Maintenance mechanisms for the early-morning maximum summer rainfall over southeast China

Wan-Ru Huang, Johnny C.L. Chan

Research output: Contribution to journalArticle

24 Citations (Scopus)

Abstract

During the summer months, diurnal rainfall variation over southeast China is frequently characterized by a major peak in the afternoon and a minor peak in the early morning. While the afternoon rainfall maximum is generally recognized to be mainly modulated by the diurnally varying wind introduced by land-sea and mountain-valley differential heating, causes of the early-morning rainfall are not well documented. In this study, variation in the semi-diurnal harmonic of rainfall is found to be more important than variation in the diurnal harmonic of rainfall for determining the timing of the early-morning rainfall peak. Diagnoses of the atmospheric thermodynamic conditions indicate that late-night vertical differential thermal advection and semi-diurnal variation in land-sea differential radiative heating/cooling are the major reasons for reduction in stability in the early morning and, in turn, facilitate the formation of an early-morning maximum in rainfall. Computation of the water vapor budget suggests further that the early-morning maximum over southeast China is mainly maintained by the semi-diurnal harmonic of water vapor flux transported from the South China Sea.

Original languageEnglish
Pages (from-to)959-968
Number of pages10
JournalQuarterly Journal of the Royal Meteorological Society
Volume137
Issue number657
DOIs
Publication statusPublished - 2011 Jan 1

Fingerprint

rainfall
summer
water vapor
heating
diurnal variation
advection
thermodynamics
cooling
valley
mountain
land
sea

Keywords

  • Atmospheric heat budget
  • Semi-diurnal variation
  • Water vapor budget

ASJC Scopus subject areas

  • Atmospheric Science

Cite this

Maintenance mechanisms for the early-morning maximum summer rainfall over southeast China. / Huang, Wan-Ru; Chan, Johnny C.L.

In: Quarterly Journal of the Royal Meteorological Society, Vol. 137, No. 657, 01.01.2011, p. 959-968.

Research output: Contribution to journalArticle

@article{9abef2aa3be3404b8e27562a3d1332b7,
title = "Maintenance mechanisms for the early-morning maximum summer rainfall over southeast China",
abstract = "During the summer months, diurnal rainfall variation over southeast China is frequently characterized by a major peak in the afternoon and a minor peak in the early morning. While the afternoon rainfall maximum is generally recognized to be mainly modulated by the diurnally varying wind introduced by land-sea and mountain-valley differential heating, causes of the early-morning rainfall are not well documented. In this study, variation in the semi-diurnal harmonic of rainfall is found to be more important than variation in the diurnal harmonic of rainfall for determining the timing of the early-morning rainfall peak. Diagnoses of the atmospheric thermodynamic conditions indicate that late-night vertical differential thermal advection and semi-diurnal variation in land-sea differential radiative heating/cooling are the major reasons for reduction in stability in the early morning and, in turn, facilitate the formation of an early-morning maximum in rainfall. Computation of the water vapor budget suggests further that the early-morning maximum over southeast China is mainly maintained by the semi-diurnal harmonic of water vapor flux transported from the South China Sea.",
keywords = "Atmospheric heat budget, Semi-diurnal variation, Water vapor budget",
author = "Wan-Ru Huang and Chan, {Johnny C.L.}",
year = "2011",
month = "1",
day = "1",
doi = "10.1002/qj.815",
language = "English",
volume = "137",
pages = "959--968",
journal = "Quarterly Journal of the Royal Meteorological Society",
issn = "0035-9009",
publisher = "John Wiley and Sons Ltd",
number = "657",

}

TY - JOUR

T1 - Maintenance mechanisms for the early-morning maximum summer rainfall over southeast China

AU - Huang, Wan-Ru

AU - Chan, Johnny C.L.

PY - 2011/1/1

Y1 - 2011/1/1

N2 - During the summer months, diurnal rainfall variation over southeast China is frequently characterized by a major peak in the afternoon and a minor peak in the early morning. While the afternoon rainfall maximum is generally recognized to be mainly modulated by the diurnally varying wind introduced by land-sea and mountain-valley differential heating, causes of the early-morning rainfall are not well documented. In this study, variation in the semi-diurnal harmonic of rainfall is found to be more important than variation in the diurnal harmonic of rainfall for determining the timing of the early-morning rainfall peak. Diagnoses of the atmospheric thermodynamic conditions indicate that late-night vertical differential thermal advection and semi-diurnal variation in land-sea differential radiative heating/cooling are the major reasons for reduction in stability in the early morning and, in turn, facilitate the formation of an early-morning maximum in rainfall. Computation of the water vapor budget suggests further that the early-morning maximum over southeast China is mainly maintained by the semi-diurnal harmonic of water vapor flux transported from the South China Sea.

AB - During the summer months, diurnal rainfall variation over southeast China is frequently characterized by a major peak in the afternoon and a minor peak in the early morning. While the afternoon rainfall maximum is generally recognized to be mainly modulated by the diurnally varying wind introduced by land-sea and mountain-valley differential heating, causes of the early-morning rainfall are not well documented. In this study, variation in the semi-diurnal harmonic of rainfall is found to be more important than variation in the diurnal harmonic of rainfall for determining the timing of the early-morning rainfall peak. Diagnoses of the atmospheric thermodynamic conditions indicate that late-night vertical differential thermal advection and semi-diurnal variation in land-sea differential radiative heating/cooling are the major reasons for reduction in stability in the early morning and, in turn, facilitate the formation of an early-morning maximum in rainfall. Computation of the water vapor budget suggests further that the early-morning maximum over southeast China is mainly maintained by the semi-diurnal harmonic of water vapor flux transported from the South China Sea.

KW - Atmospheric heat budget

KW - Semi-diurnal variation

KW - Water vapor budget

UR - http://www.scopus.com/inward/record.url?scp=79957915761&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79957915761&partnerID=8YFLogxK

U2 - 10.1002/qj.815

DO - 10.1002/qj.815

M3 - Article

AN - SCOPUS:79957915761

VL - 137

SP - 959

EP - 968

JO - Quarterly Journal of the Royal Meteorological Society

JF - Quarterly Journal of the Royal Meteorological Society

SN - 0035-9009

IS - 657

ER -