RT info:eu-repo/semantics/article T1 Artificial Neural Networks, Sequence-to-Sequence LSTMs, and Exogenous Variables as Analytical Tools for NO2 (Air Pollution) Forecasting: A Case Study in the Bay of Algeciras (Spain) A1 González Enrique, Francisco Javier A1 Ruiz Aguilar, Juan Jesús A1 Moscoso López, José Antonio A1 Urda Muñoz, Daniel A1 Deka, Lipika A1 Turias Domínguez, Ignacio J. K1 Forecasting K1 Feature selection K1 Air pollution K1 Nitrogen dioxide K1 Artificial neural networks K1 LSTMs K1 Exogenous variables K1 Deep learning K1 Time series K1 Informática K1 Computer science AB This study aims to produce accurate predictions of the NO2 concentrations at a specificstation of a monitoring network located in the Bay of Algeciras (Spain). Artificial neural networks(ANNs) and sequence-to-sequence long short-term memory networks (LSTMs) were used to createthe forecasting models. Additionally, a new prediction method was proposed combining LSTMsusing a rolling window scheme with a cross-validation procedure for time series (LSTM-CVT). Twodifferent strategies were followed regarding the input variables: using NO2from the station oremploying NO2 and other pollutants data from any station of the network plus meteorologicalvariables. The ANN and LSTM-CVT exogenous models used lagged datasets of different windowsizes. Several feature ranking methods were used to select the top lagged variables and include themin the final exogenous datasets. Prediction horizons of t + 1, t + 4 and t + 8 were employed. Theexogenous variables inclusion enhanced the model’s performance, especially for t + 4 (ρ ≈ 0.68 toρ ≈ 0.74) and t + 8 (ρ ≈ 0.59 to ρ ≈ 0.66). The proposed LSTM-CVT method delivered promisingresults as the best performing models per prediction horizon employed this new methodology.Additionally, per each parameter combination, it obtained lower error values than ANNs in 85% ofthe cases. PB MDPI YR 2021 FD 2021-03 LK http://hdl.handle.net/10259/7233 UL http://hdl.handle.net/10259/7233 LA eng NO This research was funded by MICINN (Ministerio de Ciencia e Innovación-Spain), grant number RTI2018-098160-B-I00, and grant “Ayuda para Estancias en Centros de Investigación del Programa de Fomento e Impulso de la actividad Investigadora de la Universidad de Cádiz”. DS Repositorio Institucional de la Universidad de Burgos RD 02-may-2024