Skip to content. | Skip to navigation

Personal tools

You are here: Home / Publications / Peer-reviewed papers / lmd_Picon2002_bib.html



@comment{{This file has been generated by bib2bib 1.95}}
@comment{{Command line: /usr/bin/bib2bib --quiet -c 'not journal:"Discussions"' -c 'not journal:"Polymer Science"' -c '  author:"Picon"  ' -c year=2002 -c $type="ARTICLE" -oc lmd_Picon2002.txt -ob lmd_Picon2002.bib /home/WWW/LMD/public/}}
  author = {{Roca}, R. and {Viollier}, M. and {Picon}, L. and {Desbois}, M.
  title = {{A multisatellite analysis of deep convection and its moist environment over the Indian Ocean during the winter monsoon}},
  journal = {Journal of Geophysical Research (Atmospheres)},
  keywords = {Global Change: Atmosphere (0315, 0325), Global Change: Climate dynamics (3309), Global Change: Remote sensing, Global Change: Water cycles (1836), Meteorology and Atmospheric Dynamics: Convective processes,},
  year = 2002,
  month = aug,
  volume = 107,
  eid = {8012},
  pages = {8012},
  abstract = {{The aim of this paper is to characterize the deep convective systems
over the Indian Ocean during Indian Ocean Experiment (INDOEX) and their
relationship to cloudiness and to the Upper Tropospheric Humidity (UTH)
of their environment together with the relevant longwave radiation
fields. Multisatellite analyses are performed (Meteosat, Scanner for
Radiation Budget (ScaRaB), and Special Sensor Microwave Imager (SSM/I))
to measure these environmental parameters. The use of Meteosat water
vapor (WV) channel appears very efficient not only for estimating UTH
but also for separating high level cloudiness, including thin cirrus,
from clear sky and low clouds. The Meteosat infrared (IR) and WV
channels are also used for correlating Meteosat and ScaRaB measurements,
allowing to retrieve continuously the longwave radiative flux. The
longwave flux is used to compute the cloud radiative forcing as well as
the clear-sky greenhouse effect. Spatial relationships between upper
level cloudiness and UTH are established. A strong positive linear
relationship is found suggesting a local moistening of the upper
troposphere by convection. The temporal analysis reveals that during the
active phase of the intraseasonal oscillation, the longwave cloud
radiative forcing reaches a mean value up to 40 W m$^{-2}$ over a
large region in the open ocean, while the average clear-sky greenhouse
effect is in excess of 180 W m$^{-2}$. These radiative parameters
are strongly correlated with the upper level cloudiness and upper level
moisture, respectively. The temporal variability of UTH explains up to
80\% of the greenhouse effect variability. The structure of the
convective cloud systems is then studied. The observed population of
systems spans a wide spectrum of area from 100 to 1,000,000
km$^{2}$. The contribution to the high level cloudiness of the
systems with a strong vertical development is dominant. These systems,
with at least one convective cell reaching the highest levels (below 210
K), present indices of overshooting tops and are the most horizontally
extended. The largest system exhibits an average longwave radiative
forcing of around 100 W m$^{-2}$. Their contribution to the cloud
forcing over the Indian Ocean is overwhelming. The spatial and temporal
variability of the systems is finally related to the UTH and to the
clear-sky greenhouse effect. Strong correlations are found indicating
that these organized convective systems at mesoscale play a leading role
in the Indian Ocean climate. The analysis suggests that deeper
convection is associated with larger cloud desks with larger cloud
radiative forcing. It is also associated with a moister upper
troposphere and a larger clear-sky greenhouse effect. These two effects
would provide a positive feedback on the surface conditions.
  doi = {10.1029/2000JD000040},
  adsurl = {},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
Contact information

EMC3 group

Case 99
Tour 45-55, 3ème étage
4 Place Jussieu
75252 Paris Cedex 05
Tel: 33 + 1 44 27 27 99
      33 + 6 16 27 34 18 (Dr F. Cheruy)
Tel: 33 + 1 44 27 35 25 (Secretary)
Fax: 33 + 1 44 27 62 72
email: emc3 at

Map of our location

EUREC4A campaign


Click the above logo for
the operationnal center.
Today's LMDZ meteogram