Estimating greenhouse gas emissions from open-cut coal mining: application to the Sydney Basin

A new site-specific (Tier 3) method has been developed to determine greenhouse gas emissions from open coal mining. The Tier 3 method presented here is based on extensive measurement of gas emissions from open-cut coal mines and the physics of gas desorption from coal. It was adopted by Australian National Greenhouse and Energy Reporting in 2009 and since 2012 formed the scientific basis for the Australian Government guidelines on calculating greenhouse gas emissions from open cut mines. The main strength of this method is its site-specific nature and accuracy, as well as its ability to be integrated with routine coal exploration programs. New concepts were produced for the model: a coal mine is regarded as a ‘gas reservoir,’ with coal seam gas being emitted from a ‘gas release zone’ that consists of sedimentary geological units (emission layers) above and below the base of the mine. The primary data required for the method are the in situ gas content and gas composition of the coal and carbonaceous rocks contained within the gas-release zone. These data are obtained through direct measurement of gas desorption from bore cores. To reduce gas drilling, a mine lease is compartmentalised into ‘gas zones’ of similar gas content and reservoir properties. The outputs of the method are emission density (the potential volume of gas emitted from mining site per unit area of the ground surface) and emission factor (the gas volume emitted per tonne of raw coal extracted). Owing to spatial variability and errors of measurement, the estimate of emissions is associated with uncertainty. A simple method of calculating uncertainty of emissions is presented in this work.     

General contents of JOURNAL OF PALAEOGEOGRAPHY,2014

正~~     

用区域气候模式模拟人为硫酸盐气溶胶在气候变化中的作用

使用新版RegCM2区域气候模式，单向嵌套澳大利亚CSIROR21L9全球海-气耦合模式，在C02加倍情况下引人人为硫酸盐气溶胶直接气候效应，进行了其对中国气候变化影响的试验。结果表明，硫酸盐气溶胶的直接气候效应，对地面气温为降温作用，其中在冬半年和在南方更明显；对降水的影响为全国各月平均降水将以减少为主，年平均降水变化的基本特点为在中国东部以减少为主，西部以增加为主。但无论温度还是降水变化的数值都很小。     

“Smashing the Moon”Accelerating Global Warming

At the beginning of the 21st century, the world is facing too many natural and artificial disasters, and man is also facing various decisions difficult to be made. The evidence for the earth warming-up is more clear year by year and natural disaster occurs frequently and economic loss in miserable situation, moreover, the evil consequence from the lose of control technologically, overage development is more serious year after year and the daily ecological envi-ronment of man is trending toward…     

Exposure ages and radiogenic ages of ureilite(GRV 024516) and ordinary chondrite(GRV 024517) from Antarctica

The GRV 024516 and GRV 024517 meteorite samples collected from Grove Montains,Antactica are ureilite and H5 ordinary chondrite,respectively.Based on the study of mineralogy-petrology,the cosmic-ray exposure ages and gas retention ages of these two meteorites were determinated and calculated.Their cosmic-ray exposure ages are 33.3 Ma,51.7 Ma,and gas retention ages are 1936.8 Ma and 3720 Ma,respectively.The ureilite contains diamond,graphite and amorphous C,which are mainly carrier of noble gases indicating obviously shock metamorphism effects,which induced 40Ar partial loss.The H5 chondrite indicates thermal metamorphism of parent body,its gas retention age fall the range between 3220 Ma and 4510 Ma of the least shocked H5 chondrites     

On the propagation of hydromagnetic waves in a plasma of thermal and suprathermal components

The propagation of MHD waves is studied when two ideal fluids, thermal and suprathermal gases, coupled by magnetic field are moving with the steady flow velocity. The fluids move independently in a direction perpendicular to the magnetic field but gets coupled along the field. Due to the presence of flow in suprathermal and thermal fluids there appears forward and backward waves. All the forward and backward modes propagate in such a way that their rate of change of phase speed with the thermal Mach number is same. It is also found that besides the usual hydromagnetic modes there appears a suprathermal mode which propagates with faster speed. Surface waves are also examined on an interface formed with composite plasma (suprathermal and thermal gases) on one side and the other is a non-magnetized plasma. In this case, the modes obtained are two or three depending on whether the sound velocity in thermal gas is equal to or greater than the sound velocity in suprathermal gas. The results lead to the conclusion that the interaction of thermal and suprathermal components may lead to the occurrence of an additional mode called suprathermal mode whose phase velocity is higher than all the other modes.     

桂林地区岩溶水中矿物和气体溶解量计算

本文在对桂林地区７４个岩溶水水样化学分析结果进行综合、归纳和分析之后认为，该区岩溶水化学成分是在当地雨水化学成分的基础上，经过水对岩石中的石膏、方解石及白云石和大气中的ＣＯ_２发生溶解作用而形成的。为了验证这一推论，笔者还运用质量守恒计算法，对上述水化学分析结果相对于当地雨水的矿物和ＣＯ_２气体溶解量进行了计算。文中还对岩溶水形成环境进行了分析和讨论。     

青海湖近8000年来演变及发展趋势

本文依据紫果云杉(Picea purpurea Mast)残木、部分地层测年资料、湖成地貌,结合树木年轮和湖水观测资料,探讨近8000年来青海湖演变史并概略预测其发展趋势:8000—3500a.B.P.为暖湿期,3500a.B.P.以来渐趋冷干—干旱,600a.B.P.以来又几经暖湿—冷干的更替;在不考虑温室效应的前提下,大致在133年后湖水达补耗水量平衡期;在温室效应的影响下,湖水将提前于下世纪中叶进入补耗平衡期。     

浅析新生代气候变化与大气温室气体浓度的关系

摘要：根据国内外相关研究结果,对新生代气候变化与温室气体(特别是CO2)浓度在不同时间尺度上的可能关系进行初步归纳和探讨。在构造、轨道和千年时间尺度上,气候变化和温室气体浓度均有显著的相关性,表明温室气体无疑是影响地球气候系统的重要因素。同时,两者亦具有显著的“非耦合”特征,包括新近纪构造尺度上CO2相对稳定水平下的全球变冷和冰量扩张、轨道和千年尺度上CO2浓度变化滞后于气候变化、两半球气候的不对称演化等;两者变化的幅度、趋势和变率也常有不同。这些特征中的多数并不能用地球轨道参数的变化来直接解释,表明除太阳辐射和温室气体外,气候系统内部的其他一些因素或过程有时对过去的气候变化起到了决定性的作用。气候变化与温室气体浓度之间可能存在一种自调节功能,构成一个自调节系统而相互调控,而目前我们对这类过程与机理所知尚少。CO2、CH4等作为温室气体,在上述不同时间尺度的气候变化过程中,无疑对气温具正反馈效应。地质尺度上气候变化与温室气体浓度的关系与机理有助于理解当前全球增温的机制,但把过去与现在类比的同时,也要考虑其他边界条件的不同。加强气候模拟与记录对比的研究,对理解上述问题有望发挥重要作用。 关键词：新生代气候;温室气体;碳循环;人类活动