Sensitivity of the water cycle over the Indian Ocean and Maritime Continent to parameterized physics in a regional model

Marcela Ulate, Jimy Dudhia, Chidong Zhang

Research output: Contribution to journalArticle

8 Scopus citations

Abstract

A regional model was used to simulate the water cycle over the Indian Ocean (IO) and Maritime Continent (MC). Sixteen 92 day simulations were performed using different combinations of eight cumulus parameterization schemes and three planetary boundary-layer (PBL) parameterization schemes. The strength of the water cycle in the IO and MC, measured by its domain mean precipitation and precipitable water, differs substantially among the simulations. The large spread of water cycle strength is mainly toward dry biases in comparison to global data assimilation products. The simulated water cycle, its spread, and biases differ between the IO and MC. Influences of PBL schemes can penetrate into the upper troposphere and those by cumulus schemes into the boundary layer. Dry biases in the simulations are produced mainly because of feedbacks among erroneously low diabatic heating peaks, shallow moisture convergence layers, dry lower troposphere, and weak surface evaporation. There is no single type of parameterization scheme that can be identified to be the main sources of the dry biases. It is the combination of errors from three types of parameterization schemes, namely, cumulus, PBL, and microphysics, that makes the simulated water cycle unrealistic. The lesson learned is that the tropical water cycle can be better simulated only by improving parameterization schemes of different processes all together as a package. Key Points: The water cycle can be better simulated only by improving model physics Biases produced by a PBL scheme can penetrate into the middle troposphere Biases produced by cumulus schemes can penetrate into the boundary layer

Original languageEnglish (US)
Pages (from-to)1095-1120
Number of pages26
JournalJournal of Advances in Modeling Earth Systems
Volume6
Issue number4
DOIs
StatePublished - Dec 1 2014

Keywords

  • regional modeling
  • sensitivity cumulus scheme
  • sensitivity planetary boundary layer
  • water budget
  • water cycle Indian Ocean Maritime Continent
  • WRF

ASJC Scopus subject areas

  • Global and Planetary Change
  • Environmental Chemistry
  • Earth and Planetary Sciences(all)

Fingerprint Dive into the research topics of 'Sensitivity of the water cycle over the Indian Ocean and Maritime Continent to parameterized physics in a regional model'. Together they form a unique fingerprint.

  • Cite this