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Aerosol-Cloud-Precipitation Interactions in WRF Model:Sensitivity to Autoconversion Parameterization

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Journal of Meteorological Research 2015年第1期29卷 72-81页

作者：解小宁刘晓东 state key laboratory of loess and Quaternary geology Institute of Earth EnvironmentChinese Academy of Sciences Department of Environmental Science and Technology School of Human Settlements and Civil EngineeringXi’an Jiaotong University

Cloud-to-rain autoconversion process is an important player in aerosol loading, cloud morphology, and precipitation variations because it can modulate cloud microphysical characteristics depending on the participation of aerosols, and affects the spatio-temporal distribution and total amount of precipitation. By applying the Kessler, the Khairoutdinov-Kogan（KK）, and the Dispersion autoconversion parameterization schemes in a set of sensitivity experiments, the indirect effects of aerosols on clouds and precipitation are investigated for a deep convective cloud system in Beijing under various aerosol concentration backgrounds from 50 to 10000 cm^-3. Numerical experiments show that aerosol-induced precipitation change is strongly dependent on autoconversion parameterization schemes. For the Kessler scheme, the average cumulative precipitation is enhanced slightly with increasing aerosols, whereas surface precipitation is reduced significantly with increasing aerosols for the KK scheme. Moreover, precipitation varies non-monotonically for the Dispersion scheme, increasing with aerosols at lower concentrations and decreasing at higher *** different trends of aerosol-induced precipitation change are mainly ascribed to differences in rain water content under these three autoconversion parameterization schemes. Therefore, this study suggests that accurate parameterization of cloud microphysical processes, particularly the cloud-to-rain autoconversion process, is needed for improving the scientific understanding of aerosol-cloud-precipitation interactions.

关键词： autoconversion parameterization aerosol-cloud-precipitation interactions numerical simulation

Characteristics of annual laminae gray level variations in a stalagmite from Shihua Cave, Beijing and its climatic significance (II)

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Science China Earth Sciences 2000年第5期43卷 521-533页

作者：秦小光谭明刘东生王先锋李铁英吕金波 laboratory of Speleothem and Paleoclimatology Institute of Geology Chinese Academy of Sciences Beijing 100029 China state key laboratory of loess and Quaternary geology Chinese Academy of Sciences Xi'an 710054 China Beijing Geological Survey Institute Beijing 102206 China

The annual laminae gray level variations in the stalagmite TS9501 of Shihua Cave, Beijing are studied in detail. The environmental factors influencing the laminae gray level are also analyzed. The following conditions may be necessary to the study on the lamina gray level. A) The seasonal differences of climate in the studied area are strong. B) The cave has a rapid and simple hydrological connection with the surface, such that the gray level variation is great; therefore, climatic changes can be more clearly recorded in a stalagmite. C) No water from other sources due to lateral flow adds to the seepage over the cave. D) There are more organic impurities than inorganic ones, whose content changes distinctly with time in the sample. By comparison with the modern instrumental climate records, it was found that the gray level of laminae is mainly related to the air temperature, especially the summer mean temperature. Therefore, the gray level can be used as a proxy of the air temperature. The variation of the lamina gray level also represents the oscillation of Indian summer monsoon as identified in the modern climate records. The variability of the temperature in Beijing area over the last 1 ka is reconstructed. The results show that there are several cold periods corresponding to historical records. An important phenomenon is noticed that the climatic pattern before about 1400AD is different from that after about 1400AD. In Beijing area, before about 1400AD, low amplitude and high frequency temperature oscillations dominated the signal. The climate pattern is warm-dry and cold-wet. After about 1400AD, both the temperature and rainfall varied synchronously, temperature oscillated strongly and the Little Ice Age occurred. The climate pattern is cold-dry and warm-wet. This transition of the climate pattern is also observed in other worldwide paleoclimatic records, demonstrating that there was a global climate event at about 1400AD.

关键词： stalagmite lamina annual gray level variations temperature.

Soil Carbon, Nitrogen and Microbial Dynamics of Pasturelands: Impacts of Grazing Intensity and Planting Systems

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Pedosphere 2014年第3期24卷 408-416页

作者： WANG Yi DUAN Wen-Xia C.TU S.WASHBURN CHENG Lei S.HU state key laboratory of loess and Quaternary geology Institute of Earth Environment Chinese Academy of Sciences Department of Plant Pathology North Carolina State University Sichuan Tourism University Department of Animal Science North Carolina State University

Management intensity critically influences the productivity and sustainability of pasture systems through modifying soil microbes, and soil carbon （C） and nutrient dynamics; however, such effects are not well understood yet ir the southeastern USA. We examined the effects of grazing intensity and grass planting system on soil C and nitrogen （N） dynamics, and microbial biomass and respiration in a long-term field experiment in Goldsboro, North Carolina, USA. A split-plot experiment was initiated in 2003 on a highly sandy soil under treatments of two grass planting systems （ryegrass rotation with sorghum-sudangrass hybrid and ryegrass seeding into a perennial bermudagrass stand） at low and high grazing densities. After 4 years of continuous treatments, soil total C and N contents across the 0 30 cm soil profile were 24.7% and 17.5% higher at the high than at the low grazing intensity, likely through promoting plant productivity and C allocation belowground as well as fecal and urinary inputs. Grass planting system effects were significant only at the low grazing intensity, with soil C, N, and microbial biomass and respiration in the top 10 cm being higher under the ryegrass/bermudagrass than under the ryegrass/sorghum-sudangrass hybrid planting systems. These results suggest that effective management could mitigate potential adverse effects of high grazing intensities on soil properties and facilitate sustainability of pastureland.

关键词： C allocation grass species microbial respiration microbial biomass pastureland sustainability plant productivity

Magnetostratigraphic dating of mammalian fossils in Junggar Basin,northwest China

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Chinese Science Bulletin 2007年第11期52卷 1526-1531页

作者： ZHANG Rui YUE LePing WANG JianQi Paleomagnetism and Geochronology laboratory SKL-LE Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China key laboratory for Continental Dynamics of Ministry of Education Department of Geology Northwest University Xi'an 710069 China state key laboratory of loess and Quaternary geology Institute of Earth Environment Chinese Academy of Sciences Xi'an 710075 China

The first detailed chronology for the late Oligocene to early Miocene continental record in northern Junggar Basin is presented,based on rock magnetic experiments and magnetostratigraphic investiga-tions of a 192 m thick mammal-bearing section in the Ulungur River area. Magnetites and hematites were identified as the main carriers for the characteristic remanent magnetization,and the resulting polarity sequence allows an unambiguous correlation to the geomagnetic polarity time scale (GPTS). Furthermore,the Tieersihabahe fauna layer occurs below the Paleocene/Neocene boundary,and the Suosuoquan fauna layer is just above the Neocene onset. Therefore,the age of the Tieersihabahe fauna and Suosuoquan fauna layers can be definitely estimated to be about 25.2 Ma and 22.5 Ma,respectively.

关键词：哺乳动物中国准葛尔盆地化石测定年龄

Climatic implications of seasonal δ13C in tree rings from Huangling of Shaanxi Province

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Chinese Science Bulletin 1996年第4期41卷 326-329页

作者：李正华刘荣谟安芷生吴祥定 state key laboratory of loess and Quaternary geology Chinese Academy of Sciences Xi' an 710054 China Institute of Geograhpy Chinese Academy of SciencesBeijing 100101China

The study on stable isotopic compositions of tree rings is playing an important role in reconstructing past climatic variations on the annual scale. Recently, a higher resolution study on seasonal variation in stable isotopic compositions of tree rings is developing. Some significant results on this aspect have been obtained, and all of them seem to respond to the moisture stress of growing season. Also, the seasonal δ 13C patterns in tree

关键词： seasonal δ13C climatic implications tree ring.

Vibration-induced acceleration of infiltration in loess

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Science China Earth Sciences 2021年第4期64卷 611-630页

作者： Jiading WANG Yuanjun XU Dengfei ZHANG Tianfeng GU state key laboratory of Continental Dynamics Department of GeologyNorthwest UniversityXi'an 710069China

Coupled effects of railway vibration, rainfall, and drying-wetting cycles contribute to new types of loess disasters such as the collapse and vibration-induced settlement of the railway subgrade, loess mass disintegration, and slope sliding,during the large-scale construction and operation of high-speed or heavy-haul railways in China. This has significant consequences for railways that require millimetre-level deformation control, seriously threatening railway operation and people's lives. Therefore, for the first time, "five vibration-induced effects" on loess subjected to vibration, water immersion, and drywetting cycles are discussed including the vibration-induced acceleration of cracking, infiltration, disintegration, sliding, and subsidence. In this paper, the vibration-induced acceleration of infiltration is discussed mainly. The response of loess to locomotive vibration along railways was determined using field sampling and data processing. The dominant frequency of locomotive vibration are 18-22 Hz and the maximum amplitude is 0.4 mm. Tests regarding the vibration-induced acceleration of the permeability were conducted on intact loess using a newly developed vibration permeability apparatus. The results reveal that the vibration accelerates the water permeability and increases the water saturation of loess. The permeability coefficient of saturated loess under vibration is ~1.5-20 times of that without vibration, reaching a maximum at a vibration frequency of 20 ***-induced infiltration tests were carried out on a loess column and the vibration-induced acceleration of water infiltration, wetting front evolution, and air outflow were analysed. The vibration-induced acceleration of infiltration strongly depends on the dry density, vibration frequency, and vibration amplitude. This pioneering work explores the mechnism of loess disasters triggered by locomotive vibration, rainfall, and drying-wetting cycles.

关键词： loess disaster Locomotive vibration Five vibration-induced effects Vibration-induced acceleration of infiltration Air escape loess landslide

Micro-particle deposition and lobar distribution of mass flow in human upper respiratory tract model

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Chinese Science Bulletin 2011年第4期56卷 380-385页

作者： HUANG JianHua ZHANG LianZhong School of Physics Nankai University Tianjin 300071 China state key laboratory of loess and Quaternary geology Institute of Earth Environment Chinese Academy of Sciences Xi'an 710075 China

A representative human upper respiratory tract model consisting of oropharyngeal and asymmetric tracheobronchial(TB) airways from the trachea(G0) to the main lobar bronchi(G2) was constructed. Laminar-to-turbulent airflow for typical inhalation modes as well as micro-particle transportation,wall deposition and mass flow to lobes was simulated using the CFX10.0 software from Ansys Inc. The numerical particle deposition efficiency of the oropharynx region and two generations(G1 and G2) of TB airways shows great agreement with the experimental data obtained from realistic casts. The particle deposition pattern indicates that inertial impaction is the primary mechanism in the human upper airway,and turbulence dispersion performs crescent influence especially for small particles. The initial positions of particles with different fates are confined to specifically concentrated zones. The particle mass distributions of five lobes are close to airflow distributions. The upper lobes receive fewer particles than lower lobes and the right middle lobe receives the least.

关键词：微观粒子呼吸道模型沉积效率质量流量 ANSYS公司人类肺航空公司

Climate and soil moisture environment during develop-ment of the fifth palaeosol in Guanzhong Plain

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Science China Earth Sciences 2008年第5期51卷 665-676页

作者： ZHAO JingBo GU Jing DU Juan College of Tourism and Environment Sciences Shaanxi Normal UniversityXi’an 710062China state key laboratory of loess and Quaternary geology Institute of Earth EnvironmentChinese Academy of SciencesXi’an 710075China

Based on weathering characteristics of the fifth palaeosol layer (S5) of four sections in Guanzhong Plain, the thickness of the weathered profile of the paleosol is determined to be greater than the ordi- nary soil, a weathered and leached loess layer thicker than 2 m. The distribution depth of the red argil- lans, the weathered and leached loess layer, Fe2O3, CaCO3 and Sr content under the S5 all indicate that the precipitation in Guanzhong Plain was over 900 mm at that time. The distribution depth of gravity water zone reached 4.2 m at least, and the soil moisture content was generally more than 20% within the range of 4.2 m. At that time there was sufficient soil moisture and no dried earth layer developed in Guanzhong Plain, suitable for the forest to develop. When this soil developed, the mean annual pre- cipitation was more than the annual soil moisture evaporation. The value of soil moisture balance was positive and the atmospheric precipitation could supply the underground water normally. Soil water was weak acidic in the middle and late stages when S5 developed in Guanzhong Plain. It was a kind of subtropical climate and even more humid and warmer than the northern edge of the subtropical climate zone in Guanzhong Plain when the S5 developed. At that time the subtropical climate was prevailing over the northern side and southern side of Qingling Mountains, showing the Mountains no longer to be the boundary between the subtropical zone and the temperate zone in China. The summer monsoon acted intensely and could go over Qingling Mountains frequently bring abundant precipitation.

关键词： Guanzhong Plain the fifth palaeosol weathering characteristics paleo-gravity water paleo-moisture content soil evaporation

Boron isotope geochemistry of Bangor Co Salt Lake(central Tibet):implications for boron origin and uneven mixing of lake water

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Acta Geochimica 2022年第5期41卷 731-740页

作者： Bin-Kai Li Mao-Yong He Hai-Zhou Ma Huai-De Cheng Lian-Min Ji Qinghai Provincial key laboratory of geology and Environment of Salt Lakes Qinghai Institute of Salt LakesChinese Academy of Sciences810008 XiningQinghaiChina state key laboratory of loess and Quaternary geology Institute of Earth EnvironmentChinese Academy of Sciences710061 Xi’anChina University of the Chinese Academy of Sciences 100049 BeijingChina

Boron is an essential,widely used,micronutrient element and is abundant in salt lakes on the Qinghai-Tibet *** origin and distribution of boron brine deposits on the Qinghai-Tibet Plateau is an important foundation for B resource formation,evolution,and enrichment,which have long been the subject of *** boron isotope system is a sensitive geochemical tracer,making it useful for eff ectively and precisely tracking a wide range of geological processes and *** study investigates the major cations,[B],andδB values of samples(lake brine,river waters,and cold spring water)from the Bangor Co Lake which is a typical salt lake rich in boron in Tibet,*** are magnitude-scale diff erences in[B]among diff erent sample types:river samples

关键词： Tibet Bangor Co salt lake Boron isotope Origin Fractionation processes