Comparison of Estimated and Measured Marine Surface Wind Speed

A large portion of marine surface wind data is based on Beaufort estimates made subjectively from the visual appearance of the sea surface. At the time being, beaufort number from several decades are converted to wind speed by one equivalent scale. Application of a revised scientific equivalent scale (Kaufeld, 1981) to wind estimates of the period after World War II eliminates

Meridional temperature fluxes in the subtropical eastern North Atlantic

In a regional study of the eastern North Atlantic Ocean east of 35°W between 41°N and 8°N the mean meridional ocean temperature flux was computed from oceanographic and meteorological measurements using the direct method. In the area of the permanent subtropical gyre between 36°N and 22°N, a southward geostrophic temperature flux dominates. The Ekman temperature flux is weak and changes from a southward flux north of 32°N to a northward flux south of 32°N. In the area of the North Equatorial Current and in the tropics the Ekman temperature flux is comparable in magnitude to the geostrophic temperature flux. Therefore, the total temperature flux changes to a northward direction at 20°N, where the geostrophic transport is still to the south, and becomes large in the tropics, where both components show northward temperature fluxes. The heat flux divergence for the area investigated leads to an ocean heat gain of 0.19 PW. A comparison of annual mean temperature fluxes with temperature fluxes of east-west CTD sections from the winter half-year shows a small seasonal signal in the geostrophic temperature flux in the subtropical gyre but large differences in the tropics. The seasonal changes for the Ekman temperature fluxes are weak

Seasonal variability of meridional temperature fluxes in the eastern North Atlantic Ocean

Seasonal meridional ocean temperature fluxes were computed in a regional study of the eastern North Atlantic Ocean east of 30°30′W between 12°30′N and 39°30′N for the upper 1500 m of the ocean. Historical oceanographic and meteorological measurements are the data base for the direct method of computing temperature fluxes. Seasonal changes in temperature fluxes caused by the seasonality of Ekman transport and geostrophic transport are strongly dependent on latitude. Between 19N and 25N the meridional temperature flux shows low seasonality. In this area the permanent subtropical gyre and the stable trade-winds result in low seasonal changes. North of 25N the Ekman transport shows large seasonal variations. The latitude of the transition of southward Ekman temperature flux to northward Ekman temperature flux is located at 28N in winter. In summer it is found at 38N. The seasonal variability of the meridional temperature fluxes in the subtropics north of 25N is influenced by this annual cycle in Ekman transport, as well as by the southward displacement in summer and the northward movement of the Azores Current in winter. The tropical eastern Atlantic Ocean shows seasonal changes both in the geostrophic and Ekman transports. South of 17N the total temperature flux is always to the north. The largest meridional temperature fluxes, with more than 0.7 PW, are found in fall at 12°30′N directed northward, and in winter at 33°30′N to the south. In general the subtropical eastern North Atlantic Ocean transports heat to the south all the year round, while in the tropics heat is transported to the north. The seasonality in the eastern Atlantic Ocean is found to be different from seasonal variations in global investigations. The seasonal heat budget computations show a heat gain in the ocean in the area investigated from April to September and a heat loss from October to March. Over the whole year the eastern North Atlantic gains about 0.09 PW from the atmosphere

The WHIRLY proteins from Arabidopsis thaliana

Im Mittelpunkt der Arbeit stehen die Lokalisation und die Funktionen der Proteine WHIRLY1 und WHIRLY3 von Arabidopsis thaliana. Es konnte gezeigt werden, dass das dual lokalisierte Protein WHIRLY1 aus den Plastiden in den Zellkern umverteilt wird. Neben WHIRLY1 besitzt A. thaliana mit WHIRLY3 ein zweites plastidäres WHIRLY-Protein. Ergebnisse aus der vorliegenden Arbeit deuten auf eine zusätzliche Lokalisation von WHIRLY3 in den Mitochondrien hin. Eine Doppelmutante, die gleichzeitig Mutationen in den Genen WHIRLY1 und WHIRLY3 besitzt, zeigte bei Anzucht unter höheren Lichtintensitäten eine gestörte Entwicklung der Chloroplasten. Untersuchungen zur Keimung ergaben, dass Samen von why1-Mutanten sowohl unempfindlich gegenüber Salicylsäure als auch gegenüber Abscisinsäure sind. Mit einem Hemmstoff konnte gezeigt werden, dass Salicylsäure die Keimung inhibiert, indem sie die Synthese von Abscisinsäure fördert. WHIRLY1 ist also wichtig für die Wahrnehmung von Salicylsäure und Abscisinsäure während der Keimung. Untersuchungen mit transgenen Linien, in denen das WHIRLY1-Protein entweder in Plastiden und dem Zellkern oder nur im Zellkern akkumuliert, zeigten, dass spezifisch die plastidäre Form von WHIRLY1 die Empfindlichkeit von Samen gegenüber Abscisinsäure erhöht. WHIRLY1 ist daher an der Wahrnehmung von Abscisinsäure in Plastiden beteiligt. Das WHIRLY1-Protein wird als Kandidat für die Übertragung von Plastidensignalen zum Zellkern diskutiert.Es wurde gezeigt, dass WHIRLY1 an der Übertragung retrograder Signale beteiligt ist.This study focuses on the localization and functions of the WHIRLY1 and WHIRLY3 proteins from Arabidopsis thaliana. It was shown that the dually located WHIRLY1 protein is redistributed from plastids to the nucleus. In addition to WHIRLY1, A. thaliana has a second plastid WHIRLY protein named WHIRLY3. WHIRLY3 was shown to be dually localized to plastids and mitochondria. Plants having mutations in the genes WHIRLY1 and WHIRLY3 show disturbed chloroplast development when grown under elevated light intensities. Germination assays showed that why1 mutants are less sensitive towards salicylic acid as well as abscisic acid. It was shown that salicylic acid inhibits germination by promoting the synthesis of abscisic acid. Accordingly, WHIRLY1 is crucial for salicylic acid and abscisic acid perception during germination. Experiments with transgenic lines, that accumulate WHIRLY1 in plastids and the nucleus or in the nucleus alone, indicate that it is the plastid located isoform of WHIRLY1 which enhances the responsiveness of seeds towards abscisic acid. Hence, WHIRLY1 is important for perception of abscisic acid inside plastids. It was shown that WHIRLY1 can transmit plastid retrograde signals