气候系统对CO2强迫和太阳辐射强迫在不同时间尺度的响应

使用HadCM3L气候模式,针对突然增加的4倍CO₂浓度和增加4%的太阳辐射强迫进行一系列理想化模拟试验,分析并比较了CO₂强迫和太阳辐射强迫对气候系统的影响机制和异同。模拟结果表明,突然增加的4倍CO₂浓度和增加4%的太阳辐射造成的长期全球表面平均温度变化基本相同,但二者造成降水的变化差异很大。气候系统对CO₂和太阳辐射的响应可以分为快响应和慢响应两个部分,而降水的差异主要体现在大约1个月时间尺度内的快响应阶段,在这一时间段,陆地区域CO₂的气孔效应减少了植被的蒸腾作用,导致降水受到抑制;海洋区域CO₂的辐射效应会首先导致大气长波吸收增强,而海洋的比热较大,所以海表温度变化落后于低层大气,低层大气的垂直稳定度增加,海表向上蒸发受到抑制。此外,比较不同时间尺度上CO₂对气候系统的影响,可以发现在1个月的短时间尺度上,对陆地而言,CO₂的气孔效应对气候系统的影响占主导地位,但在数年以上更长的时间尺度上,CO₂的辐射效应是导致地气系统温度升高的主要原因。     

Sulfur dioxide in rain clouds: Gas-liquid scavenging efficiencies and wet deposition rates in the presence of formaldehyde

The interaction of formaldehyde with SO₂ dissolved in the aqueous phase of clouds leads to the formation of hydroxymethane sulfonate. The impact of this process upon the gas-liquid equilibrium distribution of SO₂ in rain clouds and the ensuing wet SO₂ precipitation rate is explored. Model vertical SO₂ distributions are derived from observational data for three atmospheric regions: continental polluted, continental remote, and marine. The wet deposition rate for SO₂ in the polluted atmosphere increases by about a factor of two in the presence of formaldehyde compared with its absence. The effect is much stronger in the remote atmosphere leading to a potentially significant enhancement of wet SO₂ deposition. In the marine atmosphere, wet deposition of SO₂ may contribute as much as 35% to the total removal rate for SO₂ by all processes including dry deposition and chemical conversion to sulfate.     

Sulfur distribution and transport studies in East Asia using eulerian model

A three-dimensional regional Eulerian model of sulfur deposition and transport is developed. Processes treated in the model include emission, transport, diffusion, gas-phase and aqueous-phase chemical process, dry deposition, rainout and washout or sulfur. A “looking up table” method is provided to deal with the gas-phase chemical process including sulfur transfer. Dry-depositon velocity considers the influence of underlying surface, wind, degree of stabil-ity by parameterization. Model calculated values reasonably agrees with observation. Distribution of sulfur deposi-tion and transport in East Asia are also analyzed in this paper. Some amount of sulfur emission of different countries transport across boundaries, but the main origin of sulfur deposition in each country in East Asia is from itself. Furthermore, some transport paths on different layers and outlet or inlet zones are found. According to sulfur bal?ance and budget we concluded that sulfur outlets are bigger than inlets across boundary and emissions are more than deposition in most places of East Asia.     

世界排放大国CO2排放和GDP的格兰杰因果分析及其对国际气候治理的影响和意义

基于1990—2015年世界前20个排放大国碳排放量和国内生产总值（GDP）的时间序列数据,采用协整分析、格兰杰因果检验,对主要排放大国碳排放与经济增长之间的关系进行了实证分析。通过协整分析得出大多数国家的碳排放量与经济增长之间存在长期均衡关系;碳排放量和GDP的格兰杰检验结果显示,大多数世界排放大国碳排放与经济增长之间存在单向因果关系。发达国家主要表现为经济增长是碳排放的格兰杰原因,发展中国家则主要表现为碳排放是经济增长的格兰杰原因。研究结果反映了发达国家和发展中国家在碳减排问题上的阶段性特征,碳减排对发展中国家经济发展的负面影响明显大于发达国家。基于格兰杰因果分析结果,国际气候治理进程中关于要求发展中国家现阶段提出大幅减排目标的诉求不符合发展中国家发展阶段特征,可能影响发展中国家经济发展的正常秩序和规律。发达国家基于历史排放责任、发展阶段和能力,都应该带头开展减排行动,并帮助发展中国家实现转型、升级发展,降低经济发展对碳排放的依赖。国际气候治理需要根据并考虑不同国家的发展需求和特征,形成国际合作制度安排,实现社会经济发展与全球气候治理的协同。     

榴辉岩中金红石物相二氧化钛含量测定的不确定度评定

通过对榴辉岩中金红石物相二氧化钛含量重复测定，建立数学模型，分析了测量过程的不确定度主要来源于样品制备的不确定度、标准物质引入的不确定度、曲线拟合中产生的不确定度．以及重复试验的不确定度。当二氧化钛平均含量为3．75％时，评定其扩展不确定度为0.16％。     

湖南黄沙坪W-Mo-Bi-Pb-Zn多金属矿床硫铅同位素地球化学研究

湖南黄沙坪W-Mo-Bi-Pb-Zn多金属矿床规模大、矿种多、范围小、分带明显,是南岭有色金属成矿带的代表性矿床之一。成矿地质体为碱长花岗斑岩,与下石炭统灰岩接触带发生大规模矽卡岩化,形成大型钨、钼、铋、萤石以及铁的共生矿床。围绕矽卡岩向外,分布铜锌、铅锌、铅锌银的分带,对应的矿化组合分别为粗粒磁黄铁矿-闪锌矿-黄铜矿、中粗粒磁黄铁矿-闪锌矿-方铅矿、胶状黄铁矿-闪锌矿-方铅矿。围绕花岗斑岩,硫化物矿物的δ³⁴S值呈带状分布,其δ³⁴S总体变化为2.3‰~17.5‰,花岗斑岩中浸染状辉钼矿δ³⁴S为17.1‰,矽卡岩中硫化物δ³⁴S>15‰,矽卡岩附近及外侧的铅锌矿体10‰<δ³⁴S<15‰,外围的铅锌银矿体δ³⁴S<10‰。下石炭统中代表沉积特点的细粒浸染状黄铁矿δ³⁴S为-3.1‰~-22.6‰。铅同位素²⁰⁶Pb/²⁰⁴Pb为18.525~18.603,²⁰⁷Pb/²⁰⁴Pb为15.706~15.792,²⁰⁸Pb/²⁰⁴Pb为38.889~39.178。综合研究表明,黄沙坪矿床成矿物质硫和铅主要来自花岗斑岩。经硫同位素热力学平衡计算,引起δ³⁴S值围绕花岗斑岩体分带的主要原因是随温度下降以及物理化学条件变化导致的热力学分馏作用,其次是沉积岩围岩中低δ³⁴S值硫的加入。对南岭地区花岗岩、古生代地层等的δ³⁴S值对比研究发现,引起花岗斑岩岩浆高δ³⁴S值的主要原因是深部富含硫化物(δ³⁴S值高)地层对富含挥发份(Li-F)的碱长花岗岩岩浆的混染作用,其次是成矿作用过程中地层与岩浆的相互作用(包括同化混染)。围绕黄沙坪矿床,湘南地区矽卡岩型钨多金属矿存在一个较高的δ³⁴S值分布区。宝山矽卡岩型Cu-Mo-Pb-Zn矿床矿石硫化物δ³⁴S为-1‰~3.6‰,²⁰⁶Pb/²⁰⁴Pb为18.602~18.672,²⁰⁷Pb/²⁰⁴Pb为15.693~15.780,²⁰⁸Pb/²⁰⁴Pb为38.901~39.186。因此,宝山矿床与黄沙坪矿床的物质来源和成矿机制不同,宝山矿床硫、铅同位素组成集中,分布范围不同于黄沙坪,成矿物质来自岩浆岩。黄沙坪、宝山矿床代表了南岭地区燕山早期存在两类不同性质的岩浆活动与成矿组合。     

秦岭凤太矿集区喷流沉积型铅锌矿床S、Pb同位素地球化学特征

凤太矿集区位于秦岭泥盆系铅锌等多金属成矿带的中段,铅锌矿床主要产于中泥盆统古道岭组和上泥盆统星红铺组之间的硅质岩中。对区内三个典型铅锌矿床中S、Pb同位素组成研究表明,铅硐山、八方山、银母寺3个铅锌矿床金属硫化物的δ34S值变化范围较小,均不超过10‰。区内硫化物的δ34S值总体变化于4.3‰~13.2‰,指示S主要来自海水硫酸盐的还原作用。3个矿床矿石矿物的Pb同位素中206 Pb/204 Pb变化于17.775~18.180,207Pb/204Pb变化于15.457~15.805,208Pb/204Pb变化于37.977~38.670。各个矿床之间Pb同位素组成均有较大的重叠,暗示3个铅锌矿床具有相似的铅源。通过Pb同位素构造模式图解以及Δβ-Δγ分类图解分析表明,矿石铅来源于早古生代中期到末期扬子板块向华北板块之下俯冲以及晚古生代扬子板块、秦岭微板块向华北板块俯冲的历程中。     

氮素输入影响下淡水湿地碳过程变化

通过野外控制试验和室内培养试验研究了氮素输入对淡水沼泽湿地碳循环过程的影响。结果表明，氮素的输入能够提高沼泽湿地碳的生物累积，但过多的氮素输入则引起植物生产力的降低，并对常年积水沼泽湿地有机物质的分解有抑制作用。在非淹水条件下，氮素输入后有机物质的分解速率明显大于淹水条件，说明水文条件和氮素输入对枯落物的分解过程都有重要的影响，只是在不同环境条件下的响应存在一定的差异。氮素输入后，植物—土壤系统CO2排放量增大；但是，过多氮素输入后植物—土壤系统呼吸速率降低，这说明一定量的氮素输入可促进植物的生长和根的发育，对微生物的活性也有一定的影响，但过多的氮素输入则会对这些过程产生一定的抑制作用。氮素输入对土壤溶解有机碳（DOC）有明显的影响。氮素输入后，根层土壤DOC含量明显降低（P<0.05），不同土壤深度DOC的变化有一定的差异。     

中国CO2地质埋存关联技术的现状

CO2地质埋存是减少CO2净排放量的有效措施之一。CO2地质埋存技术在发达国家已有十几年的研究历史。目前,我国这方面的研究工作刚刚起步,因此,很有必要对我国CO2地质埋存的技术现状进行调查。CO2地质埋存过程主要包括3个要素：从发电厂或者工业生产过程中回收CO2;将CO2运送到埋存场地;CO2注入与埋存。其中的很多技术在现有工业以及石油、天然气开采等行业中已经存在。对我国现有工业以及石油、天然气开采等行业中涉及到的CO2回收、运输以及注入与埋存等技术的现状进行了初步调查,并与国外进行对比。结果表明,我国CO2地质埋存技术现状与国外存在一定的差距,但还是有一定的技术基础,尤其是在CO2回收与注入方面有一定的实践经验。     

An integrated analysis of air pollution from US coal-fired power plants

The United States is one of the world's leaders in electricity production, generating about 4116 billion kWh in 2021, of which coal accounted for 21.8% of the total. This study applies an integrated approach using both terrestrial and satellite data to specifically examine emissions from coal-fired power plants and its spatial extent. The study also highlights the effectiveness of government policies to reduce emissions. It was found that emission of pollutants from the country's energy sector has been steadily declining, with annual emissions of sulfur dioxide (SO₂) and nitrogen oxides (NO_x) decreasing from the US electric power sector between 1990 and 2020 by 93.4% and 84.8%, respectively, and carbon dioxide (CO₂) by 37% between 2007 and 2020. Although overall emissions from coal-fired power plants are declining, some individual plants have yet to install environmental equipment to control emissions. According to US government data, major emitters of SO₂, NO_x, and CO₂ in the US are the Martin Lake power plant in East Texas, the Labadie power plant near St. Louis, Missouri, and the James H Miller Jr plant near Birmingham, Alabama. This study also integrates TROPOMI satellite data to detect point emissions from individual power plants. While the highest levels of measured pollutants were over the country's major cities and areas of fossil fuel extraction, TROPOMI could clearly distinguish the pollution caused by power plants in more rural areas. Although the US has made great strides in reducing emissions from coal-fired power plants, these plants still represent a major source of pollution and remain a major concern. Totally eliminating coal as a power source will be difficult with the higher power demands resulting from the transition to electric automobiles.