Total ozone patterns from Singapore data

Abstract

Eleven years of daily total ozone measurements from 1979 at Singapore using a Dobson spectrophotometer are presented as monthly averages. The temporal variation is found to be consistent with observations at two other near-equatorial stations as well as satellite derived data. No obvious trends are discernible in the Singapore records.

The Singapore Meteorological Service has been monitoring total ozone since February 1979 with a Dobson spectrophotometer (No. 7) at its Upper-Air Observatory (1.2°N/103.53°E). The instrument is on loan from the U.K. Meteorological Office and is maintained through funding assistance from the World Meteorological Organisation. The observing programme is to obtain at least three direct-sun total ozone values each morning, weather permitting. Additionally a weekly Umkehr measurement is also attempted whenever possible. The direct-sun values obtained daily as well as direct-sun observations from the Umkehr experiments are the basis for the Dobson data discussed in this paper.