T/P) ground track No. 238 at the Wusi site, located ∼ 10 km offshore off the west coast of Santo Island, Vanuatu, Southwest (SW) Pacific. Sea level variations are inferred from the bottom pressure, seawater temperature, and salinity, corrected for the measured surface atmospheric pressure. The expansion of the water column (steric increase in sea surface height, SSH) due to temperature and salinity changes is approximated by the equation of state. We compare time series of SSH derived from T/P Side B altimeter Geophysical Data Records (GDR) and Jason-1 Interim Geophysical Data Records (IGDR), with the gauge-inferred sea level variations. Since altimeter SSH is a geocentric measurement, whereas the gauge-inferred observation is a relative sea level measurement, SSH comparison is conducted with the means of both series removed in this study. In addition, high-rate (1-Hz) bottom pressure implied wave heights (H_1/3) are compared with the significant wave height (SWH) measured by Jason-1. Noticeable discrepancy is found in this comparison for high waves, however the differences do not contribute significantly to the difference in sea level variations observed between the altimeter and the pressure gauge. In situ atmospheric pressure measurements are also used to verify the inverse barometer (IB) and the dry troposphere corrections (DTC) used in the Jason IGDR. We observe a bias between the IGDR corrections and those derived from the local sensors. Standard deviations of the sea level differences between T/P and BPG is 52 mm and is 48 mm between Jason and BPG, indicating that both altimeters have similar performance at the Wusi site and that it is feasible to conduct long-term monitoring of altimetry at such a site.     

高光谱吸收特征参数反演草地光合有效辐射吸收率

在植被光合有效辐射吸收率(FAPAR)遥感估算中被广泛采用的植被指数法,其估算精度往往受到"红波段吸收峰"峰值点光谱反射率易饱和特征的影响。考虑到高光谱吸收特征参数能较好地诠释地物光谱吸收特征的细节信息,基于微分法与包络线去除法研发"高光谱曲线特征吸收峰自动识别法"识别对FAPAR敏感的特征吸收峰,再结合连续统去除法以及光谱吸收指数(SAI)提取FAPAR的高光谱吸收特征参数,构建估算天然草地冠层水平FAPAR的高光谱吸收特征参数模型。结果表明:(1)天然草地冠层FAPAR与高光谱吸收特征参数具有很好的相关性,其中,"红波段吸收峰"SAI对FAPAR变化最为敏感,在植被覆盖度较高时,其饱和性相比"红波段吸收峰"峰值点反射率与归一化植被(NDVI)值有较大的提升。(2)以"红波段吸收峰"SAI为变量的对数方程为FAPAR的最佳估算模型,在植被覆盖度处于中与高时,其FAPAR预测精度比NDVI模型有不同程度的提高。研究采用的高光谱吸收特征参数一定程度上弥补了部分植被指数因饱和问题在估算FAPAR时的不足,可作为植被FAPAR反演的新参数,适用于中、高覆盖度的天然草地FAPAR监测。     

Vortex boundary layer under quadratic surface stress

The influences of the quadratic surface stress on the two-dimensional structure of boundary-layer flows in hurricane-like and tornado-like vortices are investigated by solving the nonlinear boundary-layer equations in the vertical direction through power series expansion and expressing the expansion coefficients in terms of parameters of the vortex profile. It is found that the series solutions converge rapidly and the vertical velocity w_bcreated by the boundary-layer flow is upward everywhere for the hurricane type vortex, with the maximum vertical velocity w_bmoccurring inside the radius of maximum tangential wind. This result is of utmost importance for the hurricane development problem on account of the organizing influence of w_bon cumulus convection and latent heat release in the conditionally unstable tropical atmosphere. On the other hand, the vertical velocity created by the boundary layer of the pure potential vortex with zero absolute vorticity is downward.     

Inflow and outflow in a rotating circular container—A laboratory model for the Loop Current of the Gulf of Mexico

The Loop Current of the Gulf of Mexico is simulated in the laboratory. A circular tank is filled with water and is placed off-center on a rotating table and the flow field is generated by injecting and withdrawing water at two openings on the wall. The free surface becomes parabolic due to balance of gravitational and centrifugal forces, simulating the latitudinal change of the Coriolis parameter (-effect) in the ocean. The flow characteristics depend on the influx and the rate of rotation and can be classified according to non-dimensional parameters (Rossby, Ekman and Froude numbers denoted byR ₀,E andF, respectively). When the influx is small and the rotation rate is large (smallR ₀,E andF) the flow will be almost linear, and the fluid flows along the side-wall boundary layer under constraint of the -effect. For a very large influx (largeR ₀ andE) inertial forces become very large compared to the Coriolis force and the flow behaves like a potential flow. The flow studied had characteristics between these two extreme cases and hasR ₀ andF similar to the Gulf circulation, though similarity inE is ambiguous. Photographs of the flow indicate that the inflow penetrates further into the interior when the rotation rate is increased while the influx is kept constant. The numerical analysis of the non-linear vorticity equation confirms this for the parameters corresponding to the experiment. In addition, the photographs reveal eddies embedded on both sides of the main stream, particularly near the inflow region. These eddies are intensified and become uniform in size as the influx increases. It is pointed out that such eddies were actually observed near the Loop Current north of the Yucatan Straits.     

Gravity change in the Beijing-Tianjin-Tangshan area

A gravity network was established by a crew of gravity measurement in July, 1981, with three LCR gravimeters. The measurement errors are less than 100 nm/s². The detectable changes in gravity with time in the Beijing-Tianjin-Tangshan area are described. The results show that the gravity has increased 1000 nm/s² in Tianjin area where the ground has been subsiding at a rate of 7–8 cm/a and at the center of subsidence gravity has increased. At other stations, such as Baodi, Tangerli, etc., gravity has also increased gradually, but with an amplitude smaller than that of Tianjin. In the area surveyed gravity tendentiously decreases from south-east to north-east.     

Treatment of groundwater contaminated with high levels of explosives using advanced oxidation processes

Current and former military installations around the world have numerous sites with groundwater contaminated with explosive compounds polluted from military related activities. The test influent used in this study was a groundwater collected from an US Army facility that was contaminated with high levels of military derived explosives. The sample had a total explosive concentration in excess of 75 mg/l. Bench-scale evaluations were performed to determine the effectiveness of the candidate advanced oxidation processes for treatment of the groundwater in terms of removing the pollutants to method sub-detection limits with these results formulating the basis for comparison along with generating data that can be used toward increasing the understanding of treatment mechanisms associated with the various processes. Results indicate that the ozonated systems generally resulted in the removal of the explosives to the targeted levels with 1,3,5-trinitrobenzene removal lagging in terms of removal due to its simultaneous formation and degradation. The oxidation system that was irradiated using the medium-pressure UV lamp and dosed with hydrogen peroxide and ozone achieved the best performance with complete removal of all targeted pollutants within 10 min of treatment.