A Comparison of Wet-Deposition of Nitrogen from New NTN Site TX43 “Canonceta” with nearby Historical Trends Using Three Spatial Interpolation Techniques
Jeetendra K. Upadhyay
Texas AgriLife Research & Extension Center,
Texas A&M University,
Amarillo, TX USA
Wet deposition occurs when a particle or gas molecule is collected from the air and carried to the earth’s surface by precipitation. The major reactive species of nitrogen (N) in the atmosphere are nitrogen oxides, nitrate (NO3-) and ammonia (NH3). These components are highly reactive nitrogen species pool and are relatively soluble in water. They may be subjected to wet deposition through precipitation as nitrate (NO3-) and ammonium (NH4+). The primary, national network of wet deposition monitors is the National Atmospheric Deposition Program/National Trends Network (NADP/NTN). The agency’s monitoring sites provide weekly estimates of the wet deposition of nine inorganic chemicals: calcium, magnesium, potassium, sodium, ammonia, nitrate, chloride, sulfate and phosphate.
Field blanks are prepared quarterly for each CASTNET site. The filter packs used for the field blanks contain a nonstandard connection that cannot be installed in the sampling system in the field. The filter pack with the field blank is prepared and loaded according to standard CASTNET procedures. The field blanks are clearly identified and labeled to prohibit their removal from the resealable plastic bag used for shipping. When the field blank filter is returned from a site, it is unpacked, extracted, and analyzed following procedures for exposed filters. The field blank program and results for 2007 are summarized in the poster.