ALBERT

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: Errors of wind speed measurements on buoys are mainly due to motions of the floating body. Additionally, the mast and/or the spars which carry the sensors, and special properties of the sensor itself, affect the accuracy of wind speed records. The error of these effects on: a) profile measurements; b) the determination of the vertical distribution of wind speed above water waves; c) spectral analysis and d) the eddy correlation n' w', is estimated by means of theoretical models, wind-tunnel results and observations from the Baltic Sea and the Atlantic Ocean.

Description: Measurements of atmospheric radioactivity attached to aerosols are described. Fallout was collected in a vessel of large area. Emphasis was on separation of "wet" and "dry" samples. For strontium 90a ratio of "wet" to "dry" fallout of 5:1 has been found independent of latitude. The total fallout was smaller than comparable values from continents because of very small amounts of rainfall in the equatorial zone. In order to achieve consistency in the global balance a better knowledge not only of radioactivity but also of precipitation over the ocean is required. Fallout of Ra-D clearly shows the ITC as a barrier for the latitudinal movement of near sea-surface air masses. The concentration of short-lived emanation daughters shows large variations according to varying geographic conditions. A variation with time could not be explained. The specific activity of long-lived radioactive substances shows the expected effect of the ITC as well as a seasonal diminuation of average concentration, similar to that measured at Heidelberg.

Description: During a four weeks anchoring station of R. V. ,,Meteor" on the equator at 30° W longitude, vertical profiles of wind, temperature, and humidity were measured by means of a meteorological buoy carrying a mast of 10 m height. After eliminating periods of instrumental failure, 18 days are available for the investigation of the diurnal variations of the meteorological parameters and 9 days for the investigation of the vertical heat fluxes. The diurnal variations of the above mentioned quantities are caused essentially by two periodic processes: the 24-hourly changing solar energy supply and the 12-hourly oscillation of air pressure, which both originate in the daily rotation of the earth. While the temperature of the water and of the near water layers of the air show a 24 hours period in their diurnal course, the wind speed, as a consequence of the pressure wave, has a 12 hours period, which is also observable in evaporation and, consequently, in the water vapor content of the surface layer. Concerning the temperature, a weak dependence of the daily amplitude on height was determined. Further investigation of the profiles yields relations between the vertical gradients of wind, temperature, and water vapor and the wind speed, the difference between sea and air of temperature and water vapor, respectively, thus giving a contribution to the problem of parameterizing the vertical fluxes. Mean profile coefficients for the encountered stabilities, which were slightly unstable, are presented, and correction terms are given due to the fact that the conditions at the very surface are not sufficiently represented by measuring in a water depth of 20 cm and assuming water vapor saturation. This is especially true for the water vapor content, where the relation between the gradient and the air-sea difference suggests a reduction of relative humidity to appr. 96% at the very surface, if the gradients are high. This effect may result in an overestimation of the water vapor flux, if a "bulk"-formula is used. Finally sensible and latent heat fluxes are computed by means of a gradient-formula. The influence of stability on the transfer process is taken into account. As the air-sea temperature differences are small, sensible heat plays no important role in that region, but latent heat shows several interesting features. Within the measuring period of 18 days, a regular variation by a factor of ten is observed. Unperiodic short term variations are superposed by periodic diurnal variations. The mean diurnal course shows a 12-hours period caused by the vertical wind speed gradient superposed by a 24-hours period due to the changing stabilities. Mean values within the measuring period are 276 ly/day for latent heat and 9.4ly/day for sensible heat.

Description: For the determination of the air temperature and its diurnal variation above the 500 mb-level at the equator station, at first the radiation error of the bimetal was investigated by means of a temperature comparison between the day- and night-ascents. The correction required can be obtained from an assembly of curves, that is represented from O to 90 degrees sunheight within 10 degrees distances for the pressure range from 300 to 3 mb. The error included amounts to about 10% of the correction value on account of the scattering of the temperature measurement. The mean diurnal variation of the air temperature is represented at the main pressure levels from 500 to 10 mb, but it is only recongnizable up to the 40 mb-level (about 22 km altitude). It amounts to 0.5 °C on the average. For higher altitudes the accuracy of the pressure- and temperature-measurements is no more satisfactory for this purpose.

Description: The nucleonic component of the cosmic rays has been measured by the German research vessel "Meteor" during the Atlantic Expedition IQSY 1965. The pressure corrected intensities fit well the rigidity calculations of KONDO & KODAMO. In this way we confirm the earth's magnetic field model used by these authors. Two positions of the cosmic ray equator have been determined at 29,7° W (6,5 ± 1) ° N and at 19° W (7 ± 1) ° N. These positions agree with the calculated values of KONDO & KODAMO. The total latitude effect of the nucleonic component amounts to 1.74 and 1.76. The measurements were carried out at solar minima activity. Using the values of latitude measurements at maxima solar activity the degree of modulation of the primary cosmic rays was determined in the rigidity range 2 - 13 GV. For rigidity values above 6 GV the modulation remains constant to 20%.

Description: Within the framework of the Indian Ocean Expedition of the German research vessel "Meteor" a total of 17 stations in the northern part of the Arabian Sea were measured with seismic refraction methods by the Geological Survey of the Federal Republic of Germany. In the Gulf of Oman and in the waters southeast of the Murray ridge a sequence with velocities of 2.9 to 3.7 km/s was proved below a sedimentary upper layer with a velocity increasing with depth. This sequence superposes a rock complex with 4.0 to 4.7 km/s. In all cases the underlying bed is constituted by rock material with a velocity of 6 km/s and more. Owing to the similar structure north and south of the Murray ridge it may be assumed that originally the part investigated in the Arabian Sea formed a unity, which was subdivided only recently when the Murray ridge developed. According to the results of the seismic refraction measurements this region, which presumably was a homogeneous one in the beginning, may with respect to its crustal structure be looked upon as both a seaward continuation of the Indus/Baluchistan basin and a transitional zone between the oceanic and the continental crust. An objection to the :first interpretation might be that there is no rock complex with 5 to 6 km/s, which seems to be typical of the structure of a continental crust. If the refraction horizon observed with velocities of more than 6 km/s (6.0-6.9 km/s) is correlated with the "oceanic layer" (layer 3), the considerable sedimentary thicknesses of more than 5 km and the depth position of the "oceanic layer" -exceeding those of other oceans by several thousand metres - suggest a transitional type of crust lying between the oceanic and the continental crust. Within the region of the present continental slope between Karachi and the peninsula of Kathiawar, sedimentary thicknesses (vp = 1.43 km/s to 3,7 km/s) of more than 5 km have also been observed. This sedimentary region designated as Kori marginal trough lies, towards the sea, in front of a high (Kori high). Within the Kori high, which in the present shelf region may be observed off Karachi towards the Southeast, the rock complex with a velocity of 6.2 to 6.5 km/s is upwarped. In the West, the Kori high is bordered by a remarkable system of faults. Within the Shelf region of Combay the rock complex with 6.5 km/s is upwarped. A direct connection between this high and the Kori high ma y be assumed; yet horizontal displacements possibly exist along the faults of the Cambay Depression, which extend towards the sea. Furthermore, a direct connection between the Kori/Cambay high and the Laccadiven zone seems possible according to the present state of investigations.

Description: Within the framework of the Atlantic Expedition in 1967 with F.S. "Meteor" about 900 sea miles were measured in the region of the Great Meteor Seamount (30° 00'N, 28° 30'W) by seismic reflection methods with a pneumatic sound source. According to the seismic investigations the Great Meteor Seamount mainly consists of volcanic compact rocks (vp = 5.8 km/s) superposed by a cap of seismically different sediment (vp = 2.7 - 3.7km/s). The results of the measurements are discussed by means of a number of seismic profiles and presented in the form of isochrone maps. Moreover the attempt is made to derive in rough outlines, the geological development of the Great Meteor Seamount from the seismic reflection data.

Description: Coccolithophorids agglutinated on the tintinnid-genera Codonellopsis, Codonella and Dictyocysta, and their ratio to agglutinated anorganic material are described on basis of plankton-tows from 12 stations in the Persian Gulf and the northern Arabic Sea. The results are compared with the distribution of two nannoplankton-species Cyclococcolithus leptoporus (MURRAY & BLACKMAN) and Braarudosphaera bigelowi (GRAN & BRAARUD) in recent sediments of the Persian Gulf and the northern Arabic Sea.

Description: The results of an investigation of tintinnids from the western Arabian Sea are described. A total of 134 closing-net samples was obtained from 22 stations of the German "Meteor" expedition 1964/1965. Distribution charts of the dominant species of tintinnids from the study area are presented as well as a list of the world-wide distribution of these species as derived from the literature. Tintinnids were most abundant in the surface waters. The layer from O-25 m yielded a maximum of 94.3% and a minimum of 61.3% of the tintinnids present from O-175 m; the mean was 80%, There was no significant difference in the vertical distribution between day and night stations nor wasb there any indication of the influence of the thermocline upon vertical distribution of tintinnids. TS-diagrams show different water types in the western Arabian Sea. Temperatur-salinity-tintinniddiagrams indicate regional patterns in the distribution of various species of tintinnids. Some tintinnids can be used as indicator species: Climacorylis scalaria, Parundella lohmanni and Amphorella amphora were typical for the Somali Current whereas Rhabdonella apophysata and Brandtiella palliata indicated the presence of Bast African Coastal Current water. The concentration of tintinnids in the upper 25 m ranged between 4,800 and 39,300 individuals/m3 (mean 19,000/m3). Plasma volume of tintinnids was calculated to permit comparison of different links in the food chain. There was a mean of 51 mm3/m2 in the upper layer, equivalent to a concentration of 2 mm3/m3. Carbon values were computed from the plasma volume of tintinnids, phytoplankton and larger Zooplankton. The ratio of phytoplankton plus microzooplankton carbon to large zooplankton carbon was 1 : 0.8 in the Somali Current, 1 : 0.4 in the Bast African Coastal Current and 1 : 1.2 in the mixing zone of these current systems. Tintinnids are one of the first links in the food chain. It is very likely that a part of the organic detritus and of the nanoplankton is transfered to large herbivores or omnivores via tintinnids and other protozoans. This mechanism might be especially effective during seasons when large phytoplankters are not available in the ocean.

Description: During the Atlantic Expedition "Meteor" 1965 the standard visibility was measured aboard with an AEG/FFM-Scattered Light Recorder. The working principle, technique and accuracy of this instrument is described. Furthermore some empirical results are discussed, e. g. the errors due to the disturbing influences of the ship and those caused by contamination of the lenses, The measured values are compared with estimated values of visibility by eyeobservation. For certain periods with uniform atmosphericconditions, hourly mean values of visibility have been correlated with air temperature, humidity and wind. The visibility shows a rather weak daily period for pure oceanic aerosol, whereas about 100 miles off the African coast the period appeared more pronounced. Interesting differences have been found in the relative changes of visibility for different origins of the aerosol. 'fhis results into a dependence of visibility on the wavelength of scattered radiation.

Description: During the 1965 Atlantic Expedition of the "Meteor" concentrations of various atmospheric trace gases were measured. The following gases were considered: carbon dioxide (C02), sulfur dioxide (S02), nitrogen dioxide (N02), and nitric oxide (NO). The air whereof these components were measured was sucked in from a height of 14 m above the surface of the sea. The results allow conclusions upon the long term global increase of the atmospheric C02 content, the meridional distribution of the C02 on the Atlantic Ocean, and the dependance of its concentration upon the time of the day and the thermal structure of the atmosphere. Attempts at determining concentrations of sulfur dioxide and nitric oxide of non-continental origin failed at large. Concentrations of N02, however, could succesfully be measured.

Description: A radiosonde is described for measuring the upward and downward fluxes of visible light in the atmosphere. Photoresistors are used as sensors, the optical center of the spectral range beeing at 0.55 µ. The results of these flux-measurements obtained during the Atlantic Expedition 1965 with the research vessel "Meteor" are presented. The datas have been divided into three groups according to the amount of cloudiness. In group a) ( small cloudiness) the extinction coefficient of the prevailing linear radiation is derived as a function of the height. Characteristics of airmasses of maritime or continental origin are shown. In group b) (cloud covered sky) microphysical quantities are determined from the radiative lapse rate in the clouds. The average radius of droplets is found to lie between 5.5 µ und 14.4 µ. The albedo of cloud surfaces varies between 25 % and 54 %, the transmission values are between 58 % and 73 %. One ascent through a Cirrus cloud of considerable vertical thickness is treated seperately. The observed distribution of extinction is compared with theoretical values in water clouds leading to the same order of magnitude. The relation between the albedo of the surface of the sea and the amount of cloudiness is discussed.

Description: During the Atlantic expedition potential gradient, small ion density and space charge density have been recorded. Laborious efforts have been taken for receiving an exact estimation of the reduction factor for the field measurements. The mean value of the potential gradient on the free Atlantic Ocean was 105 V/m. The mean daily course is in very good agreement with the results of the Carnegie Institution. Even records taken on individual days near the equator show this course. For the first time it has been attempted to correlate the potential gradient at sea and the voltage between ionosphere and earth measured over land. A narrow relation has been found in 10 cases of balloon ascents with radiosondes. A further remarkable result is, that the short periodical fluctuations of the air electric field at sea with periods of 2 to 20 minutes have amplitudes of the magnitude of the mean field strength and exist all over the oceans. Recordings of the space charge density show, that positively charged air parcels drift in the first hectometer of the air near the sea surface and produce the fluctuation of the potential gradient. A period analysis did not indicate a recognizable relation to the wind velocity up to now, although an effect of air turbulence must be involved. The concentration of small ions also has been measured occasionally. With this and mean values of the potential gradient the air earth curent density has been computed. With η+ = 310 cm-3, η_ = 220 cm-3 the air conductivity would be Λ = 1, 14 · 10-14 Ohm-1 m-1. These values are smaller than values of other authors by a factor of 2 or 3. Therefore the computed air earth current density is also smaller. The discrepancy could not be explained yet.

Description: The study of textural, structural, chemical, and physical properties of fine-grained recent marine sediments leads to the conclusion that only a few compositional factors are responsible for significant changes in mass physical characteristics in the upper meters below sea bottom. Fossil-induced porosity (text fig. 6) increases water content and liquid limit. It also seems to have partially influenced the plastic limit and plasticity index of calcareous sandy silts from the Red Sea and the western Gulf of Aden so that they become similar to the montmorillonite rich prodelta clays from the Nile Delta. Diagrams based on liquid limit and plasticity loose their original meaning in these cases (text fig. 7 a). Activity of sediments rich in microorganisms can be higher than that of montmorillonitic clay (text fig. 7b). The shear strength-depth relationship of normally consolidated sediments (text fig. 8 a) is surprisingly little influenced by changes in sand or clay content and clay mineralogy. Only high lime content, submarine erosion and beginning cementation increase the strength considerably (part of curves in text fig. 8 b ). Erosional disconformities near the present surface can be deduced from the strength-depth curve when as little as 1 or 2 m sediment have been removed (text fig. 9). Flat or irregular strength-depth curves (text fig. 8 b, curves B and GO) indicate beginning cementation and probably discontinuous sedimentation, provided the composition of the material remains in some degree constant. In our samples diagenetic pyrite, but no recristallisation of carbonates could be detected under the microscope. Underconsolidation and excess pore-water pressure, factors which tend to foster submarine slides, mud lumps, and diapiric folding, seem to be restricted to areas with mainly rapidly deposited, homogeneous or layered sediments. But where an abundance of burrowing organisms increases the vertical permeability of the sediment, normal consolidation and stable deposits are to be expected, at least in the upper meters below the present surface. According to 14C-determinations on calcareous microorganisms the rate of deposition of the investigated sediments seems to range from 26 to 167 cm per 1000 years.

Description: Two water samples and two sediment samples taken in 1965 by the R. V. "Meteor" in the area of the hot salt brine of the Atlantis II-Deep were chemically investigated, and in addition the sediment samples were subjected to X-ray and optical analysis. The investigation of the sulfur-isotope-ratios showed the same values for all water samples. This information combined with the Ca-sulfate solubility data leads us to conclude that, for the most part, the sulfate content of the salt brine resulted from mixing along the boundary with the normal seawater. In this boundary area gypsum or anhydrite is formed which sinks down to the deeper layers of the salt brine where it is redisolved when the water becomes undersaturated. In the laboratory, formation of CaSO4 precipitate resulted from both the reheating of the water sample from the uppermost zone of the salt brine to the in-situ-temperature as well as by the mixing of the water sample with normal Red Sea water. The iron and manganese delivered by the hot spring is separated within the area of the salt brine by their different redox-potentials. Iron is sedimented to a high amount within the salt brine, while, as evidenced by its small amounts in all sediment samples, the more easily reducible manganese is apparently carried out of the area before sedimentation can take place. The very good layering of the salt brine may be the result of the rough bottom topography with its several progressively higher levels allowing step-like enlargements of the surface areas of each successive layer. Each enlargement results in larger boundary areas along which more eff ective heat transfer and mixing with the next layer is possible. In the sediment samples up to 37.18% Fe is found, mostly bound as very poorly crystallized iron hydroxide. Pyrite is present in only very small amounts. We assume that the copper is bound mostly as sul­fide, while the zinc is most likely present in an other form. The sulfur-isotope-investigations indicate that the sulfur in the sediment, bound as pyrite and sulfides, is not a result of bacterical sulfate-reduction in the iron-rich mud of the Atlantis II-Deep, but must have been brought up with the hot brine.

Description: As a result of the participation of R. V. "Meteor" in the International Indian Ocean Expedition during the winter 1964/65 altogether 37 sounding profiles were obtained in the Arabian Sea (plate 2-18). They are showing the topographic peculiarities of the main features of the sea bottom in this northwestern part of the Indian Ocean: Shelves, continental slopes and rises, deep-sea plains and hills, the Mid-Oceanic Ridge, fracture zones and seamounts. A control chart (plate 1) shows the geographical sounding lines. The coordination of the soundings with the bathymetric sketch and the map of physiographic provinces (B. C. HEEZEN and M. THARP) is represented in fig. 1 and 2. All soundings were obtained by the modern ELAC-Narrow Beam sounder which also accurately records very steep slopes of the sea bottom (fig. 3 and 4 ). Two series of sounding prnfiles (fig. 5 and 6) are showing the main topographic differences of shelf and slope between the eastern African and the western Indian continental margin. The descriptive analysis of all the sounding sections carried out by "Meteor" show the following main results: a) discovery of a very steep towering up seamount in the northern Somali basin at φ = 8° 16' N, λ 53° 12' E, which is rising up from a depth of 5000 m to about -2000 m (plate 3), b) registration of numerous steep canyons in the upper part of the eastern African continental slope near the coast of Kenya (plate 6 ), c) complete representation of a characteristic section across the Carlsberg-Ridge inclusively rift mountains and the Rift-Valley (plate 9), d) new characteristic results of sounding profiles across the Alula-Fartak trench showing very steep siopes on its flancs (plate 18).

Description: Sediments from a 3.40 m core out of the Persian Gulf were investigated for their content of straight chain paraffins and fatty acids. The samples range in age between 2000 and 9000 years (C-14-age of organic C). They contain 100-300 ppm of extractable fatcompounds and 20-70 ppm of hydrocarbons. There is no connection between the original distribution of the homologous series of n-fatty acids and n-paraffins. However, there is evidence that part of the n-fatty acids was reduced to n-paraffins, although the sediment itself does not look as if it were deposited under reducing conditions.

Description: 1. Coeloplana meteoris is described as a new platyctene ctenophore (with 11 photographs and 1 coloured figure). 2. Its systematic position is discussed and understood as preliminary. 3. A comparison is made of the gastrovascularsystem of the Platyctenea. These can be used for systematic characterisation.

Description: During the expedition of R.V. "Meteor" to the Indian Ocean 21 species of marine algae and 2 phanerograms were collected on the Sarso islands. A littoral zone (in the botanical sense) and three sublittoral zones could be diffentiated by means of the algae. Of these the most conspicuous is the Sargassum-Turbinaria belt. A small strip of Avicennia mangrove was observed. The collected marine plants belong to 5 types of geographical distribution which indicate the origin of the flora from the Indian Ocean.

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: During the 1965 Atlantic Expedition the R/V "Meteor" was stationed on the equator for several weeks. In order to obtain the vertical flux of heat and momentum vertical profiles of dry and wet bulb temperatures and of wind speed were measured. The water temperature, and the dry and wet bulb temperatures of aspirated psychrometers were taken by means of platinum resistance thermometers. The wind speeds were obtained by contact anemometers and small generator type anemometers. The instruments were mounted at heights between 1 m and 9 m at a meteorological buoy. Connected by floating cables the buoy lay 300 m away from the ship, free of its disturbances.

Description: The meteorological and aeronomical programs of the "Atlantic Expedition 1965 (IQSY)" of the research vessel "Meteor" (10.8.-16.12.1965) are described. Several ionospheric parameters were measured on two meridian sections (fig. 2) and an anchor station at the crossing of the geographic and geomagnetic equator (15.9.-11.10.1965). One part of the aerological programs was to investigate the pressure-, temperature-, humidity- and wind-field of the atmosphere up to 38 km height (349 ascents) and at the equator its daily variations (8 ascents per day at 4 days, 6 ascents per day at 11 days). A second program was concerned with the finestructure of the lower troposphere, especially in the system of the tradewind (146 ascents with special temperature- and humiditysondes up to 5000 m and 63 ascents with a three-channel-sonde from captive balloons (fig. 1) or kites up to 2000 m). All components of the energy-balance of the atmosphere were measured (fig. 3). The radiationbalance up to 25 km height was studied with 26 albedo-radiosondes (A) and 58 infraread-radiosondes (B). The extinction and the atmospheric water-vapour-content (C) was measured by an interference-filter actinograph which was fixed at the sun by a photo-electric follower. The radiation balance of the sea-surface.(D,E), the vertical fluxes of momentum and of sensitive and latent heat (F), and profiles of tritium were studied at the anchor-station with a floating buoy 300 m upwind of the ship. At the same time the diurnal variation of airtemperature at 140 m height was obtained by the three-channel-sonde. The radioactivity of air, rain and ocean water, the tritium content of air in two heights and of ocean water in different depths were measured during the whole expedition. Similar determinations were made of the concentration of C14. The content of C02 of the air was recorded, S02, N02 and NO were discontinuously measured. The electric field-strength up to 15 km heights was measured to evaluate the voltage between ionosphere and earth (25 radiosondes). Continuous records of the atmospheric electric field-strength were made on board the ship and during parts of the expedition additionally the ionconcentration and free electric charge was determined. By the weatherstation of "Meteor" routine meteorological observations were taken supplemented by hourly cloud photographs during daytime. In the region of the trade-wind and the intertropical convergence by aid of the ship's weather radar films and photographs of the horizontal and vertical structure of clouds and showers were made. The results of the investigations will be published in this series.

Description: During the IQSY-expedition of FS "Meteor" at the equatorial station water surface temperature was measured by a radiation thermometer. The error given by this method is estimated. The measured daily variation is in rather good agreement with that calculated for an ocean, which is mixed upto the surface.

Description: In the atmosphere the solar radiation will not only be scattered and be absorbed by the absorption bands of the atmospheric gases but will also be diminished by continuum-absorption in the spectral regions without selective absorption - the "windows" -. The cause of this continuum-absorption is still unknown; may be it is caused by the aerosol or the wings of far off absorption lines. During the Atlantische Expedition 1965 of the research vessel "Meteor" an optical equipment was used for spectral determination of the direct solar radiation and the scattered solar radiation reaching the detector from various parts of the sky. The continuum-absorption follows by comparing the measured radiation with the radiation calculated under the assumption that there is no continuumabsorption. First time air masses without continental aerosol were investigated.

Description: This is a description of a radiosonde equipment for measuring the air-pressure, temperature and humidity simultaneously and continuously. The radiosonde consists of 3 audio-frequency sinewave generators having frequencies proportional to the measured values of a dry-bulb and a wet-bulb resistance thermometer and a pair of aneroid chambers. After receiving the radiosonde signal the 3 audio-frequencies are separated by filters, connected to 3 frequency meters and finally recorded on a double function plotter or on other strip-chart recorders. This equipment has been used for meteorological measurements in the lower troposphere using captive balloons on the research vessel "Meteor" during the 1965 Atlantic Expedition. More than 100 vertical soundings have been recorded up to a maximum ceiling of 2OOO m. The weight of the radiosonde including batteries for 5 hours recording is 1.1 kg. The ambient temperature may be in a range from -28 °C to +60 °C. The accuracy of measurement for the temperatures is ±0.1 °C in a range of 25 °C, for the pressure it is better than ± 1 mb in a range of 300 mb. The resolution for measuring short time changes in smaller ranges is considerably greater.

Description: After a short survey of the ionospheric observations made during the expedition special experiments on and near the geomagnetic equator are described. Using the mobility of the ship together with the form of the antenna pattern the structure of the equatorial Es -layer (Esq) was investigated. It was shown that the Esq-layer contains a filamentary structure which is orientated along the magnetic field lines of the earth. Further polarisation experiments were made in order to investigate the attenuation or blanketing of either the ordinary or the extraordinary component of a magneto-ionic wave. This attenuation and blanketing of the components can be observed conveniently in the vicinity of the geomagnetic equator since the polarisations of both components are linear in this region. Our measurements have shown that during daytime the directions of maximum suppression for the ordinary and the extraordinary component were not exactly perpendicular to each other but deviated from orthogonality by a small angle. This effect was interpreted as an influence of electron collisions on the polarization in the lower ionosphere. Finally a special 2 · F-propagation mode was found in performing these polarisation experiments. In this mode one hop: ground - ionosphere - ground is passed as an ordinary wave, the other as an extraordinary wave. Such a mode can exist only when a coupling between the two gyromagnetic waves is present. An example is shown in which the coupling is possibly caused by two different effects, namely 1. the gyromagnetic components are not perpendicular to each other in the lower ionosphere and 2. the filaments in the Esq-layer act as depolarizers.

Description: A phytoplankton net is described with which samples from six different depth zones can be obtained by a single vertical haul. The closing net is released by an electromagnet through single conductor wire (220 V D.C.). On a revolving disc which is driven by a spring, there are six buckets which are successively brought before the net opening. The parts made of bolting silk can be exchanged, the entrance opening can be reduced. The apparatus is independent from depth by means of pressure compensation.

Description: Within the frame of the German research vessel "Meteor" participation in the International Indian Ocean Expedition 8 members of the "litoral group" worked on a biological survey of the shores of the Sarso Islands (Farasan Archipelago) from 24.11. to 8.12.1964. This report gives details about the expedition and deals with organisation and technical supplies.

Description: The scope of this research was to find out, how important is the presence of brackish water for the formation of the characteristical littoral subsoil fauna in the interstitial spaces of beaches. There is little precipitation in the Red Sea area and therefore little influence of freshwater on the beach. Moreover, the sandy beach of Sarso Island (Farasan Archipelago) is bordered landwards and underneath by solid limestone, preventing subsoil fresh water, if there is any, from penetrating into the beach region. The salinity of the interstitial water from Sarso beach lies a little above the salinity of the adjacent sea. The microfauna of Sarso beach is composed to a rather big proportion of such species that are known to be characteristical littoral subsoil water species, partially of world wide distribution. The ecological analysis of this fauna, i. e. the freeliving Nematodes, reveals the presence of two distinct associations: 1. the association of the low level subsoil region, close to the sea, with clear interstitial water, subject to regular exchange with the water of the adjacent sea. 2. the association of the high level subsoil region, 4-10 meter distant from the sea, with brownish water. Contrary to earlier results there is no distinction in salinity between tl1e two associations, so it is not longer justified to apply the term brackish water fauna on the animals living in the association of the high level subsoil region.

Description: 1. The physiographical zones of the coast of the islands Sarso and Sindi Sarso (Farsan Archipelago, Red Sea) were analyzed by 3 profiles. As shore types a steep coast with an eroded eulitoral platform, a steep coast without such a platform and a sandbeach were selected. 2. The most conspicuous and characteristic fishes, invertebrates and algae were identified, their distribution and zonational limit were studied. 3. In contrast to a normal fringing reef the whole litoral area of these islands is of coral origin. The islands themselves are raised subfossil reefs from the early pleistocene or late tertiary. The recent reefs are based on eroded platforms of these subfossil reefs. 4. Terrestially and subaquatically there are distinguishable different water level marks. They may be the result not only of tectonic occurrences, but also of eustatic changes of the sea-level by glacial origin. 5. The litoral area along the NE coast of the island Sarso was mapped. The 3 zones were studied and described as cross-sections. 6. Samples of the characteristic lime stone of different zones were studied and identified as of only corallogene. 7. As profile II is distinguished from profile I only by the sedimentation of sand upon the eroded platform along the beach there arc great morphological and ecological differences between profile I and III. 8. A reconstruction of the reef development of profiles I and III by raising sea-level was tried. Despite the morphological differences there are many important geological coincidences.

Description: Acentrogobius meteori is a new species of the family Gobiidae. It was found on the coast of the island Sarso of the Farsan Archipelago (Red Sea). It seems to be related to the species A. baltea, decoratus, leptochilus, and reichei. The new gobiid fish lives within the eulitoral and upper sublitoral.

Description: Ospreys were observed during November and December at various areas of the Red Sea and the Gulf of Aden, where the bird is fairly abundant at suitable localities. Territorial behaviour is little developed, and sometimes up to six birds join in mating flights. Since trees are not available, the nest is built on the ground, preferably on prominent cliffs, and is composed of anything suitable (wood cast ashore, vegetable matter, human refuse, bones of turtles, carcasses of gannets). In the Red Sea the osprey was observed to feed exclusively on fish (Serranidae, Belone, Hemirhamphus, Calyodon, Carangidae, Lutianidae.) Gannets (Sula leucogaster) are breeding close to the ospreys but are never attacked.

Description: At the shores of the islands of Sarso and Sindi Sarso (Farasan Archipelago, Red Sea) the supra-, mid- and sublittoral zones of four different localities were investigated. Cross sections of a sand-rock beach, a rock beach, a rocky cliff and a mangrove beach have been drawn to find out different habitats. The largest part of the bottom is formed by creviced coral rocks. Fishes of the families Salariidae and Gobiidae were examined in detail and referred to distinct habitats. The habits and ecological demands of the species mentioned are discussed: Salariidae: Lophalticus kirkii prefers the supralittoral region of the steep cliffs, from which it can easily reach the water level. Feeds on algae. Istiblennius edentulus inhabits the horizontal as well as the vertical rock walls of the midlittoral region. Periods of low tide are passed in tide pools. Goes ashore only at night and feeds on algae. - Halmablennius flaviumbrinus occurs on the horizontal rock walls of the midlittoral region only. Periods of low tide are passed in tide pools, too. Feeds on algae. Antennablenius bypenetes exists on plain and steep rocks of the midlittoral region and prefers holes of adequate diameter to hide in. Periods of low tide are spent in little tide pools. Feeds on algae. Salarias fasciatus is very common in those parts of the sublittoral region where sufficient hiding-places are present. It seems to avoid turbulent water. Feeds on algae, eventually Bryozoa, too. Gobiidae: Acentrogobius ornatus and A. meteori live in the midlittoral and upper sublittoral regions on sand or in sand-filled trenches of horizontal rock walls. Cryptocentrus: species of this genus are very common below the midlittoral region. Since they are living in sand burrows, they are dependent on sandy areas. It is discussed, why Salariidae and Gobiidae prefer different environments in their trend towards an amphibian habit. On the rocky shores there seems to be a more favorable food supply for the algae-feeding Salariidae than for the predatory Gobiidae; the representatives of Gobiidae have turned to terrestrial habits in the mangrove region, less at rocky shores.

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.