约49,000年前的末次冰盛期，北美洲的巨大冰盖通过改变全球大气环流对澳大利亚气候产生了深远影响。[1]研究人员通过气候模型实验发现，冰盖的高度而非其他因素对大气环流造成了最显著的改变。[1]该研究已发表在《Climate of the Past》期刊。[1]
研究表明，这一时期海平面下降约60米。[1]北美冰盖的白色冰面通过反射阳光起到了冷却气候的作用，但更关键的是冰盖的高度重新引导了全球风向，将热带降雨带向南移动。[1]这一变化直接增加了澳大利亚夏季季风的降雨量，同时使印尼和巴布亚新几内亚的降雨减少。[1]研究人员通过依次改变温室气体浓度、地球轨道配置、冰盖反照率和冰盖高度等参数，逐一识别了不同气候变化因素的具体影响，最终确定冰盖高度是产生最大大气环流变化的主因。[1]
A new study reveals that colossal ice sheets covering North America approximately 49,000 years ago exerted significant influence over Australia's climate through their impact on global wind patterns.[1] Researchers discovered that the height of these ice masses reshaped atmospheric circulation by redirecting the tropical rainfall belt southward, ultimately increasing summer monsoon rainfall across Australia while reducing precipitation in Indonesia and Papua New Guinea.[1]
The research, published in Climate of the Past, employed climate modeling experiments to isolate the specific mechanisms driving climate change during this period.[1] Scientists systematically modified variables including greenhouse gas concentrations, Earth's orbital configuration, ice sheet reflectivity, and ice sheet elevation to identify which factors produced the most significant atmospheric effects.[1] The ice sheet's elevation emerged as the dominant driver of atmospheric circulation changes.[1] Beyond its height, the bright white surface of the ice sheet also cooled the climate by reflecting sunlight back into space.[1] During this era, sea levels stood approximately 60 meters lower than today.[1]
