Radium concentration in water samples from the Northeast Atlantic

We present field measurements of air-sea gas exchange by the radon deficit method that were carried out during JASIN 1978 (NE Atlantic) and FGGE 1979 (Equatorial Atlantic). Both experiments comprised repeated deficit measurements at fixed position over periods of days or longer, using a previously descibed precise and fast-acquiaition, automatic radon measuring system. The deficit time series exhibit variations that only partly reflect the expected changes in gas transfer. By evaluating averages over each time series we deduce the following gas transfer velocities (average wind velocity and water temperature in parentheses): JASIN phase 1: 1.6 ± 0.8 m/d (at ~6 m/s, 13°C) JASIN phase 2: 4.3 ± 1.2 m/d (at ~8 m/s, 13°C) FGGE: 1.2 ± 0.4 m/d (at ~5 m/s, 28°C) 0.9 ± 0.4 m/d (at ~7 m/s, 28°C) 1.5 ± 0.4 m/d (at ~7 m/s, 28°C) The large difference betwen the JASIN phase 2 and FGGE values despite quite similare average wind velocity becomes even larger when the values are, however, fully compatible with the range of gas transfer velocities observed in laboratory experiments and the conclusion is suggested that their difference is caused by the highly different wind variability in JASIN and FGGE. We conclude that in gas exchange parameterization it is not sufficinent to consider wind velocity only. A comparison of our observations with laboratory results outlines the range of variations of air-sea gas transfer velocities with wind velocity and sea state. We also reformulate the radon deficit method, in the light of our observed deficit variations, to account explicitely for non-stationary and horizontal inhomogeneity in previous radon work introduces considerable uncertainty in deduced gas transfere velocity. We furthermore discuss the observational rewuirements that have to be met for an adequate exploitation of the radon deficit method, of which an observation area of minimum horizontal inhomogeneity and monitoring of the remaining inhomogeneities are thought to be the most stringent ones.

Composition and properties of rocks and sediments from the Cape Verde fracture zone

The book presents results of comprehensive geological and geophysical studies, carried out in the Cape Verde fault zone in the 3-rd cruise of R/V Akademik Nikolaj Strakhov (1986). Detailed characterization of bottom relief, thickness and structure of the sedimentary cover, magnetic field, crust structure, lithology and stratigraphy of sediments, petrography and geochemistry of magmatic rocks. Conclusions about tectonic layering of the crust and upper mantle in the fault zone, and about a concurrent structural section of large mantle inhomogeneities have been done. The book is the first monographic description of a major fault structure of the ocean floor.

Monthly and yearly mean air temperature from 1829 to 2005 calculated from meteorological observations at different locations in Bremen, northern Germany

The secular record of annual mean temperatures of Bremen shows that inhomogeneities - especially caused by station transfers - lead to serious problems concerning the interpretation of climatic trends or fluctuations. Especially two transfers of the meteorological observing station in Bremen within our century - 1935/36 and 1978 - caused significant inhomogeneities, well documented by parallel measurements for several years. Obviously the stagnation of the temperature level of the original data set is a result of these transfers. The homogenized record version reveals a significant warming trend of about 1 Kelvin within the last century.