Submicron particle, radon, and soot carbon characteristics over the northeast Atlantic

An accumulation mode (AM) was present in all particle data and was characterized by a lognormal size distribution with parameters N cm^-3 (total number concentration), r_g μm (geometric mean radius) and σ_g (geometric standard deviation). For aerosol associated with the "cleanest' Northeast Atlantic maritime and Arctic air masses, the AM parameters were found to be 16 cm^-3 ≤N≤48 cm^-3, 1.32≤σ_g≤1.46, and 0.08 μm < r_g < 0.09 μm, leading to AM masses of between 0.20 μg m^-3 and 0.38 μg m^-3. Clean background levels of soot carbon mass for maritime and Arctic air were estimated to be around 20 ng m^-3 and were associated with particle size radii r ≤ 0.15 μm. Soot carbon mass showed an excellent correlation with AM number concentration (cc=0.93). By comparison, radon exhibited a significantly poorer correlation (cc=0.60) for this region. -from Authors