DOAS and ozonesondes observations for Antarctic Stratospheric Monitoring

YELA MARGARITA; DEFERRARI GUILLERMO; GIL M; IGLESIAS, J; NAVARRO, M; OCHOA H; PUENTEDURA,O

Granada

Congreso; SPARCSSG meeting; 2015

SPARC

The Antarctic polar vortex creates a quasi-circumpolar belt of strong meridional gradient of potential vorticity and temperature during the winter months. As a result the vortex acts as a closed vessel maintaining the isolation of the contained stratospheric air masses where the chemical species interacts with the Polar Stratospheric Clouds (PSC) formed in very low temperature conditions. Seasonal monitoring of BrO, OClO, NO2 and O3 inside, outside, and in the edge of the vortex during the formation, developing and collapsing periods is a useful way to study the effects of temporal evolution and meridional transport of these species. We show here results from a long term monitoring program for NO2 and O3 total column by visible spectroscopy in the Antarctic region that was initiated in February 1994 by an Agreement between INTA (Spain) and DNA (Argentina). At that time two unattended scanning spectrometers were deployed at Marambio station (Antarctic Peninsula, 64ºS, 56ºW) and Ushuaia (Tierra del Fuego, 55ºS, 68ºW). A third one was installed in Belgrano station (Continental Antarctica, 78ºS, 35ºW) in January 1995. The stations are separated by 10º in latitude and very close in longitude providing meridional cross-sections across the vortex. The observations were extended in 2011 by MAX-DOAS spectrometers to measures chlorine and bromine compounds at Begrano with the aim of separating the stratospheric and tropospheric column. Additional information on ozone profiles is provided by the routine ozonesondes program established in 1999 at Belgrano, in the core of the polar vortex. Long series are now available and particular attention has been paid to provide homogeneous sets of data, taking into account instrumental and spectral analysis changes. We report here the BrO, OClO, NO2 and O3 vertical column seasonal wave, interannual variability, diurnal variation and dependence with the light available.