夏季长三角城市群热岛效应及其对大气边界层结构影响的数值模拟

利用WRF/Noah/UCM模拟系统对长三角地区城市群进行了2003—2007年共5个夏季的高分辨率数值模拟,研究了夏季长三角城市群热岛效应及其对大气边界层影响。开展了2组平行的积分试验,控制试验为MODIS遥感资料给出的地表特征分布,敏感性试验将长三角地区的城市表面改为农田类型,其他与控制试验完全相同。两组试验的对比分析表明城市群热岛存在明显的日变化特征,热岛效应白天向上发展较高,夜间地表热岛强度明显增强。城市热岛导致午后城市上空产生强烈的局地上升气流,从而使得低层大气以补偿流的形式向城市辐合,然而在夜间上升运动很微弱。伴随这种热力状况的日变化,大气边界层高度也存在明显的日变化,白天增高,夜间降低。同时,白天城市边界层内风速明显减小,夜间地面风速减小加剧,但夜间边界层顶风速却有所增强。另外,城市化还会导致“城市干岛”现象,且其白天强度大于夜间。     

2021年6月10日双柏MS5.1地震序列精定位及发震构造分析

1 地震背景 据中国地震台网( CENC)测定,2021年6月10日19时46分07秒,在云南省楚雄州双柏县发生MS5.1地震,震中(24.34°N,101.91°E),震源深度8 km.本次地震共造成楚雄州双柏县、玉溪市峨山县和易门县3个县5个乡镇不同程度受灾,2人受伤,直接经济总损失3440万元(引自云南省地震局关于双柏MS5.1地震灾害直接经济损失评估工作报告).     

FY-3E: The First Operational Meteorological Satellite Mission in an Early Morning Orbit

Fengyun-3 E(FY-3E),the world’s first early-morning-orbit meteorological satellite for civil use,was launched successfully at the Jiuquan Satellite Launch Center on 5 July 2021.The FY-3E satellite will fill the vacancy of the global early-morning-orbit satellite observation,working together with the FY-3C and FY-3D satellites to achieve the data coverage of early morning,morning,and afternoon orbits.The combination of these three satellites will provide global data coverage for numerical weather prediction(NWP)at 6-hour intervals,effectively improving the accuracy and time efficiency of global NWP,which is of great significance to perfect the global earth observing system.In this article,the background and meteorological requirements for the early-morning-orbit satellite are reviewed,and the specifications of the FY-3E satellite,as well as the characteristics of the onboard instrumentation for earth observations,are also introduced.In addition,the ground segment and the retrieved geophysical products are also presented.It is believed that the NWP communities will significantly benefit from an optimal temporal distribution of observations provided by the early morning,mid-morning,and afternoon satellite missions.Further benefits are expected in numerous applications such as the monitoring of severe weather/climate events,the development of improved sampling designs of the diurnal cycle for accurate climate data records,more efficient monitoring of air quality by thermal infrared remote sensing,and the quasicontinuous monitoring of the sun for space weather and climate.     

A Metallogenic Model of Gold Deposits of the Jiaodong Granite-Greenstone Belt

An analysis of trace elements and isotopic geochemistry suggest that the ore-forming materials of gold deposits in the Jiaodong granite-greenstone belt have multiple sources, especially the mantle source. Seismic wave, magnetic and gravity fields show that the crust-mantle structure and its coupling mechanism are the fundamental dynamic causes for the exchange and accumulation of materials and energy in the metallogenic system. Considering the evolution history of the structural setting, the tectono-metallogenic dynamics model of the area can be summarized as follows: (1) occurrence of the greenstone belt during the Archean-Proterozoic-the embryonic form of Au-source system; (2) stable tectonic setting in the Paleozoic-an intermittence in gold mineralization; (3) intensive activation and reformation of the greenstone belt in the Mesozoic-tectono-mineralization and tectono-diagensis; (4) posthumous structural activity in the Cenozoic-destruction of orebodies in the later stage. In the middle and late Ind     

The 2020/21 Extremely Cold Winter in China Influenced by the Synergistic Effect of La Niña and Warm Arctic

In the first half of winter 2020/21,China has experienced an extremely cold period across both northern and southern regions,with record-breaking low temperatures set in many stations of China.Meanwhile,a moderate La Ni?a event which exceeded both oceanic and atmospheric thresholds began in August 2020 and in a few months developed into its mature phase,just prior to the 2020/21 winter.In this report,the mid?high-latitude large-scale atmospheric circulation anomalies in the Northern Hemisphere,which were forced by the negative phase of Arctic Oscillation,a strengthened Siberian High,an intensified Ural High and a deepened East Asian Trough,are considered to be the direct reason for the frequent cold surges in winter 2020/21.At the same time,the synergistic effect of the warm Arctic and the cold tropical Pacific(La Ni?a)provided an indispensable background,at a hemispheric scale,to intensify the atmospheric circulation anomalies in middle-to-high latitudes.In the end,a most recent La Ni?a prediction is provided and the on-coming evolution of climate is discussed for the remaining part of the 2020/21 winter for the purpose of future decision-making and early warning.     

Uncertainty analysis of CO_2 flux components in subtropical evergreen coniferous plantation

We present an uncertainty analysis of ecological process parameters and CO2 flux components (Reco, NEE and gross ecosystem exchange (GEE)) derived from 3 years’ continuous eddy covariance meas-urements of CO2 fluxes at subtropical evergreen coniferous plantation, Qianyanzhou of ChinaFlux. Daily-differencing approach was used to analyze the random error of CO2 fluxes measurements and bootstrapping method was used to quantify the uncertainties of three CO2 flux components. In addition, we evaluated different ...     

Late Paleozoic Fluid Systems and Their Ore-forming Effects in the Yuebei Basin, Northern Guangdong, China

Based on detailed and systematic researches of the geology of ore deposits, fluid inclusions and isotope geochemistry etc., and regarding the Late Paleozoic fluid system of the Yuebei Basin as an integrated object in this paper, we have revealed the temporo-spatial evolution law of the basin＇s fluid system and discussed its ore-forming effects by simulating and analyzing the distribution of ore-forming elements, the fluid thermodynamics and dynamics of evolution processes of this basin. The results show that Late Paleozoic ore-forming fluid systems of the Yuebei Basin include four basic types as follows. （1） The sea floor volcanic-exhalation system developed during the rapid basin slip-extension stage in the Mid-Late Devonian, which affected the Dabaoshan region. It thus formed the Dabaoshan-type Cu-Pb-Zn-Fe sea floor volcanic-exhalation sedimentary deposits. （2） The compaction fluid system developed during the stable spreading and thermal subsidence-compression stage of the basin in the Mid-Late Devonian. The range of its effects extended all over the whole basin. It resulted in filling-metasomatic deposits, such as the Hongyan-type pyrite deposits and pyrite sheet within the Fankou-type Cu-Pb-Zn-S deposits. （3） The hot water circulation system of sea floor developed during the stage of basin uplifting and micro-aulacogen from the late Late Carboniferous to Middle Carboniferous. The range of its effects covered the Fankou region. It thus formed MVT deposits, such as the main orebody of the Fankou-type Pb-Zn-S deposits. （4） The gravity fluid system developed during the stage of fold uplifting and the basin closed from Middle Triassic to Jurassic, forming groundwater hydrothermal deposits, e.g. the veinlet Pb-Zn-calcite orebodies of the Fankou-type Pb-Zn- S deposits. Migration and concentration of the ore-forming fluids were constrained by the state of temporo-spatial distribution of its fluid potential. Growth faults not only converged the fluids and drove them to move upwards, but also the fluids often crossed the faults to the edges of the basin at the bottom of these faults and the lithologic interfaces, and even migrated to the basin＇s edges from top to bottom along the faults, which may be one of the basic reasons for the stratabound deposits to cluster mainly along the contemporaneous faults on the inner border of the basin. The superposed mineralization resulting from the multi-stage activity of contemporaneous faults and ore-forming fluid systems in the basin may be one of the key factors for forming superlarge ore deposits.     

赞比亚西北省索卢韦齐县铜钴多金属矿地质特征

赞比亚西北省索卢韦齐县铜钴多金属矿主要存在三种矿化类型,第一种是层控型铜矿,矿石矿物为黄铜矿、黝铜矿、辉铜矿,多呈条带状、透镜状等形态,平行黑云石英片岩和二云石英片岩的片理展布;第二种为沉积型铜矿,受到背斜和穹窿的控制,含矿岩系主要为加丹加超群(Katanga)下部罗安组(Roan)页岩、砂岩,金属矿物主要为水胆石、孔雀石、蓝铜矿,多呈星点状、浸染状、斑杂状、团块状等分布在含矿页岩、砂岩中;第三种是热液型铜矿,充填在加丹加超群及其更老的地层中,矿化类型为黄铜矿黄铁矿石英脉型,一般为小型脉状矿床。该类型矿床可与前两类矿床叠加,使矿石品位提高。     

西太平洋副热带高压对华北地区降水蒸发差的影响

采用小波相关和交叉小波变换等方法, 分析了西太平洋副热带高压脊线和北界位置变化对华北地区降水蒸发差的影响。结果表明, 2000年以来华北区南部的水资源短缺问题有所缓解, 但以北京为中心的华北区东北部仍处于持续缺水期; 华北地区降水蒸发差与副热带高压脊线及北界位置变化相关密切, 存在年际和年代际尺度的显著相关振荡, 与副热带高压脊线的年代际尺度相关凝聚性最强; 时域中年际尺度相关存在局部化特征, 年代际尺度相关具有阶段性。分析认为, 2000年以来副热带高压脊线和北界位置偏北并维持反气旋型环流, 有利于水汽向华北输送, 使得华北降水增多, 是近年来华北中南部降水蒸发差增大的主要原因; 而东亚季风减弱不利于西南气流的水汽输送, 以及蒙古高原显著增暖导致蒸发增大等因素, 使得华北东北部仍处于持续缺水期。     

Vertical Observations and Analysis of PM2.5, O3, and NOx at Beijing and Tianjin from Towers during Summer and Autumn 2006

During the period between 18 August and 22 September 2006, an ultraviolet photometric O3 analyzer, a NO-NO2-NOx chemiluminescence analyzer, and a quartz micro-oscillating-scale particle concentration analyzer were simultaneously used for monitoring at three different heights each at Beijing (325-m tower) and Tianjin (255-m tower). These towers belong to the Institute of Atmospheric Physics (IAP) of the Chinese Academy of Sciences (CAS) and to the Tianjin Municipal Meteorological Bureau, respectively. These measurements were used to continuously measure the atmospheric O3 and NOx volume-by-volume concentrations and the PM2.5 mass concentration within a vertical gradient. When combined with meteorological data and information on the variation of vertical characteristics of the various atmospheric pollutants in the two cities, analysis shows that these two cities were seriously polluted by both PM2.5 and O3 during summer and autumn. The highest daily-average concentrations of PM2.5 near the ground in Beijing and Tianjin reached 183 μg m-3 and 165 μg m-3, respectively, while the O3 concentrations reached 52 ppb and 77 ppb, and NOx concentrations reached 48 ppb and 62 ppb for these two cities, respectively. The variations in the daily-average concentrations of PM2.5 between Beijing and Tianjin were demonstrated to be consistent over time. The concentrations of PM2.5 measured in Beijing were found to be higher than those in Tianjin. However, the overall O3 concentrations near the ground in Tianjin were higher than in Beijing. NOx concentrations in Tianjin were consistently lower than in Beijing. It was also found that PM2.5 pollution in Beijings atmosphere may also be affected by the pollutants originating in and delivered from Tianjin, and that Ti