NADP > Networks > National Trends Network > NTN Gradient Maps

Annual NTN Maps by Year

Annual gradient maps of precipitation-weighted mean concentrations and deposition are available for NTN. These maps are available in PDF and grid formats (up to 2018).

If you intend on reprinting any of these maps for use in a publication, please read our Use Conditions.

2020
ConcentrationDeposition
Lab pHPDF Lab H+PDF
SO4 PDF SO4PDF
NO3PDF NO3PDF
NH4PDF NH4PDF
CaPDF CaPDF
MgPDF MgPDF
KPDF KPDF
NaPDF NaPDF
ClPDF ClPDF
NPDF
S+NPDF
Total PrecipitationPDF
2019
ConcentrationDeposition
Lab pHPDF Lab H+PDF
SO4 PDF SO4PDF
NO3PDF NO3PDF
NH4PDF NH4PDF
CaPDF CaPDF
MgPDF MgPDF
KPDF KPDF
NaPDF NaPDF
ClPDF ClPDF
NPDF
S+NPDF
Total PrecipitationPDF
2018
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDF
2017
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDF
2016
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
2015
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
2014
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
2013
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
2012
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
2011
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
2010
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
2009
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
2008
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
2007
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
2006
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
2005
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
2004
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
2003
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
2002
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
2001
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
2000
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
1999
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
1998
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
1997
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
1996
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
1995
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
1994
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
1993
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
1992
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
1991
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
1990
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
1989
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
1988
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
1987
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
1986
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid
1985
ConcentrationDeposition
Lab pHPDFGrid Lab H+PDFGrid
SO4 PDF Grid SO4PDFGrid
NO3PDFGrid NO3PDFGrid
NH4PDFGrid NH4PDFGrid
CaPDFGrid CaPDFGrid
MgPDFGrid MgPDFGrid
KPDFGrid KPDFGrid
NaPDFGrid NaPDFGrid
ClPDFGrid ClPDFGrid
NPDFGrid
S+NPDFGrid
Total PrecipitationPDFGrid