Convective Precipitation Efficiency Observed in the Tropics

Sugata Narsey, Christian Jakob, Martin S. Singh, Martin Bergemann, Valentin Louf, Alain Protat, Christopher Williams

Research output: Contribution to journalArticleResearchpeer-review

22 Citations (Scopus)

Abstract

Precipitation efficiency refers to the fraction of condensate in the atmosphere that reaches the surface as precipitation. A high-quality data set of radar-estimated precipitation rates and convective scale vertical velocity near Darwin, Australia, is used to construct the first estimate of precipitation efficiency at convective scales for a long record of observations in the tropics. It is found that precipitation efficiency increases with precipitation rate and midtropospheric humidity and decreases with increasing convective available potential energy and surface temperature. Precipitation efficiency is largest under moist monsoonal conditions and smallest during monsoon break periods, which are characterized by a drier free troposphere. However, these differences in efficiency do not translate to differences in the instantaneous precipitation rate across the synoptic regimes because of a compensating change in the net condensation rate. This is driven by variations in cloud updraft velocity, which is larger in drier environments than in moist environments.

Original languageEnglish
Pages (from-to)13574–13583
Number of pages10
JournalGeophysical Research Letters
Volume46
Issue number22
DOIs
Publication statusPublished - 28 Nov 2019

Keywords

  • convection
  • extremes
  • observations
  • precipitation efficiency
  • rainfall
  • tropics

Cite this