Comparative study of the total ozone column over Maitri, Antarctica during 1997, 2002 and 2003

摘要

The total ozone (TOZ) column was measured using a Microtop Sun-photometer at Maitri (70° 45′S, 11° 44′E), Antarctica during the 16th, 21st and 22nd Indian Scientific Expedition to Antarctic. A comparative study of the TOZ column at Maitri, Antarctica was made to understand the behaviour of the ozone hole. The observations showed a direct relationship between the stratospheric temperature anomaly and year-to-year variation in TOZ. The minimum TOZ observed at Maitri, Antarctica during spring was 135DU (Dobson unit), 185DU and 126 DU in 1997, 2002 and 2003, respectively. The ozone hole in 2003 was much deeper and had a longer duration. The observations showed that chemical loss of ozone over Maitri during the ozone hole period in 2003 was increased by 18.6% when compared with 1997 and 42% when compared with 2002. The observations at Maitri also showed an event of major stratospheric wanning along with surface warming during 2002. A temporary sudden rise in the TOZ column before the recovery period (days 300-315) was also observed and found to be overlapping in all the observational years.