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Role of Differences in Surface Diurnal–Nocturnal Thermodynamics over Complex Terrain in a Squall Line Process

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Journal of Meteorological Research 2019年第1期33卷 1-17页

作者： Wei TAO Xuexing QIU Ruijiao WU Kun ZHOU Anhui Meteorological observatory China Meteorological Administration

Squall lines frequently invade the Yangtze–Huaihe River region(YHR), where the complex terrain of rivers, lakes,and mountains plays an important role in the initiation and maintenance of convection. The surface heat flux not only varies with surface conditions, but also changes between day and night. Coupled with the terrain forcing, such diurnal–nocturnal thermodynamic differences shift the low-level baroclinity, and thus further complicate the convective activities. To investigate the integrated impact of diurnal–nocturnal thermodynamic differences on the development of squall lines over complex terrain including disasters that might ensue, numerical modeling experiments on a squall line in July 2014 were performed by forcing a squall line to pass the YHR separately at daytime and nighttime. The results show that the low-level instability during the day is much larger than that during the night, and is determined predominantly by the shortwave heating of the surface. Specifically, the solar radiation enhances the temperature gradient between the warmland ahead of the squall line and the convectively generated cold pool in the region around Chaohu Lake and the Yangtze River. Such low-level baroclinity sets preconditions in the environment towards the occurrence of deep convection. The increased precipitation and the evaporation of rain in the daytime also enhance the cold pool and the associated downdraft, which further intensify the squall line. Meanwhile, the valley breeze is intensified during the day. Such scenarios promote convection that extends the squall line and the associated heavy precipitation and wind gusts southward. This research may have significant implications for enhancing the squall line prediction capability in the YHR and improving our understanding of the physical mechanisms of convective activities over complex terrain.

关键词： squall line diurnal–nocturnal thermodynamic difference(DNTD) baroclinity complex terrain

令戈错湖芯重建过去17ka青藏高原大气环流变化

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科学通报 2016年第33期61卷 3583-3595页

作者：贺跃鲍征宇侯居峙 Erik T BROWN 王明达谢淑云易朝路中国地质大学地球科学学院武汉430074 中国科学院青藏高原研究所环境变化与地表过程重点实验室北京100101 large lakes observatory University of Minnesota Duluth

亚洲季风和西风作为北半球重要的大气环流系统,对青藏高原冰川进退、水量平衡及生态环境变化具有重要意义.大量研究重建了两者的强弱变化,但是末次冰消期以来,西风与亚洲季风强度变化仍然存在争议.青藏高原中部令戈错湖泊岩芯样品重建... 详细信息

亚洲季风和西风作为北半球重要的大气环流系统,对青藏高原冰川进退、水量平衡及生态环境变化具有重要意义.大量研究重建了两者的强弱变化,但是末次冰消期以来,西风与亚洲季风强度变化仍然存在争议.青藏高原中部令戈错湖泊岩芯样品重建的末次冰消期以来令戈错粒度与介形虫氧同位素记录表明,17~11.7 ka,令戈错水位较浅且波动频繁,西风是气候变化的主要影响因素,研究区环境变化与北大西洋冷事件关系密切;11.7~10ka,对应于印度季风的增强,令戈错水位迅速升高,冬季风力变小,印度季风取代西风成为控制环境变化的主要因素;10~8 ka之后,令戈错水位略有降低,可能对应于印度季风的减弱或者冰川融水的减少;8 ka之后,响应于印度季风逐渐减小,令戈错逐渐萎缩,西风可能存在增强.末次冰消期以来西风与印度季风强弱演替历史可以归纳为：16.5 ka之前,中纬度西风强盛,青藏高原大部分区域均由西风控制,与北大西洋气候变化表现出较好的耦合关系;16.5~11.5 ka气候格局与现今类似,西风控制着青藏高原中-北部地区,而青藏高原南部受印度季风影响更大.早中全新世,夏季太阳辐射增加,印度季风增强;晚全新世,印度季风减弱,西风可能对青藏高原西部以及北部存在影响.

关键词：末次冰消期粒度氧同位素印度季风西风青藏高原令戈错

Boron Isotopic Fractionation and Trace Element Incorporation in Various Species of Modern Corals in Sanya Bay, South China Sea

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Journal of Earth Science 2014年第3期25卷 431-444页

作者： Haizhen Wei Shaoyong Jiang Yingkai Xiao N Gary Hemming State Key Laboratory for Mineral Deposits Research Department of Earth Sciences Nanjing University State Key Laboratory of Geological Processes and Mineral Resources Faculty of Earth ResourcesChina University of Geosciences Wuhan Qinghai Institute of Salt lakes Chinese Academy of Sciences Lamont-Doherty Earth observatory of Columbia University Queens College School of Earth and Environmental Sciences

The boron isotope paleo-pH proxy has been extensively studied due to its potential for understanding past climate change, and further calibrations were considered for accurate applications of the proxy because of significant variability related to biocarbonate microstructure. In this work, we studied the boron isotopic fractionation between modern marine corals and their coexisting seawater collected along shallow area in Sanya Bay, South China Sea. The apparent partition coefficient of boron（KD） ranged from 0.83×10-3 to 1.69×10-3, which are in good agreement with previous studies. As the analyzed coral skeleton（~5 g） spanned the growth time period of 1–2 years, we discussed the boron isotopic fractionation between pristine corals and modern seawater using the annual mean seawater pH of 8.12 in this sea area. Without taking the vital effect into account,（11B/10B）coral values of all living corals spread over the curves of（11B/10B）borate vs.（11B/10B）sw with the α4-3 values ranging from 0.974 to 0.982. After calibrating the biological effect on the calcifying fluid pH, the field-based calcification on calcifying fluid pH（i.e., Δ（pHbiol-pHsw）） for coral species of Acropora, Pavona, Pocillopora, Faviidae, and others including Proites are 0.42, 0.33, 0.36, 0.19, respectively, and it is necessary to be validated by coral culturing experiment in the future. Correlations in B/Ca vs. Sr/Ca and B/Ca vs. pHbiol approve temperature and calcifying fluid pH influence on skeletal B/Ca. Fundamental understanding of the thermodynamic basis of the boron isotopes in marine carbonates and seawater will strengthen the confidence in the use of paleo-pH proxy as a powerful tool to monitor atmospheric CO2 variations in the past.

关键词： boron isotope paleo-pH proxy boron isotopic fractionation trace element modern coral.

EFFECT OF ENVIRONMENTAL FIELD ON TROPICAL CYCLONE TRACK AFTER LANDFALL FROM EAST CHINA SEA

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Journal of Tropical Meteorology 2006年第2期12卷 201-204页

作者：钟元余晖王东法 Zhejiang Research Institute of Meteorology Shanghai Typhoon Institute Zhejiang Meteorology observatory

The past few years have seen work on the maintenance and decaying mechanisms of tropical cyclones （TCs） over land. Statistic study has been on the landfall frequency and location of TCs and their maintenance, decaying, transition, intensification and dissipation for the past 32 years and that （1） the deeper water accumulates on land, the more favorable it would be for the maintenance of low pressures and vast lakes, and the surface of large rivers and large- sized reservoirs can slow down the decaying of TC lows, （2） the descending and intrusion of cold air from mid- and upper- tropospheric and warm advection from lower troposphere are responsible for TCs transition; and （3） after landfall, TCs tend to accelerate towards areas of intense convection to the northwest, etc. Being mainly numerical simulation and diagnostic analyses for cases covering much detail and depth, most of the studies cannot tell anything in common about how TCs maintain and decay over land. There has been little work on the difference of land track of TCs, which travel with the underlying surface changing from sea to land. The energy supply from the tropical ocean is severely reduced or completely cut off on the one hand, rough land surface is both a blocking and frictional force for TCs to dissipate their energy on the other. In fact, landfall TCs can either maintain for only a few hours and cover a distance of less than 100 km or stay active tbr more than 100 hours and go as farther away as a few thousand km inland. Why do they differ so much？ Why do TCs follow routes that differ dramatically when they land at or near the same sites with identical or similar underlying surface？ It is obvious that the environmental field is one of the essential factors for TCs after landfall. The aim of this paper is to discuss the effect of the environmental field on TCs track over land and to know whicch, synoptic systems or factors play key roles in it so as to provide basis for the forecasting of land trac

关键词： environmental field effect tropical cyclone track after landfall

Spatial and temporal distribution of storms and their activities over the Bay of Bengal

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Research in Cold and Arid Regions 2009年第5期1卷 448-457页

作者： Xu Duan Yun Tao CanQiong Cun ShiChang Guo LinYi LV Meteorological Institute of Yunnan Province Kunming Yunnan 650034 China Meteorological observatory of Dehong Prefecture in Yunnan Province Luxi Yunnan 678400 China Atmospheric Science Department of Yunnan University Kunming Yunnan 650091 China

By statistically analyzing the storm data from the Joint Typhoon Warning Center(JTWC) over the Bengal Bay during the period 1945-2006,it is found that the yearly averaged tropical cyclone(TC) number over the Bay of Bengal is 8.12,which takes place in any month of the whole year;February and March have the fewest TC *** TC numbers begin to increase starting in April and arrive at a peak in *** from TC over the Bay of Bengal,the tropical storms(TS) over the Bay of Bengal has two peak periods,appear in May and in October or November,*** regard to TS intensity,the super severe storm of H4 criterion appeared only one time during the period 1971-1986,but appeared eight times during the period *** monthly change of the original position,the averaged maintaining time,and the longest maintaining time of TS also have two peak values:They appear in April or May and in October or November,*** peak value of the original position in October or November is bigger than that in April or *** peak value of the average maintaining time and the longest main-taining time of the TS in April or May is bigger than that in October or *** landfall path is mostly moving toward northwest or west and accounts for 56.7 *** landfall path of the TS differs from that of TC in some *** main difference is that the numbers of the northwestern path and un-landfall of TS are less than those for TC,and the numbers of the western path and northeastern path of TS are greater than for *** of the landfall TS in the north-east path has a peak,it and the beginning of the rainy season in Yunnan Province are closely related;it is on Yunnan Province's early summer precipita-tion that they have a great impact.

关键词： storm over the Bay of Bengal the temporal and spatial distribution statistically characteristic TC or TS landfall

Linking microbial community analysis and ecosystem studies: A rapid lipid analysis protocol for high throughput

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Soil Ecology Letters 2019年第1期1卷 22-32页

作者： Teri C.Balser Chao Liang Jessica L.M.Gutknecht Department of Soil Science University of Wisconsin-Madison1525 Observatory DriveMadisonWI 53706USA Faculty of Science and Engineering Curtin UniversityPerthWestern Australia6845 Australia Institute of Applied Ecology Chinese Academy of SciencesShenyang 110016China Department of Soil Waterand ClimateUniversity of Minnesota439 Borlaug Hall1991 Upper Buford CircleSt.PaulMN 55108USA

During the past two decades interest in linking soil microbial community composition and activity with ecosystem scale field studies of nutrient cycling or plant community response to disturbances has *** its importance there are challenges in making this *** is the question of analytical *** general,microbiological community-level methodologies have not been readily adaptable to the large sample sizes necessary for ecosystem-scale *** a result,it has been difficult to generate compatible microbial and ecosystem data *** lipid analysis shows potential as a middle ground between simple biomass measures and molecular ***,the two protocols that have most often been followed are either rapid but indiscriminate(total lipid analysis or fatty acid methyl ester analysis;FAME),or precise but time consuming(phospholipid fatty acid analysis;PLFA).In this paper we report results from a standardized soil used test a modified extraction method(the‘hybrid’method)developed to balance the speed of FAME and the precision of PLFA in order to increase sample *** comparing the three methods,we find that FAME and PLFA are qualitatively and quantitatively *** FAME method yielded the highest fatty acid abundance,but also had high variance resulting in low *** PLFA method had precision,but low ***‘hybrid’method fell midway between FAME and PLFA for quantitative fatty acid *** addition,the hybrid extraction can be completed in a fraction of the time it takes for *** hybrid protocol appears to provide an optimal balance between effort and accuracy and therefore is a good choice for large-scale ecosystem studies.

关键词： Microbial community composition Lipid analysis PLFA MIDI-FAME Ecosystem studies

The effects of microbial activity on the geochemistry of highly acidic crater lakes: An example from Laguna Caliente, Poas volcano (Costa Rica)

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Chinese Journal Of Geochemistry 2006年第B8期25卷 228-229页

作者： Franco Tassi Orlando Vaselli Erik Fernandez Eliecer Duarte Giordano Montegrossi Angelo Minissale Department of Earth Sciences Via G. La Pira 4 50121 University of Florence Italy Volcanological and Seismological observatory National University Heredia Costa Rica CNR-Institute of Geosciences and Earth Resources Via G la Pira 4 50121 Florence Italy

From China’s Heavy Precipitation in 2020 to a “Glocal” Hydrometeorological Solution for Flood Risk Prediction

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Advances in Atmospheric Sciences 2021年第1期38卷 1-7页

作者： Huan WU Xiaomeng LI Guy J.-P.SCHUMANN Lorenzo ALFIERI Yun CHEN Hui XU Zhifang WU Hong LU Yamin HU Qiang ZHU Zhijun HUANG Weitian CHEN Ying HU Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies and School of Atmospheric SciencesSun Yat-sen UniversityGuangdong 510000China Southern Marine Science and Engineering Laboratory Guangdong 519000China Earth System Science Interdisciplinary Center University of MarylandMaryland 20742USA School of Geographical Sciences University of BristolBristol BS81THUK DFO Global Flood observatory University of Colorado BoulderBoulder 80309USA CIMA Research Foundation Savona 17100Italy National Meteorological Center Beijing 100081China Guangdong Meteorological Center GuangzhouGuangdong 510000China GuangXi Climate Center NanningGuangxi 530000China Guangdong Climate Center GuangzhouGuangdong 510000China China Three Gorges Corporation Beijing 100081China

The prolonged mei-yu/baiu system with anomalous precipitation in the year 2020 has swollen many rivers and lakes,caused flash flooding,urban flooding and landslides,and consistently wreaked havoc across large swathes of China,particularly in the Yangtze River *** precipitation and flooding anomalies have already been seen in magnitude and extension so far this year,which have been exerting much higher pressure on emergency responses in flood control and mitigation than in other years,even though a rainy season with multiple ongoing serious flood events in different provinces is not that uncommon in *** of delving into the causes of the uniqueness of this year’s extreme precipitation-flooding situation,which certainly warrants in-depth exploration,in this article we provide a short view toward a more general hydrometeorological solution to this annual nationwide problem.A“glocal”(global to local)hydrometeorological solution for floods(GHS-F)is considered to be critical for better preparedness,mitigation,and management of different types of significant precipitation-caused flooding,which happen extensively almost every year in many countries such as China,India and the United *** a GHS-F model is necessary from both scientific and operational perspectives,with the strength in providing spatially consistent flood definitions and spatially distributed flood risk classification considering the heterogeneity in vulnerability and resilience across the entire *** in the development of such a GHS-F are suggested,emphasizing the user’s requirements and needs according to practical experiences with various flood response agencies.

关键词： flooding flood risk global to local hydrological model extreme precipitation