Characterization of the cloud life cycle during Madden-Julian Oscillation using ARM observations

Description

The present study documented the cloud and environment properties during different phases of the Madden-Julian Oscillation (MJO) using ARM observations from the Tropical Western Pacific (TWP) Manus site and Gan Island. The long-term (13 years) KAZR (Ka-band ARM zenith radar) observations from the Manus site are used to characterize the clouds based on their height location and observed precipitation into different cloud types (boundary-layer, convective precipitating versus non-precipitating, alto, and high clouds). The differences in cloud type occurrences are analyzed for different phases of the MJO. Supplemental observations from balloon soundings, microwave radiometer (MWR), and surface rainfall are used to characterize the role of humidity on the vertical cloud distribution and precipitation-water vapor relationships. The vertical structure of large-scale environment during MJO initiation phase is analyzed using six months of sounding data collected during the ARM MJO Investigation Experiment (AMIE) field campaign at Gan Island.