Influences of the Atlantic Ocean on the summer precipitation of the southeastern Tibetan Plateau

Abstract

The southeastern Tibetan Plateau is one of the predominant summer rainfall regions in the world and is also the crucial water vapor channel of the Asian summer monsoon. The rainfall variability in the region influences not only the local communities but also downstream communities in East Asia. However, previous studies have exhibited large rainfall biases in this region in state‐of‐the‐art climate models. Understanding the observed rainfall variability provides an opportunity to identify the origin of model biases and to lay a foundation for improving model performance. In this study, the interannual variability of the summer precipitation (May–September) over the southeastern Tibetan Plateau was investigated based on National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis monthly mean data from 1979 to 2010. The associated atmospheric circulation anomalies of the southeastern Tibetan Plateau summer precipitation (SET_PR) display a North Atlantic Ocean‐Europe‐Asia teleconnection pattern, indicating a possible role of the Atlantic climate in the SET_PR. Further studies have revealed that the Atlantic sea surface temperature (SST) anomalies have the greatest influence on the SET_PR via the Rossby wave response, whereas the SST anomalies in the Indo‐Pacific have less of an influence on the SET_PR because their main impacts are confined to the western North Pacific subtropical high and the monsoonal circulation there. This paper also documents the detailed spatial pattern of the atmospheric circulation anomalies associated with the SET_PR and Atlantic SST year‐to‐year variability.

Impact of the North Atlantic Oscillation on the Dipole Oscillation of summer precipitation over the central and eastern Tibetan Plateau

“…Furthermore, the regression patterns of the 200 hPa Eliassen-Palm (EP) stationary wave flux with the NAO index exhibit an unusual EP stationary wave flux along the aforementioned wave train, illustrating the downstream energy flux from the North Atlantic to the TP (Figure 3). Thus, based on these detailed analyses of geopotential heights, stationary wave flux and previous research (Bothe et al, 2010Zhu et al, 2011;Gao et al, 2013), the aforementioned wave train related to the NAO acts as a bridge to connect the North Atlantic to the TP.…”

“…Yang et al (2004) documented that the strength and shift of the Middle East jet stream, the associated stationary wave activity flux and high-frequency eddy activities may be affected by the winter and spring North Atlantic Oscillation (NAO), which subsequently affect the downstream Asian summer monsoon system that dominates the TP. Gao et al (2013) revealed that Atlantic sea surface temperature anomalies have the greatest control over the southeastern TP summer precipitation via a Rossby wave response. Using mass balance measurements of the Zhadang Glacier and combined atmospheric-glacier modelling, Mölg et al (2014) reported that the mid-latitude climate should be considered as a possible driver of past and future glacier changes over the southern TP; this finding agrees with the underestimated effects of mid-latitude westerlies on precipitation over the TP .…”

Atmospheric moisture budget and its regulation on the variability of summer precipitation over the Tibetan Plateau

“…The precipitation over the TP, which is situated in the Asian monsoon region, is influenced greatly by changes in large-scale monsoon circulation. Many studies have also emphasized the importance of Eurasian snow cover [Xu and Lu, 1992], sea surface temperature (SST) in the Atlantic Ocean and the Indian Oceans [Gao et al, 2013;Hu and Duan, 2015], and atmospheric internal variability [e.g., Liu and Yin, 2001;Zhu et al, 2011; for regulating the spatial and temporal patterns of TP summer precipitation.…”

Interannual variation of precipitation over the Hengduan Mountains during rainy season

“…It forms as a result of the propagation of quasi-stationary Rossby waves along the Asian jet and has a wavelength of about 60 ∘ in the zonal direction (Lu et al, 2002;Enomoto et al, 2003;Sato and Takahashi, 2003;Kosaka et al, 2009Kosaka et al, , 2012. SRP is viewed as a part of the circumglobal teleconnection (CGT) pattern that extends zonally through the whole hemisphere (Ding and Wang, 2005;Yasui and Watanabe, 2010;Chen and Huang, 2012;Lin, 2014) and can influence climate over a broad area, including precipitation and temperature over TP and East Asia (Liu and Yin, 2001;Wu, 2002;Bothe et al, 2010Bothe et al, , 2011Gao et al, 2013). Gao et al (2013) studied the variation of summer precipitation over the southeastern part of TP, and emphasized the importance of Atlantic SST anomalies by triggering CGT-like zonal wave pattern.…”

“…SRP is viewed as a part of the circumglobal teleconnection (CGT) pattern that extends zonally through the whole hemisphere (Ding and Wang, 2005;Yasui and Watanabe, 2010;Chen and Huang, 2012;Lin, 2014) and can influence climate over a broad area, including precipitation and temperature over TP and East Asia (Liu and Yin, 2001;Wu, 2002;Bothe et al, 2010Bothe et al, , 2011Gao et al, 2013). Gao et al (2013) studied the variation of summer precipitation over the southeastern part of TP, and emphasized the importance of Atlantic SST anomalies by triggering CGT-like zonal wave pattern. At present, the researches about the HMs are rare, and most of them focus on the analysis of main meteorological elements.…”