NETCARE: Observations of New Particle Formation and Growth in the Arctic Summertime

NETCARE (Network on Climate and Aerosols: Addressing Fundamental Uncertainties in Remote Canadian Environments) is a Canadian research network established four years ago. This talk will present an overview of the network, which has had research projects involving ground-, ship- and aircraft-based observations, alongside GCM and CTM modeling efforts. This talk will address in particular results from summertime observations when the open ocean becomes a more dominant element of the regional biogeochemical system. In particular, observation from the Canadian Arctic indicate that substantial new particle formation and growth occur in marine boundary layer environments, with impacts on both the number and chemical nature of particles that act as cloud condensation nuclei. Most of the growth of these particles is via condensation of organic mass. The detailed input of molecules from the oceans however, in particular with respect to the organic species that allow particles to grow to CCN sizes, is uncertain. Correlations of gas-phase semi-volatile organic molecules with the dissolved organic content of ocean water suggest the source of the organic mass is marine. The overall motivation for studies of the Arctic atmosphere in the clean summertime is to better understand the nature of biogeochemical processes that will become more prevalent as summer sea ice retreats.