Scale-interactions among Atmospheric Rivers, Mid-latitude Cyclones, and Planetary Waves

An atmospheric river (AR) is a narrow corridor or filament of concentrated moisture flux in the atmosphere, and a single one can carry a greater flux of water than the Earth's largest river, the Amazon River. ARs deliver much of the water vapor from the tropical and subtropical oceans to mid-latitudes, and have a central role in the global water cycle. On any given day, atmospheric rivers account for over 90% of the global meridional water vapor transport. This study analyzes the scale-interactions among ARs, mid-latitude cyclones, and planetary waves using 36 years (1979-2015) of ERA-Interim reanalysis data. ARs and mid-latitude cyclones are identified by automatic tracking schemes, while planetary waves are identified by space-time spectral analysis. All AR events are composited with respect to the associated mid-latitude cyclones, and against the different phases of the planetary waves. We found interesting interactions among the three phenomena at different temporal and spatial scales. Detailed results will be presented at the conference.