Chemical fluctuations associated with vertically propagating equatorial Kelvin waves

Journal Article · Tue Nov 20 00:00:00 EST 1990 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JD095iD12p20491· OSTI ID:5205640

Salby, M L; Callaghan, P ^[1]; Soloman, S ^[2]; Garcia, R R ^[3]

---

1. Univ. of Colorado, Boulder (USA)
2. Univ. of Colorado, Boulder (USA) NOAA, Boulder, CO (USA)
3. National Center for Atmospheric Research, Boulder, CO (USA)

Satellite retrievals of ozone and nitrogen dioxide from the Nimbus-7 Limb Infrared Monitor of the Stratosphere (LIMS) reveal distinct spectral features which are collocated in frequency with Kelvin wave temperature fluctuations. These features represent a significant component of the unsteady variance in retrievals of O{sub 3} and nighttime NO{sub 2} in the tropics and are very similar to Kelvin wave temperature disturbances. Chemical fluctuations occur symmetrically about the equator, in phase across the tropics, and propagate downward, all consistent with the behavior of equatorial Kelvin waves. The phase structure of ozone perturbations mirrors that of temperature fluctuations in the upper stratosphere and mesosphere, only shifted 180{degree}. The regular phase tilt with altitude disappears in the middle to lower stratosphere, where it is replaced by more or less barotropic behavior. That change in phase structure marks a transition fromn photochemical control in the upper stratosphere and mesosphere to dynamical control in the lower stratosphere. Fluctuations in ozone are consistent with dynamical and chemical mechanisms operating on that species. The response of ozone in a detailed photochemical calculation driven by observed temperature variability locks into agreement with the observed ozone variability above about 4 mbar, where O{sub 3} is under photochemical control. At lower altitudes, vertical transport is able to explain both the magnitude and phase of the observed fluctuations in ozone. The same considerations have only mixed success in explaining the observed variability of nitrogen dioxide. The amplitude of nighttime NO{sub 2} fluctuations is underestimated in the photochemical calculation by about a factor of 2. Although large enough to explain the discrepancy, contributions from vertical transport have the wrong phase.

• OSTI ID: 5205640
• Journal Information: Journal of Geophysical Research; (United States), Vol. 95:D12; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
NITROGEN DIOXIDE
ECOLOGICAL CONCENTRATION
OZONE
STRATOSPHERE
ATMOSPHERIC CHEMISTRY
TEMPERATURE GRADIENTS
ATMOSPHERIC CIRCULATION
CORRELATIONS
DAILY VARIATIONS
EQUATOR
FLUCTUATIONS
MESOSPHERE
PHASE STUDIES
PHOTOCHEMICAL REACTIONS
SATELLITES
TROPICAL REGIONS
WAVE PROPAGATION
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISTRY
EARTH ATMOSPHERE
NITROGEN COMPOUNDS
NITROGEN OXIDES
OXIDES
OXYGEN COMPOUNDS
VARIATIONS
540110*