Temporal dynamics and forecasting of aerosol optical depth in megacities Lahore and Karachi: Insights from the Indo-Gangetic Basin and southern Pakistan, and implications for Sustainable development

Abstract

This scientific study investigates the temporal dynamics and forecasts aerosol optical depth (AOD) in Lahore and Karachi, Pakistan's two most populated cities. Lahore, in the center of the Indo-Gangetic Basin, and Karachi, on the southern coast, have issues from growing urbanization and significant aerosol emissions. Understanding AOD trends is critical for successful environmental management, public health planning, and climate change mitigation. Using the Box-Jenkins ARIMA models, this work systematically analyses monthly AOD fluctuations from July 2002 to May 2023 to confirm their predicting accuracy. The autocorrelation function (ACF) and partial autocorrelation function (PACF) have been employed to estimate the suitable model and identify significant lags to maintain prediction accuracy. The study concludes with a judgment that Model A is ideal for the ecology of Karachi and Model B for the ecology of Lahore. The forecast till January 2030 is available to look at several trends on AOD, namely, periods of seasonal solid fluctuations for both sites. This diversity emphasizes the need for specific actions, such as stricter environmental regulations, air quality monitoring, and providing greener transport solutions, which will result in blue skies. Utilizing the in-depth observations and forecast of the changing distribution of AOD values, the study helps develop approaches for reducing aerosol pollution. This is also one of the key contributions. We investigated critical environmental problems in the cities of Karachi and Lahore and provided means for such issues' resolution, enabling sustainable development and clean air.