Summer Atmospheric Heat Sources over the Western–Central Tibetan Plateau: An Integrated Analysis of Multiple Reanalysis and Satellite Datasets

Abstract

Multiple bias-corrected top-quality reanalysis datasets, gauge-based observations, and selected satellite products are synthetically employed to revisit the climatology and variability of the summer atmospheric heat sources over the Tibetan Plateau (TP). Verification-based selection and ensemble-mean methods are utilized to combine various datasets. Different from previous works, this study pays special attention to estimating the total heat source (TH) and its components over the data-void western plateau (70°–85°E), including the surface sensible heat (SH), latent heat released by precipitation (LH), and net radiation flux (RD). Consistent with previous studies, the climatology of summer SH (LH) typically increases (decreases) from southeast to northwest. Generally, LH dominates TH over most of the TP. A notable new finding is a minimum TH area over the high-altitude region of the northwestern TP, where the Karakoram mountain range is located. We find that during the period of 1984–2006, TH shows insignificant trends over the eastern and central TP, whereas it exhibits an evident increasing trend over the western TP that is attributed to the rising tendency of LH before 1996 and to that of RD after 1996. The year-to-year variation of TH over the central–eastern TP is highly correlated with that of LH, but that is not the case over the western TP. It is also worth noting that the variations of TH in each summer month are not significantly correlated with each other, and hence study of the interannual variation of the TP heat sources should consider the remarkable subseasonal variations.

Large‐Scale Circulation Environment and Microphysical Characteristics of the Cloud Systems Over the Tibetan Plateau in Boreal Summer

“…Usually, the extreme rainfall is consequences of the strong convective cloud systems under the favorable circulation patterns. It is found that the TP is a great heat source due to the strong surface heat flux in boreal summer, resulting in frequent and flourishing convective clouds as reported by many studies (e.g., Luo & Yanai, 1984; Wang et al, 2019; Xie & Wang, 2018). Figure 1 shows the precipitation statistical results from 1961 to 2012 for the ETP and WTP.…”

The Long-Term Change of Latent Heat Flux over the Western Tibetan Plateau

“…From August 2014 to January 2017, the R 2 and RMSE between LE MEP OBS and LE EC are 0.64 and 6.6 W m −2 , respectively. Previous studies showed that the LE estimations with the RMSE values between 4.7 and 23.8 W m −2 may be used to reveal the features of LE over the TP [3,13]. Thus, our resulting LE is acceptable, which implies that the MEP model can be used to estimate LE over the western TP.…”

“…It plays an important role in elevating the heat sources into the middle troposphere over the Eurasian continent in summer, and profoundly influences the Asian summer monsoon, regional energy and water cycles, and environment changes [1]. The TP has been experiencing warming and wetting since the mid-1950s, which has led to an array of complex meteorological, hydrological, and ecological changes [2][3][4][5][6]. Therefore, to better understand the land-atmosphere interactions underlying regional and global climate pattern, the reliable estimations of surface thermal effects of the TP are essential.…”

The influence of the precipitation recycling process on the shift to heavy precipitation over the Tibetan Plateau in the summer

“…This has reduced the external cycle of heavy precipitation over the eastern TP. Due to the strengthening of the heating source (Xie and Wang, 2019) and the "up-and-over" process (Dong et al, 2016), the moisture flux near the southern boundary of the western TP is increasing (He et al, 2021). In addition, the enhanced warming over the TP has caused glacier melting, lake expansion and increasing evaporation, all of which promote the intensification of the precipitation recycling process.…”