Representations of Precipitation Diurnal Cycle in the Amazon as Simulated by Observationally Constrained Cloud-System Resolving and Global Climate Models Academic Article uri icon


  • AbstractThe ability of an observationallyconstrained cloudsystem resolving model (Weather Research and Forecasting; WRF, 4km grid spacing) and a global climate model (Energy Exascale Earth System Model; E3SM, 1degree grid spacing) to represent the precipitation diurnal cycle over the Amazon basin during the 2014 wet season is assessed. The WRF model coupled with a 3D variational data assimilation scheme reproduces the spatial variability of the precipitation diurnal cycle over the basin and the lifecycle of westward propagating MCSs initiated by the coastal seabreeze front. In contrast, a single morning peak in rainfall is produced by E3SM for simulations despite the nudging of largescale winds toward global reanalysis, indicating precipitation in E3SM is largely controlled by local convection associated with diurnal heating. The role of propagating MCS on the environment are discussed by using a multivariate perturbation analysis. We also find that the advection of moisture perturbations from ocean to inland regions have a higher correlation with the occurrence of MCSs in the Amazon than the intensity of colder air intrusion associated with sea breezes along the coast. Moreover, the presence of large cold pools over the central Amazon basin are responsible for the maintenance of propagating deep convection.

published proceedings


altmetric score

  • 1

author list (cited authors)

  • Tai, S., Feng, Z., Ma, P., Schumacher, C., & Fast, J. D.

citation count

  • 9

complete list of authors

  • Tai, Sheng-Lun||Feng, Zhe||Ma, Po-Lun||Schumacher, Courtney||Fast, Jerome D

publication date

  • November 2021