Abstract:Smog caused by atmospheric fine particulate matter (PM_2.5) pollution is closely related to local pollutant discharge and is also affected by local wind fields.This study used the urban area of Wuhan as the research object and examined the formation of river-land wind along the Yangtze River and the formation and transformation of lake-land wind along the East Lake.It was found that when the start time of the river wind and lake wind was 07:00-08:00,the maximum wind speed could reach 2 m/s.Additionally,the spring and summer river winds lasted longer than the autumn and winter seasons.The summer lake winds lasted longer than the spring.At the same time,it was found that there was a significant correlation between temperature and relative humidity near the area.The trend of humidity was generally opposite to that of temperature change,and the effect of temperature on relative humidity exhibited hysteresis with a delay time of about 1 h.

Abstract:Ambient volatile organic compounds (VOCs) were collected from July 2016 to June 2017 at a residential site in Wuhan.The characteristics and source apportionment were studied.The results showed that the total concentration of VOCs was (46.24±24.57)×10^-9;the concentration of alkanes was largest,followed by oxygenated VOCs,olefins,halogenated hydrocarbons,and aromatic hydrocarbons.Affected by motor vehicle exhaust,the ratio of alkanes was higher in the morning than in the afternoon.Vehicular exhaust was the major source in January,and the concentrations of VOCs in summer were higher than those in winter because of local coating solvents used for the chemical industry and photochemical reactions.The characteristics of biogenic emissions were clear from May to September.The positive matrix factorization model was used to investigate sources of VOCs in a residential area of Wuhan,and six factors were resolved,including combustion sources,vehicle exhaust,industrial processes,solvent use,gasoline volatilization,and biogenic sources.The contribution rate of combustion sources and vehicle exhaust was highest,which were important sources of controlled VOC emissions in the region.

Abstract:Different data (ambient air quality,ground station meteorological observation,L-band radar sounding,wind profile radar sounding,and reanalysis data) and methods (back trajectory analysis,cluster analysis,probability source concentration field (PSCF),and numerical simulation) were used in this study to investigate the effects of meteorological conditions on heavy pollution periods and to reveal the contribution of external pollutants transported by the easterly wind,which creates severe pollution days in Wuhan,China.The results of the study are as follows.1) The easterly wind containing a high concentration of PM_2.5 (tiny particles or droplets in the air that are two and a half microns or less in width)will pass through the southern part of Anhui.The model results show that the easterly and northerly airflows and local circulation play a very important role in forming a repeated pollution zone in Wuhan.Pollution in Wuhan will be aggravated because of the external pollutants transported by easterly small winds.2) The results of the PSCF method show that the main potential pollutant source areas in the autumn-winter season in Wuhan are the Anhui,Jiangsu,Shandong,Henan,Hunan,and Jiangxi provinces,and prefecture-level cities around Wuhan.Therefore,regulating regional transboundary air pollution control (especially in the southern part of Anhui province) in winter is imperative to effectively mitigate urban PM_2.5 loading over Wuhan.The conclusions of this paper will contribute to the forecast and early warning service for pollution incidents in Wuhan,and simultaneously provide a scientific basis for the government to plan and undertake joint pollution prevention and control decisions.

Abstract:Urbanization has greatly changed the nature of the urban underlying surface,which may increase the probability and intensity of haze weather.Using Landsat-7 ETM+and HJ-1A satellite multispectral remote sensing data,land use characteristics in Wuhan in 2002 and 2012 were analyzed by manual interpretation,and the land use planning map of Wuhan city was digitized and scaled.According to the typical gray haze weather process observed in Wuhan,different land types (history,present situation,and future) were simulated using the WRF-NAQPMS air quality numerical model.Simultaneously,the variations of the atmospheric wind field,temperature field,and concentration field of the main atmospheric pollutant in different situations were assessed,and the influence of the cushion on the haze weather was analyzed.The results provide a scientific basis for perfecting urban land planning and construction from the viewpoint of prevention and mitigation of gray haze weather.

Abstract:Referring to the sampling specification of the AP-42 method (USEPA,2011),137 dust samples were collected from different types of roads in 13 urban districts of Wuhan,and the associated sampling area,traffic flow,lane conditions,geographical location,surrounding environment,and meteorological data were recorded.Based on this information,the dust load of different road types was determined,and the dust emission factors and the emissions from different roads were estimated.The results show that the dust load of Wuhan is in the following order:branch road > secondary trunk road > trunk road > expressway.The average dust load is 2.396 g/m² for branch roads and 0.852 g/m² for expressways.The average dust load in distant suburban areas of Wuhan is about twice the average dust load in the main urban area.The order of road traffic dust emission factors of different types of roads is:branch road > secondary trunk road > trunk road > expressway,which is consistent with the trend of dust load.In 2016,the annual emissions of road traffic dust source TSP,PM₁₀,and PM_2.5 were 156,931.4 tons,39,868.7 tons,and 11,574.8 tons,respectively.The uncertainty of road traffic dust TSP emissions ranged from -24.7% to 31.4%,the uncertainty of PM₁₀ emissions from -31.3% to 32.9%,and the uncertainty of PM_2.5 emissions from -31.8% to 30.5%.Of these,the main road dust emissions were the largest,and the annual emissions of TSP,PM₁₀,and PM_2.5 were 64,447.1 tons,16,372.9 tons,and 4,753.4 tons,respectively.

Abstract:During January of 2018,heavy air pollution episodes occurred in central and eastern China.This study comprehensively analyzed the meteorological conditions,characteristics,and formation causes of a heavy air pollution episode during January 18-22,2018.The results showed that the hourly averaged concentration of PM_2.5 was greater than 150 μg/m³ in Wuhan.The main change in PM_2.5 was for particles less than 0.5 μm during the pollution process,winds.In addition to adverse weather conditions,motor vehicle and coal emissions were the most important causes of heavy air pollution,and regional transport from Henan,Anhui,Huanggang,and other cities affected Wuhan significantly.

Abstract:Based on the emission inventory of air pollution sources in Wuhan in 2014,and information from Planning of Urban Air Quality Compliance in Wuhan (2013-2027),SO₂,NO_x,PM₁₀,and PM_2.5 emissions can be reduced by controlling the establishment of ‘two high’ industries,managing pollution sources,eliminating backward productivity,and controlling the motor vehicle population.An environmental effect simulation was conducted by applying the Nested Air Quality Prediction Modeling System (NAQPMS).The results indicated that if the Compliance Plan was implemented as intended,the SO₂,NO_x,PM₁₀,and PM_2.5 emissions in Wuhan in 2020 will decline by 22%-66%,6%-37%,14%-40%,and 17%-46%,respectively,as compared to 2014.Thus,air quality in Wuhan will improve.However,the annual concentrations of NO₂,PM₁₀,and PM_2.5 will still not comply with the Grade Ⅱ Ambient Air Quality Standard.

Abstract:PM₁₀ and PM_2.5 from soil dust,construction dust,urban fugitive dust,catering sources,biomass combustion sources,industrial coal dust,and power plant coal dust were collected,and their carbon components,water-soluble ion components,and inorganic element components were analyzed to establish their source profiles.Studies have shown that the crustal elements Si,Ca,Al,and Fe are the main characteristic components of soil dust,among which Si is the component with the highest content and is also the marker component of soil dust.The contents of Si and Ca were higher in unorganized construction dust.Ca was regarded as an important element that distinguished unorganized construction dust from other sources,while the contents of OC and SO₄^2- in organized construction dust were higher than those in unorganized construction dust.The content of Ca in urban fugitive dust was relatively high,which indicated that urban fugitive dust was more affected by construction dust.The content of OC in the source profiles of biomass combustion sources was much higher than that of other components in the source profiles.In addition,the average contents of Cl^- and K were higher.K was the characteristic element of biomass combustion sources.

Abstract:Atmospheric PM_2.5 samples were collected by particulate matter samplers and the concentrations of water-soluble ions (F^-,Cl^-,NO₃^-,SO₄^2-,Na⁺,NH₄⁺,K⁺,Mg²⁺,and Ca²⁺) were analyzed in January 2018 in Wuhan city.The results show that NO₃^-,SO₄^2-,and NH₄⁺ are the major water-soluble inorganic ions in PM_2.5.Moreover,the correlation between PM_2.5 and water-soluble ions is significant,except for Mg²⁺ and Ca²⁺,and mobile sources play a dominant contributor role.The balance of anions and cations shows the PM_2.5 is neutral or weakly acidic.Four major back air mass trajectories and corresponding concentrations of PM_2.5 and water-soluble inorganic ions were obtained by a hybrid single-particle Lagrangian-integrated trajectory model and hierarchical clustering.The results indicate that regional transport had a considerable influence on this haze episode.

Abstract:The amounts of nine atmospheric pollutants emitted in Wuhan in 2014 were calculated by a comprehensive investigation of pollution sources and analyzing atmospheric pollutants emission factors as per the public manual and literature.A 3 km×3 km gridded emission inventory was developed based on distribution parameters such as coordinates,population,land types,and road network.The results showed that the total emissions of SO₂,NO_x,PM₁₀,PM_2.5,CO,BC,OC,VOCs,and NH₃ in Wuhan in 2014 were 103 thousand,170 thousand,163 thousand,71 thousand,631 thousand,6 thousand,4 thousand,198 thousand,and 16 thousand tons,respectively.Fuel combustion sources contributed the most to SO₂ emissions,accounting for 64% of the total.Mobile sources contributed the most to NO_x emissions,accounting for 51% to the total.The major emission sources of PM₁₀ and PM_2.5 were fugitive dust and industrial production.Industrial production also served as a major emissions contributor of CO and VOCs.BC and OC emissions were mainly attributed to mobile sources and biomass burning.NH₃ emissions mainly resulted from agricultural sources.Air pollutant emissions were typically concentrated from the Qingshan to the Xinzhou administrative regions.

Abstract:In order to solve the issue that monitoring PM_2.5 levels based on sparse ground stations is insufficient to provide PM_2.5 concentration data with broad coverage and high spatial resolutions and support regional fine particulate matter pollution prevention and control,the province of Hubei was selected as an area of research.MODIS AOD was used as the main predictor and was combined with meteorological parameters,such as temperature,relative humidity,wind speed,pressure,and normalized difference vegetation index(NDVI) data,as auxiliary predictors in a linear mixed effects model to establish the daily relationship of AOD-PM_2.5 from 2015 to 2017 in order to estimate PM_2.5 levels in the study area.The model was validated by a tenfold cross validation (CV) method.The results showed that the model performances were quite satisfactory,with cross-validated correlation coefficient values (CV R²) between the PM_2.5 estimations and observations of 2015-2017 of 0.89,0.85,and 0.88,respectively,suggesting that this method can be used to monitor regional PM_2.5 concentrations with rather high accuracy.The temporal and spatial variation characteristics were analyzed based on the observed and model-estimated PM_2.5 data and showed that distinct spatial variations of PM_2.5 concentrations existed,with high values in the east,south,and north and low values in the northwest and southeast.In addition,a declining trend of PM_2.5 concentrations in Hubei province was observed,with the annual mean values for 2015-2017 of 65.6±39.8 μg/m³,57.1±34.1 μg/m³,and 48.1±28.3 μg/m³,respectively.In terms of city,all cities showed a downward trend,except for Xianning and Suizhou,which had steady annual mean values in 2016 and 2017.

Abstract:Based on the environmental air quality monitoring data released by the Ministry of Ecology and Environment of the People's Republic of China and by using investigation and quantitative analysis methods,the overall characteristics and spatial differences of air quality in the five cities of Xi'an,Weinan,Xianyang,Tongchuan,and Baoji in the Guanzhong area were analyzed in this study.The results showed the following.(1) The particulate pollutants generally exceeded their standards significantly,with PM_2.5 and PM₁₀ exceeding the standards of 91% and 77%,respectively.(2) The air pollution has obvious seasonality,as the primary pollutants in winter are PM_2.5 and PM₁₀ and the major summer pollutant is O₃.(3) Air pollution in the Guanzhong area is affected by human activities such as topography,weather conditions and industrial emissions,heating,construction and road dust,and automobile exhaust.The air pollution has similarities and shows some differences.

Abstract:In the context of global change,a series of changes have taken place in the ecosystem.The IPCC's report on climate change shows that global warming is an indisputable fact that the overall effect of China's climate change is doing more harm than good.We must work together to address the negative effects of climate change.How biological and environmental elements of ecosystem change,and the relevant ecological phenomena and ecological processes,ecological problems and its mechanism,all need comprehensive monitoring and integrated evaluation,based on which the risk early-warning is possible through building models and establishing benchmarks.This is also the objective need of ecological damage compensation and ecological stability.Ecological factors influence and restrict regional climate characteristics,and the specific climate is reflected in the ecological process to varying degrees,resulting in different ecological effects.The nature of related problems naturally becomes the problem of coupling ecology with meteorology.Ecometeorology is a new subject which is produced under the background of the intersection and fusion of ecology and meteorology,and combines relevant disciplines and remote sensing information technology,which greatly enriches the subject connotation.Ecological meteorological monitoring and evaluation and early warning will be developing in the near future.Meanwhile,ecological research and the meteorological services will also be closely integrated.Furthermore,ecological meteorology evaluation methods tend to be more standardized.Especially,the "Internet+" concept will promote the continuous innovation and development in ecometeorology and the ecological "Internet of Things".This study has great practical significance for the "beautiful China" development and China's ecological civilization construction.

Abstract:Based on observation tests of the domestic BD sounding of ball loading,a method for the evaluation of wind measurement was established.The test results showed that the accuracy of BD wind was nearly the same as that of RS92 at ascent stage,and the consistency was in good agreement.The errors of the RS92 wind at descent stage and ascent stage were of the same magnitude.The initial part of the descent stage wind data needed to be pretreated or controlled when it was used.The error of the decline period of BD wind was generally the same as that of the RS92 at descent stage,except for the initial explosion of the ball.Essentially,it was close to the measurement requirements of WMO.Meanwhile,the rapid decline brought higher technical requirements to positioning.In addition,BD dropsonde of ball-loading could encrypt an original sounding in terms of time and optimize the existing sounding station network in terms of space,which would have better application potential.

Abstract:Based on air temperature data from 1971 to 2015,the difference in annual and seasonal air temperature variation trends between four island stations and nearby urban stations in eastern Zhejiang Province was investigated,by using linear-trend estimate,the least square methods,M-K tests,and mathematical statistics method.The effect of urbanization on the variation trends of the mean annual,maximum and minimum temperatures and the asymmetrical change of air temperature were also analyzed with the island stations as the background field.Results show that the temperatures have been in an increasing trend in recent 45 years in island stations,with linear trend rate of 0.3℃/(10 a),but the warming rate is obviously smaller than that of the urban stations.The warming intensity is strongest in spring and autumn,followed by winter,and weakest in summer,especially summer in the northern islands.The temperature increase in island stations is an abrupt change,which occurs early for mean maximum and late for mean minimum temperature.The abrupt temperature change time of city station is earlier than that of island stations,and there was no mutation occurring in the maximum temperature of city stations.Taking the island station temperature as background,results show that the urbanization has positive effect on the mean,maximum and minimum air temperature,thus speed up the warming trend at both yearly and seasonal level.