The energetics response to a warmer climate: relative contributions from the transient and stationary eddies
The energetics response to a warmer climate: relative contributions from the transient and stationary eddies
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DOI：
10.5194/esd-2-105-2011
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发表时间：
2011-01-01
影响因子：
7.3
通讯作者：
von Storch, J. -S.
中科院分区：
文献类型：
--
作者：
Hernandez-Deckers, D.;von Storch, J. -S.
我们使用洛伦兹能量循环（LEC），以评估全球能源活动的变化，由于CO2倍增的耦合大气-海洋ECHAM 5/MPI-OM模式。全球范围内，能量活动-以可用势能转化为动能的总转化率衡量-减少了约4%。这种减弱是由对流层上层LEC的加强和对流层中下层LEC的减弱的双重响应引起的。这是完全一致的结果，从一个较粗的分辨率版本相同的耦合模式。我们进一步利用实验研究了瞬态和稳态涡旋分量对主要能量响应的贡献，瞬态涡旋项对总能量活动的贡献大于稳态涡旋项。我们发现，这也是正确的，在他们的2 × CO2响应。瞬态涡流分量的变化决定了主要的能量响应，而稳态涡流分量的贡献很小。因此，在对流层上部的双重响应加强和下面的减弱主要涉及瞬态涡项。我们可以定性地将这种反应与2 × CO2变暖模式的两个主要特征联系起来：（a）热带对流层上层变暖增加了两极到赤道的温度梯度-加强了上层的能量活动-并增强了静态稳定性-削弱了下层的能量活动;（B）高纬度地面变暖降低了对流层低层的极赤道温度梯度，减弱了低层的能量活动。尽管静止涡旋对主要能量响应的贡献很小，但静止涡旋有效位能（P-se）的变化反映了暖化格局的某些特征：副热带地区较强的海陆对比和北方高纬度地区较弱的海陆对比影响P-se的区域性，但不影响全球能量响应。
We use the Lorenz Energy Cycle (LEC) to evaluate changes in global energetic activity due to CO2-doubling in the coupled atmosphere-ocean ECHAM5/MPI-OM model. Globally, the energetic activity - measured as the total conversion rate of available potential energy into kinetic energy - decreases by about 4%. This weakening results from a dual response that consists of a strengthening of the LEC in the upper-troposphere and a weakening in the lower and middle troposphere. This is fully consistent with results from a coarser resolution version of the same coupled model. We further use our experiments to investigate the individual contributions of the transient and stationary eddy components to the main energetics response.The transient eddy terms have a larger contribution to the total energetic activity than the stationary ones. We find that this is also true in terms of their 2 x CO2-response. Changes in the transient eddy components determine the main energetics response, whereas the stationary eddy components have very small contributions. Hence, the dual response strengthening in the upper troposphere and weakening below - concerns mainly the transient eddy terms. We can relate qualitatively this response to the two main features of the 2 x CO2 warming pattern: (a) the tropical upper-tropospheric warming increases the pole-to-equator temperature gradient - strengthening the energetic activity above - and enhances static stability - weakening the energetic activity below; and (b) the high-latitude surface warming decreases the pole-to-equator temperature gradient in the lower troposphere - weakening the energetic activity below. Despite the small contribution from the stationary eddies to the main energetics response, changes in stationary eddy available potential energy (P-se) reflect some features of the warming pattern: stronger land-sea contrasts at the subtropics and weaker land-sea contrasts at the high northern latitudes affect P-se regionally, but do not affect the global energetics response.