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\We present comparisons between estimates of the aerosol optical thickness and the Ångström exponent in Northern Norway and Svalbard based on data from AERONET (Aerosol Robotic Network) stations at Andenes (69.28° N, 16.01° E, 379m altitude) and Hornsund (77.00° N, 15.56° E, 10m altitude) for the period 2008-2011. The four-year annual mean values for the aerosol optical thickness at 500nm °(500) at Andenes and Hornsund both were 0.10. At Hornsund, there was less variation of the monthly mean value of °(500) than at Andenes. The annual mean values of the Ångström exponent ° at Andenes and Hornsund were 1.25 and 1.37, respectively. At Andenes and Hornsund ° was found to be larger than 1.1 in 64% and 86% of the observations, respectively, indicating that fine-mode particles were dominating at both sites. Both sites had a similar seasonal variation of the aerosol size distribution although one site is in an arctic area while the other site is in a sub-arctic area. [ABSTRACT FROM AUTHOR]