Aerosol direct shortwave radiative forcing effect based on SBDART model in the Pearl River Delta, Guangdong (China)

2017 ◽  
Vol 13 (1) ◽  
pp. 1 ◽  
Author(s):  
li Li ◽  
Yunpeng Wang
2021 ◽  
Vol 21 (17) ◽  
pp. 13443-13454
Author(s):  
Ifeanyichukwu C. Nduka ◽  
Chi-Yung Tam ◽  
Jianping Guo ◽  
Steve Hung Lam Yim

Abstract. This study analyzed the nature, mechanisms and drivers for hot-and-polluted episodes (HPEs) in the Pearl River Delta, China. Numerical model simulations were conducted for the summer and autumn of 2009–2011. A total of eight HPEs were identified, mainly occurring in August and September. K-means clustering was applied to group the HPEs into three clusters based on their characteristics and mechanisms. We found three HPEs were driven by weak subsidence and convection induced by approaching tropical cyclones (TC-HPE) and two HPEs were controlled by calm (stagnant) conditions (ST-HPE) with low wind speed in the lower atmosphere, whereas the remaining three HPEs were driven by the combination (hybrid) of both aforementioned systems (HY-HPE). A positive synergistic effect between the HPE and urban heat island (UHI; ∼ 1.1 ∘C increase) was observed in TC-HPE and ST-HPE, whereas no discernible synergistic effect was found in HY-HPE. Total aerosol radiative forcing (TARF) caused a reduction in temperature (0.5–1.0 ∘C) in TC-HPE and ST-HPE but an increase (0.5 ∘C) in HY-HPE.


2020 ◽  
Author(s):  
Ifeanyichukwu C. Nduka ◽  
Steve Hung Lam Yim ◽  
Chi-Yung Tam ◽  
Jianping Guo

Abstract. This study analyzed the nature, mechanisms and drivers for Hot-and-Polluted episodes (HPEs) in the Pearl River Delta, China. Numerical model simulations were conducted for summer and autumn of 2009–2011. A total of eight HPEs were identified, mainly happening in August and September. K-means clustering was applied to group the HPEs into three clusters based on their characteristics and mechanism. We found three HPEs were driven by weak subsidence and convection induced by approaching tropical cyclones (TC-HPE), two HPEs was controlled by calm conditions (ST-HPE) with low wind speed at the lower atmosphere, whereas the remaining three HPEs were driven by the combination of both aforementioned systems (HY-HPE). TC-HPE and ST-HPE had both positive synergistic effect between HPE and UHI (~1.1 °C increase); whereas no discernible synergistic effect was found in HY-HPE. Total aerosol radiative forcing (TARF) caused a reduction in temperature (0.5–1.0 °C) in TC-HPE and ST-HPE, but an increase (0.5 °C) in HY-HPE.


2010 ◽  
Vol 29 (6) ◽  
pp. 35-42
Author(s):  
Jianhua WANG ◽  
Linglong CAO ◽  
Xiaojing WANG ◽  
Xiaoqiang YANG ◽  
Jie YANG ◽  
...  

Wetlands ◽  
2021 ◽  
Vol 41 (4) ◽  
Author(s):  
Xiao-Shan Fang ◽  
Shuang Liu ◽  
Wei-Zhi Chen ◽  
Ren-Zhi Wu

AbstractThe Guangdong Xinhui National Wetland Park (GXNWP) in the Pearl River Delta is an important stopover for migratory birds in China and East Asia. Due to high levels of interference, high sensitivity and fragile environmental constraints, an efficient method to assess the health status of wetland parks such as the GXNWP is urgently needed for sustainable development. In this study, we proposed a habitat-landscape-service (HLS) conceptual model that can be used at the site scale to evaluate health status in terms of habitats, landscapes and services by considering the complex ecosystem of wetland parks. This HLS model included 28 evaluation indicators, and the indicator weights and health-grade divisions were based on expert scores using both the analytic hierarchy process (AHP) and fuzzy comprehension evaluation (FCE) methods. The results showed that the health status of the GXNWP was at the “subhealthy” level, with a membership function of 0.4643. This study found that habitat indicators (0.5715) were the key factors affecting the GXNWP health status, followed by service indicators (0.2856) and landscape indicators (0.1429). The HLS-AHP-FCE method provides a holistic health evaluation indicator system and diagnostic approach for rapidly developing wetland parks in the Pearl River Delta, China.


Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 749
Author(s):  
Yuan Gao ◽  
Zini Lai ◽  
Chao Wang ◽  
Haiyan Li ◽  
Yongzhan Mai

Water pollution can be monitored through the use of indicator species, including Brachionus calyciflorus. To do this, it is necessary to understand the species’ population ecology. Four surveys of zooplankton were conducted in May, August, and December 2018 and February 2019 in the Pearl River Delta, China, to examine the population characteristics of B. calyciflorus. The temporal and spatial distribution of abundance, biomass, dominance, and occurrence frequency were compared with those from 2012 to investigate the relationship between changes in the population of B. calyciflorus and environmental factors. The average abundance, dominance, and occurrence of B. calyciflorus in this survey were significantly higher than those of 2012 in all seasons. Principal component analysis showed that environmental factors such as the temperature, transparency, total nitrogen, and total phosphorus of water had a major impact on the abundance of B. calyciflorus. There was a significant positive correlation with transparency, total nitrogen, and total phosphorus of water, and a very significant positive correlation with water temperature. Overall, these results demonstrated that the distribution characteristics of B. calyciflorus can reflect pollution in water bodies and can be used to evaluate water quality. These research results provide a reference for evaluating China’s river health and can help to manage water quality in the Pearl River Delta.


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