The Atmospheric Mercury Network (AMNet) established this network of monitoring stations for the purpose of measuring atmospheric mercury fractions which contribute to dry and total mercury deposition. Sites will collect concentrations of atmospheric mercury species from automated, continuous measuring systems, concentrations of total mercury in precipitation, and meteorological measurements. Data will be collected with standardized methods, with quality assured data archived in an online data base.
Note: In May 2025, the Executive Committee approved the motion to discontinue support of Tekran speciation measurements by the end of current site contracts, at the discretion of the Program Office (PO). The PO will provide sites that want to continue speciation measurements with the data validation program for the GOM/PBM measurements.
AMNet has specific objectives:
- Measure atmospheric mercury concentrations of elemental mercury in select locations
- Offer high-quality measurement data to estimate dry and total deposition of atmospheric mercury to other researchers
- Standardized operational methods so that instruments are being operated consistently
- Provide internal and external quality assurance
- Provide the data management capability and access
- Provide field support through an experienced site liaison
As with other networks, NADP welcomes the participation of other organizations and scientists. To truly understand the mercury problem, more monitoring information is needed.
Information on joining the network is available here.
Data Notices
Notification: The Program Office is alerting data users that the Gaseous Oxidized Mercury (GOM) and Particulate-bound Mercury (PBM) measurements were discontinued in 2025 and that the data provided on the website include a known bias in GOM/PBM.
Metadata
Field Methods
Monitoring and analysis of elemental, gaseous oxidized and particulate Mercury fractions use a 2.5-micrometer impactor and KCl-coated annular denuder (for ionic mercury), thermally-desorbed particulate filter (for particulate-bound mercury), and gold traps (for elemental mercury). Analysis uses cold vapor atomic fluorescence spectroscopy (CVAFS).