CAJ | 학술논문

山脉力矩是大气轴向角动量变化的主要外部因子之一，是研究地球运动和大气相互作用的关键变量。利用NCEP/NCAR第一套再分析资料计算了1948-2011年的全球山脉力矩，定量分析了全球山脉力矩的时空变化趋势及其与地球自转速率（以日长表示）的关系。研究表明，近64年山脉力矩变化最为显著的地区集中在青藏高原和南美的安第斯山脉，青藏高原东西两侧的山脉力矩具有不同的变化趋势。滞后相关分析显示，全球山脉力矩与日长的相关系数在日长滞后5年时达到最大（滞后相关系数为-0.482），而南美安第斯山和青藏高原的山脉力矩则分别于日长滞后2年和9年时达到最大（滞后相关系数分别为-0.461和-0.689），因此山脉力矩的变化早于日长变化。从年代际变化看，全球积分的山脉力矩和南亚高压强度指数趋势上基本一致，可以作为表征天气、气候变化的一个强信号。
산맥력구시대기축향각동량변화적주요외부인자지일，시연구지구운동화대기상호작용적관건변량。이용NCEP/NCAR제일투재분석자료계산료1948-2011년적전구산맥력구，정량분석료전구산맥력구적시공변화추세급기여지구자전속솔（이일장표시）적관계。연구표명，근64년산맥력구변화최위현저적지구집중재청장고원화남미적안제사산맥，청장고원동서량측적산맥력구구유불동적변화추세。체후상관분석현시，전구산맥력구여일장적상관계수재일장체후5년시체도최대（체후상관계수위-0.482），이남미안제사산화청장고원적산맥력구칙분별우일장체후2년화9년시체도최대（체후상관계수분별위-0.461화-0.689），인차산맥력구적변화조우일장변화。종년대제변화간，전구적분적산맥력구화남아고압강도지수추세상기본일치，가이작위표정천기、기후변화적일개강신호。
Mountain torque is an important external factor inlfuencing the dynamics of axial atmospheric angular momentum and it also plays a major role in the interaction between the Earth and the atmosphere. Using the data from NCEP/NCAR reanalysisⅠ, the daily global mountain torque during the period from 1948 to 2011 is calculated. Spatial and temporal variations of mountain torque and its relations to variations of earth rotation rate (denoted as length of day, LOD) are further discussed. It is shown that Tibetan Plateau located in East Asia and the Andes located in South America are two main areas with signiifcant mountain torque change during the past 64 years. Mountain torque at east and south sides of Tibetan Plateau has different trends. Moreover, mountain torque and LOD are lag correlated. Maximal correlation occurred respectively when global mountain torque leads LOD ifve years (R=-0.482), Andes Mountain torque leads LOD two years (R=-0.461) and Tibetan Plateau mountain torque leads LOD nine years (R=-0.689), suggesting that mountain torque forces LOD anomalies. On a decadal scale, global mountain torque has a similar trend with intensity index of South Asian High, indicating that mountain torque can be a very useful signal for climate change.