Funding for this research was provided by:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (207330/2015-8)
Instituto Nacional de Pesquisas Espaciais (NA)
Text and Data Mining valid from 2020-03-12
Received: 6 December 2019
Accepted: 18 February 2020
First Online: 12 March 2020
: The authors declare that they have no competing interests.