Surface carbon dioxide concentrations were measured using a non-dispersive infrared carbon dioxide
sensor at Lampang Rajabhat University from April to May 2013 and at the University of the PhilippinesDiliman
campus starting September 2013. Factors influencing the variations in these measurements were
determined using multiple linear regression and a Lagrangian transport model. Air temperature and sea
level pressure were the dominant meteorological factors that affect the CO2 variations. However, these
factors are not enough. Surface CO2 flux and transboundary transport needs to be considered as well