So, the zonal index can be defined as the difference in geopotential height between40° N and65° N. 西风环流的强弱不仅对北半球的气候有显著影响，对我国冬季的气温和降水也有显著关系。
Predicting East Coast Winter Storm Frequencies from Midtropospheric Geopotential Height Patterns. 从对流层中层位势型预报东海岸冬季风暴频率。
Geopotential height represents anticorrelation between the Antarctic pole region and tropic region. 总体上,南极位势高度与赤道位势高度有极其显著的负相关关系,北极与赤道的位势高度之间以及两极位势高度之间相关关系不显著;
The result shows that XISM02 as well as EIGEN1S and EIGEN2 yields a good fit to the geopotential field in Arctic area. 结果表明：XISM02模型在北极地区精度与EIGEN1S，EIGEN2相当。
