Influence of precipitating systems on upper Indian Ocean stability during DYNAMO

Friday, 19 December 2014
Elizabeth Jennifer Thompson1, Steven A Rutledge1, James N Moum2 and Chris W Fairall3, (1)Colorado State University, Fort Collins, CO, United States, (2)Oregon State Univ, Corvallis, OR, United States, (3)NOAA Boulder, Boulder, CO, United States
The 2011-2012 Dynamics of the Madden-Julian Oscillation (DYNAMO) field campaign produced collocated radar, lidar, ocean, and surface flux datasets at the Revelle research ship to study air-sea interactions related to MJO initiation in the central Indian Ocean. These data have been used to identify precipitation and atmospheric cold pool events at the ship, which appear to contribute different amounts of heat momentum, and salinity into the upper ocean. This study examines how the sequence of radar-indicated convective and stratiform precipitation elements, including their wind stress, gustiness, and rain, affect the erosion or buildup of upper ocean stability. Vertical gradients of potential density, potential temperature, and salinity as well as the resulting mixed layer depth and buoyancy flux quantify how precipitation influences the upper ocean throughout each precipitation and atmospheric cold pool event, the diurnal cycle, and two MJOs observed during DYNAMO.