Transport mechanisms and photochemical degradation of persistent pollutants in the Arctic cryosphere

It is proposed to collect field data during the summer of 2005 at the Greenland Environmental Observatory at Summit (GEOSummit). Collection of field data will focus on determining the recent profile of persistent compounds in the snowpack and intercompari ng that data with atmospheric measurements toward developing a ?transfer function? for the reversibly deposited species of interest. In addition, rapid photochemical cycling will be investigated in situ as the samples are collected and analyzed. This work has been successfully completed previously to investigate nitrogen photochemistry in the snowpack. The proposed work expands on that methodology, and will be conducted in collaboration with current research investigating the sources and photochemical tra nsformations of organic matter incorporated into the snow at Summit. A primary objective of the fieldwork will be to develop a temporal history of persistent pollutant deposition for intercomparison with modelled transport data through the collection of d eep snow pits and shallow firn cores. Existing at Summit is an array of stakes with absolute depth-age markers for the development of a high-resolution depth-age scale of snow pits and shallow firn cores. Modelling and laboratory studies will be conducte d with Andreas Stohl and Roland Kallenborn of the Norwegian Institute for Air Research (NILU) following the first season of field data collection. Atmospheric modelling will focus on understanding the relationship between transport processes, climate dyna mics, and deposition. There is recent evidence that quasi-predictable atmospheric processes, such as the North Atlantic Oscillation (NAO), drive pollutant transport. Utilizing high temporal resolution pollutant deposition records and comparing these data with transport models we aim to better understand factors controlling transport of pollution to the Arctic with the goal of enhancing predictive capabilities of pollutant transport pathways.