Open AccessWavelet spectrum analysis of PM10 data in Bangkok, Thailand
Author(s) -
Panatcha Anusasananan
Publication year - 2019
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1380/1/012017
Subject(s) - wavelet , wavelet transform , spectral density , environmental science , atmospheric sciences , mathematics , coherence (philosophical gambling strategy) , statistics , climatology , physics , geology , computer science , artificial intelligence
PM10 is one of the key factors which influences the air quality in metropolitan areas throughout the world. In this research we investigate the variation period of PM10 concentration and its temporal patterns from 2009 to 2017 in Bangkok, Thailand using wavelet spectrum analysis. We also utilize the cross wavelet transform to study the potential relation between PM10 and the temperature. From the wavelet power spectrum of PM10, we can distinguish two dominant bands, one in the period between 8-16 months and the other between 1-8 months. The first oscillation is obviously related to natural annual periodicities that the high power occurs from December 2011to February 2015. The PM10 concentrations are high in winter and low in the rainy season. The second band between 1-8 months is the transient pattern with very high concentration of PM10 occurs only in the year 2013. Wavelet spectrum of the temperature is similar in pattern for it shows the strong annual signal and the lowest temperature band between 4-8 months. The cross wavelet transform (XWT) power spectra between PM10 and the temperature show significant common power, in the 8-16 month band from November 2009 to June 2016, and in the 1-8 month band around November 2012 to February 2014. The wavelet transform coherence (WTC) spectra show that PM10 and the temperature co-varied out of phase during all observed time intervals. This indicates the high seasonal dependence between PM10 and the temperature. Knowledge of the variation period of PM10 concentration and its evolution feature in Bangkok area will help the authorities to better prepare for public health and environmental hazard from the next PM10 pollution.