摘要
Responses of atmospheric carbon dioxide(CO_(2))density to geomagnetic secular variation are investigated using the Whole Atmosphere Community Climate Model-eXtended(WACCM-X).Our ensemble simulations show that CO_(2) 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 CO_(2) 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 CO_(2) 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 CO_(2) response to realistic geomagnetic weakening between 1978 and 2013,and found increasing(decreasing)CO_(2) 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 CO_(2) distribution is noticeable on a time scale of decades.
基金
This work was supported by the B-type Strategic Priority Program of the Chinese Academy of Sciences(Grant No.XDB41000000)
the National Natural Science Foundation of China(41621004,41427901)
the Open Research Project of Large Research Infrastructures—“Study on the interaction between low/mid-latitude atmosphere and ionosphere based on the Chinese Meridian Project”
the Key Research Program of the IGGCAS with Grant No.IGGCAS-201904
XZ thanks the UCAS Joint PhD Training Program.The National Center for Atmospheric Research is a major facility sponsored by the National Science Foundation under Cooperative Agreement No.1852977.
