CMIP5模式对西北太平洋SST的模拟偏差及可能成因分析     

王晨琦  邹立维  周天军 《中国科学:地球科学》2018,(6)

利用参加第五次国际耦合模式比较计划(Coupled Model Inter-comparison Project Phase 5,CMIP5)的21个全球耦合气候模式的输出结果,利用海表热收支诊断方法,讨论了CMIP5模式对西北太平洋海表面温度(SST)的模拟偏差及其可能成因.结果表明,大部分CMIP5模式模拟的西北太平洋SST在全年都有持续的冷偏差,且在夏季最大,在冬季最小.CMIP5模式模拟的西北太平洋SST冷偏差是海盆尺度的,并且主要分布在中低纬度海洋内区.混合层热收支诊断分析研究表明,大气过程所致的海表净热通量模拟偏少是造成西北太平洋SST模拟冷偏差的主要原因,其中大气过程导致的潜热通量模拟偏多是造成冬、春、秋三季SST模拟冷偏差的最主要因素,而在夏季海表短波辐射模拟偏少和潜热模拟偏多对SST模拟冷偏差均有重要贡献.进一步分析表明,冬、春季西北太平洋低层风速偏大可能与海洋大陆区域的正降水偏差有关,而夏、秋季风速偏差则可能与热带辐合带的模拟偏差有关.冬、春季海洋大陆区域的正降水异常及夏、秋季ITCZ的模拟偏差使得北太平洋地区产生东北风异常,该东北风异常叠加在气候态风场上,使得北太平洋地区风速增强,造成海表潜热通量模拟偏多,海温模拟偏冷.  相似文献   

对流层和平流层温度中ENSO信号的多种资料比较   总被引：2，自引：0，他引：2       下载免费PDF全文

于超越  周天军  李博 《大气科学》2011,35(6):1020-1032

本文利用1980～1999年卫星资料Microwave Sounding Unit (MSU)和5种再分析资料(ERA40、JRA25、NCEP1、NCEP2、MERRA),分析了北半球冬季全球对流层中层和平流层低层温度变化中的ENSO信号,讨论了ENSO暖冷位相时温度异常的对称性和非对称性,并以MSU卫星资料为标准,...  相似文献   

东亚副热带西风急流及其年际变率的海气耦合模式模拟   总被引：6，自引：0，他引：6  

蔡琼琼  周天军  吴波  李博  张丽霞 《海洋学报》2011,33(4):38-48

分析了中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室(LASG/IAP)快速耦合气候系统模式FGOALS_gl模拟的东亚副热带西风急流,并讨论了ENSO对东亚夏季副热带西风急流位置的影响.FGOALS_gl能较好模拟东亚副热带西风急流的空间分布以及季节演变,但较之再分析资料,模式模拟的急流强度偏弱...  相似文献   

Uncertainty in the 2°C warming threshold related to climate sensitivity and climate feedback     

周天军  陈晓龙 《Acta Meteorologica Sinica》2015,29(6):884-895

Climate sensitivity is an important index that measures the relationship between the increase in greenhouse gases and the magnitude of global warming. Uncertainties in climate change projection and climate modeling are mostly related to the climate sensitivity. The climate sensitivities of coupled climate models determine the magnitudes of the projected global warming. In this paper, the authors thoroughly review the literature on climate sensitivity, and discuss issues related to climate feedback processes and the methods used in estimating the equilibrium climate sensitivity and transient climate response (TCR), including the TCR to cumulative CO₂ emissions. After presenting a summary of the sources that affect the uncertainty of climate sensitivity, the impact of climate sensitivity on climate change projection is discussed by addressing the uncertainties in 2°C warming. Challenges that call for further investigation in the research community, in particular the Chinese community, are discussed.  相似文献   

Variation of surface temperature during the last millennium in a simulation with the FGOALS-gl climate system model     

张洁  周天军  辛晓歌 《大气科学进展》2013,30(3):699-712

A reasonable past millennial climate simulation relies heavily on the specified external forcings, including both natural and anthropogenic forcing agents. In this paper, we examine the surface temperature responses to specified external forcing agents in a millennium-scale transient climate simulation with the fast version of LASG IAP Flexible Global Ocean-Atmosphere-Land System model (FGOALS-gl) developed in the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics (LASG/IAP). The model presents a reasonable performance in comparison with reconstructions of surface temperature. Differentiated from significant changes in the 20th century at the global scale, changes during the natural-forcing-dominant period are mainly manifested in the Northern Hemisphere. Seasonally, modeled significant changes are more pronounced during the wintertime at higher latitudes. This may be a manifestation of polar amplification associated with sea-ice-temperature positive feedback. The climate responses to total external forcings can explain about half of the climate variance during the whole millennium period, especially at decadal timescales. Surface temperature in the Antarctic shows heterogeneous and insignificant changes during the preindustrial period and the climate response to external forcings is undetectable due to the strong internal variability. The model response to specified external forcings is modulated by cloud radiative forcing (CRF). The CRF acts against the fluctuations of external forcings. Effects of clouds are manifested in shortwave radiation by changes in cloud water during the natural-forcing-dominant period, but mainly in longwave radiation by a decrease in cloud amount in the anthropogenic-forcing-dominant period.  相似文献   

Relationships between the East Asian-western north pacific monsoon and ENSO simulated by FGOALS-s2   总被引：4，自引：1，他引：3  

吴波  周天军 《大气科学进展》2013,30(3):713-725

The relationships between ENSO and the East Asian-western North Pacific monsoon simulated by the Flexible Global Ocean-Atmosphere-Land System model, Spectral Version 2 (FGOALS-s2), a state-of-the-art coupled general circulation model (CGCM), are evaluated. For El Nio developing summers, FGOALS-s2 reproduces the anomalous cyclone over the western North Pacific (WNP) and associated negative precipitation anomalies in situ. In the observation, the anomalous cyclone is transformed to an anomalous anticyclone over the WNP (WNPAC) during El Nio mature winters. The model reproduces the WNPAC and associated positive precipitation anomalies over southeastern China during winter. However, the model fails to simulate the asymmetry of the wintertime circulation anomalies over the WNP between El Nio and La Nia. The simulated anomalous cyclone over the WNP (WNPC) associated with La Nia is generally symmetric about the WNPAC associated with El Nio, rather than shifted westward as that in the observation. The discrepancy can partially explain why simulated La Nin a events decay much faster than observed. In the observation, the WNPAC maintains throughout the El Nio decaying summer under the combined effects of local forcing of the WNP cold sea surface temperature anomaly (SSTA) and remote forcing from basinwide warming in the tropical Indian Ocean. FGOALS-s2 captures the two mechanisms and reproduces the WNPAC throughout the summer. However, owing to biases in the mean state, the precipitation anomalies over East Asia, especially those of the Meiyu rain belt, are much weaker than that in the observation.  相似文献   

The flexible global ocean-atmosphere-land system model, Grid-point Version 2: FGOALS-g2   总被引：3，自引：0，他引：3  

李立娟  林鹏飞  俞永强  王斌  周天军  刘利  刘骥平  包庆  徐世明  黄文誉  夏坤  普业  董理  申思  刘屹岷  胡宁  刘咪咪  孙文奇  史湘军  郑伟鹏  吴波  宋米荣  刘海龙  张学洪  吴国雄  薛巍  黄小猛  杨广文  宋振亚  乔方利 《大气科学进展》2013,30(3):543-560

This study mainly introduces the development of the Flexible Global Ocean-Atmosphere-Land System Model: Grid-point Version 2 (FGOALS-g2) and the preliminary evaluations of its performances based on results from the pre-industrial control run and four members of historical runs according to the fifth phase of the Coupled Model Intercomparison Project (CMIP5) experiment design. The results suggest that many obvious improvements have been achieved by the FGOALS-g2 compared with the previous version,FGOALS-g1, including its climatological mean states, climate variability, and 20th century surface temperature evolution. For example,FGOALS-g2 better simulates the frequency of tropical land precipitation, East Asian Monsoon precipitation and its seasonal cycle, MJO and ENSO, which are closely related to the updated cumulus parameterization scheme, as well as the alleviation of uncertainties in some key parameters in shallow and deep convection schemes, cloud fraction, cloud macro/microphysical processes and the boundary layer scheme in its atmospheric model. The annual cycle of sea surface temperature along the equator in the Pacific is significantly improved in the new version. The sea ice salinity simulation is one of the unique characteristics of FGOALS-g2, although it is somehow inconsistent with empirical observations in the Antarctic.  相似文献   

Impacts of two types of El Niño on atmospheric circulation in the Southern Hemisphere     

孙丹  薛峰  周天军 《大气科学进展》2013,30(6):1732-1742

Based on NCEP/NCAR （National Centers for Environmental Prediction/National Center for Atmo- spheric Research） reanalysis data from 1979 to 2010, the impacts of two types of E1 Nino on atmospheric circulation in the Southern Hemisphere （SH） are analyzed. It is shown thaL when a warming event occurs in the equatorial eastern Pacific （EP E1 Nino）, there is a negative sea level pressure （SLP） anomaly in the east- ern Pacific and a positive one in the western Pacific. Besides, there exists a negative anomaly between 40°S and 60°S and a positive anomaly to the south of 60°S. When a warming event in the central Pacific （CP E1 Nino） occurs, there appears a negative SLP anomaly in the central Pacific and a positive SLP anomaly in the eastern and western Pacific, but the SLP anomalies are not so evident in the SH extratropics. In particular, the Pacific-South America （PSA） pattern induced by the CP E1 Nino is located more northwestward, with a weaker anomaly compared with the EP E1 Nino. This difference is directly related with the different position of heating centers associated with the two types of E1 Nino events. Because the SST anomaly associated with CP E1 Nino is located more westward than that associated with EP El Nino, the related heating center tends to move westward and the response of SH atmospheric circulation to the tropical heating changes accordingly, thus exciting a different position of the PSA pattern. It is also noted that the local meridional cell plays a role in the SH high latitudes during EP E1 Nino. The anomalous ascending motion due to the enhancement of convection over the eastern Pacific leads to an enhancement of the local Hadley cell and the meridional cell in the middle and high latitudes, which in turn induces an anomalous descending motion and the related positive anomaly of geopotential height over the Amundsen-Bellingshausen Sea.  相似文献   

区域海气耦合模式研究进展   总被引：4，自引：0，他引：4  

邹立维  周天军 《地球科学进展》2012,27(8):857-865

区域海气耦合模式是进行区域尺度气候模拟和预估的重要工具,近年来得到快速发展。在阐述区域海气耦合过程重要性的基础上,对当今国内外主要的区域海气耦合模式研究进展进行总结,归纳区域海气耦合模拟所关注的核心科学问题,介绍区域海气耦合模式的技术特点。发展基于耦合器且无通量订正的区域海气耦合模式是区域海气耦合模式发展的主流方向。当前国际上区域海气耦合模拟所关注的主要科学问题,包括区域海气耦合模式对区域海洋过程的模拟、区域海气耦合模式对区域大气过程的模拟、亚洲—西北太平洋季风模拟及其耦合模拟海表面温度(SST)冷偏差问题、热带海气相互作用过程模拟,以及区域海气耦合模式对未来气候变化的预估研究等。对上述5个方面科学问题的研究思路和主要科学结论进行总结,重点关注针对亚洲—西北太平洋季风区的区域海气耦合模拟研究,对区域海气耦合过程改进亚洲—西北太平洋地区降水模拟的物理机制,及在该区域模拟SST冷偏差的成因亦进行相关归纳和总结。最后提出当前区域海气耦合模拟亟待解决的关键科学问题。  相似文献   

气候系统模式FGOALS_gl模拟的赤道太平洋年际变率   总被引：4，自引：1，他引：3  

满文敏  周天军  张丽霞 《大气科学》2010,34(6):1141-1154

本文分析了中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室 (LASG/IAP) 发展的气候系统模式FGOALS_gl对赤道太平洋年际变率的模拟能力。结果表明, FGOALS_gl可以较好地模拟出赤道太平洋SST异常年际变率的主要特征, 但模拟的ENSO事件振幅偏大, 且变率周期过于规则。耦合模式模拟的气候平均风应力在热带地区比ERA40再分析资料的风应力强度偏弱30%左右, 由此引起的海洋平均态的变化, 是造成模拟的ENSO振幅偏强的主要原因。FGOALS_gl模拟的ENSO峰值多出现在春季或夏季, 原因可归之于模式模拟的SST季节循环偏差。耦合模式可以合理再现ENSO演变过程, 但观测中SST异常的东传特征在模式中没有得到再现, 这与模拟的ENSO发展模态表现为单一的 “SST模态” 有关。模拟的ENSO位相转换机制与 “充电—放电” 概念模型相符合, 赤道太平洋热含量的变化是维持ENSO振荡的机制。在ENSO暖位相时期, 赤道中东太平洋与印度洋—西太平洋暖池区的海平面气压距平型表现为南方涛动型 (SO型), 200 hPa位势高度分布表现为太平洋—北美遥相关型 (PNA型)。  相似文献