ALBERT

Description: The analysis of the inorganic composition of climatic archives provides proxies for climate reconstruction. For many applications commercially available inductively coupled plasma quadrupole mass spectrometry (ICP-Q-MS) systems are used for investigations. In this talk I will present different application possibilities of the laser ablation (LA)-ICP-Q-MS analysis of different sample matrices.Polar ice cores:Ice from polar regions is an archive of climate. The analysis of element signatures in ice cores yields information about the strength of sources and transport mechanisms for aerosols in the paleoatmosphere as well as about the paleovolcanism. An ice core section from the Holocene, drilled in the Atlantic sector of Antarctica, was analysed by LA-ICP-Q-MS with a spatial resolution of about 4 mm. The analysis of sea salt tracers, mineral dust tracers and tracers for other natural or anthropogenic sources revealed in general enhanced element concentrations during winter months. The ice core included a tephra horizon which source could be identified by the element composition.Bivalves:During the past 10 years, the enhanced input of sediments due to accelerated glaciermelting is observed in Potter Cove at the Antarctic Peninsula. The analysis of the Antarctic soft shell clam Laternula elliptica (Potter Cove, Antarctic Peninsula) by LA-ICP-Q-MS addressed whether the increased sediment input is reflected in the distribution of Fe, and other elements (Al, Mn, Cu, Pb and U) in the ultimate growth bands, which are formed in bivalve umbos. In contrast to our hypothesis, we proved that the accretion of our investigated elements into the umbo matrix is largely a function of animal ecophysiology and life history rather than of climate change.Frozen lake sediment cores:A frozen lake sediment core from Sacrower See (Potsdam Germany), investigated by LA-ICP-Q-MS, showed annual lamination until a depth of 42.7 cm. Our study targeted to settle the question whether the lamination results in varying elemental signature that corresponds to summer and winter layers, with respectively high and low biological activity. The enrichment or depletion of a certain element in a sample relative to the average composition of the Earths crust is expressed as the enrichment factor (EF). From the increased EF of Ca and Sr in the summer layers, we conclude an increased biological activity.

Description: Ship-borne measurements of spectral as well as biologically effective UV irradiance have been performed on the German research vessel Polarstern during the Atlantic transect from Bremerhaven, Germany, to Cape Town, south Africa, from 13 October to 17 November 2005. Such measurements are required to study UV effects on marine organisms. They are also necessary to validate satellite-derived surface UV irradiance. Cloud free radiative transfer calculations support the investigation of this latitudinal dependence. Input parameters, such as total ozone column and aerosol optical depth have been measured on board as well. The maximum daily dose of erythemal irradiance with 5420J/m2 was observed on 14 November 2005, when the ship was in the tropical Atlantic south of the equator. The expected UV maximum should have been observed with the Sun in the zenith during local noon (11 November). Stratiform clouds reduced the dose to 3835 J/m2. In comparison, the daily erythemal doses in the mid-latitudinal Bay of Biscay only reached values between 410 and 980J/m2 depending on cloud conditions. The deviation in daily erythemal dose derived from different instruments is around 5%. The feasibility to perform ship-borne measurements of spectral UV irradiance is demonstrated.