Vertical characteristics and source identification of PM_(10) in Tianjin

Ambient PM 10 （particulate matter with a diameter less than 10μm） concentrations were measured on a 255 meter tower in Tianjin,China.The samples were collected at four vertical levels （10,40,120 and 220 m）.Vertical characteristics for PM 10 samples were studied.The results showed that the concentrations of PM 10 and constituent species had a negative correlation with the sampling height.The highest concentrations of PM 10 and species were obtained at the 10 m level,and the lowest concentrations were measured at the 220 m level.For the fractions of species to total mass,SO 4 2- and NO 3- had higher values （fraction） at greater height;while Ca had a higher fraction at lower height.Possible source categories for the PM 10 ambient dataset were identified by the principal component analysis method.The possible source categories included crustal dust,vehicles,cement dust,and incineration as well as secondary sulfate and nitrate sources.Analysis of meteorological factors on PM 10 concentrations indicated that wind speed and inversion may be the main factors contributing to different concentrations of PM 10 at different heights.

Vertical characteristics of the Hani terrace paddyfield ecosystem in Yunnan,China

The Hani terrace paddyfield in Yunnan Province,China is categorized as a‘constructed wetland’under the Lamsar Convention classification.The Hani terrace paddyfield ranges from an altitude of 144 to 2000 m above sea level(ASL)in the southern slopes of the Ailao Mountains,angling down at a range of 15°to 75°.In this study,we investigated the ecosystem of the terrace paddyfields in the Mengpin and Quanfuzhuang administrative villages located at the center of the cultural heritage conservation district in the Hani terrace paddy-field.The Hani terrace paddyfield ecosystem structure is"forest-village-terrace paddyfield-river"in the order of descending altitude.Soil and water samples were sequen-tially taken from forests,villages and the terrace paddy-fields to be able to study the vertical characteristics of Hani’s terrace paddyfields.PO_(4)-P and NH_(3)-N in water were measured to test for water contamination.Seven soil nutrient factors were tested,including organic material(OM),char and nitrogen ratio(C/N),pH,total nitrogen(TN),total phosphorus(TP),available phosphorus(AP),and available potassium(AK).Soil quality was also eval-uated using the characteristics of the soil nutrient factors.Vertical changes in the landscape,wetland types,wetland plants,hydrology and soil nutrients were characterized.Results showed that:(1)Hani’s terrace paddyfield can be divided into five types of wetlands;the rice varieties and cultivation patterns vary in each type of wetland.(2)Hani’s terrace paddyfield has a great capacity for water conservation and a strong ability to purify contaminants.The impoundage of Hani’s terrace paddyfield is about 5050 m^(3)/hm^(2).Contaminants in the terrace paddyfield soils decrease exponentially with the decline in altitude.(3)Comparison of soil quality in five different land use types indicates decreasing soil quality from forest to terrace land to terrace paddyfield to water source.Except for headwater soil,single factors such as OM,TN and TP,and the comprehensive soil quality in individual sampling zones tend to increase with altitude elevation.Comprehensive soil quality in the Quanfuzhuang sampling zone is better than in the Mengpin sampling zone.Finally,a comparison of Hani’s terrace paddyfield with plain paddyfields and natural wetlands highlighted the vertical characteristics of Hani’s terrace paddyfield.

Can differences in the background characteristics of the chairperson-CEO vertical dyad reduce management agency costs?——A perspective Based on the internal configuration of the top management team

We test whether differences in the background characteristics of firms’chairperson and CEO can reduce management agency costs.We find that when the chairperson is older,has a higher level of education,and has more overseas experience than the CEO,the management agency costs will be lower.A series of robustness tests do not change our conclusions.In further analysis,we find that the negative relationship between the two is more significant for SOEs or firms experiencing fierce market competition.Finally,we also find that the chairman-CEO’s vertical dyad background characteristics differences can help to improve firm performance.Our study provides theoretical and practical implications for companies on how to best configure their top management team.

南京冬季浓雾的边界层特征与数值模拟分析(英文)

Based on the boundary layer data of winter dense fog in 2007 from Nanjing University of Information Science & Technology,the profile characteristics of temperature,wind direction,wind speed and humidity in a dense fog weather on December 13-14 in 2007 were analyzed,as well as their evolution laws in the formation and dispersion of fog,and the boundary layer characteristics of winter dense fog in Nanjing were revealed,while the development of fog was simulated by means of mesoscale numerical model.The results showed that the formation and dispersion of fog was greatly affected by inversion and humidity in the surface layer,and the wind direction in the surface layer also had effect on the formation and dispersion of advection fog.Mesoscale numerical model could preferably simulate the evolution of temperature,humidity,vertical speed in the development of fog,and the simulation of water vapor content in the fog could forecast the formation and dispersion of fog.

Variations and drivers of aerosol vertical characterization after clean air policy in China based on 7-years consecutive observations

Understanding the aerosol vertical characterization is of great importance to both climate and atmospheric environment. This study investigated the variations of aerosol profiles over eight regions of interest in China after clean air policy(2013-2019) and discussed the drivers of the vertical aerosol structure, using observations from active satellite measurements(CALIPSO). From the annual variation, the amplitude of extinction coefficient profiles showed a decreasing trend with fluctuations, and the maximum was 0.21 km-1in BeijingTianjin-Hebei(JJJ). For regions suffered from air pollution, the variation was greatest below 0.45 km, while it was between 1-1.5 km for Sichuan Basin. The correlation coefficient between the relative humidity(RH) and the extinction coefficient indicated that the increase of RH inhibited the decrease of the extinction coefficient in the Yangtze River Delta. In most regions, the main aerosol subtypes were polluted dust and polluted continental, but they were coarser in JJJ and North West. The frequency of concurrency of dust and polluted dust aerosols decreased in JJJ, but polluted continental aerosols occurred more frequently. Further, the aerosol extinction coefficient profiles under different pollution conditions showed that it changed most during heavy pollution periods in JJJ, especially in 2017, with a significant aerosol loading between700 and 1200 m. The atmospheric reanalysis data revealed that the weak convergence at low level and the divergence at high level supported the upward transport of aerosols in 2017. Overall, the differences in divergence allocation, RH, and wind filed were the main meteorological drivers.

Spatial–temporal characteristics of haze and vertical distribution of aerosols over the Yangtze River Delta of China

Variation of haze events occurred in the Yangtze River Delta（YRD） of China, the characteristics of meteorological elements and the vertical distribution of aerosols during haze episodes were analyzed by utilizing data of ground observation, radiosonde and CALIPSO. The results illustrate that the frequency of haze events between 1981 and 2010 peaked in winter but bottomed out in summer and decreased from north to south in the YRD region, reaching at the lowest point in ＂low frequency center＂ - Shanghai. When haze happened, the most seriously affected area was 2-4 km above the ground and the concentrated range of total backscattering coefficient（TBC） that decreased with altitude was 0.8 × 10^（-3）-2.5 × 10^（-3） km^（-1）·sr^（-1）. Particulate depolarization ratio（PDR） was less than 40%in a large part and 93% aerosols over the YRD area were regular particles, while the irregular ones concentrated on 2 km above the surface and the irregularity rose up but the diversity diminished when altitude increased. Color ratio（CR） was lower than 1.2 mostly at all altitudes and distributed asymmetrically above the ground. Nearly 80% aerosols under10 km were fine particles（CR 〈1.0） clustered at 2-4 km. Large particles（CR 〉 1.2） aggregated in lower troposphere massively yet relatively smaller ones gathered in middle and upper troposphere. In the YRD region, aerosols with more powerful capabilities were wider and less regular than the ones of Northwestern China.

Research on vertical spatial characteristic of satellite infrared hyperspectral atmospheric sounding data

Spatial characteristic is an important indicator of remote sensor performance,and space-borne infrared hyperspectral sounder is the frontier of atmospheric vertical sounding technology.In this paper,the formation mechanism of the vertical spatial characteristics involved in the space-borne infrared hyperspectral sounding data are analyzed in detail,which shows that the vertical spatial characteristics of sounding data depends not only on the spectral channels and their waveband coverage,but also the specific atmospheric parameter and its specific variation interested.The indicators of vertical spatial characteristics are defined and their mathematical models are established based on the mechanism analyses.These models are applied to the vertical spatial characteristic evaluation of atmospheric temperature sounding for FY-4A GIIRS,which is the first space-borne infrared hyperspectral atmospheric sounder in geostationary orbit.It is concluded that FY-4A GIIRS can sound the vertical temperature distribution in whole troposphere and lower stratosphere with height<35 km.This study can provide basic information to support the improvement of infrared hyperspectral sounder and the trace of vertical spatial characteristics of atmospheric inversion products.