Response of atmospheric carbon dioxide to the secular variation of weakening geomagnetic field in whole atmosphere simulations
Response of atmospheric carbon dioxide to the secular variation of weakening geomagnetic field in whole atmosphere simulations
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DOI：
10.26464/epp2021040
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发表时间：
2021-07
影响因子：
2.9
通讯作者：
Xu Zhou;X. Yue;Han L. Liu;Yong Wei;Yongxin Pan
中科院分区：
文献类型：
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作者：
Xu Zhou;X. Yue;Han L. Liu;Yong Wei;Yongxin Pan
利用全球大气共同体气候模式扩展（WACCM-X）研究了大气CO2浓度对地磁长期变化的响应。我们的合奏模拟结果表明，CO2体积混合比（VMRs）增加在高纬度地区和减少在中，低纬度地区的几个ppmv的地磁场减弱了50%。CO2在统计上的显著变化主要出现在~90 km高度以上，并主要重新确定~100 - 110 km高度的能量收支。我们的转换欧拉平均（TEM）环流的分析发现，CO2的变化是由增强的上升流在高纬度和下降流在中，低纬度的结果增加焦耳加热。我们进一步分析了1978年至2013年期间大气CO2对实际地磁减弱的响应，并发现高纬度（中纬度和低纬度）的CO2 VMR相应增加（减少）。我们的模拟结果第一次表明，地磁变化对大气CO2分布的影响是显着的几十年的时间尺度。
Responses of atmospheric carbon dioxide (CO2) density to geomagnetic secular variation are investigated using the Whole Atmosphere Community Climate Model‐eXtended (WACCM‐X). Our ensemble simulations show that CO2 volume mixing ratios (VMRs) increase at high latitudes and decrease at mid and low latitudes by several ppmv in response to a 50% weakening of the geomagnetic field. Statistically significant changes in CO2 are mainly found above ~90 km altitude and primarily redetermine the energy budget at ~100‐110 km. Our analysis of transformed Eulerian mean (TEM) circulation found that CO2 change is caused by enhanced upwelling at high latitudes and downwelling at mid and low latitudes as a result of increased Joule heating. We further analyzed the atmospheric CO2 response to realistic geomagnetic weakening between 1978 and 2013, and found increasing (decreasing) CO2 VMRs at high latitudes (mid and low latitudes) accordingly. For the first time, our simulation results demonstrate that the impact of geomagnetic variation on atmospheric CO2 distribution is noticeable on a time scale of decades.