scholarly journals Long‐term changes in the relationship between stratospheric circulation and East Asian winter monsoon

2015 ◽  
Vol 16 (3) ◽  
pp. 359-365 ◽  
Author(s):  
Ke Wei ◽  
Masaaki Takahashi ◽  
Wen Chen
Keyword(s):  
East Asian Winter Monsoon ◽  
East Asian ◽  
Winter Monsoon ◽  
Asian Winter Monsoon ◽  
Long Term Changes ◽  
Stratospheric Circulation ◽  
The Relationship

scholarly journals Zonal shift in the cold airmass stream of the East Asian winter monsoon

2021 ◽  
Author(s):  
Qian Liu ◽  
Guixing Chen
Keyword(s):  
East Asian Winter Monsoon ◽  
East Asian ◽  
Winter Monsoon ◽  
Phase Changes ◽  
Dominant Factor ◽  
Northwestern Pacific ◽  
Asian Winter Monsoon ◽  
Peak Location ◽  
Interdecadal Timescale

Abstract The East Asian winter monsoon exhibits long-term variations in intensity and spatial pattern, though the latter one is less understood. To investigate the long-term spatial variations of the EAWM and their possible causes, we propose a new position index of the EAWM by quantifying the low-level East Asian stream (EAS) of cold airmass in the Lagrangian sense. Based on the new-defined index, we find that the EAS undergoes an evident zonal shift between two channels over the land and coast. At interdecadal timescale, the peak location of the EAS is displaced eastward, with an increasing southward cold airmass flux at the coast since the mid-1960s. The interannual shift of the EAS presents not only the zonal oscillation of peak location between two channels but also the width changes of coastal channel over the northwestern Pacific. These shifts in the EAS are related to the strength changes of two source cold airmass streams from Siberia or Bering Sea, which are associated with the phase changes in the upper-tropospheric atmospheric teleconnections. At interdecadal timescale, the phase change in the North Atlantic Oscillation modulates the zonal shift in the EAS via the East Atlantic-West Russia teleconnection. At interannual timescale, the Pacific/North American teleconnection becomes the dominant factor altering the zonal shift and width change of the EAS.

Interdecadal change in the relationship between the winter North Pacific storm track and the East Asian winter monsoon

2021 ◽  
pp. 1-57
Author(s):  
Minghao Yang ◽  
Chongyin Li ◽  
Xin Li ◽  
Yanke Tan ◽  
Xiong Chen ◽  
...  
Keyword(s):  
Atmospheric Circulation ◽  
North Pacific ◽  
East Asian Winter Monsoon ◽  
East Asian ◽  
Storm Track ◽  
Winter Monsoon ◽  
Interdecadal Change ◽  
Asian Winter Monsoon ◽  
The Relationship ◽  
North Pacific Storm Track

AbstractBased on the daily NCEP reanalysis, the present study investigates the interdecadal change in the relationship between the winter North Pacific storm track (WNPST) and the East Asian winter monsoon (EAWM), and evaluates the WNPST-EAWM relationship in 17 CMIP6 models. The results show that the out-of-phase WNPST-EAWM relationship underwent an interdecadal change in the mid-1980s. The WNPST-EAWM relationship became less significant during P2 (1990-2015). The atmospheric circulation anomaly related to the EAWM during P1 (1955-1980) is more robust than that during P2. The interdecadal weakening WNPST-EAWM relationship may be attributed to the interdecadal damping WNPST-EAWM interaction. The EAWM-related anomalous baroclinic energy conversion and moisture effect, including meridional and vertical eddy moisture fluxes, contribute to the significant attenuation of the WNPST during P1. The transient eddy-induced dynamic forcing and thermal forcing anomalies, as well as the barotropic process represented by the local Eliassen-Palm flux divergence associated with WNPST, can also significantly manipulate the upper-tropospheric jet during P1. However, the atmospheric circulation and interaction between the WNPST and EAWM during P2 are not as significant as those during P1. The effect of ENSO on the WNPST is significantly different before and after the mid-1980s. After the mid-1980s, the WNPST shows the characteristic of moving equatorward during El Niño events. It seems that ENSO takes over the WNPST from the EAWM after the mid-1980s. In addition, except for BCC-ESM1, CanESM5 and SAM0-UNICON, most of the CMIP6 models cannot reproduce the significant out-of-phase WNPST-EAWM relationship.

scholarly journals Change in Relationship between the East Asian Winter Monsoon and the East Asian Jet Stream during the 1998–99 Regime Shift

2019 ◽  
Vol 32 (18) ◽  
pp. 6163-6175 ◽  
Author(s):  
Se-Yong Song ◽  
Sang-Wook Yeh ◽  
Jae-Heung Park
Keyword(s):  
East Asian Winter Monsoon ◽  
East Asian ◽  
Hadley Circulation ◽  
Winter Monsoon ◽  
Jet Stream ◽  
Decadal Change ◽  
Reanalysis Dataset ◽  
Asian Winter Monsoon ◽  
East Asian Jet Stream ◽  
The Relationship

Abstract A composite analysis was conducted on the reanalysis dataset for 1979–2016, along with an idealized model experiment to show that the relationship between the East Asian jet stream (EAJS) and the East Asian winter monsoon (EAWM) is nonstationary. The relationship between EAWM and the EAJS weakened during the late 1990s. This decadal change in the EAJS–EAWM relationship was mainly due to a change in the secondary circulation across the EAJS between two contrasting periods, induced by the northward shift of the EAJS. A possible mechanism associated with the decadal change in meridional displacement of the EAJS is proposed. The enhanced convective activity in the western tropical Pacific after the late 1990s results in stronger Hadley circulation that could have contributed to the northward displacement of the Hadley circulation boundary latitude. Subsequently, this leads to the northward shift of the EAJS. Therefore, it is necessary to define a new EAJS index to account for the EAWM variability based on the change in the oceanic and atmospheric mean state across the late 1990s.

scholarly journals On the long-term interannual variability of the east Asian winter monsoon

2005 ◽  
Vol 32 (21) ◽  
Author(s):  
Rosanne D'Arrigo ◽  
Rob Wilson ◽  
Fotis Panagiotopoulos ◽  
Bingyi Wu
Keyword(s):  
Interannual Variability ◽  
East Asian Winter Monsoon ◽  
East Asian ◽  
Winter Monsoon ◽  
Asian Winter Monsoon

scholarly journals Interdecadal Variations of the East Asian Winter Monsoon in CMIP5 Preindustrial Simulations

2020 ◽  
Vol 33 (2) ◽  
pp. 559-575 ◽  
Author(s):  
Jiapeng Miao ◽  
Tao Wang ◽  
Huijun Wang
Keyword(s):  
North Pacific ◽  
East Asian Winter Monsoon ◽  
East Asian ◽  
Winter Monsoon ◽  
Climate System ◽  
Asian Winter Monsoon ◽  
The North ◽  
The North Pacific ◽  
Sst Anomalies

AbstractIn this study, focusing on the interdecadal time scale, we investigate the internal variability of the East Asian winter monsoon (EAWM) using output from 19 coupled models’ long-term preindustrial control (piControl) simulations within phase 5 of the Coupled Model Intercomparison Program (CMIP5). In total, we identify 53 cases of significant interdecadal weakening of the EAWM from these 19 piControl simulations. In most weakening cases, both the Siberian high and the East Asian trough are significantly weakened. The East Asian jet stream in the upper troposphere shifts poleward. Southerly wind anomalies are evident over East Asia in the lower troposphere. At the same time, both the Arctic Oscillation (AO) and the North Pacific Oscillation are in their positive phases. Associated anomalous anticyclonic circulation can be found over the North Pacific. Additionally, the North Pacific shows negative Pacific decadal oscillation (PDO)-like sea surface temperature (SST) anomalies. In contrast, we also analyzed 49 cases of significant strengthening of the EAWM, and the atmospheric and oceanic anomalies show opposite signals with the weakening cases. This suggests that internal variabilities of the climate system can also cause interdecadal variations of the EAWM. In addition, the phase shifting of the AO is likely the main reason for the EAWM’s interdecadal variations in the unforced long-term simulations. Further numerical experiments using the Community Atmosphere Model, version 4 (CAM4), deny the causal relationship between the interdecadal variations of EAWM and PDO-like SST anomalies. This study also implies that the internal variabilities of the climate system could contribute to the observed interdecadal weakening of the EAWM around the mid-1980s.

scholarly journals Sedimentary Dynamics of the Central South Yellow Sea Revealing the Relation Between East Asian Summer and Winter Monsoon Over the Past 6000 years

2021 ◽  
Vol 9 ◽  
Author(s):  
Wenzhe Lyu ◽  
Tengfei Fu ◽  
Zhangxi Hu ◽  
Ying Zhong Tang ◽  
Guangquan Chen ◽  
...  
Keyword(s):  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
East Asian Winter Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Winter Monsoon ◽  
Asian Winter Monsoon ◽  
Asian Summer ◽  
Sedimentary Dynamics ◽  
The Relationship

The mud areas of East Asian marginal seas record considerable information about regional environmental evolution. However, debate continues regarding the relative importance of the major factors in regional sedimentary dynamics, i.e., the East Asian summer monsoon, East Asian winter monsoon, and oceanic circulation. In this study, we investigated the characteristics of grain size from a gravity core obtained in the South Yellow Sea to reveal changes in sedimentary dynamics since 6,000 years BP, and to elucidate the relationship between the East Asian summer monsoon and the East Asian winter monsoon. We found that the mean grain size was in the range of 6.9–7.8 Φ, the sediment was poorly sorted within a small range (1.2, 1.5), and the M values from 4.7 to 6.7 μm and most of the C values from 24 to 65 μm suggested pelagic suspension transport. Results indicated that the intensity of both the East Asian summer monsoon and the East Asian winter monsoon showed a fluctuating trend of decrease after approximately 6,000 years BP, and that the relationship between them was generally anticorrelated. Based on these results, we suggest that positive correlation between the East Asian summer monsoon and the East Asian winter monsoon usually results in the fall or establishment of ancient dynasties in the Central Plains of China and that negative correlation between them is controlled by strong solar radiation. Weakening of solar radiation diminishes its control of the intensity of (and thus the correlation between) the East Asian summer monsoon and the East Asian winter monsoon, at which time the North Atlantic Oscillation plays a modulating role.

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