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Wang H.-B.,Jiangsu Institute of Meteorological science | Wang H.-B.,Nanjing University of Information Science and Technology | Zhang Z.-W.,Jiangsu Meteorological Service Center | Zhang L.,Lanzhou University | And 3 more authors.
Zhongguo Huanjing Kexue/China Environmental Science | Year: 2015

Angstrom exponent a is an important indicator of the size of the aerosol particles. However, a alone does not provide unambiguous information on the relative weight of coarse and fine modes because the aerosol size distribution does not meet the Junge distribution in nature. We point out that the AOD spectral curvature can provide additional information about aerosol size distributions for 0.75<α<1.7using Mie theory calculations and AERONET sun photometer data. We improved estimate of the fine mode aerosol fractions by considering the AOD spectral curvature α2. The curvatures of α2<-0.4 indicate size distributions dominated by fine mode aerosols and α2>0.3indicate size distributions dominated by coarse mode aerosols. We test and apply the graphical method of Gobbi, and discriminate different aerosol types and quantify the contribution of them. The results show that the large values of AOD mainly are caused by the dust aerosols at SACOL site. The large values of AOD are caused by the dust aerosols or the fine aerosol particles and the graphical method of Gobbi can discriminate them at Xianghe site. Data from Taihu site confirmed the site is affected by fine mode aerosols. At Taihu site, pollution hazes what generates the large aerosol loads rather than dust aerosol. ©, 2015, Zhongguo Huanjing Kexue/China Environmental Science. All right reserved. Source


Hao L.,Nanjing University of Information Science and Technology | Sun G.,U.S. Department of Agriculture | Liu Y.,U.S. Department of Agriculture | Gao Z.,Nanjing University of Information Science and Technology | And 3 more authors.
Landscape Ecology | Year: 2014

China launched the “Returning Grazing Lands to Grasslands” project about a decade ago to restore severely degraded grasslands. Grassland grazing exclusion was one of the experimental approaches for achieving the grand goal. Here, we evaluate the long-term regional ecological effects of grassland grazing exclusion in the Xilingol region of Inner Mongolia, China. The dynamics of grassland communities over 8 years (2004–2011) were continuously monitored at 11 research sites dominated by temperate steppe ecosystems. These sites represent the diverse landscapes of the Mongolian Plateau in the Arid, Semi-Arid, and Humid Climatic Zones that have varying precipitation levels. The community structure of degraded grasslands was found to recover quickly toward a benign state after grazing exclusion. The exclusion promoted an increase in mean plant community height, coverage, aboveground fresh biomass, and quality. The grasslands recovered fastest and most favorably in the Humid Zone followed by the Semi-Arid Zone and the Arid Zone. The increase in the aboveground biomass and vegetation height correlated significantly with the amount of total growing season precipitation. Precipitation therefore amplified the grazing exclusion effects on grassland restoration. Grazing exclusion was most effective in the relatively moist part of the study region. However, other factors such as global climate change and variability might have interacted with grazing management practices, thereby influencing the outcomes of grassland restoration efforts in Inner Mongolia. Future implementations of grassland ecosystem management should consider the regional climatic heterogeneity to maximize costs/benefits for achieving long-term ecosystem sustainability. © 2014, Springer Science+Business Media Dordrecht. Source


Meng L.,Chinese Academy of Meteorological Sciences | Wang C.,Chinese Academy of Meteorological Sciences | Ren Y.,Jiangsu Meteorological Service Center | Zhang J.,Northeast Normal University
Journal of Natural Disasters | Year: 2015

Based on the breeding period observation data of single-cropping rice from agricultural meteorological station records during 1981-2011 and daily meteorological data during 1961-2011, hazard spatiotemporal distribution of heat injury of single-cropping rice and its responses to climate change was analyzed using linear regression method. Results showed that: (1) Average temperature in July and August declined significantly (P<0. 05) during 1961-1993, while average temperature in May, September and October increased significantly (P < 0. 01) during the last 50 years; (2) High value area of hazard of single-cropping rice mainly concentrated in the east of Hubei Province and the west of Anhui Province, and the low value area of the hazard gradually developed to Jiangsu, Zhejiang Province and northwest of Hubei province. Heat injury occurs the most frequently in the, 1960 "s and early 21st century, with the value of hazard is highest; (3)Hazard of heat injury of single-cropping rice is positively correlated with the maximum and the average temperature in July and August (P < 0. 01), with the increase of the maximum and the average temperature, the hazard of the heat injury first increase slowly and then quickly, whose critical temperature is 31°C and 26. 5°C, respectively. Therefore, suitable seeding time and variety types should be selected according to local hazard features. Source


Zhang Z.-W.,Lanzhou University | Zhang Z.-W.,Jiangsu Meteorological Service Center | Wang H.-B.,Jiangsu Institute of Meteorological science | Zhang L.,Lanzhou University | And 4 more authors.
Zhongguo Huanjing Kexue/China Environmental Science | Year: 2014

The microphysical parameter characteristics of aerosol were analyzed at the AERONET stations located in SACOL, Xianghe and Taihu. The results showed that the annual average AOD at Xianghe and Taihu stations were 0.67±0.66 and 0.72±0.44, respectively, which were nearly 2times of the value of AOD at SACOL (0.38±0.27). The standard deviation presented a significant temporal variability. At SACOL, the higher value of AOD was found in the spring and winter, and the lower value of AOD was found in the summer and fall. However, At Xianghe and Taihu, the higher values of AOD were found in the spring and summer, and the lower values of AOD were found in the fall and winter. Combined with the size distribution, volume concentration of aerosol particles, it can be concluded that dust was the main type of aerosols at SACOL in spring. At Xianghe and Taihu stations, the types of aerosol were mainly fine mode particles in summer due to the gas-to-particle conversion process. We could observe that for the measurements with Ångström exponent (α<0.75), there was a prevalence of coarse particles, because for the lower α values, data with the fine mode volume fraction (Vf/Vt>0.4) was almost unavailable. According to analysis we could establish the limit of the fine particle predominance with α>1.7 approximately. But for 0.75<α<1.7, the range of Vf/Vt was predominantly between 0.2 and 0.8, which represented a great scattering character, hence it was not possible to establish a priori predominance for the fine or coarse particles. Source


Liu W.,U.S. Center for Disease Control and Prevention | Ji H.,U.S. Center for Disease Control and Prevention | Shan J.,U.S. Center for Disease Control and Prevention | Bao J.,Jiangsu Meteorological Service Center | And 8 more authors.
PLoS ONE | Year: 2015

Hand, foot and mouth disease (HFMD) is an important public health issue in mainland China, including Jiangsu Province. The main purpose of this study was to depict the epidemiological characteristics of HFMD and evaluate the effects of meteorological variables on its dynamics via spatiotemporal analytic methods, which is essential for formulating scientific and effective prevention and control strategies and measures. In total, 497,910 cases of HFMD occurred in the 2009-2013 period, with an average annual incidence of 126.3 per 100,000 in Jiangsu. Out of these, 87.7% were under 5 years old with a male-to-female incidence ratio of 1.4. The dominant pathogens of the laboratory-confirmed cases were EV71 and CoxA16, accounting for 44.8% and 30.6% of all cases, respectively. Two incidence peaks were observed in each year, the higher occurring between April and June, the lower between November and December. The incidence ranged between 16.8 and 233.5 per 100,000 at the county level. The incidence in the South of the province was generally higher than that in the northern regions. The most likely spatiotemporal cluster detected by space-time scan analysis occurred in May-June of 2012 in the southern region. Average temperature and rainfall were positively correlated with HFMD incidence, while the number of days with rainfall ≥ 0.1mm, low temperature, high temperature and hours of sunshine were negatively related. Particularly, relative humidity had no relationship. In conclusion, the prevalence of HFMD in Jiangsu Province has an obvious feature of seasonality. The etiological composition changed dynamically and might be a latent driving force for the temporal variation of the incidence of HFMD. A moderately warm environment promotes the transmission of the HFMD viruses, while particularly cold and hot climate conditions restrain their transmission. © 2015 Liu et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Source

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