Winter Lower Stratosphere Research Articles

Numerical Experiments with a General Circulation Model Concerning the Distribution of Ozone in the Stratosphere

The distribution of ozone below 60 km altitude has been simulated in two experiments employing a nine-layer quasi-geostrophic spectral model and linear parameterization of ozone photochemistry, the first of which included thermal and orographic forcing of the planetary scale waves, while the second omitted it. The first experiment exhibited a high latitude winter ozone buildup which was due to a Brewer-Dodson circulation forced by large amplitude (planetary scale) waves in the winter lower stratosphere. Photochemistry was also found to be important down to lower altitudes (20 km) in the summer stratosphere than had previously been supposed.

Energy flux and convergence patterns in the lower and middle stratosphere during the IQSY

AbstractThe vertical and horizontal fluxes of energy by large‐scale standing waves have been estimated on a monthly basis for the IQSY for the 100–10 mb region. A large upward flux into the region occurs in winter some of which passes into the atmosphere above 10 mb, where it may exceed the energy generated there by radiative processes. The meridional wave energy flux diverges from the 40°–60°N region and converges in both high and low latitudes in winter. The total energy flux convergence pattern shows that the polar night jet in the lower stratosphere in winter is a source of kinetic energy; when the jet collapses in the spring the same region turns into a strong sink and it is noted that while this was a gradual process in 1965 and occupied three months, there was a large absorption in March 1964 that dominated the energetics pattern in spring. The largest energy absorption occurs with the largest energy flux into the region, thus supporting previous suggestions that the spring warming is ultimately dependent on tropospheric events. The adiabatic approximation was used in the flux computations and the role of radiative processes in the observed events is briefly discussed.