Influence Of Wave Activity Research Articles

Erratum to: “Influence of wave activity on the composition of the polar stratosphere”

Erratum to: “Influence of wave activity on the composition of the polar stratosphere”

Influence of wave activity on the composition of the polar stratosphere

The planetary wave impact on the polar vortex stability, polar stratosphere temperature, and content of ozone and other gases was simulated with the global chemical–climatic model of the lower and middle atmosphere. It was found that the planetary waves propagating from the troposphere into the stratosphere differently affect the gas content of the Arctic and Antarctic stratosphere. In the Arctic region, the degree of wave activity critically affects the polar vortex formation, the appearance of polar stratospheric clouds, the halogen activation on their surface, and ozone anomaly formation. Ozone anomalies in the Arctic region as a rule are not formed at high wave activity and can be registered at low activity. In the Antarctic Regions, wave activity affects the stability of polar vortex and the depth of ozone holes, which are formed at almost any wave activity, and the minimal ozone values depend on the strong or weak wave activity that is registered in specific years.

Quasi-stationary planetary waves in late winter Antarctic stratosphere temperature as a possible indicator of spring total ozone

Abstract. Stratospheric preconditions for the annual Antarctic ozone hole are analyzed using the amplitude of quasi-stationary planetary waves in temperature as a predictor of total ozone column behaviour. It is found that the quasi-stationary wave amplitude in August is highly correlated with September–November total ozone over Antarctica with correlation coefficient (r) as high as 0.83 indicating that quasi-stationary wave effects in late winter have a persisting influence on the evolution of the ozone hole during the following three months. Correlation maxima are found in both the lower and middle stratosphere. These likely result from the influence of wave activity on ozone depletion due to chemical processes, and ozone accumulation due to large-scale ozone transport, respectively. Both correlation maxima indicate that spring total ozone tends to increase in the case of amplified activity of quasi-stationary waves in late winter. Since the stationary wave number one dominates the planetary waves that propagate into the Antarctic stratosphere in late austral winter, it is largely responsible for the stationary zonal asymmetry of the ozone hole relative to the South Pole. Processes associated with zonally asymmetric ozone and temperature which possibly contribute to differences in the persistence and location of the correlation maxima are discussed.

How permeable is the edge of the Arctic vortex: Model studies of winter 1999–2000

The edge of the Arctic vortex constitutes a strong barrier to transport; however, the extent of isolation of the vortex air as a function of altitude and season is relatively poorly quantified. In this study, by examining the transport of midlatitude air parcels across the vortex edge into the vortex, we analyze the permeability of the vortex edge. With the three‐dimensional version of CLaMS (Chemical Lagrangian Model of the Stratosphere) we explore the dilution of the vortex air due to mixing in winter 1999–2000. An artificial, passive tracer was initialized on 1 December 1999 inside the polar vortex with a value of 100% and with a value of zero outside the polar vortex. Using several different definitions of the vortex edge, the resulting intrusions of midlatitude air into the vortex show the same mean features. This demonstrates that the diagnosed dilution does not strongly depend on the details of the definition of the vortex edge. At about the end of March 2000, the vertical structure of the vortex consisted of well‐isolated, pure vortex layers around 500 K and 750 K, with some more diluted layers in between and at the vortex bottom. The influence of wave activity on the evolution of the intrusion layers is studied. The divergence of the Eliassen‐Palm flux shows such a high variability during the whole period that it is not possible to assess a direct causality of certain intrusion layers and some specific patterns. Some characteristics of the vortex edge, in particular the shape of the gradient of potential vorticity (PV), can influence the dilution of the vortex. In cases without a distinct maximum in the PV gradient, the defined “vortex edge” may vary substantially from day to day. The comparison of some properties of the vortex (wind speed, PV field, area of the vortex, the maximum of the PV gradient) of undisturbed versus diluted layers and the variation in time of the intrusions were analyzed. All observed intrusions begin in conditions of weak PV gradient, indicating that the value of the maximum of the PV gradient may be used as a quantitative measure of the permeability of the vortex edge.