Deep-water transit times in the eastern Indonesian basins,calculated from dissolved silica in deep and interstitial waters

The flushing of the deep basins in the eastern Indonesian archipelago is studied by means of the dissolved silica (Si) distribution, using water column data from the Snellius-II Expedition as well as from the Indopac Expedition. The linear θ-Si relationships below 500 to 1000 m permit the use of Si as a water-mass tracer. The main outflow of deep water from the Banda Sea into the Timor Trench is found east of Timor, above 1250 m depth, and the deeper parts of this outflow are partly recirculated through the Aru Basin and the Seram Sea into the north Banda Sea. Below the sill depth of the various basins, θ remains about constant while Si gradually increases towards the bottom. The time needed to create this Si-excess is obtained with the Si-flux out of sediments, calculated from pore-water gradients. Deep-water transit times are 20 years for the Banda Sea, 2 to 15 years for smaller basins and 60 years for the intermittently flushed Weber Deep. Modelling the Si-excess with error functions in some small basins gives high diffusion coefficients of 45 to 150 cm²·s⁻¹. The flux of Si from the sediments, 0.5 to 2 mol·m⁻²·a⁻¹, is higher than in other deep-sea basins, it amounts to roughly 30% of the biogenic silica production in the euphotic zone. Dissolved Si at 20–40 cm depth in the sediments ranges from 450 to 590 mmol·m⁻³; about 2% of Al in biogenic silica from sediments might cause this apparently low solubility for sediments rich in biogenic silica.     

Organic carbon in the upper 100 m and downward flux in the banda sea; monsoonal differences

Organic carbon was measured in the upper 100 m and its downward flux from the euphotic zone recorded, as part of a multidisciplinary study in the Banda Sea on monsoonal differences in the upper water layers.All 35 stations occupied showed on average 1.5 times higher POC values in August 1984 (4.9 g·m⁻², SE monsoon, upwelling period) than in February/March 1985 (3.3 g·m⁻², NW monsoon, downwelling period) for the 0 to 100 m water column. Monsoonal variation in POC was confined to the surface layer and related to a variation in phytoplankton content; it can be explained by — local— upwelling during the SE monsoon. At 100 m no seasonal variation occurred.Contrary to POC, average figures for DOC in February/March were almost twice the average observed in August (66.5 against 37.5 g·m⁻² for the 0 to 100 m water column). In February/March spatial variation was more pronounced than in August with highest values occurring in the NE part (>100 g·m⁻², 0 to 100 m), with a subsurface maximum. In this period the NW monsoon causes a surface current to the east. This might cause a westward subsurface countercurrent of Arafura Sea water rich in riverine or benthic layer DOC, influencing the eastern Banda Sea.At 100 m depth daily sedimentation amounted to ∼50 mg C·m⁻². The limited number of data do not indicate a difference between the 2 periods. On average the daily downward flux at 100 m depth amounted to 1.2% of POC and 0.8% of chlorophyll present in the 0 to 100 m water column, and equalled 5% of the daily primary production.     

Monsoonal alternation of a mixed and a layered structure in the phytoplankton of the euphotic zone of the banda sea (Indonesia): a mathematical analysis of algal pigment fingerprints

The chlorophyll a concentration of the upper 25 m of the euphotic zone of the Banda Sea was 5 times higher in August 1984, in the upwelling season during the southeast monsoon, than in February 1985, during the northwest monsoon when a deep chlorophyll maximum layer was presented at 40–80 m. Similarity between stations was calculated by means of a cluster analysis of the concentrations of 4 different chlorophylls and 6 carotenoids. High similarity over large areas, one to the west and one to the east of the Banda Arc, is evidence of the importance of large-scale phenomena influencing the phytoplankton during the monsoons. All samples taken in the deep chlorophyll maximum layer during the northwest monsoon were clustered as a separate group.Multiple regression analysis of chlorophyll a and the four most important accessory pigments suggests that in August 1984 (upwelling season) the fucoxanthin-containing group (mainly diatoms) contributed 50% to the chlorophyll a in the euphotic zone; green algae and Prymnesiophyceae contributed each 20%, Cyanobacteria only 9%. In February 1985, during the downwelling season, pico- and nanoplankton containing 19'-hexanoyloxyfucoxanthin (Prymnesiophyceae) and zeaxanthin (Cyanobacteria) each contributed 40% of total chlorophyll a, both near the surface and in the deep chlorophyll maximum layer; 19'-butanoyloxyfucoxanthin (a marker of certain Prymnesiophyceae and Chrysophyceae) was only present at depth. On the assumption that Chl. b is a pigment confined to green algae, this group contributed 14% of the Chl. a in the deep maximum. Other green-algal pigments were, however, scarce at depth (lutein, violaxanthin), which suggests presence of Prochlorophyta.Shifts in pigment ratios (zeaxanthin : Chl. a; Chl. b : Chl. a), probably related to light adaptation, hinder the use of algal pigment fingerprints for estimating quantitative composition of natural phytoplankton; indeed, differences between samples in pigment signature can have both a floristic and an ecophysiological background. Statistical analysis of pigment fingerprints may further be complicated due to presence of intermediates of pigment synthesis and breakdown, and poor taxon specificity of fucoxanthins and possibly even of Chl. b and zeaxanthin.     

Physical aspects of the flushing of the east Indonesian basins

The flushing of the deep basins in the east Indonesian archipelago is studied by means of water mass analysis, current observations and simple theoretical models. The Banda Sea and its secondary basins appear to be flushed from the Pacific Ocean with a typical flushing time of the order of 40 years. This fast flushing is made possible due to the high vertical diffusivity which is estimated to be of the order of 10⁻³ m²·s⁻¹. Theoretical models to descrive the vertical distribution of tracers due to mixing and basin wide upwelling turn out to fit the data very well. The observations cannot be used to confirm the horizontal structure of the deep circulation which results from a simple β-plane model. The vertical structure of the Aru Basin and the Timor Trench is more complicated due to the presence of water from the Indian Ocean, the Pacific Ocean and the Banda Sea. But also here simple models can be applied.     

浅圆仓环流熏蒸磷化氢气体在粮堆内分布规律的研究

通过对较大型浅圆仓环流熏蒸后,粮堆内不同深度的磷化氢气体浓度的跟踪监测,了解磷化氢气体在粮堆内不同部位的浓度分布及变化特征,分析造成磷化氢气体在粮堆内的不同部位浓度不均的原因,从而为浅圆仓环流熏蒸提供依据。     

磷化氢环流熏蒸技术在高大房式仓中的应用

在高大房式仓中进行了磷化氢环流熏蒸试验，同时研究了不同仓型和不同熏蒸方式存在的差异。结果表明，在仓房容量、风道设置、环流设置配置合理的条件下，能在较短时间内使磷化氢气体在仓内各部位分布均匀，最低浓度与最高浓度比值最小为0．5，大部分比值在0．8－0．9之间，均高于国外资料推荐的PH3环流熏蒸浓度均匀性标准，即大于0．25。保持有效杀虫浓度的时间长，能够杀死仓内粮堆中的储粮害虫，取得了良好的杀虫效果。     

Evaluation of seasonal nutrient dynamics in the oosterschelde (SW Netherlands)

A large set of data obtained from several monitoring programmes covering more than 3 years of registration of environmental parameters in the Oosterschelde estuary were used to evaluate seasonal trends in dissolved nutritive compounds. The deviations from conservative behaviour were calculated. It is concluded that specific estuarine processes rule the distributions of nitrogen compounds within the estuary and that these processes are largely dependent on the input of organic material from the sea. Levels of silica are almost completely governed by fresh water discharges throughout the year, except for the Keeten-Krammer area in spring. Phosphorus concentrations are steady throughout the year with minor influences of exchange with sediment in spring and summer and an influence of the North Sea in spring.     

不同利用方式对紫色水稻土水溶性有机碳的影响

通过研究西南大学试验农场包括不同的耕作、轮作和施肥的综合利用方式对经14年28茬的紫色水稻土水溶性有机碳的差异，探究利用方式对水溶性有机碳的影响。结果表明：0~30cm土壤水溶性有机碳变化范围在30.3~339.8mg/kg，热水提取的水溶性有机碳变化范围在60.9~740.2mg/kg，两种方法提取的有机碳随深度增加而降低。长期垄作并实行稻油轮作的利用方式使土壤水溶性有机碳在0~30cm土层与其他利用方式相比明显增加，并且差异显著；而水旱轮作（稻油）利用方式下的水溶性有机碳含量最低。水溶性有机碳可用作评价利用方式对紫色水稻土质量变化影响的有效指标。从提高土壤水溶性有机碳含量的角度来看，垄作并实行稻油轮作的利用方式比较适合紫色水稻土     

甲基嘧啶磷气化防治储粮害虫试验

在不同磷化氢环流熏蒸设备配置条件下采用气化施药法在粮堆中施用甲基嘧啶磷防治储粮害虫。试验结果表明:气化施药法可以使储粮保护剂在粮堆中具有一定的穿透能力,但在粮堆上下层的浓度相差较大,在环流系统效率较好的情况下,粮堆上层1 m多的粮层中药剂浓度可达到全仓平均施药浓度以上。     

A comparison of condition indices of Macoma Balthica (L.) from the northern and southern baltic sea

Geographical differentiation and seasonal variations of two morphological condition indices (Cl₁ = shell-free dwt/shell dwt in mg·g⁻¹ and Cl₂ = shell-free dwt/shell length³ in mg·mm⁻³), and lipid and glycogen content (% of the shellfree dwt) of adult individuals of the bivalve Macoma balthica (L.) were studied from two different areas of the Baltic Sea. Within each area (the Åland Archipelago in the north and the Gulf of Gdansk in the south) a microgeographic gradient is described to illustrate local variations in the parameters measured.For the regions and stations studied, population structure (numbers and size distributions) was very different. Slight differences in the time of onset of spawning (March-early May in the south, and late April-May in the north) were observed between the two areas studied.Both the morphometric indices used showed a strong age-(size) dependence, changing seasonally and microgeographically within each region (in the Gulf of Gdansk Cll₁-values ranged from 100 to 400, and Cl₂ from 6 to 25 during 1981). The lipid content in both areas generally increased with depth (on Åland from 14.7% at 1 m and 19.0% at 3 m to 24.3% at 20 m depth in July 1986). Increased values of both lipid content and Cl₂ at the deepest stations sampled (20 m in the north, and 75 m in the south) may suggest differences in trophic conditions, illustrating better average nutritive conditions for the adult bivalves.It is concluded that the condition indices used in this study give a sound illustration of the state of the populations studied, and a valuable contribution to the interpretation of the state of animal communities in different regions of the Baltic Sea.     

The European regional seas ecosystem model,a complex marine ecosystem model

This paper presents an overview of the concept, structure and implementation of the European Regional Seas Ecosystem Model (ERSEM). The model dynamically simulates the biogeochemical seasonal cycling of carbon, nitrogen, phosphorus and silicon in the pelagic and benthic food webs of the North Sea, and is forced by irradiance, temperature and transport processes.The model has a coarse spatial resolution into ten boxes, the ICES boxes, of which the five deepest have been resolved into surface (0 to 30 m) and deep (30 m to bottom) boxes.At the open boundaries, time series are prescribed for dissolved and particulate nutrients. River loads of nutrients for the rivers discharging into the North Sea are prescribed at monthly intervals. A general circulation model has been used to aggregate the exchange volumes across the box boundaries into daily in- and outflows. From these, the horizontal transports of dissolved and suspended constituents are calculated. Vertical transport is in the form of sinking and sedimentation for particulates and in the form of turbulent diffusion for dissolved constituents.The physical model contains all information specific to the area to be modelled, whereas the biological/chemical submodels have been constructed not to be site-specific.The biological variables are represented as functional groups expressed in units of organic carbon and the chemical variables as the internal pools in the biological variables and as the dissolved inorganic pools in water and sediment, expressed in units of N, P and Si.The model runs in a software environment (SESAME) developed for enabling the development of large and complex models in a modular way by a consortium of institutes, each focusing on different. aspects of the ecosystem, translating these into modules within the model. With the exception of fish populations, where size- and age-structure are explicity represented, all the other biological components have been modelled as unstructured populations aggregated into functional groups. This approach is shown to be appropriate for taxa having short generation times in relation to the annual cycle and for taxa which do not span more than one trophic level during their lifetime.     

膜下环流熏蒸对抗性储粮害虫的防治效果

在1458m^3和6000m^3粮堆中进行了环流熏蒸试验。结果表明，采用膜下环流熏蒸可有效提高仓房的气密性，取得良好的熏蒸杀虫效果。     

土堤仓储粮磷化氢环流熏蒸工艺与应用

在堆高7 m、容量1858万千克的大型储藏小麦的土堤仓内和土堤仓底设置PVC磷化氢环流管道,采用外设环流风机环流促使仓内磷化氢均匀分布,检测浓度分布情况、杀虫效果和粮食品质变化.结果表明,仓内磷化氢浓度最低保持在300 mL/m3以上的时间可达25 d,浓度在250 mL/m3以上的时间迭34 d,粮堆中发生的书虱、锈赤扁谷盗等害虫均被完全杀死,试验的熏蒸工艺对粮食品质及粮堆内温度影响很小.     

Distribution,organic content and particle size of suspended matter in the north sea

Data on suspended matter concentrations and the organic content of the suspended matter for January 1980 showed a division in the North Sea between the southern North Sea (high suspended matter concentrations, but relatively low organic content) and the central and northern North Sea (low suspended matter concentrations, but relatively high organic content). The Skagerrak, which receives suspended matter from the southern as well as from the central and northern North Sea, took up an intermediate position.In summer suspended matter concentrations were lower than in winter but more variable, in concentration as well as in organic content, because of admixtures of particulate matter from primary production. On deposition of the suspended matter, a considerable part of the organic matter was apparently lost (in the order of 75% or more), resulting in low organic-matter concentrations of fine-grained bottom deposits.Particle-size distributions followed two main types: one (A) with a sharp peak at 30 to 100 μm, and one (B) bell-shaped with a peak at 5 to 15 μm. Type A occurred in deeper water and consisted of particles with a high organic-matter content, type B occurred in shallow areas and consisted of particles with a low organic-matter content. The suspended particles were mainly microflocs of mineral particles and organic matter. The mineral particles of both types were predominantly of 2 to 5 μm size, which was determined after oxidation of the organic matter. It is concluded that particles of type-B distributions are regularly exchanged with the bottom through deposition and resuspension, which results in low organic-matter contents and prevents the microflocs reaching large sizes. Paricles of type-A distributions, on the contrary, can reach much larger sizes, because mostly they remain in suspension and do not lose organic matter, so that they do not easily fall apart.     

新型平房仓环流熏蒸系统环流效果的研究

对我国新建平房仓的固定式和移动式两种环流装置进行了实仓环流效果的试验研究，结果表明，新建平房仓的环流熏蒸系统可使磷化氢气体在较短的时间内穿过深层粮堆，一般可在施药开始后8-17小时内使磷化氢气体在全仓达到均匀分布。上层和空间的磷化氢浓度达到均匀一致即表明整个粮堆浓度达到了均匀分布。同时发现，通风道的形式及平衡调节、粮堆内的温差及仓房的气密性都会影响环流效果。     

Input of selected chlorinated hydrocarbons into the coastal area of East Java and adjacent waters: Distribution patterns in the dissolved and suspended phase

Selected organochlorines were analysed in water and suspended particulate matter collected at stations in two rivers on East Java, the adjacent coastal zone, the Java Sea and the Indian Ocean. The sampling period covered the dry monsoon and the beginning of the wet monsoon. Concentrations of dissolved polychlorinated biphenyls (PCBs) were in the same range as in Western Europe and North America. In contrast, the concentrations of all measured organochlorines in suspended matter were lower and often not detectable.p,p′-DDT and its metabolites p,p′-DDD and p,p′-DDE showed the highest concentrations of all compounds determined. The rivers Bengawan Solo and Kali Porong can be considered sources of these compounds for the coastal environment, although their impact is restricted to a small area.Significant differences between the dry and wet monsoon were only observed for dissolved PCBs in the river Porong.     

Trace oxyanions and their behaviour in the rivers Porong and Solo,the Java Sea and the adjacent Indian Ocean

During the Snellius-II Expedition (theme 5) dissolved and particulate concentrations of As(III), As(V), Sb(III), Sb(V), Se(IV), Mo, U, V, Au and W were measured in the Kali Porong and Bengawan Solo, Strait Madura, the Java Sea and the adjacent Indian Ocean.The estuarine mixing behaviour of Mo, U and V was found to be conservative. Arsenic behaved in a conservative manner during the wet period, while removal was observed in the high salinity region of the Solo and Porong during the dry season. The exceptionally high vanadium concentration in the rivers Porong and Solo, which is more than 10 times higher than that in the world rivers, is connected with leaching of volcanic rock; dissolved concentrations of Au, W and Mo are also higher. Apart from V and Au, the dissolved concentrations in the Java Sea and in the Indian Ocean compare well with average ocean values.     

高大平房仓PH3低剂量环流熏蒸杀虫试验

用仓外移动式环流熏蒸装置在高大平房仓中一次性施用磷化铝片剂1g/m^3、二氧化碳25g/m^3进行熏蒸杀虫，结果表明：仓内各部位磷化氢浓度分布均匀，密闭388个小时，仍保持有效浓度100ppm，杀虫效果100％；且具有省工省时、操作简便、安全经济的特点，是用于高大平房仓的一种效果好、经济效益显著的杀虫方法。     

老式高大平房仓环流熏蒸应用报告

在没有配备通风道不能进行环流熏蒸的原建高大平房仓内，在原来粮堆预埋PVC管进行仓外PH3与CO2混合投药熏蒸的基础上，通过在墙上安装回流管的办法，采用AlP粮面投药自然潮解进行环流熏蒸，保证了PH3有效浓度在整仓内的均匀分布，取得了良好的杀虫效果。     

季节性冻融期不同地下水位埋深下土壤温度变化特征

土壤温度是土壤热状况的综合表征指标,影响土壤养分分布和冬春季节作物生长发育。以山西省水文水资源勘测局太谷均衡实验站为试验基地,对冻融期4种不同地下水位埋深下的土壤温度进行了分析研究。结果表明：在地下水浅埋区,冻融期地温的变化滞后气温变化,且滞后时间随土壤深度的增加而增大。12月初-2月下旬,地下水位为1．0m埋深的土壤温度较高;消融期地下水位为1．5m埋深下的土壤温度迅速回升。而0．5m埋深下的土壤温度较低且回升较慢;同一地下水埋深下,随着土壤深度的增加。剖面温度增高。50cm深度之下的土壤温度受地下水位埋深的影响较弱。研究成果可为冬春作物播种、预防冻害提供参考依据。