RT journal 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 Águilar, Juan Jesús A1 Moscoso López, José Antonio A1 Urda, Daniel A1 Deka, Lipika A1 Turias Domínguez, Ignacio José A2 Ingeniería Industrial e Ingeniería Civil A2 Ingeniería Informática 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 AB This study aims to produce accurate predictions of the NO2 concentrations at a specific station 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 create the forecasting models. Additionally, a new prediction method was proposed combining LSTMs using a rolling window scheme with a cross-validation procedure for time series (LSTM-CVT). Two different strategies were followed regarding the input variables: using NO2 from the station or employing NO2 and other pollutants data from any station of the network plus meteorological variables. The ANN and LSTM-CVT exogenous models used lagged datasets of different window sizes. Several feature ranking methods were used to select the top lagged variables and include them in the final exogenous datasets. Prediction horizons of t + 1, t + 4 and t + 8 were employed. The exogenous variables inclusion enhanced the model's performance, especially for t + 4 (rho approximate to 0.68 to rho approximate to 0.74) and t + 8 (rho approximate to 0.59 to rho approximate to 0.66). The proposed LSTM-CVT method delivered promising results 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% of the cases. PB MDPI SN 1424-8220 YR 2021 FD 2021-03 LK http://hdl.handle.net/10498/24775 UL http://hdl.handle.net/10498/24775 LA eng DS Repositorio Institucional de la Universidad de Cádiz RD 07-nov-2026