COMPARISON OF MICROTOPS Ⅱ OZONEMETER AND OMI SATELLITE TOTAL OZONE COLUMN MEASUREMENTS IN MANILA, PHILIPPINES FROM FEB-OCT 2011

摘要

Total ozone column (TOC) measurements were performed in De La Salle University, Manila, Philippines (14.71° N, 121.58° E) last February— October 2011 using a hand-held Microtops Ⅱ Ozonemeter (MII). These are the first local measurements of total ozone column in the Philippines. The Microtops Ⅱ instrument measures ozone at wavelengths 305.5, 312.5, and 320 nm. Measurements using the device were taken during midday (local noontime) and when the sun is clearly seen. Monthly averages were taken from February to October of 2011 in Manila, which is currently considered to be one of the most polluted cities in Asia. When compared to the total ozone column readings from the Ozone Monitoring Instrument (OMI) satellite, the Microtops Ⅱ yielded a difference of-3-15%. The MII Ozone Spectrophotometer provided data of the TOC averaging 280.36 ± 15.13 Dobson units (DU) while OMI TOC data averaged at 262.23 ± 19.26 DU. Analyses have shown the importance of proper user training in the use of the MII instrument especially during the rainy season.