Beschreibung: During the ARK XXV 1+2 expedition in the Arctic Ocean carried out in June–July 2010 aboard the R/V Polarstern, we measured carbon monoxide (CO), non-methane hydrocarbons (NMHC) and phytoplankton pigments at the sea surface and down to a depth 5 of 100m. The CO and NMHC sea-surface concentrations were highly variable; CO, propene and isoprene levels ranged from 0.6 to 17.5 nmol l−1, 1 to 322 pmol l−1 and 1 to 541 pmol l−1, respectively. The CO and alkene concentrations were enhanced in polar waters off of Greenland, which were more stratified because of ice melting and richer in chromophoric dissolved organic matter (CDOM) than typical North Atlantic 10 waters. The spatial distribution of the surface concentrations of CO was consistent with our current understanding of CO-induced UV photo-production in the sea. The vertical distributions of the CO and alkenes followed the trend of light penetration, with the concentrations displaying a relatively regular exponential decrease down to nonmeasurable values below 50 m. However, no diurnal variations of CO or alkene con15 centrations were observed in the stratified and irradiated surface layers. This finding suggests that the production and removal processes of CO and alkenes were tightly coupled. We tentatively determined a first-order rate constant for the microbial consumption of CO of 0.5 d−1, which is in agreement with previous studies. On several occasions, we observed the existence of subsurface CO maxima at the level of the 20 deep chlorophyll maximum. This finding represents field evidence for the existence of a non-photochemical CO production pathway, most likely of phytoplanktonic origin. The corresponding production rates normalized to the chlorophyll content were in the range of those estimated from laboratory experiments. In general, the vertical distributions of isoprene followed that of the phytoplankton biomass. Hence, oceanic data support the 25 existence of biological production of CO and isoprene in the Arctic Ocean

Beschreibung: The 10th TRACE conference (Tree Rings in Archaeology, Climatology and Ecology) was organized by the Institut National de la Recherche Agronomique (INRA) - Centre d'Orléans Unité Amélioration, Génétique et Physiologie Forestières, on May 11th – 14th 2011 in the “Muséum des Sciences Naturelles” in Orléans, France. [...] This volume of TRACE Proceedings contains 16 short papers and gives an overview of the wide spectrum of fields in tree-ring research.

Beschreibung: INTERACT (International Network for Terrestrial Research and Monitoring in the Arctic): The INTERACT network is a one-stop shop for access to research infrastructures in the Arctic and mountain areas of the Northern Hemisphere. The main objective of the INTERACT network is to build capacity for identifying, understanding, predicting and responding to changes throughout the wide environmental and land-use envelopes of the Arctic and mountain areas of the Northern Hemisphere. The INTERACT network of field stations provides a unique platform for terrestrial sciences and the network hosts and operates top level research and monitoring projects and programmes within a wide range of scientific disciplines. In this catalogue you will find details of all the INTERACT stations that can be used for selecting research infrastructures that suit your specific scientific needs. It is our hope that you will find this catalogue useful in the planning of your scientific activities or simply enjoy an interesting tour of a variety of terrestrial field basis in the INTERACT network.