"Analysis of aerosol optical depth, total ozone column and precipitable" by Floyd Rey Padua Plando

Analysis of aerosol optical depth, total ozone column and precipitable water retrieved from microtops-II ozonemeter over Manila, Philippines

Date of Publication

8-2016

Document Type

Master's Thesis

Degree Name

Master of Science in Physics

Subject Categories

Physics

College

College of Science

Department/Unit

Physics

Thesis Adviser

Edgar A. Vallar

Defense Panel Chair

Maria Cecilia D. Galvez

Defense Panel Member

Christopher T. Que
Ernest P. Macalalad

Abstract/Summary

Ground-based measurements of Total Ozone Column (TOC), Aerosol Optical Depth (AOD) and Precipitable Water (PW) were conducted in the Science and Technology Research Center (STRC) of De La Salle University, Manila, Philippines in the years 2011, 2014, 2015 and 2016 using a hand-held MicroTOPS II (MII) ozonemeter mounted in a tripod. Measurements using this device were taken from 0900H – 1700H (LT). For TOC analysis, Majority of the TOC values fall between 200-300 DU. MII TOC data was correlated to OMI and yielded an R = 0.512 and RMSE = 8.51 suggesting a moderate relationship between the instruments. It was also correlated with AQMS-DOAS and TECO data and obtained R = 0.103 and 0.0907, respectively suggesting weak relationships for two sets of correlation. Another, to check if the ground ozone in DLSU site exceeded the US EPA standard, hourly and 8-hour ozone measurement was done for AQMS-DOAS and TECO. For hourly measurement, only 1.73% and 1.26% exceeded the hourly standard value of 71.07 ppb and for 8-hour measurement, 22.5% and 15.3% exceeded the standard value of 31.48 ppb for AQMS-DOAS and TECO, respectively. For AOD analysis, higher mean values and large variations were retrieved for UV wavelengths (305, 312 and 320 nm), while lower mean values and less variations of mean AODs for near-IR wavelengths (936 and 1020 nm). High spectral dependence was seen in 2014 and lower in 2015 for UV wavelengths, but a drift in curvature had seen for near-IR wavelengths for 2011 and 2014. Also, high correlation coefficients were achieved in the curvature effect at different wavelengths using the Ångstrӧm power law, with R2 values of 0.987, 0.992, 0.986, and 0.985 for second-order polynomial fitting. Further, majority of the distribution falls under fine-mode aerosols with convex curvature according to the secondorder polynomial fit. For PW analysis, majority of the data points fall between the ranges of 2-4 cm (86.43% of the total data points). Relationship between MII PW and MODIS Terra was done and achieved a correlation coefficient R = 0.293 and RMSE = 1.56 signifying a weak, linear correlation between two data sets. Another, relationship of MII PW was done with PW AERONET and achieved a statistically significant value of R = 0.560 and RMSE = 0.744 suggesting a moderate, linear relationship. Lastly, estimation of PW were done using the functional forms adapted from the study of Maghrabi and Al Dahjani (2013). Among these 15 functional forms, Butler model had the best predictability in terms of closeness to mean PW and having a good MBE and RMSE, which were both approaching to zero. Meanwhile, Adeyemi (Kano) and Reitan models overestimated their PW values and had the worst predictability in terms of their SD and CV values.

Abstract Format

html

Language

English

Format

Electronic

Accession Number

CDTG006844

Shelf Location

Archives, The Learning Common's, 12F Henry Sy Sr. Hall

Physical Description

1 computer optical disc; 4 3/4 in.

Keywords

Atmospheric ozone--Philippines--Manila

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Embargo Period

10-10-2024

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