National Atmospheric Deposition Program
National Trends Network
Trend Plots Notes

Individual Points

The individual points are annual average values.

For concentration plots, these values are calculated as the precipitation-weighted mean of all valid samples for that year.

For wet deposition plots, these values are the annual precipitation-weighted concentration multiplied by the total precipitation for the period.

Blue dots indicate points where the NADP data completion criteria were met for that year.

Red triangle indicate years where the NADP data completion criteria were not met.

More information about NADP data completion criteria is available

Trend Line

The trendline is composed of a three-year, centered, weighted-moving average value.
For each year of the data record, a three-year precipitation-weighted mean value was calculated. For example, the 1990 value for a site's trend line is the weighted mean concentration of all samples taken at the site in 1989, 1990 and 1991. Similarly, NADP completion criteria were calculated for each three year period. The trend line is shown only for periods when the completion criteria for the three year period were met.

National Atmospheric Deposition Program National Trends Network Trend Plots Notes

Individual Points The individual points are annual average values. For concentration plots, these values are calculated as the precipitation-weighted mean of all valid samples for that year. For wet deposition plots, these values are the annual precipitation-weighted concentration multiplied by the total precipitation for the period.
	Blue dots indicate points where the NADP data completion criteria were met for that year.
	Red triangle indicate years where the NADP data completion criteria were not met.
	More information about NADP data completion criteria is available
Trend Line
	The trendline is composed of a three-year, centered, weighted-moving average value. For each year of the data record, a three-year precipitation-weighted mean value was calculated. For example, the 1990 value for a site's trend line is the weighted mean concentration of all samples taken at the site in 1989, 1990 and 1991. Similarly, NADP completion criteria were calculated for each three year period. The trend line is shown only for periods when the completion criteria for the three year period were met.