Overview of aerosol microphysics at Arctic sunrise: measurements during the NICE renoxification study

Extensive aerosol and trace gas measurements were conducted at Ny-Alesund (Svalbard) before and after Arctic sunrise in 2001 (NICE Dark and Light intensive campaigns) in order to study the possible role of aerosols in the renoxification mechanism. This study reports aerosol physical measurements over a continuous 3- month period. Arctic and sub-Arctic air masses dominated the measurement period and were characterized by low number (N similar to 275 and 590 cm(-3) respectively) and surface area (S similar to 39 and 28 mum(2) cm(-3)) concentrations (measured range d = 14- 740 nm) except for two Arctic haze events with high concentrations in springtime (N similar to 1140 cm(-3) and similar to 125 mum(2) cm(-3)). Excluding these events, aerosol volatility measurements indicated no significant variation in the volatile ( similar to 0.40), semi- volatile (similar to 0.32) or refractory ( similar to 0.28) volume fractions which are commonly attributed to H2SO4, (NH4)(2)SO4 /NH4HSO4 and soot/ dust/ sea- salt aerosol.