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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Cosmogenic Be-7 in air: A complex mixture of production and transport

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Author(s):
Leppanen, A. -P. [1] ; Pacini, A. A. [2, 3, 4] ; Usoskin, I. G. [5] ; Aldahan, A. [6, 7] ; Echer, E. [2] ; Evangelista, H. [3] ; Klemola, S. [8] ; Kovaltsov, G. A. [9] ; Mursula, K. [4] ; Possnert, G. [10]
Total Authors: 10
Affiliation:
[1] Radiat & Nucl Safety Author, Reg Lab No Finland, Rovaniemi 96400 - Finland
[2] Natl Inst Space Res INPE, Sao Jose Dos Campos - Brazil
[3] Univ Rio Janeiro State, Rio De Janeiro - Brazil
[4] Univ Oulu, Dept Phys, FIN-90570 Oulu - Finland
[5] Univ Oulu, Sodankyla Geophys Observ, Oulu - Finland
[6] Uppsala Univ, Inst Earth Sci, S-75105 Uppsala - Sweden
[7] United Arab Emirates Univ, Dept Geol, Al Ain - U Arab Emirates
[8] Radiat & Nucl Safety Author, Helsinki - Finland
[9] AF Ioffe Phys Tech Inst, St Petersburg 194021 - Russia
[10] Uppsala Univ, Tandem Lab, S-75105 Uppsala - Sweden
Total Affiliations: 10
Document type: Journal article
Source: JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS; v. 72, n. 13, p. 1036-1043, AUG 2010.
Web of Science Citations: 30
Abstract

The long-time series of (7)Be activity in surface air have been studied with the wavelet analysis technique in order to find coherence between (7)Be activity, theoretical production in the troposphere and climatic indices. The (7)Be activity were obtained from five different locations, Angra in the tropics in Brazil, Skane in mid-latitudes in Southern Sweden, Kiruna in Polar region in Northern Sweden, Loviisa in Southern Finland and Rovaniemi in polar region in Northern Finland. The (7)Be data from the Northern hemisphere sites where tested for coherence with theoretical production of the isotope in troposphere and with the North Atlantic Oscillation index. In the Southern hemisphere separate theoretical production was calculated in order to describe local production and Southern Annular Mode was used as the climatic index. Consistent and significant coherence were found with theoretical production at Skane, Kiruna and Loviisa at time-scales of four years or longer. At Angra and Rovaniemi sites, no coherence was detected between (7)Be theoretical tropospheric production and measured activity at ground level. The coherence between (7)Be data from Skane and Angra and climatic indices is insignificant while data from Northern and Eastern Scandinavia show clear coherence with climatic indices at time-scales of four years or longer. Additionally, significant coherence was found between the cosmic ray induced production and NAO at the time band of 8-12 years whereas the coherence between cosmic ray induced production and SAM was insignificant. This feature implies that the ground level (7)Be activity contain mixed information on both production and transport. This conclusion means that further evaluation through models which enable accurate realistic models that will be investigated in future studies. (C) 2010 Elsevier Ltd. All rights reserved. (AU)