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最近的第四纪大冰期的特点是全球气候经历了冰期和间冰期的多次相互转换。Louvain-La-Neuve的二维(高度-纬度)气候模型(LLN二维模型)已经被应用于模拟北半球气候的长期变化。这个模型每天和每个纬度都受到二氧化碳和太阳辐射强迫。这里分析的时期是从距今20万年以前到今后20万年。这个模型给出了整个大陆的冰含量,与SPECMAP 氧同位素记录比较吻合,各个北半球大冰原的大小和范围与它们的地质重构相当一致。已经做了7个模拟实验来量化太阳辐射和CO_2强迫以及反照率和水汽温度反馈对于末次盛冰期(LGM)时变冷的贡献。这个4.5℃的末次盛冰期降温20.8%是由于CO_2的影响,太阳辐射和反照率温度反馈的影响占40%,水汽的反馈占38.6%。如果我们将低CO_2浓度作为唯一的强迫,但让水汽变化,那么可以解释降温的33%。
The most recent Quaternary Great Ice Age was characterized by a number of interconversion of the global climate over the glacial and interglacial periods. The two-dimensional (latitude-longitude) climate model (LLN two-dimensional model) of Louvain-La-Neuve has been applied to simulate the long-term climate change in the northern hemisphere. This model is forced by carbon dioxide and solar radiation every day and every latitude. The period of analysis here is from 200,000 years ago to 200,000 years to come. This model gives an overview of the ice content across the continent, consistent with the SPECMAP Oxygen Isotope record, and the size and extent of the various northern hemispheric ice packs are quite consistent with their geological reconstructions. Seven simulations have been done to quantify solar radiation and CO 2 coercion and the contribution of albedo and vapor temperature feedback to cooling in the last ice age (LGM). The temperature drop of 20.8% in the last glaciation of 4.5 ℃ is due to the influence of CO_2. The influence of solar radiation and albedo temperature feedback is 40% and that of water vapor is 38.6%. If we use low CO 2 concentration as the only coercion, but let the water vapor change, we can account for 33% of the cooling down.