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

Extensive aerosol and trace gas measurements were conducted at Ny-Ålesund (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∼ 275 and 590 cm−3 respectively) and surface area (S∼ 39 and 28 μm2 cm−3) concentrations (measured range d= 14–740 nm) except for two Arctic haze events with high concentrations in springtime (N∼ 1140 cm−3 and ∼ 125 μm2 cm−3). Excluding these events, aerosol volatility measurements indicated no significant variation in the volatile (∼0.40), semi-volatile (∼0.32) or refractory (∼0.28) volume fractions which are commonly attributed to H2SO4, (NH4)2SO4/NH4HSO4 and soot/dust/sea-salt aerosol.