Atmospheric Nitrogen Deposition to the New Jersey Coastal Waters and Its Implications

In situ measurements of atmospheric${\rm{NO}}_3^ - $and${\rm{NH}}_4^ + $at Sandy Hook on the northern New Jersey (USA) coast and at Tuckerton on the southern New Jersey coast reveal significant temporal and spatial variations of these inorganic N constituents. The mean concentration of${\rm{NO}}_3^ - $in precipitation was higher at Sandy Hook (44.6 micromo1/L) than at Tuckerton (29.1 micromo1/L). The mean concentration of${\rm{NH}}_4^ + $in precipitation exhibited a similar pattern, being higher at Sandy Hook (26.3 micromo1/L) than at Tuckerton (18.3 micromo1/L). Aerosol${\rm{NO}}_3^ - $and${\rm{NH}}_4^ + $concentrations at Sandy Hook were also higher than those at Tuckerton. On an annual basis, the total atmospheric deposition of${\rm{NO}}_3^ - $was estimated to be 51.1 mmol.m⁻².yr⁻¹ at Sandy Hook and 32.9 mmol.m⁻².yr⁻¹ at Tuckerton. For${\rm{NH}}_4^ + $, the total atmospheric deposition was 32.8 mmol.m⁻².yr⁻¹ at Sandy Hook and 20.3 mmol.m⁻².yr⁻¹ at Tuckerton. Wet deposition accounted for up to 89% of the total${\rm{NO}}_3^ - $deposition and 76-91% of the total${\rm{NH}}_4^ + $deposition on the New Jersey coast. By comparison,${\rm{NO}}_3^ - $and${\rm{NH}}_4^ + $concentrations are relatively low in estuarine waters of New Jersey. The annual mean${\rm{NO}}_3^ - $concentrations recorded in surface waters of the Mullica River-Great Bay Estuary near the Tuckerton atmospheric site during the 2002-2004 period were as follows: 12.1 micromo1/L for the upper estuary, 4.5 micromo1/L for the mid-estuary, 2.5 micromo1/L for the lower estuary, and 1.2 micromo1/L for the bay inlet area. The annual mean${\rm{NH}}_4^ + $concentrations in these waters were as follows: 1.5 micromo1/L for the upper estuary, 3.8 micromo1/L for the mid-estuary, 3.8 micromo1/L for the lower estuary, and 2.4 micromo1/L for the bay inlet area. In the Barnegat Bay-Little Egg Harbor Estuary, the mean concentrations of${\rm{NO}}_3^ - $plus${\rm{NO}}_2^ - $were