耦合模式中潮汐对北大西洋模拟的影响研究

将8个主要平衡分潮加入到耦合模式中，对比研究潮汐对北大西洋模拟影响。由于潮汐的引入，模式模拟SST在北大西洋中纬度区域偏差显著减小，高纬度区域SST降温明显。SST模拟的改变使潮汐试验的海表净热通量模拟误差下降了约30%，但高纬度海冰显著增加。模式中引入潮汐对北大西洋上层环流，尤其是西边界流的路径模拟改进显著，这是SST及海表净热通量模拟改变的主要原因。同时，北大西洋上层和深层西边界流在潮汐的作用下，都表现出环流减弱的特点，这也使得大西洋经向翻转环流在26.5°N处上层2 km的输送减弱，与观测数据更为接近。较弱的大西洋经向翻转环流导致海洋热量在中低纬度聚集而无法输送到高纬度区域，这是造成潮汐试验模拟的海温在中低纬度偏高、高纬度偏低的原因，较弱的热输送也同时导致了潮汐试验中北半球海冰面积增加。

Influence of Tidal Forcing on North Atlantic Simulation in a Coupled Climate Model

The eight main tide constituents have been implemented into a coupled climate model to investigate the influence of tidal forcing on North Atlantic simulation. When implementing the tidal forcing, the bias in SST simulation in the middle latitudes significantly reduces, and the simulated SST in high latitudes becomes cooler. The above changes in SST simulation lead to decrease by about 30% in the bias of simulated net sea surface heat flux with tidal forcing. However, the sea ice increases obviously. The pathway of North Atlantic circulations, especially the western boundary current has been simulated fairly better due to the tidal forcing. This is the major reason for the improvements of SST and net sea surface heat flux simulation. Transports of the upper North Atlantic and deep boundary current both decrease with tidal forcing. Compared with observation data, the transport of Atlantic meridional overturning circulation (AMOC) in the tide experiment is captured well in the upper 2000 m at 26.5°N. The lower transport of AMOC leads to less poleward heat transport with tidal forcing. This is the reason why temperature becomes warmer in the lower and middle latitudes and cooler in the high latitudes in the tide experiment. The sea ice also increases by 40% in the Northern Hemisphere.