Table 1.

Geographic details associated with the nine study sites and the date range of data used in this work. Samples analyzed in this study were based on liquid precipitation samples and excludes influence of frozen precipitation. Precipitation data are based on years that had a full 12 months of data.

Program	Site	Lat/Lon(°)	Altitude (m ASL)	Time Period	Number of Samples	Annual Precipitation (mm)
NADP/NTN	Olympic National Park-Hoh Ranger Station (WA14)	47.86/−123.93	176	January 2007 - December 2016	321	2746
NADP/NTN	Hopland (CA45)	39.00/−123.93	253	January 2007 - December 2016	221	758
NADP/NTN	Tanbark Flat (CA42)	34.21/−117.76	853	January 2007 - December 2016	158	463
NADP/NTN	Edwin B. Forsythe National Wildlife Refuge (NJ00)	39.47/−74.43	2	January 2007 - December 2016	319	994
NADP/NTN	Cape Romain National Wildlife Refuge (SCO5)	32.94/−79.66	1	January 2007 - December 2016	361	1261
NADP/NTN	Everglades National Park Research Center (FL11)	25.39/−80.68	2	January 2007 - December 2016	374	1450
NADP/NTN	Mauna Loa (HI00)	19.54/−155.58	3399	June 1980 - September 1993	291	402
AEROCE	Tudor Hill, Bermuda (BTT)	32.27/−64.87	51	January 1989 - February 1997, July 2006 - June 2009	953	2688
EANET	Metro Manila, Philippines (MM)	14.64/−121.08	87	February 2007 - December 2016	285	1996