Search Results

You are looking at 1 - 3 of 3 items for :

  • Author or Editor: Jae H. Park x
  • Journal of the Atmospheric Sciences x
  • Refine by Access: All Content x
Clear All Modify Search
Jae H. Park

Abstract

Absorption of solar radiation by O2 in the Schumann-Runge band region is important not only for the production of O(3P) in the atmosphere, but also for H2O and NO photodissociations which depend upon the rotational structure of the O2 absorption lines. The equivalent mean absorption cross sections for the O2 Schumann-Runge bands and NO band intensities are computed and presented in a form to be applicable in calculations of the O2, H2O and NO photodissociation rates under varied atmospheric conditions.

Full access
Jae H. Park and Julius London

Abstract

The distributions of minor atmospheric constituents, principally O3 and O(3P), and their contributions to the heat sources and sinks in the earth’s middle atmosphere (30–100 km) are investigated. The latitudinal and seasonal distributions of radiative heating rates for the region 30–100 km are computed considering the absorption of solar UV by O2 and O3 and the chemical heat release by O(3P) recombination. Absorption of solar radiation by O3 is responsible for most of the radiative heating in the region 30–75 km. Between 75 and 90 km the heating rate is relatively small and is contributed to about equally by absorption by O2 and O3. Above 90 km the heating rate due to absorption by O O2 is of major importance, although non-equilibrium production of O(3P) in the summer results in reduced heating rates at these levels. At 100 km the “effective” heating rate is ∼40K day−1 at high latitudes during the summer. Recombination of O(3P) in the winter polar mesosphere and lower thermosphere results in a significant heat source for that region.

Meridional gradients of computed heating rates in the upper atmosphere are found to be generally larger than previous results. The implications of this distribution with regard to the dynamics of this region is discussed.

Full access
Jae H. Park and James M. Russell III

Abstract

Regions of low stratospheric ozone that are anticorrelated with HCl, NO, and NO2 levels have been observed in the Arctic and Antarctic summers of 1992 and 1993 by the Halogen Occultation Experiment on the UARS platform. The low ozone areas are confined to the ∼8–45 mb (∼33–21 km) region and poleward of ∼60° in each hemisphere. While low polar summer ozone has been observed before, this is the first time simultaneous observations of relevant nitrogen and chlorine chemical species have been made. The phenomenon appears to be a recurring geophysical feature, and the satellite data should provide an excellent opportunity to improve our understanding of the chemistry causing these conditions.

Full access