Fig. 6From: Variation of major air pollutants in different seasonal conditions in an urban environment in MalaysiaComparison of lower O3 period (2005–2009) and higher O3 period (2010–2015) at S1 station. a Hourly variability; b weekly variability; c monthly variation of bivariate polar annulus plot for lower O3 period and d for higher O3 periodBack to article page