Inverse modeling of global and regional CH4 emissions using SCIAMACHY satellite retrievals
Inverse modeling of global and regional CH4 emissions using SCIAMACHY satellite retrievals
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DOI：
10.1029/2009jd012287
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发表时间：
2009-11-17
影响因子：
4.4
通讯作者：
Levin, Ingeborg
中科院分区：
文献类型：
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作者：
Bergamaschi, Peter;Frankenberg, Christian;Levin, Ingeborg
ENVISAT 上的大气制图扫描成像吸收光谱仪 (SCIAMACHY) 仪器的甲烷反演提供了有关大气 CH4 来源的重要信息，特别是在现场表面观测监测效果不佳的热带地区。最近，弗兰肯伯格等人。 (2008a, 2008b) 报告了由于水蒸气和 CH4 光谱参数的更新，SCIAMACHY 检索结果进行了重大修订。在这里，我们使用 TM5-4DVAR 逆向建模系统分析了此次修订对 2004 年全球和区域 CH4 排放估算的影响。基于修订版 SCIAMACHY 反演的反演结果显示，与之前的反演相比，热带排放量降低了 20%。新的检索显着提高了观察到的和同化的柱平均混合比之间的一致性以及与独立验证数据的一致性。此外，以前 SCIAMACHY 检索的相当大的纬度和季节偏差校正（通过同时同化高精度表面测量在 TM5-4DVAR 系统中得出）减少了大约 3 倍。与自下而上的清单相比，反演导致排放的空间模式及其季节性发生显着变化。进行了灵敏度测试来分析检索的排放的稳健性，揭示了对所应用的先验排放清单和 OH 字段的一些依赖性。此外，我们使用 NOAA 船舶和飞机剖面样本以及平流层气球样本对模拟 CH4 混合比进行了详细验证，显示出总体良好的一致性。我们利用 TM5 模型的缩放功能，使用新的 SCIAMACHY 检索对南美洲、非洲和亚洲的 CH4 排放量进行区域分析。这样可以对空间排放模式进行更详细的分析，并与飞机概况和南美洲可用的独立区域排放估算进行更好的比较。大量 CH4 排放归因于热带南美洲和非洲的各个湿地地区，这些湿地区域随季节变化，且与生物质燃烧产生的 CH4 排放反相。印度、中国和东南亚的特点是稻田排放量在今年第三季度达到峰值，此外全年人为排放量也不断增加。
Methane retrievals from the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) instrument onboard ENVISAT provide important information on atmospheric CH4 sources, particularly in tropical regions which are poorly monitored by in situ surface observations. Recently, Frankenberg et al. (2008a, 2008b) reported a major revision of SCIAMACHY retrievals due to an update of spectroscopic parameters of water vapor and CH4. Here, we analyze the impact of this revision on global and regional CH4 emissions estimates in 2004, using the TM5-4DVAR inverse modeling system. Inversions based on the revised SCIAMACHY retrievals yield similar to 20% lower tropical emissions compared to the previous retrievals. The new retrievals improve significantly the consistency between observed and assimilated column average mixing ratios and the agreement with independent validation data. Furthermore, the considerable latitudinal and seasonal bias correction of the previous SCIAMACHY retrievals, derived in the TM5-4DVAR system by simultaneously assimilating high-accuracy surface measurements, is reduced by a factor of similar to 3. The inversions result in significant changes in the spatial patterns of emissions and their seasonality compared to the bottom-up inventories. Sensitivity tests were done to analyze the robustness of retrieved emissions, revealing some dependence on the applied a priori emission inventories and OH fields. Furthermore, we performed a detailed validation of simulated CH4 mixing ratios using NOAA ship and aircraft profile samples, as well as stratospheric balloon samples, showing overall good agreement. We use the new SCIAMACHY retrievals for a regional analysis of CH4 emissions from South America, Africa, and Asia, exploiting the zooming capability of the TM5 model. This allows a more detailed analysis of spatial emission patterns and better comparison with aircraft profiles and independent regional emission estimates available for South America. Large CH4 emissions are attributed to various wetland regions in tropical South America and Africa, seasonally varying and opposite in phase with CH4 emissions from biomass burning. India, China and South East Asia are characterized by pronounced emissions from rice paddies peaking in the third quarter of the year, in addition to further anthropogenic emissions throughout the year.