Based on the high-and low-resolution Community Earth System Model, version 1(CESM1), and corresponding simulations from phase 6 of the Coupled Model Intercomparison Project(CMIP6), we compare the interannual variabili...Based on the high-and low-resolution Community Earth System Model, version 1(CESM1), and corresponding simulations from phase 6 of the Coupled Model Intercomparison Project(CMIP6), we compare the interannual variability of the East Asian summer monsoon(EASM). The EASM interannual variability is characterized by the anomalous western North Pacific anticyclone(WNPAC) circulation and the dipole rainfall pattern with a negative southern lobe over the western North Pacific and a positive northern lobe along the Meiyu–Baiu region, which is better reproduced by the highresolution models. The reason for the improvement in the high-resolution models has been attributed to the better simulation of the warm temperature advection from the wind anomalies on the climatological temperature gradient. Positive sea surface temperature(SST) anomalies over the tropical Indian Ocean are the key to the improved wind anomalies featuring a WNPAC in the high-resolution models. The warm SST anomalies over the tropical Indian Ocean strengthen the WNPAC by triggering a Kelvin-wave response to the enhanced heat release induced by the increased precipitation. Based on the mixed-layer heat budget analysis, the warm SST anomalies over the western Indian Ocean in the high-resolution CESM1 are tied to the anomalous easterly wind along the equator, which reduces surface evaporation and upwelling.Therefore, the better simulations of air–sea feedback and the oceanic mesoscale eddy over the western Indian Ocean are the key for the improved simulation of the EASM interannual variations in the high-resolution CESM1.展开更多
In the present study, the LASG/IAP Climate system Ocean Model version 2 （LICOM2） was implemented to replace the original ocean component in the Community Earth System Model version 1.0.4 （CESM1） to form a new coup...In the present study, the LASG/IAP Climate system Ocean Model version 2 （LICOM2） was implemented to replace the original ocean component in the Community Earth System Model version 1.0.4 （CESM1） to form a new coupled model referred to as CESMI＋LICOM2. The simulation results from a 300-yr prein- dustrial experiment by using this model were evaluated against both observations and the Flexible Global Ocean-Atmosphere-Land System Model with grid-atmospheric model version 2 （FGOALS-g2）. It was found that CESMI＋LICOM2 simulates well the mean features of the ocean, sea ice, and atmosphere, relative to models used in the Coupled Model Intercomparison Experiment （CMIP5）, when compared with obser- vations. The spatial distribution of SST bias in CESMI＋LICOM2 is similar to that in the Community Climate System Model version 4 （CCSM4）. The simulated climate variabilities, such as ENSO and Pacific decadal oscillation, are also reasonably simulated when compared with observations. The successful implementation of LICOM2 in the CESM1 framework greatly enhances the capability of LICOM2 in conducting high-resolution simulations and model tuning. Compared with FGOALS-g2, the simulations of both SST and Atlantic meridional overturning circulation are significantly improved in CESMI^LICOM2. The former can be mainly attributed to the atmospheric model, and the latter to the improvement in the parameterization of diapycnal mixing. The study provides a base to further improve the present version of LICOM and its functionalities in the coupled model FGOALS at both low and high resolutions.展开更多
基金supported by the National Natural Science Foundation of China [Grant Nos.42275018 (L.D.) and 42175029 (F.S.)]the Shandong Provincial Natural Science Fund for Excellent Young Scientists Fund Program (Overseas) [Grant No.2022HWYQ-065 (L.D.)]+3 种基金the Taishan Scholars Program of Shandong Province [Grant No.tsqn202211068 (L.D.)]the Fund of Laoshan Laboratory [Grant Nos.LSKJ202202602 (L.D.) and LSKJ202202201 (F.S.)]financially supported by Laoshan Laboratory (Grant No.LSKJ202300302)supported by the Office of Science, U.S.Department of Energy (DOE) Biological and Environmental Research through the Water Cycle and Climate Extremes Modeling (WACCEM) scientific focus area funded by the Regional and Global Model Analysis program area。
文摘Based on the high-and low-resolution Community Earth System Model, version 1(CESM1), and corresponding simulations from phase 6 of the Coupled Model Intercomparison Project(CMIP6), we compare the interannual variability of the East Asian summer monsoon(EASM). The EASM interannual variability is characterized by the anomalous western North Pacific anticyclone(WNPAC) circulation and the dipole rainfall pattern with a negative southern lobe over the western North Pacific and a positive northern lobe along the Meiyu–Baiu region, which is better reproduced by the highresolution models. The reason for the improvement in the high-resolution models has been attributed to the better simulation of the warm temperature advection from the wind anomalies on the climatological temperature gradient. Positive sea surface temperature(SST) anomalies over the tropical Indian Ocean are the key to the improved wind anomalies featuring a WNPAC in the high-resolution models. The warm SST anomalies over the tropical Indian Ocean strengthen the WNPAC by triggering a Kelvin-wave response to the enhanced heat release induced by the increased precipitation. Based on the mixed-layer heat budget analysis, the warm SST anomalies over the western Indian Ocean in the high-resolution CESM1 are tied to the anomalous easterly wind along the equator, which reduces surface evaporation and upwelling.Therefore, the better simulations of air–sea feedback and the oceanic mesoscale eddy over the western Indian Ocean are the key for the improved simulation of the EASM interannual variations in the high-resolution CESM1.
基金Supported by the National(Key)Basic Research and Development(973)Program of China(2013CB956204 and 2010CB951800)National Natural Science Foundation of China(41376019)Strategic Priority Research Program of the Chinese Academy of Sciences(XDA11010304)
文摘In the present study, the LASG/IAP Climate system Ocean Model version 2 （LICOM2） was implemented to replace the original ocean component in the Community Earth System Model version 1.0.4 （CESM1） to form a new coupled model referred to as CESMI＋LICOM2. The simulation results from a 300-yr prein- dustrial experiment by using this model were evaluated against both observations and the Flexible Global Ocean-Atmosphere-Land System Model with grid-atmospheric model version 2 （FGOALS-g2）. It was found that CESMI＋LICOM2 simulates well the mean features of the ocean, sea ice, and atmosphere, relative to models used in the Coupled Model Intercomparison Experiment （CMIP5）, when compared with obser- vations. The spatial distribution of SST bias in CESMI＋LICOM2 is similar to that in the Community Climate System Model version 4 （CCSM4）. The simulated climate variabilities, such as ENSO and Pacific decadal oscillation, are also reasonably simulated when compared with observations. The successful implementation of LICOM2 in the CESM1 framework greatly enhances the capability of LICOM2 in conducting high-resolution simulations and model tuning. Compared with FGOALS-g2, the simulations of both SST and Atlantic meridional overturning circulation are significantly improved in CESMI^LICOM2. The former can be mainly attributed to the atmospheric model, and the latter to the improvement in the parameterization of diapycnal mixing. The study provides a base to further improve the present version of LICOM and its functionalities in the coupled model FGOALS at both low and high resolutions.
