天目山千亩田泥炭腐殖化度记录的中全新世气候变化

以14C测年为基础,构建了天目山千亩田地区泥炭沼泽剖面年龄-深度模式曲线,通过该区的腐殖化度与烧失量分析研究,发现两者呈现出很好的相关性,共同记录了该地区4 200 aBP以来的气候变化,可划分出3个主要阶段:早期(4 135±40~3 200 aBP)泥炭腐殖化度偏低,指示气候湿热;中期(3 200~630 aBP)泥炭腐殖化度偏高,指示气候温凉偏干;晚期(630 aBP以来),泥炭腐殖化度偏低,气候温凉湿润。     

Physiological aspects of the production and conversion of DMSP in marine algae and higher plants

Dimethylsulphoniopropionate (DMSP) is a compound produced in several classes of algae and higher plants that live in the marine environment. Considering its generally high intracellular concentrations, DMSP has a function in the osmotic protection of algal cells. Due to the relatively slow adaptation of its intracellular concentrations upon salinity shifts, DMSP should, however, not be considered as an osmoticum in the strict sense of being responsible for osmotic balance, but rather as a constitutive compatible solute. Besides salinity, other factors also appear to affect cellular DMSP quotas, but the exact regulatory mechanisms are still unclear. In this review, a brief discussion is given of the three pathways of DMSP biosynthesis that are currently distinguished. This is followed by an overview of the factors that affect DMSP biosynthesis (light, salinity, temperature and nitrogen limitation) in relation to its physiological functions. A new hypothesis is presented in which DMSP production is described as an overflow mechanism for excess reduced compounds and for energy excess. Finally, the possible functionality of the enzymatic cleavage of DMSP is discussed in the context of an overflow mechanism.     

Emerging coral diseases: a temperature‐driven process?

In the last few decades there has been a surge in research focusing on coral disease. While climate change, specifically rising sea surface temperature, has been proposed as a major and growing driver of the emergence of marine diseases, to date a solid connection between disease epizootics and elevated sea surface temperature has not been established. However, a wealth of data now exists, compiled from many different perspectives, that may support such a connection. In this work we provide a comprehensive review targeting one coral disease, black band disease, that spans the infection process, pathobiology, and epizootiology, and links specific mechanisms of the disease process to increasing temperatures. This temperature‐driven pattern of infection can be expanded to include similar processes associated with other temperature‐related coral diseases. The conclusions presented here are based upon the results of many studies using a diverse suite of approaches that have been synthesized to argue that the emergence and continuing spread of black band disease is linked to warming sea surface temperatures. In summary, as global ocean temperatures increase seasonally and over decades, the environment shifts to become more favorable for the growth of potentially pathogenic microorganisms endemic to the immediate environment of the reef. The increase in the relative number of potential pathogens in the microbial community produces microenvironments conducive to the growth of other potential pathogens, leading to infection by a polymicrobial consortium. This consortium is easily perturbed by a (seasonal) temperature decrease, but remains associated with the coral host and can be reactivated with a subsequent seasonal increase in temperature, resulting in a cycle of temperature‐dependent disease emergence.     

鲐鱼灯光围网渔船水上集鱼灯水中照度分布及优化配置的理论计算

采用叠加法照度计算模式,根据一组鲐鱼灯光围网渔船中3艘不同渔船的水上集鱼灯布置参数,使用自行开发的水上集鱼灯水下光场计算系统,对各船的水中照度分布进行了计算,获得船舷右侧中部水深方向200 m范围内不同深度的照度,并使用Surfer 8.0软件绘制等值曲线图,结果表明:主灯船在总功率为180 kW的情况下,10 lx的等照度曲线水平方向最远在56 m左右,水深方向不超过20 m;离船水平距离40 m、垂直距离40 m处的照度约为0.01 lx。副灯船在总功率为120 kW的情况下,10 lx的等照度曲线水平方向最远在46 m左右,水深方向不超过18 m;离船水平距离33 m、垂直距离38 m处的照度约为0.01 lx。网船在总功率为40 kW的情况下,10 lx的等照度曲线水平方向最远在45 m左右,水深方向不超过15 m;离船水平距离30 m、垂直距离35 m处的照度为0.01 lx左右。从集鱼灯的配置情况来看,主灯船、副灯船与网船目前的配置均较好,但主灯船在灯距增大到0.26 m、灯高增大到5 m时可增加1.6%的有效水体体积,副灯船在灯距减少到0.28 m、灯高增大到5 m时可增加2.1%的有效水体体积,网船在灯距增大到0.64 m、灯高增大到9 m时可增加1.7%的有效水体体积。计算结果还表明,大幅度的增加光诱渔船的集鱼灯功率并不能很有效的提高该船的光诱范围。     

The effect of the wave-induced mixing on the upper ocean temperature in a climate model

The significant underestimation of sea surface temperature （SST） and the temperature in the upper ocean is one of common problems in present climate models. The influence of the wave-induced mixing on SST and the temperature in the upper ocean was examined based on a global climate model. The results from the model coupled with wave-induced mixing showed a significant improvement in the simulation of SST and the temperature in the upper ocean compared with those of the original model without wave effects. Although there has still a cold bias, the new simulation is much closer to the climatology, especially in the northern ocean and tropical ocean. This study indicates that some important physical processes in the accurate simulation of the ocean may be ignored in present climate models, and the wave-induced mixing is one of those factors. Thus, the wave-induced mixing （ or the effect of surface waves） should be incorporated properly into climate models in order to simulate or forecast the ocean, then climate system, more accurately.     

“Trends” and variations of global oceanic evaporation data sets from remote sensing

The variability in global oceanic evaporation data sets was examined for the period 1988-2000. These data sets are satellite estimates based on bulk aerodynamic formulations and include the NASA/Goddard Space Flight Center Satellite-based Surface Turbulent Flux version 2 （ GSSTF2）, the Japanese-ocean flux using remote sensing observations （J-OFURO）, and the Hamburg Ocean-Atmosphere Parameters and Fluxes from Satellite version 2 （HOAPS2）. The National Center for Environmental Prediction （NCEP） reanalysis is also included for comparison. An increase in global average surface latent heat flux （SLHF） can be observed in all the data sets. Empirical mode decomposition （EMD） shows long-term increases that started around 1990 for all remote sensing data sets. The effect of Mt. Pinatubo eruption in 1991 is clearly evident in HOAPS2 but is independent of the longterm increase. Linear regression analyses show increases of 9.4%, 13.0%, 7. 3%, and 3.9% for GSSTF2, J-OFURO, HOAPS2 and NCEP, for the periods of the data sets. Empirical orthogonal function （EOF） analyses show that the pattern of the first EOF of all data sets is consistent with a decadal variation associated with the enhancement of the tropical Hadley circulation, which is supported by other satellite observations. The second EOF of all four data sets is an ENSO mode, and the correlations between their time series and an SO1 are 0.74, 0.71,0.59, and 0.61 for GSSTF2, J-OFURO, HOAPS2, and NCEP in that order. When the Hadley modes are removed from the remote sensing data, the residue global increases are reduced to 2.2% , 7. 3%, and 〈 1% for GSSTF2, J-OFURO and HOAPS, respectively. If the ENSO mode is used as a calibration standard for the data sets, the Hadley mode is at least comparable to, if not larger than, the ENSO mode during our study period.     

Summer light‐trap catches of adult Trichoptera in hill‐country catchments of contrasting land use,Waikato, New Zealand

The distribution of adult Trichoptera in light traps was investigated alongside nine streams draining catchments under native forest, pine forest, or pasture near Hamilton, Waikato, New Zealand. The aim of the study was to determine the relationship between abundance, taxonomic richness, and community composition with respect to land use during summer, and to evaluate the use of adult Trichoptera compared with benthic invertebrates as potential bio‐indicators of the effectiveness of land‐management changes. Adult Trichoptera faunas alongside the native streams were dominated by Hydrobiosidae, Conoesucidae, and Helicopsychidae (each >10% of total Trichoptera numbers for at least two of the three sites), whereas Leptoceridae, Oeconescidae, and Hydrobiosidae were relatively abundant alongside at least two of the pine sites. Adult Trichoptera faunas at the pasture sites were strongly dominated by Hydroptilidae which made up 47–85% of numbers caught at all sites. The mean number of individuals and taxa caught in light traps increased from November to January and then declined in February for all land‐use types. Overall, total numbers and taxonomic richness of adult Trichoptera were significantly lower at the pine sites compared to the pasture or native sites. TWINSPAN classification of benthic invertebrates collected in November clearly differentiated sites based on land use for presence/absence and percentage abundance data. A similar pattern was evident for most sites when adult Trichoptera faunas were used for the four sampling dates combined, suggesting that light trapping has potential as a tool for bio‐monitoring.     

Enhalus acoroides responses to experimental shoot density reductions in Haad Chao Mai National Park,Trang Province,Thailand

The effect of self‐shading and competition for light in the seagrass Enhalus acoroides were investigated with a density reduction experiment in Haad Chao Mai National Park, Trang Province, Thailand. The study was carried out in a monospecific meadow with a natural density of 141.0 ± 8.7 shoots·m^?2. The intent was to determine the response of E. acoroides beds to loss of shoots and thinning, which often occur during typhoons and severe storm activity. Permanent quadrats were manipulated by clipping the seagrass shoots to 140, 72, 36 and 16 shoots·m^?2, to yield natural, 50%, 25% and 10% densities, respectively. Reducing shoot density in E. acoroides increased underwater light intensity below the canopy, generating increased leaf surface area and shoot weight. Seagrass leaf width, growth rate, and number of leaves per shoot also increased with greater light. The extent of flowering varied among treatments with no consistent trend. Our results demonstrate that increasing the available light to E. acoroides produces an increasing leaf size response as self‐shading in the bed is reduced.     

渤海油田轻质油气藏气测流体评价方法

渤海油田中深层轻质油气流富集,原油密度小,气油比高,普遍处于气液同存的的交错相态。由于轻质油、气层荧光、气测等录井特征相似,加之部分井眼条件差,测井资料不完善,造成流体识别难度大。对目前常用的气测录井系统开展轻质油气藏流体性质评价研究发现,基于常规气测组分(C1—C5)的3H组合模型呈现一定的规律性,但与传统解释模型存在差异,结合星型图流体相分析法,可有效识别渤海油田PL7区块凝析气与轻质油,流体界面明显。对于FLAIR气测录井系统,针对测量组分(C1—C8)引入能够敏感反映油气丰度变化的气指数、油指数和水指数3个流体指数,依据这3个流体指数的纵向组合形态和变化趋势,可准确识别油气性质,对渤海油田轻质油气藏的流体评价优势明显。该研究促进了所在区块油气分布格局和储量的落实,在其他钻遇轻质油气流的区块具有较高的推广应用价值。     

离子迁移谱现场观测渤海和北黄海二甲基硫的研究

渤海、黄海是高产二甲基硫（Dimethyl Sulfide, DMS）的大陆架海区。该海区DMS的现场调查研究有助于准确评估海洋DMS释放量及其对全球气候变化的负反馈作用。目前,无论是基于模型还是直接测量法的通量估算均以表层海水或低层大气DMS浓度为基础,因此,先进的检测技术对其通量估算的准确度具有决定性作用。气相色谱法、质谱法、化学发光法以及卫星遥感技术是现在常用的观测技术,而本文则基于苯辅助光电离离子迁移谱技术进一步提出了一种可在海域现场观测海水中DMS的方法。通过结合动态气提-Nafion管在线除水进样系统,消除环境水汽的干扰;在最优条件下,基于DMS两个产物离子峰,可以实现0.10～120 nmol/L之间DMS的定量分析,检测限低至0.065 nmol/L;然后将所建方法应用于2019年秋季渤海、北黄海海水中DMS的现场观测。结果表明,表层海水中DMS的浓度为0.080～0.96 nmol/L（平均值为（0.44±0.34）nmol/L）,其海气通量为0.12～17.75 μmol/（m²·d）（平均值为（ 3.23±4.02）μmol/（m²·d））;通过结合实验室检测结果、环境因子和浮游植物群落结构讨论了海水样品低温储存条件下DMS的变化和影响因素,结果显示,营养盐成分及浮游植物群落结构是影响储存样品中DMS浓度显著增加的主要因素,进一步表明了现场观测方法的建立对海洋DMS释放量的准确评估具有重要意义。