Fig. 1. Thermal maps of 6 kinds of pollutants

Fig. 2. Variation of PM_2.5 concentration at a single station in Shanghai in 2019. (a) One-week variation curve; (b) annual variation curve

Fig. 3. LSTM structure diagram

Fig. 4. Basic network structure of Seq2Seq

Fig. 5. Seq2Seq model fused with attention mechanism

Fig. 6. Flow diagram of the constructed model

Fig. 7. Comparison of PM_2.5 concentration prediction by LSTM, Seq2Seq and Seq2Seq+Attention 3 models in Ningbo site

Fig. 8. Prediction of PM_2.5 concentration in 10 cities of East China in summer based on Seq2Seq+Attention model. (a) Nanjing site; (b) Wuxi site; (c) Suzhou site; (d) Shanghai site; (e) Changzhou site; (f) Nantong site; (g) Zhenjiang site; (h) Hangzhou site; (i) Jiaxing site; (j) Ningbo site

Fig. 9. Prediction of PM_2.5 concentration in 10 cities of East China in winter based on Seq2Seq+Attention model. (a) Nanjing site; (b) Wuxi site; (c) Suzhou site; (d) Shanghai site; (e) Changzhou site; (f) Nantong site; (g) Zhenjiang site; (h) Hangzhou site; (i) Jiaxing site; (j) Ningbo site