Inter-decadal variability of the heat source over the Tibetan Plateau

The vertically integrated apparent heat source ( $$\langle {\mathrm{Q}}_{1}\rangle $$ ), reflecting features and evolutions of the heat budget, is a key variable in the changing climate of the Tibetan Plateau (TP). Despite previous investigations, characteristics of $$\langle {\mathrm{Q}}_{1}\rangle $$ on the inter-decadal timescale have not received sufficient attention. By extracting the inter-decadal variability (IDV) using the ensemble empirical mode decomposition (EEMD) method, results from our analysis reveal the dominant role of IDV of $$\langle {Q}_{1}\rangle $$ over the TP. $$\langle {Q}_{1}\rangle $$ variability is closely related to the Indian Ocean sea surface temperature (IOSST) and Pacific Decadal Oscillation (PDO) at the inter-decadal timescale. During the IOSST and PDO in-phase combinations (i.e., positive IOSST with positive PDO phase and negative IOSST with negative PDO phase), a low pressure (high pressure) system occured over the TP which was accompanied by cyclonic (anticyclone) circulation bring cold (warm) air from the North Pacific (Indian Ocean), resulting in an obvious net loss (gain) of heat over the central and northeastern TP. In the future, IDV will still dominate the change of $$\langle {Q}_{1}\rangle $$ over the TP, having a shortened cycle and reduced amplitude under a scenario of intensified emissions.