Description: Glacier surface mass-balance measurements on Greenland started more than a century ago, but no compilation exists of the observations from the ablation area of the ice sheet and local glaciers. Such data could be used in the evaluation of modelled surface mass balance, or to document changes in glacier melt independently from model output. Here, we present a comprehensive database of Greenland glacier surface mass-balance observations from the ablation area of the ice sheet and local glaciers. The database spans the 123 a from 1892 to 2015, contains a total of ~3000 measurements from 46 sites, and is openly accessible through the PROMICE web portal (http://www.promice.dk). For each measurement we provide X, Y and Z coordinates, starting and ending dates as well as quality flags. We give sources for each entry and for all metadata. Two thirds of the data were collected from grey literature and unpublished archive documents. Roughly 60% of the measurements were performed by the Geological Survey of Denmark and Greenland (GEUS, previously GGU). The data cover all regions of Greenland except for the southernmost part of the east coast, but also emphasize the importance of long-term time series of which there are only two exceeding 20 a. We use the data to analyse uncertainties in point measurements of surface mass balance, as well as to estimate surface mass-balance profiles for most regions of Greenland.

Description: To profile the ice cores being drilled from the EPICA Dronning Maud Land pre-site survey in terms of density and dielectric properties a combined analyses bench has been developed. All the firn and ice cores cored during the German activities, the ice cores brought to Europe from the surveys of the Nordic group and besides EPICA the German-Russian Sevemaya Zemlya core were analysed on the combined bench. 29 ice and firn cores with an added length of more than 1373 m passed through the bench. The yielded data and its interpretation are published in various journals, but the bench itself has not been described yet in the literature. Tue bench's new features are: (1)the combination of DEP and gamma-densimeter, (2)the adjustability of the core's position in the middle of the DEP electrodes and (3)the manageability of broken core in a setup with disposed core. With these special features the bench is a fast scanner for the determination of accumulation already in the field with improved DEP precision in the order of l%. This precision is exclusively achieved when remaining air gaps between the core and the electrodes are considered. Tue mathematical theory is lengthy, but the air gaps' effects will be illustrated with selected plots of calculated potential distributions within the electrodes. For the measurement the core is wrapped in a 20 micron thick plastic foil and suspended under a carrier. The carrier moves motor driven along a rail guide and stops at the scanners position - here gamma-densimeter and DEP - for the measurements to be taken. The paper's scope is to describe a fast precise scanner for accumulation determination and electrical profiles. Besides the detennination ofthose climatological parameters the dielectric profiles are input data for modeling radargrams and to test dielectric mixture models for snow, e.g. Looyenga's model. Some example datasets will be presented to illustrate the potentialities of the bench.

Description: Temperature changes in Antarctica over the last millennium are investigated using proxy records, a set of simulations driven by natural and anthropogenic forcings and one simulation with data assimilation. Over Antarctica, a long term cooling trend in annual mean is simulated during the period 1000-1850. The main contributor to this cooling trend is the volcanic forcing, astronomical forcing playing a dominant role at seasonal timescale. Since 1850, all the models produce an Antarctic warming in response to the increase in greenhouse gas concentrations. We present a composite of Antarctic temperature, calculated by averaging seven temperature records derived from isotope measurements in ice cores. This simple approach is supported by the coherency displayed between model results at these data grid points and Antarctic mean temperature. The composite shows a weak multi-centennial cooling trend during the pre-industrial period and a warming after 1850 that is broadly consistent with model results. In both data and simulations, large regional variations are superimposed on this common signal, at decadal to centennial timescales. The model results appear spatially more consistent than ice core records. We conclude that more records are needed to resolve the complex spatial distribution of Antarctic temperature variations during the last millennium.