Ambient Particulate Matter (PM2.5) and Relative Humidity Time Series from a Low-Cost Sensor Deployment in Limassol, Cyprus.

These two datasets contain particulate matter (≤2.5µm) (PM2.5) and relative humidity measurements from two co-located low-cost sensor systems deployed on the rooftop of the Cyprus University of Technology (CUT) in Limassol, Cyprus. The measurements were collected between 15 November 2023 and 21 December 2023. The two sensor units were operated with different temporal resolutions. Sensorset_1 provides measurements at one-minute intervals, while sensorset_2 records data at 10-second intervals (from 26 November 2023 onward). The data were used to investigate oscillations in PM2.5 concentrations on timescales of a few minutes and to identify signatures of near-surface atmospheric gravity waves. The raw PM2.5 measurements were corrected using a reference air quality station (operated by the Cypriot Department of Labour Inspection, Air Quality Section) through a linear regression approach that incorporates both PM2.5 and relative humidity. The dataset therefore includes humidity-adjusted PM2.5 values. Data are provided in CSV format (comma-separated). rpi_time_utc: Timestamp (UTC) in the format YYYY-MM-DD HH:MM:SS. pm25: Raw PM2.5 concentration [µg m-3] pm25_corrected: Humidity_corrected PM2.5 concentration [µg m-3] humidity_rH: Relative humidity [%] The measurements were obtained using Plantower PMSA003I PM sensors and TE Connectivity MS8607 relative humidity sensors integrated into custom-built low-cost sensor systems.