Annual gradient maps of precipitation-weighted mean concentrations and depostion are available for NTN. These maps are available in PDF, KMZ, and grid formats.
About the maps
In 2011, the NADP Technical Committee instituted changes in the way NADP annual concentration and deposition maps are produced. It was decided to modify the original map series from a discrete contour map style to a continuous color gradient map style while incorporating an external, highly resolved precipitation dataset.
More information about the process used to create these maps is available.
NADP's Total Deposition Science Committee (TDEP) has developed total deposition (wet + dry) maps using a hybrid approach that combines measured air concentration, wet deposition data from NTN, and modeled deposition velocity and dry deposition data.
NADP's Critical Loads of Atmospheric Deposition Committee has developed a special subset of NTN maps has been developed that highlights the lower end of the concentration and deposition ranges.
The animated maps display the National Trends Network (NTN) concentration and deposition maps from 1985 to 2012 for sulfate, nitrate, and ammonium and the deposition maps for nitrogen from nitrate and ammonium. PDF and PowerPoint versions are available.
If you intend on reprinting any of these maps for use in a publication, please read our Use Conditions.