1. Data Summit: Overview of the Clean Air Status and Trends Network (CASTNET)
Gary Lear
U.S. EPA Office of Air and Radiation
Clean Air Markets Division
12 February 2008

2. Locations of CASTNET Sites
Operating since 1987
Currently 87 sites in 40 states
Regionally representative locations
Rural and often ecologically important locations, including 26 National Parks
Sites conform to specific siting criteria
Minimal influence from local sources

3. CASTNET Measurements Sampler
CASTNET filter pack assembly
Sampler
Filter pack - Teflon®, Nylon®, and Whatman®
Chemical analysis
Laboratory extraction and ion chromatography
Gaseous species
HNO3, O3, SO2
Particle species
NO3, NH4, SO4, Base cations
Sampling frequency
168 hours (1 week)
Sampling schedule
Tuesday to Tuesday
Sampling height
10 m
Continuous sampling
Ozone
Continuous Meteorology
Temperature, precipitation, relative humidity, solar radiation, wind speed, wind direction
Landuse and Vegetation (site observations)
Vegetation, Leaf Area Index (LAI), Percent green leaf out

4. Ozone Measurements Daily zero/span precision checks
Historically performed weekly
Calibrated against NIST reference standards every 6 months
Annual external audit
Are in process of certification for compliance determinations

5. Data Products Meteorology Vegetation Air Concentrations NADP
Wet Deposition
Dry Deposition
Velocities
Concentration
Aggregations
Dry Deposition
Flux
Wet Deposition
Interpolations
Air
Concentration
Interpolations
Total Deposition
Flux

6. Data Accessibility EPA http://www.epa.gov/castnet
Production
Database
Public
Access
Prepackaged datasets for ozone, meteorological data, model output
Data query wizard
Map images
Request Oracle login from CAMD
SQL*Net
ODBC
GIS

7. Active Database Connections
Organization
Direction
Type of Data
Frequency
NADP In
Wet deposition
Quarterly
Out
Total Deposition
Annual
AIRNow
Ozone
Daily
NAtCHem
In/Out
Air concentrations, deposition

8. Future Changes Eliminating data query wizard
Returning to static datasets available via http/ftp
Updated daily or monthly
Additional sites contributing to AIRNow
All sites by 2009
Ozone and other Part 58 compliant data to AQS