Development of an Open-Source Harmonized Low-Cost Sensor Data Archive to Maximize Scientific Return from Existing Networks

We reviewed 60 sensor networks and 17 related efforts (sensor review papers and data accessibility projects) to better understand the landscape of stationary low-cost gas-phase sensor networks deployed in outdoor environments worldwide. We found that particulate matter (PM) is more commonly studied globally than gas-phase compounds, and coverage gaps are most severe in the Global South and rural areas. Data quality and availability were also found to be barriers to access, with the highest quality data typically emanating from research institutions, which also tend to have the least straightforward data access for the public. In response, we aim to harmonize sensor networks by amalgamating measurements from a multitude of networks into one open access database hosted by NASA’s Atmospheric Science Data Center. As of early 2025, data from 12 unique US-based sensor networks have been collected for redistribution in the archive, and we are currently recruiting global network participants. Data from each network will be reformatted in a common data format with metadata embedded to streamline data processing. A key feature is a tier system in which we critically review each sensor network by their calibration efforts and subsequent data quality, providing data quality flags to help end users determine which sensor data best meets their target application. The accessible and inclusive open science platform will allow users to search based on calibration criteria in addition to location, date range, and pollutant of interest. The sensor database is aimed at scientific end users seeking ground-based validation data for satellites and models alike, but is also accessible to community scientists. Future iterations will include data from global sensor networks, and assimilation with satellite and ground-based remote sensing data.