Subseasonal characteristics and the meteorological causes of surface O3 in different East Asian summer monsoon periods over the North China Plain during 2014 - 2019

2021 ◽  
pp. 118704
Author(s):  
Libo Gao ◽  
Tijian Wang ◽  
Xuejuan Ren ◽  
Danyang Ma ◽  
Bingliang Zhuang ◽  
...  
Keyword(s):  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
North China Plain ◽  
North China ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
The North ◽  
The North China Plain ◽  
Asian Summer ◽  
Surface O3

scholarly journals Assessing Future Changes in the East Asian Summer Monsoon Using CMIP5 Coupled Models

2013 ◽  
Vol 26 (19) ◽  
pp. 7662-7675 ◽  
Author(s):  
Kyong-Hwan Seo ◽  
Jung Ok ◽  
Jun-Hyeok Son ◽  
Dong-Hyun Cha
Keyword(s):  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Moisture Flux ◽  
Moisture Convergence ◽  
Cmip5 Models ◽  
Moisture Flux Convergence ◽  
The North ◽  
Asian Summer

Abstract Future changes in the East Asian summer monsoon (EASM) are estimated from historical and Representative Concentration Pathway 6.0 (RCP6) experiments of the fifth phase of the Coupled Model Intercomparison Project (CMIP5). The historical runs show that, like the CMIP3 models, the CMIP5 models produce slightly smaller precipitation. A moisture budget analysis illustrates that this precipitation deficit is due to an underestimation in evaporation and ensuing moisture flux convergence. Of the two components of the moisture flux convergence (i.e., moisture convergence and horizontal moist advection), moisture convergence associated with mass convergence is underestimated to a greater degree. Precipitation is anticipated to increase by 10%–15% toward the end of the twenty-first century over the major monsoonal front region. A statistically significant increase is predicted to occur mostly over the Baiu region and to the north and northeast of the Korean Peninsula. This increase is attributed to an increase in evaporation and moist flux convergence (with enhanced moisture convergence contributing the most) induced by the northwestward strengthening of the North Pacific subtropical high (NPSH), a characteristic feature of the future EASM that occurred in CMIP5 simulations. Along the northern and northwestern flank of the strengthened NPSH, intensified southerly or southwesterly winds lead to the increase in moist convergence, enhancing precipitation over these areas. However, future precipitation over the East China Sea is projected to decrease. In the EASM domain, a local mechanism prevails, with increased moisture and moisture convergence leading to a greater increase in moist static energy in the lower troposphere than in the upper troposphere, reducing tropospheric stability.

scholarly journals Climatic Effects of China Large-Scale Urbanization on East Asian Summer Monsoon under Different Phases of Pacific Decadal Oscillation

Atmosphere ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 90
Author(s):  
Yongxiao Liang ◽  
Pengfeng Xiao
Keyword(s):  
Summer Monsoon ◽  
Pacific Decadal Oscillation ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Eastern China ◽  
Vertical Motion ◽  
Positive Phase ◽  
The North ◽  
Asian Summer

The effects of urbanization over eastern China on the East Asian summer monsoon (EASM) under different sea surface temperature background are compared using a Community Atmosphere Model (CAM5.1). Experiments of urbanization investigated by comparing two climate simulations with and without urban land cover under both positive and negative phases of Pacific Decadal Oscillation (PDO) show the spatial distribution of precipitation with ‘southern flood and northern drought’ and weakening status of EASM. The climate effect of urbanization in eastern China is significantly different from north to south. Anomalous vertical ascending motion due to the role of urbanization in the south of 30° N have induced an increase in convective available potential energy (CAPE) and precipitation increase over southern China. At the same time, the downward vertical motion occurs in the north of 30° N which cause warming over northern China. Due to the anti-cyclonic anomalies in the upper and lower layers of the north, the monsoon circulation is weakened which can reduce the precipitation. However, urbanization impact under various phases of PDO show different effect. In the 1956–1970 urbanization experiments of negative PDO phase, the downward vertical motion and anti-cyclonic anomalies in the north of 30° N are also weaker than that of positive phase of PDO in 1982–1996. In terms of this situation, the urbanization experiments of negative phase of PDO reveal that the range of the warming area over the north of 40° N is small, and the warming intensity is weak, but the precipitation change is more obvious compared with the background of positive phase of PDO.

scholarly journals A Lagrangian Analysis of Water Vapor Sources and Pathways for Precipitation in East China in Different Stages of the East Asian Summer Monsoon

2020 ◽  
Vol 33 (3) ◽  
pp. 977-992 ◽  
Author(s):  
Yi Shi ◽  
Zhihong Jiang ◽  
Zhengyu Liu ◽  
Laurent Li
Keyword(s):  
Water Vapor ◽  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
North China ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Seasonal Migration ◽  
East China ◽  
Terminal Stage ◽  
Asian Summer

AbstractThe Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) platform is used to simulate Lagrangian trajectories of air parcels in East China during the summer monsoon. The investigation includes four distinct stages of the East Asian summer monsoon (EASM) during its seasonal migration from south to north. Correspondingly, the main water vapor channel migrates from the west Pacific Ocean (PO) for the premonsoon in South China (SC) to the Indian Ocean (IO) for the monsoon in SC and in the Yangtze–Huaihe River basin, and finally back to the PO for the terminal stage of monsoon in North China. Further calculations permit us to determine water vapor source regions and water vapor contribution to precipitation in East China. To a large extent, moisture leading to precipitation does not come from the strongest water vapor pathways. For example, the proportions of trajectories from the IO are larger than 25% all of the time, but moisture contributions to actual precipitation are smaller than 10%. This can be explained by the large amount of water vapor lost in the pathways across moisture-losing areas such as the Indian and Indochina Peninsulas. Local water vapor recycling inside East China (EC) contributes significantly to regional precipitation, with contributions mostly over 30%, although the trajectory proportions from subregions in EC are all under 10%. This contribution rate can even exceed 55% for the terminal stage of the monsoon in North China. Such a result provides important guidance to understand the role of land surface conditions in modulating rainfall in North China.

scholarly journals Widespread air pollutants of the North China Plain during the Asian summer monsoon season: A case study

2018 ◽  
Author(s):  
Jiarui Wu ◽  
Naifang Bei ◽  
Xia Li ◽  
Junji Cao ◽  
Tian Feng ◽  
...  
Keyword(s):  
Air Quality ◽  
Summer Monsoon ◽  
North China Plain ◽  
North China ◽  
Asian Summer Monsoon ◽  
Monsoon Season ◽  
Northwest China ◽  
Summer Monsoon Season ◽  
The North ◽  
Asian Summer

Abstract. During the Asian summer monsoon season, prevailing southeasterly – southwesterly winds are subject to delivering air pollutants from the North China Plain (NCP) to the Northeast and Northwest China. In the present study, the WRF-CHEM model is used to evaluate contributions of trans-boundary transport of the NCP emissions to the air quality in the Northeast and Northwest China during a persistent air pollution episode from 22 to 28 May 2015. The WRF-CHEM model generally performs well in capturing the observed temporal variation and spatial distribution of fine particulate matters (PM2.5), ozone (O3), and NO2. The simulated temporal variation of aerosol species is also in good agreement with measurements in Beijing during the episode. Model simulations show that the NCP emissions contribute substantially to the PM2.5 level in Liaoning and Shanxi provinces, the adjacent downwind areas of the NCP, with an average of 24.2 and 13.9 μg m−3 during the episode, respectively. The PM2.5 contributions in Jilin and Shaanxi provinces are also appreciable, with an average of 9.6 and 6.5 μg m−3, respectively. The NCP emissions contribute remarkably to the O3 level in Liaoning province, with an average of 46.5 μg m−3, varying from 23.9 to 69.5 μg m−3. The O3 level in Shanxi province is also influenced considerably by the NCP emissions, with an average contribution of 35.1 μg m−3. The average O3 contributions of the NCP emissions to Jilin and Shaanxi provinces are 28.7 and 20.7 μg m−3, respectively. The effect of the NCP emissions on the air quality in Inner Mongolia is generally insignificant however. Therefore, effective mitigations of the NCP emissions not only improve the local air quality, but also are beneficial to the air quality in the Northeast and Northwest China during the Asian summer monsoon season.

scholarly journals Influence of the Summer NAO on the Spring-NAO-Based Predictability of the East Asian Summer Monsoon

2016 ◽  
Vol 55 (7) ◽  
pp. 1459-1476 ◽  
Author(s):  
Fei Zheng ◽  
Jianping Li ◽  
Yanjie Li ◽  
Sen Zhao ◽  
Difei Deng
Keyword(s):  
Summer Monsoon ◽  
North Atlantic ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Dominant Mode ◽  
The North ◽  
Secondary Role ◽  
Asian Summer ◽  
The North Atlantic

AbstractThe dominant mode of atmospheric circulation over the North Atlantic region is the North Atlantic Oscillation (NAO). The boreal spring NAO may imprint its signal on contemporaneous sea surface temperature (SST), leading to a North Atlantic SST tripolar pattern (NAST). This pattern persists into the following summer and modulates the East Asian summer monsoon (EASM). Previous studies have shown that the summer NAST is caused mainly by the preceding spring NAO, whereas the contemporaneous summer NAO plays a secondary role. The results of this study illustrate that, even if the summer NAO plays a secondary role, it may also perturb summer SST anomalies caused by the spring NAO. There are two types of perturbation caused by the summer NAO. If the spring and summer NAO patterns have the same (opposite) polarities, the summer NAST tends to be enhanced (reduced) by the summer NAO, and the correlation between the spring NAO and EASM is usually stronger (weaker). In the former (latter) case, the spring-NAO-based prediction of the EASM tends to have better (limited) skill. These results indicate that it is important to consider the evolution of the NAO when forecasting the EASM, particular when there is a clear reversal in the polarity of the NAO, because it may impair the spring-NAO-based EASM prediction.

scholarly journals Combination of Tree Rings and Other Paleoclimate Proxies to Explore the East Asian Summer Monsoon and Solar Irradiance Signals: A Case Study on the North China Plain

Atmosphere ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1180
Author(s):  
Qiang Li ◽  
Yu Liu ◽  
Ruolan Deng ◽  
Ruoshi Liu ◽  
Huiming Song ◽  
...  
Keyword(s):  
Solar Activity ◽  
Tree Ring ◽  
Tree Rings ◽  
East Asian Summer Monsoon ◽  
North China Plain ◽  
North China ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Principal Component ◽  
Asian Summer

Paleoclimate research, which involves the study of climate and environmental changes in historical and geological periods, is typically conducted using high-resolution paleoclimatic proxies, such as tree rings, historical documentations, stalagmite, and ice core. Although each paleoclimate proxy has its own merits in paleoclimatic research, reconstructions based on a single proxy may suffer from shortcomings, including insufficient reliability and low coverage of the representative area. It may be possible to overcome these shortcomings by combining multi-paleoclimatic proxies to understand paleoclimatic changes. In this study, we attempt to combine tree-ring stable oxygen isotope ratio (δ18O), tree-ring width, and stalagmite thickness data as well as historical records to establish a 320-year (1675–1994) time series using principal component analysis in the water-scarce North China Plain (NCP). The results show that the first principal component (PC1) series is closely related to regional precipitation and the maximum temperature in summer. The spatial correlation pattern indicates that the PC1 series can represent the regional hydroclimate variation not only in the NCP but also in all of northern China. The significant (p < 0.001) correlations between the PC1 series and several East Asian summer monsoon (EASM) indices prove that the PC1 reflects the intensity of the EASM. The PC1 series is consistent with the interannual variations of two reconstructed solar activity correlation indexes (r = 0.48 and 0.46, n = 320, and p < 0.001). The results indicate that the hydroclimate variation in the NCP is affected by large-scale atmospheric circulations, such as EASM and solar activity, and shows the potential of combining multiple paleoclimate proxies for analyzing regional climate change.

scholarly journals Tropospheric ozone variability during the East Asian summer monsoon as observed by satellite (IASI), aircraft (MOZAIC) and ground stations

2016 ◽  
Vol 16 (16) ◽  
pp. 10489-10500 ◽  
Author(s):  
Sarah Safieddine ◽  
Anne Boynard ◽  
Nan Hao ◽  
Fuxiang Huang ◽  
Lili Wang ◽  
...  
Keyword(s):  
Summer Monsoon ◽  
Tropospheric Ozone ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
The Other ◽  
The North ◽  
Asian Summer ◽  
Tropospheric O3 ◽  
Aircraft Data

Abstract. Satellite measurements from the thermal Infrared Atmospheric Sounding Interferometer (IASI), aircraft data from the MOZAIC/IAGOS project, as well as observations from ground-based stations, are used to assess the tropospheric ozone (O3) variability during the East Asian Summer Monsoon (EASM). Six years 2008–2013 of IASI data analysis reveals the ability of the instrument to detect the onset and the progression of the monsoon seen by a decrease in the tropospheric 0–6 km O3 column due to the EASM, and to reproduce this decrease from one year to the other. The year-to-year variability is found to be mainly dependent on meteorology. Focusing on the period of May-August 2011, taken as an example year, IASI data show clear inverse relationship between tropospheric 0–6 km O3 on one hand and meteorological parameters such as cloud cover, relative humidity and wind speed, on the other hand. Aircraft data from the MOZAIC/IAGOS project for the EASM of 2008–2013 are used to validate the IASI data and to assess the effect of the monsoon on the vertical distribution of the tropospheric O3 at different locations. Results show good agreement with a correlation coefficient of 0.73 (12 %) between the 0–6 km O3 column derived from IASI and aircraft data. IASI captures very well the inter-annual variation of tropospheric O3 observed by the aircraft data over the studied domain. Analysis of vertical profiles of the aircraft data shows a decrease in the tropospheric O3 that is more important in the free troposphere than in the boundary layer and at 10–20° N than elsewhere. Ground station data at different locations in India and China show a spatiotemporal dependence on meteorology during the monsoon, with a decrease up to 22 ppbv in Hyderabad, and up to 5 ppbv in the North China Plain.

scholarly journals Recent Intensification of the Western Pacific Subtropical High Associated with the East Asian Summer Monsoon

2015 ◽  
Vol 28 (7) ◽  
pp. 2873-2883 ◽  
Author(s):  
Shinji Matsumura ◽  
Shiori Sugimoto ◽  
Tomonori Sato
Keyword(s):  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Western Pacific Subtropical High ◽  
Western Pacific ◽  
Subtropical High ◽  
The Past ◽  
The North ◽  
Asian Summer

Abstract The summer western Pacific subtropical high (WPSH) has intensified during the past three decades. However, the underlying mechanism is not yet well understood. Here, it is shown that baiu rainband activity in midsummer, which is part of the East Asian summer monsoon, plays an important role in recent intensification in the WPSH along the baiu rainband. In contrast with the WPSH, the summer Okhotsk high, which is located to the north of the baiu rainband, has weakened during the past three decades. The north–south contrasting changes between the two highs reflect a response to northward-moved and enhanced baiu heating, which intensifies the upper-tropospheric ridge, resulting in the baroclinic intensification of the WPSH. Regional climate model experiments also support the observational analysis. Therefore, baiu convective activity in midsummer can act as a major driver for the WPSH intensification. The results here suggest that the mechanism intensifying the summer North Pacific subtropical high clearly differs between the western and eastern Pacific.

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