The Illinois State Water Survey’s Health and Environmental Applications Laboratory (HEAL) is the new home of the World Data Centre for Precipitation Chemistry (WDCPC), which receives and archives precipitation chemistry data and complementary information from stations across the globe.

The WDCPC is one of six world data centers in the World Meteorological Organization’s (WMO) Global Atmosphere Watch.

Data provided by WDCPC include measurements of chemicals deposited on Earth’s surface by rainfall, referred to as wet deposition. The major elements of concern include sulfate, nitrate, ammonium, chloride, sodium, potassium, calcium, magnesium, and phosphate, along with pH. Analyzing and distributing regional wet deposition data remains a global environmental necessity to better understand the chemical climatology of the Earth’s atmosphere. This information is vital for scientists, decision makers, and researchers who study acidification, eutrophication, biodiversity, human health, and global climate change.

HEAL will coordinate a supplementary initiative, the Quality Assurance/Science Activity Centre – Americas (QA/SAC-Americas). HEAL serves as the Central Calibration Laboratory for QA/SAC-Americas, which seeks to assess the performance of laboratories and help improve the quality of their wet deposition measurements. QA/SAC-Americas conducts semi-annual laboratory inter-comparison studies to determine if there’s a bias between laboratory measurements, and if so, how to improve future data quality and reliability.

The precipitation chemistry and quality assurance data collected through these two projects will be disseminated to scientists and the public through user-friendly databases and web interfaces.

In October 2019, HEAL director Christopher Lehmann led an international workshop on wet deposition measurements at the Global Atmospheric Watch – Training & Education Centre in Garmish-Partenkirchen, Germany, which included participation from global WMO stations. Participants learned the best methods for wet deposition sample collection, laboratory measurement, quality assurance, and data analysis.

The WDCPC is funded through the National Oceanic and Atmospheric Administration Air Resources Laboratory, and WDCPC maintains close cooperation with a number of regional precipitation monitoring programs and networks.