Description: The precipitation conditions in central Karakoram are investigated on the basis of snow samples from high elevated snow pits at Urdok glacier from 2006 and the analysis of atmospheric transport trajectories in combination with the general, large scale pressure distribution. Our analysis shows that accumulation at the high elevated regions of the central Karakoram is dominated by the west wind circulation (WWC). Incursions of the South Asian monsoon (SAM) occur sometimes during the summer months accompanied by strong precipitation but play a minor role for the total accumulation amount. Dust layers found in the snow pits show a rare earth elements signature which indicates that the dust very likely originates from the arid regions of western China and Central Asia. Our trajectory calculations based on NCEP/NCAR reanalysis data confirm that especially during late spring and early summer the westerly flow is redirected over the Tarim basin to reach central Karakoram from an East/Southeast direction. The preservation of the layer structure and the clear seasonal signals in the snow pits indicate that locations above 5200 m in central Karakoram will be suitable places for retrieving longer climate records from ice cores.

Description: Since the 1960-s the stable water isotope signal in ice core records has been used as a proxy for palaeotemperatures. However, this direct interpretation of the isotope signal has limitations, as the relationship between the isotope ratio and atmospheric temperature is known to fluctuate both spatially and temporally. One way to circumvent these limitations is the use of diffusion thermometry as pioneered by Johnsen et al (2000). In the firn stage the isotope signal is subject to a smoothing caused by the random movement of water vapour in the pores of the snow. The total amount of diffusion a layer has suffered is measured in terms of the diffusion length. This length is sensitive to changes in firn temperature and the accumulation rate at the site. The diffusion length for Oxygen-18 is higher than that for Deuterium due to a difference in ice-vapour fractionation factors. As these fractionation factors are dependent on the temperature of the firn, the difference in diffusion length can be used to estimate past local temperatures. To apply this differential diffusion method successfully, it is necessary to have high resolution measurements for both Oxygen-18 and Deuterium. We present such measurements for the EDML ice core. In total 400 m of ice was measured with a 5 cm resolution from periods in the mid and early Holocene, the last glacial-interglacial transition and the last glacial period. Application of the differential diffusion method to this dataset shows a decreasing temperature trend during the Holocene and a surface temperature of approximately -55 °C in the interval representing the LGM in the ice (~10 °C colder than present day temperature (not corrected for changes in altitude)). This is, within the error limits, in line with the temperature reconstructed from the stable water isotope proxy itself using the spatial isotope/temperature gradient (EPICA community members, 2006). References: Johnsen, S. et al, 2000. Diffusion of stable isotopes in polar firn and ice: the isotope effect in diffusion. In: Physics of Ice Core Records, Ed: Hondoh, T., p.121-140, Hokkaido Press, Sapporo. EPICA community members, 2006. One-to-one coupling of glacial climate variability in Greenland and Antarctica. Nature 444, p.195-198.

Description: Using high resolution chemical impurity and dielectric profiling data annual layers have been counted on the EPICA ice core from Dronning Maud Land (EDML), Antarctica spanning the past 16700 years. The methodology used for counting Greenland ice cores and creating the Greenland Ice Core Chronology 2005 (GICC05) [Rasmussen et al., 2006] has also been implemented for the EDML counting. The estimated maximum counting error for the EDML counting is approx. 5%, but a preliminary volcanic matching with Greenland ice core records suggest differences of 1% or less during the Holocene between the EDML counting and GICC05. A comparison of cosmogenic isotope records from EDML and Greenland also suggests differences of less than 1% between the two annual layer counted chronologies. Reference: Rasmussen, S.O., Andersen, K.K., Svensson, A., Steffensen, J.P., Vinther, B.M., Clausen, H.B., Andersen, M.L.S., Johnsen, S.J., Larsen, L.B., Dahl-Jensen, D., Bigler, M., Röthlisberger R., Fischer H., Goto-Azuma K., Hansson M.E., Ruth U, A new Greenland ice core chronology for the last glacial termination, Journal of Geophysical Research Vol. 111, D06102, doi:10.1029/2005JD006079. 2006.

Description: The Vernagtferner region has a long tradition of glaciological research performed by groups from Munich. It started in 1889, when Prof. Sebastian Finsterwalder from the Technical University in Munich produced the first map of a complete glacier based on terrestrial photogrammetry. Since then, numerous maps of the glacier have been made, describing the change in surface elevation for more than a century. These maps form the basis of the geodetic method of glacier mass balance determination, which provides volume changes as average data for the period between two surveys, i.e. typically for 10 years. Since the start of the glaciological method on Vernagtferner in 1964, annual as well as winter and summer mass balance data are available continuously. But only since 1973, the construction of the Vernagtbach station, approximately 1 km below the glacier margin at that time, provided the means to record a larger number of hydrological and meteorological parameters with a temporal resolution of typically 1 hour.

Description: From 1974 to 1982 repeated tracer tests using fluorescent dyes were carried out in the highly glaciated drainage basin of Vernagtbach. These tests enabled the quantitative determination of the runoff in the forefield of the Vernagtferner, the calculation of travel times of the stream water and estimations of the relative contributions to the entire runoff originating from individual streams. In addition, tracer tests were carried out in the firn area of the glacier resulting in data concerning the storage and travel time of meltwater inside the glacier.

Description: During an extensive field program, glaciologcal data have been collected at Nioghalvfjerdsfjiorden Glacier (79 North Glacier) in NE-Greenland in 1997 and 1998. A central part of the field work was dedicated to seismic investigations of the floating part of the glacier, determining the ice thickness, the underlying water column depth and the bedrock elevation. The seismic reflexion measurements were carried out with a 24-channel seismograph (Strataview). 600g explosives were used as energy source at a distance of 100 m from the first geophone. Details about the measurements and the project can be found in Mayer et al. (2000).

Description: During an extensive field program, glaciologcal data have been collected at Nioghalvfjerdsfjiorden Glacier (79 North Glacier) in NE-Greenland in 1997 and 1998. A central part of the field work was dedicated to seismic investigations of the floating part of the glacier, determining the ice thickness, the underlying water column depth and the bedrock elevation. The seismic reflexion measurements were carried out with a 24-channel seismograph (Strataview). 600g explosives were used as energy source at a distance of 100 m from the first geophone. Details about the measurements and the project can be found in Mayer et al. (2000).