NO2 TOTAL COLUMN EVOLUTION DURING THE 1989 SPRING AT ANTARCTICA PENINSULA

Ground-based visible differential absorption spectrometry during twilight has been used for NO2, total column observations at the Antarctica Peninsula, Marambio Base (64S, 56W), during the austral spring of 1989 (9 September to 25 November). Results show moderate NO2 vertical column levels of 1.5 to 2.5 x 10(15) molec cm-2 in thc morning and 2 to 3 x 10(15) molec cm-2 in the evening until middle October, highly modulated by planetary wave activity. From that date until the end of the period, a steady increase occurs which is associated with the rising of lower stratosphere temperature as the vortex weakens. reaching values of 5 x 10(15) molec cm-2 in late November. with small a.m.-p.m. differences. NO2 is found to be positively correlated to both total ozone and 50 hPa temperature during the entire spring. However, when analyzing the departures from linear trends, a highly negative correlation has been observed from day 301 onwards.