Trends in solar radiation in NCEP/NCAR database and measurements in northeastern Brazil Academic Article uri icon


  • The database from the National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) re-analysis project available for the period from 1948 to 2009 was used for obtaining long-term solar radiation for northeastern Brazil. Measurements of global solar radiation (R s ) from data collection platform (DCP) for four climatic zones of northeastern Brazil were compared to the re-analysis data. Applying cluster analysis to R s from database, homogeneous sub-regions in northeastern Brazil were determined. Long times series of R s and sunshine duration measurements data for two sites, Petrolina (09°09'S, 40°22'W) and Juazeiro (09°24'S, 40°26'W), exceeding 30. years, were analyzed. In order to exclude the decadal variations which are linked to the Pacific Decadal Oscillation, high-frequency cycles in the solar radiation and sunshine duration time series were eliminated by using a 14-year moving average, and the Mann-Kendall test was employed to assess the long-term variability of re-analysis and measured solar radiation. This study provides an overview of the decrease in solar radiation in a large area, which can be attributed to the global dimming effect. The global solar radiation obtained from the NCEP/NCAR re-analysis data overestimate that obtained from DCP measurements by 1.6% to 18.6%. Results show that there is a notable symmetry between R s from the re-analysis data and sunshine duration measurements. © 2010 Elsevier Ltd.

altmetric score

  • 1

author list (cited authors)

  • Silva, V., Silva, R., Cavalcanti, E. P., Braga, C. C., Azevedo, P., Singh, V. P., & Pereira, E.

citation count

  • 26

complete list of authors

  • Silva, Vicente de Paulo Rodrigues da||Silva, Roberta Araújo E||Cavalcanti, Enilson Palmeira||Braga, Célia Campos||Azevedo, Pedro Vieira de||Singh, Vijay P||Pereira, Emerson Ricardo Rodrigues

publication date

  • October 2010