Anthropogenic Aerosols, Greenhouse Gases, and the Uptake, transport, and Storage of Excess Heat in the Climate System
Anthropogenic Aerosols, Greenhouse Gases, and the Uptake, transport, and Storage of Excess Heat in the Climate System
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DOI：
10.1029/2019gl082015
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发表时间：
2019-05-16
影响因子：
5.2
通讯作者：
Church, J. A.
中科院分区：
文献类型：
--
作者：
Irving, D. B.;Wijffels, S.;Church, J. A.
造成地球能源不平衡的最大因素是混合良好的温室气体（GHG），而混合不良（因此北中纬度地区占主导地位）的人为气溶胶（AA）部分抵消了温室气体的影响。为了分离GHG和AA的影响，我们分析了CMIP5历史（即所有自然和人为强迫）和单一强迫（仅GHG和仅AA）实验的数据。在历史实验期间（1861-2005），大气层顶部和海洋表面的过量热量吸收几乎全部发生在南半球，而AA抵消了北半球温室气体的影响。这种表面吸热的半球不对称性被向北海洋输送多余热量所消除，因为在考虑海洋体积后，历史海洋储热几乎没有半球差异。 1pctCO2 和 RCP 8.5 实验的数据表明，未来多余热量的储存将偏向北半球海洋。 通俗易懂的总结 气候变化从根本上来说是一个能量平衡问题。由于温室气体（GHG）排放的影响，目前地球吸收的太阳能量大于辐射到太空的能量量。这种能量不平衡被燃烧化石燃料（人为气溶胶，AA）释放到大气中的颗粒物部分抵消，这些颗粒物最集中在北部中纬度地区。在这项研究中，对历史和未来气候的模型模拟与仅应用温室气体或AA排放的单一强迫模拟进行了比较。我们发现，历史上多余热量的吸收严重偏向南半球，因为AA抵消了北半球温室气体的影响。由于多余热量强烈向北输送，海洋储存的热量在半球之间几乎没有差异。模型表明，未来多余的热量储存将偏向北半球。
The largest contributor to the planetary energy imbalance is well-mixed greenhouse gases (GHGs), which are partially offset by poorly mixed (and thus northern midlatitude dominated) anthropogenic aerosols (AAs). To isolate the effects of GHGs and AAs, we analyze data from the CMIP5 historical (i.e., all natural and anthropogenic forcing) and single forcing (GHG-only and AA-only) experiments. Over the duration of the historical experiment (1861-2005) excess heat uptake at the top of the atmosphere and ocean surface occurs almost exclusively in the Southern Hemisphere, with AAs canceling the influence of GHGs in the Northern Hemisphere. This interhemispheric asymmetry in surface heat uptake is eliminated by a northward oceanic transport of excess heat, as there is little hemispheric difference in historical ocean heat storage after accounting for ocean volume. Data from the 1pctCO2 and RCP 8.5 experiments suggests that the future storage of excess heat will be skewed toward the Northern Hemisphere oceans.Plain Language Summary Climate change is fundamentally an energy balance problem. Due to the influence of greenhouse gas (GHG) emissions, the amount of solar energy absorbed by Earth is currently greater than the amount of energy radiated to space. This energy imbalance is partially offset by particulate matter released into the atmosphere from burning fossil fuels (anthropogenic aerosols, AAs), which is most concentrated in the northern midlatitudes. In this study, model simulations of the historical and future climate are compared to single forcing simulations that apply only GHG or AA emissions. We find that the historical uptake of excess heat is strongly skewed toward the Southern Hemisphere because AAs cancel the influence of GHGs in the Northern Hemisphere. The oceanic storage of that heat shows little difference between the hemispheres due to a strong northward transport of excess heat. In future, the models suggest excess heat storage will skew toward the Northern Hemisphere.