High elevation, thin ozone layer, and clear sky produce intense ultraviolet (UV) radiation in the tropical Andes. Recent models suggest that tropical stratospheric ozone will slightly decrease in the coming decades, potentially resulting in more UV anomalies. Data collected between 4300 and 5916 m above sea level (asl) in Bolivia show how this trend could dramatically impact surface solar irradiance. During 61 days, two Eldonet dosimeters recorded extreme UV-B irradiance equivalent to a UV index (UVI) of 43.3, which is the highest ground value ever reported. If they become more common, events of this magnitude may have societal and ecological implications, which make understanding the process leading to their generation critical. Our data show that this event and other major UV spikes were consistent with rising UV-B/UV-A ratios in the days to hours preceding the spikes, trajectories of negative ozone anomalies (NOAs), and radiative transfer modeling.
Keywords: record solar UV irradiance, negative ozone anomaly, UV index
Citation: Cabrol NA, Feister U, Häder D-P, Piazena H, Grin EA and Klein A (2014) Record solar UV irradiance in the tropical Andes. Front. Environ. Sci. 2:19. doi: 10.3389/fenvs.2014.00019
Received: 18 April 2014; Accepted: 19 May 2014;
Published online: 08 July 2014.
Edited by:Peter Rolf Richter, Friedrich-Alexander-University, Germany
Reviewed by:Rajeshwar P. Sinha, Banaras Hindu University, India
Copyright © 2014 Cabrol, Feister, Häder, Piazena, Grin and Klein. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Nathalie A. Cabrol, Space Science Division, The SETI Institute Carl Sagan Center/NASA Ames, MS 245-3, Moffett Field, CA 94035-0001, USA e-mail: firstname.lastname@example.org