Measuring and modeling the lifetime of nitrous oxide including its variability.
Measuring and modeling the lifetime of nitrous oxide including its variability.
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DOI：
10.1002/2015jd023267
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发表时间：
2015-06-16
期刊：
影响因子：
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通讯作者：
Funke B
中科院分区：
文献类型：
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作者：
Prather MJ;Hsu J;DeLuca NM;Jackman CH;Oman LD;Douglass AR;Fleming EL;Strahan SE;Steenrod SD;Søvde OA;Isaksen IS;Froidevaux L;Funke B
一氧化二氮是人类排放的第三大温室气体，到目前为止，一氧化二氮的寿命主要基于模型研究或按比例计算其他气体。这项工作基于微波肢体探测仪卫星测量的一氧化二氮、臭氧和温度的平流层轮廓、O(1D)的臭氧和分子氧加上动力学的实验室截面数据、观测的太阳光谱和一个简单的辐射传输模型来计算半经验寿命。结果为116 ± 9 年。观测到的寿命和热带丰度的月际变化与观测期间(2005年至2010年)由再分析气象场驱动的4个独立的化学输送模型很好地匹配，但所有这些模型都高估了寿命，因为在热带32 公里附近的临界损失区丰度较低。这些模型加上一个化学-气候模型，一致认为一氧化二氮的反馈因子本身的寿命为0.94 ± 0.01，给出了N2O扰动的有效停留时间为109 年。将这一新的经验寿命与停留时间和工业化前寿命(123年 年)的模型估计相结合，调整了我们对当今人类-自然排放平衡的最佳估计，并提高了本世纪一氧化二氮预测增长的准确性。一氧化二氮寿命是根据MLS卫星数据经验计算的，与包括年际变化结果的模型相比，经验N2O寿命改善了目前人为和工业化前排放的值
The lifetime of nitrous oxide, the third‐most‐important human‐emitted greenhouse gas, is based to date primarily on model studies or scaling to other gases. This work calculates a semiempirical lifetime based on Microwave Limb Sounder satellite measurements of stratospheric profiles of nitrous oxide, ozone, and temperature; laboratory cross‐section data for ozone and molecular oxygen plus kinetics for O(1D); the observed solar spectrum; and a simple radiative transfer model. The result is 116 ± 9 years. The observed monthly‐to‐biennial variations in lifetime and tropical abundance are well matched by four independent chemistry‐transport models driven by reanalysis meteorological fields for the period of observation (2005–2010), but all these models overestimate the lifetime due to lower abundances in the critical loss region near 32 km in the tropics. These models plus a chemistry‐climate model agree on the nitrous oxide feedback factor on its own lifetime of 0.94 ± 0.01, giving N2O perturbations an effective residence time of 109 years. Combining this new empirical lifetime with model estimates of residence time and preindustrial lifetime (123 years) adjusts our best estimates of the human‐natural balance of emissions today and improves the accuracy of projected nitrous oxide increases over this century. Nitrous oxide lifetime is computed empirically from MLS satellite data Empirical N2O lifetimes compared with models including interannual variability Results improve values for present anthropogenic and preindustrial emissions