Training in sources, sinks and impacts of atmospheric nitrogen deposition in the Arctic - Tjarda Roberts

The NSINK Initial Stage Network training network targets one of the most vital, interdisciplinary problems facing future Arctic environmental management: namely the enrichment of Arctic terrestrial and aquatic ecosystems by reactive atmospheric nitrogen f rom low latitude emission centers. The problem is tackled through 6 different WP: WP I Atmospheric processes and Inputs (Norwegian Polar Institute). -Analysis of air quality and climatology at Ny-Alesund. Examination of air -Examination of air to snow interactions during winter and spring -Construction of models of reactive nitrogen transport to Ny-Alesund WP II Ice core and Firn chemistry (Uppsala University). -Retrieving new ice cores from high elevation Svalbard core sites -Construct phys ical and chemical analysis of the ice cores -Documentation of recent environmental change, nitrogen enrichment and the capacity for ice cores to determinate between the various types of atmospheric loading events WP III Hydrologic transfers (Sheffield Un iversity). -Integration of atmospheric, terrestrial and aquatic nitrogen reservoirs - Aqueous nitrogen mass balance WP IV Terrestrial ecosystems (Sheffield University). -Impact on plant community structures and function of enhanced N deposition -Microbiological processes within the soil WP V Aquatic Ecosystems and Palaeolimnology Aquatic Ecosystems and Palaeolimnology (Innsbruck University). -Microbial food-webs and nitrogen cycling in the aquatic ecosystems - Palaeolimnology of local lakes in Svalbard including the history and drivers of physico-chemical conditions throughout the late Holocene by examining lake sediments WP VI Integrative Modelling (Centre for Ecology and Hydrology). Use of natural isotope abundance as tracers of r eactive nitrogen throughout the entire system - Mass balance models using 15N-NO3, 18O-NO3 and 15N- NH4 and other natural isotopes