Aerosol particle elemental size distributions during the Arctic Oceanexpedition in the summer of 2001

The central arctic ocean is a region that is particularly sensitive to changes in climate due to various feedbackmechanisms that exist there. during the arctic summer, aerosol particles influence the radiative balance primarilyby acting a cloud condensation nuclei, knowledge of the sources and properties of these particles being essentialfor an adequate assessment of future climate changes in the arctic region. as part of an atmospheric researchprogramme, aerosol samples were collected on filters (sfu: stacked filter unit) and cascade impactors (an lpi:a dekati low-pressure impactor; and an sol: a small deposit impactor) during an expedition to the arcticocean in the summer of 200) on the swedish icebreaker oden. the aerosol samples were analyzed by pixe(particle induced x-ray emission) to obtain information concerning their size-resolved elemental composition.the elements si, s, ci, k, ca, ti, fe, zn and br were usually found in concentrations above their detection limits,also within the pack ice between 88°-89° n. the sources of these elements at these high latitudes could beattributed to sea spray production (ci, k, ca, s, br), secondary oms-derived sulphur compounds (s), and asource of primary aerosol particles that contributed to the concentrations of the elements si, k, ca, ti, fe andzn. this latter source has a composition which resembles that of average crustal rock. a likely transport route ofminerals to the high arctic is by way of ice-rafting by means of the transpolar current. these minerals originatefrom siberian river runoff into the laptev and kara seas. on the basis of the data available, the possibility cannotbe ruled out that the minerals were first processed by the arctic ocean biota before becoming airborne.it appears that bubble bursting tat ejects solid particles from the sea surface micro layer or the sea water belowinto the atmosphere, a process that only take place in the open leads between ice floes, is a major source of primaryaerosol particles, which are composed of sea salt and of crustal or biogenic matter. the ice-rafting ofcrustal material by way of the transpolar current and the bubble bursting that occurs in open leads are both potentiallysensitive to changes in climate.