219 research outputs found

    Assimilation of FY-4A GIIRS radiance observations in the forecast of Typhoon Bavi

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    We assimilated radiance observations from the Geostationary Interferometric Infrared Sounder (GIIRS) onboard the FengYun-4A geostationary satellite to evaluate their impact on the forecast of Typhoon Bavi using WRFDA. The temperature channels with high information content, representing 90% of the information content of all temperature channels, were selected for assimilation. All radiance observations above the cloud-top were assimilated by comparing the channel height to the cloud-top height coming from the product of the Advanced Geosynchronous Radiation Imager (AGRI). The assimilation of the GIIRS observations decreased the root-mean-square error of the temperature by 2% and improved the precipitation forecast. The rain band in southeast China was reproduced well, thus showing that infrared hyperspectral radiance observations have added value in improving the circulation around typhoons and, therefore, provide better forecasts. The increased relative humidity in the upper layer and stronger typhoon outflow were found to related to the intensify of typhoon in the analysis compared with the control experiment

    Hydrological Response of Alpine Wetlands to ClimateWarming in the Eastern Tibetan Plateau

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    Alpine wetlands in the Tibetan Plateau (TP) play a crucial role in the regional hydrological cycle due to their strong influence on surface ecohydrological processes; therefore, understanding how TP wetlands respond to climate change is essential for projecting their future condition and potential vulnerability. We investigated the hydrological responses of a large TP wetland complex to recent climate change, by combining multiple satellite observations and in-situ hydro-meteorological records. We found different responses of runoff production to regional warming trends among three basins with similar climate, topography and vegetation cover but different wetland proportions. The basin with larger wetland proportion (40.1%) had a lower mean runoff coefficient (0.173 ± 0.006), and also showed increasingly lower runoff level (−3.9% year−1, p = 0.002) than the two adjacent basins. The satellite-based observations showed an increasing trend of annual non-frozen period, especially in the wetland-dominated region (2.64 day·year−1, p \u3c 0.10), and a strong extension of vegetation growing-season (0.26–0.41 day·year−1, p \u3c 0.10). Relatively strong increasing trends in evapotranspiration (ET) (~1.00 mm·year−1, p \u3c 0.01) and the vertical temperature gradient above ground surface (0.043 °C·year−1, p \u3c 0.05) in wetland-dominant areas were documented from satellite-based ET observations and weather station records. These results indicate recent surface drying and runoff reduction of alpine wetlands, and their potential vulnerability to degradation with continued climate warming

    Hexabromocyclododecanes (HBCDDs) in surface soils from coastal cities in North China:correlation between diastereoisomer profiles and industrial activities

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    Hexabromocyclododecane (HBCDD) is a brominated flame retardant with a wide range of industrial applications, although little is known about its patterns of spatial distribution in soils in relation to industrial emissions. This study has undertaken a large-scale investigation around an industrialized coastal area of China, exploring the concentrations, spatial distribution and diastereoisomer profiles of HBCDD in 188 surface soils from 21 coastal cities in North China. The detection frequency was 100% and concentrations of total HBCDD in the surface soils ranged from 0.123 to 363 ng g−1 and averaged 7.20 ng g−1, showing its ubiquitous existence at low levels. The spatial distribution of HBCDD exhibited a correlation with the location of known manufacturing facilities in Weifang, suggesting the production of HBCDD as major emission source. Diastereoisomer profiles varied in different cities. Diastereoisomer compositions in soils were compared with emissions from HBCDD industrial activities, and correlations were found between them, which has the potential for source identification. Although the contemporary concentrations of HBCDD in soils from the study were relatively low, HBCDD-containing products (expanded/extruded polystyrene insulation boards) would be a potential source after its service life, and attention needs to be paid to prioritizing large-scale waste management efforts

    Variation of adsorption effects in coals with different particle sizes induced by differences in microscopic adhesion

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    Acknowledgements This research was funded by the National Natural Science Foundation of China (grant nos. 41830427, 42130806 and 41922016), the Fundamental Research Funds for Central Universities (grant no. 2-9-2021-067) and the 2021 Graduate Innovation Fund Project of China University of Geosciences, Beijing (grant no. ZD2021YC035). We are very grateful to the reviewers and editors for their valuable comments and suggestionsPeer reviewedPostprin

    Atomic force microscopy investigation of nano-scale roughness and wettability in middle to high rank coals, with samples from Qinshui Basin, China

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    Acknowledgements This research was funded by the National Natural Science Fund (grant nos. 41830427, 42130806 and 41922016), the Fundamental Research Funds for Central Universities (grant no. 2652018002), and financial support from China Scholarship Council ((No.202006400048).Peer reviewedPostprin

    Interference mechanism in coalbed methane wells and impacts on infill adjustment for existing well patterns

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    This research was funded by the National Natural Science Foundation of China (grant nos. 41830427, 42130806 and 41922016), 2021 Graduate Innovation Fund Project of China University of Geosciences, Beijing (grant no. ZD2021YC035) and the Fundamental Research Funds for Central Universities, China (grant no. 2-9-2021-067). We are very grateful to the reviewers and editors for their valuable comments and suggestions.Peer reviewedPublisher PD
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