Solar‐induced oscillations in the stratosphere: A myth or reality?

Abstract

The response of the stratosphere to 27-day variability in solar activity is studied by using ozone and temperature data obtained from the SCR (Selective Chopper Radiometer) and the BUV (backscattered ultraviolet) experiments on Nimbus 4. In the upper stratosphere (~ 2 mbar), where solar UV effects are likely to be maximum, the zonally averaged temperature and ozone mixing ratio in the tropics seem to be related to changes in conventional indices of solar activity over several solar rotations. The temperature and ozone are, however, anticorrelated, with temperature varying in phase and ozone out of phase with solar activity. The tropical oscillations appear to be manifestations of oscillations at high latitudes that are very strong during fall-spring epoch of both the hemispheres. The high-and low-latitude oscillations are almost 180 ø out of phase with a transition region at mid-latitudes (30ø-40ø). Their spectral characteristics and phase suggest a complex interaction of dynamical and chemical processes in the upper stratosphere. This conclusion is further strengthened from the inferred changes in ozone sensitivity with respect to temperature, which shows a continuous decrease from the tropics to high latitudes in both the hemispheres.Atmos. Sci., 40, 769, 1983.Volland, H., and J. Schaefer, Cause and effect in some types of sunweather relationship, Geophys. Res. Lett., 6, 17, 1979.

The 11-year solar-cycle effects on the temperature in the upper-stratosphere and mesosphere: Part I—Assessment of observations

“…However, its association with the solar cycle was less obvious than the response at tropical latitudes because of the larger shortterm variability. Based on the vertical shape of the response and their latitudinal expansion, dynamical causes already suggested (Chandra, 1985;Chanin and Keckhut, 1991) are confirmed here by the seasonal patterns of SSU data analyses. The observed differences in solar response between the two hemispheres can be understood by the differences in the dynamic stability of the vortexes.…”

Long-term Variation of Upper Stratospheric Circulation in the Northern Hemisphere in December

“…Of course, the period of the present analysis is too short to obtain conclusive results. It is, however, noted that for short-term variations of solar UV such as are related to the solar rotation, there exists increasing evidence of ozone and temperature response in the upper stratosphere (Chandra, 1985;Hood, 1987;Keating et al, 1987). Another problem is how to explain the large amplitude of the variation of mean zonal winds to the assumed solar forcing (Fig.…”

The effect of the 11-year solar-cycle on the temperature in the upper-stratosphere and mesosphere: Part II numerical simulations and the role of planetary waves

“…Observations and simulations were qualitatively and quantitatively consistent in the equatorial/tropical band and support the hypothesis of a direct photochemical ozone response in addition to a direct radiative heating by solar ultraviolet variations. However, some observations of temperature changes, mainly at higher latitudes (Chandra, 1985(Chandra, , 1986Chanin and Keckhut, 1991;Hauchecorne et al, 1991;Keckhut, 1995;Hood and Jirikowic, 1991) and in the lower stratosphere (Labitzke and van Loon, 1988) show larger responses that were not reproduced by models and cannot be explained by chemical and radiative considerations alone. On the 11-year time scale, ozone responds qualitatively as predicted by photochemical models (McCormack and Hood, 1996;Chandra, 1986) with some differences in magnitude, while the upper stratospheric temperature responds as expected only in the equatorial/tropical region (Keckhut et al, 2005).…”