Fig. 5: Gas and aerosol evolution before and after precipitation.
From: Frequent rainfall-induced new particle formation within the canopy in the Amazon rainforest
Composite plot of ATTO trace gas and aerosol data during rain events, using a normalized representation, which shows data from 5 hours before to 5 hours after the rainfall peak for the 2018–2020 wet seasons (February to May). The left axis shows the variation of NO2 at 12 m height, NO at 0.5 m, O3 at 4 m, isoprene at 80 m and monoterpenes at 80 m in units of standard deviations. The right axis shows the variation of nucleation particles (10–40 nm) at 60 m in absolute number concentration. The rain-related concentration changes show increases in O3 and NO2, decreases in NO, isoprene and monoterpenes, and an increase in nucleation particles. All time series incorporate wet-season data (that is, February to May) from 2018 to 2020. Colour-shaded bands represent 95% confidence intervals. The composite was made over 391 rain events with rain rates > 0.5 mm h−1. For NO, NO2 and O3, 114, 94 and 336 rain events, respectively, were used, and for isoprene and monoterpene, 90 rain events were used for the composite.
