Convective initiation sensitivity to the presence of an oceanic barrier layer

Friday, 19 December 2014: 8:15 AM
Sue Chen1, Jerome Schmidt1, Maria K. Flatau2, James G Richman3 and Tommy G Jensen4, (1)Naval Research Lab Monterey, Monterey, CA, United States, (2)Naval Research Laboratory, Monterey, CA, United States, (3)Naval Research Lab Stennis Space Center, Stennis Space Center, MS, United States, (4)Naval Research Laboratory, Stennis Space Center, MS, United States
Observations from the CINDY/DYNAMO field campaign reveal the formation of an oceanic barrier layer after the passage of Madden Julian Oscillation (MJO) events. The motivation for the work stems from the CINDY/DYNAMO hypothesis III which states: “The barrier-layer, wind- and shear-driven mixing, shallow thermocline, and mixing-layer entrainment all play essential roles in the MJO initiation over the Indian Ocean by controlling the upper-ocean heat content and sea surface temperature, and thereby surface flux feedback”. An idealized Coupled Ocean/Atmospheric Mesoscale Prediction System (COAMPS) framework is used to study the sensitivity of the barrier layer influence on the transition of post MJO dry phase to the pre-MJO moist phase. We will discuss results from the idealized coupled simulations that are initialized either with or without the barrier layer. The sensitivity of the atmospheric boundary moisture recovery due to the presence of barrier layer as well as the sensitivity to the convective initiation will be presented.