Size-segregated aerosol measurements were made in Ny Ålesund, Svalbard, as a part of an EU funded project NICE, (NItrogen Cycle and Effects on the oxidation of atmospheric trace species at high latitudes). The measurements were made during two field campaigns: the dark campaign that took place during the Polar night and the light campaign that took place after the Polar sunrise in winter/spring 2001. Three particle types (sulfate, sea-salt, and crustal particles) could be identified and their concentrations varied independently of each other during the measurements. Non-sea-salt sulfate (nss-SO42) was the most abundant ion during the campaigns, and its rather high concentrations indicates that long-range transport was an important source of the sulfate aerosol at the measurement site. The concentration of ammonium followed typically that of nss-SO42, but was much lower, making the bulk aerosol quite acidic. Methanesulfonate could be detected during the light campaign only, which suggests that the contribution of biogenic sulfur to the observed SO42 was neglible during the dark campaign and small but notable (average <15%) during the light campaign. Nss-SO42, ammonium and methanesulfonate were found predominantly in the submicron size range and their similar modal structures indicate that they were internally mixed. Sodium and chloride were the most abundant ions after sulfate, which demonstrates the important role of sea-salt particles to the overall aerosol mass during the measurements. The concentrations of crustal tracers, non-sea-salt calcium and non-sea-salt magnesium, behaved differently during the campaigns, which is probably due to the presence of two different crustal sources affecting the measurement site. The concentration of nitrate was relatively low during both campaigns, being typically less than one tenth of the respective nss-SO42 concentration. The acidic nature of submicron particles explains also why little nitrate was found in the submicron size range. During the dark campaing most of the nitrate was bound to sea-salt particles, whereas during the light campaign it was also bound to crustal particles.
Aerosol chemistry during the NICE dark and light campaigns
H J Beine
2003
Abstract
Size-segregated aerosol measurements were made in Ny Ålesund, Svalbard, as a part of an EU funded project NICE, (NItrogen Cycle and Effects on the oxidation of atmospheric trace species at high latitudes). The measurements were made during two field campaigns: the dark campaign that took place during the Polar night and the light campaign that took place after the Polar sunrise in winter/spring 2001. Three particle types (sulfate, sea-salt, and crustal particles) could be identified and their concentrations varied independently of each other during the measurements. Non-sea-salt sulfate (nss-SO42) was the most abundant ion during the campaigns, and its rather high concentrations indicates that long-range transport was an important source of the sulfate aerosol at the measurement site. The concentration of ammonium followed typically that of nss-SO42, but was much lower, making the bulk aerosol quite acidic. Methanesulfonate could be detected during the light campaign only, which suggests that the contribution of biogenic sulfur to the observed SO42 was neglible during the dark campaign and small but notable (average <15%) during the light campaign. Nss-SO42, ammonium and methanesulfonate were found predominantly in the submicron size range and their similar modal structures indicate that they were internally mixed. Sodium and chloride were the most abundant ions after sulfate, which demonstrates the important role of sea-salt particles to the overall aerosol mass during the measurements. The concentrations of crustal tracers, non-sea-salt calcium and non-sea-salt magnesium, behaved differently during the campaigns, which is probably due to the presence of two different crustal sources affecting the measurement site. The concentration of nitrate was relatively low during both campaigns, being typically less than one tenth of the respective nss-SO42 concentration. The acidic nature of submicron particles explains also why little nitrate was found in the submicron size range. During the dark campaing most of the nitrate was bound to sea-salt particles, whereas during the light campaign it was also bound to crustal particles.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
