Impact of Vertical Resolution on ENSO Teleconnection Simulation
JIANG Wei
WANG Wuke
ZHAO Shuyun
WANG Hongyue
ZHU Jintao
Abstract：Model resolution significantly influences the simulation effect of climate models.However,model vertical resolution has not been a primary focus in current model development.To evaluate the importance of model vertical resolution in climate modeling,this study took the El Niño-Southern Oscillation(ENSO)teleconnection as an example and explored the impact of different vertical resolution settings in the Community Earth System Model(CESM)on the simulation of ENSO teleconnections in the stratosphere and the troposphere.The results show that increasing vertical resolution can significantly boost the model's capability to simulate ENSO teleconnection.Based on the fifth generation reanalysis(ERA5)dataset from the European Centre for Medium-Range Weather Forecasts,the present study explored the effect of ENSO on zonal mean temperature and found a'negative-positive-negative'tripole mode in winter over the mid-to-high latitudes in the Northern Hemisphere.The CESM model with default vertical resolution(66 vertical levels,L66)failed in simulating this mode,while the model with higher vertical resolution(103 vertical levels,L103)performed better in capturing this mode.For the horizontal distribution of ENSO teleconnection,the tropospheric signal of ENSO simulated by L66 was stronger than that indicated by the reanalysis data,whereas the signal in L103 was significantly improved.The L103 model also simulated a more accurate ENSO teleconnection in the stratosphere compared to L66.Further analysis shows that the planetary waves simulated by L103 propagated more robustly from the troposphere to the stratosphere,which was more consistent with the ERA5 reanalysis data.Overall,improving vertical resolution can significantly improve the simulation of atmospheric wave activities and the stratosphere-troposphere dynamic coupling,which should be prioritized in model development.
Keywords：model vertical resolutionclimate effect of ENSOstratosphere-tropospheric coupling
Publication Date：2024-06-28
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：14( 477-490 )