青藏高原地区1985~2010年大气热源变化特征分析

Analysis of the Variation Characteristics of Atmospheric Heat Source over the Qinghai-Xizang Plateau from 1985 to 2010

摘要: 基于1985~2010年青藏高原大气热源资料，采用趋势分析、EOF分解和M-K突变检验，系统分析了青藏高原大气热源强度的年际及季节变化特征。结果表明：研究时段内青藏高原大气热源强度总体呈增强趋势，但变化过程具有明显阶段性和波动性，年代际上表现为“20世纪80年代末震荡明显、90年代波动减弱、21世纪初小幅增强”的演变特征。季节上，夏季大气热源增强最为显著，且年代际振幅最大；春季整体呈波动减弱后增强的变化过程；秋季和冬季则以热汇背景下的缓慢增强为主，且秋季存在由热汇向热源转化的特征。EOF分析表明，第一模态主要反映长期变化趋势，第二模态则表征更强的年际波动与年代际调整，不同季节模态特征差异明显。M-K检验结果显示，年尺度及春夏季热源变化存在一定转折点，但整体突变特征不显著，说明青藏高原大气热源变化以渐进式调整为主。研究揭示了青藏高原大气热源的非线性演变规律及其显著季节差异，可为进一步认识高原热力异常及其气候效应提供参考。

Abstract: Based on data regarding the atmospheric heat source over the Qinghai-Xizang Plateau from 1985 to 2010, this study systematically analyzes the interannual and seasonal variation characteristics in the intensity of the atmospheric heat source using trend analysis, EOF decomposition, and the M-K abrupt change test. The results indicate that the intensity of the atmospheric heat source over the Qinghai-Xizang Plateau generally trended upward during the study period, though the process was characterized by distinct phases and fluctuations; interdecadal evolution was marked by significant oscillation in the late 1980s, dampened fluctuation in the 1990s, and a slight intensification in the early 21st century. Seasonally, the intensification of the atmospheric heat source was most pronounced in summer, which also exhibited the largest interdecadal amplitude. Spring showed a pattern of initial weakening followed by intensification, while autumn and winter were characterized by gradual intensification against a background of net heat sinking, with autumn displaying a transition from heat sink to heat source. EOF analysis revealed that the first mode primarily reflects long-term trends, whereas the second mode captures stronger interannual fluctuations and interdecadal adjustments, with distinct modal characteristics across seasons. M-K test results identified specific turning points in heat source variations on annual, spring, and summer scales, yet the overall abrupt change characteristics were not significant, suggesting that changes in the Qinghai-Xizang Plateau’s atmospheric heat source are primarily driven by gradual adjustments. This study elucidates the nonlinear evolution and significant seasonal variations of the atmospheric heat source over the Qinghai-Xizang Plateau, providing a reference for further understanding the plateau’s thermal anomalies and their climatic effects.