ALBERT

Description: The rich fossil record of horses has made them a classic example of evolutionary processes. However, while the overall picture of equid evolution is well known, the details are surprisingly poorly understood, especially for the later Pliocene and Pleistocene, c. 3 million to 0.01 million years (Ma) ago, and nowhere more so than in the Americas. There is no consensus on the number of equid species or even the number of lineages that existed in these continents. Likewise, the origin of the endemic South American genus Hippidion is unresolved, as is the phylogenetic position of the “stilt-legged” horses of North America. Using ancient DNA sequences, we show that, in contrast to current models based on morphology and a recent genetic study, Hippidion was phylogenetically close to the caballine (true) horses, with origins considerably more recent than the currently accepted date of c. 10 Ma. Furthermore, we show that stilt-legged horses, commonly regarded as Old World migrants related to the hemionid asses of Asia, were in fact an endemic North American lineage. Finally, our data suggest that there were fewer horse species in late Pleistocene North America than have been named on morphological grounds. Both caballine and stilt-legged lineages may each have comprised a single, wide-ranging species.

Description: Habitat-forming species sustain biodiversity and ecosystem functioning in harsh environments through the amelioration of physical stress. Nonetheless, their role in shaping patterns of species distribution under future climate scenarios is generally overlooked. Focusing on coastal systems, we assess how habitat-forming species can influence the ability of stress-sensitive species to exhibit plastic responses, adapt to novel environmental conditions, or track suitable climates. Here, we argue that habitat-former populations could be managed as a nature-based solution against climate-driven loss of biodiversity. Drawing from different ecological and biological disciplines, we identify a series of actions to sustain the resilience of marine habitat-forming species to climate change, as well as their effectiveness and reliability in rescuing stress-sensitive species from increasingly adverse environmental conditions.

Description: Aquatic ecosystems worldwide continue to experience unprecedented warming and ecological change. Warming increases metabolic rates of animals, plants, and microbes, accelerating their use of energy and materials, their population growth, and interaction rates. At a much larger biological scale, warming accelerates ecosystem-level processes, elevating fluxes of carbon and oxygen between biota and the atmosphere. Although these general effects of temperature at finer and broader biological scales are widely observed, they can lead to contradictory predictions for how warming affects the structure and function of ecological communities at the intermediate scale of biological organization. We experimentally tested the hypothesis that the presence of predators and their associated species interactions modify the temperature dependence of net ecosystem oxygen production and respiration. We tracked a series of independent freshwater ecosystems (370 L) over 9 weeks, and we found that at higher temperatures, cascading effects of predators on zooplankton prey and algae were stronger than at lower temperatures. When grazing was weak or absent, standing phytoplankton biomass declined by 85%–95% (〈1-fold) over the temperature gradient (19–30 °C), and by 3-fold when grazers were present and lacked predators. These temperature-dependent species interactions and consequent community biomass shifts occurred without signs of species loss or community collapse, and only modestly affected the temperature dependence of net ecosystem oxygen fluxes. The exponential increases in net ecosystem oxygen production and consumption were relatively insensitive to differences in trophic interactions among ecosystems. Furthermore, monotonic declines in phytoplankton standing stock suggested no threshold effects of warming across systems. We conclude that local changes in community structure, including temperature-dependent trophic cascades, may be compatible with prevailing and predictable effects of temperature on ecosystem functions related to fundamental effects of temperature on metabolism.

Description: The present volume gives the observed physical and chemical data obtained by R. V. "Meteor" in the Indian Ocean during her cruise 1964/65. The tables are based on the computations made by the National Oceanographic Data Center (NODC) in Washington. In addition to the normally communicated data, the tables contain four chemical parameters: alkalinity, ammonia, fluoride, and calcium.

Description: In this paper the sections for temperature and salinity are presented, which were obtained during the cruise of R. V. "Meteor" in the Indian Ocean (1964/65). The hydrographic observations in the Arabian Sea, had the aim to provide information on the influence of the NE-monsoon on the distribution of salinity and temperature off the east coast of Africa and off the west coast of India. Special attention was given to the spreading of highly saline water from the Red Sea and the Persian Gulf. The track of the expedition was layed out according to these plans and is presented in figure 1. The data were collected by means of hydrographic casts with newly developed water bottles, and by means of "in-situ" measurements with the "bathysonde", an instrument for the continuous recording of electrical conductivity, temperature and pressure. This paper only deals with the data of the casts which are presented in a special publication together with the chemical data. The hydrographic conditions off the east coast of Africa are characterised by a rather complicated distribution of salinity within the first 1000 m of depth with several intermediate maxima and minima (hydrographic sections III-IX). This is due to the spreading of highly saline water mainly from the Red Sea, which can be traced southwards at least as far as 4° N (figure 9). Similar complicated conditions were found off the west coast of India (sections XI-XVI). Here the cause can be traced back to watermasses from the Persian Gulf. In depths below 2 000 m the TS-relation is virtually the same at both sides of the Arabian Sea.

Description: The present investigatioh concerns itself with two problems: First it is investigated with the aid of the hydrographic data available until medio 1965 from the Indian Ocean, whether due to the varying actions of the monsoons a large scale seasonal shift in the distribution of the isohalines occurs at the level of intermediate salinity maxima ( depth range about from 300 to 800 m). Furthermore it is investigated by means of two theoretical models whether advection or horizontal mixing dominates in the large scale distribution of the salinity in the Arabian Sea. In the treatment of the first problem, distribution charts for the water from the Read Sea and the Persian Gulf were made with the aid of the core layer method for both monsoon periods. The core layer of Red Sea water lies at about 600 to 800 m depth. The watermasses from the Persian Gulf sink from 200 to 500 m while moving from north to south. In both seasons the observable limit of extension lies at about 3° N. Seasonal variations occur apparently only in the northern part of the basin and at its margins. The observed distribution of salinity shows at all levels (300, 400, 500, and 600 m) an east-west pattern (fig. 7 to 10). In no case a tongue form appears in the isohalines. The observed distribution is satisfactorily interpreted by means of a model which considers only horizontal mixing and the natural boundary conditions (Dirichlets problem for the rectangle). A further model which includes advective terms does not corroborate the observations. The investigations lead to the conclusion that the existing stationary distribution of salinity in the central part of the Arabian Sea is maintained essentially by large scale mixing processes. Further theoretical considerations, which are based upon observations at the 800 m level, suggest that the distribution of salinity at the margins of the basin strongly influences the salinity of the inner part. A change in the marginal distribution on the other hand, may be caused by means of horizontal movements of relatively small width. In further investigations on the circulation of the Arabian Sea one has therefore to consider especially the processes at the margins of the basin.

Description: Although vertical velocities are very small, they are of great importance with regard to chemical and biological processes in the sea. A study of the circulation phenomena of down- and upward moving watet masses is not possible experimentally. Therefore, the vertical velocities were determined by means of a theoretical model using empirical data obtained by R. V. "Meteor" in the Arabian Sea, during the period of tbe NE-monsoon 1964/65. Based upon the observed data for the density the physical topography of the sea level was calculated by means of the dynamic method. The wind registrations during the hydrographic stations of R. V. "Meteor" show a very constant wind distribution of the NE-monsoon. The data of wind distribution, shapes of sea level and pycnocline were used in a simple two dimensional two layer model with two constant densities and two constant vertical eddy coefficients. The main results are presented in horizontal charts for four levels from O to 300 m for the African and for the Indian coast (plate 6 and 7). The charts show alternative strips of weak upward and downward movements parallel to the coast. The width of the strips varies from 30 to 80 km. There are three areas of intensified vertical velocities: south of the island of Socotra (profile III), south of the equator near the coast of Mombasa (profile VIII), and southerly from Karachi (profile XV). These results of stripwise distribution of upward and downward velocities are compared for one case with the distribution of particulate carbon, which shows a similar alternative distribution of minimum and maximum values (plate 8). Maximum velocities of 2 · 10-4 cm/sec occur in profile XV, in the layers between 100 and 200 m. On the other profiles velocities are less than 10-5 cm/sec. In all cases it was found that the vertical velocities reach a maximum well below the pycnocline, in order to decrease in either direction.

Description: During the expedition of R.V. "Meteor" in the Indian Ocean the following data were observed on a section from 58° E, 3° S to 58 ° E, 2° N during the end of january 1965: Temperature and salinity by hydrographic casts as well as by continuous registrations with the bathysonde. In addition, observations of several chemical parameters, and measurements of the meridional and zonal current distribution down to 250 m depth were obtained. The results indicate no evidence of an eastward directed equatorial undercurrent towards the end of january 1965: On the contrary, we find relatively strong westward directed currents. Chemical data corroborate this fact as there is no similarity with the distribution of oxygen or phosphate on transequatorial sections from the Pacific or the Atlantic Ocean. A weak eastward directed component of current at 3° S indicates the appearance of the equatorial counter-current. The bathysonde-registrations indicate the existence of at least two characteristic watermasses: Water from the Arabian Sea between 50 to 100 m depth and water from the Red Sea at 700 to 800 m depth.

Description: The Red Sea has a special place among the adjacent seas of the world. High evaporation, exclusion of its deep water from contact with the Indian Ocean proper and complete absence of continental drainage may result special conditions of the chemistry of the Red Sea. This paper aims to describe and to explain the peculiarity of the hydrochemical situation. The influence of the topography, of the inflow and outflow through the straights of Bab el Mandeb, of the evaporation, of the stability of the water layers, and of the circulation will be studied. An attempt is made to estimate the apparent oxygen ultilisation in order to obtain an indication of the biological activity. A further attempt is made toward the quantitative estimation of the circulation of the nutrients and also to obtain some information about transport, dissolution, and precipitation of calcium carbonate. The basis of these investigations are mainly observations of R. V. "Meteor" during the International Indian Ocean Expedition 1964/65.

Description: After almost exclusive use in oceanographic research, the R. V. "Meteor" conducted tests in fall 1967 in the Baltic Sea which were devoted to an important problem in ship building research. In order to check the transfer of model test results to prototype conditions, which has become somewhat uncertain in view of the increase in size and speed of modern vessels, a model family of this ship had been tested at scales of 1: 25, 1 : 19 and 1 : 13 .7 5, and full scale tests were to complete the series. The most important measurements included resistance, propeller thrust and propeller power demand. Furthermore, the nomial wake in the absence of the propeller and the effective wake in front of the working propeller, the velocity distribution in the boundary layer at one point of the hull at least and the behaviour of the ship during manoeuvering with and without propeller have been investigated. The most difficult task consisted of the determination of the resistance as a function of speed, because the ship could not be driven by propeller for these tests, but had to be moved, similar to a model on a towing carriage, by a known force exerted above the water surface. Following the historical example of the resistance tests on the ferry boat "Lucy Ashton", the "Meteor" was supplied with 3 jets, which, with a maximum thrust of about 10 Mp at 12 OOO PS, produced a forward speed of 12 kn (Fig. 1, i., 3). The jet thrust was measured by strain gauges on the diagonals in the supporting frame of each jet (Fig. 3). Measurements of thrust and torque of the propeller were also obtained from strain gauges on the propeller shaft (Fig. 7). Wake measurements were performed with pitot tubes and a total head tube fixed on a rake (Fig. 4) which could be turned by 180° on the stem tube. Boundary layer measurements were obtained by two Prandtl tubes which could be moved sideways at the hull (Fig. 6). Rudder forces were indicated by a three component balance on the rudder shaft. Ott current meters and Prandtl tubes, calibrated on the mile distance, gave the ship speed. All measurements were performed electronically with analog and digital registration. The results obtained so far are remarkably accurate. Plotting the resistance values in the system of the model family indicates, that the ITTC 1957 line, presently in use as an extrapolator for frictional resistance, has too small a slope (Fig. 11 ). The total efficiency of model and prototype is about equal (Fig. 14), and the thrust deduction fraction does not seem to depend on the scale either. For the law of the wall of the boundary layer, the values K = 0.41 and C = 5.0 from recent laboratory tests are supported (Fig. 15). The evaluation of all results will probably be finished by the end of 1968.

Description: Serial observations of temperature, salinity, oxygen, alkalinity and pH are presented. They were carried out during an anchor station of R. V. "Meteor" west of Cape Sao Vincente (Portugal) in the area of the maximum Mediterranean water outflow, which follows the continental slope off Portugal. Two observational results are pointed out: The Mediterranean water masses spread out into the Atlantic Ocean, consisting of two distinct layers at depths of 700 m (T = 12.0 °C, S = 36.15‰) and 1250 m (T = 11.3 °C, S = 36.40‰). The salinity proved to be the most significant indicatot of the observed stratification (see figs. 2, 3, 4 and 5). The values of dissolved oxygen content, alkalinity and pH in the very near bottom layer (1 m above the bottom at depths of 3250 m) are different from the values at depths of 15 m to 1000 m above the bottom (see figs. 11, 12 and table 1). As this phenomenon is not observed for the salinity, the changes may be interpreted in terms of chemical and biological processes at the sediment - water interface.

Description: The following tables show physical and chemical data observed by the "Meteor" in the Persian Gulf and the Strait of Hormus. This study was performed in accordance with the general programme of the International Indian Ocean Expedition (IIOE) during the period from March 25 th until April 16th, 1965. The water temperature was measured by reversing thermometers; in most cases two instruments were used simultaneously. The absolute mean temperature difference of this double measurement is 0.0153 °C. The salinity was determined both by salinometer and by titration. In this case the absolute mean difference amounts to 0.0174‰. The computations of the density, the specific volume anomaly, the dynamic depth anomaly, the sound velocity and the interpolation for standard depths were carried out by the National Oceanographic Data Center (NODC), Washington.

Description: Changes in the dissolved oxygen content, the alkalinity, and the pH in sea water near the ocean floor are interpreted in terms of chemical and biochemical processes at the sediment water interface. A simple model provides a plausible explanation of the observed phenomena. Special emphasis is given to the importance of borate corrections in the calculation of the solution effects of calcium carbonate.

Description: Continuous Bathysonde profiles of temperature versus pressure were used to follow the depths of isotherms at a deep sea anchor station northwest of the Great Meteor Seamount (30 ° N, 28 ° W) from 19th to 27th of April 1967. Assuming temperature to be a conservative parameter, vertical velocities can be computed from the vertical displacements of isotherms, according to equations (1) or (7), respectively. Several advective terms of higher order, however, seem to be large compared to lower order terms (see equ. (7) and table 1). In addition, advective velocities are only known approximately for the period of the measurements. Therefore the total vertical velocity for each depth could not be determined. However, it can be assumed that vertical velocities of semi-diurnal tidal period are large compared, to vertical motions of other frequencies (see fig. 2). The vertical velocity of the semi-diurnal tidal motion can therefore be computed from equ. (10) (table 2). A subsequent approximation of the observed distribution of the vertical velocity component by eigenfunctions reveals a reasonable description of the baroclinic semi-diurnal tide by internal gravity wave modes of the order 1-4 (see fig. 5).

Description: Based on measurements during the "Atlantic Seamount Cruises 1967" with the German R. V. Meteor, (see Cwss et al., 1969; HORN et al., 1971), the fluctuations of temperature in the upper 275 meters are investigated. The analysis of 67 time-series yields the following : 1. Within the period range from 124 hours to 10 minutes fundamental oscillations and their harmonics occur permanently with relatively high amplitudes. These oscillations could be attributed to the diurnal (K1) and semidiurnal (M2) surface- and internal tidal waves as well as to their harmonics. It ought to be mentioned that in the surveyed area the K1-tide and the inertial wave have the same periods and could not be separated by spectrum analysis. 2. Interactions between the K1- or M2-waves and their harmonics by single superposition are shown in the observed periods. These two facts possibly can be explained by the perturbative influence of the Great Meteor Seamount on long wave motions. 3. Special investigations of the short period range lead to significant oscillations with periods between 15 and 40 minutes, which correspond to the Brunt-Väisälä-frequency calculated from the mean density distribution. 4. The diurnal variation of tempernture at the sea surface has a mean amplitude of 0.3 °C and a penetration depth of about 55 m. The mean vertical eddy conductivity amounts to 260 g cm-1 sec-1.

Description: Data obtained during the "Atlantic Seamounts Cruises 1967" with the German R.V. "Meteor" in the area of the Great Meteor Seamount (30 ° N, 28 ° W) are presented graphically. Sections of temperature, salinity, oxygen, pH and alkalinity (figs. 2-5) generally show horizontal homogeneity, which is obviously disturbed around the top of the seamount. This is conformed in greater detail by the results of two bathy thermograph-sections (figs. 6, 7). The time dependence of variations in stratification and currents is presented in figs. 8-10 and 12-17. They clearly indicate the presence of tidal motions, which are amplified in the area above the plateauby a factor of 4. The marked differences in the vertical amplitude distribution suggest the occurrence of internal (tidal) waves. Figs. 18 and 19 graph the residual currents, which show significant deviations from a uniform directional behaviour, especially in the bottom layer on top of the seamount. Various aspects of the data will be treated by HoRN (1971), HUSSELS (1971) and MEINCKE (1971).

Description: The first expedition planned for 1970 was conducted in the ocean area between the Iberian and West African coasts (north of 15 ° N and 30 ° W, see map). The first three sections of the expedition were devoted mainly to biological questions. The fourth and last cruise-section was concentrated on geological and geophysical problems relating to the exploration of the Iberian shelf and shelf margin. Since the activation of R.V. "Meteor" in 1964, biological work has predominantly centred round two questions: a) comparative studies on nutrient dynamics in poor and rich areas and b) communities in the open ocean and their diurnal periodic migrations. It was the purpose of the Canaries Basin expedition to supplement the data collected during previous research cruises, particularly the Atlantic Seamount cruises ("Meteor" cruise 8 and 9) in 1967 and the West African expedition ("Meteor" cruise 13) in 1968. Research work in the various disciplines of marine biology was carried out simultaneously with the collecting of chemical and physical data indispensable for the understanding of productivity, transport and decomposition of organic matter as well as affording an opportunity to observe biogenic sedimentation. In planning the cruise, special emphasis was laid on ensuring as close a coordination as possible between the individual working programmes; it was decided that of the vast number of problems presently confronting marine science, particularly in the biological field, only a few should be selected and these approached from diverse sides. Each cruise section was directed at one focal point, around which other investigations were grouped. Cruise section I. Nutrient dynamics in an upwelling water body off the West African coast. Cruise section II. Communities and environmental conditions in the region of the Great Meteor Seamount. Cruise section III. Metabolism and communities on the Iberian deep-sea bed. Cruise section IV. Testing of geophysical gear. Moreover, investigations on two important questions that for a considerable length of time have occupied the attention of planktologists and geologists at various German institutes covered several cruise sections: a) The structure of communities in the oceanic deep scattering layers and at the sea surface; an insight into the feeding migrations of these organisms is essential for an understanding of the vertical transport of organic matter in the open sea. b) The origin of sediments in the deep sea and on the Iberian shelf in relation to organic productivity and climatic and oceanographic fluctuations. The Canaries Basin expedition 1970 inaugurated the "Cooperative Investigations of the Northeastern Central Atlantic" (CINECA), a programme coordinated by the International Council for the Exploration of the Sea (ICES) on the recommendation of the FAO and IOC.

Description: The Persian Gulf situated in the arid climate region of the northern hemisphere shows special conditions in its hydrochemistry. The high evaporation, the lack of large rivers, and the exclusion of deep water from the Indian Ocean governs the nutrient cycle. At 95 stations in the deeper part of the Persian Gulf (Iran side), in the Strait of Hormuz, and in the Gulf of Oman determinations of dissolved oxygen, dissolved inorganic phosphate, silicate, and pH were carried out. The data are compiled in the data report (BRETTSCHNEIDER, GRASSHOFF, KOSKE & v. TREPKA 1970). The ammonia, nitrite and nitrate data from 30 stations are added to this report. On 4 selected transverse profiles for phosphate, and dissolved oxygen and on 1 length profile for phosphate, silicate, oxygen, and pH the distribution of these components is shown and the in- and outflow is characterized. It is also pointed out that the nutrients on their way into the Persian Gulf are diminished and that temporary replenishment supply from a layer of about 100 m depth in the Indian Ocean follows. On one horizontal map the phosphate distribution in the surface and 30 m layer gives reference to biological activity. One diagram where nitrogen components are plotted against phosphate shows that nitrate is a limiting factor for productivity. 02/P04-P and P04-P/S‰ diagrams enable the different waterbodies and mixed layers to be characterized.

Description: In July, August and September 1969 a joint German-Icelandic-Norwegian-Expedition investigated time- and space-dependent oceanographic processes in the Norwegian Sea (fig. 1) and in the waters east of theIcelandic Shelf as weil as the geological and geophysical structure of the Norwegian continental slope, the Norwegian Basin and the Jan-Mayen-Ridge. The participating research vessels were "Hafthor" from Iceland, "Helland-Hansen" from Norway, "Anton Dohrn" and "Planet" from the Federal Republic of Germany (FRG) and as shooting vessel "Nordkapp" from Norway. "Meteor" (FRG) was eliminated from the measuring programme because of engine trouble shortly before begin. Due to the prolonged activity of "Planet" the originally planned investigations were almost entirely able to be carried out. The measuring programme and the preliminary results of the geological and geophysical working groups are dealt with separately (Closs et al. 1972). Systematic sounding from "Planet" in the main working area between 62° and 63° N, and 3° 25' and 4° 50' E forms the basis for a special contour map (see supplement). As a result of improved mooring technique in the course of the expedition's oceanographic measuring programme an almost one hundred percental retrieval of instruments was achieved and herewith 49 current and 55 continuous temperature recordings over 12 to 45 days in depths between 10 and 800 m were obtained. Hydrographie sections, nine anchor- and driftstations as well as one in five days six times successively passed through triangular course gave information over stratification and its periodic changes. The distribution of stations and the position of the moored self-contained instruments in the main working area is found in figure 2. Figure 3 gives insight into the registration period and depth of the instruments of the by "Planet" in cross formation moored systems I to VI. Parallel to the work clone off Norway observations were made as to variability of physical and chemical parameters in east Iceland waters.

Description: During the "Atlantic Expedition" in 1965 (IQSY) a comprehensive bathymetric survey and a few hydrographic stations were made by R.V. "Meteor" in the equatorial region of the Mid-Atlantic Ridge. The survey results are shown in a bathymetric chart covering the western parts of the Romanche- and Chain Fracture Zones. West fo the original Romanche Trench another deep trench with a medium depth of 6000 m was discovered. The maximum sounding obtained was 7028 m. Both trenches apparently belong to the same fracture zone, but are distinctly separated from each other. The western boundary of the trench against the Brasil Basin is formed by a sill rising to a depth of about 4400 m. The serial hydrographic observations give some indications of the flow of the cold Westatlantic deep watet in the fracture zone area and its influence on the hydrographic conditions in the East-Atlantic Basin. The upper limit of the nearly homogenious Westatlantic bottom water with an Antarctic component lies in about 4400 m. The water mass entering the system of trenches of the Romanehe Fracture Zone over the western sill originates from the lower part of the discontinuity layer lying above the bottom watet. Potential temperatures of 0.6 °C were the lowest observed by "Meteor" in the western trench. There seems to be a remarkable tongue of relatively high salinity and a minimum of oxygen in the deep watet of this trench. At present we can only speculate upon the origin of this highly saline deep water tongue underneath the eastward moving relatively thin layer of less saline Westatlantic deep watet. In the range of the sill separating both trenches a lee-wave is indicated by the distribution of salinity and oxygen, which implies a vertical transport of water masses. Caused by this transport it is assumed that relatively cold watet may be lifted temporarily to a depth, where it can pass the northbounding ridge, thus getting directly into the Sierra Leone Basin. In the original Romanche Trench the cold Westatlantic deep water seems to fill the whole trough, but its extension remains limited to the trench itself. The water masses found east of the sill separating the trench from the East-Atlantic Basin originate from the lower part of the discontinuity layer. With potential temperatures of about 1.3 °C they are much warmer than those observed in the Romanche Trench bottom water.

Description: At first a technique is presented to evaluate repeated hydrographic sections. In order to separate the periodic variations and the fluctuations which arise as a result of the horizontal motion of the profiling ship, the data at defined locations are averaged relative to time. The procedure of averaging can be applied successfully to sets of sections repeated at a constant rate under the assumption that the spatial field is approximately stationary during the time of observation and that the energy of the overlapping temporal processes is concentrated over a few spectral bands. In these cases, the mean spatial distribution can be expected as a result. The periodic part is extracted as the deviation of the actual sections from the averaged section. This procedure was applied to a set of observations made at 28 discrete stations along a triangular course at the continental shelf off the coast of Norway during the expedition "Norwegian Sea 1969". Temperature sections were repeated six times at an interval of 18 hours. The average section shows the expected downsloping of the isotherms perpendicular to the continental shelf corresponding to the Norwegian current. lt turns out that the fluctuations with respect to time during the period of observation are probably produced by semidiurnal internal tides. Wavelength and phase velocity are estimated to be A = 22 km and c = 0.5 ms-1 respectively. The waves progress towards the shelf at right angles. For depths of 250-500 m at the continental slope a considerable amplification of wave is noticed.

Description: The seaward extension and vertical structure of the Coastal Current have been studied, on the basis of a repeated hydrographic section across the Norwegian Shelf off Stad. Current measurements were obtained from five anchor stations. The current ellipses do not reveal a consistent picture of the tidal current system, indicating that the observed currents may be influenced by internal tidal waves.

Description: The N2O in air and sea water from the Iceland-Faroe ridge was analyzed during the research vessel "Meteor's" cruise 20b from May 30 to July 4, 1970. Depths of the water samples varied from surface to 1000 meters. An improved analytical method yielded an average value of 0.495 micrograms of atmospheric N2O per liter (STP) of air. A slight N2O supersaturation of the water samples with respect to air was demonstrated.

Description: A bottom water sampler ("Suctor") for application in the deep-sea, in shallow waters and in estuaries is described. It is operated by hanging it on a wire and placing it on the sea floor. After waiting for 5-20 min for allowing the stirred sediment to be removed, an electrical pump installed in the sampler is operated from board of the ship. The bottom water sampler then samples simultaneously a volume of 10 litres from each 8 depths between O and 200 cm above the bottom. The samples are sucked into plastic bags through silicon rubber tubes; both the bags and the tubes can be kept extremely clean. The samples can be stored on board in the bags or can be connected to a filtering apparatus. During operation the bottom water sampler is connected with the ship by a wire, a conductor cable and the signals of the pinger device. Hence, its operation can be controlled on board at any time. During "Meteor" expedition 23 (summer of 1971) the sampler was used successfully between Madeira and the Straits of Gibraltar. Currents of 0-2 cm/sec were observed during operation by use of a Richardson current meter operatecl 44 cm above the bottom. The compass data of the current meter prove that the bottom water sampler maintained rigid contact with the sea floor. Analysis of particular organic nitrogen did not reveal significant gradients within the first two metres above the bottom.

Description: Hydrographie data (salinity, temperature, oxygen, silicate, and phosphate) obtained on 5 stations ("Meteor" cruise 23, leg C, 8 to 26 June 1971) on a section from Lisbon, Portugal, to 44° N, 43° W (Newfoundland Basin) by both water sampling and in situ observation by the "Bathysonde" (STD), are summarized. A strong core of Mediterranean water was found at the eastern boundary of the section (38.5° N, 11.5° W). At this station, the core is accompanied by low nutrient concentrations and brings about an extended oxygen minimum (ca. 500 to 1400 m depth). The core quickly weakens towards the west and is, at the Mid-Atlantic Ridge, only apparent in the Bathysonde data. Two salinity maxima are observed within the core of Mediterranean water, the center of which speads along the isopycnal σt = 27.7. Dissolved oxygen shows a rapid concentration increase with depth below the Mediterranean water core; concentration variations with depth below the range of this increase are only small. The mean deep-water oxygen concentration increases from 5.5 ml/kg (below 2500 m) to 6.20 ml/kg (below 1500 m) in an east-west direction on the section. The upper boundary of the deep-water oxygen concentration range thereby rises from 2000 to 1300 m; this boundary marks the upper boundary of the Arctic Intermediate water. Core depths of Arctic Intermediate and of Iceland-Scotland overflow water, are derived from the potential-temperature/salinity diagrams obtained in the western basin, and are extended to the other stations by assuming lateral spreading to occur along isopycnal surfaces. The core depths for the Intermediate water obtained in this manner, are supported also by the potential-temperature to silicate relations. The bottom water of the westernmost station of the section, at 44° N, 43° W, is of Denmark Strait origin, and it produces a distinct reversal in the vertical trends of salinity, silicate, phosphate, and oxygen, at 4300 m depth. The concentration of the nuclear-weapon produced nuclide tritium increases within the Denmark Strait water core towards the bottom. Further tritium concentration peaks appear in the intermediate and deep water at this station. At the next Station east on the section at 43° N 34 ° W, tritium concentrations are essetially zero below 2000 m depth, and are distinctly smaller than on the westernmost station, between 600 m and 2000 m depth. This "Meteor" section was track F of the Atlantic network of the international Geochemical Ocean Sections Program (GEOSECS).

Description: Some current meter data obtained from a mooring at 2450 m water depth near the continental slope off Portugal are presented. The mean currents at five levels with observations are northward. Mean speeds in the core of the Mediterranean Water exceed speeds at shallower levels by 2 to 3 cm/sec, indicating advection connected to this specific water mass. The current variability is dominated by semi-diurnal tidal components. Normal mode analysis reveals a predominant mode of order 2, representing 48% of the total kinetic tidal energy. Results for the barotropic tidal component are in good agreement with earlier predictions for this area. The motion at higher frequencies ω in the internal gravity wave band can be well described by a ω-2 power law for the energy density spectrum. This result is consistent with earlier observations in other parts of the ocean.

Description: Continuous temperature and salinity profiles from the NE-Atlantic frequently show a double-maxima straucture within the depth range of the Mediterranean outflow. Two explanations for this special thermohaline stratification con be found in literature: a) The density of the outflow is varied by different outflow channels with unequal mixing properties. b) In the Strait of Gibraltar two different outflowing water types are produced by tidal currents. in both cases the different water masses spread in different density levels in the Atlantic. Data presented here indicate that the bimodal straucture must be caused primarily by tidal currents at the source. Two-layered outflowing Mediterranean water was observed even before a splitting of the under-current in the Gulf of Cádiz takes place. The variability of the double-maxima can be explained by varying outflow rates in the source region rather than by a steady influence of the bottom topography.

Description: Data on the N2O contents of marine air and sea water from the Northeast Atlantic Ocean are presented. The N2O content of marine air is rather constant. The data are in accordance with earlier measurements. The sea water down to depths greater than 1,000 meters is considerably supersaturated with N2O with respect to air. Supersaturation values obtained from surface water allow the conclusion that part of the North Atlantic acts as a net source of atmospheric N2O.

Description: The expedition "Auftrieb '72" was conducted in the NW African Upwelling Region off the Banc d' Arguin and included two geological profiles off Cap Blanc and off Villa Cisneros. R.V. "Meteor" and R.V. "Planet", the research plane "Canberra" and the tourist vessel M.S. "Regina Maris" participated in the expedition. Several components added up to a coordinated programme of different disciplines: Current meter moorings, large-scale oceanography and intensive studies of frontal zones were the task of R.V. "Planet". Medium-scale oceanography, chemistry and various disciplines of marine biology were performed with R.V. "Meteor", while the airplane and M.S. "Regina Maris" supplied background oceanographic information for the whole programme. The work done with R.V. "Meteor" is reported here. lt has been organised in three sections: Cruise section I. Nutrient dynamics in upwelling water bodies, in continuation of the work done during the "Roßbreiten-Expedition 1970". Cruise section II. Circulation in an upwelling system, including direct measurements of the vertical velocity; mixing processes in an upwelling system. Cruise section III. Sediment and benthos in areas of strong and weak upwelling. The approach to the study of these processes varied according to the problem. During cruise section I a number of drift experiments similar to the experiment conducted during the "Roßbreiten-Expedition 1970" was performed, consisting of a regular station programme at a freely drifting buoy which served for marking a patch of upwelling water. Cruise section II consisted of repeated sections in the vicinity of the vertical current meters and the current meter moorings. Cruise section III concentrated on two profiles perpendicular to the coast off Cap Blanc and Villa Cisneros.

Description: Temperature data are presented which were obtained by means of a towed thermistor cable during the expedition "Auftrieb '72" in the immediate vicinity of the continental slope within the NW African upwelling region. While most of the data have been sampled on the offshore side of the upwelling front, the front is crossed on a few occasions, and some data cover the area of the upwelling coastal jet. They reveal a very deep homogeneous surface ]ayer within the coastal jet, indicative for increased turbulent mixing. These conclusions from the temperature sections are confirmed by the temperature and salinity data from CTD casts made in the same area at the same time. In spite of the complicated hydrography of the area and the large number of water masses involved, the existence of a zone of increased turbulent mixing within the jet is indicated in the data.

Description: At seven sites west of Gibraltar current and temperature variations of the Mediterranean outflow were observed during one month in spring 1971. This paper presents the obtained records of 29 current meters and 5 thermistor cables in the form of time series, amplitude spectra, and progressive vector diagrams as a basis for further evaluation. Characteristic featurcs of the currents like mean spceds, mean directions and the periodicity of the variation can be seen directly from the given plots.

Description: During "Meteor" cruise 23 in spring 1971 intensive investigations of the Mediterranean outflow in the Gulf of Cádiz were carried out. In order to give a budget of the inflow and outflow numerous CTD-stations were taken. The observations also included six moored current meter arrays deployed in the known outflow channels. The considerations given here are based mainly on three hydrographic sections, current meter records averaged over one month, and geological observations from the bed forms beneath the Mediterranean undercurrent. The results show that the outflow essentially is determined by the bathymetry of the area. At least four separate outflow channels could be confirmed. The volumentric transport rates of three of them were calculated. These channels are the northerly near shelf branch (0.40 · 106 m3 sec-1), the main branch (1.39 · 106 m3 sec-1 in southwesterly direction, and an intermediate branch (0.24 · 106 m3 sec-l) found between both. In a static box model the progressive mixing of 0.95 · 106 m3 sec-1 pure Mediterranean Water with 1.97 · 106 m3 sec-1 North Atlantic Central Water is demonstrated.

Description: Oceanographic measurements by groups from the Federal Republic of Germany contributed mainly to the C-Scale Experiment (centered at 9° N, 23° W) and the Equatoria1 Experiment. In this paper the data are presented that were obtained from the moorings F 1 and F 2 in the C-area. After a short discussion of instrument problems, data processing and statistical analysis, the data are presented graphically as time series, progressive vector diagrams, frequency distributions and spectra of horizontal kinetic energy and of temperature variance.

Description: The results of measurements on currents and stratification obtained by FRV "Anton Dohrn" during the GATE-Equatorial Experiment are presented in graphical form. Remarks on data processing arid errors involved are made accordingly.

Description: We report, numerically and in graphical form, measured tritium concentrations from five hydrographic stations in the North Atlantic. Fairly homogeneous concentrations are observed in a surface layer typically 400 m deep. In the thermocline, concentrations decrease steadily down to the a σθ = 27.3 density horizon, and are more variable further down. The tritium in the lower part of the thermocline originates from the Subarctic Intermediate Water and the Mediterranean Water. There is a relative tritium maximum associated with the Mediterranean Water on the easternmost station of the section. In the deep water (σθ 〉 27.8), concentrations east of the Midatlantic Ridge are close to the limit of detection down to 2500 m, and undetectable further down, while west of the ridge tritium is found throughout the water column. The deep water tritium is associated with the deep-water advective cores of Arctic origin. The present tritium data can serve as northern boundary values in attempts to use tritium in studies of the North Atlantic main thermocline dynamics. The present data together with data from the literature point to a general division of the North Atlantic main thermocline into two layers separated by an isopycnal surface near σθ = 27.3.

Description: The distribution of 210Pb and 210Po in dissolved ( 〈 0.4-micron) and particulate (〉 0.4-micron) phases has been measured at ten stations occupied during cruise 32 of F. S. "Meteor" in the tropical and eastern North Atlantic. Both radionuclides occur principally in the dissolved phase. Unsupported 210Pb activities, maintained by flux from the atmosphere, are present in the surface mixed layer and penetrate into the thermocline to depths of about 500 m. Dissolved 210Po is ordinarily present in the mixed layer at less than equilibrium concentrations, suggesting rapid biological removal of this nuclide. Particulate matter is enriched in 210Po, with 210Po/210Pb activity ratios greater than 1.0, similar to those reported for phytoplankton. At depths of 100-300m, 210Po maxima occur, and unsupported 210Po is frequently present, an observation that suggests rapid re-cycling within the thermocline. Comparison of the 210Pb distributions with those reported for 226Ra at nearby GEOSECS stations confirms the widespread existence of a 210Pb/226Ra disequilibrium in the deep sea. Close to the bottom, profiles of 210Pb and 226Ra usually diverge, and 210Pb concentrations frequently decrease with depth, suggesting a sink for 210Pb near the seafloor. Particulate 210Pb concentrations ordinarily show little systematic variation with depth. At depths greater than 1,000 m, dissolved 210Po activities are, on the average, less than those of 210Pb by 12 % . A corresponding 210Po enrichment in the particulate phase is found.

Description: Pelagic tar has been collected daily on a transsect from off Prtugal to south of the Canary Islands in January/February 1975. A new neuston sampler was used which may be towed at speeds between 7 and 10 knots (DERENBACH & EHRHARDT 1975). A total of 22 samples was taken. Dimensions of tar balls ranged from potatoe-size to small specks approximately 1 mm in diameter. Concentrations were found to vary between 20.5 and 0.007 mg/m2, except for one instance of an extremely high tar concentration of 2270 mg/m2. 49 GC analyses were made. 61% showed bimodal peak distributions characteristic of crude oil sludges. The composition of tar balls was independent of their size suggesting diffusion controlled degradation.

Description: During the international "Overflow-Expedition" 1973 on R.V. "Meteor" oxygen concentrations in surface layers were measured in order to determine the oxygen gradients within the First two meters and to add some informations to the mechanisms of oxygen exchange at the air-sea interface. These investigations may be interesting also with regard to long-term-observations of the oxygen distribution in the Atlantic, especially the problem of the A.O.U. (apparent oxygen utilization) determination. To measure oxygen gradients a special sampler was built which is able to take water samples each 20 cm of the First 2 meters. These data were supplemented by further samples down to 150 m, taken by conventional water samplers, from which samples were also taken to measure N2/02-relations. By comparing these relations with theoretical relations in air-saturated water the influence of biological production and consumption on the oxygen contents in water could be estimated. A simple glass apparatus was built to extract gas from the water samples, and hereafter the N2/02-relations were determined by mass spectrometry. Most distributions of the oxygen anomaly show a negative oxygen balance which varies largely, probably due to strong mixing processes in the Iceland-Färö ridge area. The distribution of surface oxygen saturation values are of two different types. The values of the stations 260, 262 and 270 stem from mixed water and show homogeneous supersaturations, as can be found instantly when whitecaps appear. The values of 9 other stations are from water, sampled during calm periods which has been mixed and supersaturated before. They show a decreasing oxygen saturation towards the sea surface and often undersaturation in the upper decimeters up to 98% and even 91%. So at the air-sea interface even less initial oxygen saturation than 100% can be found after supersaturation during heavy weather periods.

Description: Records of currents and temperature on the upper edge of the continental slope off Sierra Leone show a significant energy peak between 0.3 and 2 cph in the bottom near layer. The fluctuations of temperature and velocity are interpreted as internal waves over a critical bottom slope. Since they seem to receive their energy mainly from the barotropic tide, the phenomenon is of interest in the dissipation cascade of tidal waves. The high frequency current amplitudes are occasionally strong enough to affect sediment deposition and related benthic processes. Inspection of current meter records from other regions of the NW-African continental slope reveal the similar effect of intensified bottom current fluctuations.

Description: A new technique for the harmonic analysis of current observations is described. lt consists in applying a linear band pass filter which separates the various species and removes the contribution of non-tidal effects at intertidal frequencies. The tidal constituents are then evaluated through the method of least squares. In spite of the narrowness of the fitter, only three days of data are lost through the filtering procedure and the only requirement on the data is that the time interval between samples be an integer fraction of one day. This technique is illustrated through the analysis of a few French current observations from the English Channel within the framework of INOUT. The characteristics of the main tidal constituents are given.

Description: 14C concentrations, as weil as 13C, hydrographic and nutrient data are reported for 5 hydrographic stations that form a transatlantic section near 40° N ("Meteor" cruise no. 23, 1971). Precision (for 14C ± 0.3% or better) and comparability with literature data are specified. A planned intercomparison with the US GEOSECS program within the Newfoundland Basin deep water failed because of variability of water characteristics. The observed 14C values decrease from about Δ 14C = + 80‰ at the surface to -70‰ at 2000 m depth. Deeper down, the values west of the Midatlantic Ridge remain similar, whereas those east of the ridge decrease further, to about -110‰. It is shown that bomb-14C is prominent down to about 1500 m depth. Beyond this depth the bomb 14C component is small and is negligible in the eastern basin below 2800 m. On the basis of the 14C-tritium correlation, the distribution of natural 14C below about 1500 m depth is derived from the observations. In the deep and bottom water east of the ridge the 14C-salinity relationship seemingly is non-linear. Contrary to expectation, the 14C concentration in the bottom water is not lower than found on an US GEOSECS station near 10° N. Apparently, lateral concentration differences in the Northeast Atlantic bottom water as well as nonlinearity of the 14C-salinity relationship at 40°N do not exceed 10‰ in Δ 14C.

Description: The grazing of different copepodite stages of Calanus finmarchicus on natural phytoplankton populations was measured at different times of day and night during the Fladen Ground Experiment (FLEX), from the end of May to the beginning of June 1976, at the central position of the "FLEX box" (58° 55' 00" N, 0° 32' 05" E), on board of the R.V. "Meteor". A big difference between nocturnal and diurnal food intake was found, particularly for the stages V & IV, which at night ingest 4 to 10 times more than during daytime. The maximal daily food intake (24 hours), taking into account the different feeding rates at the different times of the day and expressed as percent of own carbon weight, was found to be 31 %, 83 %, 115 % and 148 % for the copepodite stages V, IV, III, II and I together, respectively, with an initial feeding threshold at about 50-60 µg C · l-1. The total grazing for the upper 40 m depth layer was calculated for each sampling time; a very pronounced grazing rhythm was found, due to the higher ingestion rates at night combined with the vertical migrations. Maximal night ingestions were 100-200 mg C/m2/hour at the end of May to 300-400 mg C/m2/hour at the beginning of June, compared with 1-20 mg C/m2/hour at midday. Making a balance of the positive influence of particulate primary production and the negative influence of grazing on the stock of particulate carbon, we could show that the main cause of the decline of the phytoplankton bloom in this period was Calanus grazing. Other zooplankton activities, namely respiration, production and faecal pellets excretion as measured by four other authors are in balance with our results of ingestion.