Research Article

Study on the Precursor Signal Capturing of Unfavorable Weather: Months/Years in Advance to Ultra-Early Forecast for Hourly Transient Weather Changes during the Beijing Winter Olympics

Figure 3

Hourly distributions of visibility (VIS) and fog–haze in Beijing for February 1–28, 2017 (a) and (c) 2021; hourly observed distributions of PM2.5, O3, NO2, SO2, the PLAM index, and low-layer atmospheric supersaturation (S) for February 1–28, (b) 2017 and (d) 2021.
(a)
(b)
(c)
(d)