ALBERT

Description: In Ammassalik, in southeast Greenland, downslope winds can reach hurricane intensity and represent a hazard for the local population and environment. They advect cold air down the ice sheet and over the Irminger Sea, where they drive large ocean–atmosphere heat fluxes over an important ocean convection region. Earlier studies have found them to be associated with a strong katabatic acceleration over the steep coastal slopes, flow convergence inside the valley of Ammassalik, and—in one instance—mountain wave breaking. Yet, for the general occurrence of strong downslope wind events, the importance of mesoscale processes is largely unknown. Here, two wind events—one weak and one strong—are simulated with the atmospheric Weather Research and Forecasting (WRF) Model with different model and topography resolutions, ranging from 1.67 to 60 km. For both events, but especially for the strong one, it is found that lower resolutions underestimate the wind speed because they misrepresent the steepness of the topography and do not account for the underlying wave dynamics. If a 5-km model instead of a 60-km model resolution in Ammassalik is used, the flow associated with the strong wind event is faster by up to 20 m s−1. The effects extend far downstream over the Irminger Sea, resulting in a diverging spatial distribution and temporal evolution of the heat fluxes. Local differences in the heat fluxes amount to 20%, with potential implications for ocean convection.

Description: We perform eddy-resolving and high-vertical-resolution numerical simulations of the circulation in an idealized equatorial Atlantic Ocean in order to explore the formation of the deep equatorial circulation (DEC) in this basin. Unlike in previous studies, the deep equatorial intraseasonal variability (DEIV) that is believed to be the source of the DEC is generated internally by instabilities of the upper ocean currents. Two main simulations are discussed: Solution 1, configured with a rectangular basin and with wind forcing that is zonally and temporally uniform; and Solution 2, with realistic coastlines and with an annual cycle of wind forcing varying zonally. Somewhat surprisingly, Solution 1 produces the more realistic DEC: The large-vertical-scale currents (Equatorial Intermediate Currents or EICs) are found over a large zonal portion of the basin, and the small-vertical-scale equatorial currents (Equatorial Deep Jets or EDJs) form low-frequency, quasi-resonant, baroclinic equatorial basin modes with phase propagating mostly downward, consistent with observations. We demonstrate that both types of currents arise from the rectification of DEIV, consistent with previous theories. We also find that the EDJs contribute to maintaining the EICs, suggesting that the nonlinear energy transfer is more complex than previously thought. In Solution 2, the DEC is unrealistically weak and less spatially coherent than in the first simulation probably because of its weaker DEIV. Using intermediate solutions, we find that the main reason for this weaker DEIV is the use of realistic coastlines in Solution 2. It remains to be determined, what needs to be modified or included to obtain a realistic DEC in the more realistic configuration.

Description: A yet unexplained drift of (some) oxygen optodes during storage/transport and thus significant deviations from factory/laboratory calibrations have been a major handicap for autonomous oxygen observations. Optode drift appears to be systematic and is predominantly a slope effect due to reduced oxygen sensitivity. A small contribution comes from a reduced luminophore lifetime, which causes a small positive offset. A reliable in situ reference is essential to correct such a drift. Traditionally, this called for a ship-based reference cast, which poses some challenges for opportunistic float deployments. This study presents an easily implemented alternative using near-surface/in-air measurements of an Aanderaa optode on a 10-cm stalk and compares it to the more traditional approaches (factory, laboratory, and in situ deployment calibration). In-air samples show a systematic bias depending on the water saturation, which is likely caused by occasional submersions of the standard-height stalk optode. Linear regression of measured in-air supersaturation against in-water supersaturation (using ancillary meteorological data to define the saturation level) robustly removes this bias and thus provides a precise (0.2%) and accurate (1%) in situ correction that is available throughout the entire instrument’s lifetime.

Description: Predictability on seasonal time scales over the North Atlantic–Europe region is assessed using a seasonal prediction system based on an initialized version of the Max Planck Institute Earth System Model (MPI-ESM). For this region, two of the dominant predictors on seasonal time scales are El Niño–Southern Oscillation (ENSO) and sudden stratospheric warming (SSW) events. Multiple studies have shown a potential for improved North Atlantic predictability for either predictor. Their respective influences are however difficult to disentangle, since the stratosphere is itself impacted by ENSO. Both El Niño and SSW events correspond to a negative signature of the North Atlantic Oscillation (NAO), which has a major influence on European weather. This study explores the impact on Europe by separating the stratospheric pathway of the El Niño teleconnection. In the seasonal prediction system, the evolution of El Niño events is well captured for lead times of up to 6 months, and stratospheric variability is reproduced with a realistic frequency of SSW events. The model reproduces the El Niño teleconnection through the stratosphere, involving a deepened Aleutian low connected to a warm anomaly in the northern winter stratosphere. The stratospheric anomaly signal then propagates downward into the troposphere through the winter season. Predictability of 500-hPa geopotential height over Europe at lead times of up to 4 months is shown to be increased only for El Niño events that exhibit SSW events, and it is shown that the characteristic negative NAO signal is only obtained for winters also containing major SSW events for both the model and the reanalysis data.

Description: Classical theory concerning theEliassen–Palmrelation is extended in this study to allowfor a unified treatment of midlatitude inertia–gravity waves (MIGWs), midlatitude Rossby waves (MRWs), and equatorial waves (EQWs). A conservation equation for what the authors call the impulse-bolus (IB) pseudomomentum is useful, because it is applicable to ageostrophic waves, and the associated three-dimensional flux is parallel to the direction of the group velocity of MRWs. The equation has previously been derived in an isentropic coordinate system or a shallow-water model. The authors make an explicit comparison of prognostic equations for the IB pseudomomentum vector and the classical energy-based (CE) pseudomomentum vector, assuming inviscid linear waves in a sufficiently weak mean flow, to provide a basis for the former quantity to be used in an Eulerian time-mean (EM) framework. The authors investigate what makes the three-dimensional fluxes in the IB and CE pseudomomentum equations look in different directions. It is found that the two fluxes are linked by a gauge transformation, previously unmentioned, associated with a divergence-form wave-induced pressure L. The quantity L vanishes for MIGWs and becomes nonzero for MRWs and EQWs, and it may be estimated using the virial theorem. Concerning the effect of waves on the mean flow, L represents an additional effect in the pressure gradient term of both (the three-dimensional versions of) the transformed EM momentum equations and the merged form of the EMmomentumequations, the latter of which is associated with the nonacceleration theorem.

Description: [in “State of the Climate in 2014” : Special Supplement to the Bulletin of the American Meteorological Society Vol. 96, No. 7, July 2015]

Description: Atmospheric deposition contributes potentially significant amounts of the nutrients iron, nitrogen and phosphorus (via mineral dust and anthropogenic aerosols) to the oligotrophic tropical North Atlantic Ocean. Transport pathways, deposition processes and source strengths contributing to this atmospheric flux are all highly variable in space and time. Atmospheric sampling was conducted during 28 research cruises through the Eastern Tropical North Atlantic (ETNA) over a 12 year period and a substantial dataset of measured concentrations of nutrients and trace metals in aerosol and rainfall over the region was acquired. This database was used to quantify (on a spatial- and seasonal-basis) the atmospheric input of ammonium, nitrate, soluble phosphorus and soluble and total iron, aluminium and manganese to the ETNA. The magnitude of atmospheric input varies strongly across the region, with high rainfall rates associated with the Inter-tropical Convergence Zone contributing to high wet deposition fluxes in the south, particularly for soluble species. Dry deposition fluxes of species associated with mineral dust exhibited strong seasonality, with highest fluxes associated with winter-time low-level transport of Saharan dust. Overall (wet plus dry) atmospheric inputs of soluble and total trace metals were used to estimate their soluble fractions. These also varied with season and were generally lower in the dry north than in the wet south. The ratio of ammonium plus nitrate to soluble iron in deposition to the ETNA was lower than the N:Fe requirement for algal growth in all cases, indicating the importance of the atmosphere as a source of excess iron.

Description: We investigated the effect of hydrostatic pressure of up to 6000 dbar on Aanderaa and Sea-Bird oxygen optodes both in the laboratory and in the field. The overall pressure response is a reduction in the O2 reading by 3 – 4 % per 1000 dbar which is closely linear with pressure and increases with temperature. Closer inspection reveals two superimposed processes with opposite effect: an O2-independent pressure response on the luminophore which increases optode O2 readings and an O2-dependent change in luminescence quenching which decreases optode O2 readings. The latter process dominates and is mainly due to a shift in the equilibrium between sensing membrane and sea water under elevated pressures. If only the dominant O2-dependent process is considered, Aanderaa and Sea-Bird optodes differ in their pressure response. Compensation of the O2-independent process, however, yields a uniform O2 dependence for Aanderaa optodes with standard foil and fast-response foil as well as Sea-Bird optodes. A new scheme to calculate optode O2 from raw data is proposed to account for the two processes. The overall uncertainty of the optode pressure correction amounts to 0.3 % per 1000 dbar, mainly due to variability between sensors.

Description: The upper tropical Atlantic Ocean has markedly warmed since the 1960s. It has been shown that this warming was not due to local heat fluxes, and that the trade winds that drive the coastal and equatorial upwelling have intensified rather than weakened. Remote forcing might thus have played an important role. Here model experiments are used to investigate the contribution from an increased inflow of warm Indian Ocean water through Agulhas leakage. A high-resolution hindcast experiment with interannually varying forcing for the time period 1948 to 2007, in which Agulhas leakage increases by about 45% from the 1960s to the early 2000s, reproduces the observed warming trend. To tease out the role of Agulhas leakage, a sensitivity experiment designed to only increase Agulhas leakage is used. Compared to a control simulation it shows a pronounced warming in the upper tropical Atlantic Ocean. A Lagrangian trajectory analysis confirms that a significant portion of Agulhas leakage water reaches the upper 300m of the tropical Atlantic Ocean within two decades, and that the tropical Atlantic warming in the sensitivity experiment is mainly due to water of Agulhas origin. Therefore, it is suggested that the increased trade winds since the 1960s favor upwelling of warmer subsurface waters, which in parts originate from the Agulhas, leading to higher SSTs in the tropics

Description: Variations in the global tropospheric zonal mean zonal wind ([U]) during boreal winter are investigated using Rotated Empirical Orthogonal Functions applied to monthly means. The first two modes correspond to the Northern and Southern Annular Mode and modes 3 and 4 represent variability in the tropics. One is related to El Niño Southern Oscillation and the other has variability that is highly correlated with the time series of [U] at 150 hPa between 5°N and 5°S ([U150]E) and is related to activity of the Madden-Julian Oscillation. The extratropical response to [U150]E is investigated using linear regressions of 500 hPa geopotential height onto the [U150]E time series. We make use of reanalysis data and of the ensemble mean output from a relaxation experiment using the European Center for Medium Range Weather Forecasts model in which the tropical atmosphere is relaxed towards reanalysis data. The regression analysis reveals that a shift of the Aleutian low and a wave train across the North Atlantic are associated with [U150]E. We find that the subtropical waveguides and the link between the North Pacific and North Atlantic are stronger during the easterly phase of [U150]E. The wave train over the North Atlantic is associated with Rossby wave sources over the subtropical North Pacific and North America. Finally, we show that a linear combination of both [U150]E and the Quasi Biennial Oscillation in the lower stratosphere can explain the circulation anomalies of the anomalously cold European winter of 1962/63 when both were in an extreme easterly phase.

Description: To investigate the influence of atmospheric model resolution on the representation of daily precipitation extremes, ensemble simulations with the atmospheric general circulation model ECHAM5 at different horizontal (T213 to T31) and vertical (L31 to L19) resolutions and forced with observed sea surface temperatures and sea ice concentrations have been carried out for 01/1982 - 09/2010. All results have been compared with the highest resolution, which has been validated against observations. Resolution affects both the representation of physical processes and the averaging of precipitation across grid boxes. The latter, in particular, smoothes out localized extreme events. These effects have been disentangled by averaging precipitation simulated at the highest resolution to the corresponding coarser grid. Extremes are represented by seasonal maxima, modeled by the generalized extreme value distribution. Effects of averaging and representation of physical processes vary with region and season. In the tropical summer hemisphere, extreme precipitation is reduced by up to 30% due to the averaging effect, and a further 65% owing to a coarser representation of physical processes. Towards mid- to high latitudes, the latter effect reduces to 20%; in the winter hemisphere it vanishes towards the poles. A strong drop is found between T106 and T63 in the convection dominated tropics. At the lowest resolution, northern hemisphere winter precipitation extremes, mainly caused by large scale weather systems, are in general represented reasonably well. Coarser vertical resolution causes an equatorward shift of maximum extreme precipitation in the tropics. The impact of vertical resolution on mean precipitation is less pronounced; for horizontal resolution it is negligible.

Description: Many aspects of the coupling between the ocean and atmosphere at the mesoscale (on the order of 20–100 km) remain unknown. While recent observations from the Southern Ocean revealed that circular fronts associated with oceanic mesoscale eddies leave a distinct imprint on the overlying wind, cloud coverage, and rain, the mechanisms responsible for explaining these atmospheric changes are not well established. Here the atmospheric response above mesoscale ocean eddies is investigated utilizing a newly developed coupled atmosphere–ocean regional model [Consortium for Small-Scale Modeling–Regional Ocean Modelling System (COSMO-ROMS)] configured at a horizontal resolution of ~10 km for the South Atlantic and run for a 3-month period during austral winter of 2004. The model-simulated changes in surface wind, cloud fraction, and rain above the oceanic eddies are very consistent with the relationships inferred from satellite observations for the same region and time. From diagnosing the model’s momentum balance, it is shown that the atmospheric imprint of the oceanic eddies are driven by the modification of vertical mixing in the atmospheric boundary layer, rather than secondary flows driven by horizontal pressure gradients. This is largely due to the very limited ability of the atmosphere to adjust its temperature over the time scale it takes for an air parcel to pass over these mesoscale oceanic features. This results in locally enhanced vertical gradients between the ocean surface and the overlying air and thus a rapid change in turbulent mixing in the atmospheric boundary layer and an associated change in the vertical momentum flux.

Description: This study examines the role of processes transporting tracers across the Polar Front (PF) in the depth interval between the surface and major topographic sills, which this study refers to as the “PF core.” A preindustrial control simulation of an eddying climate model coupled to a biogeochemical model [GFDL Climate Model, version 2.6 (CM2.6)– simplified version of the Biogeochemistry with Light Iron Nutrients and Gas (miniBLING) 0.1° ocean model] is used to investigate the transport of heat, carbon, oxygen, and phosphate across the PF core, with a particular focus on the role of mesoscale eddies. The authors find that the total transport across the PF core results from a ubiquitous Ekman transport that drives the upwelled tracers to the north and a localized opposing eddy transport that induces tracer leakages to the south at major topographic obstacles. In the Ekman layer, the southward eddy transport only partially compensates the northward Ekman transport, while below the Ekman layer, the southward eddy transport dominates the total transport but remains much smaller in magnitude than the near-surface northward transport. Most of the southward branch of the total transport is achieved below the PF core, mainly through geostrophic currents. This study finds that the eddy-diffusive transport reinforces the southward eddy-advective transport for carbon and heat, and opposes it for oxygen and phosphate. Eddy-advective transport is likely to be the leading-order component of eddy-induced transport for all four tracers. However, eddy-diffusive transport may provide a significant contribution to the southward eddy heat transport due to strong along-isopycnal temperature gradients.

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: S02 concentration and sulfate in maritime aerosols were analyzed during the Atlantic-expedition 1969 (GARP) as a contribution to the atmosphedc sulfurbudget. Discontinuous methods for analysis were applied. The results show with respect to S02 a decreasing concentration from the temperate latitudes towards the tropics, indicating continental origin of this trace-gas. The concentration of sulfate-aerosols reveals no meridional trend. The "background" concentration of sulfate-aerosols is composed of a continental and a maritime component.

Description: Data on the N20 content in air and water over the North Atlantic from 10° S to 60° N along 30° W are presented. The N20 mixing ratio in air shows low values for air masses originating from West Africa suggesting N20 sinks in these arid areas. The N20 concentration in surface water is 1.5 to 3 times higher than the equilibrium from the air indicating that this part of the Atlantic Ocean is a source for atmospheric N20. In deeper layers of the ocean there is an indication of N20 destruction.

Description: From 9th of March to 4th of May 1969 measurements of raindrops has been carried out at the Atlantic Expedition of the "Meteor". The main part (584) of the 720 spectra is measured in the zones near the equator. Normally the rainfalls contain only small drops and are very intensive. 676 spectra had been measured, which have 85 % of all drops per ms with a diameter smaller or equal to 1.25 mm. The intensities of these spectra grow up to 250.3 mm/h. Wide spectra are rare and always intensive (R greater 10.0 mm/h). The radarequation Z = aRb, calculated from R (intensity of rain [mm/h]) and Z (radarreflectivity [mm6/m3]) both of them deduced from our measurements, deviates from the usual form Z = 200 Rl.60 and has the value Z 137 Rl.26. The comparison of the spectra measured on border of the "Meteor" with these of the maritime station of high latitude Reykjavik and the station near equator Entebbe shows, that the spectra of the "Meteor" are more equal to these of Reykjavik as to these of Entebbe. This ist confirmed by the difference of the radar-equation, which is for Reykjavik Z = 106 Rl.2 3 and for Entebbe Z = 278 Rl.30.

Description: The equilibrium radii of mar1t1me aerosol particles are calculated for the purpose of describing quantitatively the changes in the standard visibility or in the scattering coefficient, which result from changes in the humidity. No assumptions are made with regard to particular particle size distributions. Changes in the density and in the refractive index of the aerosol droplets and insoluble ingredients are admitted. The results are illustrated with an aqueous NaCl-aerosol and are compared with the measurements of other authors. A close mathematical relationship is found to exist between the wavelength dependence of the scattering coefficient for haze and its changes with humidity. Applied to the measurements from the Atlantic "Meteor"-Expedition 1965, there follows a deformation of the oceanic particle size distributions in the range below 1 µm radius. Above 98 % humidity there result characteristic changes in the size distributions of any aerosol, which agree with frequently observed changes in time of the wavelength dependence of the atmospheric scattering coefficient.

Description: During the 14th expedition of the research vessel "Meteor" from the 2nd of July to the 7th of August 1968 continously recording instruments for measuring the C02 partial pressure of seawater and atmospheric C02 were developped by the Meteorological Institute, University of Frankfurt/M. During the Faroer expedition instrumental constants, such as relative and absolute accuracy, inertia and solvent power were tested. The performance of discontinous analyses of water samples was adopted to shipboard conditiones and correction factors depending on water volume, depth of sampling and water temperature were measured. After having computed average values of the continous records (atmosp. C02 content, C02 partial pressure, water temperature) geographical distribution, diurnal variation and dependence of diurnal averages were tested. At four different locations c02 partial pressure was measured in various depths. During the voyage from the Faroer islands to Helgoland the measured concentrations of atmospheric C02 content and C02 partial pressure were tested with respect to a correlation of the geographical latitude.

Description: The concentration of C02 in the layer of air near the ocean surface and in the surface water itself were measured continuously during the Atlantic Expedition of 1969. Of particular interest is the meridional profile of each component measured between 10° S and 60 ° N latitude at a constant longitude of 30° W. The variation with latitude of the vertical distribution of C02 partial pressure in water, as determined from the extensive data of Wattenberg (Meteor Expedition 1925 /27) and from five profiles resulting from the presently described expedition, helps explain the latitudinal dependence of the C02 content of Atlantic surface water. If one assumes an increase in the vertical mixing of the surface layers of the ocean due to surface cooling, as occurs in winter, then a seasonal trend to the partial pressure of the C02 in the surface water is to be expected north of about 40 ° N latitude. A spatial analog to such a temporal trend may be exemplified by the observation of gradually increasing Pco2 values with decreasing temperature as the measuring ship travelled northward from 40° N. The variation with latitude of the C02 concentration in the atmosphere has been found to be an order of magnitude smaller than that in the water, suggesting that the amount of C02 in the water has only a minor influence over the meridional distribution of C02 in the atmosphere.

Description: During the Atlantic Expedition of 1969 (GARP) on the research vessel "Planet" measurements of the vertical profile of the C02-concentration in the lower atmospheric layers were made. For these measurements a special apparatus was develloped which is described.

Description: During the third part of the Atlantic Expedition 1969 from 10° S to 60° N along 30 ° W, measurements of the complete size distribution of atmospheric aerosols over the whole size range from about 10-7 to 10-2 cm radius were made. This was possible by the simultaneous operation of different methods which are critically discussed. The results obtained are the first of its kind and are of general interest despite some methodical shortcomings. North of the equator the ship passed through air masses of West African origin and the influence of Sahara dust on the marine aerosols could be documented in a unique way. The Sahara dust component was restricted to the size range of 10-5 to 10-3 cm radius. Throughout the voyage particles up to 10-2 cm radius were always found to be present, similar to findings over continents. Of special interest is the observation that the size distribution extends to very small particles, suggesting continuous aerosol production over the ocean.

Description: Heterostegina depressa from the Persian Gulf was cultivated in the laboratory and observations were made on their zooxanthellae. The relation between the Heterostegina and the zooxanthellae living inside them is a symbiotic one. These foraminifera proved to be capable of growth when kept in the light without being given additional particulate nutrition. In this case the Heterostegina fed themselves partly by digesting the zooxanthellae. When kept in darkness the animals did not grow even if fed additionally. Fed as well as unfed foraminifera and also some of their zooxanthellae survived maintenance in darkness for a period of four months. Since the nucleus of the zooxanthellae is no dinocaryon and the cell membrane does not show any cellulose reaction and since the occurrence of pennate diatoms was observed in the culture vessels after the zooxanthellae had left the foraminifera test the zooxanthellae living in Heterostegina are possibly diatoms.

Description: Is it possible to draw a structural scheme of the West Mediterranean basin? The author gives a summary of the topographic, gravimetric, magnetic, seismic refraction and further on seismic profiling data for the last 40 years - the most important fact is the discovery of salt domes, but geophysics do not explain their origin and age. From a short survey of some geological observations on shore the extension of a landmass south of the Provence has been concluded during the oligocene. The question arises hether this mass is now the block of Corsica and Sardinia, which may have been later drifted to its actual position? - if so, the salt could be tertiary - or is this landmass as a part of the Provence sunken down under the sea by tectonic processes? If so one could propose a triassic age of the saltdomes. Continuous seismic profiling does not give any arguments for one of these two theories. But it allows us to follow the miocene surface and to know the variations of the thickness of the plioquaternary sedimentation. Many questions remain. The author lists the problems still to be solved and the necessary means. International cooperation may give the means for the solution of these problems.

Description: As part of the Atlantic Seamount Cruises 1967 with F.S. "Meteor" a topographic survey in the area of Great Meteor Seamount (φ = 30° 00' N, λ = 28° 30' W) was carried out from April 9th to May 1st and from May 31st to June 8th 1967. Shape and expansion of this seamount were generally known (fig. 1) but the form in detail was not yet identified by then. The length over all of the usable sounding sections with F.S. "Meteor" was 1930 nautical miles. Most of the track positions were taken by a relative reference system, that means a special navigation buoy with two radar reflectors (fig. 2). The echo soundings could be carried out with the ELAC Narrow Beam Sounder 1 CO ( extreme narrow-beam of ± 1,4° at 3 dB) giving an exact registration of even very steep slopes (fig. 3). As a result of the survey a detailed bathymetric chart of the Great Meteor Seamount could be designed ( original scale 1 : 250 000), here it is reproduced in a smaller scale (fig. 5). A model in 1:10 vertical scale exaggeration gives a general impression of the main topographical characteristics (fig. 4). It shows in the SW region of Great Meteor Seamount two other steep elevations discovered during the survey courses: Small Meteor Seamount (φ = 29° 41' N, λ = 28° 58' W) and Closs Seamount (φ = 29° 25' N, λ = 29° 08' W). Some typical sounding courses are represented in profiles (1:20 vertical scale exaggeration, fig. 6, table 1-8). Examples for slope inclination around the Great Meteor Seamount are given in a profile series exaggerated 1:10 (table 9). The Great Meteor Seamount consists of three morphological parts : a flat summit plateau (330 m - area about 1132 km2), steep slope (inclination about 13°, maximal 50°) and surrounding lower rise region (inclination 〈 5°). Terraces could be found in different depths at the steep slope of Great Meteor Seamount particularly at -450 m and - 550 m. Great and Small Meteor Seamount have the general shape of guyots or flattopped seamounts as described by HEss (1946), Closs Seamount shows the typical conic form of a submarine volcano. Small Meteor and Closs Seamount signify no terraces in their very steep slopes. The volume calculation based on the bathymetric chart gives the following rates : Great Meteor Seamount : 23842 km3, Small Meteor Seamount: 657 km 3, Closs Seamount about 212 km3.

Description: The description of the construction of the equipment is devided into two parts: 1. The remote controlled buoy with data-collection. 2. The telemetric buoy with telerepeating device. In the first case all equipment data-acquisition and -collection is inside the buoy itself. In the other case the seismic signals are transmitted over distances up to 200 km over sea. By the telerepeating device of the telemetric buoys the gain of the hydrofon-amplifier can be changed in steps. Thus it is possible to use the full scale of the dynamic range of the FM-Multiplex-Equipment.

Description: Living Heterostegina depressa were found in the Persian Gulf on shallows and sides of islands in the Central Basin. Preliminary culture experiments furnished information on life span, salinity tolerances and population density of the species. Reproduction processes (probably asexual) could be observed several times. A possible carbonate production of ca. 150g/year/m2 has been estimated.

Description: Die atlantischen ibero-marokkanischen Kontinentalhänge sind durch junge Tone bedeckt. Vor Portugal (Kap Sines) sind sie grau und sandarm, vor Marokko (Kap Mazagan) rötlichbraun bis rötlichgrau und sandreicher (Abb. 6). Die Mehrzahl der 19 untersuchten Sedimentkerne von im Wesentlichen 2 Profilen (Abb. 3) sind mit Hilfe der planktonischen Foraminiferen zu korrelieren (vgl. Abb. 27, 28). Hierfür eignen sich besonders die qualitative und die quantitative Verteilung der einzelnen Arten sowie Änderungen der Windungsrichtungen von drei Globorotalia-Arten: G. crassaformis, G. hirsuta und G. truncatulinoides. Im Holozän weisen Sedimente aus Wassertiefen um 2000 m vor Portugal die höchsten (bis 〉 20 cm/1000 Jahre), vor Marokko die niedrigsten Sedimentationsraten (um 3 cm/1000 Jahre) auf. Die Datierung beruht auf der Auswertung der planktonischen Foraminiferenfaunen sowie auf 31 Bestimmungen mit 14C und wird durch lithostratigraphische Untersuchungen gestützt. Ein methodisches Beispiel der Kern-Auswertung wird auf den Tab. 3-5 und den Abb. 23, 24 gebracht. Holozäne Faunen unterscheiden sich von den pleistozänen durch eine andere artliche Zusammensetzung sowie niedrigere Dominanzen und höhere Diversitäten. Ihre Foraminiferenzahlen schwanken auch weniger. Während im Pleistozän und im Holozän vor Marokko die Temperaturen des Oberflächenwassers sich nach den Faunen mit der Küstenentfernung nicht geändert haben, steigen sie vor Portugal im Holozän seewärts an (Abb. 31). Der Anteil wärmeliebender Arten ist vor Marokko jedoch durchweg höher. Das Plankton/Benthos-Verhältnis der Foraminiferenfaunen nimmt mit der Tiefe zu und erreicht schon in rund 1000 m Wassertiefe maximale Werte. Die Produktionsrate für planktonische Foraminiferen ist am Kontinentalrand höher als im offenen Ozean (Abb. 48). Umgekehrt werden ihre Gehäuse auch schon in Sedimenten aus Wassertiefen 1000 m merklich angelöst. Noch stärkere Anlösung tritt in der Tiefsee auf (Abb. 43). Vor Portugal ist sie dort im ausgehenden Pleistozän jedoch wesentlich geringer als im Holozän, weil offensichtlich der Zutritt polaren Tiefenwassers eingeschränkt gewesen ist. Ein zusammenfassender Vergleich beider Kontinentalränder findet sich in Tab. 10.

Description: The data of a topographical survey of the Great Meteor Seamount (during the Atlantische Kuppenfahrten 1967) are investigated statistically and show a significant frequency of systematical variations in the course of the slope in depths from 300 to 700 meters. This range is morphometrically analysed - inclination diagrams give information about the structure of the slope. Considering the results of other authors an interpretation of the observed terraces is attempted: in 450 m depth exists a barrier reef, especially in the N and E of the seamount; in about 550 m (particularly in the N and E) a series of steps can be proved; in 610 m depth a residual terrace extends from W to NNW. The interaction of eustatic changes in sea level with isostatic movements of the seamount leads to the various structure of the upper patt of the slopes. To interpret the 450 m-terrace as a coral reef, optimal conditions for vigorous growth of reef-forming corals are assumed during the Pre-pleistocene.

Description: In the course of the stratigraphical zonation of a deepsea core from the Arabian Sea, the porosity of Neogloboquadrina dutertrei was studied. Pore diameters (main factors of shell-porosity, which is a useful index of water temperature) strongly vary on the same fossil individuum. Systematic evaluation of foraminiferal microtopographies by scanning microscope yielded good correlation between pore-diameters and crystallinity of the wall. Micro-mapping of the lines of equal crystallinity and of porosity shows no relation to the spiral geometry of the living animal. Therefore, diagenesis is suggested as the factor changing the surface structures by recrystallisation. Through this process the pores can be closed introducing difficulties in the use of shell-porosity in fossil material.

Description: Well preserved pollen grains were found in samples of 17 profiles. An attempt was made to get a pollen diagram of a 1.9 m core from the Gulf of Iran. The lack of major fluctuations in the pollen content, however, showed that the vegetation did not change very much during the span of time represented in the sediments of that core. Besides spores of Adiantum cf. capillus veneris, 62 pollen types were listed. The average value of NAP is 88%. Chenopodiaceae and Artemisia are the most important pollen types. The typical vegetation of the coastal region and adjacent areas of Iran is well represented in the pollen content.