#A03 Convective gustiness and tropical precipitation biases

#A03 Convective gustiness and tropical precipitation biases

Poster Title

The Role of Convective Gustiness in Reducing Seasonal Precipitation Biases in the Tropical West Pacific

Authors

@Bryce Harrop @Po-Lun Ma, @Phil Rasch (pnl.gov) (Unlicensed) @Richard Neale (Unlicensed)@Cecile Hannay (Unlicensed)

Group

Atmosphere

Experiment

Watercycle

Poster Category

Early Result

Submission Type

poster (or presentation pending simulations completing in time)

Poster Link

ACME_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.