HR: 1330h
AN: B32B-0391    [PDF]
TI: Organic Nitrogen in Atmospheric Drops and Particles: Concentrations, (Limited) Speciation, and Chemical Transformations
AU: * Anastasio, C
EM: canastasio@ucdavis.edu
AF: Department of Land, Air & Water Resources, University of California - Davis, One Shields Avenue, Davis, CA 95616-8627 United States
AU: Zhang, Q
EM: zhangq@cires.colorado.edu
AF: Department of Land, Air & Water Resources, University of California - Davis, One Shields Avenue, Davis, CA 95616-8627 United States
AU: Zhang, Q
EM: zhangq@cires.colorado.edu
AF: Cooperative Institute for Research in Environmental Sciences, University of Colorado, 216 UCB, Boulder, CO 80309-0216 United States
AB: While quite a bit is known of the concentrations, speciation, and chemistry of inorganic forms of nitrogen in the atmosphere, the same cannot be said for organic forms. Despite this, there is growing evidence that organic N (ON) is ubiquitous in the atmosphere, especially in atmospheric condensed phases such as fog/cloud drops and aerosol particles. Although the major compounds that make up organic N are generally unknown, as are the sources of these compounds, it is clear that there are significant fluxes of ON between the atmosphere and ecosystems. It also appears that organic N can have significant effects in both spheres. The goal of our recent work in this area has been to better describe the atmospheric component of the biogeochemistry of organic nitrogen. Based on particle, gas, and fogwater samples from Northern California we have made three major findings: 1) Organic N represents a significant component, approximately 20%, of the total atmospheric N loading in these samples. This is broadly consistent with studies from other locations. 2) Amino compounds, primarily as combined amino acids, account for approximately 20% of the measured ON in our condensed phase samples. Given the properties of amino acids, these compounds could significantly affect the chemical and physical properties of atmospheric particles. 3) Organic nitrogen in atmospheric particles and drops is transformed to inorganic forms - primarily ammonium, nitrate, and nitrogen oxides (NOx) - during exposure to sunlight and/or ozone. These chemical reactions likely increase the bioavailability of the condensed phase nitrogen pool and enhance its biological effects after deposition to ecosystems.
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0317 Chemical kinetic and photochemical properties
DE: 0365 Troposphere--composition and chemistry
DE: 0400 Biogeosciences
DE: 1615 Biogeochemical processes (4805)
SC: Biogeosciences [B]
MN: 2003 Fall Meeting