HR: 0800h
AN: A51B-0030    [Abstracts]
TI: Analyzing the Seasonal Cycle of N2O
AU: * Yung, Y L
EM: yly@gps.caltech.edu
AF: Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, 91125
AU: Ku, W
EM: kwl@gps.caltech.edu
AF: Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, 91125
AU: Ku, W
EM: kwl@gps.caltech.edu
AF: Department of Physics, The Chinese University of Hong Kong, Hong Kong, 2609
AU: Jiang, X
EM: xun@gps.caltech.edu
AF: Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, 91125
AU: Jiang, X
EM: xun@gps.caltech.edu
AF: Department of Environmental Science and Engineering, California Institute of Technology, Pasadena, 91125
AU: Shia, R
EM: rls@gps.caltech.edu
AF: Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, 91125
AU: Li, Q
EM: qli@mail.jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, Pasadena, MS 183-501
AU: Elkins, J W
EM: James.W.Elkins@noaa.gov
AF: National Oceanic and Atmospheric Administration, Climate Monitoring and Diagnostics Laboratory, Boulder, CO 80303
AB: We carried out a systematic study of the seasonal cycle in the nitrous oxide (N2O) data collected by National Oceanic and Atmospheric Administration - Climate Monitoring and Diagnostics Laboratory (NOAA-CMDL). In order to confirm the weak seasonal signal in the observations, we applied the multitaper method for spectrum analysis [Ghil et al., 2002] and impose the criterion that the seasonal signal must be over 99 % significant. The N2O seasonal cycle signals from seven stations pass this quality control. The stations are Alert (82­aN, 62­aW), Barrow (71­aN, 157­aW), Mace Head (53­aN, 10­aW), Cape Kumukahi (19­aN, 155­aW), Cape Matatula (14­aS, 171­aW), Cape Grim (41­aS, 145­aE) and South Pole (90­aS, 102­aW). Conspicuous by its absence is the lack of a seasonal cycle signal that satisfies the above criterion at Mauna Loa (19.5­aN, 155.6­aW), despite a long time series of high quality data. The seasonal cycle of N2O in the northern hemisphere shows the influence of the stratosphere (Nevison et al. 2004; Liao et al. 2004); the seasonal cycle of N2O southern hemisphere shows the influence of an ocean source (Nevison et al. 2005). We obtain new results for the tropics that suggest the possibility of a larger source of N2O from biomass burning.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 0365 Troposphere: composition and chemistry
DE: 0368 Troposphere: constituent transport and chemistry
DE: 0426 Biosphere/atmosphere interactions (0315)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005