scholarly journals Biennial Oscillation Associated with the East Asian Summer Monsoon and Tropical Sea Surface Temperatures

1995 ◽  
Vol 73 (1) ◽  
pp. 105-124 ◽  
Author(s):  
Suhung Shen ◽  
K. -M. Lau
Keyword(s):  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Sea Surface ◽  
Sea Surface Temperatures ◽  
Surface Temperatures ◽  
Asian Summer ◽  
Tropical Sea ◽  
Biennial Oscillation

scholarly journals Sensitivity of the northeast Asian summer monsoon to tropical sea surface temperatures

2011 ◽  
Vol 38 (22) ◽  
pp. n/a-n/a ◽  
Author(s):  
Sang-Ik Shin ◽  
Prashant D. Sardeshmukh ◽  
Sang-Wook Yeh
Keyword(s):  
Summer Monsoon ◽  
Asian Summer Monsoon ◽  
Sea Surface ◽  
Sea Surface Temperatures ◽  
Surface Temperatures ◽  
Asian Summer ◽  
Northeast Asian ◽  
Tropical Sea

Relationship between sea surface temperature anomalies over tropical Atlantic in late spring and East Asian summer monsoon

2020 ◽  
Author(s):  
Joong-Bae Ahn ◽  
Yeon-Woo Choi
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Late Spring ◽  
Sea Surface ◽  
Tropical Atlantic ◽  
Asian Summer

<p>This study investigates the relationship between the preceding late spring Sea Surface Temperature (SST) over the tropical Atlantic and the East Asian Summer Monsoon (EASM) based on the observational data and Coupled Model Intercomparison Project Phase 5 (CMIP5) historical simulations. The results show that warm (cold) tropical Atlantic SST (TASST) during May tends to be followed by a strong (weak) EASM with positive (negative) precipitation anomalies over the subtropical frontal area. Evidence is also provided that the atmospheric teleconnections propagating in both east and west directions are the key mechanisms linking the EASM with the preceding May TASST. That is, the warm TASST anomaly during late spring can persist through the subsequent summer, which, in turn, induces the Gill-type Rossby wave response in the eastern Pacific, exciting the westward relay of the Atlantic signal, as well as the eastward propagation of the Rossby wave along the jet stream. Furthermore, the westward (eastward) propagating teleconnection signal may induce the anomalous anticyclone in the lower troposphere over the Philippine Sea (anomalous tropospheric anticyclone with barotropic structure over the Okhotsk Sea). The anomalous anticyclonic circulation over the Philippine Sea (Okhotsk Sea) brings warm and humid (cold) air to higher latitudes (lower latitudes). These two different types of air mass merge over the Baiu-Meiyu–Changma region, causing the enhanced subtropical frontal rainfall. To support the observational findings, CMIP5 historical simulations are also utilized. Most state-of-the-art CMIP5 models can simulate this relationship between May TASST and the EASM.</p><p>Reference: Choi, Y., Ahn, J. Possible mechanisms for the coupling between late spring sea surface temperature anomalies over tropical Atlantic and East Asian summer monsoon. Clim Dyn <strong>53, </strong>6995–7009 (2019) doi:10.1007/s00382-019-04970-3</p><p>Acknowledgment: This work was funded by the Korea Meteorological Administration Research and Development Program under Grant KMI2018-01213.</p><p> </p>

scholarly journals Disentangling fast and slow responses of the East Asian summer monsoon to reflecting and absorbing aerosol forcings

2017 ◽  
Author(s):  
Zhili Wang ◽  
Lei Lin ◽  
Meilin Yang ◽  
Yangyang Xu ◽  
Jiangnan Li
Keyword(s):  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Sea Surface ◽  
Slow Response ◽  
Total Response ◽  
Thermal Contrast ◽  
Response Component ◽  
Asian Summer

Abstract. We examine the roles of fast and slow responses in shaping the total equilibrium response of the East Asian summer monsoon (EASM) to reflecting (sulfate, SO4) and absorbing (black carbon, BC) aerosol forcings over the industrial era using the Community Earth System Model version 1. Our results show that there is a clear distinction between fast and slow responses of the EASM to aerosol forcings and the slow climate response due to aerosol-induced change in sea surface temperature plays an important role in the impacts of aerosols on the EASM. The EASM is weakened by a decrease in land-sea surface thermal contrast in the fast response component to SO4 forcing, whereas the weakening is more intensive by the changes in tropospheric thermodynamic and dynamic structures in the slow response component to SO4. The total climate adjustment caused by SO4 is a significant weakening of the EASM and a decrease in precipitation. The BC-induced fast adjustment strengthens the EASM both by increasing the local surface land-sea thermal contrast and shifting the East Asian subtropical jet northwards. BC-induced slow climate adjustment, however, weakens the EASM through altering the atmospheric temperature and circulation. Consequently, the EASM is enhanced north of 30° N but slightly reduced south of 30° N in the total response to BC. The spatial patterns of precipitation change over East Asia due to BC are similar in total response and slow response. This study highlights the importance of ocean response to aerosol forcings in driving the changes of the EASM.

Enhanced tropospheric biennial oscillation of the East Asian summer monsoon since the late-1970s

2021 ◽  
pp. 1-54
Author(s):  
Wen Chen ◽  
Kaiming Hu ◽  
Shangfeng Chen
Keyword(s):  
Summer Monsoon ◽  
North Pacific ◽  
East Asian Summer Monsoon ◽  
Western North Pacific ◽  
El Nino ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Tropospheric Biennial Oscillation ◽  
Asian Summer ◽  
Biennial Oscillation

Abstract The tropospheric biennial oscillation (TBO) of East Asian summer monsoon (EASM) has major impacts on East Asian climate. Here it is shown that, since the late-1970s, the TBO signal of EASM has strengthened significantly. The EASM TBO in wind anomalies undergoes a transition from a cyclone over the western North Pacific (WNPC) in preceding summer to an anticyclone over the western North Pacific (WNPAC) in following summer, with the anomalies strengthening remarkably after the late-1970s. Correspondingly, the biennial component of precipitation anomalies in eastern China show different distributions. Both observational and numerical simulation analyses demonstrate that these changes are caused by the westward shift of El Niño warming and enhanced Indo-Pacific and Atlantic-Pacific coupling. The positive sea surface temperature (SST) anomalies associated with the TBO of EASM shift toward the central Pacific after the late-1970s, which favor the strengthening of the WNPC and cause a weakened EASM. In following summer, both the north Indian Ocean and tropical north Atlantic SST warming are closely coupled with El Niño since the late-1970s, which favor the strengthening of WNPAC and cause an intensified EASM. Together, these changes provide more favorable background state for the transition of circulation anomalies over the western North Pacific, giving rise to enhanced biennial variability in EASM in the late-1970s.

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