Quantifying the strength of land-atmosphere coupling in the 2004 North American monsoon

This study examines the land-atmosphere coupling strength during the 2004 North American monsoon (NAM) using the index from ensemble model simulations. The strength of coupling varies geographically over different monsoon phases. The coupling strength over the entire monsoon period is primarily attributed to the monsoon mature phase with strong signal of coupling in the eastern NAM region. A decomposition of the land-atmosphere coupling suggests that land segment contributes to the strong coupling during the monsoon onset, mature phase and the overall monsoon season, while the atmospheric segment dominates the strong coupling during the decay phase.