Engineering topics

Kendig, D. J.

Publications and source records attributed to Kendig, D. J..

3 records

NASA NTRS1992

Tropical behavior of mesospheric ozone as observed by SMM

The seasonal behavior of low latitude mesospheric ozone, as observed by the SMM satellite solar occultation experiment, is detailed for the 1985-1989 period. Annual as well as semi-annual waves are observed in the 50-70 km altitude region. In the latitude range of +/- 30 deg the ozone phase and amplitude are functions of temperature and seasonal changes in solar flux. Temperature is the controlling factor for the equatorial region and seasonal changes in solar flux become more dominant at latitudes outside the equatorial zone (greater than +/- 15 deg). There is a hemispheric asymmetry in the ozone annual wave in the 20-30 deg region, with Northern Hemispheric ozone having a larger amplitude than Southern Hemispheric ozone.

Aikin, A. C.↗

NASA NTRS1991

Temperature trends in the lower mesosphere

The largest atmospheric temperature changes due to the increase of greenhouse gases are expected in the 40 to 60 km altitude region, where enhanced infrared cooling decreases the temperature. Ten-year (1980-1990) temperature trends at 55 km and 0.4 mb, derived using data from the ground-based lidar at Haute Provence, (France), and the SSU-instrument channel 47X on several satellites, are presented. These data show temperature decreases that are as large and in some cases exceed predictions based on current models. At 44 deg N, the ground-based lidar and satellite techniques give a negative trend of -0.10 + or - 0.04 percent per year and -0.14 + or - 0.02 percent per year, respectively. Agreement between these two data sets based on different measurement techniques gives confidence in the detected trends at this latitude. Further analysis of the SSU 47X satellite data between 45 deg S and 45 deg N indicates a maximum decline of 0.16 percent per year near 30 deg N. A minimum trend decrease of 0.07 percent per year is detected between 20 and 30 deg S. Based on NOAA satellite radiance observations, these long-term temperature changes are larger than changes at any of the other stratospheric levels below 55 km monitored during this period.

Aikin, A. C.↗

NASA NTRS1989

An intercomparison of mesospheric ozone profiles determined by the UVSP and SAGE II solar occultation experiments

A comparison is made of individual UVSP and SAGE II mesospheric ozone profiles between 50 and 70 km altitude as determined by the solar occultation technique. The generally good agreement between the two data sets below about 57 km leads to the conclusion that they may be considered as complementary, thus extending the effective altitude range of both. Comparison of the long-term ozone trend at 55.5 km shows a systematic difference of a few percent between the two measurements.

Aikin, A. C.↗