Modeling and forecasting daily movement of ambient air mean PM_(2.5) concentration based on the elliptic orbit model with weekly quasi-periodic extension: a case study

摘要

Nowadays, the issue of air pollution has continuously been a global public health concern. Modeling and forecasting daily movement of ambient air mean PM_(2.5) concentration is an increasingly important task as it is intimately associated with human health that the air pollution has unig-norable negative effects in reducing air quality, damaging .-nvironment, even causing serious harm to health. It is demonstrated that daily movement of mean PM_(2.5) concentration approximately exhibits weekly cyclical variations as daily particle pollution in the air is largely influenced by human daily activities. Then, based on weekly quasi-periodic extension for daily movement of mean PM_(2.5) concentration, the ciilled elliptic orbit model is proposed to describe its movement. By mapping daily movement of mean PM2.5 concentration as one time series into the polar coordinates, each 7-day movement is depicted as one elliptic orbit. Experimental result ;md analysis indicate workability and effectiveness of the proposed method. Here we show that with the weekly quasi-puriodic extension, daily movements of mean PM2.5 concen-1 ration at the given monitoring stations in Xiangtan of China die well described by the elliptic orbit model, which provides a vivid description for modeling and prediction daily movement of mean PM2,s concentration in a concise and intuitive way.