Interannual variability of estimated monthly N deposition to coastal waters and its sensitivity to atmospheric variables input

PINEDA ROJAS, A.L.; VENEGAS, L.E.

Barcelona, España

Conferencia; SOLAS (Surface Ocean-Lower Atmosphere Study) Open Science Conference 2009; 2009

The Surface Ocean-Lower Atmosphere Study

Atmospheric nitrogen (N) produced by increasing NOx emissions can be transferred tocoastal waters through deposition processes. The complex relationships betweendeposition processes and atmospheric and emission conditions, make N deposition tovary considerably in space and time.In this work, possible variations in monthly oxidized N deposition estimates associated to changes in atmospheric variables are quantified applying atmospheric dispersion models. The deposition of N to de la Plata River during years 1999, 2000 and 2001 is studied. The interannual variation of monthly dry deposition values (10-160%) was mostly controlled by the frequency of unstable atmospheric conditions, the photochemical activity of the atmosphere and the frequency of winds towards the river. The interannual variation of monthly wet deposition reached a factor of 124 as a result of the variation of the frequency of rainy hours and  precipitation rates in a factor of 4 and 3, respectively.