#A03 Convective gustiness and tropical precipitation biases

Poster TitleThe Role of Convective Gustiness in Reducing Seasonal Precipitation Biases in the Tropical West Pacific
AuthorsBryce Harrop Po-Lun Ma, Phil Rasch (pnl.gov) Richard NealeCecile Hannay
GroupAtmosphere
ExperimentWatercycle
Poster CategoryEarly Result
Submission Typeposter (or presentation pending simulations completing in time)
Poster LinkACME_AHMS_2017_1.pptx


Abstract

Convective gustiness reduces the precipitation bias to the north of the maritime continent in the Tropical West Pacific (TWP).  The gustiness enhances surface evaporation proportional to the amount of convective precipitation reaching the surface, which can be treated as an increase in the energy forcing into the atmosphere.  Coupled with a relatively constant normalized gross moist stability, this increase in energy forcing demands an increase in precipitation to maintain an atmosphere close to equilibrium.  The increase in tropical precipitation owing to convective gustiness is favored in regions where the large-scale circulation is weak and thus, the evaporative flux without gustiness is weak.  The increase in precipitation north of the maritime continent initiates a feedback process that results in improvements to the Southeast Asian monsoon.