宁夏南北气候差异大，与生态息息相关的降水空间分布特征演变及其影响因素需要更加细致深入的分析，本文选取1961—2022年宁夏20个国家气象站汛期降水、NCEP/NCAR大气再分析、海温及北极海冰资料，利用气候统计诊断方法，建立了宁夏汛期降水南北异常指标，探究太平洋海温和北极海冰强迫信号协同作用对其异常的可能影响。结果表明：宁夏汛期降水南北反位相特征分量呈明显的年代际变化，新年代际背景下典型“北涝南旱”分布型相比于1991年以前频次明显增加，南北反位相分布型出现比重增大，且南北差异愈发明显。太平洋海温（I_sst）和北极海冰（I_ice）关键区指标的协同（符号一致）和拮抗（符号相反）作用，造成乌拉尔山、贝加尔湖及鄂霍茨克海附近的位势高度异常，使得冷空气影响路径以及水汽输送位置不同。当I_sst和I_ice同为正时，宁夏汛期容易出现“南涝北旱”分布型，主要以南区偏多、北区偏少和南区偏多程度大于北区为主；当I_sst为正、I_ice为负时，容易出现“北涝南旱”分布型，尤其以北区偏多、南区偏少为主；当I_sst和I_ice同为负时，容易出现“北涝南旱”分布型，以北区偏多、南区偏少和北区偏少程度小于南区为主；当I_sst为负、I_ice为正时，以南区、北区均偏少为主。

There are significant climate differences between the north and south of Ningxia; however, the evolution characteristics and factors influencing precipitation spatial patterns closely related to ecology require more detailed and in-depth analysis. Using climate statistical diagnostic methods, this research examines precipitation data during the flood season for 20 meteorological stations in Ningxia, NCEP/NCAR atmospheric reanalysis, sea surface temperature and Arctic sea ice data from 1961 to 2022. An abnormal index for the north-south pattern of precipitation during the flood season in Ningxia was identified and explored the possible impact of the synergy of Pacific sea surface temperature and Arctic sea ice signals driving this anomaly. The results show that the characteristic components of the north-south reverse phase of precipitation during the flood season in Ningxia have significant interdecadal variations. The frequency of the typical “northern flood and southern drought” distribution patterns increased significantly in the recent interdecadal background compared with before 1991, the proportion of the north-south reverse phase distribution pattern increased, and the north-south difference become more obvious. The synergistic (consistent phase) and antagonistic (opposite phase) effects of key indicators of Pacific sea surface temperature (I_sst) and Arctic sea ice (I_ice) cause abnormal geopotential heights over the Ural Mountains, Lake Baikal, and the Okhotsk Sea, resulting in different impact paths of cold air and positions of water vapor transport. When I_sst and I_ice are both positive, Ningxia is prone to the distribution pattern of “southern flooding and northern drought” during the flood season, characterized mainly by more precipitation in the southern region, less in the northern region, and more in the southern region than in the northern region. When I_sst is positive and I_ice is negative, the “northern flooding and southern drought” distribution pattern is likely to occur, especially when the northern region has more precipitation and the southern region has less. When I_sst and I_ice are both negative, the “northern flooding and southern drought” distribution pattern was likely to occur, mainly because of more precipitation in the northern region, less precipitation in the southern region, and less precipitation in the northern region compared with the southern region. When I_sst is negative and I_ice is positive, this was mainly due to the precipitation in the southern and northern regions being lower.