Interannual covariation of the thermal conditions of the southeast asian low-latitude highlands and summer East Asia-Pacific teleconnection pattern

This study investigated the covariation of thermal conditions of the Southeast Asian low-latitude highlands (SEALLH) and variability of the summer East Asia-Pacific (EAP) or Pacific-Japan (PJ) teleconnection pattern using ERA5 reanalysis data and numerical experiments. Statistical analysis and physical diagnosis show that the EAP/PJ teleconnection pattern is significantly related to the seesaw mode of diabatic heating over the SEALLH in summer on the interannual time scale. When enhanced diabatic heating occurs over the central-northern SEALLH with weakened diabatic heating over the southern SEALLH, anomalous easterly and westerly winds, fitting the quasi-geostrophic theory, appear over the southern and central-northern SEALLH, receptively. These anomalous winds are propitious to the EAP/PJ teleconnection pattern in the "+, -, +" phase from the western North Pacific to northeast Asia. Once a significant relationship has been established in late spring, it can persist through to the following summer. Sensitivity experiments identified the key physical process linking the variability of the thermal conditions over the SEALLH to the summer EAP/PJ teleconnection pattern on an interannual time-scale.