A detailed evaluation of the heating efficiency in the middle atmosphere
A detailed evaluation of the heating efficiency in the middle atmosphere
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DOI：
10.1029/93jd00315
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发表时间：
1993-06
影响因子：
--
通讯作者：
M. Mlynczak;S. Solomon
中科院分区：
文献类型：
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作者：
M. Mlynczak;S. Solomon
地球中层和低热层的臭氧和分子氧吸收太阳紫外线辐射，通过一系列复杂的过程将其转化为热量。在O3或O2的光解时，产生大量的化学势能和原子和分子内能。内能的配置在很大程度上决定了大气被加热的速率.此外，在放热化学反应之后释放化学能，该放热化学反应可能在光子沉积的位置之后很久并且远离光子沉积的位置发生。能量可通过激发的光解产物的气辉或放热化学反应的产物种类的荧光发射而从大气中损失。本文研究了臭氧的哈特利、哈金斯和查普伊谱带以及分子氧的赫茨伯格、Ly α、舒曼-龙格连续谱和舒曼-龙格谱带中气辉损失在降低太阳加热效率中的作用。我们还研究了加热的作用，由于七个化学反应，并计算这些反应的效率与显着的荧光损失。对于非单位效率的过程，给出了适用于数值模型的热效率参数化。对各个过程的加热率的计算结果表明，氢原子和臭氧的反应可能是中层顶附近最大的单一热源。然而，显着的改进仍然需要在知识的猝灭和化学反应速率的振动激发OH之前，这个反应的效率可以放心地计算。我们的计算还表明，即使在强猝灭下，大部分OH在85-90 km以上的振动激发形式。最后，由于太阳能和化学加热相结合的体积加热效率进行了计算。计算的体积效率表明，气辉和荧光发射显着减少整个中间层和低热层的热量可用的能量。
The conversion to heat of solar ultraviolet radiation absorbed by ozone and molecular oxygen in the terrestrial mesosphere and lower thermosphere occurs through a series of complex processes. Upon photolysis of the O3 or O2, significant amounts of chemical potential energy and atomic and molecular internal energy are generated. The disposition of the internal energy largely determines the rate at which the atmosphere is heated. In addition, the chemical energy is released subsequent to exothermic chemical reactions which may occur long after and far away from the location of photon deposition. Energy may be lost from the atmosphere by airglow from excited photolysis products or by chemiluminescent emission from product species of exothermic chemical reactions. In this paper we examine the role of airglow losses in reducing the efficiency of solar heating in the Hartley, Huggins, and Chappuis bands of ozone and in the Herzberg, Ly α, Schumann-Runge continuum, and Schumann-Runge bands of molecular oxygen. We also examine the role of heating due to seven chemical reactions and calculate the efficiencies for those reactions with significant chemiluminescent loss. Parameterizations of the heating efficiency that are readily applicable to numerical models are given for those processes with nonunit efficiencies. Results from the calculation of heating rates for individual processes indicate that the reaction of atomic hydrogen and ozone is potentially the largest single source of heat in the vicinity of the mesopause. However, significant improvement is still needed in the knowledge of the quenching and chemical reaction rates of vibrationally excited OH before the efficiency of this reaction can be confidently calculated. Our calculations also indicate that even under strong quenching, most of the OH is in vibrationally excited form above 85–90 km. Finally, the bulk heating efficiency due to the combination of solar and chemical heating is calculated. The calculated bulk efficiencies demonstrate that airglow and chemiluminescent emission significantly reduce the amount of energy available for heat throughout the mesosphere and lower thermosphere.