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

We present ARPALData, an R package able to help international users in retrieving, handling, and analyzing data for air quality and weather in Lombardy (Northern Italy). The software provides a user-friendly tool that does not require access to institutional platforms and ensures real-time updating of information using a standardized syntax. Also, it provides data according to the standard statistical formats. Eventually, all measurements, metadata and the subsequent analytical tools are provided to the users in the English language, facilitating accessibility to international and domestic users. Data are collected from the open database of the Regional Agency for Environmental Protection for Lombardy, namely ARPA Lombardia. ARPALData returns measurements at several temporal frequencies (infra-hourly to yearly) collected through the 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 the data download functions, ARPALData includes several functions to describe, analyze, and graphically represent air quality and weather data. In particular, users are provided with commands to compute key descriptive statistics and maps of input data, to temporally aggregate measurements, to detect outliers, and to study missing value patterns. After discussing the purpose and the functioning of the main commands in detail, the paper presents several 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 of accomplished analyses using all the tools included in ARPALData.