We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
The Unstable Relationship Between the Precipitation Dipole Pattern in the Tibetan Plateau and Summer NAO.
- Authors
Liu, Yong; Chen, Huopo; Hu, Xiaoyu
- Abstract
Substantial progress has been made in understanding the relationship between summer precipitation in the Tibetan Plateau (TP) and North Atlantic Oscillation (NAO), but impacts of the summer NAO on precipitation spatial pattern remain controversial. Using the long‐term observational and reanalysis datasets, we have identified the intimate relationship between summer NAO and TP precipitation dipole pattern has been weakened since the late 1990s. Changes in regional atmospheric circulation induced by the asymmetrical wave propagation structure along the Eurasian continent are responsible for this weakened linkage. Further analyses revealed that the wave propagation anomalies are mainly induced by interdecadal change of summer NAO, which is attributed to the Atlantic multidecadal oscillation (AMO) variations. Moreover, the model simulations derived from the Geophysical Fluid Dynamics Laboratory (GFDL AM2.1) provide direct evidence to demonstrate that the AMO phase transition contributes to the unstable relationship between the summer NAO and precipitation dipole pattern in the eastern TP. Plain Language Summary: The spatial mode of summer precipitation in the TP is of great significance to the regional climate and ecosystem. Previous studies have indicated the summer NAO exerts great impacts on the generation of precipitation dipole pattern in the eastern TP. However, based on the statistical analysis and dynamic diagnose, we have found the relationship between the summer NAO and TP precipitation dipole pattern is nonstationary and characterized by a significant interdecadal change. In the late 1990s, the enhanced wave activity flux propagation emanating from the North Atlantic can give rise to the change in regional atmospheric circulation on the TP, which results in the anomalous cyclonic circulation on the eastern TP and prejudices the generation of precipitation dipole pattern. Evidence indicates that the interdecadal shift of the summer NAO and the AMO could be responsible for this unstable relationship. The warm AMO is favorable to bring more precipitation in the eastern TP and is not conducive to the occurrence of precipitation dipole pattern. Additionally, the model simulations conducted by the GFDL present evidence to highlight the important role in modulating the relationship between the summer NAO and dipole precipitation pattern in the eastern TP. Key Points: The relationship between the summer North Atlantic Oscillation (NAO) and Tibetan Plateau precipitation dipole pattern has been weakened since the late 1990sThe wave propagation structure induced by the summer NAO anomaly is the major cause of the unstable linkageThe interdecadal shift of Atlantic multidecadal oscillation is partly responsible for the unstable relationship of the summer precipitation pattern with NAO
- Subjects
TIBETAN Plateau; ATLANTIC multidecadal oscillation; GEOPHYSICAL fluid dynamics; NORTH Atlantic oscillation; ATMOSPHERIC circulation
- Publication
Geophysical Research Letters, 2021, Vol 48, Issue 4, p1
- ISSN
0094-8276
- Publication type
Article
- DOI
10.1029/2020GL091941