Hangzhou Meteorological Bureau

Hangzhou, China

Hangzhou Meteorological Bureau

Hangzhou, China
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Xu J.-S.,The University of Nottingham Ningbo, China | He J.,The University of Nottingham Ningbo, China | He J.,University of Nottingham | He J.,Nanjing University of Information Science and Technology | And 9 more authors.
Chemosphere | Year: 2017

To investigate the seasonal and spatial variations of ion chemistry of fine particles in Northern Zhejiang Province (NZP), China, one year-long field sampling was conducted at four representative sites (two urban, one suburb, and one rural sites) in both cities of Hangzhou and Ningbo from December 2014 to November 2015. Twelve water soluble inorganic ions (WSII) were characterized in this comprehensive study. The annual average of PM2.5 concentration in NZP as overall was 66.2 ± 37.7 μg m−3, and urban sites in NZP were observed with more severe PM2.5 pollution than the suburban and rural sites. The annual average concentration of total WSII at four sampling sites in NZP was 29.1 ± 19.9 μg m−3, dominated by SO4 2− (10.3 μg m−3), and followed by NO3 − (8.9 μg m−3), NH4 + (6.6 μg m−3), Cl− (1.3 μg m−3) and K+ (0.7 μg m−3). Among all cations, NH4 + was the predominant neutralizing ion with the highest neutralization factor (NF), while the remaining cations showed limited neutralization capacity. The highest and lowest sulfur oxidation ratio (SOR) values in this region were found in summer and winter, respectively; while the seasonal patterns for nitrogen oxidation ratio (NOR) were opposite to that of SOR. Principal component analysis (PCA) showed that the significant sources of WSII in NZP were industrial emissions, biomass burning, and formation of secondary inorganic aerosols. In addition, contribution from transboundary transport of polluted aerosols was also confirmed from the assessment through air mass backward trajectory analysis. © 2017 Elsevier Ltd

Li N.,Nanjing University of Information Science and Technology | Li N.,Chinese Academy of Meteorological Sciences | Tang G.,Tsinghua University | Zhao P.,Chinese Academy of Meteorological Sciences | And 4 more authors.
Atmospheric Research | Year: 2017

This study aims to statistically and hydrologically assess the hydrological utility of the latest Integrated Multi-satellitE Retrievals from Global Precipitation Measurement (IMERG) multi-satellite constellation over the mid-latitude Ganjiang River basin in China. The investigations are conducted at hourly and 0.1° resolutions throughout the rainy season from March 12 to September 30, 2014. Two high-quality quantitative precipitation estimation (QPE) datasets, i.e., a gauge-corrected radar mosaic QPE product (RQPE) and a highly dense network of 1200 rain gauges, are used as the reference. For the implementation of the study, first, we compare IMERG product and RQPE with rain gauge-interpolated data, respectively. The results indicate that both remote sensing products can estimate precipitation fairly well over the basin, while RQPE significantly outperforms IMERG product in almost all the studied cases. The correlation coefficients of RQPE (CC = 0.98 and CC = 0.67) are much higher than those of IMERG product (CC = 0.80 and CC = 0.33) at basin and grid scales, respectively. Then, the hydrological assessment is conducted with the Coupled Routing and Excess Storage (CREST) model under multiple parameterization scenarios, in which the model is calibrated using the rain gauge-interpolated data, RQPE, and IMERG products respectively. During the calibration period (from March 12 to May 31), the simulated streamflow based on rain gauge-interpolated data shows the highest Nash–Sutcliffe coefficient efficiency (NSCE) value (0.92), closely followed by the RQPE (NSCE = 0.84), while IMERG product performs barely acceptable (NSCE = 0.56). During the validation period (from June 1 to September 30), the three rainfall datasets are used to force the CREST model based on all the three calibrated parameter sets (i.e., nine combinations in total). RQPE outperforms rain gauge-interpolated data and IMERG product in all validation scenarios, possibly due to its advantageous capability in capturing high space-time variability of precipitation systems in the humid climate during the validation period. Overall, RQPE and rain gauge-interpolated data exhibit better performance compared with the newly available IMERG product, and RQPE is better than rain gauge-interpolated data to some extent due to the combination of both radar and rain gauge observations. IMERG-forced hourly CREST hydrologic model based on the Gauge- and RQPE-calibrated parameters performs well over Ganjiang River basin. Future studies should promote the hydrological application of RQPE datasets at global and local scales, and continuously improve IMERG algorithms. © 2016

Zhong L.,Chinese Academy of Sciences | Yang R.,Public Weather Service Center | Wen Y.,University of Oklahoma | Chen L.,National Satellite Meteorology Center | And 5 more authors.
Atmospheric Research | Year: 2017

China operational weather radar network consists of more than 200 ground-based radars (GR(s)). The lack of unified calibrators often result in poor mosaic products as well as its limitation in radar data assimilation in numerical models. In this study, radar reflectivity and precipitation vertical structures observed from space-borne TRMM (Tropical Rainfall Measurement Mission) PR (precipitation radar) and GRs are volumetrically matched and cross-evaluated. It is found that observation of GRs is basically consistent with that of PR. For their overlapping scanning regions, the GRs are often affected by the beam blockage for complex terrain. The statistics show the better agreement among S band A type (SA) radars, S band B type (SB) radars and PR, as well as poor performance of S band C type (SC) radars. The reflectivity offsets between GRs and PR depend on the reflectivity magnitudes: They are positive for weak precipitation and negative for middle and heavy precipitation, respectively. Although the GRs are quite consistent with PR for large sample, an individual GR has its own fluctuated biases monthly. When the sample number is small, the bias statistics may be determined by a single bad GR in a group. Results from this study shed lights that the space-borne precipitation radars could be used to quantitatively calibrate systematic bias existing in different GRs in order to improve the consistency of ground-based weather radar network across China, and also bears the promise to provide a robust reference even form a space and ground constellation network for the dual-frequency precipitation radars onboard the satellites anticipated in the near future. © 2017 Elsevier B.V.

Yu B.,Nanjing University of Information Science and Technology | Zhu B.,Nanjing University of Information Science and Technology | Dou J.-J.,Institute of Urban Meteorology | Zhang W.-W.,Zhejiang Meteorological Bureau | Hu D.-Y.,Hangzhou Meteorological Bureau
Zhongguo Huanjing Kexue/China Environmental Science | Year: 2017

In this paper, the seasonal atmospheric circulation patterns over Hangzhou were classified, based on the Lamb-Jenkinson weather classification method. Meanwhile, we summarized the seasonal air pollution characteristics of the typical atmospheric circulation patterns with the aid of PM2.5 dataset from the national climate station in Hangzhou. Because the uncertainty of PM2.5 levels were large under cold front synoptic condition, the pollution transport and purification characteristics were analysed in autumn and winter. The results showed that in Hangzhou, winter, dominated by anticyclone and warm zone in front of cold front, was the worst polluted season. Spring and autumn are secondary. Serious air pollution was almost impossibly occured in summer. In addition, identifying by the features of temperature variability and wind speed, we found that the weak cold front was favour of pollution transport in the conditions of negative temperature variability in 24hours within 0℃ and 2℃, or the average wind speed below 2m/s. It was conducive to purify the pollution for the strong cold front which was in the condition of negative temperature variability in 24hours larger than 4℃, or the average wind speed higher than 4m/s. © 2017, Editorial Board of China Environmental Science. All right reserved.

Qian J.,Shanxi Climate Center | Zhang X.,China Institute of Technology | Zhang J.,Shanxi Climate Center | Fan L.,Hangzhou Meteorological Bureau | Wu J.,Shanxi Province Meteorological Information Center
Acta Geographica Sinica | Year: 2010

Based on the frost date data of 52 meteorological stations over Shanxi Province from 1970 to 2009, the basic characteristics of the first and last frost dates and their changing trends were analyzed in this paper using linear trend estimation method, cumulative filter method and non-parametric statistical test method respectively, and the abrupt changing feature of the frost dates was also analyzed with Mann-Kendall method. The results show that the frost dates and frost-free period have obvious spatial and temporal changing features. Along with the latitude moving northward and the altitude rising high, the first frost appears earlier, the last frost occurs later, and the frost-free period becomes shorter. With the time changing over the past 40 years, the first frost event occurs later and the frost-free period becomes longer, while the last frost date fluctuates from year to year. For the abrupt changing feature, they all have one obvious abrupt change over the past 40 years. The abrupt change of the first frost date appears in 2000, while the abrupt changes of the last frost date and the frost-free period are detected in 1997. For the spatial distribution of their changing trend, the area in which the first frost date is postponed significantly includes the east of Jinzhong city, the north of Lüliang city, the west of Xinzhou city, the south of Yuncheng city, the northwest of Linfen city and the southern part of Datong city; the area in which the last frost date appears obviously earlier includes the east mountainous region of Jinzhong city, the eastern part of Lüliang Mountains and the western part of Xinzhou city; the area in which the frost-free period extends obviously includes the region near the Yellow River, the central-eastern part of the province and the south of Yuncheng city.

PubMed | Huzhou Hongquan Biotechnology Ltd Company, Work Safety Production Science Research Institute of Zhejiang Province, Hangzhou Meteorological Bureau and Zhejiang Academy of Agricultural Sciences
Type: | Journal: Waste management (New York, N.Y.) | Year: 2014

In traditional composting, large amounts of bulking agents must be added to reduce the moisture of pig manure, which increases the cost of composting and dilutes the N, P and K content in organic fertilizers. In this study, maggot treatment was used in composting instead of bulking agents. In experiment of selecting an optimal inoculum level for composting, the treatment of 0.5% maggot inoculum resulted in the maximum yield of late instar maggots, 11.6% (maggots weight/manure weight). The manure residue became noticeably granular by day 6 and its moisture content was below 60%, which was suitable for further composting without bulking agents. Moreover, in composting experiment with a natural compost without maggot inoculum and maggot-treated compost at 0.5% inoculum level, there were no significant differences in nutrient content between the two organic fertilizers from the two treatments (paired Students t15=1.0032, P=0.3317). Therefore, maggot culturing did not affect the characteristics of the organic fertilizer. The content of TNPK (total nitrogen+total phosphorus+total potassium) in organic fertilizer from maggot treatment was 10.72% (dry weight), which was far more than that of organic fertilizer made by conventional composting with bulking agents (about 8.0%). Dried maggots as feed meet the national standard (GB/T19164-2003) for commercial fish meal in China, which contained 55.32 1.09% protein; 1.34 0.02% methionine; 4.15 0.10% lysine. This study highlights housefly maggot-treated composting can be considered sustainable alternatives for pig manure management to achieve high-quality organic fertilizer and maggots as feed without bulking agents.

Yu B.,Hangzhou Meteorological Bureau | Pan W.-Z.,Hangzhou Meteorological Bureau | Song J.,Hangzhou Meteorological Bureau | Miao Q.-L.,Nanjing University of Information Science and Technology | And 2 more authors.
Yantu Lixue/Rock and Soil Mechanics | Year: 2012

The evidence weights model based on the weights of evidence method was applied to study the zonation of the landslide geohazards in Hangzhou. The main data sources consisted of geological maps, digital elevation model (DEM), land use data and 1905 specical cases of geohazards collected from 1930 to 2009 in Hangzhou city. The evidence factors involve heavy rain, types and structure of rock, slope, slope direction and high slope, river network and Path buffer, which were derived from maps using Arcgis spatial analysis and information extraction. The weights for each evidence map were calculated using the frequency of known landslides in the classes of causative parameters; then the probability of landslide for arbitrary grid was produced by summation of assigned weight values using Arc-WofE extended module, achieving the goal of spatial prediction for potential landslide points. The accuracy verified by the spilt-sample validation method was 88.3%. The obtained results were well coincident with the occurrence of the known landslides in the study area. It is shown that the weights of evidence method could be evaluated objectively and quantitatively for multivariate analysis, as a basis of the choice of factors for landslide geohazards zonation. So the methodology is very useful and accurate, and it is worth popularizing and applying to the risk zonation and evaluation of landslide geohazards.

Xu H.-H.,Zhejiang Meteorological Science Institute | Pu J.-J.,Zhejiang Meteorological Science Institute | He J.,The University of Nottingham Ningbo, China | Liu J.,Zhejiang Meteorological Science Institute | And 2 more authors.
Advances in Meteorology | Year: 2016

In order to understand the formation and evolution of recurrent severe haze pollution episodes in Yangtze River Delta, China, a short comparative sampling campaign was conducted at the Lin'an background monitoring station from 25 November 2013 to 14 December 2013. The characteristic concentrations of PM2.5, black carbon, CO2, CO, and CH4 have been systematically recorded at the abovementioned site. Coupled with detailed analysis of air backward trajectories, fire spot distribution surrounding the studied site and meteorological impacts, temporal trend, diurnal variation, and intercorrelation of the aforementioned species have also been comprehensively investigated throughout prehaze, haze, and posthaze periods. © 2016 Hong-Hui Xu et al.

Qi B.,Hangzhou Meteorological Bureau | Du R.-G.,Hangzhou Meteorological Bureau | Yu Z.-F.,Hangzhou Normal University | Zhou B.,Hangzhou Normal University
Zhongguo Huanjing Kexue/China Environmental Science | Year: 2014

The characteristics of aerosol optical depth (AOD) and Angstrom wavelength exponent (α) were analyzed and compared using Cimel sunphotometer data from 2011 to 2012 at national basic meteorological station in Hangzhou city of China. The results showed that the mean value of AOD500 nm and α440-870 nm were 0.86 ± 0.47 and 1.25 ± 0.23, respectively. The averaged AOD over Hangzhou had no obviously seasonal variation characteristics. It was closely related to the weather patterns and internal and external sources influence in this region. The seasonal variation of α was not distinct. Due to dust aerosol spreading from north of china, the α measured in spring was a little lower compared to other seasons. The diurnal variation of averaged AOD showed a single peak distribution with the peak value and valley value at 15:00 and 06:00 respectively. The significantly increased value of AOD in the afternoon were due to the secondary aerosols generated from photochemical reactions that caused by strongly solar radiations and the aerosols in the surface layer spreading to upper layer influenced by turbulent transfer action. Both the AOD and α showed obvious single peak of frequencies based on the frequency distribution. It was found that the AOD and α can be better characterized by a lognormal distribution. The frequency of α, occurring in the high value range between 1.1and 1.7was 77.8%, which indicated that the average effective radii of aerosol particles were small and the aerosols should be classified as urban-industrial aerosols in Hangzhou. The data also showed high AOD (> 1.0) both clustering in the fine mode growth wing and the coarse mode.

Du R.-G.,Hangzhou Meteorological Bureau | Qi B.,Hangzhou Meteorological Bureau | Zhou B.,Hangzhou Normal University | Yu Z.-F.,Hangzhou Normal University
Zhongguo Huanjing Kexue/China Environmental Science | Year: 2013

The variations of the aerosol absorption coefficient in the urban area of Hangzhou city for the period from April to June, 2011 and from December, 2011 to February 2012, were studied using black carbon and conventional meteorological date at national basic meteorological stations. The results showed that the absorption coefficient in winter [(42.3±17.7)Mm-1] was higher than that in summer [(35.8±10.5)Mm-1] and the aerosol absorption coefficient changed violently in winter. The diurnal variation of the aerosol absorption coefficient presented a double-peak on effects of boundary layer evolution and human activities, the peak value appeared at 07:00~09:00, the valley value appeared at 14:00, the second peak value appeared at 19:00~20:00. The most representative aerosol absorption coefficient was 24.7Mm-1, which was calculated by fitting hourly frequency distribution. Aerosol absorption coefficient in haze was higher than that in no-haze. The increase in haze pollution led to step up trend of aerosol absorption coefficient, which may be one of the important reasons for visibility degradation.

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