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The Impact of Low-Level Cloud over the Eastern Subtropical Pacific on the "Double ITCZ" in LASG FGCM-0


doi: 10.1007/BF02690804

  • Like many other coupled models, the Flexible coupled General Circulation Model (FGCM-0) suffersfrom the spurious "Double ITCZ". In order to understand the "Double ITCZ" in FGCM-0, this study firstexamines the low-level cloud cover and the bulk stability of the low troposphere over the eastern subtropicalPacific simulated by the National Center for Atmospheric Research (NCAR) Community Climate Modelversion 3 (CCM3), which is the atmosphere component model of FGCM-0. It is found that the bulkstability of the low troposphere simulated by CCM3 is very consistent with the one derived from theNational Center for Environmental Prediction (NCEP) reanalysis, but the simulated low-level cloud coveris much less than that derived from the International Satellite Cloud Climatology Project (ISCCP) D2data. Based on the regression equations between the low-level cloud cover from the ISCCP data and thebulk stability of the low troposphere derived from the NCEP reanalysis, the parameterization scheme otlow-level cloud in CCM3 is modified and used in sensitivity experiments to examine the impact of low-levelcloud over the eastern subtropical Pacific on the spurious "Double ITCZ" in FGCM-0. Results show thatthe modified scheme causes the simulated low-level cloud cover to be improved locally over the cold oceans.Increasing the low-level cloud cover off Peru not only significantly alleviates the SST warm biases in thesoutheastern tropical Pacific, but also causes the equatorial cold tongue to be strengthened and to extendfurther west. Increasing the low-level cloud fraction off California effectively reduces the SST warm biasesin ITCZ north of the equator. In order to examine the feedback between the SST and low-level cloudcover off Peru, one additional sensitivity experiment is performed in which the SST over the cold ocean offPeru is restored. It shows that decreasing the SST results in similar impacts over the wide regions fromthe southeastern tropical Pacific northwestwards to the western/central equatorial Pacific as increasing thelow-level cloud cover does.
  • [1] DAI Fushan, YU Rucong, ZHANG Xuehong, YU Yongqiang, LI Jianglong, 2005: Impacts of an Improved Low-Level Cloud Scheme on the Eastern Pacific ITCZ-Cold Tongue Complex, ADVANCES IN ATMOSPHERIC SCIENCES, 22, 559-574.  doi: 10.1007/BF02918488
    [2] LIU Zhengyu, WU Shu, ZHANG Shaoqing, LIU Yun, RONG Xinyao, , 2013: Ensemble Data Assimilation in a Simple Coupled Climate Model: The Role of Ocean-Atmosphere Interaction, ADVANCES IN ATMOSPHERIC SCIENCES, 30, 1235-1248.  doi: 10.1007/s00376-013-2268-z
    [3] LIU Xiangcui, LIU Hailong, 2014: Heat Budget of the South-Central Equatorial Pacific in CMIP3 Models, ADVANCES IN ATMOSPHERIC SCIENCES, 31, 669-680.  doi: 10.1007/s00376-013-2299-5
    [4] LI Lijuan, WANG Bin, Yuqing WANG, Hui WAN, 2007: Improvements in Climate Simulation with Modifications to the Tiedtke Convective Parameterization in the Grid-Point Atmospheric Model of IAP LASG (GAMIL), ADVANCES IN ATMOSPHERIC SCIENCES, 24, 323-335.  doi: 10.1007/s00376-007-0323-3
    [5] FU Weiwei, ZHOU Guangqing, WANG Huijun, 2006: Modeling the Tropical Pacific Ocean Using a Regional Coupled Climate Model, ADVANCES IN ATMOSPHERIC SCIENCES, 23, 625-638.  doi: 10.1007/s00376-006-0625-x
    [6] Zeng Qingcun, Dai Yongjiu, Xue Feng, 1998: Simulation of the Asian Monsoon by IAP AGCM Coupled with an Advanced Land Surface Model (IAP94), ADVANCES IN ATMOSPHERIC SCIENCES, 15, 1-16.  doi: 10.1007/s00376-998-0013-9
    [7] LIAO Zhijie, ZHANG Yaocun, 2013: Simulation of a Persistent Snow Storm over Southern China with a Regional Atmosphere-Ocean Coupled Model, ADVANCES IN ATMOSPHERIC SCIENCES, 30, 425-447.  doi: 10.1007/s00376-012-2098-4
    [8] Shuwen ZHAO, Yongqiang YU, Pengfei LIN, Hailong LIU, Bian HE, Qing BAO, Yuyang GUO, Lijuan HUA, Kangjun CHEN, Xiaowei WANG, 2021: Datasets for the CMIP6 Scenario Model Intercomparison Project (ScenarioMIP) Simulations with the Coupled Model CAS FGOALS-f3-L, ADVANCES IN ATMOSPHERIC SCIENCES, 38, 329-339.  doi: 10.1007/s00376-020-0112-9
    [9] Chang LIU, Shaoqing ZHANG, Shan LI, Zhengyu LIU, 2017: Impact of the Time Scale of Model Sensitivity Response on Coupled Model Parameter Estimation, ADVANCES IN ATMOSPHERIC SCIENCES, 34, 1346-1357.  doi: 10.1007/s00376-017-6272-6
    [10] Yu Yongqiang, Yu Rucong, Zhang Xuehong, Liu Hailong, 2002: A Flexible Coupled Ocean-Atmosphere General Circulation Model, ADVANCES IN ATMOSPHERIC SCIENCES, 19, 169-190.  doi: 10.1007/s00376-002-0042-8
    [11] LIU Xiying, ZHANG Xuehong, YU Yongqiang, YU Rucong, 2004: Mean Climatic Characteristics in High Northern Latitudes in an Ocean-Sea Ice-Atmosphere Coupled Model, ADVANCES IN ATMOSPHERIC SCIENCES, 21, 236-244.  doi: 10.1007/BF02915710
    [12] ZHENG Weipeng, YU Yongqiang, 2007: ENSO Phase-Locking in an Ocean-tmosphere Coupled Model FGCM-1.0, ADVANCES IN ATMOSPHERIC SCIENCES, 24, 833-844.  doi: 10.1007/s00376-007-0833-z
    [13] Dai Yongjiu, Xue Feng, Zeng Qingcun, 1998: A Land Surface Model (IAP94) for Climate Studies Part II: Implementation and Preliminary Results of Coupled Model with IAP GCM, ADVANCES IN ATMOSPHERIC SCIENCES, 15, 47-62.  doi: 10.1007/s00376-998-0017-5
    [14] SUN Jianqi, Joong Bae AHN, 2011: A GCM-Based Forecasting Model for the Landfall of Tropical Cyclones in China, ADVANCES IN ATMOSPHERIC SCIENCES, 28, 1049-1055.  doi: 10.1007/s00376-011-0122-8
    [15] Xinrong WU, Shaoqing ZHANG, Zhengyu LIU, 2016: Implementation of a One-Dimensional Enthalpy Sea-Ice Model in a Simple Pycnocline Prediction Model for Sea-Ice Data Assimilation Studies, ADVANCES IN ATMOSPHERIC SCIENCES, 33, 193-207.  doi: 10.1007/s00376-015-5099-2
    [16] LI Chaofan, LIN Zhongda, 2015: Predictability of the Summer East Asian Upper-Tropospheric Westerly Jet in ENSEMBLES Multi-Model Forecasts, ADVANCES IN ATMOSPHERIC SCIENCES, 32, 1669-1682.  doi: 10.1007/s00376-015-5057-z
    [17] Yuyang GUO, Yongqiang YU, Pengfei LIN, Hailong LIU, Bian HE, Qing BAO, Shuwen ZHAO, Xiaowei WANG, 2020: Overview of the CMIP6 Historical Experiment Datasets with the Climate System Model CAS FGOALS-f3-L, ADVANCES IN ATMOSPHERIC SCIENCES, 37, 1057-1066.  doi: 10.1007/s00376-020-2004-4
    [18] Bo AN, Yongqiang YU, Qing BAO, Bian HE, Jinxiao LI, Yihua LUAN, Kangjun CHEN, Weipeng ZHENG, 2022: CAS FGOALS-f3-H Dataset for the High-Resolution Model Intercomparison Project (HighResMIP) Tier 2, ADVANCES IN ATMOSPHERIC SCIENCES, 39, 1873-1884.  doi: 10.1007/s00376-022-2030-5
    [19] JIANG Dabang, WANG Huijun, LANG Xianmei, 2005: Evaluation of East Asian Climatology as Simulated by Seven Coupled Models, ADVANCES IN ATMOSPHERIC SCIENCES, 22, 479-495.  doi: 10.1007/BF02918482
    [20] JIANG Xiaoping, ZHONG Zhong, LIU Chunxia, 2008: The Effect of Typhoon-Induced SST Cooling on Typhoon Intensity: The Case of Typhoon Chanchu (2006), ADVANCES IN ATMOSPHERIC SCIENCES, 25, 1062-1072.  doi: 10.1007/s00376-008-1062-9

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Manuscript History

Manuscript received: 10 May 2003
Manuscript revised: 10 May 2003
通讯作者: 陈斌, bchen63@163.com
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The Impact of Low-Level Cloud over the Eastern Subtropical Pacific on the "Double ITCZ" in LASG FGCM-0

  • 1. LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029;Beijing Institute of Applied Meteorology, Beijing 100029,LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029,LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029,LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029,LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029;National Climate Center, Beijing 100081

Abstract: Like many other coupled models, the Flexible coupled General Circulation Model (FGCM-0) suffersfrom the spurious "Double ITCZ". In order to understand the "Double ITCZ" in FGCM-0, this study firstexamines the low-level cloud cover and the bulk stability of the low troposphere over the eastern subtropicalPacific simulated by the National Center for Atmospheric Research (NCAR) Community Climate Modelversion 3 (CCM3), which is the atmosphere component model of FGCM-0. It is found that the bulkstability of the low troposphere simulated by CCM3 is very consistent with the one derived from theNational Center for Environmental Prediction (NCEP) reanalysis, but the simulated low-level cloud coveris much less than that derived from the International Satellite Cloud Climatology Project (ISCCP) D2data. Based on the regression equations between the low-level cloud cover from the ISCCP data and thebulk stability of the low troposphere derived from the NCEP reanalysis, the parameterization scheme otlow-level cloud in CCM3 is modified and used in sensitivity experiments to examine the impact of low-levelcloud over the eastern subtropical Pacific on the spurious "Double ITCZ" in FGCM-0. Results show thatthe modified scheme causes the simulated low-level cloud cover to be improved locally over the cold oceans.Increasing the low-level cloud cover off Peru not only significantly alleviates the SST warm biases in thesoutheastern tropical Pacific, but also causes the equatorial cold tongue to be strengthened and to extendfurther west. Increasing the low-level cloud fraction off California effectively reduces the SST warm biasesin ITCZ north of the equator. In order to examine the feedback between the SST and low-level cloudcover off Peru, one additional sensitivity experiment is performed in which the SST over the cold ocean offPeru is restored. It shows that decreasing the SST results in similar impacts over the wide regions fromthe southeastern tropical Pacific northwestwards to the western/central equatorial Pacific as increasing thelow-level cloud cover does.

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