Atmospheric 222Rn concentration and source term at El Arenosillo 100 m meteorological tower in southwest Spain

Rn-222 concentration time series at 10 m and at 100 m have been measured hourly for one year at the meteorological station, El Arenosillo, on the Spanish southwest coast. A Rn-222 flux characterization was also done. A seasonal analysis of atmospheric Rn-222 concentration was performed and results for each season present evidence associated with the origin of air masses reaching the El Arenosillo station. An increase in 2(222)Rn concentration was observed when the wind came from Morocco, the Sierra Morena and the Guadalquivir valley areas. On the other hand, a net Rn-222 concentration decrease was found when the wind came from the Atlantic Ocean and the South of Portugal. Low Rn-222 flux of 4 Bq M-2 h(-1) was measured. This result makes this station a useful site for studies related to remote Rn-222 source contributions because of low local Rn-222 background. The measured annual average concentration of Rn-222 gas at the El Arenosillo station is 3.51 +/- 0.05 Bq m(-3) at 10 m and 2.61 +/- 0.05 Bq m(-3) at 100 m. (C) 2011 Elsevier Ltd. All rights reserved.