Christoph Willibald Gluck, Brustbild

Signatur des Originals: S 36/G03059

Christoph Willibald Gluck, Brustbild

Signatur des Originals: S 36/G03060

Christoph Willibald Gluck, Brustbild

Signatur des Originals: S 36/G03061

Christoph Willibald Gluck, Brustbild, Profil

Signatur des Originals: S 36/G03062

Christoph Willibald Gluck, Brustbild

Signatur des Originals: S 36/G03063

Christoph Willibald Gluck, Brustbild, Profil

Signatur des Originals: S 36/G03064

Christoph Willibald Gluck, Brustbild

Signatur des Originals: S 36/G03065

Georg Friedrich Händel, Brustbild - Christoph Willibald Gluck, Brustbild - Ignaz Pleyel, Brustbild

Signatur des Originals: S 36/G03117

Christoph Willibald Gluck, Brustbild

Signatur des Originals: S 36/G04041

Christoph Willibald Gluck, Brustbild

Signatur des Originals: S 36/G04042

Christoph Willibald Gluck, Brustbild

Signatur des Originals: S 36/G04043

Christoph Willibald Gluck, Brustbild

Signatur des Originals: S 36/G04044

Christoph Willibald Gluck, Ganzfigurbildnis

Signatur des Originals: S 36/G04569

Stable-isotope records from Dronning Maud Land, Antarctica

The European Project for Ice Coring in Antarctica (EPICA) includes a comprehensive pre-site survey on the inland ice plateau of Dronning Maud Land. This paper focuses on the investigation of the 18O content of shallow firn and ice cores. These cores were dated by profiles derived from dielectric-profiling and continuous flow analysis measurements. The individual records were stacked in order to obtain composite chronologies of 18O contents and accumulation rates with enhanced signal-to-noise variance ratios.These chronologies document variations in the last 200 and 1000 years.The 18O contents and accumulation rates decreased in the 19th century and increased during the 20th century.Using the empirical relationships between stable isotopes, accumulation rates and the 10m firn temperature, the variation of both parameters can be explained by the same temperature history.But other causes for these variations, such as the build-up of the snow cover, cannot be excluded. A marked feature of the 1000 year chronology occurs during the period AD 1180-1530 when the 18O contents remains below the long-term mean. Cross-correlation analyses between five cores from the Weddell Sea region and Dronning Maud Land show that 18O records can in some periods be positively correlated and in others negatively correlated, indicating a complex climatic history in time and space.

Horizontal profiles of longwave and shortwave radiation components over sea ice near Barrow, Alaska during the 2011 melt

An integrated instrument package for measuring and understanding the surface radiation budget of sea ice is presented, along with results from its first deployment. The setup simultaneously measures broadband fluxes of upwelling and downwelling terrestrial and solar radiation (four components separately), spectral fluxes of incident and reflected solar radiation, and supporting data such as air temperature and humidity, surface temperature, and location (GPS), in addition to photographing the sky and observed surface during each measurement. The instruments are mounted on a small sled, allowing measurements of the radiation budget to be made at many locations in the study area to see the effect of small-scale surface processes on the large-scale radiation budget. Such observations have many applications, from calibration and validation of remote sensing products to improving our understanding of surface processes that affect atmosphere-snow-ice interactions and drive feedbacks, ultimately leading to the potential to improve climate modelling of ice-covered regions of the ocean. The photographs, spectral data, and other observations allow for improved analysis of the broadband data. An example of this is shown by using the observations made during a partly cloudy day, which show erratic variations due to passing clouds, and creating a careful estimate of what the radiation budget along the observed line would have been under uniform sky conditions, clear or overcast. Other data from the setup's first deployment, in June 2011 on fast ice near Point Barrow, Alaska, are also shown; these illustrate the rapid changes of the radiation budget during a cold period that led to refreezing and new snow well into the melt season.