ARPALData: an R package for retrieving and analyzing air quality and weather data from ARPA Lombardia (Italy)

We present ARPALData, an R package that can help international users retrieve, handle, and analyze air quality and weather data in the Lombardy region (Northern Italy). The software provides a user-friendly tool that directly inquires into the platform of the regional environmental protection agency and ensures real-time updating of information using standardized syntax. The software provides data in standard statistical formats. Eventually, all measurements, metadata, and subsequent analytical tools are provided to users in English, facilitating accessibility to international and domestic users. Data are collected from the open database of the Regional Agency for Environmental Protection of Lombardy, namely ARPA Lombardia. ARPALData returns measurements at several temporal frequencies (infra-hourly to yearly) collected through air quality and weather ground monitoring networks managed by ARPA Lombardia, as well as estimates of several pollutants at the municipal level. In addition to data download functions, ARPALData provides functions to explore, describe, analyze, and graphically represent air quality and weather data. In particular, users are provided with functions to compute key descriptive statistics and input data maps, temporally aggregate measurements, detect outliers, and study missing-value (gap length) patterns. Herein, we discuss purposes, goals, and functioning of the package, and present three guided examples and case studies in which the software is used to characterize air quality and meteorology in different settings. The examples are designed to provide a step-by-step guide for accomplished analyses using the most relevant tools included in ARPALData.