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.