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

Journal metrics

Journal metrics

  • IF value: 5.509 IF 5.509
  • IF 5-year value: 5.689 IF 5-year 5.689
  • CiteScore value: 5.44 CiteScore 5.44
  • SNIP value: 1.519 SNIP 1.519
  • SJR value: 3.032 SJR 3.032
  • IPP value: 5.37 IPP 5.37
  • h5-index value: 86 h5-index 86
  • Scimago H index value: 161 Scimago H index 161
Discussion papers
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Research article 20 Nov 2018

Research article | 20 Nov 2018

Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Atmospheric Chemistry and Physics (ACP).

Convective hydration in the tropical tropopause layer during the StratoClim aircraft campaign: Pathway of an observed hydration patch

Keun-Ok Lee1, Thibaut Dauhut1, Jean-Pierre Chaboureau1, Sergey Khaykin2, Martina Krämer3, and Christian Rolf3 Keun-Ok Lee et al.
  • 1Laboratoire d'Aérologie, Université de Toulouse, CNRS, UPS, Toulouse, France
  • 2LATMOS-IPSL, Universié Versailles St-Quentin, Sorbonne Université, CNRS/INSU, Guyancourt, France
  • 3Institute for Energy and Climate Research – Stratosphere (IEK-7), Forschungzentrum Jülich , Jülich, Germany

Abstract. The source and pathway of the hydration patch in the TTL (Tropical Tropopause Layer) that was measured during the StratoClim field campaign during the Asian summer monsoon in 2017, and its connection to convective overshoots are investigated. During flight #7, two remarkable layers are measured in the TTL namely, (1) moist layer (ML) with water vapour content of 4.8–5.7ppmv in altitudes of 18–19km altitudes in the lower stratosphere, and (2) ice layer (IL) with ice content up to 1.9eq.ppmv in altitudes of 17–18km in the upper troposphere around 06:30UTC on 8 August to the south of Kathmandu (Nepal). A Meso-NH convection-permitting simulation succeeds in reproducing the characteristics of ML and IL. Through analysis, we show that ML and IL are generated by convective overshoots that occurred over the Sichuan basin about 1.5 day before. Overshooting clouds develop up to 19km, hydrating the lower stratosphere of up to 20km with 6401t of water vapour by a strong-to-moderate mixing of the updraughts with the stratospheric air. A few hours after the initial overshooting phase, a hydration patch is generated, and a large amount of water vapour (above 18ppmv) still remains at even higher altitudes up to 20.5kma.s.l. while the anvil cloud top descends to 18.5km. At the same time, a great part of the hydrometeors falls shortly, and the rest sublimates. Meanwhile ice sediments out, the water vapour concentration in ML and IL decreases due to turbulent diffusion by mixing with the tropospheric air. As the hydration patch continues to travel toward the south of Kathmandu, tropospheric tracer concentration increases up to ~30 and 70% in ML and IL, respectively. The air mass in the layers becomes gradually diffused and it has less and less water vapour and ice content by mixing with the dry tropospheric air.

Keun-Ok Lee et al.
Interactive discussion
Status: open (until 15 Jan 2019)
Status: open (until 15 Jan 2019)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement
Keun-Ok Lee et al.
Keun-Ok Lee et al.
Total article views: 235 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
199 32 4 235 2 2
  • HTML: 199
  • PDF: 32
  • XML: 4
  • Total: 235
  • BibTeX: 2
  • EndNote: 2
Views and downloads (calculated since 20 Nov 2018)
Cumulative views and downloads (calculated since 20 Nov 2018)
Viewed (geographical distribution)  
Total article views: 227 (including HTML, PDF, and XML) Thereof 225 with geography defined and 2 with unknown origin.
Country # Views %
  • 1
No saved metrics found.
No discussed metrics found.
Latest update: 14 Dec 2018
Publications Copernicus