Dataset: Clean Air Status and Trend Network (CASTNet): Wet chemistry

Methods

The methods followed in the creation of the dataset, including description of field, laboratory and processing steps, and quality control procedures

Current Methods

• Precipitation samples
  Started: 1994-04-06
  

  Weekly collection of precipation for chemical analysis is performed at two different sites. Precipitation amount, pH and conductivity analysis is performed at the sites. The sample is shipped to the NADP Central Analytical Lab in Illinois for analysis of pH, conductivity, Ca, Mg, K, Na, NH4, NO3, Cl, SO4.

• Ozone and deposition
  Started: 1994-01-01
  

  Seasonal continuous ozone (May through September), averaged hourly. Deposition (kg/ha) was calculated for chemicals reporting concentration in mg/l for annual, seasonal and montly time steps.

• Meteorological data
  Started: 1994-01-01
  

  Continuous meteorology averaged hourly includes ambient temperature at 2 and 10 m height, relative humidity, surface wetness, precipitation, wind speed and direction, solar radiation.

Past Methods (No longer in use)

• Sample analysis
  Started: 1995-07-04
  Ended: 1999-02-02

  Accumulated weekly samples; analysis includes SO2, HNO3, pH, conductivity, acidity and major ions.

Dataset Fields

Detailed documentation of the fields comprising the dataset, including the type of measurement, units where applicable, and any controlled vocabularies or code lists present in the data

Sampling Equipment

Equipment and software used to collect data, including how that equipment was used.

Site Characteristics

The spatial extent of the dataset site coverage, and descriptions of the spatial extent and context for the data collection

• Site Description

  Green Mountain National Forest, Stratton, just south of the Lye Brook Wilderness Area boundary. Summit of hill with southwest airflow.