Beschreibung: The Atmosphere Flagship programme addresses various topics, including analyses of long term meteorological observations, the interaction between the surface and the atmospheric boundary layer, the composition of the atmosphere with respect to climate active trace substances like aerosols or green house gases, as well as pollutants, the role of clouds in the Arctic atmosphere, interactions of the atmosphere with the snow covered ground, land-fast and drifting sea ice, surface UV spectral fluxes and its dependency on specific conditions in the stratosphere (ozone) as well as troposphere (clouds). Recently, the role of biogenic aerosols and the observation of black carbon in snow and atmosphere received particular attention. Within the Ny-Aalesund Atmosphere Flagship, we particularly highlight the connections to observations at Barentsburg, Pyramiden, and Hornsund, as well as the pan Svalbard meteorological network.

Beschreibung: The eruptions of the Kasatochi volcano on 7 and 8 August 2008 led to an enhanced stratospheric aerosol load which was studied with the Koldewey Aerosol Raman Lidar (KARL) and the Micro Pulse Lidar (MPL) at the French-German Arctic Research Base AWIPEV in Ny-Ålesund, Spitsbergen at 78.55°N, 11.56°E. During all KARL measurements from 15 August to 24 September 2008 (approximately 30 h of data), we detected distinct layers of enhanced aerosol backscatter in the lower stratosphere and the tropopause region, whose origination at the Kasatochi site can be shown by trajectory calculations. We found a 125% increase in aerosol optical depth compared to the mean values from 2004 to 2007 at 3 weeks after the eruption, validated by sunphotometer measurements. Differences in volume depolarization and color ratio signatures of the layers indicate a sinking movement of the bigger particles to the layer bottom. Furthermore, within higher stratospheric aerosol layers monitored after 25 August 2008, we observed the volume depolarization maximum to be up to 0.8 km below the backscatter maximum. Backscatter and depolarization measurements from 1 September 2008, on which data were collected over 13 h during daylight and darkness, are analyzed in detail. Calculations of the lidar ratio in the lowest aerosol layer as well as the estimation of microphysical parameters of the aerosol particles were performed.

Beschreibung: Svalbard Integrated Arctic Earth Observing System (SIOS) is an international consortium for developing and maintaining a regional observing system in Svalbard and the associated waters. SIOS brings together the existing infrastructure and data from its members into a multidisciplinary network dedicated to answering Earth System Science (ESS) questions related to global change. The Observing System is built around “SIOS Core Data” – long-term data series collected by SIOS partners. SIOS Core Data (SCD) are data that fulfil the following defined criteria: to be relevant for answering key Earth System Science questions (scientific requirements), to be available according to the FAIR principles (data availability), to be secured by members for more than 5 years (member commitment). The first set of SIOS core data variables has been identified by The Science Optimisation Advisory Group (SOAG) in cooperation with the Research Infrastructure Coordination Committee (RICC) and scientific experts. Many (but not all) SIOS core data variables are selected or derived from the Essential Climate Variables (ECVs) defined by The Global Climate Observing System (GCOS), and are described by WMO standards and the Global Change Master Directory (GCMD) Keywords. SIOS core data variables are critical for characterising the climate system and its changes in the Arctic, and answering the ESS science questions outlined in the SIOS Infrastructure Optimization Report. SIOS activities related to SCD are in line with SAON's Roadmap for Arctic Observing and Data Systems process as well as the new EC ArcticPASSION project and the idea of a set of Arctic Shared Variables.