青藏高原气候变化的若干事实及其年际振荡的成因探讨

The truth and inter-annual oscillation causes for climate change in the Qinghai-Tibet Plateau

利用1961-2012年青藏高原88个气象台站逐月气温、降水以及温室气体等气候系统监测资料和CMIP5输出的未来气候变化情景数据,分析了近52年来青藏高原气候变化暖湿化的若干事实,揭示了其年际振荡与温室气体、高原加热场、高原季风、AO等气候系统因子的关系,预测了未来20～40年青藏高原可能的气候变化趋势。研究表明:近52年来青藏高原在总体保持气候变暖的趋势下自2006年以来出现了某些增暖趋于缓和的迹象,较全球变化滞后了8年左右;降水量的增加在青藏高原具有明显的普遍性和显著性,气候变湿较变暖具有一定的滞后性,降水量变化的5年短周期日趋不显著,而12年、25年较长周期逐渐明显且仍呈增多趋势。由于温室气体、气溶胶持续增加、高原夏季风趋强、ENSO事件和太阳辐射减少,青藏高原气候持续增暖但有所缓和;春季高原加热场增强、高原夏季风爆发提前且保持强劲,使得高原春、夏季和年降水量增加,而秋、冬季AO相对稳定少动,东亚大槽强度无明显变化,高原冬季风变化不甚显著,导致了高原秋、冬季降水量无明显变化。未来20～40年青藏高原仍有可能继续保持气温升高、降水增加趋势。

By using the monthly temperature, precipitation and greenhouse gases data from 88 meteorological stations in the Qinghai-Tibet Plateau from 1961 to 2012 as well as climate change scenarios data determined by CMIP5, several truth about warm and wet climate in the plateau for the 52 years are analyzed. The correlations among greenhouse gas, plateau heating field, plateau monsoon and the Arctic Oscillation (AO) index with its inter-annual oscillation are revealed. The possible climate change trend in the future 30-50 years is predicted. The results show that the warming trend has been alleviated since 2006 with a totally warming for 52 a;compared with global change, it has delayed for 8 a;precipitation has increased obviously in the plateau;climate wetting has delayed as compared with warming;5 a short period precipitation variation has been not significant, instead of 12 a and 25 a period precipitation variation. With the greenhouse gas and aerosol increasing, plateau summer monsoon has enhanced, ENSO events and solar radiation has decreased, climate in the plateau has become warmer continuously but eased;plateau heating field has enhanced in spring and plateau summer monsoon has erupted early and kept strong, which lead to more rainfall in spring and summer, as well as the annual precipitation;yet in autumn and winter, AO has been relatively stable, east Asian trough intensity also has changed not obviously, as well as the plateau winter monsoon, as a result, precipitation in autumn and winter also has changed insignificantly. Temperature and precipitation in the plateau will be kept increasing in the future 20-40 years.