Seasonality, Interannual Variability, and Linear Tendency of Wind Speeds in the Northeast Brazil from 1986 to 2011

Abstract

Wind speed analyses are currently being employed in several fields, especially in wind power generation. In this study, we used wind speed data from records of Universal Fuess anemographs at an altitude of 10 m from 47 weather stations of the National Institute of Meteorology (Instituto Nacional de Meteorologia-INMET) from January 1986 to December 2011. The objective of the study was to investigate climatological aspects and wind speed trends. To this end, the following methods were used: filling of missing data, descriptive statistical calculations, boxplots, cluster analysis, and trend analysis using the Mann-Kendall statistical method. The seasonal variability of the average wind speeds of each group presented higher values for winter and spring and lower values in the summer and fall. The groups G1, G2, and G5 showed higher annual averages in the interannual variability of wind speeds. These observed peaks were attributed to the El Niño and La Niña events, which change the behavior of global wind circulation and influence wind speeds over the region. Trend analysis showed more significant negative values for the G3, G4, and G5 groups for all seasons of the year and in the annual average for the period under study.

Surface wind speed: trend and climatology of Brazil from 1980–2014

“…dry and wet bulb temperature, relative humidity, wind speed and direction, cloud coverage and atmospheric pressure) from its manual network of 293 surface weather stations across Brazil. Santos and Silva (2013) describe that wind speed observations gathered from INMET follow and meet the anemometer height standard (10 m) set by the World Meteorological Organization (WMO). However, a setback of using observations from INMET is the lack of continuous periods of record for all given sites.…”

“…Previous work has suggested that wind speeds are slowing across northeastern Brazil (Silva et al, 2010;Pereira et al, 2013;Santos and Silva, 2013). Yet, it has been forecasted that surface winds will increase along coastal and northeastern Brazil based on conditions implemented from IPCC emission schemes and stimulated into general climate models (Lucena et al, 2010;Pereira et al, 2013).…”

“…Much of Brazilian research conducted since Silva et al (2010) has focused on assessing changes in surface winds with respect to present and future wind energy production (Lucena et al, 2010;Pereira et al, 2013;Santos and Silva, 2013;Pes et al, 2017). Lucena et al (2010) showed that future wind energy production should increase for coastal * Correspondence to: J. M. Gilliland, Department of Geography and Anthropology, Louisiana State University, 227 Howe-Russell-Kniffen Geoscience Complex, 70803 Baton Rouge, Louisiana, USA.…”

“…However, their analysis further explored past wind records from 15 Brazilian weather stations and established that the majority (11) of sites is experiencing decreasing or non-significant linear wind speed trends from 1960 to 2007. Santos and Silva (2013) presented a comparable negative wind trend pattern between 1986 and 2011 based upon categorizing 47 northeastern Brazilian stations into five groups by derived using a cluster analysis. The study showed that three of the five groups observed significant (P < 0.01) negative linear trends in seasonal and annual near-surface wind speeds.…”

Assessing Homogeneity and Climate Variability of Temperature and Precipitation Series in the Capitals of North-Eastern Brazil

“…Studies for NEB include the analysis of rainfall characteristics (Rao and Hada, 1990;Rao et al, 2016), trends of (heavy) rainfall events (Oliveira et al, 2012(Oliveira et al, , 2013Priscilla et al, 2014), drought and connected vegetation dynamics (Barbosa et al, 2006(Barbosa et al, , 2015Marengo and Bernasconi, 2015), trends of maximum and minimum temperature (da Silva, 2004), or the tendency of wind speed (Alexandre and Santos e Silva, 2013). Vincent et al (2005) describe changes in the temperature extremes in South America for the period 1961-2000 that are particularly pronounced for climate indices related to minimum temperature, while those based on maximum temperature reveal no consistent changes.…”