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Comparison between Ushuaia and Marambio situation

The position of the Marambio (64.2 S, 56.7 W) station in the new coordinate system is inside the vortex at the 475 K isentropic level, especially in the winter and spring seasons. In contrast, the position of the Ushuaia station (59.9 S, 68.3 W) is mostly outside the vortex, see Pazmiño et al, 2000.

The ozone evolution over these stations is quite different, especially in 1997 and 1999: the ozone evolution over Ushuaia corresponds mostly to the mid-latitude behavior while the evolution over Marambio is of typical polar behavior. The temporal evolution of the total ozone over Ushuaia and Marambio classified with respect to the position of the polar vortex at 475 K is represented in figure 7 for the 1997-1999 period. In autumn, both stations show similar ozone evolution and the outside vortex situations are predominant. The values are around 290 DU for both stations. The ozone amounts increase slowly up to July.

Figure 7. Temporal ozone evolution over Ushuaia and Marambio stations classified with respect to the position of the polar vortex at 475 K in the 1997-1999 period. The inside, edge and outside vortex situations are represented by open circles, pluses, and dots respectively.

In winter, the poorer sampling of the inner vortex and vortex edge situations at Ushuaia still allows us to observe the rapid ozone decline from August to mid-October, essentially in 1997 and 1998. In spring, the ozone values reach less than 150 DU over Marambio and 200 DU over Ushuaia in the September-October period.

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