Huan Jing Ke Xue
September 2024
Based on the environmental monitoring data and meteorological observational data in Hainan Island from 2015 to 2021, the PM-polluted characteristics, influencing factors, and potential contributing regions were analyzed using the backward trajectory simulation, cluster analysis, potential source analysis function (PSCF), and concentration weight trajectory (CWT) methods. The results showed that PM in Hainan Island had an obvious seasonal variation, with the highest in winter (22.6 μg·m), followed by that in autumn and spring (17.
View Article and Find Full Text PDFThis study selected 15 key predictors of the maximum of 8-hour averaged ozone (O) concentration (O-8h), using the O concentration of Haikou and ERA5 reanalysis data from 2015 to 2020, and constructed a multiple linear regression (MLR) model, support vector machine (SVM) model, and BP neural network (BPNN) model, to predict and test the O-8h concentration of Haikou in 2021. The results showed that the absolute value of correlation coefficients between the O-8h and related key prediction factors was mainly among 0.2 and 0.
View Article and Find Full Text PDFSemicarbazide, as a derivative of urea, constitutes a great variety of functional molecules for different needs. Herein, novel stationary phases with an incorporated semicarbazide group were proposed. Using aliphatic (docosanoyl, C22) and aromatic (benzoyl, Bz) hydrazides, the semicarbazide-embedded ligands were synthesized before chemical modification of the silica gel, allowing for an accurate interpretation of the chromatographic properties of the corresponding packings.
View Article and Find Full Text PDFBased on ambient air quality data, meteorological observation data, and satellite remote sensing data, the temporal and spatial variations in ozone (O) pollution, the sensitivity of O, and its relationship with meteorological factors in Hainan Island were analyzed in this study. The results showed that the maximum daily 8-h moving mean (O-8h) in western and northern cities in Hainan Island was higher than that in the central, eastern, and southern cities. O-8h was the highest in 2015, and O-8h exceeding the standard proportion was the largest in 2019.
View Article and Find Full Text PDFBased on the 181 tropical cyclones data in the western North Pacific Ocean from 2015 to 2020, hourly ozone (O) concentration data, and meteorological observation data of 18 cities and counties in Hainan Island, this study analyzed the impacts of tropical cyclones on ozone pollution in Hainan Island. We found that 40 (22.1%) tropical cyclones experienced O pollution in Hainan Island during the lifetime of tropical cyclones in the past six years.
View Article and Find Full Text PDFHuan Jing Ke Xue
May 2023
In order to explore the influence of the 2016 typhoon Nangka on ozone (O) concentration in Hainan Island, this study employed correlation analysis and backward trajectory simulated methods, using the hourly air quality monitoring data, meteorological data, EAR5 reanalysis data, and bright temperature (TBB) infrared from the Himawari-8 satellite from October 10 to 14, 2020. The results showed that, during the typhoon process from October 11 to 13, the O-8h (maximum of 8 hours sliding average) concentration exceeded the standard. The averaged (O-8h) of Hainan Island reached its peak value (130.
View Article and Find Full Text PDFBased on the air quality and meteorological monitoring data of Hainan province in autumn of 2019, this study analyzed the characteristics and potential sources for the four O polluted processes in Hainan province, using the methods of correlation analysis, HYSPLIT backward trajectory modeling, PSCF (potential source contribution function), and CWT (concentration weighted-trajectory). The results showed that ① the average concentrations of the maximum 8h average (O-8h) for process 1 and process 3, which occurred from September 21 to 30 and November 3 to 11 with the durations of 10 d and 9 d, were 145.52 μg·m and 143.
View Article and Find Full Text PDFIn 1945 the Food and Agricultural Organization (FAO) chose its Latin motto 'fiat panis' which translates as 'let there be bread' to prevent an unprecedented health catastrophe as a result of endemic hunger and poor nutritional health. Despite the long standing effort in this regard, for so many people, especially in developing economies in sub-Saharan Africa, access to enough, good quality, and constant supply of food and water remains an affront to good nutritional health. Globally, the FAO reports that 815 million people representing 10% of the population worldwide are currently undernourished.
View Article and Find Full Text PDFThis study investigated temporal and spatial variations in O-8h (defined as the maximum 8 h average result) in Hainan Province from 2015 to 2020 and further analyzed its relationships with precursors and meteorological factors based on a dataset of observations from 32 environmental monitoring stations in Hainan. Basic statistical methods, including the empirical orthogonal function (EOF), climatic tendency rate, and climatic trend coefficient analysis, were used here. The results showed that (O-8h) was higher in northern and western Hainan than that in other regions, with the maximum value occurring in Dongfang City (91.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
January 2018
The ground observation data was used to analyze the variation of cloud amount and light precipitation over South China during 1960-2009. The total cloud cover (TCC) decreases in this period, whereas the low cloud cover (LCC) shows the obvious opposite change with increasing trends. LCP defined as low cloud cover/total cloud cover has increased, and small rainy days (< 10 mm day) decreased significantly (passing 0.
View Article and Find Full Text PDFHuan Jing Ke Xue
September 2016
The long-term observational data of sunshine duration (SD) and diffuse radiation percentage (defined as diffuse solar radiation/total solar radiation, DRP) on sunny days during 1960-2005 were analyzed in 7 urban agglomerations and the whole of China. The results show that the sunny sunshine duration (SSD) has decreased significantly except at a few stations over northwestern China in the past 46 years. An obvious decrease of the SSD is found in eastern China, with the trend coefficients lower than -0.
View Article and Find Full Text PDFThe temporal-spatial characteristics of the tropospheric column NO2 (TroNO2) and total column NO2 (TotNO2) over Hainan Island are analyzed using remote sensing data derived from OMI sensor, and also combining surface wind, SO2, HYSPLIT model to research the source of atmospheric pollutants over Hainan Island. The results show that: The value of NO2 in northern area is higher than that in southern area, and the value of NO, in central mountainous area is lower than those other places. In addition, the seasonal variation of NO2 indicates that NO2 is higher in winter and lower in summer, which can be attributed to precipitation in summer and external transport of atmospheric pollutants in winter.
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