文摘
Air pollution has been an internationally growing concern. Modeling and forecasting daily movement of ambient air mean NO2 concentration is an increasingly important task for its adverse effects on human health. With weekly quasi-periodic extension for daily movement of mean NO2 concentration, the elliptic orbit model is introduced to depict its movement. Daily movement of mean NO2 concentration as a time-series is mapped into the polar coordinates to build the elliptic orbit model, in which each 7-day-movement is described as one elliptic orbit. Experiments and result analysis indicate workability and effectiveness of the proposed method. It is shown that with weekly quasi-periodic extension, daily movements of mean NO2 concentration at the given monitoring stations in China are well described by the elliptic orbit model, which presents a vivid description for analyzing daily movement of mean NO2 concentration in a concise and intuitive way.