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1.
气溶胶吸收及气候效应研究的新进展 总被引：14，自引：1，他引：13
最新研究结果表明仅关注气溶胶大气顶辐射强迫是不够的,特别是对于在短波辐射区域存在较强吸收的气溶胶类型,如烟尘、沙尘气溶胶。INDOEX实验表明来自印度次大陆的吸收性气溶胶产生的地表辐射强迫在量值上是大气顶辐射强迫的3倍左右,二者的差额以大气辐射加热的形式出现。气溶胶吸收通过加热气溶胶层所在大气,减少地表太阳辐射,影响地面蒸发,改变大气稳定度,从而影响水分循环。另外气溶胶的吸收对云产生“燃烧效应”,从而可能导致云量下降。鉴于气溶胶吸收的重要性,气溶胶吸收问题是当前气溶胶气候效应研究的一个热点问题。尽管关于气溶胶的吸收问题以及与之有关的气候效应还存在很大不确定性,根据观测事实或模拟结果得出的结论差别明显,但勿庸置疑的是气溶胶吸收是一个急需深入探讨的课题。由于我国北方地区春季沙尘活动十分频繁,而东部地区由于能源结构以及能源利用效率等问题致使气溶胶中吸收性成分（碳黑）含量偏高,一些资料分析以及模式研究结果均表明我国发生了一些有别于全球或其他地区的独特气候变化现象,初步分析表明气溶胶吸收在其中可能发挥了一定作用,因此加强我国气溶胶吸收特性的观测和理论研究,结合全球或区域气候模式,深入认识我国气溶胶辐射强迫、气候效应具有重要的科学意义,另外对于评估我国近年来采取的一些卓有成效的污染控制措施的环境和气候效应也是必不可少的。 相似文献
2.
论大气二氧化碳温室效应的饱和度 总被引：4，自引：0，他引：4
利用最新版本的大气分子吸收光谱资料HITRAN2000，用精确的逐线积分算法，计算了大气CO2浓度变化后产生的辐射强迫。在此基础上，研究了CO2温室效应的饱和度以及影响CO2辐射强迫的各种因子。主要结论如下：地面温度愈高，一般辐射强迫也愈大，但辐射强迫并不完全取决于地面温度，它还受大气温度廓线的强烈影响；研究的 6种模式大气中，吸收带重叠对热带大气的CO2辐射强迫影响最大，对亚极冬季大气的影响最小；与长波辐射强迫相比，短波辐射强迫的贡献很小；CO2的温室效应在15μm带中心等波段确实已经达到饱和，但在其它（15μm带两翼，10μm，5.2μm带等）波段远未达到饱和，在最近的将来也不会达到饱和。 相似文献
3.
《地球科学进展》2016,(3)
印度半岛和东亚是气溶胶大值区,也是亚洲季风的主要影响区域,季风和季风降水的变化对季风区的经济尤其是农业生产有重大影响。气溶胶影响印度季风的研究开始较早,研究工作也较多,已取得了较为全面的进展。早期研究表明大气棕云导致负辐射强迫可减缓温室气体带来的增暖。现有研究表明吸收性气溶胶对印度季风爆发早期有增强作用,随后气溶胶对印度和东亚夏季风有减弱作用。由于影响季风的因子较多、研究工作较为复杂,现有的气溶胶影响亚洲季风的研究还存在不确定性。回顾和概括了前人的研究,通过气溶胶影响东亚季风与印度季风的对比,讨论现有研究的不足,并为未来气溶胶影响季风特别是影响东亚夏季风的研究指出方向。 相似文献
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SO2排放,硫酸盐气溶胶和气候变化 总被引：3，自引：0，他引：3
工业ＳＯ２排放的增加使对流层大气中硫酸盐气溶胶浓度增大，硫酸盐气溶胶通过其直接和间接辐射强迫作用影响气候变化。有关的研究结果显示：硫到盐气溶胶的冷却效应在一定程度上抵消了温室效应，北半球增暖趋势的减缓和日较差的减小可能与大气中人为硫酸盐气溶胶浓度的增加有关。 相似文献
5.
人类活动引起的我国西北地区21世纪温度和降水变化情景分析 总被引：42，自引：7，他引：35
使用IPCCWG1第三次科学评估报告中给出的7个全球气候系统模式的模拟预测结果,分析了人类活动对中国西北地区气候变化的影响.模拟结果表明,由于温室气体增加(GG)或温室气体与硫化物气溶胶(GS)增加,21世纪西北地区气温将可能平均变暖42～60℃·100a-1.降水的变化较为复杂,由于温室气体的影响,未来西北地区降水将增加;考虑温室气体和硫化物气溶胶的共同影响,则略有增加.模式平均结果表明,未来西北地区降水将可能增加15～39mm·100a-1. 相似文献
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人类活动对于我国气象干旱的影响分析 总被引：1，自引：0，他引：1
干旱导致相当的经济社会损失和生态环境破坏。基于CMIP6多模式历史模拟降水数据,计算标准化降水指数,采用阈值识别干旱事件,设计对比实验评估人类活动对于我国1851—2005年干旱的影响。结果表明：自然强迫下,我国呈现略微湿润化趋势;人类活动和自然强迫下,我国东南地区干旱频率显著提高、干旱持续时间显著增长、最大干旱强度显著增加,西北地区干旱频率则显著降低。人类活动使我国54.2%的网格干旱频率提高值超过了自然强迫下提高值的最大10%分位数,最大干旱持续时间和最大干旱强度中分别为41.8%、31.6%。气溶胶使得我国大部分地区干旱频率显著提高,温室气体则使得干旱频率显著降低。 相似文献
8.
黑碳被认为是除温室气体外对气候变暖贡献最大的辐射强迫因子。三极（北极、南极和青藏高原）地区是全球雪冰分布最集中的区域,沉积至雪冰中的黑碳可反映人类活动的历史变化,并可能导致反照率降低而影响物质能量平衡。通过系统回顾三极地区雪冰黑碳的研究方法、空间分布、时间变化及其造成的辐射强迫,得到的研究结果表明： 由于处于不同的地理位置和环境条件,三极雪冰中黑碳的时空分布及其辐射强迫差异较大,其中青藏高原是浓度和辐射强迫影响最大的地区,也是对水资源和生态安全潜在影响最严重的区域。三极地区雪冰中保存着长时间序列的黑碳沉积记录,是研究自然变率、人类活动影响黑碳沉积历史（如北极与青藏高原冰芯中记录的工业革命以来黑碳沉积的快速上升）的良好介质,同样为模型预测未来变化提供了数据支持。三极地区是全球变化的指示器和放大器,在全球变暖不断加剧的背景下,黑碳必然会在未来的三极地区气候演变中扮演更为重要的角色。 相似文献
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北京斋堂黄土中主要温室气体组分特征 总被引：4，自引：3，他引：1
根据极地冰芯等资料已经重建了过去大气温室气体（主要是CO2,CH4）浓度的变化。由于人类活动的影响,温室气体的含量自工业革命以来有了明显的上升,其影响表现为全球变暖。如果维持现在的CO2产放水平,根据气候模式预测到下个世纪末全球温度将增加l-3.5℃,可能极大地改变人类生存的环境。但是预测结果还存在着很大的不确定性,其中一个重要因素是对温室气体的源和汇的理解还不完善,有相当数量的CO2声向不明（即未知汇）.目前倾向认为,在北半球的中纬度地带可能存在着一个巨大的陆地生态系统汇（植被和土壤）.中国黄土分布在北半球中纬度,实际上是在干旱一半干旱气候条件下形成的一套巨厚的成土作用较弱的黄土一古土壤序列。 相似文献
10.
如果通过限制温室气体排放量来减缓全球变化的速度和规模,那么进一步就要确定应限制哪些温室气体。选择限制对象的基本原则是:(1)这种气体在温室效应的增强上起着主要作用;(2)这种气体的排放部份或全部是人类活动造成的;(3)对其进行控制是可行的。不同温室气体引起全球变暖的能力是不同的,这种能力决定于它们吸收远红外辐射的能力、在大气层中的平均寿命及其排放量。人们最关心的是今后100年内的全球气候变化。大气层中短寿命的气体即使吸收远红外辐射的能力很强,在以世纪为单位的长时间内的累积影响仍然较小。综合吸收能力与寿命两种因素可以计算出各种温室气体对全球变暖的潜在能 相似文献
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Erika P.Blanco-Donado Ismael L.Schneider Paulo Artaxo Jesus Lozano-Osorio Luana Portz Marcos L.S.Oliveira 《地学前缘(英文版)》2022,(1):404-416
Black carbon(BC)is one of the short-lived air pollutants that contributes significantly to aerosol radiative forcing and global climate change.It is emitted by the incomplete combustion of fossil fuels,biofuels,and biomass.Urban environments are quite complex and thus,the use of mobile jointly with fixed monitoring provides a better understanding of the dynamics of BC distribution in such areas.The present study addresses the measurement of BC concentration using real-time mobile and ambient monitoring in Barranquilla,an industrialized urban area of the Colombian Caribbean.A microaethalometer(MA200)and an aethalometer(AE33)were used for measuring the BC concentration.The absorption ?ngstr?m exponent(AAE)values were determined for the study area,for identifying the BC emission sources.The results of the ambient sampling show that vehicle traffic emissions prevail;however,the influence of biomass burning was also observed.The mean ambient BC concentration was found to be 1.04±1.03μg/m3 and varied between 0.5 and 4.0μg/m3.From the mobile measurements obtained in real traffic conditions on the road,a much higher average value of 16.1±16.5μg/m3 was measured.Many parts of the city showed BC concentrations higher than 20μg/m3.The spatial distribution of BC concentration shows that vehicle emissions and traffic jams,a consequence of road and transport infrastructure,are the factors that most affect the BC concentration.A comparison of results obtained from two aethalometers indicates that the concentrations measured by MA200 are 9%lower than those measured by AE33.The AAE obtained was found to vary between 1.1 and 1.6,indicating vehicular emissions as the most crucial source.In addition,it was observed that the BC concentration on working days was 2.5 times higher than on the weekends in the case of mobile monitoring and 1.5 times higher in the case of ambient monitoring. 相似文献
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Doklady Earth Sciences - Quantitative estimates of the contribution of anthropogenic forcing, characterized by changes in the radiative forcing of greenhouse gases in the atmosphere, and key modes... 相似文献
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India Peninsula and East Asia are high aerosol loading regions as well as major regions influenced by Asian monsoon. The changes of monsoon intensity and precipitation have great influence on economy, especially agricultural production of monsoon regions. There are many researches of impacts of aerosol on Indian monsoon, which have achieved many comprehensive progresses. Earlier researches show that atmospheric brown cloud caused negative radiative forcing and weakened the warming induced by greenhouse gases. Current researches show that absorbing aerosol enhanced the Indian monsoon and increased rainfall in pre-monsoon season, while the scattering effect of aerosol weakened the Indian summer monsoon and the East Asian summer monsoon and rainfall in monsoon season. Due to so many factors affecting the monsoon, researches of aerosol impacts on monsoon become more complex. Thus, these results remain uncertain. This paper reviews previous researches and generalizes the mechanisms of impacts of aerosols on Asian monsoon. By comparing the East Asian summer monsoon with the Indian summer monsoon, we discussed deficiencies of the prior researches, and pointed out the direction for future researches about the impact of aerosol on the Asian summer monsoon, especially on the East Asian summer monsoon. 相似文献
16.
海洋生物气溶胶增加可能导致晚新生代全球变冷的模型计算 总被引：1，自引：0，他引：1
整合海洋碳、锶、锇同位素记录的地球化学元素循环模型表明,晚新生代大陆化学风化通量随着全球物理侵蚀的增强而升高,促使更多的营养元素磷输入到海洋中,引起海洋生物生产力的爆发,而浮游生物产生大量的二甲基硫最终导致海洋上空的大气气溶胶浓度急剧上升。气溶胶浓度增加一方面会增加云的覆盖率和反射率,据初步估计,该效应导致距今7 Ma 内地表接收的太阳能减少了16.5 Wm-2,相当于全球平衡温度降低13 ℃;另一方面会抑止云层的降水效能,有利于水汽向高纬地区传输并形成降雪,最终促进两极冰盖生长,从而驱动新生代晚期全球性的气候变冷。 相似文献
17.
S Naseema Beegum Haifa Ben Romdhane Mohammed Tauha Ali Peter Armstrong Hosni Ghedira 《Journal of Earth System Science》2016,125(8):1579-1602
The present study is on the aerosol optical and radiative properties in the short-wave radiation and its climate implications at the arid city of Abu Dhabi (24.42 °N, 54.61 °E, 4.5 m MSL), in the United Arab Emirates. The direct aerosol radiative forcings (ARF) in the short-wave region at the top (TOA) and bottom of the atmosphere (BOA) are estimated using a hybrid approach, making use of discrete ordinate radiative transfer method in conjunction with the short-wave flux and spectral aerosol optical depth (AOD) measurements, over a period of 3 years (June 2012–July 2015), at Abu Dhabi located at the south-west coast of the Arabian Gulf. The inferred microphysical properties of aerosols at the measurement site indicate strong seasonal variations from the dominance of coarse mode mineral dust aerosols during spring (March–May) and summer (June–September), to the abundance of fine/accumulation mode aerosols mainly from combustion of fossil-fuel and bio-fuel during autumn (October–November) and winter (December–February) seasons. The monthly mean diurnally averaged ARF at the BOA (TOA) varies from ?13.2 Wm?2 (～?0.96 Wm?2) in November to ?39.4 Wm?2 (?11.4 Wm?2) in August with higher magnitudes of the forcing values during spring/summer seasons and lower values during autumn/winter seasons. The atmospheric aerosol forcing varies from + 12.2 Wm?2 (November) to 28.2 Wm?2 (June) with higher values throughout the spring and summer seasons, suggesting the importance of mineral dust aerosols towards the solar dimming. Seasonally, highest values of the forcing efficiency at the surface are observed in spring (?85.0 ± 4.1 W m?2 τ ?1) followed closely by winter (?79.2 ± 7.1 W m?2 τ ?1) and the lowest values during autumn season (?54 ± 4.3 W m?2 τ ?1). The study concludes with the variations of the atmospheric heating rates induced by the forcing. Highest heating rate is observed in June (0.39 K day ?1) and the lowest in November (0.17 K day ?1) and the temporal variability of this parameter is linearly associated with the aerosol absorption index. 相似文献
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In this paper, we report some salient features from a suit of special experiments that have been conducted over a coastal site (Mumbai) during February 23–March 03, 2010, encompassing an Indian festival, namely Holi, using solar radiometers and pyranometer. The results of the analysis of observations at the experimental site show higher (more than double) aerosol optical depth, water vapor, and lower down-welling short-wave radiative flux during the festival period. This is considered to be due to anthropogenic activities and associated meteorological conditions at the experimental location. To illustrate further, Angstrom parameters (alpha, denoting the aerosol size distribution, and beta, representing the loading) are examined. These parameters are found to be greater on Holi day as compared to those on the normal (control, pre-, and post-Holi) days, suggesting an increase in accumulation mode (smaller size) particle loading. The aerosol size spectra exhibited bimodal/power-law distribution with a dominant peak, modulated by anthropogenic activities, involving local and long-range transport of dust and smoke (emanated from biomass-burning) aerosols, which is consistent with MODIS satellite observations. The aerosol direct radiative forcing estimation indicated cooling at the bottom of the atmosphere. 相似文献
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During the field cruises of the Indian Ocean Experiment (INDOEX) extensive measurements on the atmospheric chemical and aerosol composition are undertaken to study the long-range transport of air pollution from south and southeast Asia towards the Indian Ocean during the dry monsoon season in 1998 and 1999. The present paper discusses the temporal and spatial variations in aerosols and aerosol forcing during the winter monsoon season (January-March) for INDOEX first field phase (FFP) in 1998 and INDOEX intensive field phase (IFP) in 1999. An interactive chemistry/aerosol model (LMDZ.3.3) is used to investigate the variation in the spatial distribution of tropospheric sulphate aerosols during 1998 and 1999. The model results depict major enhancement in the sulphate aerosol concentrations, radiative forcing (RF) and optical depth over the Indian subcontinent and adjoining marine areas between INDOEX-FFP and IFP. A significant increase in transport of sulphate aerosols from the continents to the Indian Ocean region has also been simulated during the winter monsoon in 1999. The mean RF over INDOEX-FFP in 1998 is found to be ?1.2 Wm–2 while it increased to ?1.85 Wm–2 during INDOEX-IFP in 1999. Model results reveal a mean sulphate aerosol optical depth (AOD) of 0.08 and 0.14 over Indian subcontinent during 1998 and 1999, respectively. The model results suggest that elevated AOD downwind of source regions in India can significantly affect the regional air quality and adjoining marine environments. 相似文献