The primary potential source areas of O3 are in the central and southern part of Henan province, the north-western Anhui province, and the northern Shaanxi. Besides, the long-range transport analysis shows that southeast-oriented air masses are the main direction influencing summer O3 pollution. VOCs are the main precursors to the local production of O3. Conditions of high temperature, low relative humidity and low wind speed contribute to the O3 accumulation. In 2020, Yuncheng had persistent O3 pollution, with the highest concentrations in June, significantly higher than July and August. Backward trajectories, cluster analysis, potential source contribution factor (PSCF) analysis and concentration weight trajectory (CWT) analysis were also calculated using Trajstat software.
In this paper, the VOCs/NOx characteristic ratio method was used to explore the sensitivity of O3 generation. This study is based on hourly data of near-surface ozone (O3) and nitrogen oxides (NOx) and volatile organic compounds (VOCs) from June to August 2020 in Yuncheng, combined with meteorological data to analyse the characteristics of O3 pollution in summer and the influence of meteorological factors, precursors, and long-range transport on O3 pollution. Summer ozone (O3) pollution in China has become increasingly serious in recent years. Precipitation extremes are increasing, especially along the coast, with rain accumulated in the rainiest days increasing at a rate of 1‐2%/year. Every two years, there is one less frost day (TN 25☌) in the Apennines area, while there is one more tropical night (TN > 20☌) in the Adriatic coastal area. Over the period 1980‐2019, extreme values are also displaying significant trends. The cold climate types are retreating upward along the slopes of the mountain ranges. The Köppen‐Geiger climate classification is sensitive to the increase of precipitation in the recent decades, which is attributable to decreased summer precipitation overcompensated by more rain in late spring and early autumn. Precipitation (RR) decreased by ~10%/century in 1930‐2019, while it has been increasing at a rate of ~26%/century in 1980‐2019. We estimate that maximum (TX) and minimum temperature (TN) increased by ~1.6 and ~2.2☌/century, respectively, over the period 1930‐2019, while in the recent decades 1980‐2019 we found an accelerated trend of ~5.7 and ~3.9☌/century.
How to fully import 3d models into fwsim series#
The corrected time series show trends in broad agreement with external databases (CRU, Berkeley Earth, E‐OBS), and highlight the importance of relying on a local network for a better representation of gradients and variability over the territory. We process the dataset according to a preliminary ranking of stations based on data quantity and quality, and we exploit the Climatol algorithm for inhomogeneity correction.
How to fully import 3d models into fwsim portable#
Here we implement a readily portable procedure for building an upgradable long‐term homogeneous climate dataset using monthly and daily observations of temperature and precipitation over a given area of interest, exemplified here with Abruzzo, a region in Central Italy characterized by complex orography. Reliable secular time series of essential climatic variables are a fundamental element for the assessment of vulnerability, impact and adaptation to climate change. Both primary sources and secondary formation in either local or regional scale should be considered when making NPs control policies. The concentration weighted trajectory (CWT) analysis demonstrated that regional transport from provinces that surround the Yellow and Bohai Seas contributed more primary NPs to Beijing. The industry source contributed 30 % and 9 % to DNP and MDNP, respectively, which was non-negligible. By estimating the primarily emitted phenol from the ratio of phenol/CO from freshly emitted vehicle exhaust, this study proposed that oxidation of primary phenol contributes much more nitrophenol (37 %) than that from benzene oxidation ( 50 %) to the gas-phase NPs. The phenoxy radical consequently reacted with NO2, and produced nitrophenol. Phenol-OH reaction was the predominant loss pathway (46.7 %) during the heavy pollution episode, which produced phenoxy radical (C6H5O). Our results showed that secondary formation contributed 38 %, 9 %, 5 %, 17 % and almost 100 % of the ambient nitrophenol (NP), methyl-nitrophenol (MNP), dinitrophenol (DNP), methyl-dinitrophenol (MDNP or DNOC), and dimethyl-nitrophenol (DMNP). In addition, the primary sources of NPs were resolved by non-negative matrix factorization (NMF) model. A box model was applied to simulate the secondary formation process of NPs. To investigate the composition, variation, and sources of nitrated phenols (NPs) in the winter of Beijing, gas-phase NPs were measured by using a chemical ionization long time-of-flight mass spectrometer (CI-LToF-MS).