Influences of teleconnections on climate variables in northern and northeastern Thailand

Abstract

Teleconnection events can influence normal regional weather patterns and affect weather forecast accuracy. To improve the forecast ability, the relationship between main teleconnections such as El Niño–Southern Oscillation (ENSO), Indian Ocean Dipole (IOD), Madden–Julian Oscillation (MJO), and climate variables (rainfall, maximum and minimum surface temperature, vertical mixing ratio, and vertical maximum temperature) was established using lag correlation coefficient and t-test methods. The results reveal moderately significant correlations between El Niño, positive IOD and rainfall, and vertical mixing ratio, which can be associated with lower-than-usual rainfall. The coincidence between El Niño and positive IOD events can worsen drought. Even though the MJO and regional weather correlations were significant, the magnitude of correlation coefficients was negligible. In addition, the spatiotemporal distribution of ENSO shows that the strong El Niño has more influence on rainfall anomalies in the post-1980s. Since there are insufficient studies on the association between teleconnections and climate variables, especially vertical mixing ratio, our findings can benefit prediction development for teleconnection-induced regional climate anomalies for extreme events and water management preparations in northern and northeastern Thailand. HIGHLIGHTS ENSO events have significant correlations in northern compared with northeastern Thailand.; El Niño, positive IOD, and climate variables have significant negative correlations in the dry season in northern Thailand.; La Niña, negative IOD, and climate variables have a less significant negative correlation in northern and northeastern Thailand.; MJO has significant correlations with rainfall and temperature.;

Keywords

• el niño-southern oscillation (enso)
• indian ocean dipole (iod)
• madden-julian oscillation (mjo)
• maximum temperature
• mixing ratio
• rainfall