ALBERT

Beschreibung: Am Süd-Ausgang des Roten Meeres entstehen unter idealen Wachstumsbedingungen fast reine Korallen-Saumriffe, die als dünne Platten oft kilometerweit mit einer Geschwindigkeit von Zentimetern pro Jahr auf ihrem Schutt von der Küste horizontal gegen das Meer vorwachsen. Aufgetauchte Saumrifte, ein flacher Bootskanal oder abradierte Riffoberflächen weisen auf pleistozäne und jüngere Meeresspiegelschwankungen bzw. tektonische Verstellungen hin. Von einer gewissen Breite an bilden sich auf den Riffen Inseln in Form langgestreckter Rücken aus Korallensand, hinter denen sich stellenweise Mangrove ansiedelt oder Salze in flachen Lagunen abscheiden. Schließlich kann der Strand auf das Saumriff vorverlegt und dieses in die Küstenebene einbezogen werden.

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 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.

Beschreibung: 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.