Seasonal variation of the East Asian Subtropical Westerly Jet and its association with the heating field over East Asia

2005 ◽  
Vol 22 (6) ◽  
pp. 831-840 ◽  
Author(s):  
Kuang Xueyuan ◽  
Zhang Yaocun
Keyword(s):  
Seasonal Variation ◽  
East Asia ◽  
East Asian ◽  
Westerly Jet ◽  
Subtropical Westerly Jet

scholarly journals Potential Influence of Arctic Sea Ice to the Interannual Variations of East Asian Spring Precipitation*

2016 ◽  
Vol 29 (8) ◽  
pp. 2797-2813 ◽  
Author(s):  
Zhiwei Wu ◽  
Xinxin Li ◽  
Yanjie Li ◽  
Yun Li
Keyword(s):  
Sea Ice ◽  
East Asia ◽  
Wave Train ◽  
East Asian ◽  
Arctic Sea Ice ◽  
Interannual Variations ◽  
Spring Precipitation ◽  
Westerly Jet ◽  
Arctic Sea ◽  
Subtropical Westerly Jet

Abstract Arctic sea ice (ASI) and its potential climatic impacts have received increasing attention during the past decades, yet the relevant mechanisms are far from being understood, particularly how anomalous ASI affects climate in midlatitudes. The spring precipitation takes up as much as 30% of the annual total and significantly influences agriculture in East Asia. Here, observed evidence and numerical experiment results show that the ASI variability in the Norwegian Sea and the Barents Sea in the preceding winter is intimately connected with interannual variations of the East Asian spring precipitation (EAP). The former can explain about 14% of the total variance of the latter. The ASI anomalies persist from winter through the ensuing spring and excite downstream teleconnections of a distinct Rossby wave train prevailing over the Eurasian continent. For the reduced ASI, such a wave train pattern is usually associated with an anomalous low pressure center over the Mongolian plateau, which accelerates the East Asian subtropical westerly jet. The intensified subtropical westerly jet, concurrent with lower-level convergence and upper-level divergence, enhances the local convection and consequently favors rich spring precipitation over East Asia. For the excessive ASI, the situation tends to be opposite. Given that seasonal prediction of the EAP remains a challenging issue, the winter ASI variability may provide another potential predictability source besides El Niño–Southern Oscillation.

scholarly journals Dominant Modes of Tropospheric Ozone Variation over East Asia from GOME Observations

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Yi Liu ◽  
Yuli Zhang ◽  
Yong Wang ◽  
Chuanxi Liu ◽  
Zhaonan Cai ◽  
...  
Keyword(s):  
East Asia ◽  
Tropospheric Ozone ◽  
Asian Summer Monsoon ◽  
Principal Component ◽  
Total Variance ◽  
Ozone Production ◽  
The Tibetan Plateau ◽  
Westerly Jet ◽  
Sign Distribution ◽  
Subtropical Westerly Jet

The variation in tropospheric ozone over East Asia was analyzed using tropospheric column ozone data measured by the Global Ozone Monitoring Experiment (GOME) satellite. An empirical orthogonal function (EOF) analysis was carried out to derive the dominant modes of the variation in the tropospheric ozone volume-mixing ratio (TOVMR). The EOF1 mode, which explained 61.5% of the total variance, showed a same-sign distribution over all of East Asia, with a belt of enhanced ozone concentrations around 40°N. The principal component of EOF1 (PC1) suggested that photochemical ozone production together with Brewer-Dobson circulation and subtropical westerly jet plays important roles in modulating the seasonal variation of the TOVMR; ozone-rich air produced by photochemical processes was transported from the stratosphere to the troposphere by BD circulation and this ozone-rich air was then blocked by the subtropical westerly jet and accumulated north of the jet. The EOF2 mode explained 29.2% of the total variance with an opposite-sign pattern on the north and south side of 35°N. When anticyclonic circulation transported ozone-poor air from the upwelling area over the Bay of Bengal towards the Tibetan Plateau during the onset of the Asian summer monsoon, tropospheric ozone in this region decreased dramatically.

scholarly journals Distinct effects of winter monsoon and westerly circulation on dust aerosol transport over East Asia

2021 ◽  
Author(s):  
Liu Yang ◽  
Zhengguo Shi ◽  
Hui Sun ◽  
Xiaoning Xie ◽  
Xiaodong Liu ◽  
...  
Keyword(s):  
East Asia ◽  
Lower Layer ◽  
East Asian ◽  
Asian Dust ◽  
Winter Monsoon ◽  
Dust Aerosol ◽  
Tibet Plateau ◽  
Particle Sizes ◽  
Westerly Jet ◽  
Westerly Winds

Abstract The transport of dust aerosol in East Asia is affected by the East Asian winter monsoon (EAWM) and westerly circulation both for modern and geological periods. There are obvious seasonal changes in the intensity and range of EAWM and westerly jet; however, their impacts and relative contributions to East Asian dust transmission are still unclear. In this study, we use Regional Climate Model 4 (RegCM4) to simulate the changes in the East Asian dust cycle under present conditions, assessing the effects of EAWM and westerly jet on dust transport. The results show that the dust at the upper level is mainly transported by the westerly circulation, while that of the lower layer is mainly transported by the EAWM. In March, the westerly jet is located on the south side of the Tibet Plateau and the high-level dust aerosol is transmitted eastward to the northern Pacific. Low-level dust is transmitted to the southeastern China with the influence of EAWM. With the northward shift of the westerly jet, the control range of the westerly winds increases in May and their correlations are weakened. In contrary, the impact of EAWM on the lower layer dust is enhanced. Due to the strengthened interaction between the westerly winds and the EAWM, they can both affect the middle-level dust transmission. The effect of EAWM is sensitive to the dust particle sizes. Under the action of EAWM, fine-grained dust is transmitted far away, while coarse-grained dust is limited to the vicinity of the source area. Once the dust is carried to the westerly layer, the influence of westerly winds on the transmission of different particle sizes dust is similar.

scholarly journals Analysis of the East Asian Subtropical Westerly Jet Simulated by CCSR/NIES/FRCGC Coupled Climate System Model

2008 ◽  
Vol 86 (2) ◽  
pp. 257-278 ◽  
Author(s):  
Yaocun ZHANG ◽  
Masaaki TAKAHASHI ◽  
Lanli GUO
Keyword(s):  
East Asian ◽  
Climate System ◽  
System Model ◽  
Climate System Model ◽  
Westerly Jet ◽  
Subtropical Westerly Jet

scholarly journals The combined effect of two westerly jet waveguides on heavy haze in the North China Plain in November and December 2015

2019 ◽  
Author(s):  
Xiadong An ◽  
Lifang Sheng ◽  
Qian Liu ◽  
Chun Li ◽  
Yang Gao ◽  
...  
Keyword(s):  
East Asia ◽  
Rossby Wave ◽  
South China ◽  
North China Plain ◽  
North China ◽  
Combined Effect ◽  
The North ◽  
Westerly Jet ◽  
The North China Plain ◽  
Subtropical Westerly Jet

Abstract. Severe haze occurred in the North China Plain (NCP) from November to December 2015, with a wide spatial range and long duration. In this paper, the combined effect of two westerly jet waveguides on haze in the NCP was investigated based on visibility observational data and NCEP/NCAR reanalysis data. The results showed that the two Rossby waveguides within the westerly jet originating from the Mediterranean were responsible for the haze formation in the NCP. The Rossby wave propagated eastward along the subtropical westerly jet and the polar front jet, causing an anomalous anticyclone over the Sea of Japan and anticyclonic wind speed shear at 850 hPa over the NCP, which enhanced the anomalous descending air motion in the middle and lower troposphere and subsequently resulted in a stable atmosphere. Furthermore, the Rossby wave weakened the East Asia trough and Ural ridge, and strengthened the anomalous southerly wind at 850 hPa over the coastal areas of east China, decelerating the East Asia winter monsoon. The above meteorological conditions modulated haze accumulation in November and December 2015. Meanwhile, continuous rainfall related to ascending motion due to Rossby wave propagation along the subtropical westerly jet occurred in a large area of southern China. The latent heat released by rainfall acted as a heat source, inducing convection over South China. This further strengthened the ascending motion over South China so that the descending motion over the NCP was maintained, favoring the maintenance of severe haze. This study is of great significance to elucidate the formation and maintenance mechanism of large-scale haze in the NCP in late fall and boreal winter.

An assessment of the predictability of the East Asian Subtropical Westerly Jet based on TIGGE data

2015 ◽  
Vol 32 (3) ◽  
pp. 401-412 ◽  
Author(s):  
Baiquan Zhou ◽  
Ruoyun Niu ◽  
Panmao Zhai
Keyword(s):  
East Asian ◽  
Westerly Jet ◽  
Subtropical Westerly Jet

scholarly journals Zonal Extension and Retraction of the Subtropical Westerly Jet Stream and Evolution of Precipitation over East Asia and the Western Pacific

2015 ◽  
Vol 28 (17) ◽  
pp. 6783-6798 ◽  
Author(s):  
Zhiqing Xie ◽  
Yin Du ◽  
Song Yang
Keyword(s):  
East Asia ◽  
El Nino ◽  
Eastern China ◽  
Jet Stream ◽  
Seasonal Evolution ◽  
Westerly Jet ◽  
The Pacific ◽  
Anomaly Pattern ◽  
June July ◽  
Subtropical Westerly Jet

Abstract The relationship between the zonal extension and retraction of the East Asian subtropical westerly jet stream (EASWJ) and the seasonal evolution of precipitation is investigated. The EASWJ exhibits significant zonal variations associated with its seasonal evolution, which affects both large-scale atmospheric circulation and precipitation over East Asia and the North Pacific. The midlatitude rain belts and the intertropical convergence zone are located more eastward and southward during jet extensions compared to jet retractions. The seasonal cycle of the zonal variations of EASWJ can be divided into four periods: December–February, March–May, June–July, and September–November. Particularly in the mei-yu period of June–July, jet retraction events are associated with a northward shift of rain belts over eastern China, which may play an important role in the northward movement of the mei-yu rain belt to the Huaihe River valley of eastern China after 1999. The zonal extension and retraction of the jet stream are more likely to occur in the ENSO decaying phase. A composite analysis of diabatic heating and outgoing longwave radiation shows a tripolar anomaly pattern that is strongest in El Niño winter and is important for the zonal extension of the jet stream over the Pacific. This spatial structure is conducive to a strengthening local Hadley cell over the Pacific and can also appear in weak El Niño periods. On the other hand, there is no tripolar anomaly pattern for zonally retracted jet streams.

scholarly journals Contrast in the East Asian subtropical westerly jet and its association with precipitation in China between early summer and midsummer

2017 ◽  
Vol 25 (1) ◽  
pp. 119-127 ◽  
Author(s):  
Shouli Xuan ◽  
Qingyun Zhang ◽  
Shuqing Sun ◽  
Chunlin Shi
Keyword(s):  
East Asian ◽  
Early Summer ◽  
Westerly Jet ◽  
Subtropical Westerly Jet
Sign in / Sign up

Export Citation Format

Share Document