Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

IF value: 5.414
IF5.414
IF 5-year value: 5.958
IF 5-year
5.958
CiteScore value: 9.7
CiteScore
9.7
SNIP value: 1.517
SNIP1.517
IPP value: 5.61
IPP5.61
SJR value: 2.601
SJR2.601
Scimago H <br class='widget-line-break'>index value: 191
Scimago H
index
191
h5-index value: 89
h5-index89
Volume 11, issue 8
Atmos. Chem. Phys., 11, 3811–3821, 2011
https://doi.org/10.5194/acp-11-3811-2011
© Author(s) 2011. This work is distributed under
the Creative Commons Attribution 3.0 License.
Atmos. Chem. Phys., 11, 3811–3821, 2011
https://doi.org/10.5194/acp-11-3811-2011
© Author(s) 2011. This work is distributed under
the Creative Commons Attribution 3.0 License.

  27 Apr 2011

27 Apr 2011

The role of tropical deep convective clouds on temperature, water vapor, and dehydration in the tropical tropopause layer (TTL)

J. H. Chae1,2, D. L. Wu1, W. G. Read1, and S. C. Sherwood3 J. H. Chae et al.
  • 1Jet propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
  • 2Joint Institute for Regional Earth System Science and Engineering University of California, Los Angeles, California, USA
  • 3Climate Change Research Centre, University of New South Wales, Sydney, Australia

Abstract. Temperature and water vapor variations due to clouds in the tropical tropopause layer (TTL) are investigated using co-located MLS, CALIPSO, and CloudSat data. Convective cooling occurs only up to the cloud tops, with warming above these heights in the TTL. Water vapor and ozone anomalies above the cloud tops are consistent with the warming being due to downward motion. Thicker clouds are associated with larger anomalies. Environmental water vapor below cloud tops can be either higher or lower than when clouds are absent, depending on the cloud top height. The critical factor determining the sign of this change appears to be the relative humidity. In general cloud-forming processes hydrate the environment below 16 km, where the air after mixing between cloud and the environmental air does not reach saturation, but clouds dehydrate above 16 km, as the larger temperature drop and the high initial relative humidity cause supersaturation to occur. Negative water vapor anomalies above cloud tops compared to clear skies suggest another dehydration mechanism operating above the detected cloud layers.

Publications Copernicus
Download
Citation
Final-revised paper
Preprint