Climate networks suggest Rossby-waves-related CO₂concentrations to surface air temperature

The role of carbon dioxide (CO2) on global warming gained wide attention. Previous researches mainly focus on relationship between global average CO2 concentrations and surface air temperature (SAT). Carbon satellites have proven that CO2 concentrations have non-uniform spatio-temporal distributions. The relation between CO2 concentrations from satellite observations and SAT is seldom reported. Climate network approaches have been successful to uncover topology structure and dynamics in the climate system. Here, we construct CO2 concentrations network and SAT network based on the climate network approaches. By comparing the similarity of the properties between CO2 concentrations network and SAT network, their relation has been investigated. We show that negative and positive links in CO2 network have a strong correlation with that in the SAT network. These statistical structures yield a clear association with the pattern of Rossby waves. It is shown that the peaks of phase speeds associated with significant positive and negative weight links are similar, and are arranged in the group velocities of Rossby waves. Further analysis shows their strong correlations and similarity spatial patterns if the equator regions are excluded. In addition, their teleconnections follow similar climate processes, where Rossby waves exhibit dominance in the Southern Hemisphere. The results demonstrate the similar network properties between CO2 and SAT can be partly related to the function of Rossby waves. Our work provides a new perspective with which to understand the relation between CO2 concentrations and SAT, as well as climate system.