TY  - JOUR
T1  - Long-Term Trend Analysis of Tropospheric Total Column Ozone in Africa
AU - , K.O. Ogunjobi AU - , V.O. Ajayi AU - , I.A. Balogun 
JO  - Research Journal of Applied Sciences
VL  - 2
IS  - 3
SP  - 280
EP  - 284
PY  - 2007
DA  - 2001/08/19
SN  - 1815-932x
DO  - rjasci.2007.280.284
UR  - https://makhillpublications.co/view-article.php?doi=rjasci.2007.280.284
KW  - Photochemical
KW  -troposphere
KW  -total column ozone
KW  -trend
KW  -biomass burning
AB  - General characteristics and trends of tropospheric total column ozone content were investigated using data available at the World Ozone and Ultraviolet Data Centre (WOUDC). Observations are made at four different stations in Africa namely Nairobi (Lat.1&deg; 16` S; Long. 36&deg; 48` E), Lagos (Lat. 6&deg; 27` N ; Long. 3&deg; 24` E ) ,  Cairo (Lat. 29&deg; 52` N; Long.31&deg; 20` E)  and  Aswan (Lat. 24&deg; 05`N; Long.32&deg; 56`  E). The annual mean total column ozone estimated were 254.35 &plusmn; 8.25DU, 254.89 &plusmn; 6.07DU, 290.89 &plusmn; 6.27DU, and 270.28 &plusmn; 4.94DU for Nairobi, Lagos, Cairo and Aswan respectively.  An increasing trend in total column ozone of 0.89DU / yr (or 0.35% year<SUP>-1</SUP>) was observed at Nairobi while Lagos recorded a trend of 1.02DU/yr (or 0.40% year<SUP>-1</SUP>).   A similar but slightly positive trends of 0.10DU /yr (or 0.04 % year<SUP>-1</SUP>) and 0.04DU/yr (or 0.02 % year<SUP>-1</SUP>) were observed for Cairo and Aswan respectively.  The annual value of column ozone reported at Cairo, are lower in the 1990s than in the previous decade: total ozone amounts are 3.9±0.02 lower in 1990s than those observed in the 1980s.
ER  -