Science China Earth Sciences最新文献

{"title":"Meteorological influences on co-occurrence of O₃ and PM_2.5 pollution and implication for emission reductions in Beijing-Tianjin-Hebei.","authors":"Xiaoqing Ma,&nbsp;Zhicong Yin,&nbsp;Bufan Cao,&nbsp;Huijun Wang","doi":"10.1007/s11430-022-1070-y","DOIUrl":"10.1007/s11430-022-1070-y","url":null,"abstract":"<p><p>Co-occurrence of surface ozone (O₃) and fine particulate matter (PM_2.5) pollution (CP) was frequently observed in Beijing-Tianjin-Hebei (BTH). More than 50% of CP days occurred during April-May in BTH, and the CP days reached up to 11 in two months of 2018. The PM_2.5 or O₃ concentration associated with CP was lower than but close to that in O₃ and PM_2.5 pollution, indicating compound harms during CP days with double-high concentrations of PM_2.5 and O₃. CP days were significantly facilitated by joint effects of the Rossby wave train that consisted of two centers associated with the Scandinavia pattern and one center over North China as well as a hot, wet, and stagnant environmental condition in BTH. After 2018, the number of CP days decreased sharply while the meteorological conditions did not change significantly. Therefore, changes in meteorological conditions did not really contribute to the decline of CP days in 2019 and 2020. This implies that the reduction of PM_2.5 emission has resulted in a reduction of CP days (about 11 days in 2019 and 2020). The differences in atmospheric conditions revealed here were helpful to forecast the types of air pollution on a daily to weekly time scale. The reduction in PM_2.5 emission was the main driving factor behind the absence of CP days in 2020, but the control of surface O₃ must be stricter and deeper.</p><p><strong>Electronic supplementary material: </strong>Supplementary material is available in the online version of this article at 10.1007/s11430-022-1070-y.</p>","PeriodicalId":21651,"journal":{"name":"Science China Earth Sciences","volume":" ","pages":"1-10"},"PeriodicalIF":5.7,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10205161/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9712477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Revisiting the gravity laws of inter-city mobility in megacity regions.","authors":"Pengjun Zhao,&nbsp;Haoyu Hu,&nbsp;Liangen Zeng,&nbsp;Jun Chen,&nbsp;Xinyue Ye","doi":"10.1007/s11430-022-1022-9","DOIUrl":"https://doi.org/10.1007/s11430-022-1022-9","url":null,"abstract":"<p><p>Inter-city mobility is one of the most important issues in the UN Sustainable Development Goals, as it is essential to access the regional labour market, goods and services, and to constrain the spread of infectious diseases. Although the gravity model has been proved to be an effective model to describe mobility among settlements, knowledge is still insufficient in regions where dozens of megacities interact closely and over 100 million people reside. In addition, the existing knowledge is limited to overall population mobility, while the difference in inter-city travel with different purposes is unexplored on such a large geographic scale. We revisited the gravity laws of inter-city mobility using the 2.12 billion trip chains recorded by 40.48 million mobile phone users' trajectories in the Jing-Jin-Ji Region, which contains China's capital Beijing. Firstly, unlike previous studies, we found that non-commuting rather than commuting is the dominant type of inter-city mobility (89.3%). Non-commuting travellers have a travel distance 42.3% longer than commuting travellers. Secondly, we developed more accurate gravity models for the spatial distribution of inter-city commuting and non-commuting travel. We also found that inter-city mobility has a hierarchical structure, as the distribution of inter-city travel volume follows Zipf's law. In particular, the hierarchy of non-commuting travel volume among the cities is more in line with an ideal Zipf distribution than commuting travel. Our findings contribute to new knowledge on basic inter-city mobility laws, and they have significant applications for regional policies on human mobility.</p>","PeriodicalId":21651,"journal":{"name":"Science China Earth Sciences","volume":"66 2","pages":"271-281"},"PeriodicalIF":5.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9792918/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10578557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correlation analysis between the occurrence of epidemic in ancient China and solar activity.","authors":"Si Chen,&nbsp;Yong Wei,&nbsp;Xin'an Yue,&nbsp;Kaihua Xu,&nbsp;Mingkun Li,&nbsp;Wei Lin","doi":"10.1007/s11430-022-9986-5","DOIUrl":"https://doi.org/10.1007/s11430-022-9986-5","url":null,"abstract":"<p><p>As the globe has witnessed the pandemic, epidemic diseases exert a strong impact on human beings and ecosystems. Since the Sun is the primary energy source of the Earth, some scientific pioneers attempted to search for the discernible relation between solar activity and the incidence of epidemics. In this study, the periodic changes and trends of ancient Chinese epidemic data were analyzed in comparison with those of sunspot numbers, a solar activity proxy. The results show that the epidemic and solar activity changes are in good agreement to a certain extent, especially during the Gleissberg and the de Vries cycles. The wavelet coherence shows that the frequency of the epidemic data and sunspot numbers are highly associated. In addition, results from the ensemble empirical mode decomposition illustrate consistent variations in low-frequency decompositions. This study has important implications for further understanding of the potential impact of solar activity on Earth's biosphere, the underlying mechanism of which needs further exploration.</p>","PeriodicalId":21651,"journal":{"name":"Science China Earth Sciences","volume":"66 1","pages":"161-168"},"PeriodicalIF":5.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9782271/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10559190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Observation and research of deep underground multi-physical fields-Huainan -848 m deep experiment.","authors":"Yun Wang,&nbsp;Yaxin Yang,&nbsp;Heping Sun,&nbsp;Chengliang Xie,&nbsp;Qisheng Zhang,&nbsp;Xiaoming Cui,&nbsp;Chang Chen,&nbsp;Yongsheng He,&nbsp;Qiangqiang Miao,&nbsp;Chaomin Mu,&nbsp;Lianghui Guo,&nbsp;Jiwen Teng","doi":"10.1007/s11430-022-9998-2","DOIUrl":"https://doi.org/10.1007/s11430-022-9998-2","url":null,"abstract":"<p><p>Compared with the surface, the deep environment has the advantages of allowing \"super-quiet and ultra-clean\"-geophysical field observation with low vibration noise and little electromagnetic interference, which are conducive to therealization of long-term and high-precision observation of multi-physical fields, thus enabling the solution of a series of geoscience problems. In the Panyidong Coal Mine, where there are extensive underground tunnels at the depth of 848 m belowsea level, we carried out the first deep-underground geophysical observations, including radioactivity, gravity, magnetic, magne-totelluric, background vibration and six-component seismic observations. We concluded from these measurements that (1) the background of deep subsurface gravity noise in the long-period frequency band less than 2 Hz is nearly two orders ofmagnitude weaker than that in the surface observation environment; (2) the underground electric field is obviously weaker thanthe surface electric field, and the relatively high frequency of the underground field, greater than 1 Hz, is more than two orders of magnitude weaker than that of the surface electric field; the east-west magnetic field underground is approximately the same asthat at the surface; the relatively high-frequency north-south magnetic field underground, below 10 Hz, is at least one order ofmagnitude lower than that at the surface, showing that the underground has a clean electromagnetic environment; (3) in additionto the high-frequency and single-frequency noises introduced by underground human activities, the deep underground spacehas a sig-nificantly lower background vibration noise than the surface, which is very beneficial to the detection of weakearthquake and gravity signals; and (4) the underground roadway support system built with ferromagnetic material interferesthe geomagnetic field. We also found that for deep observation in the \"ultra-quiet and ultra-clean\" environment, the existinggeophysical equipment and observation technology have problems of poor adaptability and insufficient precision as well asdata cleaning problems, such as the effective separation of the signal and noise of deep observation data. It is also urgent tointerpret and comprehensively utilize these high-precision multi-physics observation data.</p><p><strong>Electronic supplementary material: </strong>Supplementary material is available in the online version of this article at 10.1007/s11430-022-9998-2.</p>","PeriodicalId":21651,"journal":{"name":"Science China Earth Sciences","volume":"66 1","pages":"54-70"},"PeriodicalIF":5.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9782270/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10553202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geographic modeling and simulation systems for geographic research in the new era: Some thoughts on their development and construction.","authors":"Min Chen,&nbsp;Guonian Lv,&nbsp;Chenghu Zhou,&nbsp;Hui Lin,&nbsp;Zaiyang Ma,&nbsp;Songshan Yue,&nbsp;Yongning Wen,&nbsp;Fengyuan Zhang,&nbsp;Jin Wang,&nbsp;Zhiyi Zhu,&nbsp;Kai Xu,&nbsp;Yuanqing He","doi":"10.1007/s11430-020-9759-0","DOIUrl":"https://doi.org/10.1007/s11430-020-9759-0","url":null,"abstract":"<p><p>Regionality, comprehensiveness, and complexity are regarded as the basic characteristics of geography. The exploration of their core connotations is an essential way to achieve breakthroughs in geography in the new era. This paper focuses on the important method in geographic research: Geographic modeling and simulation. First, we clarify the research requirements of the said three characteristics of geography and its potential to address geo-problems in the new era. Then, the supporting capabilities of the existing geographic modeling and simulation systems for geographic research are summarized from three perspectives: Model resources, modeling processes, and operational architecture. Finally, we discern avenues for future research of geographic modeling and simulation systems for the study of regional, comprehensive and complex characteristics of geography. Based on these analyses, we propose implementation architecture of geographic modeling and simulation systems and discuss the module composition and functional realization, which could provide theoretical and technical support for geographic modeling and simulation systems to better serve the development of geography in the new era.</p>","PeriodicalId":21651,"journal":{"name":"Science China Earth Sciences","volume":"64 8","pages":"1207-1223"},"PeriodicalIF":5.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s11430-020-9759-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9222566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}