HR: 1330h
AN: B32B-0392    [PDF]
TI: The Bio-atmospheric N Cycle: A Story of Multiple Element Interactions, N, C, S, Atmospheric Chemistry and the Climate System
AU: * Holland, E A
EM: eholland@ucar.edu
AF: Biogeosceinces Initiative and Atmospheric Chemistry Division National Center for Atmospheric Research, PO Box 3000, Boulder, CO 80305 United States
AB: The bio-atmospheric N plays a key role in the climate system through regulation of atmospheric greenhouse concentrations, including nitrous oxide, carbon dioxide, methane, and tropospheric ozone, as well as impacting aerosol abundance. I will examine the evidence for including the full bio-atmospheric nitrogen cycle into earth system models. The most obvious is the impact of the bio-atmospheric nitrogen cycle on nitrous and nitric oxide emissions. Nitrogen deposition significantly impacts terrestrial carbon dioxide uptake, as well as influencing leaf level nitrogen concentrations that in turn impact stomatal conductance. The importance of this interaction has been recognized by the atmospheric chemistry community and a modeling project is underway to quantify and compare global estimates of N deposition, including ammonia(um) and NOy and its impact on the carbon cycle. Ammonia impacts sulfate aerosol abundance as well as reacting with nitrate form aerosols that act as cloud condensation nuclei to he potential to significantly impact the water cycle. The SRES emission projections and an accumulating body of evidence suggest that sulfur dioxide emissions will decline over the next century, while carbon and nitrogen emissions, carbon dioxide, methane, carbon monoxide, and VOCs, and NOx are all projected to continue to increase. The long-term goal is an Earth System model that allows examination of the complex interactions of biology, climate, atmospheric chemistry and humans.
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0315 Biosphere/atmosphere interactions
DE: 0345 Pollution--urban and regional (0305)
DE: 0368 Troposphere--constituent transport and chemistry
DE: 0400 Biogeosciences
SC: Biogeosciences [B]
MN: 2003 Fall Meeting