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1.
基于CMIP6的16个全球模式试验数据,多模式集合预估了《巴黎协定》1.5°C/2°C温升目标下“一带一路”倡议的主要陆域未来气温和降水变化。与观测相比较,多模式集合能够比较准确地刻画“一带一路”主要陆域1995～2014年气温和降水的空间结构特征。在SSP2-4.5、SSP3-7.0和SSP5-8.5三种不同路径情景下,相对于工业革命前（1850～1900年）,全球升温1.5°C与2°C分别将发生在2020年代中后期与2040年左右。全球1.5°C与2°C温升目标下,预计“一带一路”陆域平均的气温分别显著升高1.84°C和2.43°C,两者相差0.59°C,模式间标准差分别为0.18°C和0.21°C;区域平均的降水分别显著增加20.14 mm/a和30.02 mm/a,相差9.88 mm/a,模式间标准差分别为10.79 mm/a和13.72 mm/a。两种温升目标下,“一带一路”主要陆域气温空间上均表现为一致性显著增暖,高纬度的增温幅度普遍比低纬度大;降水变化具有明显的空间差异性,地中海与黑海地区、中国南部至中南半岛地区减少,其他地区的降水普遍增加。P-E指数表征的干旱化未来在欧洲地区、中国南部至中南半岛地区、南亚印度东部地区、东南亚和赤道非洲中部地区达到最大。 相似文献
2.
利用国家气候中心大气环流模式BCC_AGCM2.0,结合IPCC 第五次评估报告给出的最新有效辐射强迫的概念,模拟了自工业革命以来由于人类活动造成的甲烷浓度增加引起的有效辐射强迫及其气候效应。得出如下结论：甲烷浓度增加造成的有效辐射强迫的全球平均值为0.49 W/m2;导致全球平均地表温度上升0.31 ℃,升温主要分布在南北半球中高纬度地区;全球平均降水量增加0.02 mm/d,赤道辐合带降水中心有向北移动的趋势;地表水汽通量的变化使高纬度地区云量增加（约4%）,而中低纬度地区云量减小（约-3%）。 相似文献
3.
Aerosol indirect effects (AIEs) on global climate were quantitatively investigated by introducing aerosol-cloud interaction parameterizations for water stratus clouds into an AGCM (BCC AGCM2.0.1), which was developed by the National Climate Center of the China Meteorological Administration. The study yielded a global annual mean of -1.14 W m-2 for the first indirect radiative forcing (IRF), with an obvious seasonal change. In summer, large forcing mainly occurred in mid to high latitudes of the Northern Hem... 相似文献
4.
Recent observations suggest that the abundance of ozone between 2 and 8 km in the Northern Hemisphere mid-latitudes has increased by about 12% during the period from 1970 to 1981. Earlier estimates were somewhat more conservative suggesting increases at the rate of 7% per decade since the start of regular observations in 1967. Previous photochemical model studies have indicated that tropospheric ozone concentrations would increase with increases in emissions of CO, CH4 and NO
x
. This paper presents an analysis of tropospheric ozone which suggests that a significant portion of its increase may be attributed to the increase in global anthropogenic NO
x
emissions during this period while the contribution of CH4 to the increase is quite small. Two statistical models are presented for estimating annual global anthropogenic emissions of NO
x
and are used to derive the trend in the emissions for the years 1966–1980. These show steady increase in the emissions during this interval except for brief periods of leveling off after 1973 and 1978. The impact of this increase in emissions on ozone is estimated by calculations with a onedimensional (latitudinal) model which includes coupled tropospheric photochemistry and diffusive meridional transport. Steady-state photochemical calculations with prescribed NO
x
emissions appropriate for 1966 and 1980 indicate an ozone increase of 8–11% in the Northern Hemisphere, a result which is compatible with the rise in ozone suggested by the observations. 相似文献
5.
Shu Li Tijian Wang Prodromos Zanis Dimitris Melas Bingliang Zhuang 《Acta Meteorologica Sinica》2018,32(2):279-287
The spatial distribution, radiative forcing, and climatic effects of tropospheric ozone in China during summer were investigated by using the regional climate model RegCM4. The results revealed that the tropospheric ozone column concentration was high in East China, Central China, North China, and the Sichuan basin during summer. The increase in tropospheric ozone levels since the industrialization era produced clear-sky shortwave and clear-sky longwave radiative forcing of 0.18 and 0.71 W m–2, respectively, which increased the average surface air temperature by 0.06 K and the average precipitation by 0.22 mm day–1 over eastern China during summer. In addition, tropospheric ozone increased the land–sea thermal contrast, leading to an enhancement of East Asian summer monsoon circulation over southern China and a weakening over northern China. The notable increase in surface air temperature in northwestern China, East China, and North China could be attributed to the absorption of longwave radiation by ozone, negative cloud amount anomaly, and corresponding positive shortwave radiation anomaly. There was a substantial increase in precipitation in the middle and lower reaches of the Yangtze River. It was related to the enhanced upward motion and the increased water vapor brought by strengthened southerly winds in the lower troposphere. 相似文献
6.
The climate response to an increase in carbon dioxide and sea surface temperatures is examined using the Météo-France climate model. This model has a high vertical resolution in the stratosphere and predicts the evolution of the ozone mixing ratio. This quantity is fully interactive with radiation and photochemical production and loss rates are accounted for. Results from a 5-year control run indicate a reasonable agreement with observed climatologies. A 5-year simulation is performed with a doubled CO2 concentration using, as lower boundary conditions, mean surface temperatures anomalies and sea ice limits predicted for the years 56–65 of a 100-year transient simulation performed at Hamburg with a global coupled atmosphere-ocean model. The perturbed simulation produces a global mean surface air warming of 1.4 K and an increase in global mean precipitation rate of 4%. Outside the high latitudes in the Northern Hemisphere, the model simulates a strong cooling in the stratosphere reaching 10 K near the stratopause. Temperature increases are noticed in the lower polar stratosphere of the Northern Hemisphere caused by an intensification in the frequency of sudden warmings in the perturbed simulation. The low and mid-latitude stratospheric cooling leads to an ozone column enhancement of about 5%. Other features present in similar studies are exhibited in the troposphere such as the stronger surface warming over polar regions of the Northern Hemisphere, the summer time soil moisture drying in mid-latitudes and the increase in high convective cloudiness in tropical regions.This paper was presented at the Second International Conference on Modelling of Global Climate Variability, held in Hamburg 7–11 September 1992 under the auspices of the Max Planck Institute for Meteorology. Guest Editor for these papers is L. Dümenil
Correspondence to: JF Mahfouf 相似文献
7.
Global monsoon: Dominant mode of annual variation in the tropics 总被引：13，自引：0，他引：13
This paper discusses the concept of global monsoon. We demonstrate that the primary climatological features of the tropical precipitation and low-level circulation can be represented by a three-parameter metrics: the annual mean and two major modes of annual variation, namely, a solstitial mode and an equinoctial asymmetric mode. Together, the two major modes of annual cycle account for 84% of the annual variance and they represent the global monsoon. The global monsoon precipitation domain can be delineated by a simple monsoon precipitation index (MPI), which is the local annual range of precipitation (MJJAS minus NDJFM in the Northern Hemisphere and NDJFM minus MJJAS in the Southern Hemisphere) normalized by the annual mean precipitation. The monsoon domain can be defined by annual range exceeding 300 mm and the MPI exceeding 50%.The three-parameter precipitation climatology metrics and global monsoon domain proposed in the present paper provides a valuable objective tool for gauging the climate models’ performance on simulation and prediction of the mean climate and annual cycle. The metrics are used to evaluate the precipitation climatology in three global reanalysis products (ERA40, NCEP2, and JRA25) in terms of their pattern correlation coefficients and root mean square errors with reference to observations. The ensemble mean of the three analysis datasets is considerably superior to any of the individual reanalysis data in representing annual mean, annual cycle, and the global monsoon domain. A major common deficiency is found over the Southeast Asia-Philippine Sea and southeast North America-Caribbean Sea where the east–west land–ocean thermal contrast and meridional hemispheric thermal contrast coexist. It is speculated that the weakness is caused by models’ unrealistic representation of Subtropical High and under-represented tropical storm activity, as well as by neglecting atmosphere–ocean interaction in the reanalysis. It is recommended that ensemble mean of reanalysis datasets be used for improving global precipitation climatology and water cycle budget. This paper also explains why the latitudinal asymmetry in the tropical circulation decreases with altitude. 相似文献
8.
本文首先对中国PM2.5和近地面臭氧浓度的观测进行了简要的综述;并利用2010-2013年全球对流层臭氧的卫星观测数据给出了对流层臭氧浓度在全球和中国地区的分布特征,其平均值分别为29.78 DU和33.97 DU。然后,利用一个气溶胶大气化学-全球气候双向耦合模式模拟了中国地区PM2.5的浓度分布和季节变化,其年平均值为0.51×10-8 kg/m3。在此基础上又分析了5种典型气溶胶对PM2.5总浓度在不同季节的贡献。结合IPCC第五次评估报告（AR5）,讨论了气溶胶和温室气体及其前体物的排放与辐射强迫的联系,以及减排大气臭氧前体物和气溶胶颗粒物质（PM）对气候变化的可能影响。指出减排臭氧前体物对气候的影响还不完全清楚,对短寿命的温室气体和黑碳气溶胶的减排是一种短期（未来50年）的辅助措施;为了保证全球平均温度增长不超过2℃,减少二氧化碳的排放仍是我们需要坚持的长期战略。短期和长期的减排战略对于保护环境和减缓气候变化都是至关重要的。 相似文献
9.
The midlatitude westerlies are one of the major components of the global atmospheric circulation. They play an important role in midlatitude weather and climate, and are particularly significant in interpreting aeolian sediments. In this study, we analyzed the behavior and the possible mechanism involved in the change of the westerlies, mainly in terms of the jet stream position, in the mid-Pliocene warm period(3.3 to 3.0 million years ago) using simulations of 15 climate models from the Pliocene Model Intercomparison Project(Plio MIP). Compared to the reference period, the mid-Pliocene midlatitude westerlies generally shifted poleward(approximately 3.6 of latitude in the Northern Hemisphere and 1.9 of latitude in the Southern Hemisphere at 850 h Pa level) with a dipole pattern. The dipole pattern of the tropospheric zonal wind anomalies was closely related to the change of the tropospheric meridional temperature gradient as a result of thermal structure adjustment.The poleward shift of the midlatitude westerly jet corresponded to the poleward shift of the mean meridional circulation.The sea surface temperatures and sea ice may have affected the simulated temperature structure and zonal winds, causing the spread of the westerly anomalies in the mid-Pliocene between the atmosphere-only and coupled atmosphere–ocean general circulation model simulations. 相似文献
10.
Numerical experiments are analyzed for 1860–2100 with the version of the climate model of intermediate complexity of the Obukhov Institute of Atmospheric Physics of the Russian Academy of Sciences (IAP RAS) including the model of general ocean circulation as the oceanic module (CM IAP RAS-GOC) taking account of concentration variations of anthropogenic greenhouse gases and tropospheric sulfate aerosols from the data of observations and reconstructions for the second half of the 19th and for the 20th century and, according to SRES scenarios, in the 21st century. In the 20th century, the model simulates realistically the variations of surface atmospheric temperature, characteristics of heat absorption by the ocean, and oceanic meridional heat transport. The linear trend of global surface atmospheric temperature in the 20th century (in its last 30 years) in this version of the model amounts to 0.5 ± 0.1 K/100 years (0.22 ± 0.05 K/10 years) that is agreed with the observational data. In the 21st century, the global increase in the surface temperature amounts to 2.5 K (3.5 and 4.1 K) for SRES B1 scenario (for SRES A1B and SRES A2 scenarios, respectively). The increase in the surface temperature is the most significant in high latitudes, especially in the Northern Hemisphere and it is higher, on the whole, over the land than over the ocean. The warming near the surface is larger in winter than in summer. The maximum warming is observed in the Arctic and over the land of subpolar latitudes of the Northern Hemisphere reaching 6–10 K by the end of the 21st century in these regions as compared with the end of the 20th century depending on the anthropogenic impact scenario. At the increase in surface temperature in the 20th–21st centuries, the increase in the heat flow to the ocean and the weakening of the heat transport by the ocean from the tropics to the polar area by 1.5–2 times are registered, on the whole. At the warming, the CM IAP RAS-GOC gives the general increase in the annual precipitation amount which is especially appreciable in the tropics and in the storm-track regions. At the global averaging, the precipitation in the 21st century increase by 20–25%. 相似文献
11.
气候模式分辨率作为影响模式模拟结果的重要因素,其对气溶胶与云相互作用的影响尚未全面认识。利用公共大气模型CAM5.3在3种分辨率（2°、1°、0.5°）下,分别采用2000年和1850年气溶胶排放情景进行试验,检验提高分辨率是否能改进气候模式的模拟能力,分析不同分辨率下气溶胶气候效应的异同,探索模式分辨率对气溶胶气候效应数值模拟结果的影响。通过观测资料与模式结果对比发现,提高分辨率可以明显改进模式对总云量、云短波辐射强迫的模拟能力,0.5°分辨率下模拟结果与观测更接近,其他变量并无明显改善。在不同分辨率下,全球平均的气溶胶气候效应较为一致,总云量、云水路径均增加,云短波和长波辐射强迫均加强,而云顶的云滴有效半径和降水均减小,地面气温降低。不同分辨率下,气溶胶增加引起的气溶胶光学厚度、云水路径、地面温度、云短波和长波辐射强迫变化的纬向平均分布相似但大小存在差异;而降水和云量变化的纬向分布与大小均存在较大差异,在区域尺度上还存在较大的不确定性。全球平均而言, 0.5°分辨率下气溶胶的间接辐射强迫相比1°分辨率下的结果降低了2.5%,相比2°分辨率下的结果降低了6.4%。提高模式分辨率可以部分改进模式模拟能力,同时,气溶胶的间接效应随着模式分辨率的提高而减弱。但气溶胶引起的云量、降水的变化在不同分辨率下差异较大,存在较大的不确定性。 相似文献
12.
Carried out is the statistical analysis of contemporary observed variations of air temperature and wind speed in the troposphere of the Northern Hemisphere based on the data on global surface air temperature for 1850–2013 obtained from the University of East Anglia Climate Research Unit (HadCRUT4) and NCEP/NCAR reanalysis (1948–2013). Revealed are the long-term trends of air temperature and wind speed at different constant-pressure levels. Established is the anticipatory role of the zonal atmospheric circulation in the long-term variability of air temperature in the lower troposphere averaged for the zone of 30°–70° N. According to the results of correlation analysis, in some areas of the Northern Hemisphere the contribution of the wind speed to air temperature variability makes up not less than 60%. 相似文献
13.
根据TOR卫星数据分析,我国长江三角洲地区对流层O3柱含量的长期变化就全年和大多数月份而言均为增长趋势,1978-2000年间其年均值的增长趋势为0.82 DU/10 a。这种长期变化趋势所引起的气候效应及其对大气氧化性的影响值得进一步研究。结果表明,长江三角洲地区对流层O3柱含量的季节变化与该地区的临安区域大气本底站的地面O3季节变化有着显著的相关关系,临安站的观测数据具有区域代表性。 相似文献
14.
We used a fully coupled chemistry–climate model(version 3 of the Whole Atmosphere Community Climate Model,WACCM3) to investigate the effect of methane(CH4) emission increases,especially in East Asia and North America,on atmospheric temperature,circulation and ozone(O3). We show that CH4 emission increases strengthen westerly winds in the Northern Hemisphere midlatitudes,accelerate the Brewer–Dobson(BD) circulation,and cause an increase in the mass flux across the tropopause. However,the BD circulation in the tropics between 10?S and 10?N at 100 h Pa weakens as CH4 emissions increase in East Asia and strengthens when CH4 emissions increase in North America. When CH4 emissions are increased by 50% in East Asia and 15% globally,the stratospheric temperature cools by up to 0.15 K,and the stratospheric O3 increases by 45 ppbv and 60 ppbv,respectively. A 50% increase of CH4 emissions in North America(with an amplitude of stratospheric O3 increases by 60 ppbv) has a greater influence on the stratospheric O3 than the same CH4 emissions increase in East Asia. CH4 emission increases in East Asia and North America reduce the concentration of tropospheric hydroxyl radicals(4% and 2%,respectively) and increase the concentration of mid-tropospheric O3(5% and 4%,respectively) in the Northern Hemisphere midlatitudes. When CH4 emissions increase in East Asia,the increase in the tropospheric O3 concentration is largest in August. When CH4 emissions increase in North America,the increase in the O3 concentration is largest in July in the mid-troposphere,and in April in the upper troposphere. 相似文献
15.
Climatic change due to land surface alterations 总被引：1，自引：0，他引：1
A primitive equations global zonally averaged climate model is developed. The model includes biofeedback mechanisms. For the Northern Hemisphere the parameterization of biofeedback mechanisms is similar to that used by Gutman et al. (1984). For the Southern Hemisphere new parameterizations are derived. The model simulates reasonably well the mean annual zonally averaged climate and geobotanic zones.Deforestation, desertification and irrigation experiments are performed. In the case of deforestation and desertification there is a reduction in the surface net radiation, evaporation and precipitation and an increase in the surface temperature. In the case of irrigation experiment opposite changes occurred. In all the cases considered the changes in evapotranspiration overcome the effect of surface albedo modification. In all the experiments changes are smaller in the Southern Hemisphere. 相似文献
16.
Analysis of tropospheric ozone residual (TOR) data from satellite measurements indicates an increasing trend of tropospheric ozone over the Yangtze Delta region of China. The increasing trend can be derived both from the annual mean TOR and from the monthly mean TOR except for January and March. The increase rate of the decadal mean TOR was 0.82 DU during 1978-2000. The impact of this long-term trend on the climate and atmospheric oxidizing capacity over the region should be further studied. Data comparison shows a significant correlation between the TOR and surface ozone data collected at Lin'an background station in the Yangtze Delta region, suggesting an internal connection between both quantities. 相似文献
17.
近十五年全球臭氧变化 总被引：16，自引：1，他引：15
利用卫星观测臭氧总含量ＴＯＭＳ（第７版）资料,在剔除季节变化后对全球６０°Ｓ－６０°Ｎ范围首先进行了沿纬度分布的线性趋势和周期分析。结果表明：自本世纪７０年代末,各纬带上的臭氧总量都呈下降趋势,强度随纬度升高而加剧,并发现总体上北半球臭氧的下降趋势较南半球更加明显;同时证实了准两年振荡是臭氧变化中除年周期外最显著的周期。并对臭氧变化中的准两年振荡作了遥相关分析;发现准两年振荡在强度和位相上基本呈纬向分布并主要表现出赤道对称的特征。１３５～１７０°Ｅ地区臭氧总量变化所表现出的不同于其它地区的原因可能是这一地区常年频繁出现的对流活动;而臭氧总量下降趋势表现出的北半球同纬度地区均大于南半球的南北半球差异可能是由两半球人类活动的差异引起 相似文献
18.
本文基于一套在5个全球气候模式结果驱动下,RegCM4区域气候模式对东亚25 km水平分辨率的集合预估,分析了中、高温室气体典型排放路径（RCP4.5和RCP8.5）下,21世纪不同时期新疆地区的未来气候变化。对模式当代气候模拟结果的检验表明,区域模式的模拟集合（ensR）总体上能够很好地再现当代新疆平均气温、降水和极端气温、降水分布特征。ensR预估21世纪未来新疆平均气温和降水将不断升高或增加,RCP8.5下的变化大于RCP4.5。在21世纪末期RCP8.5下,区域年平均气温和降水将分别增加4.9°C和28%（102 mm）,夏季（6～8月）的升温幅度略高于冬季（12～2月）,降水则以冬季增加为主。极端温度以及高温日数同样将不断升高,其中年日最低气温最小值的增幅总体高于年日最高气温最大值,未来新疆地区的极端冷事件将减少,高温、热浪事件将增加。由极端降水指标日最大降水量反应的强降水事件将普遍增加,连续无降水日数总体以减少为主。积雪变化存在一定区域差异,具体表现为除塔里木盆地外的普遍减少。对总径流量和表层土壤湿度的预估分析表明,二者在新疆地区均以增加为主,但水文干旱在北疆会加重。ensR各模拟间无论是在当代模拟还是未来预估中都表现出较好的一致性,但在变化的具体数量及个别情况下符号均存在一定差异。最后,综合考虑ensR对各要素的预估发现,总体而言新疆未来更趋向于“暖湿化”,但这不会改变其干旱、半干旱气候的本质,而且水文干旱频率在一些地区会增加,未来新疆的水资源状况仍不容乐观。 相似文献
19.
L. D. Danny Harvey 《Climatic change》1988,13(2):191-224
A seasonal energy balance climate model containing a detailed treatment of surface and planetary albedo, and in which seasonally varying land snow and sea ice amounts are simulated in terms of a number of explicit physical processes, is used to investigate the role of high latitude ice, snow, and vegetation feedback processes. Feedback processes are quantified by computing changes in radiative forcing and feedback factors associated with individual processes. Global sea ice albedo feedback is 5–8 times stronger than global land snowcover albedo feedback for a 2% solar constant increase or decrease, with Southern Hemisphere cryosphere feedback being 2–5 times stronger than Northern Hemisphere cryosphere feedback.In the absence of changes in ice extent, changes in ice thickness in response to an increase in solar constant are associated with an increase in summer surface melting which is exactly balanced by increased basal winter freezing, and a reduction in the upward ocean-air flux in summer which is exactly balanced by an increased flux in winter, with no change in the annual mean ocean-air flux. Changes in the mean annual ocean-air heat flux require changes in mean annual ice extent, and are constrained to equal the change in meridional oceanic heat flux convergence in equilibrium. Feedback between ice extent and the meridional oceanic heat flux obtained by scaling the oceanic heat diffusion coefficient by the ice-free fraction regulates the feedback between ice extent and mean annual air-sea heat fluxes in polar regions, and has a modest effect on model-simulated high latitude temperature change.Accounting for the partial masking effect of vegetation on snow-covered land reduces the Northern Hemisphere mean temperature response to a 2% solar constant decrease or increase by 20% and 10%, respectively, even though the radiative forcing change caused by land snowcover changes is about 3 times larger in the absence of vegetational masking. Two parameterizations of the tundra fraction are tested: one based on mean annual land air temperature, and the other based on July land air temperature. The enhancement of the mean Northern Hemisphere temperature response to solar constant changes when the forest-tundra ecotone is allowed to shift with climate is only 1/3 to 1/2 that obtained by Otterman et al. (1984) when the mean annual parameterization is used here, and only 1/4 to 1/3 as large using the July parameterization.The parameterized temperature dependence of ice and snow albedo is found to enhance the global mean temperature response to a 2% solar constant increase by only 0.04 °C, in sharp contrast to the results of Washington and Meehl (1986) obtained with a mean annual model. However, there are significant differences in the method used here and in Washington and Meehl to estimate the importance of this feedback process. When their approach is used in a mean annual version of the present model, closer agreement to their results is obtained. 相似文献
20.
不同升温阈值下中国地区极端气候事件变化预估 总被引：6，自引：1，他引：5
本文基于耦合模式比较计划第五阶段(CMIP5)的18个全球气候模式的模拟结果,预估了全球平均气温在不同典型浓度路径(RCPs)下达到2℃、3℃和4℃阈值时,中国地区气温和降水的变化,并采用了具有稳定统计意义的27个极端气候指标定量评估了全球平均气温达到不同阈值时,中国地区极端气候事件的可能变化。结果表明,未来我国平均气温增幅将高于全球平均增暖,极端暖事件(如暖夜、暖昼、热带夜)明显增多,达到4℃阈值时,暖夜指数相比参考时段增加约49.9%。极端冷事件(如冷夜、冷昼、霜冻)减少。随全球气温升高,中国北方平均降水增多。在不同升温阈值下,中国地区降水的极端性都体现出增强的趋势,强降水事件发生频率(如中雨日数、大雨日数)和强度(如五日最大降水量、极端强降水量)都明显增加。随升温阈值的升高,这些变化幅度更大,在 RCP8.5 情景下全球升温 3℃和4℃时,中国平均五日最大降水分别增加 12.5mm和17.0mm。我国西南地区极端降水强度的增幅高于其他地区。 相似文献